MXPA98007107A - Corrosion resistant metal coated and method to produce my - Google Patents

Abstract

A corrosion-resistant coated base metal, coated with a tin-zinc alloy, where the tin content plus the zinc content makes up a majority of the alloy. The coating alloy may also include one or more metal additives to improve the coating process and / or alter the properties of the tin and zinc alloy. A metal layer can also be applied to the surface of the base metal before applying the metal alloy coating.

Description

CORROSION RESISTANT METAL AND METOQ PJRA PRQPUClR E M? GMQ This application corresponds to a continuation-in-part of the co-pending patent application of the U.S.A. Serial No. 604,074 filed on February 20, 1996, which in turn is a divisional of the U.S. patent. No. 5,616,424 which in turn is a divisional of the US patent. No. 5,491,036 which in turn is a continuation-in-part of the US patent. No. 5,480,731, which in turn is a continuation of the US patent. No. 5,395,703 which in turn is a divisional of the US patent. No. 5,314,758. The patent of the U.S.A. No. 5,616,424 is also a divisional of the U.S. patent. No. 5,401,586 which in turn is a continuation-in-part of the abandoned patent application Serial No. 154,376 filed on November 17, 1993 which is a continuation of the US patent application. Abandoned Serial No. 042,649 filed April 5, 1993. US Pat. No. 5,616,424 is also a divisional of the U.S. patent. No. 5,491,036 which is a continuation-in-part of the US patent. No. 5,397,652, which is in turn a continuation-in-part of the abandoned patent application Serial No. 000,101 filed on January 4, 1993 which is a continuation-in-part of the US patent. No.5,314,758.

This application is also a continuation-in-part of co-pending patent application Serial No. 604,078 filed on February 20, 1996, which is a divisional of the US patent. No. 5,597,656, which in turn is a continuation-in-part of the US patent. No. 5,470,667, which is a continuation of the US patent. No. 5,401,586, which in turn is a continuation-in-part of the abandoned patent application Serial No. 154,376 filed on November 17, 1993, which in turn is a continuation of the abandoned patent application No. Series 042,649 filed on April 5, 1993. The present invention relates to the technique of a corrosion-resistant metal material and more particularly to a coated metal material, which is coated with an alloy, which is environmentally friendly, has long duration and is resistant to corrosion.

As background material such that the specification does not require specifying in detail what is known in the art, US Pat. Nos. 4,987,716 and 4,934,120 are incorporated herein by reference to illustrate metal roofing systems, of the type in which this invention may be used. The patent of the U.S.A. No. 5,455,122 is incorporated herein by reference to illustrate petroleum receptacles of the type in which this invention may be used. The patent of the U.S.A. No. 5,203,985 is incorporated herein by reference to illustrate a prior art electrocoating process for coating nickel on a carbon steel strip. The patents of the U.S.A. Nos. 5,314,758; 5,354,624; 5,395,702; 5,395,703; 5,397,652; 5,401,586; 5,455,122; 5,470,667; 5,480,731; 5,489,490; 5,491,035; 5,491,036; 5,492,882; 5,597,656 and 5,616,424 are incorporated herein by reference to illustrate various processes that may be employed to coat, treat and use the coated metal material. IBCKBWTfífí DB faft INVENTION The present invention relates to the technique of a corrosion resistant metal material such as a coated metal strip, this corrosion resistant metal material can be used in a wide variety of applications such as for example to be used for materials architectural, gasoline tanks, automotive products, equipment, etc .; however, the invention has wider applications and relates to various compositions of coating alloys based on tin and zinc and various novel methods and processes employed such as coating and / or heating (ie heating with flow, hot dip coating)., cut with air knife, metal spray), pretreatment of the metal material before coating, apply a layer of intermediate metal before coating and post-treating the coated metal material. Over the years, architectural materials such as metal roof systems, and sheet metal sheet metal roof systems, folding metal roofs in various sheet gauge thicknesses, have been employed. Metals such as carbon steel, stainless steel, copper and aluminum are the most popular types of metals used for these architectural materials. The term "stainless steel" is used in the technical sense and includes the use of chromium, coated or in alloy with a ferrous base. Architectural metal materials made of carbon steel were commonly treated with corrosion resistant coatings, to prevent rapid oxidation of the metal surface, thereby prolonging the life of the materials. A popular corrosion resistant coating for carbon steel is a leaded sheet coating. The leaded stainless steel and copper sheet lining is also produced, but it is much less predominant than carbon steel due to the natural corrosion resistance properties of stainless steel and copper. The leaded sheet coating has been the predominant and most popular coating for carbon steel materials, due to its relatively low cost, ease of application, excellent corrosion resistance properties and convenient coloration during weathering. Carbon steel coated with sheet metal or leaded sheet is used for gasoline tanks, roofing and building materials and for various other products. The coating for leaded sheet or alloy for coating for leaded sheet, is a term commonly used to describe an alloy containing approximately 80% lead and the remainder tin. The leaded sheet alloy is conventionally applied to metals by a hot dip process, wherein the base metal is immersed in a molten metal bath with leaded sheet by a continuous or batch process. Although metals coated with leaded sheet have excellent corrosion-resistant properties and have been employed in various applications, materials coated with leaded sheet have recently been challenged due to concerns of an environmental nature. Metals coated with leaded sheet contain a very high percentage of lead. Although the lead in leaded sheet alloys is stabilized, there is concern about lividing lead from the leaded alloy sheet. Public safety and environmental laws have recently been proposed and / or approved prohibiting or penalizing the user of materials that contain lead. Another disadvantage of leaded sheet coated materials is the smoothness of the leaded sheet layer. As noted, sheet metal coated with leaded sheet, commonly formed in various structures. The machines that bend the metal sheets periodically damage the leaded sheet lining during the bending process. The coating with leaded sheet is susceptible to damage due to the abrasive nature of the forming machines. The leaded sheet alloy has an additional disadvantage since the newly applied leaded sheet is very bright and highly reflective. As a result, the highly reflective coating can not be used in buildings or roof systems such as airports and military establishments. The leaded sheet coating eventually loses its highly reflective properties as the components within the leaded sheet coating are reduced (weathered); however, the desired amount of reduction takes approximately 1-1 / 2 to 2 years, when the leaded sheet coating is exposed to the atmosphere, thus requiring the leaded sheet metals to be stored for long periods of time, before to be employed in these special areas. The storage time is significantly prolonged when the materials coated with leaded sheet are stored in rolls and the rolls are protected from the atmosphere. The thin coating of carbon steel is a well-known process for use in the food industry. However, in the specialized art of architectural materials, a tin coating for architectural materials has not been used until recently as described in US Pat. No. 5,314,758. The most popular process for applying a coating from tin to carbon steel is an electrocoat coating process. In an electrocoating process, the coating thickness is very thin and typically ranges from 0.3 miera to 30 micras (1-2 x 10"sa 1.2 x 10 * 3 in.) In addition, the equipment and materials required to adequately electro-coat metallic materials are very expensive and relatively complex to employ. The expense of applying an electrocoated tin coating and thicknesses It is a disadvantage to use this procedure for building and roofing materials and in the automotive field, which creates an extremely thin layer with a network of small pitting that makes the strip generally unacceptable. The electro-coated strip can have a base layer produced in a short time and / or a covering coating to overcome the pitting problems inherent with an electrocoating coating.The tin-coated layer is also susceptible to flaking or scraping, when the coated strip is stretched and form in various components.Spings and / or dehiding or scraping of the coating is They are very problematic since tin is not electroprotective of steel under oxidizing conditions. Consequently, discontinuities in the tin coating result in corrosion of the exposed metal. Tin coatings have the additional disadvantage of having a highly reflective surface. As a result, materials coated with a tin coating can not be used in an environment where highly reflective materials are undesirable until the coated materials are further treated (ie painted) or the tin is given time to rust. The revetir metal base with zinc metal, commonly known as galvanization, is another popular metal treatment to inhibit corrosion. Zinc is a highly desirable metal for coating materials because of its relatively low cost, ease of application (ie hot dip application) and excellent corrosion resistance. Zinc is also electroprotective to steel under oxidizing conditions and avoids exposed metal, due to discontinuities in the zinc coating, which is subject to corrosion rapidly. This electrolytic protection extends away from the zinc coating on exposed metal surfaces by a sufficient distance to protect the exposed metal at the cutting edges, scratches and other coating discontinuities. With all the advantages of using zinc, zinc coatings have several disadvantages that make it undesirable for many types of construction applications and automotive components. Although zinc coatings will bond to many types of metals, the bond is not strong and results in the zinc coating exfoliating or peeling off building materials. The exfoliation of zinc or zinc oxide in a gas tank will seal the gas lines and filters. In addition, when fuel injection systems are used, small particles of zinc or zinc oxide will deactivate the injectors. Eetoe problems are unacceptable in the automotive field. In this way, galvanized strip is common, but it is not used for gaeoline tanks. Zinc does not bind well in standard stainless steel. Zinc does not form a uniform and / or thick coating in a hot dip process for stainless steel. As a result, coating discontinuities are usually found on the stainless steel surface. Zinc is also a very rigid and brittle metal and tends to crack and / or exfoliate when the materials are formed on site, ie press fit roofing, or when the fuel tank components are stretched. When the zinc begins to oxidize, the zinc coating forms a white powdery texture (zinc oxide). The popular gray, earth tone color is not obtained from pure zinc coatings. The electrocoating of a mixture of tin and zinc on a metal sheet is described in Japanese Patent Application No. 56-144738 filed on September 16, 1981. The Japanese patent application describes the coating of a metal sheet with a mixture of tin and zinc to form a coating less than 20 microns thick. The Japanese patent application discloses that after coating, there are pitting in the coating and exposing the coating to corrosion. The pitting is a result of the crystalline layer of the tin-zinc mixture that forms slowly during the coating process. The tin and zinc-laden atoms in combination with the atomic structure of the atoms and the crystal structure formed from a tin-zinc mixture prevents a uniform coating from being achieved on the coated steel sheet. Consequently, the crystalline deposits must be covered with a chromate or phosphoric acid to fill the pits and avoid immediate corrosion. The Japanese patent application discloses that a pre-coated layer of nickel, tin or cobalt is required on the surface of the steel sheet, such that the tin-zinc coated mixture is adhered to the steel sheet. These coating techniques, as described in the Japanese patent application, cost a tremendous amount of time and money and do not generate a commercially successful product. The Japanese patent application creates a network of pitting as well as the electro-coating process; therefore, the strip when stretched, creates large areas exposing the base metal. In this way, in the manufacture of gasoline tanks, the steel would be exposed directly to the combustion of stored liquid and will quickly undergo corrosion. The coating of steel articles by a hot-batch process with a mixture of tin, zinc and aluminum is described in US Pat. No. 3,962,501 issued June 8, 1976. The '501 patent discloses that the mixture of tin, zinc and aluminum resists oxidation and maintains a metallic luster. The '501 patent discloses that the coating is applied by immersing a steel article in the molten alloy bath for a prolonged period of time and subsequently removing the steel article.The' 501 patent also discloses that a bath of tin alloy and Molten zinc containing 3-97% zinc is very susceptible to surface oxidation, thus producing viscous oxides that cause severe problems with the process of submerging the steel articles in the molten alloy and subsequently removing the steel article. In addition, while the steel article is in the molten alloy, a large amount of foam is produced, resulting in heterogeneity of the coating and pitting.The '501 patent describes that the addition of up to 25 % aluminum to the tin-zinc mixture inhibits foaming during immersion of the steel article, prevents formation of Zn-Fe alloy, and prevents The formation of viscous oxide on the molten bath surface occurs. A batch process as described in the '501 patent subjects the surface of the article to different residence times in the molten alloy during immersion and removal of the article in the molten alloy and results in different coating thicknesses and coating properties in the article coated. The '501 patent also describes the formation of a highly reflective coating that can not be used in many construction applications. The treatment of a steel sheet by coating tin and zinc followed by thermal flow is described in US Pat. No. 4,999,258. The '258 patent discloses a steel sheet coated with a tin layer and subsequently applying a zinc layer, such that the ratio of zinc to tin is 2-30%. The layers coated with tin and zinc are then heated until the zinc forms an alloy with the tin. The coatings of tin and zinc form a very thin layer. Tin is applied at 0.2-1.0 g / m2 and zinc is applied at 0.01-0.3 g / m3. Due to the very thin coating thickness, the heating by flow of the tin and zinc coating layers only requires 2-5 seconds for adequate formation of tin and zinc alloy. The '258 patent also discloses that when less than 1% zinc is used, the beneficial effect of zinc is zero. However, when more than 30% zinc is used, the coating quickly undergoes corrosion under adverse environments. The '258 patent also discloses that a nickel coated layer is preferably applied to the steel sheet before applying the tin and zinc coated layers to improve the corrosion resistance. The thermo-treated tin and zinc layer can also be treated by passivating with a chromate treatment to further improve the corrosion resistance. The thin coating produced by the metal plate or coating coating process is highly susceptible to tearing when the coated metal material is formed into products such as automotive products and roofing products. A continuous process for electro-coating a carbon steel strip is described in U.S. Pat. No. 5,203,985. This patent discloses that the nickel is electrotransformed in a carbon steel strip in continuous motion. After the carbon steel has been nickel coated, the coated strip is covered by hot immersion with the molten zinc. The electrocoating of tin, tin-nickel or tin and zinc by an electrocoating process and subsequent formation of an intermetallic layer by thermal circulation of the coated layer, is described in U.S. Pat. No. 5,433,839. The problems associated with obtaining thick plate coatings is discussed in the '839 patent. The '839 patent discloses that the maximum coating thickness is 30 microns (1.2 x 10"3 inches) and preferably 3 microns (1.2 x 10" * inches). The complicated, slow and costly plate coating process is also described in the '839 patent. After the coating has been applied, the coating is heated by flow for a substantial period of time to form an intermetallic layer comprising tin, iron and chromium and to obtain a matte appearance (appearance of low reflectivity) on the surface of the coating. . The thickness of the intermetallic layer formed is preferably 0.7 miera (2.8 x 10 * inches). The limited coating thickness and the limited intermetallic layer thickness are an added disadvantage since the plated layer and the intermetallic layer can be damaged or removed when the coated sheet is formed into roofing materials, automotive parts or the like. Due to the various environmental concerns and problems associated with corrosion-resistant coatings applied to metallic materials, such as building materials and automotive products, and the problems associated with the accidental removal of the corrosion-resistant coating during formation of coated materials in various types of components such as roofing materials, automotive materials, etc. , there has been a demand for a material that is resistant to corrosion, that is environmentally friendly and resists damage during final component formation. CQMPIffiSQ pB l & INVE CONN The present invention relates to a product and method for producing an environmentally friendly, corrosion resistant metal material. More specifically, the invention relates to the coating of a base metal such as a metal strip, with a coating that forms a corrosion-resistant barrier in the base metal. According to the main feature of the invention, a base metal of stainless steel, carbon steel or copper coated with a corrosion-resistant metal alloy is provided. The metal clad alloy is an alloy that primarily includes tin and zinc. Other base metal compositions that have been coated include a base metal made of nickel, aluminum, titanium and bronze alloys. "Stainless steel" is used in its technical sense and includes a large variety of alloy metals that contain chromium and iron. Ferrous materials coated with chromium are also defined as stainless steel. During heating, the plate-coated chromium softens and intermixes with the ferrous strip to form a ferrous-chromium alloy. Stainless steel may also contain other elements such as nickel, carbon, molybdenum, silicon, manganese, titanium, boron, copper, aluminum and various other metals or compounds. Elements such as nickel can be subjected to short-term electroplating or flash evaporation (electro-coating) on the surface of the chromium-iron alloy or incorporated directly into the chromium-iron alloy, ie stainless steel. According to another aspect of the present invention, the base metal is plated, plated and subsequently heated by flow, metal spray or hot dip with an intermediate metal barrier before applying the alloy coating. metal to the surface of the strip. The intermediate metal barrier provides additional corrosion resistance, "substantially against halogens, such as chlorine. The metal barrier is preferably tin, nickel, copper or chromium. Other metals such as aluminum, cobalt, molybdenum, Sn-Ni or Fe-Ni are also used. The metal barrier is applied to the metal baee to form a very thin metal layer. Although the metal alloy coating provides excellent protection against most corrosion-producing elements and compounds, and forms a strong bond with the base metal, the inclusion of the intermediate metal barrier improves the characteristics of corrosion resistance and / or Bonding of the metal cladding alloy. The nickel is preferably subjected to short-term electroplating or plating on the base metal surface. The nickel coating of the base metal has been found to improve corrosion resistance, especially against compounds such as chlorine, which have the ability to penetrate the metal alloy coating and attack and oxidize the surface of the base metal, thereby weakening the union between the base metal and the metal alloy coating. It has been found that the nickel barrier provides an essentially impenetrable barrier to these elements and / or compounds that actually penetrate the metal alloy coating. Due to the very small amount of these compounds that penetrate the metal alloy coating, the thickness of the nickel barrier is preferably maintained at an ultra-thin thickness, while still maintaining the ability to prevent its components from attacking the base metal. The metal alloy coating and the thin nickel coating effectively complement each other to provide superior corrosion resistance. Tin, chromium and copper also form an intermediate metal barrier layer that improves the bonding of the metal alloy coating to the base metal. It has also been found that these metals improve the corrosion resistance of the intermetallic layer formed and inhibit the growth of the intermetallic layer of zinc which causes problems with foaming and deteriorates the mechanical properties, that is, cracking due to training. The copper is preferably coated in a plate on the surface of the base metal. The plate-coated copper layer is formed by passing the base metal through a standard electrocoating process or by adding copper sulfate to a pickling solution and stripping the copper strip. The chromium is preferably coated on the base metal plate by a conventional coating process. Preferably the tin is coated on the base metal by hot dip, plate coating or metal spraying. According to yet another aspect of the present invention, the plate-coated intermediate metal barrier layer is preheated and / or heated with flow before the tin and zinc alloy is applied to the base metal. The heating of coated metal causes an intermediate layer to form between the intermetallic layer and the base metal. This preheating process results in variation of intermetallic layer composition, resulting in improved corrosion and / or bond strength, In accordance with the broad aspect of the invention, the tin and zinc alloy is coated, plated and subsequently heated and / or heated with flow, hot dip coated, hot dip coated and subsequently subjected to to air blade, and / or spray-coated and / or spray-coated on the base metal surface.

In accordance with the broad aspect of the invention, the tin-zinc alloy primarily includes tin and zinc. The tin and zinc alloy preferably has a low lead content. Preferably, the alloy contains no more than about 1% lead, more preferably less than about 0.5 percent lead and even more preferably no more than about 0.05 percent lead. The alloy coating provides a corrosion resistant coating that protects the surface of the base metal against oxidation and which is environmentally friendly, thus immune from the biases associated with alloys containing lead. The tin-zinc alloy constitutes approximately 75 percent by weight of the alloy and preferably constitutes at least about 90 percent by weight of the alloy and more preferably at least about 95 percent by weight of the alloy and even more preferably when less about 98 weight percent and in particular at least about 99 weight percent of the alloy. The tin and zinc alloy has been found to be highly resistant to corrosion in the three main types of environments, rural, industrial and marine. Chlorine salts are common in marine environments while sulfur-containing compounds are common to industrial environments.

Rural areas are usually the least corrosive of all three environments. One of the important properties of the tin and zinc alloy is its excellent resistance to corrosion in all three main environments. The tin and zinc alloy has an opaque, low reflective surface; It has excellent properties at low temperature; resists degradation by solar energy; it can be easily formed in various structures; and can be installed in any type of environment. The excellent corrosion resistance of tin and zinc alloy is considered to result from the formation of a very stable, continuous, highly adherent and protective film on the surface. Because the tin and zinc alloy itself is reactive in the presence of oxygen or carbon dioxide, a beneficial oxide film is formed when the newly coated metal surface is exposed to air or moisture. A damaged oxide film can usually be healed again quickly. Due to the inertness of the oxide in most atmospheres, the tin and zinc alloy is considered environmentally safe and friendly. In addition, tin and zinc alloy is also considered a safe material to be used in the human environment. Tin and zinc alloy is considered a cost-effective material in reinforced structures in corrosive environments, in the tropics and other areas where buildings are exposed to strong hot marine winds, or corrosive vapors, as the tin and zinc alloy It is technically superior, highly reliable and environmentally safe in marine environments, compared to other types of construction materials. In addition to its excellent corrosion resistance, the tin and zinc alloy has low coefficient of thermal expansion, pleasant color and superior resistance to environments containing chlorine and aggressive oxidants where stainless steel, galvanized and aluminized materials exhibit significant localized corrosion that limits the total service duration. The tin and zinc alloy can be formed, stretched and welded. It can also be painted or colored by standard conversion coating procedures. According to another aspect of the invention, bismuth, antimony, nickel, lead, silver, arsenic, cadmium, manganese, chromium, aluminum, silicon, boron, carbon, molybdenum, vanadium, chromium, titanium, sulfur, potassium, cyanide, tellurium, phosphorus, fluoride, chlorine, bromine , nitrogen, copper, iron and / or magnesium are added to the tin and zinc alloy, to improve the mechanical properties of the metal alloy, improve the corrosion resistance of the metal alloy, improve grain refinement of the alloy metal, alter the color of the metal alloy, alter the reflectivity of the metal alloy, inhibit oxidation of the metal alloy during coating and / or in various types of environments, inhibit foam formation during coating, stabilize the metal alloy , improve the bonding of the metal alloy to various types of base metals and / or intermediate layers in the base metal, improve the flowability of the metal alloy during coating and / or reduce or inhibit the crystallization of the metal. Tin in the metal alloy. The alloying agents for the tin and zinc alloy can perform one or more functions in the alloy. The alleged functions of the alloying agents are described below; however, the alloying agents may have additional functions. The tin and zinc alloy preferably contains metal stabilizing agents. When the tin crystallizes, the binding of the tin-zinc alloy coating to the base metal weakens and results in peeling of the coating. The addition of small amounts of stabilizing metals, such as bismuth, antimony, cadmium, copper and their mixtures, prevents and / or inhibits the crystallization of tin. Bismuth, antimony, cadmium and / or copper also alter the mechanical properties (ie, formability, hardness, fluidity, strength, flexibility, durability) and corrosion-resistant properties of the metal alloy coating. It has been found that additions of nickel to the alloy provide additional corrosion protection to the tin and zinc alloy coating especially in environments containing alcohol, such as for gasoline tanks. The addition of nickel also alters the mechanical properties of the tin and zinc alloy. Copper can be added to the tin and zinc alloy coating, in addition to its stabilizing properties, to alter the mechanical properties of the alloy, to alter the color of the alloy, to alter the reflective properties of the alloy. Copper additions also improve the corrosion resistance of the metal alloy coating especially in marine environments. Additional magnesium alloy alters the mechanical properties of the alloy such as improving the flow properties or coating of the tin and zinc alloy, such that a more even and uniform coating is applied to the base metal during coating, especially in a heated process such as hot dip coating, heating with flow and / or metal spraying. Magnesium also reduces the anodic characteristics of the coating to additionally increase the corrosion resistance of the metal alloy coating. Magnesium also reduces oxidation of the molten metal alloy and / or reduces foaming during metal alloy coating when heated. Additions of aluminum to the tin and zinc alloy inhibit oxidation of the molten metal alloy and / or to reduce foaming in the metal alloy coating, when the alloy is heated (ie hot dip coating, heating with flow, metal spray). Aluminum also alters the reflective properties of the alloy and mechanical properties of the alloy. The aluminum further reduces the thickness of the intermetallic layer that is formed during the heating of the alloy coating (i.e., metal spray, flow heating, hot dip coating), to improve the formability of the coated base metal. Titanium additions to the tin and zinc alloy improve the grain refinement of the coated metal alloy, improve the mechanical properties of the alloy, such as increase the hardness and strength of the metal alloy, and improve the corrosion resistance of the alloy Titanium also prevents oxidation of the molten metal alloy and helps reduce foaming when the alloy is heated. Titanium also alters the reflective and color properties of the alloy. Titanium also improves the bonding properties of the alloy to the base metal and / or intermediate metal layer. Titanium also improves the corrosion resistance properties of the alloy. Additions of iron to the metal alloy increase the hardness and other mechanical properties of the alloy, and alter the color of the alloy. Lead additions increase the corrosion resistance of the alloy, alter the mechanical properties of the alloy, alter the color of the alloy and improve the bonding of the alloy to the base metal. The addition of chromium to the alloy improves the corrosion resistance of the alloy, alters the mechanical properties of the alloy and alters the reflectivity of the alloy. Additions of manganese to the alloy increase the corrosion resistance of the alloy, increase the grain density of the alloy and improve the bonding of the alloy. Additions of cadmium to the alloy alter the mechanical properties of the alloy, alter the color of the alloy, alter the reflectivity of the alloy, stabilize the alloy, improve the corrosion resistance of the alloy, alter the grain refinement of the alloy, They alter the oxidation of the alloy and improve the bonding properties of the alloy. Additions of silver to the alloy alter the mechanical properties of the alloy and alter the color and reflective properties of the alloy.

Additions of arsenic to the alloy, if any, alter the mechanical properties of the alloy. According to another aspect of the present invention, the base metal is a strip of metal that is designed to be coated with the tin and zinc alloy. The thickness of the metal strip is preferably not more than about .508 cm (0.2 inch) and preferably less than about .127 cm (0.05 inch) and preferably less than about .0762 cm (0.03 inch) and especially greater than approximately .0127 cm (0.005 inch). The thickness of the strip must not be too large to prevent the strip from being directed at high speed through the process of treatment, if any, and the reverse process. The metal strip, such as stainless steel, carbon steel or titanium, having a thickness greater than about 0.076 inch is very difficult to maneuver at high, economical speeds through the coating process. A "strip" is defined as metal that is shipped to the coating process in coils, as opposed to plates. In addition, obtaining thermal or temperature equilibrium of the strip during coating processes involving heat (i.e. flow heating, hot dip coating, metal spraying) to suitably form an intermetallic layer between the strip surface and the alloy dß coating, it is very difficult with a thick strip at high speeds. Heating the alloy by plate coating and subsequent heat flux is essentially equivalent to hot dip coating of the tin and zinc alloy in the base metal. Strip thicknesses that are less than approximately .0127 cm (0.005 inch) may break, as the strip passes at high speeds and / or are under tension when passing through the molten coating alloy. The thickness of the strip is also chosen such that the stretched or formed coated strip is strong and sufficiently durable for its intended purpose. When using the strip of stainless steel, strip of steel 304 or 316 that has a thickness of approximately .0127 to .0762 cm (0.005-0.03 inch) is preferable. According to another aspect of the present invention, the base metal is preferably pre-treated before applying the metal alloy coating. The pre-treatment process includes several stages for metals such as stainless steel or includes only a few stages for metals that are easier to clean and / or have a pre-activated surface. Commercial stainless steel usually has a passivated surface that is difficult to coat consistently and uniformly, especially in a high speed coating process. The pretreatment process of preference is similar to the process described in U.S. Pat. No. 5,395,702 and incorporated herein. The pretreatment process typically includes pickling and chemical activation of the base metal surface. The pickling process is formulated to remove a very thin surface layer from the base metal surface. Removal of a very thin layer from the base metal surface results in the removal of oxides and other foreign matter from the base metal surface, thereby activating the surface before applying the metal alloy coating. When coating stainless steel, it is especially important to activate the stainless steel surface in order to form a uniform coating and strong bond to the base metal. Stainless steel contains chromium and iron. The chromium on the stainless steel surface reacts with atmospheric oxygen to form chromium oxide. The chromium oxide film creates an almost impermeable barrier to protect the iron in the stainless steel from oxygen in the atmosphere, thereby inhibiting oxygen to combine with iron to form iron oxide. The chromium oxide film also forms a very tight and strong bond with stainless steel and is not easily removed. Although the formation of chromium oxide film is important in the corrosion resistance properties of stainless steel and is intended for commercial stainless steel, the commercial stainless steel chromium oxide film interferes with the binding of the alloy coating to the stainless steel surface, resulting in a coating bond for weak and peeling metal alloy. The surface activation of a stainless steel, as with other base metals, is achieved by removing the oxides on the surface of the base metal. The removal of a chromium oxide film from the stainless steel surface activates the stainless steel surface. The stainless steel test has revealed that the removal of the chromium oxide film improves the binding of the metal alloy coating and allows thick and / or uniform metal alloy coatings to be formed. The removal of oxide in other base metals also improves the bond and thickness of the metal alloy coating. The pickling process removes the noxious oxide layer, to facilitate the formation of a strong and uniformly bonded metal alloy coating. The pickling process slightly etches the base metal surface to remove a very thin layer from the surface. The etching speed is usually not the same across the surface of the base metal, thus forming microscopic valleys on the base metal surface, which increases the surface area for which the metal alloy coating is bonded to the metal base, The pickling process includes the use of an etching solution that removes and / or loosens the oxide from the base metal surface. The pickling solution contains various acids or combinations of acids such as hydrofluoric acid, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid and / or iso-humic acid. Hydrochloric acid solutions are preferably used to strip carbon steel. A specially formulated pickling solution should be used when the base metal is stainless steel, since the activation of a stainless steel surface is not adequately achieved by the use of prior art pickling solutions containing only sulfuric acid, nitric acid or hydrochloric acid. The specially formulated pickling solution contains a special combination of hydrochloric acid and nitric acid. This special dual acid formulation is found to be surprisingly effective in the rapid removal of chromium oxide from the stainless steel surface. The use of a dual acid solution is classified as aggressive base metal pickling. The dual acid composition of the pickling solution preferably includes about 5-25% hydrochloric acid and about 1-15% nitric acid and preferably about 10% hydrochloric acid and about 3% nitric acid. The dual acid results in limited etching of the stainless steel to increase the surface area without causing harmful pitting of the stainless steel surface. The control of the temperature of the pickling solution is important to provide a desired activity of the acid to remove the oxides from the metal surface. The temperature of the pickling solution is maintained at about 27 ° C (80 ° F) and usually between 49-60 ° C (120-140 ° F) approximately and preferably 53-56 ° C (128-133 ° F) . Higher concentration of acid and / or higher temperatures will increase the activity and aggressiveness of the pickling solution in the removal of oxides. The temperature of the pickling solution is preferably maintained when recirculating through heat exchangers. The pickling solution is preferably stirred to prevent the solution from ponding by varying in concentration, varying in temperature and / or to remove gas cavities that form on the base metal surface. The agitation of the pickling solution is carried out by placing agitators in the pickling tank and / or recirculating the pickling solution. Stirring brushes are preferably placed inside the pickling tank to agitate the acid solution and rub or scrub the base metal surface immersed in the acid solution. The base metal is preferably rubbed during the aggressive pickling process to facilitate the activation of the base metal surface. Rubbing the base metal surface increases and accelerates the removal of oxides from the base metal surface. Only one pickling tank is required to properly activate the base metal surface; however, additional pickling tanks may be used. The pickling tanks are approximately 7.62 m (twenty-five feet) in length; however, the size of the tank may be larger or shorter. The total time for pickling the base metal is preferably less than about 10 minutes, more preferably less than one minute and even preferably about 10 to 20 seconds, to properly activate the base metal surface. The base metal such as metal strip is preferably worked in a continuous process, the pickling tanks usually are 7.62 m (twenty-five feet) long and the metal strip is run through the pickling tanks at an approximate speed of .3 at 122 m / minute (1 to 400 feet / minute), preferably between about 15.2 to 76.2 m / minute (50 to 250 feet / minute) thereby subjecting the base metal to the pill solution in each tank of pickling, preferably for less than about one minute. If the base metal is metal strip, a preferable process is to unroll the metal strip from a roll of metal strip and guide the metal strip through a continuous process, ie to unroll the metal strip, process and cover the strip and roll up the coated strip. Once the base metal has been etched, the base metal is preferably treated in a chemical activation process. The chemical activation process also removes oxides and foreign matter from the base metal by subjecting the base metal surface to a deoxidizing agent. After the pickling process, very little rust, if any, is present on the base metal surface. The virgin surface is highly susceptible to forming oxides between the period of time and the base metal is removed from the pickling tank and coated with the tin and zinc alloy. When the base metal is sufficiently activated by only the pickling process, the chemical activation step is eliminated. Due to the difficulty in removing oxides from stainless steel base metals, a stainless steel base metal is preferably treated in the chemical activation process after the stainless steel has been treated in the pickling process.

Various types of deoxidizing solutions have been tested. Zinc chloride has been found as an excellent deoxidizing solution. Zinc chloride acts as both a deoxidizer and a protective coating for the formation of oxide on the base metal surface. The temperature of the zinc chloride solution is maintained at about room temperature of 15.6 to 32.2 ° C (about 60-90 ° F) and is preferably stirred to maintain a uniform temperature and solution concentration. Small amounts of hydrochloric acid are preferably added to the deoxidizing solution to further improve the removal of oxide. Preferably, hydrochloric acid is added to the zinc chloride when a stainless steel is treated. The time in which the base metal is subjected to the deoxidizing solution is usually less than about 10 minutes. The base metal, such as a metal strip, is preferably worked in a continuous process. The tanks with deoxidation solution are preferably approximately 7.62 m (25 ft) long and the base metal is subjected to the deoxidation solution preferably for less than about one minute. According to another aspect of the invention, the base metal is treated with an abrasive and / or absorbent material and / or is subjected to a solvent or other type of cleaning solution to remove foreign materials and oxides from the base metal surface before of pickling and / or chemical activation of the metal, The base metal such as a strip of metal that is taken out of a roll of base metal, commonly has foreign debris on the surface of the base metal. These wastes can consist of dirt, oil, glue, etc. Many of these foreign or foreign substances do not react with or are easily removable by the pickling solution, thus adversely affecting the removal of base metal Oxides. Treating the base metal with an abrasive and / or absorbent material removes these foreign substances from the base metal. The brushes are stationary or mobile with respect to the base metal. The brushes rough out the base metal surface to further improve the activation of the base metal during the pickling process. The roughened surface of the base metal allows the pickling solution to more easily attack the surface of the base metal. According to another aspect of the present invention, the pretreatment process preferably includes maintaining a low oxygen content environment before and / or subsequent to subjecting the base metal to the pickling process and / or chemical activation process and / or abrasion process. The maintenance of a low oxygen content environment inhibits the formation and / or reformation of oxides on the base metal surface. The low oxygen content environment can take several forms. Two examples of low oxygen content environments are the formation of a gas environment that has a low oxygen content relative to the base metal or the immersion of the base metal in a liquid environment that has a low oxygen content. Both of these environments act as screens against atmospheric oxygen and prevent and / or inhibit the formation of oxides. When the base metal is stainless steel, the low oxygen content environment is preferably maintained through the pretreatment process of the stainless steel base metal (i.e. abrasive / absorbent treatment, pickling treatment, pickling rinse treatment, chemical activation treatment, etc.), just before the coating of the stainless steel strip with the metal alloy coating. Base metals other than stainless steel base metals may be totally, partially or not subjected to a low oxygen content environment during the pretreatment process. The non-oxidized surface of a base metal is typical that it is highly susceptible to reoxidation when in contact with oxygen. By creating a low oxygen content environment with respect to the base metal, new oxide formation is inhibited and / or prevented.

Examples of low oxygen gas environment include nitrogen, hydrocarbons, hydrogen, noble gases and / or other non-oxidizing gases. Preferably, nitrogen gas is used to form the low oxygen gas content environment. Examples of a low oxygen content liquid environment include non-oxidizing liquids and / or liquids having a low content of dissolved oxygen. An example of the latter is hot water that is sprayed on the base metal surfaces; however, the base metal is submerged alternately in hot water. Hot water contains very low levels of dissolved oxygen and acts as a shield or protector against oxygen that forms oxides with the base metal. The spray action of the hot water removes any remaining pickling solution or deoxidizing solution from the base metal. The temperature of the hot water is maintained at about 37.8 ° C (100 ° F) and preferably at least about 43.3 ° C (not ° F) or higher, so as to exclude undesired dissolved oxygen. According to yet another aspect of the present invention, the base metal is rinsed with a liquid after leaving the pickling solution to remove the pickled solution from the base metal. After the base metal leaves the pickling solution, any remaining pickling solution in the base metal can continue to attack the base metal surface, resulting in pitting of the base metal. The pickling solution is preferably removed from the base metal by passing the base metal through a rinse solution such as water. If the rinse solution is water, the water preferably is maintained at about 26.7 ° C (80 ° F) and preferably at least about 43.3 ° C (110 ° F), to exclude dissolved oxygen from the water to avoid oxidation of the metal post-pickling base. The rinsing solution is preferably kept at its desired temperature by recirculating the rinsing solution through thermo-exchangers. Although the rinsing process primarily removes the pickling solution from the base metal, the rinsing process can also remove loose or loose oxides and / or debris from the base metal surface. If the base metal passes through a rinsing solution tank, the rinsing solution can remove small amounts of oxides due to the slightly acidic nature of the rinsing solution. As the rinse solution removes the base metal pickling solution, the pickling solution enters the rinse solution and acidifies the rinse solution. The slightly acidic rinse solution attacks sticky amounts of xides in the base metal, to further clean the base metal surface. The rinse solution is preferably agitated both to facilitate the removal of the pickling solution from the base metal and to dilute the removed pickling solution into the rinse solution. Preferred agitators include movable brushes which preferably contact the base metal. The rinse solution is preferably recirculated and diluted to avoid the occurrence of high levels of acidity. The alternative or additional rinse solution can be sprayed onto the base metal surface, to remove the pickling solution of oxides and / or debris. According to another aspect of the present invention, the tin and zinc alloy is applied to the base metal by a hot dip process, wherein the base metal is dipped or passed through the molten tin and zinc alloy, This way coating the base metal. The temperature of the molten alloy is at least about 231.7ßc (449 ° F). The metal alloy must remain above its melting point or inadequate coating will occur. Tin melts at approximately 232 ° C (450 ° F). The zinc melts at approximately 419.6 ° C (787 ° F). Metals such as iron, nitrile, aluminum, arsenic, cadmium, chromium, manganese, titanium, copper, magnesium, bismuth and / or antimonyWhen they are added to the metal alloy they alter the melting point of the metal alloy. For example, the alloy is heated to temperatures as high as approximately 538 ° C (1000 ° F), when the copper is added to the alloy. Higher or lower temperatures are used to accommodate the addition of other additive metals. In order to accommodate or adjust for high temperatures, the melting vessel (coating tangue) is made to support these higher temperatures such as increasing the thickness of the melting vessel and / or using special high-temperature melting materials for construction. of the fusion vessel. The temperature of the melting vessel is maintained several degrees above the melting point of the coating alloy, to prevent the molten alloy from solidifying when the base metal enters the melting vessel. According to another aspect of the present invention, the residence time of the base metal in the melting vessel is chosen to adequately coat the base metal and form the intermetallic layer. Preferably, the base metal is maintained in the melting vessel at least for about 5 seconds and less than about 2-10 minutes and preferably less than about 1 minute. The intermetallic layer forms a highly corrosion resistant layer, an intermetallic layer composition preferably includes tin, zinc and chromium and is formed by heating the tin and zinc coating in stainless steel, by heating the tin and zinc alloy in a strip Ferrous, this coating contains tin, zinc and chromium and / or by heating the tin and zinc alloy in a ferrous strip coated with chromium. The thickness of the intermetallic layer is very thin and preferably approximately 1-10 microns (3.0 x 105 - 3.9 x 10"* inches) in thickness.If the base metal is a strip of metal that is coated by a continuous process, the Metal strip is preferably passed through the metal coating process at a relatively constant speed.The speed of the metal strip is preferably kept from about .30 to 122 m / minute (1-400 feet / minute). Prior to the development of the current coated base metal, the corrosion-resistant material was made by (a) a hot batch process with submerged descending, holding for a preselected time and removing a metal sheet item up and out up and out of an electrolysis tank or (b) in a process of moving discrete stretches of a sheet or a base metal in continuous motion in and out of the electrolysis tangue in a direction longitudinal to the sheet. The process can be very expensive and reguire expensive equipment and complicated electrical conduction networks. The batch hot dip process is defined as a process in which a discrete base metal is immersed in a molten metal coating bath, held in the bath for a pre-selected time and then removed (ie moved upwards). ) from the molten metal bath. Another type of batch hot dip process is where a stretch of sheet material is moved to a molten metal casing bath, often in transport rollers, retained in the melting vessel and then removed from the melting vessel. The current movement of the sheet material section in and out of the molten metal is already vertically or longitudinally guided by several guide rollers located in the melting vessel. The batch hot dip process is accomplished with a variety of equipment used to move the sheet material in the molten metal bath, to keep the sheet in the molten metal for a certain time and then to move the sheet material from the container of fusion, either vertically or longitudinally in a trajectory dictated by guide rollers. Metal sheets that are vertically immersed (ie the most common "hot dip" process) exhibit coating runoff and scratching and poor or poor coating distribution. Discrete pieces of sheet metal that wind longitudinally inside and outside the melting vessel exhibit poor coating distribution, primarily due to interferences from the guide rollers, which are necessary to direct the discrete metal sheets inside and outside the fusion vessel. The driving force for movement of the sheet in and out of the melting container is due to the effect of displacement of the rollers in the melting container, these rollers are in contact with the coating metal. The same problems recognized by Ohbu in U.S. Pat. No. 3,962,501 (Nippon Steel) are found when conventional batch hot dip processes are used. It was found that the simple addition of the metal, such as aluminum as illustrated in Ohbu '501, does not solve the failure of the alloy to adhere or bind or create a completely acceptable appearance. The coated sheets form a coated material, but do not solve all the problems that have occurred with batch coating processes. Nippon Steel apparently found that the use of aluminum was not the solution, since subsequently Nippon Steel submitted an application for electro-coating as described in Japanese Publication No. 56-144738 (1993), The coating processes of the present invention for coating the base metal with the tin and zinc alloy form a laminar product completely different from the previous efforts employed in a discrete hot batch or standard batch process. For example, the coating of a base metal by a continuous hot dip process includes coating a base metal such as a continuous strip of relatively undefined length and moving the strip continuously through a molten tin and zinc alloy in a melting vessel in a curvilinear path thereby regulating less, if necessary, guide rollers (without impulse rollers) so that the sheet metal material is no longer submerged in, holds and then removes from the molten metal in a melting vessel as was done before using the normal hot dip process. This continuous hot dip process produces a product superior to a product coated by the hot dip, dip, hold and remove process as illustrated in the Ohbu '501 patent and other processes for hot dip coating by batch laminar material. The coating process of the present invention inherently generates a different final product for products coated in a batch hot dip process which includes immersing a sheet of material in a melting vessel, keeping the sheet in the melting vessel and then Remove the sheet from the melting container. The continuous coating process of the present invention allows the base metal to dictate the path in the molten alloy bath and does not give the results of the inlet, retention and exit type of the hot batch process of discrete sheet material or other metal articles. The coated base metal, coated by the continuous coating process of the present invention, also produces a coated base metal that is superior to coatings by traditional plates. The coating process of the present invention has distinct advantages over traditional plate coatings, such that the coating process is simpler, forms a greater coating thickness, produces substantially fewer pitting or surface discontinuities in the coating surface, it forms a stronger bond coat, more quickly forms a coated base metal and / or can coat an alloy having a wide variety of metal additives. If the base metal cladding is by a hot dip process, the base metal cladding such as the metal strip, is produced by unwinding a metal strip from a strip roll and continuously passing the strip at a relatively constant speed through a melting vessel containing an alloy for coating with molten metal. Selective immersion of metal articles or a piece of sheet material does not involve a continuous strip-type hot dip process. A base metal coated in a continuous strip type hot dip processWhen cut into discrete sheets, it is easily distinguishable from metal sheets coated by a hot dip batch process. The coating thickness in a hot dip process is a time function that is resident or submerged in the base metal in the molten metal. As described in the Galland patent of the U.S.A. No. 4,015,950, the coating thickness increases the longer the metal material in the molten metal is held. In a batch hot dip process, the immersion residence time is different from various regions in the sheet metal material. When the metal sheet is hot dipped in a batch process, the leading edge of the metal sheet is the first to enter the molten metal and the last to leave the molten metal. The additional residence time of the leading edge of the metal sheet and the adjacent areas of the metal sheet cause the coating to form a thicker coating on the metal sheet in these regions. These variances in coating thicknesses are easily distinguishable from uniform coating thicknesses, constituted by a continuous strip-type hot dip process of the present invention. In addition, long immersion times to make the coating uniform, constitute an excessively thick coating, thus requiring the coating to be rectified or removed by an oxidizing agent. These additional processing steps make the product different. In addition, the removal of coating to form a uniform thickness will expose different coating compositions as illustrated by Galland '950. These exposed coating compositions are different from coatings that are produced by continuous strip hot dipping processes. The resulting rectified coating has a lower corrosion resistance and other properties than a non-rectified outer coating surface. In any aspect, this post-treatment of the coating to obtain uniform thicknesses, if possible in the metal sheet, will be visually different from a base metal coated in a continuous strip-type hot dip process of the present invention. Regardless of how the coating alloy is formed by a batch hot dip process, the growth of the intermetallic layer will not be uniform since the growth is a function of residence time in the melting vessel. A base metal coated in a continuous strip type dip process can coat quickly, efficiently and economically with a metal alloy coating which has a uniform thickness and produces a superior product. In a continuous strip type hot dip process, the residence times of the strip surface on both sides of the strip and the strip edges in the molten bath are the same. The uniformity of residence time in the molten metal results in uniform coating thicknesses on the base metal surface and uniform intermetallic growth. This gives superior union. The residence time of the base metal in the melting vessel is controlled by the strip speed and the length of the melting vessel. The non-uniform coating thickness disadvantages commonly associated with products formed in a batch hot-dip process are overcome by coated products in a continuous strip-type hot dip process of the present invention. Differences in the coating characteristics of coated products in a batch process and the products coated in a hot dip process of continuous strip type, are easily apparent by visual inspection of the metal coated surface and visual inspection of the cross section of the coated surface. The corrosion resistance test also reveals the differences in products coated by a continuous strip type hot dip process or a batch hot dip process. The surface quality of coated products by hot dip process of continuous strip type and by batch hot dip process, it is also visually apparent. A sheet of metal coated in a batch hot dip process, by immersing the discrete metal sheet in a melting vessel and subsequently removing it from the melting vessel, will exhibit runoff or coating scratching as the sheet is removed from the melting vessel . The runoff or scratching of the coating is due to the fact that gravity acts on the molten coating alloy as the sheet is slowly removed from the melting container. This scratching adversely affects the surface morphology of the coated sheet by forming heterogeneous surfaces and non-uniform thickness across the surface of the coated metal sheet. The coating run-off or scratch also results in the metal alloy coating accumulating with respect to the leading edge of the metal sheet and reduced coating thicknesses with respect to the trailing edge of the sheet. Further processing of the submerged sheet metal by a batch hot dip process is necessary to pair the metal alloy coating and reduce the build-up of the coated metal alloy relative to the leading edge of the sheet metal. A product that is formed by a hot dip process of the continuous strip type of the present invention overcomes the problem of runoff and scratching inherent with using a batch hot dip process. A base metal coated in a continuous strip type hot dip process resides in the melting vessel for a uniform time by maintaining a constant strip velocity as the base metal continuously passes through the melting vessel. The constant strip velocity not only maintains a constant residence time of the strip in the melting vessel, but also creates a uniform coated surface. As the base metal passes through the molten metal at a constant velocity, the molten metal relative to the strip either adheres to the moving strip as the coating of the moving strip is sheared. This shearing effect results from the viscosity of the molten metal alloy and the speed at which the base metal moves through the melting vessel. For a certain strip velocity and viscosity of molten metal alloy, a constant shearing effect is applied to the surface of the moving strip. The constant force of the shearing effect smoothes the coated surface and facilitates the formation of a constant coating thickness. A sheet metal material coated by a batch hot dip process does not take advantage of the shearing effect, thus resulting in coating runoff and scratching and a less efficient bonding. In addition, process sheets for hot batch immersion include surface flux inclusions, caused by retention and then removed through the molten metal surface. In a continuous strip type hot dip process, unrestricted growth of the metal alloy coating on the surface of the strip is controlled thereby reducing the incidence of surface defects and thereby improving the coating uniformity in comparison with a coated metal sheet in a hot dip batch process. The uniformity of the coating thickness on and through the base metal surface is an important factor that affects the quality and performance of the coated base metal. The use of a continuous strip-type hot dip process for coating a base metal provides surfaces of metallurgical uniformity by controlling the growth of the metal alloy coating on the strip surface, thereby reducing the formation of surface irregularities. Additionally, the metallurgical characteristics of the intermetallic layer formed by a continuous strip-type hot dip process are superior to an intermetallic layer formed by a batch hot-dip process. The growth of the intermetallic layer depends on the composition of the sheet or strip of metal, the composition of the coating alloy and the time / temperature history of the growth and solidification of metal alloy coating on the metal strip or sheet. The growth and solidification of the metal alloy is best controlled in a continuous strip type hot dip process, thereby forming a visible and physically superior coated metal base material, as compared to a metal sheet coated in a process hot dip batch. The sheet coated by the continuous strip type hot dip process has been found to have superior coating bond to the metal base sheet. As a result, products coated by a continuous hot dip process are different from products coated by a batch hot dip process, since the following characteristics are different and superior: 1) Uniformity of coating (weight and thickness) 2 ) Surface appearance 3) Smoothness 4) Texture control 5) Intermetallic phase control (growth and uniformity) In summary, base metal coated in a continuous strip hot dip process of the present invention, produces a metal sheet having superior coating uniformity (weight and thickness), superior stalographic structure, superior surface appearance, superior smoothness, superior size of large crystals on the surface, superior orientation and minor surface defects and the composition of different phases is superior compared to metal sheets coated in a batch hot dip process. In addition to the surface appearance and uniformity of the thickness, the formability is also improved due to a more uniform thickness. In general, thicker coatings provide greater protection against corrosion, while thinner coatings tend to give better formability and weldability. Thinner coatings with uniformity of thickness are characteristics of a sheet having the novel tin and zinc alloy and produced by a continuous strip-type hot dip process of the present invention. According to another aspect of the present invention, the coating of the base metal by a hot dip process, preferably includes the use of a flux case, whereby the base metal passes through the flux case before move to the melting vessel containing the molten metal. The flux box preferably contains a flux having a lower specific gravity than the molten metal alloy, so the flux floats on the surface of the molten alloy. The flux removes residual oxides from the base metal surface, protects the base metal surfaces against oxygen, until the base metal is coated with the molten metal alloy, inhibits the formation of viscous oxides to the point where the base metal enters. the molten metal alloy and inhibits foaming in the base metal. The flux of preference is zinc chloride solution. The flux also preferably contains ammonium chloride. The flux solution contains about 30 to 60% by weight of zinc chloride, and up to about 40% by weight of ammonium chloride, and preferably about 50% of zinc chloride and about 8% of ammonium chloride.; however, the concentrations of the two fluxing agents are varied accordingly. According to yet another aspect of the present invention, the coating of the base metal by a hot dip process preferably includes a melting vessel heated by heating coils, heating rods, gas jets, etc. Preferably, the melting vessel is heated by at least one jet of gas directed at least to one side of the melting vessel. Heating coils and heating rods are preferably used to heat the metal directly in the melting vessel containing the tin and zinc alloy. Gas jets are used as an alternative to heat the molten metal alloy, especially if the alloy includes large amounts of zinc. These alloys containing zinc have been found to rapidly attack through the heating elements submerged in the alloy. According to another aspect of the present invention, the base metal coating by a hot dip process, preferably includes the use of a protective material on or on the surface of the molten metal alloy in the melting vessel. The protective material preferably has specific gravity that is less than the molten metal alloy, such that the protective material floats on the surface of the molten metal alloy. The protective material shields the molten metal alloy from the atmosphere, thus preventing oxides from forming on the molten metal alloy surface. The protective material also inhibits foaming in the coated base metal, as the coated base metal exits the melting vessel. When the protective material is palm oil, the melting point of the metal alloy should be less than about 343.3 ° C (650 ° F) which is the point of degradation of the palm oil. For coating alloys having higher melting point temperatures, special oils, fluxes or other materials and / or special cooling processes are used for the protective material. According to another aspect of the present invention, the coated base material is subjected to an air knife process. In an air knife process, the coated base metal is subjected to a high speed gas. The high-velocity gas releases the overcoated metal alloy coating from the base metal, abrades the coated metal alloy coating over the base metal to cover the pitting, if any, improves the grain size of the metal alloy coating, reduces lumps or ribs in the alloy coating that forms on the surface of the base metal and / or reduces the coating thickness of the coated metal alloy. The gas with high velocity is air or an inert gas that does not oxidize with the coated metal alloy. Preferably, the gas is an inert gas such as nitrogen, sulfur hexafluoride, carbon dioxide, hydrogen, noble gases and / or hydrocarbons. When an inert gas is used in the air knife process, and the air knife process is used in conjunction with a hot dip coating process, the protective material on the surface of the molten metal alloy in the container Melt (ie palm oil) is preferably removed, since the inert gas prevents foaming, viscous oxide formation in the region in which the inert gas contacts the molten metal alloy in the melting vessel. Inert gas with high velocity also decomposes and displaces any foam or viscous oxides from the surface of the molten metal alloy into the melting vessel in the region in which the inert gas contacts the molten metal alloy, thereby forming a region Free of viscous oxide - essentially free of foam for the coated base metal is removed from the melting vessel. The gas with high velocity of the air knife process is preferably directed to both sides of the coated base metal and in a direction which is preferably not perpendicular to the surface of the coated base metal. According to yet another aspect of the present invention, the thickness of the metal alloy coating is controlled by one or more sets of coating rollers. The coating rollers form a coating layer based on uniform metal alloy and even on the base metal. The coating rolls are preferably used in conjunction with the coating process such as a hot dip coating process, an air knife process, a flow heating process and / or a metal spray process. When a hot dip process is used, and when palm oil is used as a protective material on the surface of the melting vessel, the coating rolls are preferably partly or completely immersed in the palm oil. Palm oil facilitates in qualitative distribution, the coating layer of metal alloy on base metal. The thickness of the metal alloy coating on each base metal side resulting from the use of the coating rollers is at least about 0.00254 mm (0.0001 inch) and preferably about 0.00762 - 1.27 mm (0.0003). 0.05 inch) and more preferably .0254 - .0762 mm (0.001-0.003 inch) approximately. According to another aspect of the present invention, the thickness of the metal alloy coating when used in a hot dip process can also be regulated by the residence time of the base metal in the melting vessel, the temperature of the alloy of metal in the melting vessel and the use of an air knife process in conjunction with the hot dip process. The thickness of the alloy coating that is covered in the base metal will also depend on the speed at which the base metal travels through the alloy. A base metal velocity of approximately 122 meters / minute (400 feet / minute) results in high shear forces that interfere with proper coating resulting in an inadequate or defective alloy coating of the base metal. When an air knife process is employed in conjunction with the hot dip process, the coating rolls are preferably used in conjunction with the air knife process or alternatively, the coating rolls are completely removed. According to yet another aspect of the present invention, spray jets are preferably used to spray the molten metal alloy onto the base metal to cover the base metal and / or ensure a uniform and continuous coating on the base metal. The metal spray jets are preferably placed adjacent to the coating rollers to ensure complete coating of the base metal. The metal spray jets spray molten metal alloy on the coating rollers and / or on the base metal. In one embodiment, the metal spray jets are placed upstream of the coating roller and / or an air knife. In another embodiment, the metal spray jets apply the metal coating as the base metal passes through the coating rolls. The coating rolls both press against the base metal and fill any pitting or uncoated surfaces in the base metal and control the coating thickness. After the base metal has been covered by a coating process, which involves heat, the coated base metal is preferably cooled. The cooling of coated metal base is achieved by spraying the coated base metal with a cooling fluid such as water at room temperature and / or immersing the coated base metal in a cooling liquid such as room temperature water. The cooling of the coated base metal is usually less than one hour and preferably less than a few minutes. When the alloy coating cools at different speeds, different grain sizes and grain densities are formed. Slow cooling of the alloy coating results in larger grain size, lower grain densities and a highly reflective surface. A rapid cooling of alloy coating produces fine grain size, increases grain density and a less reflective surface. Small grain sizes and higher grain densities produce a stronger bond with the base metal and greater resistance to corrosion. For a method of spraying or injecting liquid, water is sprayed on the coated base metal. In this cooling process, the base metal is preferably directed through the cold water jet sprays by a camel back guide. The camel back guide is designed so that only the edges of the coated base metal contact the guide. By minimizing the contact of the coated base metal with the guides, the amount of coating alloy accidentally removed from the coated base metal is reduced. The camel back guide is also designed to allow jets of water to cool the underside of the coated base metal. For an immersion process, the cooling water is usually stirred to increase the cooling rate of the base metal coating. The temperature of the cooling water is preferably maintained at suitable cooling temperatures, by recycling the water through thermo-exchangers and / or replenishing the water. The cooling water is preferably not deoxygenated before cooling the coated base metal coating. The oxygen in the cooling water oxidizes with the metal coating alloy during rapid cooling, resulting in a lightly discolored coated base metal surface having reduced reflection. According to another aspect of the present invention, the coated base metal is passed through a leveler, whereby the uniformly alloyed metal alloy is molded to the base metal and a final coating thickness control is obtained. The leveler preferably consists of a plurality of rollers. The coated base metal is passed through the rollers to smooth the metal alloy coating on the base metal. The base metal is preferably held at a tension as it passes through the leveler. According to another aspect of the present invention, the base metal is a strip that is coated and subsequently rolled into coils for further processing in high-speed presses, such as is used in the automotive field. Alternately, the coated metal strip is sheared, after it has been cooled or leveled. Since the coated metal strip is in continuous motion, the shearing device preferably travels near and at the same speed as the coated base metal to properly shear the moving strip. When the base metal is not cut, the base metal is wound onto a roll of a coated strip for ease of transport and / or for use in subsequent treatments and / or forming (i.e. roofing materials). The continuous processing of the strip of installations from roll to roll in the effectiveness in cost, efficiency and ease of coating a base metal. According to another additional aspect of the present invention, the base metal is processed in a passivation solution such as a specially formulated acid solution after coating the base metal to expose the intermediate layer which is formed between the base metal surface of the base metal. the strip and the coating alloy during a coating process involving heat. Removal of the metal alloy coating layer is described in U.S. Pat. No. 5,397,652 which is incorporated. According to another aspect of the present invention, the coated base metal is treated with a weathering agent to accelerate the weathering and discoloration of the metal alloy coating. Metal alloy coatings contain high concentrations of tin, it is common that they are highly reflective. To reduce the reflectivity of these metal alloy coatings, the weathering material is applied to the metal alloy coating to oxidize the metal alloy coating surface and reduce the reflectivity of the metal alloy coating. The weathering material is an asphalt-based paint that causes an accelerated weathering of the metal alloy coating when exposed to the atmosphere. Asphalt-based paint significantly decreases the weathering time of the metal alloy coating to less than a year. The preferred asphalt paint is an oil-based paint that includes asphalt, titanium oxide, inert silicates, clay, carbon black or other carbon-free and anti-settling agent. The asphalt-based paint is preferably applied to a relatively thin thickness to form a semi-transparent or translucent layer on the metal alloy coating. The thickness of the asphalt-based paint is in the range of approximately .00635 to .127 mm (0.25 to 5 mils (0.00025-0.005 inch)) and is preferably approximately .0254- .0508 mm (1 to 2 mils (0.001 -0.002 inch)). One sees? Since the translucent paint has been applied to the coated base material, the weathering material is dried, preferably by air drying and / or by heating lamps.

According to yet another aspect of the present invention, the metal alloy coating composition is such that the coated base metal is formed on site without cracking and / or peeling off the metal alloy coating. Stabilizers and / or metal additives are used to prevent the coating alloy from becoming too stiff and brittle. According to yet another feature of the present invention, the metal alloy exhibits excellent welding characteristics, such that various electrodes including lead and non-lead electrodes can be used to weld the coated metal. The primary objective of the present invention is to provide a metal alloy which has high corrosion resistance properties. Another object of the present invention is to provide an alloy of metal made from a majority of tin and zinc. Still another object of the present invention is to allow an intermediate barrier of thin metal to be applied to the surface of the base metal before applying the metal alloy coating. Yet another additional object of the present invention is to provide a base metal treated with a metallic coating which is not highly reflective.

Still another object of the present invention is to provide a metal alloy that is essentially lead-free. Another object of the present invention is to provide a base metal coating by a continuous, hot immersion process, wherein the base metal has a controlled residence time in a molten bath as the base metal moves longitudinally through the bath . Yet another object of the present invention is to provide a coated base metal that is shaped and sheared to form various construction and roofing components, gasoline tanks and other formed base metal that are subsequently assembled on site or in a forming facility. Still another object of the present invention is to provide a coated base metal that is preformed into roof sheets and subsequently joined in place by either pressed joints, welded joints or solder joints in waterproof joints. Yet another object of the invention is to provide a coated base metal that is corrosion resistant, economical to produce and capable of forming in a variety of structures while not containing objectionable amounts of lead.

Another object of the present invention is the addition of a coloring agent to the metal alloy to alter the color of the metal alloy. Still another object of the present invention is the addition of a metal additive to the metal alloy to improve the corrosion resistance of the metal alloy. The present invention has additional purpose the addition of a metal additive to the metal alloy to improve the metallic characteristics of the metal alloy. The present invention has another objective in adding a metal additive to the metal alloy to positively affect the grain refinement of the metal alloy. A further object of the present invention is the addition of a metal additive to the metal alloy to reduce oxidation of the molten metal alloy. A further objective of the present invention is the addition of a metal additive to the metal alloy to inhibit the crystallization of the metal alloy. Still another object of the present invention is the addition of a metal additive to the metal alloy to improve the bonding characteristics of the metal alloy.

Another object of the invention is to provide a metal alloy that is welded by conventional tin-lead solders or lead-free solders. Still another object of the present invention is the addition of a metal additive to improve the mechanical properties of the metal alloy. Still Another object of the present invention is to provide a metal alloy coating having superior corrosive characteristics that allow a m. { The thin cladding of the metal alloy to the base metal is the same as that required for an 80% lead and 20% tin (terne) alloy coating with a high lead content. Still another object of the present invention is to provide spray jets which spray the metal alloy coating over the coating rollers and / or base metal surface to remove uncoated surfaces in the base metal. Another object of the present invention is to provide a base metal coating coated with a weathering material to accelerate the matte finish of the surface of the metal alloy coating. Yet another additional object of the invention is to provide a coated base metal that does not require intentional oxidation to produce a non-highly reflective surface. Still another object of the invention is to use an air knife process, to control the thickness and quality of the metal alloy coating on the base metal. Still another object of the present invention is the formation of an intermetallic layer between the base metal and the metal alloy, this intermetallic layer is formed by heating the coated metal alloy and forming a strong bond between the base metal and the alloy coating. of metal . Another object of the present invention is to provide pickling of a base metal before coating the base metal with a metal alloy coating to form a strong alloy bond. Still another object of the present invention is to provide chemical activation of the base metal, to improve the bond between the base metal and the metal alloy. Still another object of the present invention is to provide the reduction of oxygen interaction with the base metal during the pretreatment of the base metal before coating the base metal.

Still another object of the present invention is to provide cooling of the metal alloy coating, to form fine grains of high density which produce a stronger bonding, more corrosion resistant, bleached coating. Another object of the present invention is to provide the abrasive treatment of the base metal surface before pickling and / or chemically activating the base metal. Another object of the present invention is to provide spray jets which cast metal alloy coating onto the coating rollers and / or base metal surface to remove uncoated surfaces in the base metal. Another object of the present invention is to provide the coating of the base metal coating with a weathering material to accelerate the matte finish of the surface of the metal alloy coating. A still further objective of the present invention is to provide a coated base metal that does not require intentional oxidation to produce a non-highly reflective surface. Another object of the present invention is the indirect heating of the melting container without using heating coils or heating rods. Still another object of the present invention is the use of an air knife process to control the thickness and quality of the metal alloy coating on the base metal. Still another object of the present invention is a base metal with a surface with previous color that is consistent and quite similar to base metal coated alloy of 80% lead and 20% tin (terne) with weathering, no lead at all. Another object of the present invention is to allow a coated base metal to be subjected to an oxidizing solution to remove the metal alloy coating of the base metal and expose the intermetallic corrosion resistant layer. Another object of the present invention is to allow the metal alloy to passivation solution to form a passive coating which is highly resistant to corrosion on the surface of the metal alloy. The present invention has as an additional objective, to allow producing a coated base metal highly resistant to corrosion that is economical to produce.

These and other objects and advantages will be apparent to those skilled in the art upon reading the detailed description of the invention set forth below. BRIEF DESCRIPTION OF THE DRAWINGS Figures la-Ib are a cross-sectional view of the hot-dip metal alloy coating process of base metal, as defined in the present invention. Figure 2 illustrates a cross-sectional view of an alternate process for cooling the hot dip-coated metal alloy base metal of the present invention; Figure 3 illustrates a cross-sectional view of an alternate embodiment, where metal spray jets are employed during the hot dip coating of the base metal; Figure 3a illustrates a cross-sectional view of an alternate embodiment wherein air blades are employed during the hot dip coating of the base metal; Figure 4 is a schematic side view illustrating a preferred embodiment for cooling the coated base metal by hot dip using cooling water spray jets; Figure 5 illustrates a cross-sectional view of an alternate embodiment where abraded treaters are employed in conjunction with a low oxygen content environment for pre-treatment of the base metal; Figure 6 is a front view of a camel back guide; Figure 7 is a perspective view of the melting vessel heated by gas torches; Figure 8 is a cross-sectional view of a coated base metal illustrating the intermetallic layer; and Figure 9 illustrates a cross-sectional view of an alternate embodiment, wherein a base metal is unwound and coated upon passing the base metal into a molten alloy casting vessel and then subjecting the base metal to coating rollers and to an air knife process and then rewinding the coated strip in a coil. DESCRIPTION PB THE PREFERRED MODALITY Now referring to the drawings, wherein the illustrations are for the purpose of showing preferred embodiments of the invention only and not for the purpose of limiting the same, reference is first made to Figures 1-lb illustrating the preferred embodiment of the invention. process of hot dip coating a metal alloy on a base metal. The metal alloy is a corrosion resistant coating to prevent the coated base metal from corroding prematurely when exposed to the atmosphere. The tin and zinc alloy contains a large percentage by weight of tin and zinc. The metal alloy is highly resistant to corrosion, abrasion resistant, foldable, weldable and environmentally friendly. The metal alloy is bonded to the base metal to form a durable protective coating that is not easily removed. The amount of protection for corrosion resistance that is provided by the metal alloy coating is of paramount importance. The invention will now be described with particular reference to a base metal in the form of a metal strip; however, it is understood that the invention has a much wider application and the special coating of tin and zinc can be applied to a wide variety of prepared and configured base metals. The invention will now be described with particular reference to a hot dip coating process; however, the coating alloy can be applied by a variety of coating processes such as plate coating, plate coating and subsequent flow heating, metal spraying and / or hot dip coating and subsequent metal spraying and / or treatment with air knife. The metal strip, such as carbon steel and stainless steel, oxidizes when exposed to the atmosphere. Over a period of time, the oxidized steel, commonly referred to as corrosion, begins to weaken and disintegrate the steel. The coating of the metal strip with the metal alloy acts as a barrier to the atmosphere, which prevents the metal strip from being subjected to corrosion. Although the metal alloy is oxidized when exposed to the atmosphere, the oxidation rate is significantly slower than the oxidation rates of metal strip such as copper, carbon steel and stainless steel. By coating the metal strip with the metal alloy, the life of the metal strip lasts for many years. The folding capacity of the metal alloy is also important when the coated metal strip is to be formed. For architectural materials, such as roofing materials, roofing materials are formed into various structures and are usually folded to form seams, to bond the roofing materials together to form a roofing system. A roofing material coated with a metal alloy that forms a rigid or brittle coating on the roofing material usually cracks or prevents the roofing materials from being properly configured. In addition, a roofing material coated with a metal alloy that is brittle or rigid, prevents or even prevents the roofing material from bending properly, to form the seams necessary to connect the roofing materials together. The metal alloy must be welded since the roof panels are commonly welded together. The metal alloy coating of the present invention meets all these requirements by containing a majority of tin and zinc and low levels of lead that produce a highly corrosion resistant metal coating with relatively high bending capacity and are welded to other materials . The metal strip is preferably carbon steel, stainless steel or copper; however, the metal strip made of alloys of aluminum, bronze, nickel, titanium and the like, has also been successfully coated. When the metal strip is stainless steel, the strip is preferably 304 or 316 stainless steel. Metal strip, preferably used to apply a hot dip coating of a corrosion-resistant metal alloy.

As illustrated in Figures la-Ib, strip 12 is a strip of stainless steel that is provided with a large metal roll 10. The thickness of strip 12 is approximately .127-5.08 mm (0.005-0.2 inch). . Preferably, strip 12 is less than about 1.27 mm (0.05 inch) and about .381 mm (0.015 inch). The strip 12 is unwound from the roller 10 at speeds that are preferably less than about 122 m / minute (400 feet / minute) and preferably between about 21.33-76.2 m / minute (70 to 250 feet / minute). The speed of the strip is finally chosen such that the residence time of the strip in the melting vessel 70 is less than about 10 minutes and preferably less than about one minute. The strip guides 13 are placed through the hot dip coating process to properly guide the strip 12 through each treatment process. After the metal strip 12 is unwound from the metal roll 10, the strip 12 is optionally pre-treated as described in US Pat. No. 5,395,702 or immediately coated with an intermediate metal layer 143. Preferably, a strip of carbon steel and stainless steel is pretreated to activate the surface of the strip before applying the intermediate metal layer 143.

The abrasion treatment apparatus 14, in the form of wire brushes 16, is moved by motors. The wire brushes are placed in contact with the strip 12 for removing foreign objects from the strip 12 and for initially etching and / or mechanically removing oxides from the surface of the strip 12. The abrasion treatment apparatus 14 can take any shape, but preferably it is directed against the strip 12, to provide the necessary friction between the brushes 16 and the strip 12, for proper cleaning of the strip 12. Preferably, there is an abrasion treatment apparatus 14 located on the upper and lower surfaces. bottom of strip 12, such that appropriate treatment of strip 12 is achieved. The abrasion brush 16 is preferably made of a material having a greater hardness than the strip 12, such that the abrasion brush 16 will quickly not wear out and will properly remove foreign material and / or pre-etch the strip 12. The abrasion brush 16 preferably rotates in an opposite direction to the moving strip 12, to provide additional abrasion to the strip 12. The strip 12 is preferably cleaned with solvents or cleaners such as organic solvents or alkaline cleaners to further remove. undone The abrasion treatment apparatus 14 and / or the cleaning treatment is an optional treatment process and is preferably removed for certain types of metal strip such as for titanium strip. Preferably, the carbon steel and the stainless steel are treated with the abrasion treatment apparatus 14. Once the strip 12 passes through the abrasion treatment apparatus 14, the strip 12 enters an environment of low moisture content. oxygen gas 20. The low oxygen gas content environment 20 is formed by surrounding the strip 12 with gas having a low oxygen content 22. These gases include nitrogen, hydrocarbons, hydrogen, noble gases and / or other gases that do not contain oxygen . Preferably, the gas having a low oxygen content 22 is nitrogen gas. The nitrogen gas surrounding strip 12 acts as a barrier against oxygen in the atmosphere and prevents oxygen from forming oxides in strip 12. The low oxygen content environment is an optional process and is preferably used for stainless steel strip . Strip 12, after leaving the low oxygen content gas environment 20, enters the pickling tank 30. The pickling tank 30 has an approximate length of 7.62 m (25 feet) and of sufficient depth to completely submerge. strip 12 in the pickling solution 32. The pickling tank can be longer or shorter depending on the speed of the metal strip.

The pickling solution contains various acids or combinations of acids such as hydrofluoric acid, sulfuric acid, nitric acid, hydrochloric acid, phosphoric acid and / or iso-humic acid. The pickling solution 32 is preferably a hydrochloric acid solution. The hydrochloric acid solution includes at least about 5% hydrochloric acid. The chromium oxide on the surface of the stainless steel strip is not easily removed and requires an aggressive pickling solution to remove surface oxides from the stainless steel strip to activate the surface of the strip. A dual acid solution of hydrochloric acid and nitric acid is used to aggressively strip the stainless steel strip. The concentration of nitric-hydrochloric acid within the aggressive pickling solution 32 is about 5-25% hydrochloric acid and about 1-10% nitric acid and preferably about 10% hydrochloric acid and about 3% nitric acid. The pickling solution 32 is maintained at a temperature of at least about 26.7 ° C (80 ° F) and preferably about 48.9-60 ° C (120-140 ° F), such that the pickling solution 32 is maintained. in a relatively highly reactive state, to adequately remove the oxides from the surface of the strip 12. The pickling solution 32 also provides minor etching of the surface of the strip 12, which removes a very small surface layer from the strip 12. Pickling tank 30 contains at least one agitator 34. Stirrer 34 is provided to agitate pickling solution 32 to maintain a uniform solution concentration, maintain a uniform solution temperature and break up any gas cavities that form in strip 12. The agitator 34 is constituted by an abrasive material which both agitates the pickling solution 32 and facilitates the removal of oxides from the strip 12. The agitator 34 is preferably made from a material It does not react with the pickling solution 32. The agitator 34 is preferably placed to directly contact the moving strip 12 to improve rust removal. The metal strip preferably is not in the pickling solution for more than about 5 minutes to avoid pitting the strip. Preferably, the pickling time is less than about two minutes and more than about five seconds. A vent for pickling solution 36 is placed on the pickling tange 30 to collect and remove vapors of acid and other gases escaping from the pickling tank 30. In an alternate embodiment of the present invention, strip 12 immediately enters an environment of low oxygen gas content 20, after leaving the pickling tank 30. After the strip 12 leaves the pickling tank 30, the strip 12 is essentially absent from any surface oxides and is highly susceptible to oxygen oxidation in the atmosphere. A gas environment with low oxygen 20 protects the surface of strip 12 against atmospheric oxygen and prevents any oxides from forming. Stainless steel strip is highly susceptible to re-oxidation of the strip surface. A low oxygen content environment 20 is preferably a low oxygen content gas environment, similar to that previously discussed. The pickling solution 32 is removed from the strip 12 in the rinse tank 40. The rinse tank 40 contains a rinse solution 42 which is hot water. The water in the rinse tank 40 is deoxygenated by heating the water to about 37.8 ° C (100 ° F) and preferably about 43.3 ° C (110 ° F). Due to the slightly acidic nature of the rinse solution 42, the rinse solution 42 removes small amounts of oxides that still exist on the surface of the strip 12. The rinse tank 40 is approximately 6 meters (20 feet) long , but may be longer or shorter depending on the speed at which the strip 12 travels. The rinsing solution 42 is preferably agitated to facilitate the removal of pickling solution 32 from strip 12 and to improve removal. of small amounts of oxide. The agitators preferably are placed in the rinsing tank 40, to be in contact with the moving metal strip 12, to improve the removal of stripping solution from the strip 12. For metal strip different from the stainless steel strip, the pickling process and the rinsing processes are processes optional Various types of metal strips will require stripping and rinsing more or less than other types of metal strips. The pickling process and the rinsing process are also preferably used for carbon steel strip. After the strip 12 leaves the rinsing tank 40, the strip 12 enters the low oxygen content liquid environment 50. The low oxygen content liquid environment 50 consists of at least two injection nozzles 52, one located on each side of the strip 12. The injection nozzles 52 inject a liquid having low oxygen content 56, on the surface of the strip 12, to prevent the oxygen from reacting with the surface of the strip 12. The injection nozzles 52 also remove any additional pickling solution 32 remaining on the strip 12 after the rinsing tank 40 has come out. The liquid having a low oxygen content 56 consists of hot water having an approximate temperature of 43.3 ° C (110 ° F). The low oxygen content environment is an optional process for strip material other than stainless steel. Strip 12, when leaving the low oxygen content liquid environment 50, enters the chemical activation tank 60. The chemical activation tank 60 contains an activating chemical solution 62, which also removes any oxides that remain on the surface of the strip 12. Preferably, the chemical activating solution 62 is a deoxidizing agent that includes a zinc chloride solution maintained at a temperature of at least 15.5 ° C (60 ° F). The zinc chloride within the chemical activation tank 60 not only removes persistent oxides in the strip 12, but the zinc chloride acts as a temporary protective layer that prevents oxide formation in the strip 12, until the strip 12 enters the melting vessel 70. The temperature of the zinc chloride solution is preferably maintained at about 15.5 to 32.2 ° C (60 to 90 ° F) and stirred to maintain a uniform solution concentration. Small amounts of hydrochloric acid are preferably added to the deoxidizing solution, to further improve the evolution of oxides. Preferably, the zinc chloride solution contains at least about 5% zinc chloride. The chemical activating solution preferably includes from about 5 to 50% zinc chloride and about 1 to 15% hydrochloric acid. Strip of metal different from stainless steel, that is titanium strip, preferably derives the chemical activation process. In addition, metal strips such as aluminum can optionally be treated with the chemical activation process as a substitute for the pickling and / or rinsing processes. The metal strip 12, preferably is coated with an intermediate metal layer, after leaving the chemical activation tank 60 and the application of the intermediate metal barrier layer is an optional process, not shown, but preferably used for Stainless steel strips before hot dip coating. The intermediate metal layer is preferably a single phase metal, tin, nickel, chromium or copper. The thickness of the layer is maintained such that it is an ultra-thin layer with no more than about 3 microns (1.18 x 10"4 in) and preferably has a thickness that is about 1 to 3 microns. metal strip can be used as a substitute for pre-treatment of the strip As previously discussed, the metal strip such as stainless steel strip, requires pretratars to activate the surface of the strip, ie remove surface oxides before applying the metal alloy coating The intermediate metal layer applied, such as tin, chrome, nickel or copper, forms a strong bond with the stainless steel strip and the carbon steel strip, whether the surface of the strip has been activated or not. The intermediate metal layer has also been found to be tightly bound to the hot-dip coated metal alloy. Even though the passivated stainless steel strip has been successfully coated with an intermediate layer and subsequently has been coated with the tin and zinc alloy without activating the surface of the strip, the bonding of the intermediate metal layer to the strip is improved and the formation of a better intermetallic layer results when the surface of the strip is activated in the pre-treatment process described above. The intermediate metal layer 143 has also been found to be tightly bound to the hot dip zinc and tin alloy. The intermediate metal barrier layer is applied by an electrocoating process. The metal strip 12 is continuously passed through the electrolytic tank 40 which contains an electrolyte solution 42. The plating of the intermediate metal barrier layer is performed by standard electro-coating techniques and additional details for these techniques are not will be discussed more. The coated layer can also be heated by flow or pre-treated before hot dip coating. The heating by flow of a strip coated on a plate with a metal such as tin, causes an intermetallic layer to begin to form before the strip enters the molten coating alloy. The formation of the intermetallic layer ensures that a relatively high concentration of coated metal atoms are contained in the intermetallic layer. The preheating of the coated strip, similar to the preheating of the strip, facilitates the formation of the intermetallic layer especially for thick strip. The application of an intermetallic layer of tin to the surface of the metal strip has been found to advantageously change the composition of the intermetallic layer, especially for metal coating alloys containing large amounts of metals other than tin such as aluminum alloy. Tin and zinc coating. Tin has been found to be a very important component of the intermetallic layer with respect to bonding and folding capacity of corrosion-resistant metal alloy. Concentrations higher than tin in the intermetallic layer are obtained when the intermediate layer of tin is applied to surfaces of the metal strip before hot dip coating. The intermediate layer of tin also prevents the formation of a thick zinc layer and an intermetallic layer. The formation of zinc intermetallic compounds and the intermetallic layer occurs at speeds that depend on the nature of the metal strip (ie, passivated composition) and the temperature / time history of the coated strip during the coating process. The intermetallic growth of zinc causes problems with foaming and mechanical properties of the strip (i.e., stiffness of the coated layer) which results in poor coating quality or cracking of the coating during forming and bending. Extensive growth of the intermetallic zinc layer formations results in localized corrosion, coating cracking, coating operations problems and adversely affects the performance of the coated strip in its particular application. The intermediate tin layer is preferably coated by standard electro-coating techniques, hot-dip coated in a molten tin bath or sprayed with molten tin once the tin layer has been applied to the surface of the strip. 12 metal, the tin layer can be heated by flow or pre-heated before hot dip coating. The heating by flow of the strip coated with tin, causes an intermetallic layer to begin to form before the strip enters the molten coating alloy. The formation of the intermetallic layer has been found to result in a relatively high concentration of tin atoms in the intermetallic layer. When the tin-coated coating is heated by flow, the coating thickness is preferably at least about 2 microns, such that a sufficiently thick coating exists for adequate flow heating. It has been found that an intermediate layer of chromium on the surface of the metal strip advantageously changes the composition of the intermetallic alloy, especially when the metal strip does not contain chromium. Chromium is preferably coated by standard electro-coating techniques. Chromium has been found to combine with tin to form a highly corrosion-resistant barrier. Metal strip such as carbon steel coated with chromium, results in the formation of an intermetallic layer containing iron, chromium and tin. This intermetallic layer composition has been found to be highly resistant to corrosion, especially after the intermetallic layer has been oxidized as described in U.S. Pat. No. 5,397,652 incorporated herein by reference. A modification of the invention includes heating by flow or preheating the chromium coated layer, before coating with hot dip. The coating of a ferrous metal such as carbon steel converts the carbon steel into stainless steel as discussed above. An intermediate layer of copper on the surface of the strip improves the corrosion resistance properties of the coating alloy. The intermediate copper layer is preferably formed by standard electro-coating techniques or by the addition of copper sulfate in the pickling solution. Copper also colors the metal alloy to reduce the reflectivity of the metal alloy. The copper coating on the strip before the hot dip coating also allows the copper to be incorporated into the molten alloy and the intermetallic layer without having to keep the copper in molten form. The copper-coated strip can also be pre-heated before the hot dip coating to improve the formation of an intermetallic layer. Copper coating also inhibits the intermetallic formation of zinc to coat zinc containing alloys. An intermediate layer of nickel on the surface of the strip improves the corrosion resistance of the coated strip. The intermediate layer of nickel is preferably applied by standard electro-coating techniques. The coating of the nickel metal strip is also used to eliminate the need for the strip to be pre-treated and activated before the hot-dip coating. The bond between the metal alloy coating and the nickel layer is surprisingly strong and durable and thus inhibits the metal alloy coating that peels especially when the metal strip is formed. The coating of the metal strip with the nickel layer is very convenient when the metal strip is used in an environment that has high concentrations of fluorine, chlorine and other halogens. Although the coating of the metal alloy significantly reduces the corrosive effects of halogens on the metal strip, it has been found that by placing a thin layer of coated nickel or plate and between the metal strip and the metal alloy coating , the corrosive effects of halogens have been further reduced. It has also been found that the nickel plated strip improves the corrosion resistance properties of the intermetallic layer during hot dip processes, when combined with the components of the intermetallic layer. The nickel plate coating also inhibits intermetallic zinc formation to coat zinc containing alloys.

After the strip 12 leaves the electrolytic tank 40, the strip 12 and before the strip 12 is coated with a molten metal alloy 76, the strip 12 enters the flux box 72 located in the melting vessel 70. The box of flux 72 contains a flux 74 having a specific gravity less than that of molten metal alloy 76. Flux 74 consists of a solution of zinc chloride and ammonium chloride. Preferably, the flux 74 contains about 50% zinc chloride and about 8% ammonium chloride. The flux 74 is the final pre-treatment process of the strip 12 for removal of any remaining oxides and the surface of the strip 12. The flux box 74 also acts as an oxygen barrier and prevents surface oxides from forming. of the molten metal alloy, these oxides interfere with the proper coating of the metal strip. In another embodiment of the present invention, the strip 12 is preheated before entering the melting vessel 70. It has been found that the metal strip of a thickness less than about 0.762 mm (.03") does not require Warm up to properly coat the metal strip and properly form the intermetallic layer Metal strip thicknesses greater than approximately 0.762 mm (.03") are defined as thick strip and this thick strip may not require pre-heating. The pre-heating of the thick metal strip facilitates the strip reaching the equilibrium temperature with the temperature of molten metal in the melting vessel 70. The thin metal strip has been found to rapidly reach the equilibrium temperature in this way coating adequately and forming the intermetallic layer. Upon leaving the flux case 72, the strip 12 enters the molten alloy 76. The melting vessel 70 is maintained at a temperature of several degrees above the melting point of the metal alloy 76, to prevent solidification of the metal 76 as the strip 12 enters the melting vessel 70. The molten metal alloy 76 in the melting vessel 70 is maintained at a temperature preferably at least about 5.6 ° C (10 ° F) above the melting point of the melt. the metal alloy 76. The melting vessel 70 is preferably approximately 3.05 to 30.5 meters (10 to 100 feet) long to provide adequate residence time for the metal strip as it passes through the melting vessel . Longer melting vessel lengths are used for very fast moving strips. The melting vessel 70 is divided into two chambers by the barrier 80, in order to prevent the protective material 78, such as palm oil, from being dispersed over the total surface of the molten metal alloy 76 in the container in fusion 70. The molten metal alloy 76 is an alloy of tin and zinc. The molten alloy 76 is an alloy of tin and zinc. The tin-zinc metal alloy coating is a special combination of tin and zinc. It has been found that the addition of zinc and an amount of at least about 10% by weight of the tin and zinc alloy, the corrosion resistance of the metallic tin and zinc coating is improved in various types of environments, compared to a protective coating essentially composed of tin. The tin content of tin and zinc metal alloy is significant to result in an alloy of tin and zinc instead of a galvanized metal coating. The tin is at least about 15% by weight of the alloy and preferably about 15 to 90% by weight of the metal alloy coating. The zinc content of the metal alloy is preferably the main component of the tin-zinc alloy; however, the zinc in the tin and zinc alloy can be as low as about 10% by weight of the metal alloy and is in the range of about 10 to 85% by weight of the metal alloy. The content of tin plus zinc of the tin and zinc alloy, preferably it is greater than about 75% by weight and more preferably at least about 80%. Tin and zinc metal alloy coatings can also be used to contain up to about 90% by weight, up to about 95% by weight, up to about 98% by weight, up to about 99% by weight of tin plus zinc. As is well known in the art, a tin-zinc metal alloy system is a combination of two primary elements, which form a composite alloy in which each of the constituents of tin and zinc maintain their own integrity (structure or composition) with a phase that is a matrix that surrounds different globules or phases of the second phase metal. The system of tin and zinc is a dual extract of globules or metal phases, each globule or phase is different from the other in structure or composition. For an alloy of tin and zinc as required by the invention, different globules or zinc phases are formed in a matrix comprising a eutectic mixture of tin and zinc. The carbons or phases and the matrix define layers or regions through the coating layer. A tin-zinc eutectic mixture is a tin-rich mixture, containing approximately 91% by weight of tin and approximately 9% by weight of zinc. For the defined tin rich matrix or phase and the zinc rich globules or phases that form a tin and zinc alloy, the zinc should constitute about 10% by weight of the alloy. Zinc in excess of about 10% by weight of the alloy causes the zinc to precipitate out of the eutectic tin-tin mixture (tin-rich phase) and form zinc globules or phases within the eutectic tin and zinc matrix (rich in zinc). zinc). The tin content of the alloy should constitute about 15% by weight of the alloy, such that there is a sufficient amount of tin in the alloy to form the eutectic tin and zinc matrix, to give the characteristics required to the coating. Metal additives can be added to the tin and zinc alloy in small quantities, without disturbing the tin and zinc structure of the alloy. The content of the metal additive must be controlled so that the metal additives are mixed with the metal alloy within the eutectic tin and zinc matrix (rich in tin) and / or the zinc rich globules or phases without forming a third, fourth, fifth, etc., phases in the alloy and / or interrupting the eutectic matrix of tin and zinc (rich in tin) or the globules or phases rich in zinc. When determining the composition of the tin and zinc alloy of the present invention, the environment in which the coating is to be used must be considered. In some situations, high tin content is beneficial to limit the amount of zinc rich globules or phases in the tin and zinc alloy. In other situations, it has been found that larger amounts of zinc should be added to increase the number and / or size of the zinc-rich globules or phases within the tin and zinc alloy. The addition of small metal additives such as bismuth, antimony, nickel, lead, silver, arsenic, cadmium, manganese, chromium, aluminum, chromium, titanium, copper, iron and / or magnesium or others to the binary system, does not interrupt the matrix or eutectic phase of tin and zinc (rich in tin) or the zinc rich globules or phases of the tin and zinc coating. The tin and zinc coating is obtained by a continuous hot dip process on a thin metal strip. By using this method to obtain the tin and zinc characteristics of the invention, the advantages of the tin and zinc coating can be achieved with coating thicknesses of less than about 0.762 mm (.003"). Only in this way can the strip be The formulation of tin and zinc is oxidized to form a color coating that closely matches the alloy of 80% lead and 20% gray tin (terne) popular, weathered earth tone color. Large percentages by weight of zinc in the tin and zinc alloy, does not cause the coating to become too rigid or fragile.The tin and zinc alloy allows the coated material to form or bend and resist cracking or breaking, as it is revealed by extensive experimentation performed on tin and zinc coatings having zinc content of about 10 to about 85% by weight. year and zinc contains 10 to 85% by weight of zinc and essentially the rest of tin, produces an acceptable malleable coated material. Zinc concentrations of 10% by weight or greater also stabilize tin in the tin and zinc alloy to resist tin crystallization. The malleability of tin and zinc alloys containing high concentrations of zinc apparently results from the unique distribution of tin and zinc within the tin-zinc alloy. According to another embodiment of the present invention, the metal alloy contains small amounts of other metals to modify the mechanical properties of the metal alloy to contribute to the strength of the metal alloy, to the corrosion resistance of the alloy of metal, to the color of the metal alloy, to the stability of the metal alloy and to the coating properties of the metal alloy. The secondary metals preferably constitute less than about 25 weight percent of the metal alloy and more preferably less than about 10 weight percent of the metal alloy, even more preferably less than about 2 weight percent of the alloy of metal, and in particular less than about 1 weight percent of the metal alloy. According to another embodiment of the invention, the tin and zinc alloy contains bismuth, antimony, copper and / or cadmium. The bismuth contained in the metal alloy is in the range of about 0.0 to 1.7 weight percent of the alloy and preferably up to about 0.5 weight percent, and especially up to about 0.01 weight percent. Antimony is added to the metal alloy in amounts of from about 0.0 to 7.5 weight percent, and more preferably up to about 1.0 weight percent. The copper content is added to about 5 weight percent of the metal alloy. Preferably, the copper content of the metal alloy does not exceed about 2.7 weight percent, and more preferably up to about 0.05 weight percent. When copper is added to the metal alloy, the copper content is added in amounts of about 0.005 to 2.7 weight percent and more preferably about 0.01 to 0.1 weight percent. Preferably copper is added to the molten metal alloy in the brass form. The metal alloy preferably contains antimony, bismuth, cadmium and / or copper since these metals inhibit or prevent the tin in the metal alloy from crystallizing, resulting in dehulling of the metal alloy from the metal strip. Tin begins to crystallize when the temperature drops below approximately 13.2 ° C (56 ° F). Only small amounts of antimony, bismuth, cadmium and / or copper are required to stabilize tin and prevent tin from crystallizing. Amounts of at least about 0.001 to 0.01 weight percent have been found to adequately inhibit tin crystallization, which results in the metal alloy flaking off prematurely. For tin and zinc metal alloys, the amount of metal stabilizer that adequately inhibits the crystallization of the tin within the tin and zinc coating is as low as at least about 0.001 to 0.004 weight percent of the metal alloy. Antimony also improves the corrosion resistance of the metal alloy. The addition of bismuth improves the mechanical properties of the metal alloy such as folding capacity, hardness and strength of the metal alloy. Only small amounts of antimony or bismuth are required to stabilize tin and inhibit tin from crystallizing. According to another embodiment of the invention, small amounts of other metals such as nickel, lead, silver, arsenic, cadmium, manganese, chromium, aluminum, chromium, titanium, iron and / or magnesium are added to the tin alloy coating. and zinc to alter one or more properties of the tin and zinc alloy. When iron is contained in the metal alloy, the iron content preferably does not exceed about 1.0 weight percent of the metal alloy, and more preferably constitutes less than about 0.002 weight percent. The addition of the metals to the tin and zinc alloy preferably constitutes very small weight percentages of the metal alloy coating and preferably does not exceed more than about 5% of the metal alloy and more preferably is less than about 2%. of the metal alloy coating and even more preferably less than about 1% of the metal alloy coating and especially less than about 0.5 weight percent of the alloy. The nickel content of the tin and zinc metal alloy coating, preferably does not exceed about 5.0 weight percent. Higher concentrations of nickel make the coated materials difficult to form. Preferably, the nickel content does not exceed about 1.0 weight percent and more preferably about 0.001 to 0.1 weight percent and especially particularly about 0.001 to 0.005 weight percent. The magnesium content does not exceed about 5.0 weight percent of the metal alloy. The magnesium is preferably not more than about 1.0 weight percent of the metal alloy and more preferably 0.0 to 0.1 weight percent of the metal alloy. The titanium content of the preferred metal alloy does not exceed about 1.0 percent by weight of the metal alloy. Preferably, the titanium content of the metal alloy is from about 0.0 to 0.2 percent by weight and especially about 0.0 to 0.05 percent by weight of the metal alloy. The amount of aluminum added to the metal alloy, preferably does not exceed about 5.0 weight percent of the metal alloy. Preferably, the aluminum content of the metal alloy is about 0.001 to 0.5 percent by weight, more preferably 0.001 to 0.01 percent by weight, and especially particularly 0.001 to 0.005 percent by weight. Preferably, if the manganese is added, it is added in an amount of at least about 0.0001 weight percent and up to about 0.1 weight percent of the metal alloy. The lead content is kept below about 1.0 weight percent, to eliminate any environmental concerns associated with the metal alloy. Preferably, no more than about 0.1 weight percent is added to the metal alloy, and especially less than about 0. 06 percent by weight of lead is included in the alloy. In the preferred embodiment illustrated, the metal strip is not preheated before coating. A strip of thin metal does not require preheating as thin metal strips quickly heat to the temperature of the molten metal alloy. As the metal strip reaches equilibrium with the temperature in the melting vessel, an intermetallic layer is formed between the metal strip and the metal alloy coating. Metal strip up to approximately a thickness of .762 mm (0.03 inch) is classified as a thin metal strip, and does not require preheating before coating. The non-preheated thin metal strip forms a high quality intermetallic layer 140. The absence of a preheating step simplifies the coating process and also makes the production of the coated metal strip more economical to manufacture. Although not required, the thin metal strip has been preheated and this preheated strip still forms an intermetallic layer during the coating. Metal strip that has a thickness of about .762 mm (0.03 inch) is considered a thick metal strip and is preferably pre-heated before coating. Thick metal strips do not always reach the right temperature balance to form a suitable intermetallic layer. Preheating the thick metal strip makes it easier to reach or approach a temperature equilibrium in the metal strip, so that a suitable intermetallic layer is formed. As illustrated in Figure 8, as the strip passes through the melting vessel 70, an intermetallic layer 140 is formed which helps in creating a strong bond between the strip 12 and the metal alloy coating 142. The intermetallic layer is It is formed by metal alloy coating atoms which are molecularly intertwined with atoms on the surface of the strip 12, as the temperature of the metal strip approaches the temperature of the molten metal alloy in the melting vessel. The migration of the metal alloy coating atoms in the surface layer of the strip 12 results in the formation of the intermetallic layer 140. The thickness of the intermetallic layer is very thin and varies between about 1 to 10 microns. For the coating of a strip of stainless steel, the intermetallic layer 140 is an alloy at a molecular level primarily of chromium, iron and tin, ie Cr-Fe-Sn. The intermetallic layer 140 can include nickel, zinc, iron, copper, chromium, tin, aluminum, lead, manganese, silicon, cadmium, titanium, silver, arsenic, sulfur, tellurium, magnesium, antimony, bismuth, hydrogen, nitrogen and / or oxygen and small amounts of other elements or compounds depending on the composition of the strip 12 and the molten alloy 76. The intermetallic layer 140 can be considered as a transition layer between the strip 12 and the metal alloy coating 142. The intermetallic layer 140 is responsible for the strong bond between the metal alloy coating 142 and the strip 12. The intermetallic layer also forms a corrosion resistant layer. The residence time of the strip 12 in the melting vessel 70 is preferably less than three minutes and preferably less than one minute and in particular about 5 to 30 seconds. The residence time is chosen to suitably form the intermetallic layer. As illustrated in Figure 7, the melting vessel 70 is preferably heated by four heating jets 71 directed on the outer sides of the melting vessel 70. The heating jets are preferably gas injection nozzles which heat the alloy of molten metal 76 in the melting vessel 70 at least at the temperature required to melt the alloy of the coating. The temperature of the melting vessel is preferably about 231.6 to 537.8 ° C (449 to 1000 ° F) and will depend on the composition of the coating alloys. Higher temperatures can be set for different coating alloys, in this manner, additional heating injection bogies, heating rods and / or heating coils, can be used to heat the melting vessel 70. As discussed above, the strip 12 is preferably not preheated as the strip enters the mold. melting vessel 70, in this way melting vessel 70 is maintained at least several degrees above the melting point of metal alloy 76 to prevent the molten alloy from solidifying as the strip enters the molten alloy. Now with reference to Figures 2 and 3, the strip 12 preferably passes between at least one set of coating rollers 82 before leaving the melting vessel 70. The coating rollers 82 maintain the coating thickness of the desired metal alloy in the strip 12, and remove any metal alloy excess 76 of the strip 12. The thickness of the metal alloy coating on the strip 12 preferably is maintained between about 0.00254 - 1.27 mm (0.0001 to about 0.05 inch) and especially about about 0.0076 mm (0.0003) inch). The coating thickness is chosen to ensure that the metal alloy coating is substantially free of pitting, as created by electrocoating, and does not shear when it is formed into products such as roofing materials, building materials, tangents gasoline, coatings or filter liners and / or various other products formed from strip metal. The thickness of the metal alloy coating preferably ranges from about .0254 - .0762 mm (0.001 to about 0.003 inch). The thickness of the coating is chosen to ensure that the metal alloy coating has essentially no pitting, such as is created by electrocoating, and does not shear when it is formed into products such as roofing materials, building materials, gasoline tangles, enclosures for filters and / or various other products that are formed from strip metal. The thickness of the metal alloy coating is preferably between about 0.2554 to about 0.7662 mm (about 0.001 to about 0.003 inch) 30.5 to 549 grams / m3 (0.1-1.8 ounce / ft2 @ density of 7,160 kg / m3 ( 447 pounds / foot3)). A coating thickness of at least about 0.025 inch (0.254 mm) forms a virtually pitless coating on the coating and resists tearing when the coating strip is stretched or formed, such as in gasoline tanking or roofing materials. These coating thicknesses essentially eliminate uncoated and unprotected areas on the strip surface commonly found in articles coated with thinner coatings. The coating thickness of at least about .0254 mm (0.001 inch) allows for greater elongation characteristics of the coated strip, as compared to the strip having a thin coating and results in the strip maintaining a protective coating across the surface of the strip. the strip during and after the metal strip has been stretched by a matrix. When coating rolls are used, protective material 78 is preferably located near the coating rollers 82. The protective material floats on the molten metal alloy 76, to prevent the molten alloy from solidifying and oxidizing, reducing foam formation and also aid in proper distribution of the metal alloy in the strip 12. When the coating rollers are employed, the protective material 78 is preferably located near the coating rollers 82. The protective material floats on the molten metal alloy 76. to prevent the molten alloy from solidifying and oxidizing, it reduces foaming and also assists in proper distribution of the metal alloy in the strip 12. In another alternate embodiment, Figure 3 illustrates a metal coating nozzle 84 which injects alloy of molten metal 76 on the outer surface of the coating roll 82. The cast alloy 76 applied by injection d The spray on the coating roller 82 is pressed against the strip 12 as the strip 12 travels between the coating roller 82 to fill any small surface areas on the strip 12 that have not been coated by the molten alloy in the melting vessel. Preferably, two coating injection nozzles are used. Still in another alternate modality, Figure 3a illustrates an air blade 100 which directs a gas with high velocity towards the metal alloy coating 76 on the strip 12. Two or more eroding nozzles 104, which are mutually opposite each other and disposed on the container of melt 70, direct high velocity gas 105 towards the coated strip 12 and down into the melting vessel 70, as the strip continuously travels between the eroding nozzles. The high velocity gas removes excess molten metal alloy from the strip, smears the molten alloy into the strip 12 to cover any pitting, reduces the thickness of the metal alloy coating on the strip and reduces lumps or ribs in the coating made of metal alloy. The high-velocity gas is preferably an inert gas so as not to induce oxidation of the molten metal alloy. The use of an inert gas also reduces foaming in the metal alloy coating and acts as a protective barrier to air, which causes viscous oxides to form on the surface of the molten metal alloy in the melting vessel. When using inert gas, the use of a protective material in the melting container is not regulated. Preferably, the inert gas is nitrogen or a heavier inert gas (higher density) than air. The eroding nozzles are preferably adjustable to direct the high velocity gas at various angles to the surface of the coated alloy to vary the amount of shaved coating of the strip. Although not illustrated, the eroding bogs are preferably circumscribed in a box-shaped sleeve containing the inert gas after the gas contacts the strip and recirculates the inert gas back through the eroding bogs.

When the air knife is employed, the air knife is preferably used as a substitute for or in conjunction with the coating rollers 82. After the strip 12 leaves the melting vessel 70 and the coating rollers 82 and / or blade of air 100, if employed, the strip coated with the metal alloy coating is cooled at least by a cooling water spray nozzle 92 as illustrated in Figure 4, as the strip 12 is guided by the guides of the camel back 90 as illustrated in Figure 6. The camel back guide 90 is designed such that it has two shrunken edges 92, formed by conical surfaces that contact only the edges of strip 12, to minimize the removal of metal alloy coating of the strip 12. The water 93 of the spray nozzle 92 is preferably maintained at ambient temperatures, but may be colder or warmer in temperature. The velocity of the water in the spray nozzle 92 is increased or decreased to vary the desired cooling rate of the molten metal alloy. In an alternate embodiment, as illustrated in Figure 2, the strip 12 is cooled in a cooling tank 94, where the strip 12 is immersed in cooling water 96. The cooling water 96 in the cooling tank 94, it is preferably kept at ambient temperatures and preferably stirred to increase the cooling rate of the tin coating. Rapid cooling of the alloy coating either by the cooling tank 94 or the cold water injection nozzle 92 is preferable, in order to produce an alloy coating having a fine grain size with increased grain density. Rapid cooling of the alloy coating also results in oxidation of the alloy coating surface, to produce a less reflective surface. The cooling time period preferably is less than about two minutes and more preferably about 10-30 seconds. As illustrated in Figure 1, once the strip has cooled, the strip is wound into the strip roller 150 for further processing and / or forming. In an alternate embodiment, the strip 12 is subjected to the leveler 100 as illustrated in Figure lb. The leveler 100 includes a number of level 102 rollers that produce a uniform and smooth metal alloy coating 142 on the strip 12. After the strip 12 leaves the leveler 100, the strip 12 is preferably cut by the shear 111 in the desired lengths of strip or embobina in strip roll 150.

In an alternate embodiment, the strip 12 is coated with a pre-weathering agent 112, as illustrated in Figure lb. The metal alloy coated strip 12 or the cutting blades 130 are pre-weather coated by pre-weathering applicators 114 which apply a pre-weathering agent 112. The pre-weathering agent 112 includes a base paint of asphalt that is applied to a thickness of approximately .0254 to .0508 mm (1 to 2 mils). Preferably, the coated sheets 130 or the metal strip 12 are coated with a pre-weathering agent 112 on both sides. The pre-weathering coating applicators 114 have applied the pre-weathering agent 112 either by the pre-weathering sprayer 116 and / or by rotary coating applicators 114 in the pre-weathering tank 110. The pre-weathering agent 112 -intellumination 112 is quickly dried by the thermal lamp 120 and / or by a dryer 122. The coated metal strip 12 or the cut sheets 130 are wound or wound on the roll of strip 150, stacked in sheets for transport or preformed in materials of roof, construction materials, gas tanks, filters, etc. In an alternate embodiment, Figure 9 illustrates a metal strip 12 unwound from the roll 10 and the strip proceeds directly to the melting vessel 70. The strip, upon leaving the melting vessel 70 passes through the coating rollers 82 and then through the air knife 100. After the strip 12 passes the air knife 100, the coated strip reembolls into the roller 150. This method is used for the metal strip such as carbon steel, tin, nickel alloys, titanium, bronze and copper. The stainless steel strip should preferably be pretreated and activated before coating. In another alternate embodiment, the strip coated with metal alloy proceeds from the melting vessel 70 or cooling tank 94, or the spray nozzles 92 in an oxidation tank, not shown. The oxidation tank preferably contains an oxidizing solution that removes the metal alloy coating from the strip 12 to expose the intermetallic layer 140, and exposes a corrosion-resistant barrier on the surface of the intermetallic layer. It has been found that the barrier is vastly superior in protecting against corrosion of a strip of stainless steel. The oxidant solution imparts color to the intermetallic layer 140. The oxidizing solution is preferably a nitric acid solution. The concentration of nitric acid is about 5% to 60% and preferably about 25%. By increasing the concentration of the nitric acid, the time required to remove the metal alloy coating 76 is shortened. The removal of the metal alloy coating is generally less than about two minutes. Preferably copper sulfate is added to the nitric acid, to further increase the removal rate of the alloy coating. Copper sulfate, when present, is added at a concentration of less than about 10% and preferably about 1% of the oxidizing solution. The temperature of the oxidant solution must be maintained at a temperature that provides sufficient activity. The temperature is maintained between about 30 to 80 ° C and preferably about 50 ° C. As the temperature of the oxidant solution increases, the activity of the oxidant solution increases, thus cutting the time required to remove the metal alloy coating from the strip 12. The oxidation tank preferably includes a stirrer to avoid stagnation and / or vast concentration differences of the oxidant solution in the tank and to prevent gas bubbles from forming on the surface of the strip 12. Once the metal alloy coating is removed, the exposed intermetallic layer is preferably passive to significantly improve the corrosion resistance of the intermetallic layer. The intermetallic layer is passivated by a passivation solution which preferably includes a solution containing nitrogen. Nitric acid is a type of passivation solution. When nitric acid is used, the removal of alloy coating and the intermetallic layer passivation both achieve in a single oxidation tank. Once the intermetallic layer is passive, the passivated layer is not removed by the oxidant solution, thus making the removal of the alloy coating and the passivation of the autocatalytic intermetallic layer. After strip 12 passes through the oxidation tank, strip 12 preferably proceeds to an oxidizing rinse tank, not shown. The rinse tank contains a liquid that removes any remaining oxidant solution from the strip 12. Preferably, the liquid is water at room temperature. The rinse tank preferably includes a stirrer to further assist in the removal of the oxidizing solution from the strip 12. The strip 12 is alternately rinsed off by the spray nozzles instead of a rinse tank. Once the rinsing process is complete, the strip is wound into the roll of strip 150, cut into sheets 130 or preform into various articles. In alternate form, the oxidant solution is applied subsequent to the preformed strip or sheets. For exampleWhen roofing materials of the strip or sheets are preformed, the roofing materials can be fully installed and welded together and the oxidizing solution can then be sprayed or applied onto the roofing materials to expose and oxidize the intermetallic layer. The general formulation of tin and zinc coating is as follows: Tin 15 - 90 Zinc 10 - 85 - Antimony 0.0 - 1.0 Bismuth 0.0 - 0.01 Silver 0.0 - 0.005 Copper 0.0 - 0.05 Iron 0.0 - 0.005 Aluminum 0.0 - 0.01 Arsenic 0.0 - 0.005 Cadmium 0.0 - 0.1 Nickel 0.0 - 0.005 Lead 0.0 - 0.1 A more specific formulation of the tin and zinc coating is as follows: Tin 70 - 90 Zinc 10 - 30 Antimony 0.001 - 0.8 Bismuth 0.001 - 0.005 Silver 0.0 - 0.005 Copper 0.001 - 0.02 Iron 0.0 - 0.005 Aluminum 0.001 - 0.01 Arsenic 0.0 - 0.005 Cadmium 0.0 - 0.01 Nickel 0.0 - 0.005 Lead 0.01 - 0.1 A very specific formulation of the tin and zinc coating is as follows: Zinc 18.5 - 20.5 Antimony 0.6 - 0.7 Bismuth 0.002 - 0.005 Silver 0.0 - 0.00 1 Copper 0.005 - 0.02 Iron 0.0 - 0.001 Aluminum 0.002 - 0.008 Arsenic 0.0 - 0.001 Cadmium 0.0 - 0.001 Nickel 0.0 - 0.001 Lead 0.02 - 0.08 Tin Rest A few examples of the composition of a Metal leaks that have exhibited the desired characteristics as mentioned above are stated as follows: Ingredients of Alloy A E Q D E Zinc 10 15 20 25 30 Copper < 0.5 < 0.5 < 0.5 < 0.5 < 0.5 Aluminum < 0.01 < 0.01 < 0.01 0.01 < 0.01 Lead < 0.1 < 0.1 < 0.1 < 0.1 < 0.1 Antimony < 1.0 < 1.0 < 1.0 < 1.0 < 1.0 Bismuth < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 Iron < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 Silver < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 Arsenic < 0.005 < 0.005 < 0.005 < 0.005 < 0.005 Cadmium < 0.01 < 0.01 < 0.01 < 0.01 < 0.01 Nickel < 0.005 < 0 005 < 0 005 < 0 005 < 0 005 Tin Remainder Remainder Remainder Remainder Typically, formulations of metallic tin and zinc coatings include: 10-40% zinc; 60-90% tin; 0.0-0.4% magnesium; 0.0-0.1% manganese; 0.0-1.0% nickel; 0.0-2.0% copper; 0.0-0.15% titanium; 0.0-0.5% aluminum; 0.0-2.0 antimony; 0.0-1.5% bismuth; up to 1.0% iron, 0.0-0.5% silicon, 0.0-0.1% cadmium, 0.0-0.05% boron, 0.0-0.5% carbon, 0.0-0.5% chromium, 0.0-0.1% molybdenum, 0.0- 0.1% vanadium, 0.0-0.01% silver, 0.0-0.01% arsenic, 0.0-0.01% sulfur, 0.0-0.01% tellurium and less than 0.5% lead. Preferably, the tin-zinc coating formulations are 10-30% zinc; 70-90% tin; 0.0-0.1% magnesium; 0.0-0.1% manganese; 0.0-0.5% nickel; 0.0-0.5% copper; 0.0-0.05% titanium; 0.0-0.1% aluminum; 0.0-0.01% cadmium, 0.0-0.05% silver, 0.0-0.05% arsenic, 0.0-1.0% bismuth and / or antimony; less than 0.05% iron; less than 0.1% lead; and the content of tin plus zinc which is at least 95% of the coating. Preferably, the tin-zinc coating formulations are 15-25% zinc; 75-85% tin; 0.0-0.001% magnesium; 0.0-0.001% manganese; 0.0-0.001% nickel; 0.005-0.02% copper; 0.00-0.001% titanium; 0.001-0.01% aluminum; 0.001-0.8% antimony and / or bismuth; 0.0-0.001% iron; 0.01-0.08% lead; 0.0-0.001% cadmium, 0.0-0.005% arsenic, 0.0-0.01% silver and the content of tin plus zinc is at least 98%, preferably 99% of the coating. EXAMPLE A A carbon steel strip is unwound from a steel strip roll to carbon. The carbon steel strip has a thickness of less than approximately .762 mm (0.03 inch). The strip is continuously passed through an electrolytic tank to coat nickel on the surface of the strip. The nickel-coated layer has a thickness of about 1-3 microns. The metal alloy includes at least about 95% tin and zinc and less than about 0.5% lead. The metal is in a melting vessel at a temperature of about 302 to 454 ° C (575 to 850 ° F). The strip is passed through the fire vessel which has an approximate length of 4.9 m (16 feet) at a rate of approximately 30.5 m / minute (100 feet / minute) and has a residence time in the melting vessel lower than approximately 10 seconds. The coated strip is passed through coating rollers and / or an air knife to achieve a coating thickness of approximately .00762 to .0762 mm (0.0003 to 0.003 inch). The coated strip is rewound on a roll of the coated strip. EXAMPLE B A carbon steel strip is unwound from a strip of steel strip to coal. The carbon steel strip has a thickness of less than approximately .0762 mm (0.03 inch). The carbon steel strip is coated with chrome of a thickness less than about 3 microns. The metal alloy is at least about 98% tin and zinc and less than 1.0% of a metal additive and less than about 0.1% lead. The metal alloy is heated in a melting vessel at a temperature of about 302 to 482 ° C (575-900 ° F). The strip is passed through the melting vessel with an approximate length of 4.9 m (16 feet) at a rate of about 30.5 m / minute (100 feet / minute) and has a residence time in the melting vessel of less than about 10 seconds. The coated strip is passed through coating rollers and / or an air knife, to achieve a coating thickness of approximately .00762 to .0762 mm (0.0003 to 0.003 inch). The coated strip is rewound in a coated strip roller. EXAMPLE C A copper strip is unwound from a copper strip roller. The copper strip has a thickness less than approximately .0762 m (0.03 inch). The copper strip is coated continuously with a layer of tin of 1-3 microns thick. The metal alloy is at least about 99% tin and zinc. The metal alloy is heated in a melting vessel at a temperature of about 302 to 482 ° C (575-900 ° F). The strip is passed through the melting vessel which is approximately 4.9 m (16 feet) long at a rate of about 3.5 m / minute (100 feet / minute) and has a residence time in the melting vessel, lower to approximately 10 seconds. The coated strip is passed through coating rollers and / or an air knife to achieve a coating thickness of about 0.00762 to 0.762 mm (0.0003-0.003 inch).

The coated strip is rewound in a roll of coated strip. EXAMPLE D A carbon steel strip is unwound from a roll of carbon steel strip and continuously coated with a tin layer of a thickness less than about 3 microns. The carbon steel strip has a thickness less than .0762 mm (0.03 inch). The metal alloy is at least about 98% tin and zinc and less than 0.1% lead. The metal alloy is heated in a melting vessel at an approximate temperature of 302 to 427 ° C (575-800 ° F). The strip is passed through the melting vessel having an approximate length of 4. 9 m (16 ft.), At a speed of approximately 30.5 m / minute (100 ft./min.) And has a residence time in the fire vessel of less than about 10 seconds. The coated strip is passed through coating rollers and / or an air knife, to achieve a coating thickness of approximately .00762 to .0762 mm (0.0003- 0.003 inch). The coated strip is rewound in a roll. EXAMPLE E A stainless steel strip is unwound from a stainless steel strip roller. The stainless steel strip is continuously coated with a thin layer of approximately 1-3 microns thickness. The stainless steel strip has a thickness less than .0762 mm (0.03 inch). The metal alloy is at least about 98-99% tin and zinc and is heated in a melting vessel at a temperature of about 302 to 427 ° C (575-800 ° F). The strip is passed through the melting vessel having a length of about 4.9 m (16 feet) at a rate of about 30.5 m / minute (100 feet / minute) and has a residence time in the melting vessel, lower to approximately 10 seconds. The coated strip is passed through coating rollers and / or an air knife, to achieve a coating thickness of approximately 0.0076 to 0.762 mm (0.0003-0.003 inch). The coated strip is rewound in a roll. EXAMPLE F A carbon steel strip is unwound from a roll and etched with a solution of hydrochloric acid and a solution of copper sulfate. The copper is coated on the surface of the strip during pickling, to form a copper layer with an approximate thickness of 1-3 microns. The carbon steel strip has a thickness less than .0762 mm (0.03 inch). The metal alloy includes at least about 95-99% tin and zinc and less than 0.2% lead. The metal is in a melting vessel at a temperature of approximately 302 to 482 ° C (575-900 ° F). The strip is passed through the melting vessel having a length of about 4.9 m (16 ft), at a rate of about 30.5 m / minute (100 ft / minute) and has a residence time in the lower fired vessel to approximately 10 seconds. The coated strip is passed through coating rollers and / or an air knife, to achieve a coating thickness of approximately .00762 to .0762 mm (0.0003-0.003 inch). The coated strip is rewound in a roll. The thickness of the alloy of two tin and zinc faeces is varied depending on the environment in which the treated roofing system is used. The two-phase alloy exhibits superior corrosion-resistant properties in rural, industrial and marine environments. The metal alloy coating is preferably applied in a thickness between about 0.00254 to 1.27 mm (0.0001-0.05 inch). Preferably, the thickness of the metal alloy coating is at least about 0.0003 inch and preferably about 0.0025-0.003 inch. This thickness of metal alloy coating has been found to be suitable for avoiding and / or significantly reducing corrosion of the metal strip in virtually all types of environment.

Metal alloy coatings that have thicknesses greater than .00762 mm (0.003 inch), can be used in harsh environments to provide additional protection against corrosion. The metal alloy is designed for use in all types of coated metal applications. The coated metal can be used to support press fit and seam (mechanical bonding, as illustrated in US Patent No. 4,987,716) for roofing. In sewing applications, the edges of the roofing materials are folded together and then welded together to form a watertight seal. The metal alloy inherently includes excellent welding characteristics. When the metal alloy is heated, it has the necessary wetting properties to produce a water-tight, resistant seal. As a result, the metal alloy acts both as a corrosion resistant coating and as a welding agent for supporting roof systems seam. The coated metal alloy can also be welded with standard welds. Typical solders contain approximately 50% tin and approximately 50% lead. The metal alloy has the added advantage of also being able to bond with low lead or low lead solder joints. Roofing materials coated with metal alloy can also be used to mechanically bond roof systems due to the malleability of the metal alloy. Mechanically bonded systems for water-impermeable seals by folding edges of roofing material adjacent to each other and subsequently applying a compression force to the seam that exceeds approximately 70.3 kg / cm2 (approximately 1000 psi). Under these high pressures, the metal alloy deforms plastically within the seam and produces a watertight seal. The invention has been described with reference to preferred and alternative embodiments. Modifications and alterations will be apparent to those with skill in the art upon reading and understanding the detailed discussion of the invention herein provided. This invention is intended to include all these modifications and alterations as long as they fall within the scope of the present invention.

Claims (51)

1. CLAIMS 1. A strip of metal coated with a corrosion resistant tin and zinc alloy, which is applied to the surface of the metal strip, the coating is characterized in that it contains at least about 15 weight percent tin, at least about 10 weight percent zinc and one metal additive, the tin plus zinc constitute at least about 90 weight percent of the alloy, the metal additive includes a metal selected from the group consisting of lead, antimony, bismuth , copper, aluminum, cadmium and their mixtures.
2. 2. A metal strip according to claim 1, characterized in that the tin content plus the zinc content is at least about 98 weight percent of the alloy.
3. 3. A metal strip according to claim 2, characterized in that the content of tin plus the zinc content is at least about 99 weight percent of the alloy.
4. 4. A metal belt according to claims 1-3, characterized in that the zinc content is about 10 percent to about 85 percent by weight of the alloy.
5. 5. A metal strip according to claim 4, characterized in that the zinc content is about 15 percent to about 40 percent by weight of the alloy.
6. 6. A metal strip according to claims 1-5, characterized in that the metal additive includes lead, the lead content is about 0.001 to about 0.1 weight percent.
7. 7. A metal strip according to claims 1-6, characterized in that the metal additive is selected from the group consisting of at least an effective amount of a stabilizing agent for inhibiting tin crystallization, at least an effective amount of a corrosion-resistant agent to improve the corrosion-resistant properties of the alloy, at least an effective amount of a coloring agent to alter the color of the alloy, at least an effective amount of a reflecting agent to alter the reflectivity of the alloy, to the less an effective amount of a grain agent to alter the grain density of the alloy, at least an effective amount of a mechanical agent to alter the mechanical properties of the alloy, at least an effective amount of deoxidizing agent to reduce the amount of oxidation of the alloy in a molten state, at least an effective amount of the binding agent to improve the properties of the alloy and its mixtures. A metal strip according to claim 7, characterized in that the corrosion resistant agent includes a metal selected from the group consisting of antimony, bismuth, cadmium, chromium, copper, lead, manganese, magnesium, nitrile, titanium and its mixtures 9. A metal strip according to claims 7-8, characterized in that the coloring agent includes a metal selected from the group consisting of copper, lead, titanium, iron, silver, cadmium and their mixtures. 10. A metal strip according to claims 7-9, characterized in that the reflective agent includes a metal selected from the group consisting of aluminum, chromium, copper, cadmium, silver, titanium and mixtures thereof. 11. A metal strip according to claims 7-10, characterized in that the grain agent includes a metal selected from the group consisting of manganese, cadmium, titanium and mixtures thereof. 12. A strip of metal according to claims 7-n, characterized by the mechanical agent includes a metal selected from the group consisting of antimony, aluminum, manganese, bismuth, chromium, copper, iron, nitrile, silver, cadmium, arsenic , lead, magnesium, titanium and their mixtures. 13. A metal strip according to claims 7-12, characterized in that the deoxidizing agent includes a metal selected from the group consisting of aluminum, magnesium, manganese, cadmium, titanium and their mixtures. 14. A metal strip according to claims 7-13, characterized in that the binding agent includes a metal selected from the group consisting of lead, titanium, manganese, cadmium and mixtures thereof. 15. A metal strip according to claims 1-14, characterized by the alloy comprising: Tin 15-90 Zinc 10.85 Antimony 0.0-1.0 Bismuth 0.0-0.01 Silver 0.0-0.005 Copper 0.0-0.05 Iron 0.0-0.005 Aluminum 0.0- 0.01 Arsenic 0.0-0.005 Cadmium 0.0-0.005 Nickel 0.0-0.005 Lead 0.0-0.1 16. A strip of metal according to claim 15, the alloy comprises: Tin 40-85 Zinc 15-60 Antimony 0.001-0.8 Bismuth 0.001-0.005 Silver 0.0-0.005 copper 0.001-0.02 Iron 0.0-0.005 Aluminum 0.001-0.01 Arsenic 0.0-0.005 Cadmium 0.0-0.005 Nickel 0.0-0.005 Lead 0.01-0.1 17. A metal strip according to claims 1-16, characterized in that the The coating on the base metal has a thickness of about .00254 to about 2.54 mm (0.0001 to about 0.1 inch). 18. A metal strip according to claims 1-17, characterized in that it includes an intermediate metal layer placed between the base metal surface and the alloy coating. 19. The metal strip according to claim 18, characterized in that the thickness of the intermediate metal layer is approximately 1 to 3 microns. 20. The metal strip according to claims 18-19, characterized in that the intermediate metal layer is selected from the group consisting of chromium, copper, nickel, tin and their mixtures. 21. The metal strip according to claims 1-20, characterized in that the base metal is stainless steel, carbon steel, copper or bronze. The metal strip according to claims 1-21, characterized in that the alloy is coated on the surface of the strip by a process selected from the group consisting of electrocoating, electrocoating and subsequent flow heating, coating by hot dip, air blade application and metal spraying. 23. The metal strip according to claim 22, characterized in that the alloy is heated during the coating of the strip to form an intermetallic layer between the surface of the strip and the alloy, the heating of the alloy is by a selected method of the group consisting of electro-coating and subsequent flow heating, hot dip coating, air knife application and metal spraying. 24. The metal strip according to claim 23, characterized in that the intermetallic layer has a thickness of 1-10 microns. 25. A method for producing a corrosion-resistant base metal, characterized in that it comprises the steps of: (a) providing a base metal sheet; Y (b) applying an alloy of tin and zinc metals on the base metal surface, to form a coating on the base metal, the metal alloy includes at least 15 weight percent tin and at least 10 weight percent zinc and a metal additive, the tin content plus the zinc content constitutes at least about 90 weight percent of the alloy, and the metal additive includes a metal selected from the group consisting of lead, antimony, bismuth, cadmium , copper, aluminum and their mixtures. 26. The method according to claim 25, characterized in that it includes the step of heating the alloy on the base metal surface to form an intermetallic layer between the base metal surface and the alloy. The method according to claim 26, characterized in that the step of heating includes the application of the alloy on the surface of the base metal by a process selected from the group consisting of electrocoating and subsequent flow heating, dip coating. hot, application of air knife and metal spray. 28. The method according to claims 25-27, characterized in that it includes the step of applying a layer of intermediate metal to the surface of the base metal before applying the alloy. 29. The method according to claims 25-28, characterized in that the tin content plus the zinc content is at least about 98 weight percent of the alloy. 30. The method according to claims 25-29, characterized in that the tin content plus the zinc content is at least about 99 weight percent of the alloy. 31. The method according to claims 25-30, characterized in that the zinc content is about 10 to about 40 weight percent of the alloy. 32. The method according to claims 25-31, characterized in that the metal additive includes lead, the content of lead is about 0.001 to about 0.1 weight percent. The method according to claims 25-32, characterized in that the metal additive is selected from the group consisting of at least an effective amount of a stabilizing agent to inhibit tin crystallization., at least an effective amount of a corrosion resistant agent to improve the corrosion resistance properties of the alloy, at least an effective amount of a coloring agent to alter the color of the alloy, at least an effective amount of a reflecting agent to alter the reflectivity of the alloy, at least an effective amount of a grain agent to alter the grain density of the alloy, at least an effective amount of a mechanical agent to alter the mechanical properties of the alloy, at least an amount effective of deoxidizing agent to reduce the amount of oxidation of the alloy in a molten state, at least an effective amount of binding agent to improve the bonding properties of the alloy and its mixtures. 34. The method according to claim 33, characterized in that the stabilizing agent includes a metal selected from the group consisting of antimony, bismuth, cadmium, copper and their mixtures. 35. The method according to claims 33-34, characterized in that the corrosion resistant agent includes a metal selected from the group consisting of antimony, bismuth, cadmium, chromium, copper, lead, manganese, magnesium, nickel, titanium and its mixtures 36. The method according to claims 33-35, characterized in that the coloring agent includes a metal selected from the group consisting of copper, lead, titanium, silver, iron, cadmium and their mixtures. 37. The method according to claims 33-36, characterized in that the reflective agent includes a metal selected from the group consisting of aluminum, cadmium, chromium, copper, silver, titanium and their mixtures. 38. The method according to claims 33-37, characterized in that the grain agent includes a metal selected from the group consisting of manganese, cadmium, titanium and mixtures thereof. 39. The method according to claims 33-38, characterized in that the mechanical agent includes a metal selected from the group consisting of antimony, aluminum, manganese, bismuth, copper, iron, chromium, magnesium, nickel, silver, cadmium, arsenic. , lead, titanium and their mixtures. 40. The method according to claims 33-39, characterized in that the deoxidizing agent includes a metal selected from the group consisting of aluminum, magnesium, manganese, cadmium, titanium and mixtures thereof. 41. The method according to claims 33-40, characterized in that the binding agent includes a metal selected from the group consisting of lead, titanium, manganese, cadmium and their mixtures. 42. The method as defined in claims 25-41, characterized in that the alloy comprises: Tin 15-90 Zinc 10-85 Antimony 0.0-1.0 Bismuth 0.0-0.01 Silver 0.0-0.005 Copper 0.0-0.05 Iron 0.0-0.005 Aluminum 0.0- 0.01 Arsenic 0.0-0.005 Cadmium 0.0-0.005 Nickel 0.0-0.005 Lead 0.0-Ol 43. The method according to claims 25-42, characterized in that the alloy comprises: Tin 40-85 Zinc 15-60 Antimony 0.001-0.8 Bismuth 0.001 -0.005 Silver 0.0-0.005 Copper 0.001-0.02 Iron 0.0-0.005 Aluminum 0.001-0.01 Arsenic 0.0-0.005 Cadmium 0.0-0.005 Nickel 0.0-0.005 Lead 0.01-0.1 44. The method according to claims 25-43, characterized in that the The coating on the base metal has a thickness of about .00254 to about 2.54 mm (about 0.0001 to about 0.1 inch). 45. The method according to claims 28-44, characterized in that the thickness of the intermediate metal layer is approximately 1 to 3 microns. 46. The method according to claims 28-45, characterized in that the intermediate metal layer is selected from the group consisting of chromium, copper, nickel, tin, and mixtures thereof. 47. The method according to claims 25-46, characterized in that the base metal is stainless steel is carbon steel, copper or bronze. 48. The method according to claims 26-47, characterized in that the intermetallic layer has a thickness of 1-10 microns. 49. A copper strip coated with a corrosion resistant tin and zinc alloy applied to the surface of the copper strip, the coating comprises at least about 15 weight percent tin and at least about 10 weight percent zinc and a metal additive. 50. A copper strip as described in claim 49, characterized in that the alloy comprises: Tin 15-90 Zinc 10-85 Antimony 0.0-1.0 Bismuth 0.0-0.01 Silver 0.0-0.005 Copper 0.0 -0.05 Iron 0.0-005 Aluminum 0.0 -0.01 Arsenic 0.0-0.005 Cadmium 0.0-0.005 Nickel 0.0-0.005 Lead 0.0-0.1 51. A copper strip as described in claim 50, characterized in that the alloy comprises: Tin 40-85 Zinc 15-60 Antimony 0.001-0.
8. 8 Bismuth 0.001-0.005 Silver 0.0-0.005 Copper 0.001-0.02 Iron 0.0-0.005 Aluminum 0.001-0.01 Arsenic 0.0-0.005 Cadmium 0.0-0.005 Nickel 0.0-0.005 Lead 0.01-O. 1 RfiSUMBN PB IA IWVBWCIQ - T A corrosion-resistant coated base metal, coated with an alloy of tin and zinc, where the tin content plus zinc content makes up a majority of the alloy. The coating alloy may also include one or more metal additives to improve the coating process and / or alter the properties of the tin and zinc alloy. A metal layer can also be applied to the surface of the base metal before applying the metal alloy coating. E8 / bo + frp / 27 / F9-1779