JPH04514B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] This invention is applied as a pre-treatment when manufacturing various parts of automobiles, construction machines, agricultural machinery, etc., parts of various tools, various parts of electrical equipment, etc. by warm forging. This invention relates to a lubrication treatment method. [Prior art] There are three known forging methods for forging metal materials: cold, warm, and hot, and the advantages and disadvantages of each have been reported in many documents. However, for machining that requires precision, warm forging is said to be the most superior in terms of quality and energy. When carrying out this warm forging, the surface of the metal material is lubricated as a pretreatment, but in the past, the metal material was immersed in an aqueous or oil dispersion of a solid lubricant. This metal material is coated with an aqueous dispersion or an oil dispersion of the solid lubricant by spraying or the like. [Problems to be solved by the invention] However, in the above conventional lubrication treatment method,
If the strength of the lubricating film formed on the surface of the metal material is insufficient, or if the solid lubricant is not sufficiently introduced to the new surface during warm forging, it may be difficult to obtain satisfactory results when forming with a small degree of processing. Even if it is possible, if the degree of processing increases, galling and seizure of the mold will occur, and
Since the life of the mold was shortened, it could not be said that this was a completely satisfactory lubrication method. The present invention was devised in view of these points of view, and exhibits excellent lubrication performance in the warm range of 300 to 800°C, and has excellent followability to new surfaces generated during processing, preventing mold galling and burning. The present invention provides a lubrication treatment method for warm forging of metal materials that can form a lubricant film that hardly causes sticking. [Means for Solving the Problems] That is, the present invention provides, prior to warm forging of a metal material, applying a water-soluble material having a polar group that can be ionically dissociated in an aqueous solution to the surface of the metal material by electrodeposition. This is a lubrication treatment method for warm forging of metal materials, which forms a lubricating film containing a water-dispersible electrodeposited resin and a lubricating solid powder. The metal material to be lubricated by the method of the present invention is not particularly limited as long as it can be subjected to warm forging and can be coated by electrocoating. Structural steel, stainless steel, titanium, various alloys, etc. can be mentioned. In the method of the present invention, prior to warm forging of the metal material, a water-soluble or water-dispersible electrodeposited resin having a polar group that can be ionically dissociated in an aqueous solution and a lubricating solid powder are contained on the surface of the metal material. Forms a lubricating film. The water-soluble or water-dispersible electrodeposited resin having a polar group that is ionically dissociable in an aqueous solution used in the method of the present invention has a polar group such as a carboxyl group, an amino group, an amide group, a sulfonate group, etc. Any resin may be used as long as it becomes water-soluble or water-dispersible when neutralized with an acid or base and exhibits electrophoretic properties. Examples of such electrodeposition resin include drying oil, acrylic resin, alkyd resin, acrylic alkyd resin, epoxy resin, acrylic epoxy resin, melamine resin, acrylic melamine resin, phenol resin, Acrylic phenol resin, acrylic urea resin, acrylic modified polyester resin, benzoguanamine resin,
Examples include anionically modified or cationically modified amide resins, ester resins, and urethane resins, and both anionic and cationic types can be used. These electrodeposited resins can be used alone or in a mixture of two or more of the same ionic type. In addition, mineral acids such as hydrochloric acid or organic acids such as acetic acid can be used as acids to make this electrodeposited resin water-soluble or water-dispersible, and bases include alkalis, ammonia, and ethylamine. , dimethylaminopropylamine, monoethalamine, dimethylmorpholine, and other organic amines. Furthermore, in the lubricant used in the method of the present invention,
The lubricating solid powder may be of any kind as long as it slides in a layered manner under the operating temperature and plastic pressure on the lubricated surface, or that melts at the operating temperature and exhibits lubricating performance. Examples of the crystal structure include those belonging to a close-packed hexagonal system and those having a layered structure. Specific examples of this lubricating solid powder include graphite, fluorinated graphite,
Examples include boron nitride, mica, talc, tungsten disulfide, glass, waxite, molybdenum disulfide, titanium oxide, Teflon, inorganic phosphates, zinc sulfide, etc., and only one of these can be used alone. , it can also be used as a mixture of two or more types. Preferred as these lubricating solid powders are graphite or a mixture of one or more of graphite and other lubricating solid powders. The above-mentioned lubricating solid powder is preferably used as a resin-coated lubricating solid powder whose surface is coated with a resin, and more preferably, it is used as a resin-coated lubricating solid powder that coats the surface of this lubricating solid powder with ions in an aqueous solution. By using a water-soluble or water-dispersible resin having a dissociable polar group, preferably a resin consisting of a copolymer of at least one of acrylic acid, methacrylic acid, areic acid, itaconic acid, acrylamide, etc. and a vinyl monomer. be. Methods for coating the surface of the above-mentioned lubricating solid powder with resin include the conventionally known interfacial polymerization method, in situ polymerization method, in-liquid curing coating method, phase separation method from an aqueous solution, and phase separation method from an organic solution. method, submerged drying method, melting dispersion cooling method, inclusion exchange method, powder bed method,
There are air suspension coating methods, spray drying methods, vacuum evaporation methods, electrostatic coalescence methods, etc., but preferably after adsorbing a metal salt or organic substance that can impart an electric charge to the surface of a lubricating solid powder, this metal This is a method in which the lubricating solid powder is brought into contact with a resin solution or dispersion containing one or more types of thermoplastic resin latex having a charge opposite to that of a salt or an organic substance, and more preferably a vinyl monomer is added to the surface of the lubricating solid powder. This is a method of graft polymerizing. Graft polymerization of the vinyl monomer onto the surface of the above-mentioned lubricating solid powder can be carried out by various polymerization methods such as bulk polymerization method and solution polymerization method in the presence of a radical polymerization initiator. Particularly preferred is a method in which a lubricating solid powder and a vinyl monomer are subjected to suspension polymerization in an aqueous medium in the presence of a compound that generates sulfite ions, and water is generally used as the medium for suspension polymerization. Other aqueous media can be used, such as, but not limited to, a mixture of water and methanol. In addition, as a polymerization initiator in suspension polymerization, a compound that generates hydrogen sulfite ions in an aqueous medium, such as the injection of sulfur dioxide gas, an aqueous solution of sulfite, or a sulfite such as sodium hydrogen sulfite or ammonium hydrogen sulfite; Persulfates such as potassium persulfate, sodium persulfate and ammonium persulfate can be used alone or in combination. A preferred embodiment of the method for graft polymerizing the vinyl monomer onto the surface of this lubricating solid powder is to treat the lubricating solid powder with a surfactant in advance to selectively polymerize the surface of the lubricating solid powder. By forming a molecular layer of a surfactant that acts as a field, and then polymerizing a vinyl monomer on the surface of the lubricating solid powder in the liquid dispersion medium, all or most of the surface of the lubricating solid powder is made of vinyl. It is better to coat it with a polymer. contacting the lubricating solid powder in the liquid dispersion medium;
As the surfactant that forms a molecular layer on the surface that serves as a selective polymerization site, most of the surfactants commonly used can be used. In addition, examples of vinyl monomers that polymerize on the surface of the lubricating solid powder to coat the surface of the lubricating solid powder include acrylic acid, methacrylic acid, α-chloroacrylic acid, itaconic acid, maleic anhydride,
Ionically dissociable vinyl monomers such as unsaturated carboxylic acids such as maleic acid and fumaric acid, vinyl halides such as vinyl chloride and vinyl fluoride, styrene compounds such as styrene and α-methylstyrene, and acetic acid. Nonionically dissociable vinyl monomers such as vinyl, aliphatic vinyl esters such as vinyl propionate, and unsaturated carboxylic acid esters such as methyl acrylate, methyl methacrylate, glycidyl methacrylate, and lauryl methacrylate. water-soluble or water-dispersible resin, preferably having a polar group that can be ionically dissociated in an aqueous solution;
For example, acrylic acid, methacrylic acid, maleic acid,
Examples include vinyl monomers that produce resins consisting of copolymers of at least one of itaconic acid, acrylamide, etc., and vinyl monomers.
When coating the surface of this lubricating solid powder with resin by graft polymerization, the amount of resin is 0.1 to 75% when the coating resin is a water-soluble or water-dispersible resin having a polar group that can be ionically dissociated in an aqueous solution. weight%,
Preferably it is 0.5 to 50% by weight, and when the coating resin is not the water-soluble or water-dispersible resin mentioned above, it is usually
0.1-30% by weight, preferably 0.5-20% by weight. In the present invention, the blending ratio of the electrocoated resin and the lubricating solid powder is determined by the types of the electrocoated resin and lubricating solid powder used, whether or not the lubricating solid powder is coated with a resin, and whether or not the lubricating solid powder is coated with a resin. Although it varies depending on the type etc., 10 to 300 parts by weight of the electrodeposited resin is preferably added to 100 parts by weight of the lubricating solid powder.
20 to 200 parts by weight. The amount of this electrodeposition resin used is
If it is less than 10 parts by weight, the strength of the lubricating film formed on the surface of the metal material will be insufficient and smooth warm forging will not be possible, and if it is more than 300 parts by weight, the lubricating film formed on the surface of the metal material will be insufficient. The lubricating properties of the resin are dominated by the resin, reducing the characteristics of using lubricating solid powders. In addition, when a water-soluble or water-decomposable resin having a polar group that can be ionically dissociated in an aqueous solution is used as the coating resin for the lubricating solid powder, and the amount of the resin is in the range of 10 to 75% by weight, Since this coating resin also acts as an electrodeposition resin, there is no need to use the electrodeposition resin separately. In the present invention, the electrodeposition coating method for forming a lubricating film containing the electrodeposition resin and the lubricating solid powder on the surface of the metal material may be any conventionally commonly used method. An electrodeposition solution is prepared by dissolving or dispersing the solid powder in water using a suitable acid or base and, if necessary, hexavalent chromate, and the electrodeposition resin dissociates into anions in the aqueous solution. When dissociating into cations, the metal material side is used as an anode, and when dissociating into cations, the metal material side is used as a cathode. It should be noted that before the metal material to be processed is subjected to electrodeposition coating, it is necessary to remove scale and degrease the metal material, and for this purpose various commonly used cleaning methods such as pickling, pickling, etc. Trichlorethylene vapor degreasing cleaning, ultrasonic cleaning, blast cleaning, etc. can be employed. The conditions for this electrodeposition coating are that the solid content concentration in the electrodeposition liquid is usually 3 to 50% by weight, preferably 5 to 30% by weight, and the pH of the electrodeposition liquid is preferably anionic. is 7.5 to 8.5, preferably 5.5 to 6.9 in the case of cationic type, the electrodeposition liquid temperature is 10 to 90°C, preferably 30 to 80°C, and the voltage is
The voltage is 50 to 300V, preferably 70 to 250V, and the current application time is 5 to 240 seconds, preferably 10 to 180 seconds. The thickness of the lubricating film formed on the surface of the metal material can be adjusted by appropriately changing the solid content concentration, electrodeposition liquid temperature, voltage, current application time, etc. of the electrodeposition liquid. The thickness of the lubricating film formed on the surface of this metal material is usually 5 to 300 μm, preferably 10 to 300 μm.
A range of 150 μm is preferable. [Function] According to the method of the present invention, since a lubricating film containing an electrodeposited resin and a lubricating solid powder is formed on the surface of a metal material by electrodeposition coating, the surface of the metal material cannot be electrodeposited. It is thought that the resin is directly and strongly chemically bonded, and that the lubricating solid powder used in combination is incorporated into this electrodeposited resin, forming an extremely strong lubricating film on the surface of the metal material. [Example] Hereinafter, the method of the present invention will be specifically explained based on Examples and Comparative Examples. Example 1 100 parts by weight of graphite powder with an average particle size of about 2 μm was added to 100 parts by weight of water.
50 parts by weight of an acrylic monomer and 6 wt% sulfite aqueous solution, which is suspended in 1 part by weight and mixed with butyl acrylate and acrylic acid at a weight ratio of 3:1.
80 parts by weight was added, reacted with stirring at 60°C for 5 hours, filtered, washed with water, and dried to obtain resin-coated graphite powder 145 with a resin content of 31% by weight, in which the surface of the graphite was coated with butyl acrylate/acrylic acid copolymer. Parts by weight were obtained. Next, 100 parts by weight of the obtained resin-coated graphite powder was suspended in 1000 parts by weight of water, and the pH was adjusted to 7.5 with aqueous ammonia to prepare an electrodeposition liquid. Using this electrodeposition solution, electrodeposition is performed using a metal material (material S45C) as an anode and a stainless steel plate (SUS304) as a workpiece with a diameter of 30 mm x height of 45 mm as a cathode, and a film is applied to the surface of the metal material. A lubricating film with a thickness of 60 μm was formed.
The graphite content of this lubricating coating was 68% by weight. After lubricating the metal material of the workpiece in this way, the workpiece is heated to 550°C and 700°C by high frequency.
heated to 145ton and 200ton press respectively.
Table 1 shows the maximum diameter of the workpiece when 70 tons is applied. There was no breakage of the lubricating film on the workpiece or seizure of the mold, and warm forging using a press could be performed extremely smoothly. Example 2 100 parts by weight of graphite powder with an average particle size of about 2 μm was mixed with 100 parts by weight of water.
5 parts by weight of methyl methacrylate monomer and 20 parts by weight of 6 wt% sulfite aqueous solution were added thereto, and the mixture was reacted with stirring at 60°C for 3 hours.
After filtering, washing with water, and drying, 105 parts by weight of resin-coated graphite powder with a resin amount of 4.7% by weight, in which the surface of the graphite was coated with methyl methacrylate resin, was obtained. Next, 50 parts by weight of the obtained resin-coated graphite powder and 100 parts by weight of acrylic anionic electrodeposited resin (trade name: Aron S4020, manufactured by Toagosei Co., Ltd.) were suspended in 1000 parts by weight of water, and aqueous ammonia was added. The pH was adjusted to 7.5 and used as an electrodeposition solution. Using this electrodeposition liquid, electrodeposition coating was performed in the same manner as in Example 1, and a film thickness of 40 μm was applied to the surface of the metal material.
A lubricating film of m was formed. The graphite content of this lubricating coating was 63% by weight. The workpiece thus lubricated was subjected to press working under the same conditions as in Example 1 above. Table 1 shows the maximum diameter of the workpiece after processing. There was no breakage of the lubricating film on the workpiece or mold seizure, and warm forging using a press could be performed extremely smoothly. Example 3 50 parts by weight of graphite powder with an average particle size of about 2 μm and 100 parts by weight of the acrylic anionic electrodeposited resin used in Example 2
parts by weight were suspended in 1000 parts by weight of water, and the pH was adjusted to 7.5 with aqueous ammonia to prepare an electrodeposition solution. Electrodeposition coating was performed using this electrodeposition liquid in the same manner as in Example 1 to form a lubricating film with a thickness of 30 μm on the surface of the metal material. The graphite content of this lubricating coating was 60% by weight. The workpiece thus lubricated was subjected to press working under the same conditions as in Example 1 above. Table 1 shows the maximum diameter of the workpiece after processing. There was no breakage of the lubricating film on the workpiece or mold seizure, and warm forging using a press could be performed extremely smoothly. Example 4 The same procedure as in Example 3 was carried out using 50 parts by weight of boron nitride powder with an average particle size of about 6 μm and 100 parts by weight of alkyd resin (trade name: Watersol S-136, manufactured by Dainippon Ink Co., Ltd.). It was used as an electrodeposition liquid. Electrodeposition coating was performed using this electrodeposition liquid in the same manner as in Example 1 to form a lubricating film with a thickness of 15 μm on the surface of the metal material.
The boron nitride content of this lubricating coating was 50% by weight. The workpiece thus lubricated was subjected to press working under the same conditions as in Example 1 above. Table 1 shows the maximum diameter of the workpiece after processing. There was no breakage of the lubricating film on the workpiece or mold seizure, and warm forging using a press could be performed extremely smoothly. Comparative Example 1 When the workpiece used in Example 1 was immersed in the electrodeposition liquid prepared in Example 1, the adhesion was insufficient, so the electrodeposition liquid of Example 1 was air-sprayed into Example 1. It is applied to the workpiece and a film thickness of 60μ is applied to the surface of the workpiece.
A lubricating film of m was formed, and press molding was performed under the same conditions as in Example 1. Table 1 shows the maximum diameter of the workpiece after processing. At this time, some breakage of the lubricating film on the workpiece occurred, and seizure to the mold was observed. Comparative Example 2 The workpiece used in Example 1 was immersed in the electrodeposition liquid prepared in Example 2 to form a lubricating film with a thickness of 40 μm on the surface, and press molded under the same conditions as Example 1. I went there. Table 1 shows the maximum diameter of the workpiece after processing. At this time, breakage of the lubricating film on the workpiece occurred, and seizure to the mold was observed. Comparative Example 3 The workpiece used in Example 1 was immersed in the electrodeposition liquid prepared in Example 3 to form a lubricating film with a thickness of 30 μm on the surface, and press molded under the same conditions as Example 1. I went there. Table 1 shows the maximum diameter of the workpiece after processing. At this time, breakage of the lubricating film on the workpiece occurred, and seizure to the mold was observed. Comparative Example 4 The workpiece used in Example 1 was immersed in the electrodeposition liquid prepared in Example 4 to form a lubricating film with a thickness of 15 μm on the surface, and press molded under the same conditions as Example 1. I went there. Table 1 shows the maximum diameter of the workpiece after processing. At this time, breakage of the lubricating film on the workpiece occurred, and seizure to the mold was observed.

[Table] As is clear from the results in Table 1 above, the amount of deformation of the workpiece in each example was much larger than in each comparative example, and there were also problems such as breakage of the lubricant film and metallurgy. No sticking to the mold occurs. [Effect of the invention] According to the lubrication treatment method for warm forging of metal materials of the present invention, excellent lubrication performance is exhibited in the warm range of 300 to 800°C, and formability is increased and new surfaces generated during processing are prevented. It can form a lubricating film that has excellent followability and hardly causes galling or seizure of the mold, making it easier to perform warm forging of metal materials and improving the life of the mold. can do.

Claims (1)

[Claims] 1. Prior to warm forging of a metal material, a water-soluble or water-dispersible electrodeposition resin having a polar group that can be ionically dissociated in an aqueous solution is applied to the surface of the metal material by electrodeposition coating. 1. A lubrication treatment method for warm forging of metal materials, the method comprising forming a lubricating film containing a lubricating solid powder and a lubricating solid powder. 2. The lubrication treatment method for warm forging of metal materials according to claim 1, wherein a resin-coated lubricant solid powder whose surface is coated with a resin is used as the lubricant solid powder. 3. Lubrication for warm forging of metal materials according to claim 2, wherein the coating resin that coats the surface of the lubricating solid powder is a water-soluble or water-dispersible resin having a polar group that can be ionically dissociated in an aqueous solution. Processing method.