JP4668826B2 - Cold drawing method for metal and method for producing drawn material - Google Patents

Description

  The present invention relates to a method for cold drawing metal such as a metal tube, wire or bar, and a method for producing a drawn material such as the metal tube, wire or wire. In more detail, a lubricating film having high lubricity is formed on a workpiece to be processed for drawing, thereby reducing friction, for example, a tool by reducing processing power or suppressing wear and seizure. The present invention relates to a method for cold-drawing a metal and a method for producing a drawn material, which can extend the life of the metal and improve product quality.

  In general, cold drawing of metal tubes, metal wires or metal bars uses liquid or solid lubricants to reduce friction caused by metal contact between the material and the tool and to prevent seizure and galling. Yes. Lubricants used for cold drawing are usually selected according to the work material and tool material, processing method, surface pressure, processing speed, surface roughness, working environment, etc. There are types. One is a lubricant that physically adheres to the metal surface, and the other is a lubricant that adheres a lubricant after a carrier film is formed on the metal surface by a chemical reaction.

  As the lubricant to be physically adhered, for example, a mineral oil, vegetable oil or synthetic oil as a base oil to which an extreme pressure agent is added, which is directly attached to the surface of the material and then subjected to a drawing process can be exemplified. In addition, a solid lubricant such as metal soap, graphite or molybdenum disulfide is dispersed in water together with a binder component, and after being attached to the surface of the work material, it is dried and then drawn. . These lubricants have the advantage that a lubricating coating can be formed by coating or dipping, and there is almost no need for liquid management.

  On the other hand, the treatment with a lubricant formed by a chemical reaction is a so-called chemical film treatment. After a chemical reaction forms a film such as a phosphate having a role as a carrier on the material surface, stearin is used as a lubricant. A treatment with a reactive soap such as sodium sulfate or calcium stearate or a non-reacted soap is performed. This type of lubricant has a two-layer structure of a conversion coating as a carrier and a lubricant, and exhibits high seizure resistance. Therefore, it has been used as a lubricant in a very wide range in the plastic processing field such as wire drawing, pipe drawing, and forging.

  However, since the chemical conversion film treatment is a chemical reaction, it is difficult to treat a substance having poor chemical reactivity, and complicated liquid management is required even for those that can be treated. In addition, since a lubricant is applied on the chemical conversion film to be formed, a large number of processing steps are required including water washing and pickling. In addition, since a large amount of waste liquid comes out from the washing water and chemical conversion coating used in the treatment and heating is necessary to control the chemical reaction, capital investment and operation are expensive.

  In order to solve the above problems, for example, Patent Document 1 discloses a plastic working lubricant that forms a water-soluble resin film, and protects the surface of a work material represented by a thin steel plate and performs press forming. It can be used for press molding to improve lubricity. Patent Document 2 discloses that an aqueous solution or an organic solvent solution of polyether polyester or polyether polyurethane containing a polyether portion derived from ethylene oxide is used for processing metal pipes, wires, plates and the like.

JP 47-39965 A Japanese Patent Laid-Open No. 3-231995

  However, in the lubricant described in Patent Document 1, it is normal to separately use a lubricating oil that also serves as rust prevention during press molding. Originally, such a water-soluble resin film itself is necessary during plastic processing. Sufficient lubricity could not be found. Further, in the lubricant described in Patent Document 2, since the adhesion between the metal and the lubricating film is not sufficient, when the load is high or when metal processing that tends to cause seizure is plastically processed, the lubricity There was a shortage. Furthermore, in the case of a metal tube or bar wire, a general dipping method causes liquid sag, the upper part becomes a thin film and tends to be seized, and the lower part becomes too thick, resulting in poor drying or poor drying. There was a problem that seizure or the like was likely to occur.

  Accordingly, the present invention provides a cold drawing method and a drawing method capable of forming a lubricating film having high lubricity that does not require a base by chemical conversion treatment and improving the drawing processability of a material on which the lubricating film is formed. It is an object to provide a method for manufacturing a material.

  As a result of intensive studies, the present inventors have obtained the following knowledge and the like in order to solve the above-described problems, and completed the present invention. Here, the “work material” means a material in which a “layer” such as a scale or a lubricant film is formed on the surface of a metal “material” before being drawn.

  The present inventors examined a lubrication method using a resin-based film in order to obtain high lubricity in cold drawing of metal. In general, in order for a lubricating coating made of resin to have high lubricity, both a lubricating function that imparts slipping and a protective function that protects the coating are required. That is, in cold drawing of metal, the surface area of the work material is rapidly expanded while being ironed on the friction surface of the work material and the tool, so the lubricant always follows these changes. The malleability and ductility covering the friction surface and the strength to withstand the pressure are required. However, it has been substantially difficult to combine these functions with a single-layer coating.

  As a result of the study, if the glass transition temperature of the resin to be included in the lubricating coating is higher than the temperature immediately after the start of drawing, the resin coating cannot follow the change of the friction surface immediately after the start of processing, causing brittle fracture ( It was found that it was detached from the friction surface. On the other hand, when the glass transition temperature of the resin is lower than the temperature immediately after the start of the drawing process, the resin behaves like a viscous fluid, and therefore follows the change of the friction surface immediately after the start of the process. Investigated what can be done. In addition, even in severe processing by using a lubricating film for drawing processing having a specific glass transition temperature and further containing a specific amount of a compound containing a specific metal element and / or a resin cross-linked by its ions. It has been found that sufficient strength is obtained, film breakage does not occur, and the coated wax particles have a lubricating function against shearing and can reduce the frictional resistance during processing.

  Also, when forming a resin-based film on the material, from the viewpoint of adhesion, oil is removed by degreasing, and oxide scale is removed by pickling or shot blasting, etc., but a lubricating film for cold drawing processing Then, it was clarified that the adhesion to the oxide scale is high and the followability to the change of the friction surface of the oxide scale is also high. In addition, the oxide scale is an inorganic compound that is inert in itself, and is difficult to cause seizure even when it is rubbed against a metal surface such as a tool. On top of that, when the lubricating film is formed to be a workpiece, it has been found that cold drawing can be performed without causing seizure even under extremely severe conditions.

  The present invention will be described below.

The invention according to claim 1 is a method for cold drawing of a metal having a lubricating coating formed on the surface thereof, wherein a workpiece to be processed is a raw material and a film thickness formed on the surface of the raw material. Having an oxide scale of 0.1 μm or more and 1000 μm or less, and a lubricating film formed by further laminating on the oxide scale, the lubricating film comprising a resin and wax particles dispersed in the resin When the resin layer is 100% by mass, the resin is contained in an amount of 25 to 99% by mass, the glass transition temperature is 30 ° C. or less, and the typical metal element and the transition metal element The object is solved by providing a method for cold drawing of metal, characterized in that it is a resin crosslinked with a compound containing at least one metal element and / or its ions.

  The invention according to claim 2 is the method for cold drawing of a metal according to claim 1, wherein the raw material is a chromium-containing alloy containing Cr in an amount of 5% by mass or more and less than 16% by mass, and having an oxide scale. The film thickness is 0.2 to 1000 μm, and the oxide scale includes a Cr-based oxide.

  The invention according to claim 3 is the method of cold drawing of a metal according to claim 1, wherein the material is a chromium-containing alloy containing Cr in an amount of 16% by mass or more and less than 23% by mass, and having an oxide scale. The film thickness is 0.2 to 200 μm, and the oxide scale includes a Cr-based oxide.

  The invention according to claim 4 is the cold drawing method of the metal according to claim 1, wherein the raw material is a chromium-containing alloy containing 23% by mass or more of Cr, and the film thickness of the oxide scale is 0.1. And the oxide scale contains a Cr-based oxide.

The invention of claim 5 is a method for producing a pulling member of metal having a drawing step and before the drawing step, the film thickness on the material surface forming a 1000μm following oxide scale than 0.1μm And a step of forming a lubricating film further laminated on the oxide scale, the lubricating film comprising a resin layer including a resin and wax particles dispersed in the resin, When the resin layer is 100% by mass, the content is 25 to 99% by mass, the glass transition temperature is 30 ° C. or less, and at least one metal element of the typical metal element and the transition metal element is included. The object is solved by providing a method for producing a metal drawing material, which is a resin crosslinked with a compound and / or its ions.

  Further, in each of the above-described inventions, the cold drawing method and the drawing material manufacturing method of the present invention can be used as long as the above conditions are satisfied in a surface or a specific part where seizure is a problem. In particular, when the material is a tube, it is preferable that the above and other conditions are satisfied on both the inside and outside of the tube.

  According to the present invention, in a cold drawing method for a workpiece such as a metal tube, wire or rod and a method for producing a drawn material such as a metal tube, wire or rod, high lubricity that does not require a base by chemical conversion treatment. A lubricating coating having the following can be formed. Thereby, compared with a chemical film, capital investment, liquid management, etc. can be reduced. It is also possible to reduce the machining power in machining, extend the tool life by suppressing wear and seizure, and improve the product quality.

  The best mode of the present invention and preferred ranges thereof will be described below. In the present invention, “(meth) acrylic” means acrylic and methacrylic, and “(meth) acrylate” means acrylate and methacrylate.

  In the drawing method and the manufacturing method of the present invention, a method of drawing a workpiece having a scale formed on the surface of the material and a lubricant film formed by being further laminated on the scale, and thereby a pipe, A manufacturing method for obtaining a drawn material such as a wire or a rod is provided. The contents will be described below.

(1) Material First, the material will be described. The material used in the present invention may be any steel or alloy in which an oxide scale layer is formed at a high temperature, such as carbon steel, alloy steel, stainless steel, or Ni-based alloy. Among them, Cr-containing alloy steel, stainless steel, iron-chromium-nickel alloy, Cr-containing nickel-based alloy, etc., which are chromium-containing alloys, are particularly preferable.

  In general, a material having a Cr content of less than 5% by mass is a material that is difficult to seize, and often does not cause seizure depending on processing even without an oxide scale. On the other hand, when the Cr content is 5% by mass or more, the deformation resistance of the material tends to increase, and seizure is likely to occur in the drawing process. With such a material, extremely high seizure resistance can be obtained by combining the lubricity of the oxide scale layer, which will be described later, and the resin film, which will be described later with high adhesion. Therefore, the material of the material used in the present invention is a chromium-containing alloy containing 5% by mass or more of Cr, and an oxide scale layer having a predetermined thickness can be formed on the surface of the base material at a high temperature as described later. A material is preferred.

  Although the shape of a raw material is not specifically limited, What is necessary is just a raw material shape in the cold drawing process of a normal pipe | tube, a line | wire, and a rod.

  Prior to forming the oxide scale and the lubricating coating on the material, the material can be subjected to pretreatment such as degreasing with an alkaline degreasing agent, washing with water, pickling with hydrochloric acid or the like. By performing such pretreatment, the surface can be cleaned. Thereby, an oxide scale is formed appropriately or the adhesion of the lubricating coating is improved. In addition, it is possible to prevent the occurrence of scratches after drawing due to contamination such as earth and sand. Moreover, when forming a lubricating film using the composition for forming the below-mentioned lubricating film, the said composition spreads uniformly and can improve the adhesiveness of a lubricating film. Usually, pretreatment is performed in the order of degreasing, water washing, pickling, and re-watering, but the order is not particularly limited. The pretreatment may be performed by a conventional method and is not particularly limited.

  Furthermore, it is effective to increase the surface roughness of the material in order to improve the adhesion of the lubricating coating. Although the above-described pickling has its effect, there are other mechanical methods such as grinding with a rough abrasive paper or a metal brush, shot blasting, shot peening and the like before scale formation described later. Furthermore, phosphoric acid-based chemical conversion treatment with manganese phosphate or zinc phosphate, oxalate-based chemical conversion treatment, or the like is also effective.

(2) Oxide Scale Layer Next, the oxide scale layer will be described. In the present invention, an oxide scale layer is formed on the surface of the material. Thereby, the adhesiveness of a raw material and a resin film improves, and it can exhibit favorable seizure resistance.

The structure and composition of the oxide scale vary depending on the material and heating / cooling conditions, but in the case of carbon steel or low alloy steel, iron-based oxides Fe ₂ O ₃ , Fe ₃ O ₄ , and FeO are formed sequentially from the surface. Is done. Each thickness changes with conditions. In the case of an iron-chromium alloy containing Cr, when the Cr content is 5% by mass or more, the iron-based oxide scale is reduced, and an oxide scale containing FeCr ₂ O ₄ is generated instead. When the Cr content is 16% by mass or more, an oxide scale containing Cr ₂ O ₃ is generated, so that the iron-based oxide scale is further reduced and the oxide scale itself is thin. On the other hand, when the Cr content is 23% by mass or more, the oxide scale is mainly Cr ₂ O ₃ and the iron-based oxide scale is extremely reduced, so that the oxide scale itself is further thinned. In addition to the above, the oxide scale may contain oxides such as MnCr ₂ O ₄ , TiO ₂ , Al ₂ O ₃ , and SiO ₂ . The thickness of the oxide scale layer in the present invention means the total of the entire oxide scale layer.

  The thickness of the oxide scale layer is 1000 μm or less. This is because, in an oxide scale thicker than 1000 μm, the oxide scale peels off from the material and floats, and may be easily peeled off. In such a case, even if a lubricating film described later is formed on the oxide scale, both the oxide scale and the lubricating film are peeled off during the cold drawing process, and seizure is likely to occur at that portion. Preferably it is 500 micrometers or less, More preferably, it is 300 micrometers or less, More preferably, it is 200 micrometers or less. Moreover, although a minimum is not specifically limited, Preferably it is 0.1 micrometer or more. This is because if it is less than 0.1 μm, a sufficient effect of improving seizure resistance may not be obtained. More preferably, it is 1 micrometer or more, More preferably, it is 3 micrometers or more.

  Furthermore, when the Cr content of the material is 5% by mass or more and less than 16% by mass, it is preferable to form an oxide scale containing a Cr-based oxide having a thickness of 0.2 to 1000 μm. Thereby, even in such a material, the seizure resistance in the cold drawing process can be improved. The reason why the lower limit is set to 0.2 μm is that in such a material, if it is less than 0.2 μm, a sufficient effect of improving seizure resistance may not be obtained. Preferably it is 1 micrometer or more, More preferably, it is 3 micrometers or more. On the other hand, the upper limit is 1000 μm. This is because if it is thicker than 1000 μm, the oxide scale peels off from the material and floats up, and may be easily peeled off. In such a case, even if the lubricating coating is formed, both the oxide scale and the lubricating coating are peeled off during the cold drawing process, and seizure is likely to occur at that portion. Preferably it is 500 micrometers or less, More preferably, it is 300 micrometers or less.

  Further, when the Cr content of the material is 16% by mass or more and less than 23% by mass, the thickness of the oxide scale containing the Cr-based oxide is preferably 0.2 μm or more and 200 μm or less. Thereby, even such a material can sufficiently exhibit seizure resistance during processing. The reason why the lower limit is set to 0.2 μm is that, in this material, a sufficient effect of improving seizure resistance may not be obtained. Preferably it is 1 micrometer or more, More preferably, it is 3 micrometers or more. On the other hand, the upper limit is 200 μm. This is because if the thickness is greater than 200 μm, the material may be peeled off from the oxide scale and floated, and may be easily peeled off. Even if the lubricating coating is formed in such a case, both the oxide scale and the coating are peeled off during the cold drawing process, and seizure is likely to occur at that portion. Preferably it is 100 micrometers or less, More preferably, it is 50 micrometers or less.

  Furthermore, when the Cr content of the material is 23% by mass or more, the thickness of the oxide scale including the Cr-based oxide is preferably 0.1 μm or more and 30 μm or less. The reason why the lower limit is set to 0.1 μm is that, if it is smaller than this, it may not be possible to obtain a sufficient effect of improving seizure resistance. Preferably it is 0.5 micrometer or more, More preferably, it is 1 micrometer or more. On the other hand, the upper limit is 30 μm. This is because when the film thickness is greater than 30 μm, it peels off from the oxide scale and floats up and easily peels off. Even if a lubricating coating is formed in such a case, both the oxide scale and the lubricating coating are peeled off during cold drawing, and seizure is likely to occur at that portion. Preferably it is 20 micrometers or less, More preferably, it is 10 micrometers or less. The method for forming the above-described oxide scale will be described later.

(3) Lubricating film Next, the lubricating film will be described. The lubricating coating used in the drawing method and manufacturing method of the present invention includes a resin and wax particles dispersed in the resin to form a resin layer. The resin layer is further laminated on the scale formed on the surface of the material to form a lubricating coating.

  Slip is imparted by the wax particles of the lubricating coating, and the protective function of the lubricating coating is improved by the resin. Specifically, sufficient strength is obtained even in severe processing, film breakage does not occur, and the coating has a lubricating function with dispersed wax particles against shearing, reducing friction resistance during processing. Can be lowered. Thereby, for example, it is possible to reduce a load necessary for processing.

  In the present invention, the “resin” constituting the resin layer has a glass transition temperature of 30 ° C. or lower, preferably 26 ° C. or lower, more preferably 23 ° C. or lower, more preferably 15 ° C. or lower, and particularly preferably 10 ° C. or lower. Moreover, about the minimum of the range of glass transition temperature, it can set suitably, -85 degreeC is mentioned as the example. When the glass transition temperature exceeds 30 ° C., the lubricating coating cannot follow the increase in the surface area of the friction surface immediately after the start of cold drawing, resulting in brittle fracture and frequent desorption from the friction surface.

  The glass transition temperature can be measured by a method according to JIS K7121 “Plastic transition temperature measurement method” or dynamic viscoelasticity measurement. When the resin is a (meth) acrylic resin, the glass transition temperature can also be calculated from the glass transition temperature of the homopolymer of each ethylenically unsaturated monomer to be polymerized by the FOX equation. In addition, the said glass transition temperature can also be changed by selecting the kind etc. of resin suitably. Furthermore, it can be lowered by using a plasticizer and external plasticizing.

  The kind of resin used is not specifically limited. Therefore, the resin may be an uncrosslinked polymer or a crosslinked polymer. In the latter case, a compound containing at least one metal element of a typical metal element and a transition metal element and / or a resin crosslinked with ions thereof can be preferably applied. Examples of typical metal elements include alkali metals, alkaline earth metals, aluminum, and zinc. Among these, at least one selected from alkaline earth metals, aluminum, and zinc is preferable. Moreover, as a transition metal element, iron, copper, etc. can be mentioned, for example.

  Specific examples of the resin include (meth) acrylic resins, urethane resins, polyester resins, vinyl acetate resins, polyvinyl alcohol resins, polyamide resins, and fluorine resins. Resins having a glass transition temperature of 30 ° C. or lower as described above may be used alone or in combination of two or more. By setting it as the resin layer containing this specific resin, it can be set as a film with a high lubrication function.

  The (meth) acrylic resin may be a homopolymer or a copolymer as long as it is obtained by polymerizing one or more acrylic monomers. Moreover, there is no limitation in particular about the structure and kind. Examples of acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and octyl (meth) acrylate. Alkyl (meth) acrylate (the alkyl group preferably has 1 to 8, more preferably 1 to 6, particularly preferably 1 to 4 carbon atoms); methoxymethyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxymethyl ( Lower alkoxy lower alkyl (meth) acrylates such as meth) acrylate, ethoxyethyl (meth) acrylate, and methoxybutyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, etc. N-unsubstituted or substituted (especially lower alkoxy) such as N-methylolacrylamide, N-methylolmethacrylamide, N-butoxymethylacrylamide, and N-butoxymethylmethacrylamide Substituted) (meth) acrylamide having a methylol group; phosphonyloxy lower alkyl (meth) acrylates such as phosphonyloxymethyl (meth) acrylate, phosphonyloxyethyl (meth) acrylate, and phosphonyloxypropyl (meth) acrylate; Acrylonitrile; one or more of acrylic acid, methacrylic acid, etc. may be mentioned. In addition, said lower alkoxy and lower alkyl usually mean a C1-C5 alkoxy and alkyl, respectively, Preferably it is C1-C4, More preferably, it is 1-3.

  The (meth) acrylic resin is one or more of acrylic monomers and one or two of other ethylenic monomers such as styrene, methylstyrene, vinyl acetate, vinyl chloride, vinyltoluene, and ethylene. It may be a copolymer with more than one species. In that case, a copolymer containing 30 mol% or more of an acrylic monomer is preferred. Examples of the copolymer include a compound containing at least one metal element of a typical metal element and a transition metal element and / or an ionomer cross-linked with an ion thereof. Examples of typical metal elements include alkali metals, alkaline earth metals, aluminum, and zinc. Among these, at least one of alkaline earth metal, aluminum, and zinc is preferable. Moreover, as a transition metal element, iron, copper, etc. are mentioned, for example.

  The urethane resin is a synthetic resin having a urethane bond (—NHCOO—), and generally a resin obtained by a polyaddition reaction between a polyisocyanate compound having two or more isocyanate groups and a polyol having two or more active hydrogen groups is used. be able to. Examples of the polyol include polyester polyol and / or polyether polyol. The said urethane resin may be used individually by 1 type, and may use 2 or more types together.

  Examples of the polyester polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1, Low molecular weight polyols such as 4-butylene glycol, 3-methylpentanediol, hexamethylene glycol, hydrogenated bisphenol A, trimethylolpropane, and glycerin, succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid , Polyester compounds having hydroxyl groups at the ends obtained by reaction with polybasic acids such as terephthalic acid, trimellitic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, hexahydrophthalic acid, etc. One or two or more thereof.

  Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, neopentyl glycol, 1,2-butylene glycol, 1,3-butylene glycol, 1 , 4-butylene glycol, 3-methylpentanediol, hexamethylene glycol, bisphenol A, hydrogenated bisphenol A, trimethylolpropane, and polyols such as glycerin, or ethylene oxide and / or propylene oxide hyperadducts thereof, polyethylene glycol, Polyether glycol such as polypropylene glycol, polyethylene / propylene glycol, polycaprolactone polyol, polyolefin polyol, and One or more species of Li butadiene polyols.

  Examples of the polyisocyanate include one or more of linear aliphatic, branched aliphatic, alicyclic and aromatic polyisocyanates. Specifically, for example, tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, hydrogenated xylylene diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 2,4′-dicyclohexylmethane diisocyanate. , Isophorone diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, phenylene diisocyanate, xylylene diisocyanate Sulfonates, and one or more such tetramethylxylylene diisocyanate.

  The polyester resin is a synthetic resin having an ester bond, and generally, a resin obtained by a condensation reaction between a polybasic acid having two or more carboxyl groups and a polyol having two or more hydroxyl groups can be used. A polyester resin may be used individually by 1 type, and may use 2 or more types together. Examples of the polybasic acid include succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, and hexahydrophthalic acid. 1 type or 2 types or more are mentioned. On the other hand, examples of the polyol include polyester polyol and polyether polyol, and more specifically, for example, the polyester polyol and polyether polyol described in detail in the section of urethane resin.

  A vinyl acetate resin is a resin obtained by polymerization of vinyl acetate. The vinyl acetate resin also includes a resin in which less than 50% of vinyl acetate units in the polyvinyl acetate resin are hydrolyzed. Further, the vinyl acetate resin is obtained not only by homopolymer of vinyl acetate but also by copolymerization of vinyl acetate and other monomers (for example, olefin such as ethylene), and the vinyl acetate unit is 50 mol% or more. Copolymers are also included. A vinyl acetate resin may be used individually by 1 type, and may use 2 or more types together.

  The polyvinyl alcohol resin is usually obtained by hydrolyzing polyvinyl acetate. As the polyvinyl alcohol resin, not only a completely hydrolyzed product but also a polyvinyl alcohol resin having a hydrolysis degree of 50% or more can be used. Furthermore, the polyvinyl alcohol resin includes an ethylene unit, and also includes a copolymer in which the ethylene unit is 50 mol% or less. A polyvinyl alcohol resin may be used individually by 1 type, and may use 2 or more types together.

  The polyamide resin is a synthetic resin having an amide bond, and generally a resin obtained by a condensation reaction of a polybasic acid having two or more carboxyl groups and a polyamine having two or more amino groups can be used. Examples of the polybasic acid include succinic acid, glutaric acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, tetrahydrophthalic acid, endomethylenetetrahydrophthalic acid, hexahydrophthalic acid and the like. On the other hand, polyamines include hydrazine, methylenediamine, ethylenediamine, propylenediamine, butylenediamine, hexanediamine, ethylaminoethylamine, methylaminopropylamine, iminobispropylamine, diethylenetriamine, triethylenetetramine, polyethyleneimine, diaminobenzene, triamino. Examples thereof include benzene, diaminoethylbenzene, triaminoethylbenzene, diaminoethylbenzene, triaminoethylbenzene, polyaminonaphthalene, polyaminoethylnaphthalene, and N-alkyl derivatives and N-acyl derivatives thereof. A polyamide resin may be used individually by 1 type, and may use 2 or more types together.

  The type of fluororesin is not particularly limited as long as it is a resin containing fluorine in the molecule. Examples of the fluorine-based resin include (meth) acrylic resins containing fluorine in the molecule. Further, the fluororesin may be a copolymer with another copolymerizable monomer. More specifically, examples of the fluororesin include, for example, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, trifluoromethyl polyacrylate, pentafluoroethyl polyacrylate, and fluoroalkyl (meth) acrylate (meth) acrylate. Examples thereof include alkyl acrylate copolymers. A fluorine-type resin may be used individually by 1 type, and may use 2 or more types together.

  In the lubricating coating applied to the drawing method and the drawing material manufacturing method of the present invention, as the resin constituting the resin layer, in addition to a resin composed of one or more of the above resins, each of the above resins A composite resin composed of one or more of the above and other resins may be used. As this composite resin, for example, a resin obtained by mixing one or more of the above resins and other resin raw materials, and various resins are grafted, blocked, etc. A composite resin having a structure derived from a plurality of monomers having a substituent can be used. In addition, a resin that is organically crosslinked or ionically crosslinked with a metal after film formation can be used.

  The content ratio of the resin having a glass transition temperature of 30 ° C. or less in the resin layer is 25 to 99% by mass, preferably 29.5 to 90% by mass, more preferably 30 when the resin layer is 100% by mass. -80 mass%, More preferably, it is 30-70 mass%, Most preferably, it is 30-60 mass%. When the content ratio is less than 25% by mass, the lubricating coating cannot sufficiently follow the expansion of the surface area of the workpiece during the drawing process. On the other hand, when the content ratio is greater than 99% by mass, no significant improvement in properties such as seizure resistance, moldability, and workability is observed, and it is difficult to recognize economic benefits.

  Moreover, in order to further improve the lubrication effect at the time of a drawing process, the said resin can also be made to contain an extreme pressure additive as needed. The inclusion of such an extreme pressure additive is preferable because the lubrication performance in the extreme pressure lubrication region is improved and the seizure prevention effect becomes more remarkable.

  Examples of extreme pressure additives include sulfur-based extreme pressure additives, phosphorus-based extreme pressure additives, and chlorine-based extreme pressure additives. In addition, these may be used individually by 1 type and may use 2 or more types together. Examples of the sulfur-based extreme pressure additive include sulfurized olefins, sulfurized esters, thiocarbonates, dithiazoles, polythiazoles, thiols, thiocarboxylic acids, thiocols, sulfur, (poly) sodium sulfide, and the like. . Examples of the phosphorus-based extreme pressure additive include condensed phosphates such as sodium tripolyphosphate, and (sub) phosphate esters such as tricresyl phosphate. Furthermore, examples of the chlorinated extreme pressure additive include chlorinated paraffin, chlorinated fatty oil, polyvinylidene chloride, polyvinyl chloride, and vinylidene chloride-acrylic copolymer.

  The content ratio of the extreme pressure additive in the resin layer is preferably 0.5 to 74.5% by mass in terms of solid content, more preferably 1 to 70% by mass when the resin layer is 100% by mass. More preferably, it is 5-69.5 mass%. When the content ratio of the extreme pressure additive is within the above range, it is preferable because the lubrication performance in the extreme pressure lubrication region can be further improved and the seizure prevention effect can be further improved.

  Moreover, in the lubricating coating applied to this invention, in order to improve the lubrication effect at the time of a drawing process, a fine particle can also be contained in a resin layer as needed. The inclusion of such fine particles is preferable because the shear strength and adhesion strength of the resin layer is increased, and the presence of the fine particles at the processing interface suppresses contact between metals and makes the seizure prevention effect more remarkable.

Examples of the fine particles include solid lubricants that can be expected to reduce friction when they themselves have lubricity. Specific examples of such solid lubricants include molybdenum disulfide, tungsten disulfide, calcium stearate, mica, graphite, polytetrafluoroethylene (PTFE), other lubricating resins, and composite oxides having an oxygen-defect perovskite structure ( Sr _x Ca _1-x CuO _y ) and the like. Other, carbonate _{(Na 2 CO 3, CaCO 3} , MgCO 3 alkali metal or alkaline earth metal carbonates such as such), silicate _{(M x} O y SiO ₂ [M: alkali metal, alkaline earth metal ], Metal oxides (oxides of typical metal elements, oxides of transition metal elements, and complex oxides containing such metal elements [Al ₂ O ₃ / MgO, etc.]), sulfides (PbS, etc.) , Fluoride (CaF ₂ , BaF ₂ etc.), carbide (SiC, TiC), nitride (TiN, BN, AlN, Si ₃ N ₄ etc.), cluster diamond, and fullerene C ₆₀ or C ₆₀ and C ₇₀ Examples of such a mixture include fine particles that can suppress direct contact between metals without extremely reducing the friction coefficient and can be expected to have an anti-seizure effect. Examples of the oxide of the typical metal element include Al ₂ O ₃ , CaO, ZnO, SnO, SnO ₂ , CdO, PbO, Bi ₂ O ₃ , Li ₂ O, K ₂ O, Na ₂ O, and B ₂ O. ₃ , SiO ₂ , MgO, In ₂ O _{3 and the} like. Among these, the typical metal element is preferably an alkaline earth metal, aluminum, or zinc. Examples of the oxide of the transition metal element include TiO ₂ , NiO, Cr ₂ O ₃ , MnO ₂ , Mn ₃ O ₄ , ZrO ₂ , Fe ₂ O ₃ , Fe ₃ O ₄ , Y ₂ O ₃ , and CeO _2. , CuO, MoO ₃ , Nd ₂ O _3, and H ₂ O ₃ . Among these, those in which the transition metal element is iron or copper are preferable.

  In addition, when the dissociation group contained in the resin in the resin layer is in a free form (for example, a free carboxyl group), avoid using fine particles (for example, a metal compound) reactive with the free group, or In anticipation of dissolution of the fine particles due to the reaction with the free radicals, the fine particles may be used in excess. Moreover, the said microparticles | fine-particles may be used individually by 1 type, and may use 2 or more types together.

  Further, the average particle diameter of the fine particles is not particularly limited, and can be set in various ranges as necessary. The average particle size of the fine particles is usually 10 μm or less (for example, 0.001 to 10 μm), preferably 5 μm or less, more preferably 2 μm or less. When the fine particles are flaky, the average particle size is the average value of the maximum particle sizes. Some types of fine particles have a wide particle size distribution, but a desired effect can be obtained if 80% of the total fine particles are within the above range by volume. When the average particle diameter of the fine particles is 0.005 μm or more, it is preferable that the particles are prevented from aggregating in the resin, uniform dispersion is facilitated, and removal of the fine particles is facilitated after use. On the other hand, when the average particle size of the fine particles is 10 μm or less, the adhesion strength is improved, and as a result, the seizure prevention effect due to the metal-to-metal contact is improved, which is preferable.

The fine particles having the above average particle diameter are commercially available, and may be appropriately selected from commercially available products in consideration of dispersibility in the resin and / or wax used together. Examples of commercially available products (average particle diameters in parentheses) include “NanoTek (registered trademark)” manufactured by CI Kasei Co., Ltd., Al ₂ O ₃ (33 nm), TiO ₂ (30 nm), Fe ₂ O ₃ (21 nm), ZnO (31 nm), Y ₂ O ₃ (20 nm), CeO ₂ (11 nm), Mn ₃ O ₄ (38 nm), SiO ₂ (12 nm), etc. 70-130 nm), P50 (0.48-0.58 μm), P100 (0.9-1.1 μm), etc. “SEC Fine Powder SGP” (3 μm high-purity artificial graphite) manufactured by ESC, SiO manufactured by Nippon Aerosil from ₂ "AEROSIL 50" (30 nm), "AEROSIL 200" (12 nm), "AEROSIL 300" (7 nm), or _Al 2 _{O 3} "C" (13 nm), from TiO ₂ "T805" and "P25" (both 21 nm) or the like, "SNOWTEX C" of SiO ₂ manufactured by Nissan Chemical Industries, Ltd. and "Snowtex N" (both 20 nm) or the like, Ishihara Techno “TTO-55 (B)” (30-50 nm) from ultra-fine titanium oxide manufactured by Kamishima Chemical Industries, Ltd. “Calcies P” (0.10 μm), “Calcys PL10” (0.09 μm) “PLS2301” (40 nm), “EC” (1.0-2.0 μm) from light calcium carbonate, “Cluster Diamond” (5 nm) available from Tokyo Progress System, etc. “-40” (0.18 μm), “L-2” (5 μm), etc. ) "TLP-10F-1" from "(2μm), etc., Sumitomo cement made of _{SiC (10nm), ZrO 2 (} 30nm), like can be mentioned Osaka shipyard made of" molybdenum disulfide C powder "(1.2μm) It is done.

  In addition, when the fine particles are contained, the content ratio of the fine particles in the resin layer is not particularly limited, and can be appropriately adjusted as necessary. Specifically, when the resin layer is 100% by mass, it is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 1% by mass. is there. By setting the content ratio of the fine particles in the above range, it is preferable because the shear strength and adhesion strength of the film formed when dried can be improved.

  Next, the wax particles will be described. The “wax particles” contained in the resin layer are melted by heat generated during processing as a lubricating coating component, and have an action of improving the slipping property of the coating. The structure and type of the wax particles are not particularly limited. As the wax particles, for example, natural wax and / or synthetic wax can be preferably used. More specifically, for example, one or two of paraffin wax, microcrystalline wax, petrolactam wax, (oxidized) polyethylene, (oxidized) polypropylene, carnauba wax, montan wax, candelilla wax, rice wax, lanolin and the like. The above can be mentioned. Further, the wax particles in the present invention include a polyethylene resin and a polypropylene resin.

  Further, the physical properties of the wax particles are not particularly limited. For example, the average particle size of the wax particles can be in various ranges as required. The average particle size of the wax particles is usually 10 μm or less (for example, 0.001 to 10 μm), preferably 5 μm or less, more preferably 3 μm or less, more preferably 1 μm or less, and particularly preferably 0.001 to 1 μm. When the average particle size is in the above range, it is preferable because the coating film can be provided with slipperiness without decreasing the strength of the coating film. The wax particles have a solid or viscosity at 100 ° C. of 10 mPa · s or more, preferably 20 mPa · s or more, and more preferably 100 mPa · s or more. In this case, it is preferable in the plastic working of the metal in the cold, since it exhibits more excellent lubricity even under severe working conditions where seizure is likely to occur.

  Furthermore, the content ratio of the wax particles in the resin layer is preferably 0.5 to 74.5% by mass, more preferably 9.5 to 70% by mass, when the resin layer is 100% by mass. Preferably it is 19.5-69.5 mass%, More preferably, it is 29.5-69.5 mass%. When this content ratio is in the above range, it is preferable in cold plastic processing because it exhibits excellent lubricity even under severe processing conditions in which seizure is likely to occur.

  Furthermore, in the lubricating coating applied to the present invention, the resin layer is added to a general plastic working oil in addition to the resin, wax particles, fine particles, and extreme pressure additive, as long as the object of the present invention is not impaired. Additives that have been added can be added. Examples of such additives include pH adjusters, viscosity adjusters, preservatives, and antifoaming agents. Further, if necessary, a plasticizer, an oily agent, other extreme pressure additives, etc. may be used in combination. In addition, the resin layer may or may not contain a resin having a glass transition temperature exceeding 30 ° C. as another resin. Here, “not contained” includes not only a case where it is not contained at all, but also a case where a trace amount of a resin having a glass transition temperature exceeding 30 ° C. is contained within a range not impairing the object of the present invention. .

  The formation of the lubricating coating on the workpiece is preferably as uniform as possible. This is because if there is a change in thickness in the axial direction or circumferential direction of the work material, it takes time to dry the thick part when supplying the composition for forming the lubricating film and then drying it. It is. If sufficient drying is not possible, the lubricating coating may peel off during cold drawing and seizure may occur. The drying time is not particularly limited, but can be appropriately determined according to the supply thickness of the composition for forming the lubricating coating.

Moreover, there is no limitation in particular about the weight, thickness, etc. of a lubricating film, It can be set as a various range as needed. For example, the coating weight of the resin layer is preferably 1 g / m ² or more from the viewpoint of preventing seizure, and is preferably 30 g / m ² or less from the viewpoint of cost. More preferably, it is 3-20 g / m < ² >, More preferably, it is 5-15 g / m < ² >.

  In the present invention, a drawing method for drawing a workpiece as described above is provided. Accordingly, seizure can be prevented even when severe deformation occurs on the contact surface between the workpiece and the tool. More specifically, although the workpiece before drawing is not necessarily along the tool, the workpiece is deformed along the tool at the same time as the drawing starts. At this time, a portion having a high surface pressure locally occurred on the contact surface, and conventionally, the lubricant film peeled off and seizure occurred. However, in the drawing method of the present invention, seizure does not occur because the lubricating coating is optimized so that it can follow the change of the friction surface with the lubricating coating having high adhesion.

  Next, one embodiment of the method for producing a drawn material of the present invention will be described. The manufacturing method of the present invention is a method for manufacturing a metal drawing material having a drawing process, and a step of forming an oxide scale on a material before the drawing process, and further laminating the oxide scale. Forming the lubricating coating described above. Each step will be described below.

  The method for forming the oxide scale on the material is not particularly limited. Strictly speaking, oxide scale is also slightly generated on cold machined surfaces. However, these are thicknesses that hardly contribute to the prevention of seizure in the drawing process. Therefore, as described above, in order to generate an oxide scale having a predetermined film thickness that can contribute to prevention of seizure, processing at a high temperature such as heat treatment is required. The method of treatment at such a high temperature is not particularly limited. For example, in addition to heat treatment in a general heating furnace, methods such as high-frequency heating and energization heating in which a current is directly passed through the material can be used. In addition, when the so-called hot working is in the previous process under such conditions that an oxide scale is generated, a raw material that has been hot worked can be used. The thickness of the generated oxide scale varies depending on the heat treatment conditions, that is, the heating temperature, time, atmosphere, material quality, and the like. As for the heating temperature, in the case of general carbon steel, oxide scale starts to be generated from around 600 ° C., but industrially, it is preferably 700 ° C. or higher and below the temperature at which the material melts. In an alloy having a Cr content of 5% by mass or more, the temperature is preferably 800 ° C. or more. The atmosphere is preferably an oxidizing atmosphere from the viewpoint that oxidation can be promoted.

  In the step of forming the lubricating coating by laminating the oxide scale, the method for forming the lubricating coating satisfying the above conditions is not particularly limited. For example, a material containing an oxide scale is immersed in a tank containing a composition for forming a lubricating coating, or the composition for forming a lubricating coating is oxidized using a nozzle. The method of spraying on the raw material in which the scale was formed can be mentioned. The aspect of the composition will be described later.

  Further, the method for adjusting the thickness of the lubricating coating is not particularly limited. For example, the thickness can be adjusted by the difference in temperature and time for passing through the drying zone. Here, the drying method is not particularly limited. Examples thereof include natural drying and forced drying. Further, as forced drying, any method such as a method of irradiating ultraviolet rays, a method of applying hot air, a method of preheating a material or a mold, a method of drying by high frequency heating, etc. can be adopted. As the forced drying conditions, it is preferable to carry out at 60 to 150 ° C. for about 10 to 60 minutes as described above.

  Alternatively, the lubricating coating can be formed by batch processing. That is, it is also possible to supply a composition for forming a lubricating film at a time to a predetermined number of elementary tubes, and simultaneously put it in a drying furnace or the like to form a lubricating film. In addition, when the material is a tube, after applying the solution by immersing the inner surface of the tube in a tank containing a composition for forming a lubricating coating, or spraying a nozzle into the inner surface of the raw tube The lubricating coating may be formed by placing in a drying furnace at 60 to 150 ° C. or passing through a drying zone. The lubricating film remaining on the surface of the drawing material after the drawing process is completely removed with a solvent or a cleaning agent in a subsequent process.

  The drawing process of the workpiece formed as described above is not particularly limited, and is performed by a normal drawing process.

  According to such a method for producing a drawn material such as a metal tube, wire, or bar, a lubricating coating that does not require a base by chemical conversion treatment is used, and seizure can be prevented even during processing with severe processing conditions.

  Next, the composition supplied in order to form the above-mentioned lubricating film in the manufacturing method of the drawing material of this invention is demonstrated. The composition contains a resin having a glass transition temperature of 30 ° C. or less and wax particles in a solvent. As described above, in the conventional chemical conversion film treatment, a lubricant is applied onto the formed chemical conversion film, and therefore, including water washing and pickling, many treatment steps are required. On the other hand, if a lubricating film is formed using a composition, a chemical conversion treatment and the accompanying pickling and water washing can be omitted. As a result, it is possible to easily form a lubricating coating, to prevent environmental pollution caused by waste generated by the conventional chemical conversion coating processing, and to omit the provision of equipment for such waste processing. it can.

  Examples of the “solvent” include water, alcohols, ether solvents, acetate solvents, ketone solvents, hydroxyamines, dimethyl sulfoxide and the like. These can be used individually by 1 type or in combination of 2 or more types. The solvent is considered to be involved in the formation of a tough resin layer. It is preferable to use water or a solvent containing at least water as the solvent because a tough film can be more reliably formed. Examples of the solvent containing at least water include a mixed solvent composed of water and the above-described solvent other than water. More specifically, for example, a water-alcohol solvent composed of water and the above alcohols can be used.

  Examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, n-butanol, 2-butanol, t-butanol, 2-ethylbutanol, 2-ethylhexanol, 3-methyl-3-methoxybutanol, Examples include benzyl alcohol, phenol, ethylene glycol, propylene glycol, 1,3-butyldiol, 2-ethyl-1,3-hexanediol, 3-methyl-1,3-butanediol, and glycerin.

  Examples of ether solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol diethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether, ethylene glycol dialkyl ethers, and diethylene glycol. Diethylene glycol monoalkyls such as monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol dialkyl ethers, polyethylene glycol monoalkyl ethers, polyethylene glycol dialkyl ethers Tellurium, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol diethyl ether, propylene glycol monopropyl ether, propylene glycol monoalkyl ethers such as propylene glycol monobutyl ether, propylene glycol dialkyl ethers, dipropylene glycol monomethyl ether, Dipropylene glycol monoalkyl ethers such as dipropylene glycol monoethyl ether, dipropylene glycol diethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, dipropylene glycol dialkyl ethers, polypropylene glycol monoalkyl ethers, polypropylene glycol The Ruki ethers, 1,4-dioxane, tetrahydrofuran and the like.

  Examples of the acetate solvent include the above-mentioned alcohols or acetylated products of ether solvents having a hydroxyl group.

  Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-methyl-3methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone. , N, N-dimethylformamide and the like.

  Examples of hydroxyamines include monoethanolamine, N-ethylethanolamine, Nn-butylethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, N, N-dibutylethanolamine, Examples include diethanolamine, N-ethyldiethanolamine, Nn-butyldiethanolamine, triethanolamine, isopropanolamine, N- (β-aminoethyl) isopropanolamine, N, N-diethylisopropanolamine and the like.

  The above description applies to the “resin having a glass transition temperature of 30 ° C. or lower” as it is. Moreover, the form at the time of suspending or disperse | distributing resin whose glass transition temperature is 30 degrees C or less in a solvent is not specifically limited. For example, it may be a melt of a resin having a glass transition temperature of 30 ° C. or lower, or water, an organic solvent (alcohol, mineral oil, mineral spirit, methyl ethyl ketone, “Freon” (trade name), etc.), or water and an organic solvent. Alternatively, a solution or dispersion dissolved or dispersed in the mixed solvent may be used. Moreover, the form which mixes at the time of use by preparing 2 or more types of containing liquid containing a part of resin which forms a resin layer may be sufficient.

  Furthermore, when a resin having a glass transition temperature of 30 ° C. or lower is suspended or dispersed in a solvent, a plasticizer may be used as necessary. By using such a plasticizer, a resin having a glass transition temperature of 30 ° C. or lower can be uniformly suspended or dispersed. Furthermore, the glass transition temperature of a resin having a glass transition temperature of 30 ° C. or lower can be lowered. A plasticizer is not specifically limited, The compound generally used as a plasticizer for resin can be used. Specific examples include phthalic acid esters, adipic acid esters, sebacic acid esters, trialkyl trimellitic acid, (phosphite) phosphoric acid esters, chlorinated paraffins, and the like. These may be used alone or in combination of two or more.

  The above description applies to the “wax particles”. The form in which the wax particles are suspended or dispersed in the solvent is not particularly limited. For example, a water dispersion or an emulsion of wax particles may be contained in the solvent, or the wax particles may be contained as they are.

  In the composition for forming a lubricating coating applied to the drawing method or drawing material manufacturing method of the present invention, it is necessary when the resin and wax particles having a glass transition temperature of 30 ° C. or lower are suspended or dispersed in a solvent. Accordingly, a surfactant can also be used. By using such a surfactant, the resin and the wax particles can be uniformly suspended or dispersed. Moreover, the resin layer formed on the surface of the material has good lubricity and can effectively prevent the material and the mold from being seized.

  As the surfactant, any of a nonionic surfactant, an anionic surfactant, an amphoteric surfactant and a cationic surfactant can be used. Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyalkylene (ethylene and / or propylene) alkyl phenyl ether, polyethylene glycol (or ethylene oxide) and higher fatty acids (for example, straight chain having 12 to 18 carbon atoms). And polyoxyethylene sorbitan alkyl esters composed of sorbitan, polyethylene glycol and higher fatty acids (for example, linear or branched fatty acids having 12 to 18 carbon atoms). Etc. Examples of the anionic surfactant include fatty acid salt, sulfate ester salt, sulfonate salt, phosphate ester salt, and dithiophosphate ester salt. Examples of amphoteric surfactants include amino acid type and betaine type carboxylates, sulfate esters, sulfonates, and phosphate ester salts. Examples of the cationic surfactant include aliphatic amine salts and quaternary ammonium salts. Surfactant may be used individually by 1 type and may be used in combination of 2 or more type.

  Moreover, in order to further improve the lubricating effect at the time of a drawing process, the said composition can also contain an extreme pressure additive as needed. The above description applies to the extreme pressure additive. Furthermore, in order to improve the lubricating effect at the time of drawing, the composition may contain fine particles as necessary. The above description also applies to fine particles.

  In addition, when the fine particles are contained, the content ratio of the fine particles in the resin layer is not particularly limited, and can be appropriately adjusted as necessary. Specifically, when the resin layer is 100% by mass, it is preferably 0.01 to 10% by mass, more preferably 0.01 to 5% by mass, and still more preferably 0.05 to 1% by mass. is there. By setting the content ratio of the fine particles in the above range, it is preferable because the shear strength and adhesion strength of the film formed when dried can be improved.

  The method for mixing the fine particles is not particularly limited as long as a composition in which the fine particles are uniformly dispersed is obtained. For example, if the fine particles are fine particles that are not reactive with the reaction components used for the synthesis of the resin, the fine particles may be included during the synthesis of the resin. Moreover, it can carry out by the method of mixing solid microparticles | fine-particles simultaneously with resin and wax particle | grains melt | dissolved or disperse | distributed to the solvent.

  In addition to the solvent, the resin, the wax particles, the fine particles, the extreme pressure additive, the surfactant and the plasticizer, the composition is added to a general plastic working oil as long as the object of the present invention is not impaired. Additives can be added. Examples of such additives include pH adjusters, viscosity adjusters, preservatives, crosslinking agents, and antifoaming agents. Further, other extreme pressure additives, oily agents and the like may be used in combination as necessary. Further, the composition may or may not contain a resin having a glass transition temperature exceeding 30 ° C. As used herein, “not contained” includes a trace amount of a resin having a glass transition temperature exceeding 30 ° C. as long as it is not contained at all, as long as the object of the present invention is not impaired. This includes cases where

  Next, the embodiment will be described in more detail. However, the present invention is not limited to this embodiment. In this example, an example corresponding to the present invention was set as an example of the present invention, an example not corresponding to the present invention was set as a comparative example, and the presence or absence of seizure was evaluated when a workpiece was formed and drawn under each condition. .

First, conditions in the present embodiment will be shown.
(I) Material The material used was a steel pipe having an outer diameter of 25.4 mm, an inner diameter of 21.4 mm, and a length of 800 mm. There are three types of materials: STBA25 equivalent (Cr content is 5.3 mass%) boiler / heat exchanger alloy steel pipe, SUS304 equivalent stainless steel pipe, and high alloy steel pipe (25 mass% Cr-35 mass% Ni). is there.
(Ii) Oxidized scale The surface of the above-mentioned material was prepared as-ground (comparative example) and one that produced oxidized scale. The oxide scale was generated in a mixed gas atmosphere of air and water vapor. Conditions and film thickness are shown below.
-STBA25 equivalent steel pipe 1: heated at 1000 ° C ± 30 ° C for 40 minutes, film thickness 180 µm
STBA25 equivalent steel pipe 2: Heated at 1000 ° C ± 30 ° C for 5 hours, film thickness 1300μm
SUS304 steel pipe: Heated at 1000 ° C. ± 30 ° C. for 3 hours, film thickness 40 μm
・ High alloy steel pipe: Heated at 1200 ℃ ± 30 ℃ for 5 hours, film thickness 8μm
The film thickness was measured from an optical micrograph of a cross section when each steel pipe was cut and embedded as a micro sample.
(Iii) Composition components Table 1 shows the components of the composition for forming a lubricating coating applied in this example.

Here, the types A to F of the components described in Table 1 are as follows.
A is composition No. 1 is a resin corresponding to the present invention used in No. 1, and has a glass transition temperature (Tg) of 5 ° C. Specifically, it is as follows. That is, a separable flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 250 parts by mass of water, 0.5 parts by mass of sodium lauryl sulfate, and 0.5 parts by mass of polyoxyethylene alkyl ether. The temperature was raised to 80 ° C. Thereafter, the internal temperature was kept at 80 ° C., and 0.1 parts by mass of potassium persulfate was added as a polymerization initiator. After dissolution, 0.45 parts by mass of methyl methacrylate, 0.5 parts by mass of butyl acrylate, 0 parts of methacrylic acid A mixed solution of 0.05 parts by mass and 0.01 parts by mass of lauryl mercaptan was charged and allowed to react for 1 hour. Subsequently, after completion of the reaction, a mixture of 45 parts by mass of methyl methacrylate, 50 parts by mass of butyl acrylate, 5 parts by mass of methacrylic acid, and 1 part by mass of lauryl mercaptan, and 1 part by mass of potassium persulfate in 20 parts by mass of water. An aqueous solution in which was dissolved was continuously added over 4 hours to react. After completion of the addition, aging was further performed for 4 hours, and the emulsion was cooled to room temperature. Thereafter, 32.9 parts by mass of the calcium crosslinking agent was added dropwise over 30 minutes. Subsequently, after heating at 85 degreeC for 6 hours and making a crosslinking reaction advance, it cooled to normal temperature and adjusted with water so that solid content might be 20 mass%, and the resin solution was prepared. In addition, the said calcium crosslinking agent is a dispersion liquid which consists of 5 mass parts of calcium oxides well ground in a mortar and 95 mass parts of water.

  B is composition No. 2 is a resin having a Tg of 46 ° C. That is, Tg is higher than 30 ° C. Specifically, Daiichi Kogyo Seiyaku Co., Ltd. water-based urethane resin (solid content: 30 mass%) was applied.

  As described above, the glass transition temperatures of the resin components in the resin solutions of resins A and B are 5 ° C. and 46 ° C., respectively. The glass transition temperature of the resin A is a value calculated from the FOX equation and is the glass transition temperature of the resin before crosslinking. Moreover, the glass transition temperature of resin B is the value published in the said product pamphlet.

  C is the composition No. 1 and no. 2 is a wax component used in any of the above. Specifically, 75 parts by mass of water, 20 parts by mass of polyethylene oxide (softening point: 138 ° C., form at 100 ° C .: solid), 5 parts by mass of polyoxyethylene alkyl ether, and 0.2 parts by mass of potassium hydroxide In addition to the high-pressure vessel, the mixture was stirred at 160 ° C. for 3 hours and then cooled to room temperature to prepare an emulsified wax solution (solid content: 25%). The average particle size of the wax particles is 0.05 μm.

  D is composition No. 1 and no. It is a solvent used for both of these, specifically water.

  E is composition No. 1 is a solvent used. Specifically, diethylene glycol monoethyl ether manufactured by Dainippon Ink & Chemicals, Inc. was used.

  F is composition No. 1 is a fine particle added only to 1 and is calcium oxide. Specifically, calcium oxide made by Wako Pure Chemical Industries, Ltd., finely divided by a ball mill was used.

(Iv) lubricating coating forming lubricating coating, so that the composition shown in Table 1 the average coating weight after drying of 20 ± 2g / m ^2, was applied to the material, then 1 hour drying at 80 ° C. did. As a result, a resin layer was formed on the surface of the material to obtain a workpiece. The film thickness of the coating was measured with a film thickness meter (MiniTest 3100, manufactured by Electro Physics).

(V) Drawing Processing FIG. 1 schematically shows an outline of the drawing processing. In the drawing process, the diameter is obtained by sandwiching between the dies 1 and 1 for processing the outside of the pipes 3 and 3 which are workpieces and the plug 2 for processing the inside and pulling in the direction indicated by the arrow A in FIG. Processing to reduce. Accordingly, the degree of processing (surface reduction rate, etc.) varies depending on the diameters of the dies 1, 1 and the plug 2 with respect to the diameters of the tubes 3, 3. In this example, the drawing of combinations of 8 types of dies and plugs a to h was performed. Table 2 shows specific values. The drawing speed was 6 m / min.

(Vi) Evaluation Criteria Evaluation of the seizure property was performed by visually judging the presence or absence of seizure. However, the three types of materials used in this example have different differences in workability, so the evaluation cannot be made uniform. Therefore, the evaluation criteria for the “◯” evaluation as shown below were set. Specifically, it is as follows.
STBA: When a pull-out test is performed under the conditions a to h shown in Table 2, and seizure does not occur even when the area reduction is 47.2% (reference f) or more. SUS304: Table When a pull-out test is performed under the conditions a to h shown in FIG. 2 and seizure does not occur even when the area reduction is 43.9% (reference e) or higher. High alloy steel: Table 2 When a pull-out test is performed under the conditions indicated by the symbols a to h, and seizure does not occur even when the area reduction ratio is 42.3% (symbol d) or more.

  The test was conducted under the above conditions. Next, the results will be described. Table 3 lists the results.

  As can be seen from the results shown in Table 3 as “Examples of the present invention”, in any case, the occurrence of seizure can be suppressed by applying the film thickness of the oxide scale and the type of the lubricating coating to the present invention. It becomes. On the other hand, in other examples shown as “comparative examples”, it is found that seizure occurred and proper processing was not performed. As described above, in this embodiment, the effect of the present invention is remarkably exhibited.

  Although the present invention has been described with reference to the most practical and preferred embodiments at the present time, the present invention is not limited to the embodiments disclosed herein. The invention can be changed as appropriate without departing from the scope or spirit of the invention that can be read from the claims and the entire specification, and the metal drawing method and the drawing material manufacturing method involving such changes are also disclosed in the present invention. Should be understood as being included in the scope.

It is the figure which showed typically the outline | summary about the drawing process of the pipe | tube in an Example.

Explanation of symbols

1 Die 2 Plug 3 Workpiece (drawn after processing)

Claims (5)

A cold drawing method for a metal having a lubricating film formed on the surface,
Work material to be processed is
Material,
An oxide scale having a thickness of 0.1 μm or more and 1000 μm or less formed on the surface of the material;
The lubricating film formed by further laminating on the oxide scale,
The lubricating coating comprises a resin layer containing a resin and wax particles dispersed in the resin,
The resin is contained in an amount of 25 to 99% by mass when the resin layer is 100% by mass, has a glass transition temperature of 30 ° C. or less, and at least one of a typical metal element and a transition metal element A method for cold drawing of a metal, which is a resin crosslinked with a compound containing a metal element and / or ions thereof. The material is a chromium-containing alloy containing Cr in an amount of 5% by mass or more and less than 16% by mass,
The method for cold drawing of metal according to claim 1, wherein the oxide scale has a thickness of 0.2 to 1000 μm and the oxide scale contains a Cr-based oxide. The material is a chromium-containing alloy containing Cr in an amount of 16% by mass or more and less than 23% by mass,
The method for cold drawing of metal according to claim 1, wherein the oxide scale has a thickness of 0.2 to 200 μm and the oxide scale contains a Cr-based oxide. The material is a chromium-containing alloy containing 23 mass% or more of Cr,
2. The method of cold drawing metal according to claim 1, wherein the oxide scale has a thickness of 0.1 to 30 μm and the oxide scale contains a Cr-based oxide. A method for producing a metal drawing material having a drawing process,
Before the drawing process,
Forming an oxide scale having a thickness of 0.1 μm or more and 1000 μm or less on the surface of the material;
Forming a lubricating film further laminated on the oxide scale,
The lubricating coating comprises a resin layer comprising a resin and wax particles dispersed in the resin,
The resin is contained in an amount of 25 to 99% by mass when the resin layer is 100% by mass, has a glass transition temperature of 30 ° C. or less, and at least one of a typical metal element and a transition metal element A method for producing a metal drawing material, which is a resin crosslinked with a compound containing a metal element and / or ions thereof.

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