JP2001146599A - Lubricant for plastic working of steel material and steel material for plastic working having lubricating layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a lubricant for plastic working of a steel material which can form a film exhibiting excellent lubricity without worsening the rust prevention properties and to produce a steel material for plastic working which has a lubricating film which is not damaged or corroded until the material is delivered to and plastically worked at a working plant and which can satisfy the highest lubrication conditions. SOLUTION: The lubricant for plastic working of a steel material, which is applied to at least a part of the surface of the steel material for plastic working to prevent the corrosion of the material, is prepared by adding fine diamond particles to a liquid rust-preventive agent and hence can form a film having not only lubricity but also rust-preventive properties. A steel material for plastic working having a lubricating layer with a dry thickness of 1-100 μm is also produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricant used for plastic working of steel such as a steel pipe, a steel plate, a steel wire or a steel bar, and a steel used for plastic working having a lubricating layer. The present invention relates to a plastic working lubricant which forms a coating film satisfying the above requirements, and a plastic working steel to which the lubricant is applied.

[0002]

2. Description of the Related Art Conventionally, when a steel material is subjected to plastic working, a method of applying a lubricant based on mineral oil, fatty oil or synthetic oil immediately before the plastic working is generally employed.
However, this lubricant application process is an off-line facility outside the plastic working equipment, and the process of selecting a lubricant depending on the type of steel material is a significant obstacle to improving the efficiency of the plastic working process. It is one of the causes of the work environment deterioration problem.

In order to cope with such a situation, by applying a lubricant to the surface of the steel material in advance by the steel material manufacturer, not only the best lubrication conditions are satisfied, but also the trouble of applying the lubricant immediately before plastic working. It has been proposed that both the steel material manufacturer and the plastic working side have great effects such as productivity improvement and labor saving.

[0004] However, in general, the steel material maker and the plastic working machine are hardly the same, and it is necessary to always transport the steel material from the steel material manufacturer side to the plastic working side by any transportation method. Occurs. For this reason, the steel material manufactured by the steel material manufacturer is exposed to the wind and rain before it is actually plastic-worked by the plastic working machine, and the lubricating film applied to the steel material surface is damaged and corroded. Occurs. As a result, the plastic workability in the later plastic working process is impaired, and this may cause a product trouble of plastic working crack. Accordingly, a lubricant for plastic working of steel materials is required to have excellent lubricating properties and at the same time excellent rust prevention properties.

[0005] However, extreme pressure additives and oiliness improvers generally contained for imparting lubricity deteriorate rust prevention, and corrosion inhibitors contained for imparting rust preventive deteriorate lubricity. Therefore, it is difficult to achieve both lubricity and rust prevention. On the other hand, there is a phosphate film (+ metal soap) as a film that has both lubricity and rust prevention. However, the process is complicated and the productivity is deteriorated, and the global environment is degraded due to the waste liquid. There is. That is, it has been difficult to realize a lubricant for plastic working of steel that easily forms a film having both lubricity and rust prevention.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and provides a lubricating agent for plastic working of steel, which easily forms a film having both lubricity and rust-preventive properties, and the lubricant is applied. To provide a steel material for plastic working.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present inventors have developed a lubricant for plastic working of steel, which easily forms a film having both lubricity and rust prevention, and a lubricant for the same. The coated steel for plastic working was studied diligently.
As a result, the invention described below has been attained.

(1) A lubricant for plastic working of steel, characterized by forming a film having lubricity and rust prevention by adding fine diamond particles to a liquid rust inhibitor applied for the purpose of preventing rust of steel. .

(2) The lubricant for plastic working of steel as described in (1) above, wherein the diamond fine particles have an average particle diameter of 1 to 100 nm.

(3) The lubricant for plastic working of steel as described in (1) or (2) above, wherein the content of the diamond fine particles is 10 ^-4 to 1% by mass.

(4) In a steel for plastic working obtained by applying a lubricant to the entire surface or a part of the surface of the steel, the diamond fine particles are added to a liquid rust inhibitor applied for the purpose of rust prevention of the steel. A dry film having a lubricating property and a rust-preventing property, wherein
A steel material for plastic working having a lubrication layer of 0 μm.

(5) The lubricant has an average particle diameter of 1 to 10
5. A steel material for plastic working having a lubricating layer as described in 4 above, comprising fine diamond particles of 0 nm.

(6) The plastic working steel material having a lubricating layer as described in (4) or (5) above, wherein the lubricant has a content of diamond fine particles of 10 ^-4 to 1% by mass.

(7) The lubricating layer is formed after the surface of a steel material to which a lubricant is to be applied is cleaned, and then a lubricating layer is formed.
A plastic working steel material having a lubricating layer according to claim 1.

(8) The plastic working steel material having a lubricating layer as described in (4) above, wherein the steel material is any one of a steel pipe, a steel plate, a steel wire and a steel bar.

Hereinafter, the present invention will be described in detail. The liquid rust preventive used in the present invention may be any liquid rust preventive commonly used for the purpose of preventing rust on steel materials, and may be used alone or in combination of two or more.

The fine diamond particles used in the present invention are formed by exploding trinitrotoluene explosive in a container, using free carbon obtained as a carbon source, and using high pressure and high temperature obtained by the explosion to form fine diamond particles. It was synthesized by the impact compression method.

These fine diamond particles are contained in a liquid rust inhibitor at 10 ^-4 to 1% by mass, and the average particle size is 1 to 100 n.
It is preferred to use m. If the content is less than 10 ^-4 mass%, the lubricity decreases, and the object of the present invention cannot be achieved. When the content is more than 1% by mass, the diamond fine particles aggregate, which also causes the lubricity to decrease. If the average particle size is less than 1 nm, the lubricity is reduced, and the object of the present invention cannot be achieved. When the average particle size is larger than 100 nm, the diamond fine particles work as an abrasive, which again causes a decrease in lubricity.

The lubricant for plastic working of steel according to the present invention may optionally contain a pour point depressant, a viscosity index improver, an antioxidant, a corrosion inhibitor, a detergent / dispersant, an oiliness improver, an extreme pressure additive, a rust inhibitor. Additives, defoamers, fluorescence improvers, colorants, alkaline additives, water repellents, adhesives, anti-separation agents, surfactants, solvents and the like can be added. As a method of applying the lubricant, there are dipping, brushing, spraying, roller and the like, and any method can be adopted.

The lubricant for plastic working of steel of the present invention is preferably applied so as to have a thickness of 1 to 100 μm when dried. If the film thickness is less than 1 μm, the lubricity and rust resistance are reduced, and the object of the present invention cannot be achieved. Further, from the viewpoints of economy and workability, the upper limit of the film thickness is preferably about 100 μm.

Examples of the method for cleaning a steel material to which the lubricant for plastic working of steel of the present invention is applied include degreasing, pickling, and blasting.

Examples of the form of the steel material to which the lubricant for plastic working of the present invention is applied include a steel pipe, a steel plate, a steel wire, a steel bar and the like.

[0023]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. As the liquid rust inhibitor, a commercially available product comprising a mineral oil-based wax, a solvent having a flash point of 30 ° C. or higher, and an anionic surfactant, which is used for the purpose of preventing rust of steel materials, was used. Diamond fine particles having the average particle size and content shown in Table 1 were added to this liquid rust preventive agent, to thereby obtain Examples 1 to 15 and Comparative Examples 2 to 21. In Comparative Example 1, no fine diamond particles were added.

These lubricants are brushed to a dry film thickness of 30
It was applied to a degreased steel sheet so as to have a thickness of μm, and left naturally at 20 ° C. for 1 hour. The width 30 mm applied in this manner,
A plane sliding test was performed on a test piece having a length of 300 mm and a thickness of 2.3 mm. Further, these lubricants are applied to a degreased steel pipe by immersion so as to have a dry film thickness of 30 μm.
It was left naturally at 0 ° C. for 1 hour. A salt spray test was performed using the test piece having an outer diameter of 50.8 mm, a thickness of 6.0 mm, and a length of 150 mm applied as described above. The measurement results are shown in Table 1.

In the flat sliding test, the test piece was 40 m wide.
This was carried out by using a flat mold having a length of 30 mm and a length of 30 mm with a load of 1000 f and pulling out at a constant speed of 200 / min. The friction coefficient (lubricity) was calculated from the pulling load at this time. The salt spray test was conducted according to JIS Z 2371
And the time until rust was generated (rust prevention) was determined.

[0026]

[Table 1]

From Table 1, it can be seen that the test pieces of Examples 1 to 15 obtained by using a lubricant obtained by adding a diamond particle having a predetermined average particle size and content to a liquid rust preventive applied for the purpose of rust prevention of steel have good lubricity. In addition, in Comparative Example 1 in which diamond fine particles were not added, but Comparative Examples 2 to 21 in which the average particle diameter and the content of the diamond fine particles were not specified, lubricating properties were reduced.

[0028]

As described above, the lubricant for plastic working of steel according to the present invention is obtained by adding diamond fine particles having a predetermined average particle size and content to a liquid rust preventive applied for the purpose of preventing rust of steel. In addition, a film exhibiting excellent lubricity without deteriorating rust prevention can be formed. Furthermore, since the steel material for plastic working having the lubricating layer of the present invention is coated with a lubricant that forms a film that exhibits excellent lubricity without deteriorating rust resistance, it is actually applied to plastic working people. The lubricating film is not damaged and corroded before plastic working, and the best lubricating conditions can be satisfied.

[Brief description of the drawings]

FIG. 1 is a view showing a partial cross section of a plastic working steel material having a lubricating layer as an example of the present invention.

[Explanation of symbols]

 1: Steel material 2: Film having both lubricity and rust prevention

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C10M 125: 02) C10M 125: 02) C10N 30:06 C10N 30:06 30:10 30:10 40:20 40:20 (72) Inventor Junichi Okamoto 1 Kimitsu, Kimitsu-shi, Chiba F-term in Nippon Steel Corporation Kimitsu Works (reference) 4H104 AA04A EA08A EB10 LA06 PA23 PA34 QA12

Claims (8)

[Claims] 1. A lubricant for plastic working of steel, characterized by forming a film having lubricity and rust prevention by adding fine diamond particles to a liquid rust inhibitor applied for the purpose of preventing rust of steel. 2. The diamond fine particles having an average particle size of 1
The lubricant for plastic working of steel according to claim 1, wherein the thickness is from 100 to 100 nm. 3. The content of the diamond fine particles is 10
^{3. The} composition according to claim 1, wherein the content is from ^-4 to 1% by mass.
The lubricant for plastic working of steel according to 1. 4. In a steel for plastic working obtained by applying a lubricant to the entire surface or a part of the surface of a steel material, the lubrication is performed by adding fine diamond particles to a liquid rust preventive applied for the purpose of rust prevention of the steel material. Dry film thickness of 1 to 100 μm, characterized in that the agent forms a film having lubricity and rust prevention properties
A steel material for plastic working having a lubrication layer of m. 5. The lubricant has an average particle size of 1 to 100 n.
5. The steel material for plastic working having a lubricating layer according to claim 4, wherein the steel material contains m diamond fine particles. 6. The lubricant according to claim 4, wherein the content of the fine diamond particles is 10 ^-4 to 1% by mass.
Or a steel material for plastic working having the lubricating layer according to 5. 7. The steel material for plastic working having a lubricating layer according to claim 4, wherein a lubricating layer is formed after cleaning the surface of the steel material to which the lubricant is to be applied. 8. The steel material for plastic working having a lubricating layer according to claim 4, wherein the steel material is any one of a steel pipe, a steel plate, a steel wire, and a steel bar.