JPH02263898A - Solid lubricant for hot roll press - Google Patents

Abstract

PURPOSE:To obtain the subject lubricant effective for preventing of seizure or wear sufficiently adhering to the surface of rolling tool even in coexisting of cooling water, containing solid lubricating substance and specific thermoplastic material. CONSTITUTION:(A) A solid lubricating substance composed of graphite, molybdenum disulfide, boron nitride or talc, etc., is mixed with (B) a thermoplastic substance composed of at least one of hardened oil having 40-100 deg.C melting point, wax and fatty acid in a weight ratio of 5:95-70:30 (preferably 10:90-60:40) and contained in the aimed lubricant.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a solid lubricant used in hot rolling, and more specifically to a solid lubricant used in rolling rolls and guides in hot rolling of seamless steel pipes, steel plates, shaped steel, etc. This invention relates to a solid lubricant suitable for preventing seizure and wear of rolling tools such as shoes.

Conventional technology During hot rolling of seamless steel pipes, steel plates, steel shapes, etc., rolling tools such as rolling rolls for rolling the rolled material and guide shoes for controlling the shape of the rolled material are constantly exposed to high pressure and high temperatures. contact with rolling material. For this reason,
The surfaces of these rolling tools are prone to surface damage such as seizure and abrasion. Such surface damage not only shortens the life of the rolling tool, but also deteriorates the surface quality of the rolled product.For this reason, the use of a lubricant is essential.

Conventionally, seizure and the like on the surface of the rolling tool have been prevented by spraying the rolling tool with a liquid lubricant such as rolling oil or a mixture of rolling oil and water.

However, during rolling, a large amount of cooling water is sprayed onto the rolling rolls and guide shoes, so if a liquid lubricant such as rolling oil is used as described above, the cooling water will spray the liquid lubricant before it reaches the friction surface. There was a problem that it was washed away and could not be effective.

Furthermore, if the amount of liquid lubricant supplied to the friction surface is increased, a large amount of the liquid lubricant will be mixed into the cooling water, making it difficult to separate it from the cooling water. As a result, there have been problems such as a large amount of expense required for recovering the liquid warm lubricant and treating waste water.

Therefore, in recent years, solid lubricants that are not washed away by cooling water have been attracting attention.
The publication proposes a lubrication method in which a graphite solid lubricant is applied to the surface of a rolling roll while rolling. Further, Japanese Patent Publication No. 57-36960 proposes a solid lubricant in which a block body formed by molding graphite powder using a binder is impregnated with a liquid lubricant such as oil or fat.

Problems to be Solved by the Invention However, the solid lubricants of the prior art as described above have a problem in that they have poor adhesion to the surface of a rolling tool and cannot exhibit a sufficient lubrication effect.

The present invention was made to solve the above-mentioned drawbacks of conventional solid lubricants, and its purpose is to provide a solid lubricant that has excellent adhesion to the surface of a rolling tool. be.

Means for Solving the Problems In order to achieve the above objectives, the present inventors conducted intensive research on the adhesion of lubricants to the surfaces of rolling tools such as rolling rolls and guide shoes. A lubricant composition that sufficiently adheres to the surface of a rolling tool was discovered, leading to the completion of the present invention.

That is, the present invention includes a solid lubricant, a solid lubricant substance,
It is composed of a thermoplastic substance with a melting point of 40 to 100°C.

(Solid Lubricating Substance) Examples of the solid lubricating substance used in the present invention include graphite, molybdenum disulfide, boron nitride, and talc.

(Thermoplastic Substance) The thermoplastic substance used in the present invention acts as a binder between solid lubricating substances, and must have a melting point of 40 to 100°C.

If the melting point of the thermoplastic substance is less than 40°C, the solid lubricant will not be able to remain solid. Furthermore, if the melting point of the thermoplastic substance is higher than 100°C, the solid lubricant will not melt and will not exhibit sufficient adhesion since the surface temperature of the tool is generally less than 100°C.

The thermoplastic material satisfying the above-mentioned condition of having a melting point of 40 to 100° C. is composed of one or more of hydrogenated oil, wax, and fatty acid.

Among these, examples of the hydrogenated oil include hydrogenated beef tallow, hydrogenated pork intestine, and hydrogenated castor oil.

Examples of the wax include wax esters such as carnauba wax, spermaceti wax, palm wax, montan wax, and beeswax, and waxes such as paraffin wax, microcrystalline wax, polyethylene wax, polypropylene wax, and camphoria wax.

Furthermore, fatty acids include lauric acid, myristic acid,
palmitic acid, stearic acid, behenic acid, montanic acid,
Examples include hydrogenated beef tallow fatty acids, hydrogenated castor oil fatty acids, and the like.

(Ratio of solid lubricating substance and thermoplastic substance) The weight composition ratio of the solid lubricating substance and thermoplastic substance is 5:95 to 7.
It may be within the range of 0:30, preferably 10:90.
A ratio of 60 to 40 is appropriate.

If the solid lubricant content is 5% by weight without grooves, a sufficient lubricating effect cannot be obtained. On the other hand, when the content of the thermoplastic substance is less than 30% by weight, the bonding force between the solid lubricant substances due to the thermoplastic substance becomes weak, and the solid lubricant becomes brittle.

As a result, when the solid lubricant comes into contact with the rolling tool, it is easily destroyed by impact, vibration, etc. (and cannot withstand use).

[Addition of oily substance]

In addition to solid substances such as solid lubricating substances and thermoplastic substances, oily substances such as mineral oil, liquid oil, silicone oil, etc. may also be added.

(Manufacturing method) The solid lubricant for hot rolling processing of the present invention can be manufactured, for example, by the manufacturing method shown below.

First, a thermoplastic substance or a mixed composition in which an oily substance is added thereto is heated and dissolved, and then a solid lubricant substance is added and stirred to uniformly disperse it.

The mixture thus obtained is poured into a mold having a shape suitable for the location or conditions to which the lubricant is to be applied, and after being cooled to room temperature and solidified, the mold is removed to form a solid lubricant.

Further, a solid lubricant can also be produced by stirring and mixing a solid lubricant and a thermoplastic substance or a mixed composition in which an oily substance is added thereto, and processing and extrusion molding the mixture.

EXAMPLES In order to facilitate understanding of the present invention, examples of the present invention will be described below while comparing them with comparative examples. Note that the present invention is not limited to the following examples, and can be implemented with appropriate modifications.

(Examples 1 to 9) Table 1 shows the components of Examples of the solid lubricant for hot rolling processing of the present invention. In Table 1, the units of numerical values indicating the composition are weight %.

Table 1 (1) Table 1 (2) (Note) The components shown in Table 1 were as shown below.

Graphite talc hardened beef tallow beeswax M-shaped graphite (average particle size 7 μm): LMP #100 (Fuji talc stock: melting point 54℃ (
(manufactured by NOF Corporation): melting point 60 to 67°C (manufactured by Noda Wax Co., Ltd.) Hydrogenated beef tallow fatty acid: melting point 51°C (manufactured by NOF Corporation) Hydrogenated castor oil fatty acid: melting point 72°C (manufactured by NOF Corporation) Paraffin wax : Melting point: 52°C (manufactured by Nippon Seiwa Co., Ltd.) (Comparative Examples 4 to 4) Table 2 shows the compositions of the solid lubricants used as comparative examples. In addition, in Table 2.

The unit of numerical value indicating the composition is weight %.

Table 2 (Note) The following ingredients were used as shown in Table 2.

Polyethylene resin: Polyem 40 (melting point 109°C, manufactured by Rohm and Haas Japan Co., Ltd.) Epoxy resin rapeseed oil: Ebiclone 7050 (melting point 122 to 131'C1 manufactured by Dainippon Ink and Chemicals Co., Ltd.) Nidoenol 8115R (manufactured by Tosue Chemical Co., Ltd.) (Method for producing each solid lubricant) For Examples 1 to 9 and Comparative Example 2, the compositions shown in Tables 1 and 2 were heated and mixed, and then cooled.
A solid lubricant with a diameter of 5 mm and a length of 30 mm was produced.

For Comparative Examples 1 and 3, the solid lubricant and polyethylene resin were mixed uniformly, placed in a mold and dried, and solid lubricants having the same shape as Examples 1 to 9 and Comparative Example 2 were molded. did.

Regarding the composition of Comparative Example 4, the solid lubricant baked after molding was immersed in paraffin wax (melting point 52°C) heated to 150°C for 3 hours, and the paraffin wax was 20%
It was made by impregnating it.

For each of the solid lubricants thus obtained, an adhesion test was conducted using an adhesion tester shown in FIG. 1, and the amount of adhesion was measured. The adhesion test was conducted as follows.

Steel plate 2 immersed in water 1 at temperatures of 60°C and 80°C
(SPCC, 1.2 x 60 x 80 mm) with solid lubricant 3 of Example or Comparative Example placed, load 4 (200 gf)
The amount of lubricant adhered to the surface of the steel plate (g/m'') was measured after the steel plate was moved 5 cm from side to side.

(Results of adhesion test) Table 3 shows the results of the adhesion test.

Table 3 The following can be seen from the results in Table 3.

When the temperature of water 1, that is, the temperature of steel plate 2 is 60°C,
20g/m'' for Examples other than Examples 3 and 5
Attached more than that. The reason why the adhesion amount of Examples 3 and 5 is smaller than that of other examples is because the melting point of the thermoplastic substance in the solid lubricant of Examples 3 and 5 is higher than the steel plate temperature of 60 ° C. This is because there is. On the other hand, in the case of the comparative examples, the amount of adhesion was extremely small.

When the steel plate temperature was 80° C., the melting point of the thermoplastic substance in each example was lower than the steel plate temperature, so a sufficient amount of adhesion was obtained in all the examples. On the other hand, in the case of the comparative example, the amount of adhesion was extremely small as in the case of 60°C.

In this way, it was confirmed that the solid lubricants of the examples of the present invention had much better adhesion than the solid lubricants of the prior art.

As described in detail of the invention, the solid lubricant of the present invention exhibits extremely high adhesion, so when used as a lubricant on the surface of rolling tools such as rolling rolls and guide shears in hot rolling processing, the solid lubricant of the present invention does not adhere to the surface of rolling tools. A sufficient amount adheres and is not washed away by cooling water etc. (good lubrication performance can be exhibited).

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an outline of an adhesion tester. In Figure 1, 1 is water at 60 or 80°C, 2 is a steel plate (dimensions 60 x 80 x 1.2 mm), 3 is a solid lubricant (dimensions φ5 mm x 30 mm), and 4 is a load < 200
gf), 5 is a glass tube for holding the solid lubricant 3. Applicant Yushiguchi Chemical Industry Co., Ltd.

Claims (2)

[Claims] (1) A solid lubricant for hot rolling processing, characterized by containing a solid lubricant and a thermoplastic substance having a melting point of 40 to 100°C. (2) The solid lubricant for hot rolling processing according to claim (1), wherein the weight composition ratio of the solid lubricant and the thermoplastic substance is from 5:95 to 70:30.