JP4384641B2 - Metal materials for plastic working - Google Patents

Description

  The present invention relates to a metal material for plastic working, and in particular, to a metal material for plastic working provided with a lubricating film excellent in lubricity, seizure resistance, and corrosion resistance without containing phosphorus in the film. is there. The metal material for plastic working of the present invention includes, for example, machine parts such as bolts, nuts and springs obtained by cold working such as cold forging, cold forging, and cold rolling, steel cords, bead wires, PC ( Prestressed concrete) It is suitably used for drawn products such as steel wires.

  The metal material for plastic working is subjected to various plastic processing such as drawing, wire drawing, forging, forging, etc. depending on the application, but at that time, it is high between the processing tool and the workpiece (metal material). Pressure is applied, and seizure is likely to occur with sliding between each other. Therefore, in order to reduce friction on the surface of the workpiece and prevent seizure, a lubricating film is usually formed on the surface of the metal material.

  A typical example of the lubricating film is a composite film composed of a phosphate film and a soap layer (hereinafter sometimes referred to as “chemical conversion film”). This chemical conversion coating is a phosphate treatment on a metal material, and then a reactive soap lubrication treatment is performed to react sodium stearate, the main component of soap, with the phosphate coating. It is obtained by forming a soap layer composed of zinc stearate (metal soap) and sodium stearate (bath soap) with good adhesion. The chemical conversion treatment film is excellent in lubricity and seizure resistance, and also has good rust resistance. Therefore, the metal material provided with the chemical conversion treatment film is suitable for severe processing such as cold forging. Used for.

  However, when the above metal material is used and heat treatment is performed after cold wire drawing to produce a final product such as a bolt, phosphorus diffuses in the metal material during the heat treatment, and delayed fracture occurs. There's a problem. In addition, the formation of the phosphate film requires complicated treatment liquid management and many processes, and a large amount of sludge is generated by the chemical reaction between the treatment liquid and the material to be treated (metal material). The process requires a great deal of labor and cost.

  Then, the method of forming the lubricous film excellent in lubricity and seizure resistance without interposing a phosphate film is proposed (for example, patent documents 1-3).

  Among these, in patent document 1, after applying the aqueous solution obtained by adding sodium stearate and calcium oxide to the surface of a wire drawing material as a surface treatment, predetermined | prescribed stearate is 30-60 in total. A method of forming a lubricating film by a wire drawing method using a powdered lubricant containing a metal soap and a solid lubricant, and the balance being calcium hydroxide is described. Patent Document 2 describes a metal wire having a base layer containing potassium silicate instead of the base treatment described in Patent Document 1 described above.

  Patent Document 3 discloses that a coating is formed by immersing a raw tube in an aqueous solution containing an alkali metal salt of boric acid or an alkali metal salt of boric acid and an alkali metal salt of fatty acid, and a liquid lubricant is formed thereon. A method of applying cold drawing and performing cold drawing is described.

However, these lubricating coatings are inferior in lubricity and seizure resistance compared to the chemical conversion coating described above, and further improvements are required.
JP 2003-49188 A (Sumikin Kokura + Fuji Shaft) JP 2003-53422 A (same as above) JP 2002-192220 A (Sumikin)

  The present invention has been made in view of the above circumstances, and its purpose is to achieve lubricity and seizure resistance equivalent to or higher than those of a chemical conversion treatment film containing phosphorus, even if the film does not contain phosphorus. Another object of the present invention is to provide a metal material for plastic working provided with a lubricating film having excellent corrosion resistance.

  The metal material for plastic working of the present invention that has solved the above problems is a metal material for plastic working having a lubricating film on the surface, and the lubricating film has an improved film adhesion having a melting point of 50 to 230 ° C. It has a gist in that it contains 0.1 to 5% of components (meaning mass%, hereinafter the same), and the balance is calcium hydroxide.

  In a preferred embodiment, the film adhesion improving component is a metal salt of a carboxylic acid and / or an inorganic compound.

  The metal salt of the carboxylic acid is preferably an alkali metal salt, an alkaline earth metal salt, an aluminum salt or a transition metal salt of a carboxylic acid, or the metal salt of a fatty acid, and the metal salt of a higher saturated fatty acid ( For example, a metal salt of stearic acid is more preferable.

  The inorganic compound is preferably a sulfate.

  In a preferred embodiment, the metal material further contains 0.1 to 1% of a surfactant.

  The metal material for plastic working according to the present invention has a lubricating film with excellent adhesion to the metal material and good lubricity, seizure resistance and corrosion resistance. It is suitably used as a processing material. In addition, since the above lubricating film does not contain phosphorus, it does not cause delayed fracture due to immersion, and it can be easily formed by immersing a metal material in an aqueous solution containing a predetermined lubricant for a short time. Because it can, it is excellent in productivity.

  The present inventor has intensively studied in order to provide a metal material for plastic working having a non-phosphorus-based lubricating film having a lubricity and seizure resistance equivalent to or better than those of a chemical conversion coating film and excellent in corrosion resistance. It was. As a result, a large amount of calcium hydroxide (film forming component) and a very small amount of film adhesion improving component (low melting point material having a melting point of 50 to 230 ° C.) that binds calcium hydroxide to the surface of the metal material, The present inventors have found that the intended purpose can be achieved by forming a lubricating film containing.

  The lubricant film used in the present invention has a ratio of both controlled so that the content of calcium hydroxide is much higher than before and the content of the film adhesion-improving component is remarkably reduced. Moreover, the film adhesion improving component used in the present invention has a melting point within a predetermined range. When a metal material having the above-mentioned lubricating film is processed, the temperature of the contact portion (metal-to-metal contact) between the processing tool such as a die or a die and the metal material (work material) (generally, about 150 to 400 ° C.) As a result, a part of the film adhesion improving component is melted, and the calcium hydroxide powders are strongly bonded to each other through the melted film adhesion improving component. As a result, a coating having extremely excellent adhesion to the metal material is formed on the surface of the metal material, which is considered to improve lubricity and seizure resistance.

  In addition, although the lubricating film containing calcium hydroxide is described also in patent document 1 and patent document 2 which were mentioned above, the said film contains specific stearate in a large amount with 30 to 60% in total. In that respect, it is not limited to stearates, and the constitution is different from the lubricating film in the present invention containing only 5% of a low melting point material having a melting point of 50 to 230 ° C. at the maximum. In the above-mentioned patent documents, stearate acts as a main agent (lubricant), whereas in the present invention, even if stearate is used, it is not a main agent but an additive (film adhesion component). It is only acting as.

  In addition, the metal material provided with a lubricating film containing a large amount of stearate as in the above-mentioned patent document generates seizure, whereas if the metal material of the present invention is used, seizure does not occur and seizure resistance. It has also been clarified that (see Examples below).

  Further, in these patent documents, a base layer is provided between the lubricating film and the metal material for the purpose of improving the adhesion to the metal material. However, in the present invention, it is not necessary to form the base layer. . The lubricating film in the present invention is formed directly on the metal material without interposing an underlayer because the content of the film adhesion improving component is remarkably reduced so that the adhesion to the metal material is remarkably enhanced. can do.

  First, the lubricating film characterizing the metal material of the present invention will be described.

  As described above, the lubricating coating contains a total of 0.1 to 5% of coating adhesion improving components having a melting point of 50 to 230 ° C., and the balance: calcium hydroxide.

  Each component which comprises the said lubricating film is as follows.

(Coating adhesion improving component)
The film adhesion improving component used in the present invention has a melting point of 50 to 230 ° C. When the melting point is less than 50 ° C., the effect of inhibiting the destruction (peeling) of the film is insufficient. On the other hand, when the melting point exceeds 230 ° C., melting during processing becomes difficult, and the action of inhibiting the destruction of the film and adhesion to the film In any case, desired properties cannot be obtained (see Examples and FIG. 1 described later). A preferable range of the melting point is 100 ° C. or higher and 220 ° C. or lower.

  Furthermore, in the present invention, the content of the film adhesion improving component contained in the lubricating film is 0.1 to 5%. As shown in the examples described later, when it is out of the above range, desired lubricity cannot be obtained. If the content of the above components is less than 0.1%, the action of connecting the calcium hydroxides that are film forming components to each other is insufficient. On the other hand, if the content of the above components exceeds 5%, defects in the film are induced, This is considered to be because the film is easily broken. The content of the film adhesion improving component varies depending on the type of component used, but is generally preferably 0.5% or more and 3% or less.

  The film adhesion improving component used in the present invention is not particularly limited as long as the melting point satisfies the above range, but typically, a metal salt of a carboxylic acid or an inorganic compound is used. These may be used alone or in combination as long as the total content contained in the lubricating film satisfies the above range.

  “Carboxylic acid” includes fatty acids and naphthenic acids, which include both saturated and unsaturated fatty acids. Examples of saturated fatty acids include lower saturated fatty acids such as acetic acid (C = 2), propionic acid (C = 3), butyric acid (C = 4), and valeric acid (C = 5); palmitic acid (C = 16), Carbon such as stearic acid (C = 18), arachidic acid (C = 20), pehenic acid (C = 22), lignoceric acid (C = 24), serotic acid (C = 26), montanic acid (C = 28) A higher saturated fatty acid of several 16 or more is exemplified. Preferred saturated fatty acids are higher saturated fatty acids, and palmitic acid and stearic acid are more preferred. Examples of the unsaturated fatty acid include higher unsaturated fatty acids having 16 or more carbon atoms, such as palmitooleic acid (C = 16), oleic acid (C = 18), paxcellic acid (C = 18), linoleic acid ( C = 18), linolenic acid (C = 18), arachidonic acid (C = 20), nervonic acid (C = 22) and the like. Preferred unsaturated fatty acids are arachidonic acid and oleic acid.

  Examples of the “metal salt” in the metal salt of carboxylic acid include alkali metal salts (Li salt, Na salt, K salt, etc.), alkaline earth metal salts (Mg salt, Ca salt, Sr salt, Ba salt, etc.), Examples thereof include aluminum salts and transition metal salts (Cu salt, Zn salt, Ag salt, Ta salt, Ni salt, Co salt, Pb salt, etc.).

  Specifically, for example, acetates such as magnesium acetate tetrahydrate (melting point: about 80 ° C.), Ca stearate (melting point: about 180 ° C.), Li stearate (melting point: about 220 ° C.), Zn stearate (melting point) Stearate such as Al stearate (melting point: about 103 ° C), Mg stearate (melting point: about 132 ° C), stearic acid Ba (melting point: about 160 ° C) is preferably used. Here, sodium acetate (melting point: 320 ° C.) or sodium formate (melting point: about 245 ° C.) is not used.

  Examples of inorganic compounds (including hydrates) include sulfates, nitrates and borates. Examples of the sulfate include magnesium sulfate heptahydrate (melting point: about 67.5 ° C), zinc sulfate: heptahydrate (melting point: about 100 ° C), and examples of the nitrate include, for example, magnesium nitrate hexahydrate. (Melting point: about 89 ° C.). Of these, sulfate is preferred.

(Calcium hydroxide)
The lubricating film used in the present invention contains the above-mentioned film adhesion improving component, and the balance is calcium hydroxide.

  The average particle diameter of calcium hydroxide is not particularly limited, but considering dispersibility and the like, it is generally preferably in the range of 0.1 to 100 μm, and more preferably in the range of 0.1 to 10 μm. preferable.

  Furthermore, the lubricating film may contain other components usually contained in the lubricating film as long as the effects of the present invention are not impaired. In the present invention, for example, the following components may be further contained.

(Surfactant)
The surfactant is a component added as necessary in the process of forming the lubricating film. As will be described in detail later, the lubricating film is formed by immersing a metal material in an aqueous solution containing the above-described components (immersion method), but the film adhesion is hardly dissolved in water such as stearate. When using a property improving component, it is preferable to add a surfactant to improve dispersibility (coating property). In addition, since the surfactant is adsorbed on the surface of the metal material and has a rust preventive action, the corrosion resistance is also improved. Therefore, for example, when a water-soluble film adhesion improving component such as magnesium sulfate heptahydrate is used, it is not necessary to add a surfactant from the viewpoint of improving dispersibility, but the corrosion resistance and the like are further improved. For the purpose, it is preferable to add a surfactant.

  The content of the surfactant contained in the lubricating film varies depending on the components constituting the lubricating film and the type of surfactant used, but is generally within the range of 0.1 to 1%. preferable. If the surfactant content is less than 0.1%, the corrosion resistance is insufficient. On the other hand, adding more than 1% only saturates the corrosion resistance improving effect and only increases the cost.

  Examples of the surfactant used in the present invention include various cationic, anionic and nonionic surfactants. Examples of the cationic surfactant include quaternary ammonium salts, alkylpyridinium salts, and benzalkonium chloride. Examples of the anionic surfactant include sodium alkylbenzene sulfonate and dodecylbenzene sulfonic acid. Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenols, polyoxyethylene alkyl esters, polyoxyethylene sorbitan alkyl esters, and the like. Can be mentioned.

(Solid lubricant)
In order to further improve the lubricity by reducing the friction coefficient of the lubricating film, a solid lubricant may be contained. The kind of solid lubricant is not particularly limited, and examples thereof include paraffin wax, molybdenum disulfide, graphite, boron nitride, mica, graphite fluoride, polytetrafluoroethylene, and polyethylene. These may be used alone or in combination of two or more. These antibody lubricants are preferably contained in the lubricating film in an amount of 0.1 to 5%.

(anti-rust)
The lubricating film may contain a rust inhibitor for the purpose of further improving the corrosion resistance. The type of the rust inhibitor is not particularly limited, and those usually contained in the lubricating film can be used, and examples thereof include molybdate, vanadate, polyacrylic acid, silica, and benzotriazole.

(Other)
The lubricating film includes, for example, a reaction product (calcium carbonate or the like) of calcium hydroxide and carbon dioxide, which are main components. This is because calcium hydroxide gradually reacts with carbon dioxide in the air.

  The composition of the lubricating film is measured as follows.

  First, calcium hydroxide and a film adhesion improving component are identified by X-ray diffraction (XRD). When a solid lubricant is contained in the lubricating film, these are also identified by the XRD method. In Examples described later, CuKα rays were used as a radiation source, and an X-ray diffractometer “RINT-1500” manufactured by Rigaku Corporation was used.

  Next, the composition of the film adhesion improving component was measured by infrared spectroscopy (IR). Even when a surfactant is contained in the lubricating film, the measurement is performed by this method. In Examples described later, a JIR-100 type Fourier transform infrared spectrophotometer manufactured by JEOL Ltd. was used. The content ratio of the above components was calculated by differential thermal analysis (DTA). In Examples described later, “TG-DTA” or “TG8120” manufactured by Rigaku Corporation was used.

The adhesion amount of the lubricating film used in the present invention is preferably in the range of ^{2 to} 40 g / m ² or more. If the adhesion amount is less than 2 g / m ² , it is difficult to perform continuous wire drawing much. On the other hand, even if the adhesion amount exceeds 40 g / m ² , the above-described action by the lubricating film is saturated, leading to an increase in cost. Because it is just useless economically. The lubricating film is more preferably in the range of 4 g / m ² or more and 20 g / m ² or less.

  The lubricating film characterizing the present invention has been described above.

  The above lubricating film exhibits excellent characteristics even when directly formed on a metal material without using an underlayer (see the examples described later), but further improves the adhesion to the metal material. For the purpose of further improving the above characteristics, a general-purpose underlayer (silica-containing layer) may be interposed.

  Moreover, on the said lubricating film, the other film | membrane containing a silica etc. may be coat | covered in order to provide rust prevention property. These other films may be formed as a single layer, or two or more layers may be laminated.

  The metal material of the present invention has the above lubricating film on the surface and is used for plastic working. In this specification, “plastic working” means, for example, processing such as drawing, wire drawing, forging (including cold heading and warm heading).

  The composition of the metal material used in the present invention is not particularly limited as long as it is used for plastic working. For example, various metal materials such as steel (iron, stainless steel, chromium steel, molybdenum steel, titanium steel, etc.) and non-ferrous metal (aluminum, titanium, copper, etc.) are used. A preferred metal material is steel. These are used, for example, as a wire or a bar.

  Next, a method for forming a lubricating film used in the present invention will be described.

  The film is obtained by immersing a metal material in an aqueous solution containing the above-described components (immersion method). As a method for creating a lubricating film, there are typically a method of drawing using a powdered lubricant (drawing method) and a method of immersing in an aqueous solution containing a lubricant (dipping method). However, since the dipping method has an advantage that it is easier to form a uniform and excellent adhesive film than the wire drawing method, the dipping method is used in the present invention to form the film. According to the present invention, since a surfactant is added for the purpose of improving dispersibility according to the type of component used, there is no possibility of uneven coating.

  Specifically, first, an aqueous solution containing calcium hydroxide and the aforementioned film adhesion improving component is prepared. Depending on the type of the film adhesion improving component, a surfactant is added as necessary to obtain a dispersion. Alternatively, other components such as the above-described solid lubricant and rust preventive agent can be further added.

  In order to form a desired lubricating film using the above dispersion, calcium hydroxide is added to the dispersion in an amount of about 10 to 300 g / L (preferably about 50 to 200 g / L), and the film adhesion is improved. The ingredients are added in the range of about 0.1-14 g / L (preferably about 0.2-12 g / L).

  Note that calcium oxide may be used as a supply source of calcium hydroxide. This is because calcium hydroxide is obtained by the reaction when calcium oxide is added to water. The amount of calcium oxide added is preferably about 8 to 230 g / L (more preferably about 38 to 150 g / L). In the present invention, it is important to adjust the calcium hydroxide in the lubricating film to a predetermined range, and for that purpose, only calcium hydroxide may be used, only calcium oxide may be used, or Calcium hydroxide and calcium oxide may be used in combination.

  When a surfactant is used, it is preferable to add about 0.01 to 5 g / L (preferably about 0.1 to 1 g / L) in the aqueous solution.

  Moreover, when using solid lubricants, such as paraffin wax, it is preferable to add about 0.1-10 g / L in aqueous solution.

  Next, the metal material is immersed in an aqueous solution (or dispersion) having the above composition.

  Specific soaking conditions can be selected and adopted as appropriate for the soaking method. For example, at about 30 to 80 ° C. (more preferably 40 to 70 ° C.) for about 5 seconds or more ( More preferably, 10 seconds or more). If the immersion temperature is lower than the above range, it is necessary to strictly control the immersion temperature in a high temperature environment such as summer. On the other hand, if the immersion temperature exceeds the above range, evaporation of the aqueous solution (dispersion liquid) often occurs. As a result, the concentration of the treatment liquid is likely to fluctuate. Moreover, when immersion time is less than the said range, adhesiveness will fall. In addition, although the upper limit of immersion time is not specifically limited, Even if it soaks over about 15 minutes, the adhesive improvement effect is not acquired.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, and is implemented with appropriate modifications within a range that can meet the purpose described above and below. Any of these may be included in the technical scope of the present invention.

Example 1
(Production of test materials)
A hot-rolled wire (wire diameter: 10 mm) obtained by hot-rolling steel type SCM435 was spheroidized and annealed at 760 ° C., then pickled, descaled, and washed with water. No. 1 provided with various lubricating films was obtained by using the treatment liquid containing various components shown in Table 2 and 200 g / L of calcium hydroxide for this wire and immersing under different immersion conditions. 1 to 27 wire rods for drawing (diameter 10 mm) were obtained. The amount of coating is all about 8 g / m ² . The types and melting points of the film adhesion improving components a to h used in the examples are as shown in Table 1, cf are examples satisfying the requirements of the present invention, and a to b are melting points of the present invention. Examples below g, h, are examples where the melting point exceeds the range of the present invention.

For comparison, No. 1 provided with a chemical conversion coating comprising zinc phosphate and a soap layer. 28 wire drawing wires (diameter 10 mm) were prepared. Specifically, the hot-rolled wire obtained in the same manner as described above was pickled (15% hydrochloric acid, immersed in a pickled solution at 50 ° C. for 10 minutes), descaled, and then washed with water for 10 minutes. Next, this wire was immersed in an aqueous solution (80 ° C.) containing 90 g / L of a zinc phosphate chemical conversion treatment agent (“Palbond 181X” manufactured by Nihon Parkerizing Co., Ltd.) for 10 minutes, washed with water, and a zinc phosphate coating Formed. Next, soap treatment was performed by dipping in a treatment liquid (80 ° C.) containing 70 g / L of a soap lubricant (“Palube 235” manufactured by Nippon Parkerizing Co., Ltd.) for 5 minutes. The adhesion amount of the chemical conversion film (zinc phosphate and soap) obtained in this way is 8 g / m ² .

  Using each of the wire rods thus obtained (φ10 mm), φ9.5 mm → φ8.3 mm → φ7.45 mm → φ6.3 mm → φ5.6 mm → φ4.9 mm → φ4.2 mm → φ3.6 mm The wire was drawn step by step in order.

  Each wire after drawing was used as a test material, and the composition and content of the lubricating film were measured by the method described above, and the following characteristics were evaluated.

(Lubricity)
The wire drawing load when φ4.2 mm → φ3.6 mm was measured, and the lubricity was evaluated. Here, the case where no seizure occurred and the wire drawing load was less than 650 kgf (less than 6370 N) was defined as “excellent in lubricity”.

(Seizure resistance)
About all the test materials, the surface state (surface skin) after wire drawing was observed with the naked eye. Here, the surface having good surface and no seizure occurred was defined as “excellent in seizure resistance”.

(Evaluation of corrosion resistance)
Corrosion resistance is determined by leaving each wire after drawing in a constant temperature and humidity tester (Tabaie spec SH-221) at a temperature of 40 ° C. and a humidity of 90% for 2 weeks, and then on the surface (15.7 cm ² ) on the side surface of the wire. The area ratio of the generated rust was visually observed, measured and evaluated.

  Here, the case where the area ratio of rust was 0% was defined as “excellent in corrosion resistance”.

  These results are also shown in Table 2.

  From Table 2, it can be considered as follows.

  First, film adhesion improving components c to f having a melting point satisfying the range of the present invention were used, and the content in the lubricating film satisfied the range of the present invention. The test materials 3-6 (using component c), 8-11 (using component d), 13-19 (using component e), 22-24 (using component f) are lubricity and seizure resistance Excellent in corrosion resistance and corrosion resistance. These test materials are No. provided with a chemical conversion coating (zinc phosphate and soap). Compared with 28, it was excellent in lubricity, and no seizure was observed.

In Table 2, No. 3 to 6 show only the results of using a water-soluble magnesium sulfate · 7H ₂ O and adding a surfactant, but the same experiment was also conducted when no surfactant was added (Table 1). (Not shown in Fig. 2), it has been confirmed that the addition of a surfactant improves the corrosion resistance.

  In contrast, No. having a melting point of less than 50 ° C. Samples Nos. 1 (using component a), 2 (using component b), and No. The test materials of 25 (uses component g) and 26 (uses component h) have lubricity and seizure resistance despite the fact that the content of the components in the lubricating film is controlled within the range specified in the present invention. Decreased.

  Moreover, although melting | fusing point is satisfying the range of this invention, it is No. with little content in a lubricating film. The test material of No. 7 (using component d) was deteriorated in lubricity and seizure resistance.

  Moreover, although melting | fusing point is satisfying the range of this invention, No. with much content in a lubricating film. 12 (use component d), No. 12 20 to 21 (using component e) had good lubricity but decreased seizure resistance. In addition, No. 20 and no. No. 21 is different only in the presence or absence of addition of a surfactant. When a surfactant is added as in No. 20, no surfactant is added. It can be seen that the corrosion resistance is improved compared to 21. It has been confirmed by experiments that the corrosion resistance improving effect by the addition of the surfactant is recognized regardless of the type and content of the film adhesion improving component.

  No. No. 27 is a comparative example that does not contain any component for improving film adhesion, and all the characteristics deteriorated.

Example 2
In order to investigate the influence of the melting point of the film adhesion improving component on the seizure resistance, some of the test materials (Nos. 2, 4, 9, 14, 22, 25, 26) of Example 1 described above are described below. The sliding test was conducted. No. 2 is a comparative example using a component b having a melting point of less than 50 ° C., No. 2; Nos. 25 and 26 are comparisons using components g and h whose melting points exceed 230 ° C. Nos. 4, 9, 14, and 22 are examples of the present invention using components c, d, e, and f whose melting points satisfy the scope of the present invention, and each contains 2.4% of each component in the film. ing.

  First, a test piece (φ10 mm, length 50 mm) for a sliding test is prepared. Next, a reciprocating sliding test (load 1 kg, sliding distance 2 cm) was performed using a surface property tester (“Drybogear HEIDON-140 DR” manufactured by Shinto Kagaku Co., Ltd.). The number of reciprocating slides (limit sliding number) until increasing to 0.25 was measured.

  Here, those having a limit sliding number of 10,000 or more were defined as “excellent in seizure resistance”.

  The results are shown in Table 3, and FIG. 1 is a graph showing the relationship between the melting point of the film adhesion improving component and the limit number of sliding times (seizure resistance).

  From Table 3 and FIG. 1, in order to ensure excellent seizure resistance according to the present invention, the melting point of the film adhesion improving component is extremely important, and the melting point is outside the range of 50 to 230 ° C. It turns out that an effect is not acquired.

It is a graph which shows the relationship between melting | fusing point of a film | membrane adhesion improving component, and the limit frequency | count of sliding (seizure resistance).

Claims (6)

A metal material for plastic working having a lubricating film on the surface,
The lubricating film contains 0.1 to 5% (meaning mass%, hereinafter the same) of a film adhesion improving component having a melting point of 50 to 230 ° C., and the balance is calcium hydroxide. Metal material for plastic working.   The metal material for plastic working according to claim 1, wherein the film adhesion improving component is a metal salt and / or an inorganic compound of carboxylic acid.   The metal material for plastic working according to claim 2, wherein the metal salt of carboxylic acid is an alkali metal salt, alkaline earth metal salt, aluminum salt, or transition metal salt of carboxylic acid.   The metal material for plastic working according to claim 2 or 3, wherein the metal salt of carboxylic acid is a metal salt of fatty acid.   The metal material for plastic working according to any one of claims 1 to 4, wherein the inorganic compound is a sulfate.   Furthermore, the metal material for plastic working in any one of Claims 1-5 containing 0.1 to 1% of surfactant.

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