JP6200283B2 - Lubricants for warm and hot forging - Google Patents

Description

  The invention disclosed herein relates to lubricants for warm and hot forging. More specifically, the present invention relates to a lubricant for warm and hot forging that does not substantially contain graphite.

  Warm and hot forging lubricants are used for the purpose of suppressing metal wear and smooth plastic deformation of metal materials when plastically deforming metal materials (workpieces) using molds. Is done.

  As disclosed in the following Patent Document 1 and Patent Document 2, a lubricant containing graphite has been used as a warm and hot forging lubricant.

  The lubricant containing graphite is excellent in heat resistance stability and lubricity, but on the other hand, it is difficult to uniformly apply to the mold surface, and graphite powder is scattered, which is undesirable for the hygienic working environment. There was a problem that graphite powder was deposited on the surface. In view of this problem, lubricants for warm and hot forging that do not contain graphite have been developed. The warm and hot forging lubricants that do not contain graphite are particularly characterized in that the working environment can be improved.

As a test method for evaluating warm and hot forging lubricants, a spike test is generally known. The spike test is classified as forward extrusion.
For example, if a high spike can be formed while keeping the maximum indentation load low, it can be evaluated that the metal material and the mold are slippery during processing. Further, for example, when the ejector load is low, it can be evaluated that there is no (or less) seizure between the molded metal mold and the molded metal material, and the remaining coating amount is large.

  The following Patent Document 3 describes an example of a spike test.

JP 62-50396 A JP 2009-91444 A JP-A-5-7969

  As described above, warm and hot forging lubricants that do not contain graphite have been developed. However, the conventional lubricant is inferior in lubricating performance as compared with a lubricant containing graphite. For this reason, in drawing work represented by forging of constant velocity joint outer races that require high lubricity, switching from a lubricant containing graphite to a lubricant for warm and hot forging that does not contain graphite. It was a situation that did not progress.

  As a result of extensive research, the inventor of the present application has found that a specific compound in which two aromatic rings having two carboxyl groups located at ortho positions with each other are effective in improving lubricity, and disclosed herein. Completed warm and hot forging lubricants.

  The warm and hot forging lubricant disclosed in this application exhibits higher lubricity than conventional warm and hot forging lubricants that do not contain graphite. Further, the lubricant for warm and hot forging disclosed in the present application is a lubricant that can be substituted for a lubricant containing graphite in difficult processing such as drawing processing represented by forging processing of a constant velocity joint outer race. it was thought.

  Accordingly, it is an object of the present application to provide a lubricant for warm and hot forging that is excellent in lubricity.

(First invention)
The first invention of the present application for solving the above-described problems is as follows.
It is a lubricant for warm and hot forging containing one or more selected from compounds represented by the following general formulas 1 to 2 and substantially free of graphite.
(In the above general formula 1, A ₁ is an alkali metal atom, an alkaline earth metal atom, ammonia, or an organic amine.)
(In the above general formula 2, A ₂ is an alkali metal atom, an alkaline earth metal atom, ammonia, or an organic amine. R is an oxygen atom (O) or a carbonyl group (—CO—).)

(Second invention)
The second invention of the present application for solving the above-described problems is as follows.
Further, the present invention is warm and hot as described in the first invention, which shows one or two or more kinds selected from a synthetic polymer and a salt thereof that show water solubility or good water dispersibility, and contain olefin as a monomer. Forging lubricant.

  The warm and hot forging lubricant disclosed in the present application is excellent in lubricity. It is considered that the lubricant for warm and hot forging disclosed in the present application has a good effect even in difficult processing such as drawing processing represented by forging processing of a constant velocity joint outer race.

  Hereinafter, embodiments of the invention disclosed in the present application will be described including the best mode.

[Composition etc.]
This application discloses a lubricant for warm and hot forging containing one or more selected from the compounds represented by the above general formulas 1 to 2 and substantially free of graphite.

  The compounds represented by the above chemical formulas 1 to 2 can also be obtained by hydrolyzing a compound which is an acid anhydride to form a salt. For the hydrolysis and salt formation, it is preferable to use an alkali such as sodium hydroxide, potassium hydroxide or lithium hydroxide, but it is not limited thereto.

  Examples of the alkali metal atom include sodium, potassium, lithium and the like.

  Examples of the alkaline earth metal atom include calcium, magnesium, barium and the like.

  Examples of the organic amine include alkylamine and alkanolamine. Examples of the alkylamine include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, propylamine, dipropylamine, tripropylamine, butylamine, dibutylamine, and tributylamine. Examples of the alkanolamine include monomethanolamine, dimethanolamine, trimethanolamine, monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, tripropanolamine, butanolamine, dibutanolamine, and tributanol. There are amines.

  From the viewpoint of improving lubricity, the warm and hot forging lubricant disclosed in the present application preferably contains one or more selected from the compounds represented by Formula 2 above.

In the above general formulas 1 to 2, A ₁ and / or A ₂ are preferably alkali metal atoms. From the viewpoint of improving lubricity, in the above general formulas 1 to 2, it is more preferable that A ₁ and / or A ₂ is sodium.

  From the viewpoint of improving lubricity, in the above general formula 2, R is preferably a carbonyl group.

  In the lubricant for warm and hot forging disclosed in the present application, the content of one or more selected from the compounds represented by the above general formulas 1 to 2 is not particularly limited. It can be appropriately selected according to the type of lubricant for warm and hot forging. To give an example, it may be 0.1 to 40% by mass, or 5 to 15% by mass.

  The warm and hot forging lubricant disclosed in the present application is usually further mixed with water and then applied to the mold. The content at the time of the use of the 1 type (s) or 2 or more types chosen from the compound represented by the said General formula 1-Formula 2 can be suitably determined according to the conditions of forging. For example, the content may be 0.05 to 20% by mass, or 0.3 to 15% by mass.

  The warm and hot forging lubricant disclosed in the present application is, from the viewpoint of improving lubricity, for example, one kind selected from a synthetic polymer and a salt thereof containing olefin as a monomer, such as acrylic acid or maleic acid, or the like. It is preferable to further contain two or more kinds. The said synthetic polymer and its salt refer to what shows water solubility or favorable water dispersibility.

  In the lubricant for warm and hot forging disclosed in the present application, the content of one or more selected from synthetic polymers containing the olefin as a monomer and salts thereof is not particularly limited. It can be appropriately selected according to the type of lubricant for warm and hot forging. To give an example, it may be 0.1 to 40% by mass, or 1 to 15% by mass.

  The content at the time of using 1 type, or 2 or more types selected from a synthetic polymer containing the olefin as a monomer and a salt thereof can be appropriately determined according to forging conditions. For example, the content may be 0.05 to 20% by mass, or 0.1 to 15% by mass.

  Examples of the synthetic polymer containing the olefin as a monomer include polyacrylic acid, polystyrene sulfonic acid, polymethacrylic acid, polyalkenyl succinic acid, polyvinyl alcohol, isobutylene-maleic anhydride copolymer, styrene-maleic anhydride copolymer. Examples thereof include a polymer, a methacrylic acid-maleic anhydride copolymer, and a styrene sulfonic acid-maleic anhydride copolymer. Polyacrylic acid and isobutylene-maleic anhydride copolymer are preferable. Examples of the polymer salt include a sodium salt and a potassium salt.

  In the present application, polysaccharides such as cellulose, polysaccharide derivatives such as carboxymethyl cellulose, polyethylene glycol, polypropylene glycol, and polyethylene glycol-polypropylene glycol copolymers are not included in the synthetic polymer contained from the viewpoint of improving the lubricity. These are optional components.

  The warm and hot forging lubricant disclosed in the present application may appropriately contain any component in addition to the above-described components. Examples of the optional component include alkalis such as sodium hydroxide, potassium hydroxide, and lithium hydroxide, diphenic acid, trimellitic acid, pyromellitic acid, and hexahydrophthalic acid. Carboxylic acids having two or more carboxyl groups that do not correspond to the compounds, and when possible, acid anhydrides thereof, polysaccharides such as cellulose, polysaccharide derivatives such as carboxymethylcellulose, polyethylene glycol, polypropylene glycol, polyethylene glycol-polypropylene glycol copolymer And preservatives such as sorbate, dyes, fragrances, solid lubricants, waxes, surfactants, antifoaming agents, pH adjusters, rust inhibitors, extreme pressure additives, and the like.

  The warm and hot forging lubricant disclosed in the present application does not contain graphite, or even if it is contained, the amount allowed as an impurity.

  Note that the lubricant for warm and hot forging disclosed in the present application may not contain an alkali metal salt of phosphoric acid. Examples of the alkali metal salt of phosphoric acid include those described in Patent Document 2 above.

  The warm and hot forging lubricant disclosed in the present application may be mixed with water and then applied to a mold or a workpiece. Before mixing (during storage and distribution), the dosage form of the lubricant for warm and hot forging disclosed in the present application is not particularly limited. For example, the dosage form is preferably liquid. On the other hand, the dosage form can be made into a solid such as a powder or a granule from which water has been substantially removed, thereby reducing the capacity during transportation and reducing the transportation cost.

[Preferred forging conditions, etc.]
The lubricant for warm and hot forging disclosed in the present application is preferably used in forging in which the temperature of the workpiece is in the range of 800 to 1250 ° C. Moreover, it is preferable to use by the forging which makes the temperature of a metal mold | die into the range of 70-400 degreeC.

  The lubricant for warm and hot forging disclosed in the present application can be used in various processing methods. Since the lubricant for warm and hot forging disclosed in the present application exhibits good lubricity, it can be used in difficult processing such as drawing processing represented by forging processing of a constant velocity joint outer race. In addition, for example, it can be used in forward extrusion, backward extrusion, front / rear extrusion, upsetting, gear molding, crankshaft molding, and the like.

  The lubricant for warm and hot forging disclosed in the present application can be applied to a mold and a workpiece by an appropriate method in consideration of the material, shape, temperature, and the like of the mold and the workpiece. For example, there are spray application using air spray and the like, brush application, immersion and the like.

  The lubricant for warm and hot forging disclosed in the present application is preferably used for warm and hot forging of workpieces based on iron, stainless steel, titanium, and / or brass.

  The lubricant for warm and hot forging disclosed in the present application is preferably adjusted to pH 7 to 12, particularly preferably pH 8 to 11, and then applied to a mold or a workpiece.

  As described above, the present application also discloses a warm and hot forging method excellent in lubricity. In the method, the configuration described in the embodiment for carrying out the invention can be appropriately adopted.

  Examples are described below. The technical scope of the invention disclosed in the present application is not limited to the following examples.

(Preparation of lubricant)
Each lubricant according to Examples 1 to 9 and Comparative Examples 1 to 5 described in Table 1 shown later was manufactured in a liquid dosage form by a well-known method.

  In Table 1, the unit of the numerical value indicating the content of each component is mass%. Ingredients that are acid anhydrides undergo hydrolysis to have a carboxyl group and can form salts with formulated sodium, potassium, or lithium. Only Comparative Example 5 does not contain an acid anhydride.

  Examples 1 and 6 are examples containing the compound represented by the above general formula 1. Example 2, Example 6 and Example 7 are examples containing the compound represented by the above general formula 2 in which R is an oxygen atom. Examples 3 to 5 and Examples 7 to 9 are examples containing the compound represented by the above general formula 2 in which R is a carbonyl group.

The structural formula of pyromellitic anhydride used in Comparative Example 1 is shown in Chemical Formula 3 below.

The structural formula of hexahydrophthalic anhydride used in Comparative Example 2 is shown in Chemical Formula 4 below.

The structural formula of diphenic anhydride used in Comparative Example 3 is shown in Chemical Formula 5 below.

The structural formula of 3,3 ′, 4,4′-diphenylsulfonetetracarboxylic dianhydride used in Comparative Example 4 is shown in Chemical Formula 6 below.

[Spike test]
The spike test disclosed in the above-mentioned Patent Document 3 was performed.

-Equipment used-
The press machine used was a 200t crank press machine (manufactured by Komatsu Industries). The stroke length was 250 mm, the number of strokes was 25 spm, and the die gap was 3 mm.
The test piece (workpiece) was made of S45C material and φ25 mm × 30 mm in size.
The mold was made of SKD61 and polished with # 1000 sandpaper before the spike test.
The material of the test piece and the mold follows the composition described in “JIS Handbook 2005”.

-Spike test 1-
The mold was heated to 200 ° C. and the test piece was heated to 900 ° C. Each lubricant according to Examples 1 to 9 and Comparative Examples 1 to 5 was further diluted 10 times with water, and 2 ml was applied to the mold by air spray in each test. Then, the test piece was processed. The maximum indentation load at the time of test piece processing was measured with a load cell for indentation load measurement.

  About each Example and each comparative example, the test was done 5 times. “Spike height (mm)” and “maximum indentation load (tonf)” used average values of test results for evaluation.

  The ratio of spike height (mm) to maximum indentation load (tonf) “spike height / maximum indentation load (mm / tonf)” was used as an evaluation index of lubricity of the lubricant. In the “Lubricity Evaluation” column, “○” indicates that the ratio is equal to or exceeds that of Comparative Example 5 using graphite, and “X” indicates that the ratio is smaller than graphite.

  Table 1 shows the spike height, the maximum indentation load, the ratio thereof, and the lubricity evaluation of the lubricant according to each example.

[Table 1]

-Spike test 2-
The test piece was tested under the same conditions as the spike test 1 except that the test piece was heated to 1100 ° C.

  As a result, both the examples and the comparative examples had the same tendency as the spike test 1 described above, and Examples 1 to 9 showed lubricity equivalent to or exceeding that of Comparative Example 5 which is a lubricant containing graphite. Comparative Examples 1-4 obtained a lubricity evaluation inferior to that of Comparative Example 5, which is a lubricant containing graphite.

-Test results-
The lubricants according to Examples 1 to 9 all showed lubricity equivalent to or exceeding that of Comparative Example 5 containing graphite. In Examples 1 to 9, a common chemical structure was found that “two aromatic rings having two carboxyl groups located in the ortho positions relative to each other are bonded”.

  The lubricant containing graphite as in Comparative Example 5 shows good lubricity even in difficult processing such as drawing processing represented by forging processing of constant velocity joint outer races. Since the lubricants according to Examples 1 to 9 have good lubricity under the same test conditions as Comparative Example 5, it is considered that the lubricants can be preferably applied to actual difficult machining.

  On the other hand, the lubricants according to Comparative Examples 1 to 4 all had a significantly lower lubricity evaluation than Comparative Example 5.

  From the above results, the lubricant for warm and hot forging containing one or more selected from the compounds represented by the above general formulas 1 to 2 and substantially not containing graphite, It was thought that good lubricity was exhibited. The warm and hot forging lubricants were considered to be replaceable with lubricants containing graphite.

  From the results of Examples 1 to 3 and Examples 6 to 7, it is preferable that the lubricant contains one or more selected from the compounds represented by Formula 2 above. In Chemical Formula 2, it was considered that it was more preferable to contain a compound in which R is a carbonyl group in the lubricant.

  From the results of Example 3 to Example 5, it was considered that the compounds represented by the above general formulas 1 to 2 are preferably sodium salts.

  From the results of Examples 8 to 9, from the viewpoint of improving lubricity, one kind selected from a synthetic polymer that shows water solubility or good water dispersibility and that contains olefin as a monomer and a salt thereof. Alternatively, it was considered preferable to blend two or more kinds in the lubricant.

  According to the present application, a lubricant for warm and hot forging excellent in lubricity is provided. It is considered that the lubricant for warm and hot forging disclosed in the present application has a good effect even in difficult processing such as drawing processing represented by forging processing of a constant velocity joint outer race.

Claims (2)

A lubricant for warm and hot forging containing one or more selected from compounds represented by the following general formulas 1 to 2 and not containing graphite .

(In the above general formula 1, A ₁ is an alkali metal atom, an alkaline earth metal atom, ammonia, or an organic amine.)

(In the above general formula 2, A ₂ is an alkali metal atom, an alkaline earth metal atom, ammonia, or an organic amine. R is an oxygen atom (O) or a carbonyl group (—CO—).)
Furthermore, the warm and hot of Claim 1 which contains the 1 type (s) or 2 or more types chosen from the synthetic polymer which shows water solubility or favorable water dispersibility, and contains the olefin as a structure in the structure, and its salt. Lubricant for forging.