JPH0832903B2 - Liquid lubricant for cold forging - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention improves a seizure resistance by forming a lubricating coating having excellent heat resistance and lubricity on a friction surface when performing plastic working of steel or the like. The present invention relates to a cold forging lubricant suitable for

[Conventional technology]

The lubricant for plastic working of steel or the like must have sufficient lubricating performance against temperature rise due to deformation heat and frictional heat during working, and increase in new surface. Liquid lubricants having these functions are mineral oils or synthetic oils, or oiliness improvers such as fatty acids and beef tallow in these mixed oils, extreme pressure agents of organic compounds containing phosphorus, sulfur and chlorine, graphite, molybdenum disulfide, etc. There is also a mixture of solid lubricants, etc. However, although these liquid lubricants can be used for processing with low workability, in the case of high workability with high temperature and high surface pressure or molded products with complex shapes, the heat resistance and load resistance of the lubricating coating, Since lubricity is insufficient, seizure occurs and nothing is satisfactory. As a lubricant when plastic deformation is large or when molding a complex shape, a method of plating the surface of the material with a soft metal such as copper or coating a coating of synthetic resin, or a phosphate coating, oxalic acid A chemical conversion coating treatment such as a salt coating treatment is used. In order to perform these conversion coating treatments, there are complicated treatment steps such as degreasing, water washing, pickling, phosphate or oxalate treatment, water washing or hot water washing, neutralization, metal soap lubrication treatment, and drying.
There is a problem that a lot of labor and expense are required. Further, when plating a molded product, it is necessary to remove the coating.

Therefore, in order to improve the above problems and simplify the treatment process, a polyvalent metal cation, orthophosphoric acid and an alkyl alcohol and / or an alkyl aryl alcohol having 10 to 36 carbon atoms, the water content of the composition thereby Acidic lubricant for cold working containing 20% by weight or less (JP-A-47-15)
No. 569), and a reaction product obtained by reacting phosphoric acid with a C _{12 to} C ₂₂ alkyl alcohol or a C _{12 to} C ₂₂ higher alcohol having an iodine value of 70 or less is added to mineral oil and C _{12 to} C ₂₂ . Saturated fatty acids and paraffin derivatives, volatile solvents, waxes,
There is an acidic lubricant (Japanese Unexamined Patent Publication No. 51-26675) containing one or more kinds selected from resins and oils which are easily cross-linked and polymerized.
Although these acidic lubricants show good results for pipe withdrawal, there is a problem that seizure occurs in a processed product having a high degree of processing or in processing a complicated shape.

[Object of the Invention]

The object of the present invention is to make various investigations in order to improve the above-mentioned problems. (EN) Provided is a lubricant for cold forging of steel material, which is significantly improved.

[Structure of the Invention] The present invention relates to a liquid lubricant for cold forging (hereinafter, referred to as a liquid lubricant) in which a powdered lubricant obtained by coating a lubricant surface of a powdered organic compound having a high melting point with a lubricant having a low melting point is dispersed in a lubricating oil. (1)) or a powdered organic compound containing one or more organic compounds selected from organic phosphorus compounds, organic sulfur compounds and organic chlorine compounds and condensed phosphoric acid, and a lubricant obtained by dispersing the lubricant in the lubricating oil. A liquid lubricant for cold forging (hereinafter referred to as liquid lubricant (2)), which is applied to the surface of a steel material and is lubricated by a powdered lubricant containing a lubricating oil that is trapped on the friction surface during processing. A lubricant film is formed on the surface to significantly improve the seizure prevention even for a molded product having a high degree of processing.

As the low-melting-point lubricant in the liquid lubricant (1) of the present invention, castor wax made from castor oil, 12-hydroxystearic acid, sebacic acid, hydrogenated castor oil, stearic acid, methyl 12-hydroxystearate, stearyl 12-hydroxystear Rate, propylene glycol mono 12-hydroxystearate, ethylene glycol mono
12-hydroxy stearate, N-hydroxyethyl ricinoylamide, N-hydroxyethyl 12-hydroxy stearyl amide, N, N'-ethylenebisoleylamide, N, N'ethylenebisricinoylamide, N, N'ethylenebisoctadeca Dienyl amide, N, N 'ethylene bis 12 hydroxy stearyl amide, N, N'ethylene bis stearyl amide,
Examples thereof include synthetic waxes such as N, N'hexamethylenebislysinoylamide, N, N'hexamethylenebis12hydroxystearylamide, and N, N'xylenebis12hydroxystearylamide. On the other hand, the liquid lubricant (1) of the present invention
As the lubricant of the powdery organic compound having a high melting point in, the metal soaps such as lithium stearate, zinc stearate, calcium stearate, sodium oleate, calcium ricinoleate, lithium 12-hydroxystearate, calcium complex, aluminum complex, barium complex, High melting point metal soap such as lithium complex, polyurea, sodium N
Non-soaps such as octadecyl terephthalamate (hereinafter referred to as sodium terephthalamate) are exemplified.
The present invention is to disperse a powdery lubricant having a structure of two or more layers in which a lubricant having a high melting point is coated with a lubricant having a low melting point on a lubricating oil. The amount should be arbitrarily selected, but the preferred amount is 3 to 15% by weight.

The preferable particle size of the above powdery lubricant is in the range of 50 to 1000 μm, but when a molded product having a high working ratio and a large increase rate of surface area is processed depending on the processing conditions, a large particle size may be added.

As the lubricating oil to be blended with the above powdery lubricant, synthetic oils such as poly-α-olefin oil, diester oil, polyol ester oil, polybutene oil, polyglycol oil, silicate ester oil, and mixed oils thereof are used in addition to mineral oil. . The properties of the lubricating oil can be arbitrarily selected according to the processing conditions and working conditions, but the viscosity at 40 ° C is 10 mm ² / s (cSt).
The above is preferable.

The action of the powdery lubricant used in the present invention will be described. The powdered lubricant dispersed in the lubricating oil is trapped between the material and the die working surface or the flat punch surface during processing.
The trapped lubricant is sent to the friction surface along with the deformation of the material and forms a lubricating film to prevent direct contact of metal,
It prevents the seizure. The heat resistance and lubricity of the lubricating coating formed on the friction surface determine the performance of the liquid lubricant.
In the present invention, since the high melting point powder surface is coated with a low melting point lubricant, the effect of improving the heat resistance of the lubricating film by the high melting point powdery lubricant and the effect of improving the lubricity of the film by the low melting point lubricant are obtained. can get. When the content of the powdery lubricant is 1% by weight or less, the amount of the lubricant trapped on the friction surface becomes small and a sufficient film cannot be formed. On the other hand, if it is 20% by weight or more, the viscosity of the lubricating oil increases and the coating property on the surface of the material deteriorates. Further, since no further effect is observed, the amount of the powdered lubricant is preferably in the range of 1 to 20% by weight.

When the particle size of the powdered lubricant is 8 μm or less, the amount of the powdered lubricant trapped on the friction surface during processing is small, so that a sufficient lubricating film is not formed and seizure easily occurs. Also, when the particle size is 1500 μm or more, the dispersion stability decreases, so
The particle size of the powdery lubricant is preferably in the range of 8 to 1500 μm.

In the present invention, in order to further improve the processing performance of the lubricant, at least one organic compound (extreme pressure agent) selected from organic phosphorus compounds, organic sulfur compounds and organic chlorine compounds is added to the powdered organic compound together with condensed phosphoric acid. A liquid lubricant (2) in which a mixed lubricant is dispersed in a lubricating oil is used.

The powdery organic compound in the liquid lubricant (2) of the present invention may include all the high melting point powdery organic compound and the compound forming a low melting point lubricant in the liquid lubricant (1).

Condensed phosphoric acid in the present invention have the general formula _{H n + 2 P n O 3n} + 1 (n = 1~6) chain polyphosphoric acid represented by _{...... (1), H n P} n O 3 n (n = 1-8) Cyclic polymetaphosphoric acid represented by (2), which is a main factor for forming a lubricating coating on the surface of steel. The organic phosphorus compound has a general formula (RO) _n- P (OH) _3-n (5) (wherein R is a saturated or unsaturated hydrocarbon having 1 to 18 carbon atoms, a phenyl group, an alkylphenyl group, and n = 1 or 2) ) Is an acidic phosphoric acid ester represented by. Specific examples of the acidic phosphoric acid ester in these organic phosphorus compounds include monomethyl phosphate, dimethyl phosphate,
Monoethyl phosphate, diethyl phosphate, monobutyl phosphate, dibutyl phosphate, monooctyl phosphate, dilauryl phosphate, diphenyl phosphate, monostearyl phosphate, dioleyl phosphate, phenyloctyl phosphate, methylbutyl phosphate, diisodecyl phosphate,
Examples include dioleyl phosphite, dilauryl phosphite, dibutyl phosphite, and the like. Examples of the phosphonate ester include diisodecyl hydrogen phosphite, dioleyl hydrogen phosphite, dilauryl hydrogen phosphite, and dibutyl hydrodiene phosphite.

Examples of sulfur compounds include sulfurized whale oil, sulfurized olefins, sulfurized lard, sulfurized methyl esters, sulfurized fats and oils, dibenzyl sulfide, didodecyl disulfide, diphenyl disulfide and the like. Examples of the chlorinated compound include chlorinated paraffin wax, chlorinated paraffin, pentachlorofatty acid ester, chlorinated fatty acid, chlorinated fatty acid polyoxyethylene condensate and the like. The above-mentioned organic phosphorus compounds, organic sulfur compounds, and organic chlorine compounds form iron phosphide, iron phosphate, iron sulfide coating, and iron chloride coating on the surface of the steel material by frictional heat to improve seizure resistance and lubricity.

As the powdered organic compound in the liquid lubricant (2), the same type as the synthetic wax or the metallic soap exemplified in the liquid lubricant (1), and having a particle size of 1 μm or more is used. To be These metal soaps,
One or more kinds of synthetic waxes are blended, and a powdered lubricant having a high melting point powder surface coated with a low melting point lubricant and having a particle size of 1 μm or more is also used. Generally, metal soap or non-soap powder surface coated with synthetic wax is preferred. In the case of the liquid lubricant (2), since a two-layer film including a lubricating film and a film formed of a compound such as an organic phosphorus compound is formed in use, the lubricating film is a liquid lubricant. Since a thicker film is formed than the agent (1), seizure resistance and lubricity are obtained.
Therefore, the particle size of the lubricant powder lubricant may be 1 μm or more, which is smaller than that of the liquid lubricant (1). The above metal soap or synthetic wax is confined to the friction surface during processing, and a thick lubricating layer is formed. This is sent to the friction surface together with the plastic deformation of the material, and forms a lubricating film on the film formed by the organic phosphorus compound, the organic sulfur compound, the organic chlorine compound, and the like. That is, a two-layer lubricating film is formed on the surface of the material being processed to further improve seizure resistance and lubricity.

Lubricants of condensed phosphoric acid, organic phosphorus compounds, organic sulfur compounds, organic chlorine compounds and powdered organic compounds to be mixed in lubricating oils should be arbitrarily selected in accordance with the formation of processed parts and the degree of processing. However, the preferable blending amount is 2 to 5% by weight of condensed phosphoric acid, 3 to 15% by weight of one or more kinds of organic phosphorus compounds, organic sulfur compounds or organic chlorine compounds, and 1 of metal soap or synthetic wax. 5 or more seeds
~ 15% by weight.

If the amount of the above additives is small, the reaction lubricating film or metal soap or synthetic wax lubricating film formed on the surface of the material due to frictional heat or plastic deformation heat becomes thin, and metal contact may occur depending on processing conditions, and seizure may occur. May occur. Further, if the amount is too large, there is no further effect, so the above-mentioned ratio is preferable.

The lubricating oil used in the liquid lubricant (2) of the present invention is a synthetic oil such as poly-α-olefin oil, diester oil, polyol ester oil, polybutene oil, polyglycol oil, polyphenyl ether oil, and silicate ester oil, in addition to mineral oil. Oils and mixed oils thereof are used. The properties of the lubricating oil, especially the viscosity, can be arbitrarily selected according to the processing conditions and working conditions, but the viscosity at 40 ° C. is preferably 5 mm ² / S (cSt) or more.

In addition, an antioxidant for preventing deterioration of the lubricating oil, a dispersant for dispersing the powder, and the like can be added within a range not impairing the object of the present invention.

The liquid lubricant containing the organic powder of the present invention is deep-drawn, drawn,
It can be applied to wire drawing, rolling and various extrusion processes. Further, the lubricant of the present invention can be processed only by applying it to the surface of the material, but the application can be achieved by a known spraying, brushing, dipping, roll coating method or the like. Furthermore, since either the lubricant of the present invention or the material to be processed is heated to immerse the material in oil, the surface of the material can be lubricated, which eliminates the need for complicated chemical conversion coating treatment as in the conventional case. It is extremely simple.

Hereinafter, examples of the present invention will be described together with comparative examples,
The present invention is not limited to these examples.

Examples 1 to 22 Mineral oil having a lubricating oil viscosity of 56 mm ² / s (cSt) at 40 ° C. was dispersed and compounded with 3% by weight of a powdered lubricant having a particle size range of 74 to 105 μm shown in Table 1 in oil. The processing performance of the liquid lubricant (1) for cold forging of the present invention was evaluated under the conditions shown below. The results are shown in Table 1.

1. Processing conditions 2. Evaluation method of processing performance A band heater for heating is attached to the mold, the mold temperature is raised in steps of 5 to 20 ° C, and a material coated with lubricating oil at each temperature is processed at a processing speed of 2 mm / s at 10 mm. -15 pieces were processed one by one, and evaluated by the mold temperature (processing performance) that allows processing without seizure. The higher this temperature, the better the heat resistance and lubricity of the lubricating coating.

Comparative Example Lubricating Oil Composition Comparative Example 1 Comparative Example 2 Phosphate coating + sodium stearate As is clear from Table 1, the lubricant for cold forging (1) of the present invention is superior to Comparative Example 1. Also, there is a performance superior to the phosphate coating + sodium stearate treatment.

Example 23 A lubricating oil having a viscosity of 40 ° C. and a viscosity of 150 mm ² / s (cSt) was mixed with 10% by weight of N, N ′ ethylenebis12hydroxystearyl amide having a particle size of 5 to 1500 μm and sodium terephthalamate. The relationship between particle size and processing performance was evaluated by the extrusion method. The results are shown in Fig. 1. As is clear from FIG. 1, when the particle size of the lubricant is 8 μm or more, good processing performance can be obtained.

Example 24 Lubricating oil has a viscosity of 149 to 150 mm ² / s (cSt) of mineral oil at 40 ° C.
1 to 20% by weight of N, N ′ ethylenebis12hydroxystearylamide having a particle size in the range of 210 μm was blended, and the relationship between the blended amount and the processing performance was investigated. The results are shown in Fig. 2. Second
From the results shown in the figure, the effect of addition appears when the amount added to the lubricating oil is 1% by weight or more.

Examples 25 to 31 N, N′-ethylenebisstearylamide was melted by heating at 150 ° C., lithium stearate was mixed in a particle size range of 37 to 44 μm, and the mixture was heated with stirring for 10 minutes and then cooled and flamed. A powder in the form of a powder was obtained. This is crushed with a mixer and the particle size is
Powders in the range of 105 to 149 μm were added to the lubricating oils shown in Table 2
The composition was blended in a weight percentage and the processing performance was evaluated by the backward extrusion processing method. The results are shown in Table 2. As is clear from the results in Table 2, the cold forging lubricant (1) of the present invention provided good working performance.

Examples 32-52 Using a mineral oil having a lubricating oil viscosity of 83 mm ² / s (cSt) at 40 ° C.,
Condensed phosphoric acid, acidic phosphoric acid ester, sulfur-based or chlorine-based organic compound, and metallic soap or synthetic wax having a particle size of powder of 37 to 44 μm are added at the compounding ratio shown in Table 3 to obtain the powder dispersion liquid of the present invention. A lubricant (2) was obtained. After applying this on the surface of the material, the seizure resistance, that is, the processing performance was examined by the forward extrusion method and the backward extrusion method under the following conditions. The results are shown in Table 4.

 The processing conditions and the measurement of the processing performance are as follows.

1. Processing conditions 2. Evaluation of processing performance A heating band heater is attached to the outer periphery of the mold, the mold temperature is raised stepwise by 5 to 20 degrees, and 10 materials coated with lubricant at each temperature are processed 10 The maximum temperature (hereinafter referred to as processing performance) of the mold that can be processed without seizure on the surface was evaluated. It can be said that the higher the temperature, the better the heat resistance and lubricity of the lubricating film formed on the friction surface.

Comparative Example 3 Lubricant comprising phosphate coating treatment + metallic soap (lithium stearate) treatment Comparative Example 4 Base oil: mixed oil of mineral oil + ester oil 38.5 wt% As is clear from Table 4, it is clear that the powder dispersion type liquid lubricant (2) of the present invention is superior to the comparative example in any processing method.

Example 53 Lubricating oil having a viscosity of 40 ° C. and 83 mm ² / s (cSt) mineral oil containing 2% by weight of pyrophosphoric acid, 3% by weight of dioleyl hydrogen phosphite and 10% of lithium stearate or N, N ethylenebisstearylamide. The relationship between the powder particle size of lithium stearate or N, N 'ethylenebisstearylamide and the processing performance was investigated by blending the weight%. The results are shown in Fig. 1. As is clear from Fig. 1, the particle size of the powder is 0.6.
When the thickness is 1 μm or more, the effect begins to appear, but when it is 1 μm or more, the processing performance is rapidly improved.

Example 54 N, N 'Ethylenebis 12-hydroxystearyl amide was dissolved by heating at 150 ° C., barium complex soap having a particle size of 1.8 to 2.3 μm or sodium N octadecyl terephthalamate was added thereto, and the mixture was heated and mixed for about 10 minutes. Then, cool. This was crushed with a crusher, and barium complex soap or sodium N octadecyl terephthalate powder surface was coated with N, N ′ ethylenebis 12-hydroxystearyl amide at 37-44 μm powder 8% by weight, pyrophosphoric acid 5% by weight. Was added to mineral oil (viscosity at 40 ° C .: 83 mm ² / s (cSt)) or polyol ester oil (viscosity at 40 ° C .: 56 mm ² / s (cSt)). These powder dispersion type liquid lubricants (2) were applied to the surface of the material, and the processing performance was evaluated under the same conditions as in Example 1. The results are shown in Table 5. From the results in Table 5, the liquid lubricant of the present invention (2)
Obtained good processing performance.

[Effect of the Invention] Liquid lubricant for cold forging in which a powdered lubricant obtained by coating a lubricant surface of a high melting point powdered organic compound of the present invention with a low melting point lubricant is dispersed in a lubricating oil or a powdered organic compound A liquid lubricant for cold forging in which a lubricant obtained by mixing one or more organic compounds selected from a phosphorus compound, an organic sulfur compound and an organic chlorine compound and condensed phosphoric acid is dispersed in a lubricating oil,
A good lubricating film is formed on the friction surface during processing by simply applying it to the surface of a steel material, which is effective in preventing seizure. improves. Further, since the liquid lubricant for cold forging of the present invention can be processed by simply applying it to the surface of the material, it has a great effect on simplification of the processing process and cost reduction.

[Brief description of drawings]

FIG. 1 shows the relationship between the particle size of powdered lubricant and seizure resistance, that is, processing performance. FIG. 2 shows the relationship between the blending amount of the powdery lubricant and the seizure resistance, that is, the processing performance. FIG. 3 shows the relationship between the particle size of the powder dispersed in the lubricating oil and the processing performance. FIG. 4 is a cross-sectional view of the front extrusion die used for processing the material. FIG. 5 is a cross-sectional view of the backward extrusion metal used for processing the material. 1 ... Material, 2 ... Mold (carbide V ₅ part), 3 ... Punch, 4 ... Band heater, 5 ... Pedestal.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // (C10M 141/10 131: 04 131: 14 135: 02 137: 04) C10N 10:02 10 : 04 10:06 20:00 A 20:06 AZ 30:06 40:24 Z (72) Inventor Fumio Nakano 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd. (72) Narahara Toshikazu 4026 Kuji Town, Hitachi City, Ibaraki Prefecture, Hitachi Research Laboratory, Hiritsu Manufacturing Co., Ltd. (56) References JP 59-187092 (JP, A) JP 51-115507 (JP, A) JP 54-118955 (JP, A) JP 60-71697 (JP, A) JP 60-255895 (JP, A) JP 61-192795 (JP, A) JP 61-183394 (JP, A) KO 52-22948 (JP, B2)

Claims (6)

[Claims] 1. Metal soaps except those having 8 or less carbon atoms, calcium complex soaps, aluminum complex soaps, barium complex soaps, lithium complex soaps, polyurea and sodium N.
-A powdered lubricant obtained by coating the surface of a lubricant of a powdered organic compound having a melting point of 155 ° C or higher selected from the group consisting of octadecyl terephthalamate with a lubricant having a melting point of 60 ° C to 145 ° C. A liquid lubricant for cold forging, characterized by being mixed with a lubricating oil having a boiling point of 150 ° C or higher. 2. The liquid lubricant for cold forging according to claim 1, wherein the metal soap has 18 carbon atoms. 3. The liquid lubricant for cold forging according to claim 1, wherein the powdery lubricant has a particle size in the range of 8 to 1500 μm. 4. The liquid lubricant for cold forging according to claim 1, wherein the powdered lubricant is contained in an amount of 1 to 20% by weight. 5. An acidic phosphoric acid ester to a powdery organic compound,
Sulfurized mackerel oil, sulfurized olefins, sulfurized lard, sulfurized methyl ester, sulfurized fats and oils, dibenzyl sulfide, didodecyl disulfide, diphenyl disulfide,
Patents characterized by blending condensed phosphoric acid with one or more organic compounds selected from chlorinated paraffin wax, chlorinated paraffin, pentachloro fatty acid ester, chlorinated fatty acid and chlorinated fatty acid polyoxyethylene condensate The liquid lubricant for cold forging according to claim 1. 6. The liquid lubricant for cold forging according to claim 1, wherein the powdery lubricant is a metallic soap having a particle diameter of 1 μm or more and coated with a synthetic wax.