KR20120054239A - Coating material for preventing corrosion and manufacturing method thereof - Google Patents

Abstract

PURPOSE: An anti-corrosive and environmentally-friendly surface coating material for metal and a manufacturing method thereof are provided to prevent the corrosion of base metal by isolating the base metal from external pollutants. CONSTITUTION: An anti-corrosive and environmentally-friendly surface coating material for metal comprises aluminium powder of 5-30wt.%, alumina powder of 50-70wt.%, NH4Cl(Ammonium Chloride) of 1-5wt.%, zinc of 1-5wt.%, copper of 1-5wt.%, magnesium of 1-5wt.%, and titanium of 1-5wt.%. The coating material is spread on base metal and heated to 840-1,300°C or 840-1,000°C.

Description

Surface coating material for metal corrosion and its manufacturing method for environment-friendly pollution prevention and ultra-weather resistance neutralization prevention {Coating material for preventing corrosion and manufacturing method

The present invention relates to a surface coating material for preventing the corrosion of metals and a method of manufacturing the same.

The present invention is applicable to all metals used in automobiles and ships, and all products and parts related thereto and metal products necessary for daily life.

The problems associated with metals that cannot be considered in all fields including construction can be said to reduce the durability of metals such as corrosion and scaling and shorten their lifespan.

Anticorrosive coatings of steel are already known in the art, for example by depositing metal coatings with aluminum or aluminum alloys, or zinc or zinc alloys by hot dip or electroplating processes.

Particularly used in the automotive industry, bearing steel parts are often made of high strength heat-treated steel. This involves the steel being annealed at temperatures higher than 800 ° C to 900 ° C and hot formed, and then cooled again to a sufficiently high cooling rate to produce a high strength martensitic microstructure. It is important to convert the to austenitic form.

When cooling and hardening are carried out in a forming tool, the use of press hardening allows for the preparation of high strength components. The pre-drawn portions are preformed at room temperature (cold forming). The problem encountered during hot forming after cold forming is the scaling that occurs on the steel surface, where the scale layer, which appears as a metal oxide by direct reaction with atmospheric oxygen at high temperatures, is hard and brittle, especially during cooling. Is sliced into chunk-like pieces. This scale layer damages both components and the forming tool and must be cleaned after each forming step to remove the scale flakes.

The EP 1 013 785 A1 application describes the coating of a hot rolled sheet with a metal or metal alloy. The coating is applied by hot dip coating (hot dip aluminum aluminizing) to form a layer of aluminum or an alloy of aluminum, iron and silicon. This kind of protective layer allows effective protection against the scale during the heating to austenitizing temperature but has limitations when used in performing press hardening operations.

In DE 102 46 614 A1, during the hot dip process described in EP 1 013 785 A1, an intermetallic alloy phase can be formed between steel and the actual coating already formed during the coating process, which is hard and brittle. It is described as cracking during cold deformation. The fine cracks formed cause the coating to flake off from the original material and lose its protective action. It is therefore evident that the hot dip aluminum treatment is not suitable for cold forming, nor will it be suitable for two-stage cooling and hot forming processes. DE 102 46 614 A1 suggests that this problem can be overcome by applying a protective metal coating by means of depositing a layer of aluminum or an aluminum alloy, or a layer of zinc or zinc alloy using the electroplating method. However, electrodeposition of aluminum to steel is time consuming and expensive and is very unreasonable. Also, if zinc and zinc alloys are used instead, hot forming applications are also extremely limited because most of the zinc is oxidized upon heating or evaporated if a protective gas is used.

While the above is directed to problems associated with steel, which is often used in the automotive industry, most metals are susceptible to corrosion, particularly atmospheric corrosion, and as a result, various kinds of rust are formed. Such corrosion can greatly affect the quality of the metal. Surface corrosion can usually be removed from the metal surface, but the processes for its removal tend to be time consuming, costly, and have a negative impact on the integrity of the metal. If the coating is applied to a metal surface, corrosion of the metal may result in insufficient or ineffective adhesion between the coating and the metal surface. It may cause a decrease in adhesion between the coating and the metal surface to which it is applied or corrosion of the metal.

It is well known that preventing rust from forming in metals during storage, shipping and use of metals can be achieved by applying a thin film, such as chromate, to the surface of the metal. Although providing resistance to formation, chromium is very toxic and environmentally undesirable. In addition, the chromium layer does not help to improve the adhesion of the other layer applied.

The present invention is made to improve the problems associated with the coating material for preventing the conventional metal corrosion, the object of the present invention is to effectively prevent the corrosion of the base material to improve the adhesion and at the same time effectively isolate the base material and external contaminants to be adhered thereto. It is to provide a surface coating material and a method of manufacturing the same.

In order to achieve the above object, the surface coating material for preventing corrosion of the metal of the present invention and a method of manufacturing the same, in the coating material for protecting the metal from corrosion, having a resistance to oxidation process when reducing conditions are formed in the coating It is characterized by consisting of aluminum, alumina, zinc, magnesium, graphite, copper and titanium as the electrically conductive component.

The present invention is 5 to 30% by weight of aluminum powder, 50 to 70% by weight of alumina powder, 1 to 5% by weight of NH ₄ Cl, 1 to 5% by weight of zinc, 1 to 5% by weight of copper, 1 to 5% by weight of magnesium, titanium It is characterized by consisting of 1 to 5% by weight.

The coating material of the present invention is characterized in that it is heated to a temperature of 840 ℃ ~ 1,300 ℃, preferably 840 ℃ ~ 1,000 ℃ after being applied to the base material.

The coating material of the invention is characterized by containing 5 to 95% by weight, preferably 10 to 75% by weight of binder and 0 to 90% by weight, preferably 25 to 75% by weight of pigments and / or fillers. .

According to the surface coating material for preventing the corrosion of the metal of the present invention and a method of manufacturing the same, to isolate the base material and the external contaminants adhering to each other to prevent corrosion of the base material to improve the strength of the base material and high temperature resistance, chemical resistance, corrosion resistance and There is an advantage that a metal having excellent waterproofness can be provided.

In addition, according to the surface coating material for preventing the corrosion of the metal according to the present invention and a method of manufacturing the same, by improving the adhesion of the base material and the coating material adhered to it to isolate the base material and the material to be adhered to each other to prevent corrosion of the base material and at the same time By preventing the crack, there is an advantage in that the strength of the base material and the metal having excellent high temperature resistance, chemical resistance, corrosion resistance, and water resistance can be provided.

Hereinafter, embodiments of the present invention will be described in detail.

When metal is changed into oxide or other compound under the influence of moisture, oxygen or carbon dioxide in air, it is called metal corrosion.

Iron rusts gradually as well as its surface in humid air. Therefore, iron does not rust in the place where there is no water at all, even in the absence of oxygen at all, so the surface of the oil or paint should be blocked the contact of water or oxygen. Coating steel plates on automobiles and ships prevents rust. Metal surfaces can also be plated to prevent corrosion.

For example, aluminum bowls or aluminum chassis windows can be artificially coated with oxides (anodized) to prevent corrosion of aluminum. The surface of iron is made of black ferric tetraoxide Fe ₃ O ₄ to protect the inside. Oxidation of iron is promoted by oxygen, salt, etc. dissolved in water. Indeed, near the ocean, the corrosion of metals is high due to the effects of seawater. In addition, oxides of nitrogen and sulfur are contained in the air, in addition to oxygen, so that they adhere on the surface of iron and react with water to cause rust.

The surface coating material of the metal material according to the present invention for preventing corrosion of such metals is 5 to 30% by weight of aluminum powder, 50 to 70% by weight of alumina powder, 1 to 5% by weight of NH ₄ Cl, 1 to 5% by weight of zinc. , 1 to 5% by weight of copper, 1 to 5% by weight of magnesium, 1 to 5% by weight of titanium.

Among the components, aluminum powder, zinc, copper, and magnesium are vaporized when heated to a temperature of 660 ° C. or higher, which is the melting point temperature of aluminum, and thus requires a coating material.

Diffuses and penetrates the surface.

The alumina powder is added for the purpose of sintering, tangling, fusion prevention, etc. when heated to a high temperature.

The NH ₄ Cl reacts with the aluminum, zinc, stocks, copper and magnesium in the vapor state to serve to activate diffusion and penetration.

The zinc is formulated to prevent corrosion of metals in water and to be used for electrical applications.

The copper is combined with the aluminum to increase the hardness and tensile strength of the metal.

Since magnesium is a pure metal has a low structural strength, the magnesium is combined with aluminum and zinc to increase the hardness, tensile strength and corrosion resistance of the metal.

Titanium is a light, hard and corrosion-resistant transition metal element with silver-white metallic luster, which has excellent corrosion resistance and low specific gravity, resulting in only 60% of the weight of steel. It is formulated to have waterproof and corrosion resistance.

The coating method according to the present invention is as follows.

The base material on which the coating layer should be formed and the coating material blended with the above composition are put together in a closed furnace and argon gas is injected into the closed furnace at a rate of 2 L / min to prevent oxidation of the base material. It is maintained for 4 to 6 hours at a temperature of 850 to 950 ℃ in the state.

By performing the above steps, aluminum powder, alumina powder, zinc, copper, magnesium, and titanium in a vapor state are formed inside the closure, and the aluminum powder, alumina powder, zinc, copper, magnesium, and titanium blend penetrate the surface of the base material to coat the coating layer. Is formed.

After the coating layer is formed, the internal temperature of the coating material / substrate composite is maintained at a temperature of 840 ° C to 1,300 ° C, preferably 840 ° C to 1,000 ° C, for 12 to 48 hours to form a coating layer for preventing corrosion on the surface of the base material. As a result, the surface of the base material and the outside air are isolated.

At this time, in performing the process, the sudden temperature change may change the temperature at a rate of 50 ° C./hr since the coating layer on the surface of the base material may be peeled off.

The coating of the present invention also provides the following advantages. The present coating has a very wide range of uses and can be applied by various methods such as curtain coating, spray painting, dip coating, flooding and the like.

The coatings of the present invention can be applied in very thin layer thicknesses in addition to the principle protection against corrosion and / or scale, thereby improving electrical conductivity as well as saving material and cost. A thin electroconductive primer may be applied on top of the coating if high electrical conductivity is desired even after the hot forming process.

After the forming process or the hot forming process, the coating material may be retained on the surface of the substrate, for example, to increase scratch resistance, to improve corrosion protection, to meet aesthetic appearance, to prevent discoloration, and to be electrically conductive. And can be provided as a primer for conventional downstream processes (eg dip and electrophoretic dip coating).

It is within the scope of the present invention when the coating material contains 5 to 95% by weight of binder and preferably 10 to 75% by weight of binder and 0 to 90% by weight of pigment and / or filler of 25 to 75% by weight. to be.

It is also advantageous for the coating material to contain metal pigments, in particular iron, silver or other rare metals or metal salts.

These components improve corrosion protection and prevent high temperature corrosion forming scales.

Metal substrates are suitable for steel, steel alloys or steel provided with a metal coating, in particular of these metals such as aluminum, zinc, magnesium, tin or aluminum-silicon, aluminum-iron, zinc-iron, zinc-silicon and zinc-aluminum-silicon It is within the scope of the present invention to be the provided steel of the metal coating of the alloy.

Claims (5)

In coating materials for protecting metals from corrosion and / or scale,
A surface coating material for preventing corrosion of a metal, characterized in that a mixture of aluminum, alumina, zinc, magnesium, copper, and titanium, which contains a part of an electrically conductive component that is resistant to an oxidation process when reducing conditions are formed in the coating. According to claim 1, wherein the aluminum powder 5-30% by weight, alumina powder 50-70% by weight, NH ₄ Cl 1-5% by weight, zinc 1-5% by weight, copper 1-5% by weight, magnesium 1-5 Surface coating material for preventing corrosion of metal, characterized in that consisting of 1% by weight to 5% by weight of titanium. The method of claim 1 or 2, wherein the coating material is heated to a temperature of 840 ° C-1,300 ° C, preferably 840 ° C-1,000 ° C after being applied to the metal base material. Surface coating material. The method of claim 1, wherein the coating material contains 5 to 95% by weight, preferably 10 to 75% by weight of binder and 0 to 90% by weight, preferably 25 to 75% by weight of pigments and / or fillers. Surface coating material for preventing corrosion of metal. A metal base material coated with a surface coating material for preventing corrosion of the metal according to claim 1.