JPH0369399B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention is applicable to rolling, forging or drawing of iron,
The present invention relates to a high-temperature lubricant composition suitable for hot working of various metals and alloys, such as extrusion of aluminum and copper, drawing of tungsten and molybdenum, and in particular hot rolling of seamless steel pipes.

[Conventional technology]

Conventionally, lubricant compositions of this type include mineral oil, heavy oil, lubricating oil, grease, or mixtures thereof with solid lubricants such as graphite powder and molybdenum disulfide, or alkali metal sulfates and borates. ,
An aqueous dispersion of a fine powder mixture of potassium chloride, sodium triacetate, graphite powder, and an auxiliary agent added as necessary is known.

However, the former lubricant composition is thermally unstable and causes oil decomposition during use.
In addition to having a negative impact on tools and workpieces, there is the problem that oil and oil decomposition products significantly contaminate the working environment.Although the latter type of lubricant composition does not have the same problems as the former, it is particularly useful for seamless steel pipes. There was a problem that satisfactory performance could not be exhibited in the manufacturing of the .

Therefore, the present inventors first developed a high-temperature lubricant composition (Japanese Unexamined Patent Application Publication No. 1983-1991) mainly containing graphite powder and glycols as a solution to the problems of conventional lubricant compositions. 47096), etc.

[Problem that the invention seeks to solve]

The high-temperature lubricant composition previously proposed by the present inventors has achieved some results in that it does not contaminate the working environment and exhibits excellent lubrication performance at high temperatures, but it has not yet been used. Workability was poor at times, and there were problems with the quality of product steel pipes, especially when manufacturing seamless steel pipes.

[Means for solving problems]

The present invention was devised in view of this point of view, and maintains lubricating performance by mainly using graphite powder and polyhydric alcohols, and also by using water-soluble or water-dispersible fatty acid derivatives in combination.
Workability and coating uniformity are greatly improved, and
The present invention provides a high-temperature lubricant composition that has excellent combustion characteristics during rolling and is capable of producing steel pipes with extremely good quality, such as excellent inner surface properties, especially when producing seamless steel pipes. .

That is, the present invention includes 100 parts by weight of graphite powder,
2 to 40 parts by weight of polyhydric alcohol, fatty acid soap,
A high-temperature lubricant composition containing 1 to 30 parts by weight of one or more water-soluble or water-dispersible fatty acid derivatives selected from fatty acid sulfate ester salts and polyoxyethylene fatty acid esters.

The graphite powder used in the present invention may be a natural product or a synthetic product. The graphite powder used has a purity of at least 75% and an average particle size of 100μ or less, preferably 0.3 to 30μ.

In addition, the polyhydric alcohols used in the present invention include ethylene glycol, propylene glycol, trimethylene glycol, α-butylene glycol, β-butylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, pinacol, etc. Examples include glycols such as alkylene glycol, polyglycol such as diethylene glycol and triethyl glycol, and polyalkylene glycol which is a polymer or copolymer of alkylene glycol such as polyethylene glycol, polyethylene oxide, and polypropylene glycol.
Further, trihydric alcohols such as 3-methylpentane-1,3,5-triol and tetrahydric alcohols such as pentaerythritol can be mentioned, and preferably the former glycols give good results. . These polyhydric alcohols may be used alone or as a mixture of two or more.

In addition, the water-soluble or water-dispersible fatty acid derivatives used in the present invention include fatty acid soaps, fatty acid ethylene glycolide sulfate ester salts, fatty acid monoglyceride sulfate ester salts, fatty acid polyhydric alcohol sulfate ester salts, and sulfated oils (rot oil). ), highly sulfated oils, fatty acid sulfate salts such as fatty acid alkyl sulfate salts, fatty acid amide sulfate salts, fatty acid anilide sulfate salts, fatty acid monoalkanolamide sulfate salts, polyoxyethylated castor oil, polyoxyethylene Polyoxyethylene fatty acid esters such as monofatty acid ester, polyoxyethylene difatty acid ester, polyoxyethylene propylene glycol fatty acid ester, polyoxyethylene sorbitan monofatty acid ester, polyoxyethylene sorbitan difatty acid ester, polyoxyethylene trifatty acid ester, etc. can be mentioned. Each of the above fatty acid derivatives may be used alone or as a mixture of two or more.

In the present invention, the blending ratio of each of the above components is 2 to 40 parts by weight, preferably 5 to 30 parts by weight of polyhydric alcohol to 100 parts by weight of graphite powder,
In addition, the water-soluble or water-dispersible fatty acid derivative may contain 1 to 30
parts by weight, preferably 1 to 20 parts by weight. If the amount of polyhydric alcohol used is less than 2 parts by weight per 100 parts by weight of graphite powder, the lubricating performance will be poor, and
If the amount exceeds 40 parts by weight, smoke generation is observed. Furthermore, if the amount of the water-soluble or water-dispersible fatty acid derivative used per 100 parts by weight of graphite powder is less than 1 part by weight, the coating properties will be poor and the coating film will be non-uniform;
If it is more than 30 parts by weight, the strength of the coating film will be weak and smoke will be observed.

The high temperature lubricant composition of the present invention is often dispersed in water and used as an aqueous lubricant dispersion.
The solid content concentration during use is usually adjusted within the range of 5 to 40% by weight, preferably 10 to 35% by weight. Once this solid content concentration is high, for example 30~
The solid content may be adjusted to 50% by weight, and then diluted to an optimum solid content concentration depending on the purpose of use, for example, 5 to 40% by weight. If this solid content concentration becomes too thin, the drying time will be longer and the thickness of the coating film formed will become thinner, making it impossible to obtain good lubrication performance.On the other hand, if it becomes too thick, it will be difficult to apply. Become.

The aqueous lubricant dispersion thus prepared is
This aqueous lubricant dispersion is applied to the surface of the metal to be hot worked and the surface of tools such as mandrels, dies, rolls, etc. using a conventional method, and then dried to form a coating film on the surface of the metal or tool. It is used by forming and then hot working.

In addition, in the high temperature lubricant composition of the present invention, the formability, water resistance, and strength of the coating film can be further improved by adding the lubricant composition in advance or when preparing the aqueous lubricant dispersion. A third component can be added for the purpose of increasing the temperature and for other purposes.

Examples of the third component that can be used for the former purpose, that is, to further improve the formability, water resistance, and strength of the coating film, include vinyl polymers or copolymers, and specifically, acrylic resin,
Various resin emulsions such as vinyl acetate resin, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, isobutylene-maleic anhydride copolymer, polyacrylic acid, styrene-maleic anhydride copolymer There are various water-soluble or water-dispersible synthetic polymers such as polymers. These vinyl polymers or copolymers may be used alone or as a mixture of two or more. When using this vinyl polymer or copolymer, the amount used is 5 to 40 parts by weight per 100 parts by weight of graphite powder.
Parts by weight, preferably 5 to 30 parts by weight.

The blending ratio of graphite powder, other organic compounds, and resin components is 10 to 70 parts by weight, preferably 10 to 50 parts by weight, of the latter based on 100 parts by weight of graphite powder. If the blending ratio of other organic compounds and resin components is low, the coating properties and film forming properties will be poor, and if the blending ratio is high, smoke will be generated.

In addition, other third components include, for example, PH regulators such as alkali and ammonia, film stabilizers,
Conventionally known additives such as antioxidants, surfactants, thickeners, antifoaming agents, rust inhibitors, emulsifiers, extreme pressure agents, and corrosion inhibitors can be mentioned. These additives are added as necessary, and each additive can impart its own characteristics to the lubricant composition or aqueous lubricant dispersion.

〔Example〕

The present invention will be specifically described below based on Examples and Comparative Examples.

Example 1 77% by weight of earthy graphite (purity 88%) with an average particle size of 1μ,
A lubricant composition was prepared by uniformly mixing 11.5% by weight of polypropylene glycol and 11.5% by weight of funnel oil.

A lubricant aqueous dispersion was prepared by dispersing this lubricant composition in water so that the graphite concentration was 20% by weight, and a test piece (material: SKD- 61) to form a lubricating film with a thickness of 30 μm on the surface of the test piece.

The above test piece was fixed to a friction and wear tester, and a lubricating surface pressure (sliding surface pressure) of 19.5Kgf/mm ² was applied to this test piece.
The temperature of the rolled rotating specimen rotating while welding with
Heated to 1000℃ and the relative sliding speed of both specimens was 1.5
The average coefficient of friction during the first 3 seconds of rolling under the condition of m/sec. was determined. The value of the friction coefficient obtained is 0.04
It was good.

Next, using the aqueous lubricant dispersion according to this example, rolling was performed in a three-stand model continuous mill, the thrust coefficient representing the lubrication performance was determined, and the inner surface condition of the steel pipe after rolling was observed. The value of the thrust coefficient obtained was 0.025, and the inner surface condition of the steel pipe was shown in the photo in Figure 1 (Note: The white part in the photo is the reflection of the photographic light. The same applies to the other photos below. ), the results were good.

Example 2 Artificial graphite with an average particle size of 6 μm (purity
A lubricant composition was prepared in the same manner as in Example 1 above, except that 99.9%) was used, and its performance test was conducted in the same manner as in Example 1. The obtained friction coefficient value was 0.04, which was good.

Example 3 A lubricant composition was prepared in the same manner as in Example 1 above, except that natural scaly graphite (purity 98%) with an average particle size of 6μ was used as the graphite powder, and its performance test was conducted in the same manner as in Example 1. I went there. The obtained friction coefficient value was 0.04, which was good.

Example 4 A lubricant composition was prepared in the same manner as in Example 1, except that sodium oleate was used in place of funnel oil, and its performance test was conducted in the same manner as in Example 1. The obtained friction coefficient value was 0.04, which was good, and the inner surface quality of the steel pipe was also good.

Example 5 A lubricant composition was prepared in the same manner as in Example 1 above, except that tripropylene glycol was used instead of polypropylene glycol, and its performance test was conducted in the same manner as in Example 1. The obtained friction coefficient value was 0.04, which was good.

Example 6 A lubricant composition was prepared in the same manner as in Example 1, except that the blending ratio of polypropylene glycol was 19.2% by weight and the blending ratio of funnel oil was 3.8% by weight. The performance test was carried out using the following methods. The obtained friction coefficient value was 0.04, which was good, and the inner surface quality of the steel pipe was also good.

Example 7 A lubricant composition was prepared in the same manner as in Example 1 above, except that polyethylene glycol was used in place of polypropylene glycol, and polyoxyethylenated castor oil was used in place of funnel oil. A performance test was conducted in the same manner as in 1.
The obtained friction coefficient value was 0.04, which was good, and the inner surface quality of the steel pipe was also good.

Example 8 Carboxymethyl cellulose as dispersant 1.9
A lubricant composition was prepared in the same manner as in Example 1 above, except that % by weight was added, and its performance test was conducted in the same manner as in Example 1. The obtained friction coefficient value is
The thrust coefficient was 0.04, and the thrust coefficient was 0.026, both of which were good.The inner surface of the steel pipe was also good as shown in the photograph in FIG.

Example 9 A lubricant composition was prepared in the same manner as in Example 8 above, except that pentaerythritol was used in place of polypropylene glycol, and its performance test was conducted in the same manner as in Example 1. The obtained friction coefficient value was 0.04, and the thrust coefficient value was 0.029, both of which were good. Furthermore, the inner surface properties of the steel pipe were also good.

Example 10 78.4% by weight of the above earthy graphite, 11.8% by weight of polyethylene glycol, 4% by weight of polyoxyethylated castor oil, 4% by weight of acrylic resin as the third component
and hydroxypropylcellulose as a dispersant
A lubricant composition was prepared by uniformly mixing 1.8% by weight. Performance tests on this lubricant composition were conducted in the same manner as in Example 1. The value of friction coefficient obtained is 0.04 and the value of thrust coefficient is 0.028
Both were good. The inner surface of the steel pipe was also in good condition as shown in the photograph in FIG.

Example 11 74.1% by weight of the above earthy graphite, 11.1% by weight of polypropylene glycol, 3.7% by weight of funnel oil, and 11.1% by weight of a mixture of acrylic resin and styrene-maleic anhydride copolymer resin as the third component were uniformly mixed and lubricated. A drug composition was prepared. Performance tests on this lubricant composition were conducted in the same manner as in Example 1. The obtained friction coefficient value was 0.04 and the thrust coefficient value was 0.026, both of which were good.
In addition, the inner surface of the steel pipe was good, and the strength of the coating film and the water resistance of the coating film were also good.

Example 12 77% by weight of the above earthy graphite, 7.7% by weight of polyethylene oxide, 3.8% by weight of polyoxyethylated castor oil
A lubricant composition was prepared by uniformly mixing 11.5% by weight of a mixture of acrylic resin and ethylene-vinyl acetate copolymer resin as the third component. Performance tests on this lubricant composition were conducted in the same manner as in Example 1. The obtained friction coefficient value was 0.04 and the thrust coefficient value was 0.021, both of which were good. In addition, the inner surface quality of the steel pipe is good,
The coating film strength and water resistance of the coating film were also good.

Comparative Example 1 A lubricant composition was prepared by uniformly mixing 77% by weight of the earthy graphite and 23% by weight of polyethylene glycol, and its performance test was conducted in the same manner as in Example 1 above. The obtained friction coefficient value was 0.04,
It was difficult to apply the aqueous lubricant dispersion and the workability was poor. Furthermore, the inner surface quality of the steel pipe was unsatisfactory, as shown in the photograph in FIG.

Comparative Example 2 A performance test was conducted in the same manner as in Comparative Example 1, using polyoxyethylated castor oil instead of polyethylene glycol. The obtained friction coefficient value was as high as 0.05, and the coating film strength was low. Furthermore, the inner surface quality of the steel pipe was unsatisfactory as shown in the photograph in FIG.

Comparative Example 3 A performance test was conducted in the same manner as in Comparative Example 1, using an ethylene-vinyl acetate copolymer resin instead of polyethylene glycol. The obtained friction coefficient value was 0.06, the thrust coefficient value was high at 0.035, and the inner surface of the steel pipe was poor as shown in the photograph in FIG.

Comparative example 4 80% by weight of the above earthy graphite and 20% by weight of acrylic resin
A lubricant composition was prepared by uniformly mixing the above, and its performance test was conducted in the same manner as in Example 1 above. The obtained friction coefficient value was 0.05, the thrust coefficient value was as high as 0.035, and the inner surface quality of the steel pipe was also poor.

〔Effect of the invention〕

According to the present invention, by using a water-soluble or water-dispersible fatty acid derivative in addition to polyhydric alcohols, the lubrication performance of the coating film formed on the surface of metal or tools subjected to hot working is improved. can be done. Furthermore, it has excellent workability, produces less smoke and odor during hot processing, and can improve the quality of the product surface, especially the quality of the product steel pipe (for example, the inner surface of the steel pipe) when manufacturing seamless steel pipes. can.

[Brief explanation of drawings]

1 to 3 are Examples 1, 8, and 10 according to the present invention.
A micrograph of the metal surface structure taken to observe the inner surface properties of a steel pipe obtained by rolling it in a model continuous mill using the high-temperature lubricant composition of
4 to 6 are micrographs similar to those of the above-mentioned Examples, showing cases where the lubricant compositions of Comparative Examples 1 to 3 were used.

Claims (1)

[Claims] 1. 100 parts by weight of graphite powder, and 2. polyhydric alcohol.
~40 parts by weight, and 1 to 30 parts by weight of one or more water-soluble or water-dispersible fatty acid derivatives selected from fatty acid soaps, fatty acid sulfate salts, and polyoxyethylene fatty acid esters. Characteristic high-temperature lubricant composition. 2. The high-temperature lubricant composition according to claim 1, which contains a water-soluble or water-dispersible vinyl polymer or copolymer as a third component.