JPS63130236A - Lubrication processing method for steel for cold forging - Google Patents

Abstract

PURPOSE:To simplify a processing process, and to improve productibity by executing a blast by iron and zinc grains after mechanical descaling, forming an iron and zinc alloy layer on the surface of a material to be processed, thereafter, executing a lubrication processing. CONSTITUTION:Cold forging steel is descaled by mechanical descaling, thereafter, a blast by iron and zinc grains is executed, and an iron and zinc alloy layer 4 is formed on the surface 1 of a material to be processed. Subsequently, a lubricating film 3 is formed by executing a lubrication processing by using a lubricant, etc., consisting essentially of mineral oil, and animal and vegetable oil, in a lubrication processing process. According to this method, the process is omitted and the productivity can be improved.

Description

[Detailed Description of the Invention] Industrial Application Field This invention relates to a lubrication treatment technology for cold forging steel for pressing such as wire rods and steel bars. This invention relates to a method for lubricating cold forging steel that reduces equipment costs and improves productivity.

Conventional technology and its problems Conventional lubrication treatment for cold forging steel for presses is performed by descaling (descaling) the material to be treated by mechanical descaling, such as Shot Plus 1, as shown in Figure 3, which shows the general treatment process.
After removal of black scale), a lubricating base treatment such as zinc phosphate is applied, and after washing with water, a reactive soap treatment such as sodium stearate is applied, followed by drying. but,
Such a lubrication treatment consisting of a lubrication base treatment and a reactive soap treatment has the following drawbacks.

That is, both lubricating base treatment with zinc phosphate and reactive soap treatments such as sodium stearate require a long treatment time due to chemical reactions, and the treatment temperature is approximately 80'C, requiring a rise in temperature. In addition, productivity is low due to the large number of processing steps, high equipment costs, and long processing times.Substrate treatment liquids such as zinc phosphate are strong acids with P = 2 to 3. Therefore, if the water washing in the post-process is insufficient, there is a risk of rust, the waste liquid treatment cost for pollution prevention is high, and rough sludge treatment is required (forming a zinc phosphate film). During this process, iron phosphate is produced as sludge by melting the base metal.
, it has disadvantages such as requiring equipment for that purpose.

Purpose of the Invention The present invention was made to solve the above-mentioned drawbacks of the conventional method. By combining lubrication treatment with a commercially available lubricant such as a resin-based lubricant, the conventional lubrication base treatment with zinc phosphate, etc. and reactive soap treatment such as sodium stearate can be omitted, and the treatment process and This paper aims to propose a lubrication treatment method that shortens treatment time, reduces equipment costs, and improves productivity.

Structure of the Invention The method for lubricating steel for cold forging according to the present invention includes descaling a material to be treated by mechanical descaling such as shot blasting, and then blasting with iron and zinc particles to coat the surface of the material to be treated with iron.・It is characterized by forming a zinc alloy layer, and forming thereon a lubricant film containing, for example, mineral oil, animal/vegetable oil as the main component, or a lubricant film containing fluororesin as the main component. .

That is, in order to omit the conventional lubrication base treatment with zinc phosphate, etc. and the reactive soap treatment with sodium stearate, this invention performs a plus treatment with iron and zinc particles before the lubrication treatment, and then removes the iron and By forming a zinc alloy layer, the adhesion of lubricant is promoted, and a good lubricant film is obtained by lubrication treatment with commercially available mineral oil, animal/vegetable oil, or lubricant whose main component is fluorine resin. I'll go.

Blasting of iron/zinc grains in the present invention is usually carried out using iron grains as cores, as disclosed in Japanese Patent Publication No. 59-9312, and particles in which the surface of the core is coated with zinc via an iron/zinc metal layer. In this method, an iron-zinc alloy layer is formed on the surface of the wire by plastination. The amount of the iron-zinc alloy layer deposited is preferably 1 gJ to 40 g4 in consideration of lubricity, economy, and productivity (workability). i.e. 1 g
If it is less than 4, the lubricity and retention of the lubricating film mainly composed of mineral oil, vegetable oil, or fluororesin in the subsequent process will be insufficient, while if it is more than 40 g4, the time required for adhesion will be long. This is because it takes. The iron/zinc coating may be plated, but since the coating formed by blasting is porous, it is suitable for retaining the lubricating coating.

Here, the lubricant used in the lubricating process of this invention will be explained.

Examples of mineral oils that can be used include machine oil and spindle oil, and examples of animal and vegetable oils that can be used include rapeseed oil, coconut oil, and cow oil. In addition, it is desirable that the composition contains fatty acids and higher alcohols as oiliness improvers, sulfur, chlorine, and phosphorus compounds as extreme pressure additives, as well as viscosity index improvers, antifoaming agents, and the like.

Lubricants whose main component is fluororesin have the following characteristics: the fluororesin has a higher softening point than other polymer components, is heat resistant, and has an extremely low coefficient of friction.
If graphite is added to this fluororesin or thermally decomposed during wire drawing, the C-CF bond is broken C! The lubricating ability is further improved by containing a chlorine compound that produces ferrous chloride or ferric chloride film by forming ferrous chloride or ferric chloride. In addition, as a solvent, it dissolves the fluororesin and has excellent quick drying properties.
Furthermore, it is preferable to use a material that can form a uniform film, such as 1.1.1 trichloroethane.

In any case, the type of lubricant is not limited, but a commercially available lubricant having the above-mentioned components may be used. However, when selecting a lubricant, consider the processing conditions of the lubricated material, such as wire drawing conditions (area reduction ratio, wire drawing speed, etc.), and generally the cold forging in the subsequent process.
It is necessary to consider the amount of lubrication required after machining.

DISCLOSURE OF THE INVENTION BASED ON THE DRAWINGS FIG. 1 is a block diagram showing the lubrication treatment process of the invention, and FIG. 2 is a schematic diagram showing the structure of the lubricant film of the invention.

In other words, this invention descales cold forging steel by mechanical descaling (shot blasting, etc.) in the descaling process, and then forms an iron/zinc alloy layer on the surface of the material by adding iron/zinc particles. Then,
In the lubrication process, lubrication is performed using a lubricant whose main component is mineral oil, animal or vegetable oil, or a lubricant whose main component is a fluorocarbon resin.

This lubrication treatment is performed by dipping at room temperature (processing time varies depending on the wire drawing speed, but about 1 minute is sufficient)
. In the case of lubrication treatment using a lubricant whose main component is mineral oil or animal/vegetable oil, drying is not required, but in the case of a lubricant whose main component is a fluororesin, it is dried by natural drying or the like. By the way, whether or not to use mineral oil, animal/vegetable oil, etc. when performing cold forging by pressing after drying is determined by the conditions of cold forging (for example, area reduction rate in forward extrusion, processing speed, etc.). good.

The structure of the lubricating film of this invention is shown in Fig. 2. When lubricated with mineral oil or animal/vegetable oil, an iron-zinc alloy layer is formed on the surface of the base iron (1) as shown in Fig. a. (2
) on top of which is an oil film mainly composed of mineral oil, animal/vegetable oil (3)
is formed on the iron-zinc alloy layer (2) formed on the surface of the base steel (1) as shown in the figure. A lubricating film (4) mainly composed of a fluororesin is formed on the
Further, as shown in Figure C, a lubricating oil film (3) containing mineral oil, animal/vegetable oil as a main component is further formed on a lubricating film (4) containing fluororesin as a main component.

By the way, the conventional film structure is shown in Figure 4, which includes a lubricating base film (5) made of zinc phosphate, etc., a reactive layer (zinc stearate film) (6), and a reactive soap film made of sodium stearate (2). It is configured.

Next, embodiments of the invention will be described.

Example 2 After shot blasting a test material (335C) with a diameter of 8 mm (projection density: approximately 300 kg, Kentan material: 0.3 or + φ steel pole), approximately 10 g, Q was applied to the wire surface by iron/zinc particle blasting. An iron-zinc alloy layer was formed, and a lubrication treatment was performed using a lubricant having the composition shown in Tables 1 and 2 (treatment temperature: room temperature, treatment time 1 minute), and air drying was performed. Table 3 shows the results of backward extrusion of the lubricated material using a press and examination of the indentation depth of the seizing source at an extrusion area reduction rate of 70%. Note that backward extrusion was tested without applying any lubricant.

For comparison, Table 3 shows the same descaling material treated with zinc phosphate (total acidity approximately 35 points).

The test results of samples treated with sodium stearate (concentration: about 2 points, temperature: 80°C, treatment time: 5 minutes) are also shown.

As is clear from Table 3, all of the examples of the present invention have improved cold forging properties compared to the conventional zinc phosphate treatment and sodium stearate treatment. From this result, it is clear that the conventional lubricating base treatment and reactive soap treatment can be omitted.

Below are the margins: Table 1 Table 2 Table 3 Tables 3 and 3 Margins As described in detail, this invention applies blasting with iron and zinc particles after descaling by mechanical descaling to form an iron-zinc alloy layer on the surface of the treated material. A lubricant containing, for example, mineral oil, animal/vegetable oil as a main component, etc.
By forming a lubricating film using a commercially available lubricant such as a lubricant whose main component is a fluororesin, the conventional lubricating base treatment and reactive soap treatment can be omitted, which simplifies the treatment process and reduces equipment costs. The effects of this invention include a reduction in heat, a reduction in processing time, and an improvement in productivity, as well as eliminating the problem of rust due to the omission of zinc phosphate treatment, and the ability to save energy through room-temperature treatment. Extremely large.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the lubrication treatment process of the present invention, Fig. 2 is a schematic diagram showing the lubricant film structure of the invention, Fig. 3 is a block diagram showing the conventional lubrication treatment process, and Fig. 4 is a block diagram showing the conventional lubrication treatment process. This is a cross-sectional view showing the structure of the lubricating film. 1... Substrate, 2... Iron/zinc alloy layer, 3... Lubricating film containing mineral oil, animal/vegetable oil as a main component, 4... Fluorine resin film.

Claims (1)

[Claims] In the method of descaling and lubricating steel for cold forging, after descaling by mechanical descaling, blasting with iron and zinc particles is performed to coat the surface of the material to be treated with iron and zinc.
1. A method for lubricating cold forging steel, comprising forming a zinc alloy layer and then performing lubrication treatment.