JPS6365240B2 - - Google Patents

Description

[Detailed description of the invention]

[Field of Application of the Invention] The present invention relates to a lubricant for plastic working that forms a lubricating coating on a metal surface by utilizing deformation heat and frictional heat during the working of metal during plastic working such as cold working of metal. [Background of the Invention] A lubricant for plastic working of metals must have sufficient lubrication performance against temperature rise due to deformation heat, frictional heat, etc. during processing, and increase in new surfaces. These lubricants include water-soluble and water-insoluble liquid lubricants whose main ingredients are mineral oil, synthetic oil, or a mixture thereof, semi-solid lubricants such as metal soap and beef tallow, and sulfur-based, chlorine-based, A mixture of extreme pressure agents such as phosphorus, solid lubricants such as graphite and molybdenum disulfide, etc. is used. The above-mentioned lubricants can be used in cold working with a low degree of processing, but in cases where the degree of processing is high with high temperatures and surface pressures, or for molded products with complex shapes, the load carrying capacity and heat resistance of the lubricant may be There is no satisfactory product due to the occurrence of seizure due to insufficient quality. As a lubricant when molding objects with large plastic deformation or complex shapes,
A method of plating a soft metal such as copper on the surface of the material, a method of coating with a synthetic resin film,
Alternatively, there may be phosphate coating treatment, oxalate coating treatment, etc. In order to apply these lubricating coating treatments, sufficient pretreatment is required, and the process of forming the coating is complicated, so there are problems in that it requires a great deal of labor and expense. Further, there are problems in terms of film removal after molding, etc. In recent years, phosphorus salts and their salts,
Lubricants containing boric acid and its salts, alkali metal carbonates, nitrates, sulfates and their hydroxides, layered silicates, etc. have been proposed (Japanese Patent Application Laid-Open No. 1989-1999).
Publication No. 73089). These lubricants are composed of a water-soluble glass powder containing P ₂ O ₅ , B ₂ O ₂ , M ₂ O (M is an alkali metal), a layered silicate or a mixture of the above, and water.
It cannot be used as a lubricant for cold working because it cannot exhibit lubricity at low temperatures such as during cold working. [Objective of the Invention] The object of the present invention is to provide a method that can be sufficiently applied to high working conditions such as high temperatures and high surface pressures, as well as processing of molded products with complex shapes, and which also provides lubricity even during cold working at low temperatures. It is an object of the present invention to provide a lubricant for plastic working which has a lubricating coating and which is easy to form. [Summary of the Invention] The first aspect of the present invention is a lubricant for plastic working in which condensed phosphoric acid or an acid salt thereof is blended with a lubricating oil. If this lubricant is applied to the surface of the metal material to be plastic processed or the surface of the mold and processing is started, the lubricant will react using heat such as frictional heat generated on the surface of the metal material during processing. , a lubricating film of phosphate with excellent heat resistance is formed on the surface of the metal material. Further plastic working increases the surface area of the metal material, creating a new metal surface, but the condensed phosphoric acid or its acid salts mixed in the lubricating oil reacts with that surface, forming a new lubricating film. It is formed. In this way, plastic working is performed while a lubricating film is formed from the start of processing to the end of processing. The second aspect of the present invention is a lubricant for plastic working in which a lubricant is blended with condensed phosphoric acid or an acid salt thereof and a lubricant other than oil such as a fatty acid. The formation of a lubricating film is further promoted by the inclusion of fatty acids and the like. In the present invention, the bound phosphoric acid or its acid salt includes polyphosphoric acid, pyrophosphoric acid, metaphosphoric acid,
Mention may be made of acidic pyrophosphates, acidic polyphosphates and acidic metaphosphates. As the acidic pyrophosphate, sodium acid pyrophosphate and potassium acid pyrophosphate are effective; as the acidic polyphosphate, sodium acid polyphosphate and potassium acid polyphosphate; and as the acid metaphosphate, sodium acid metaphosphate is effective. One or more of these condensed phosphoric acids or acid salts thereof are contained in the lubricating oil. Lubricating oil, mineral oil,
When using an ester oil or a mixed oil thereof, it is preferable to uniformly suspend and disperse the condensed phosphoric acid or its acid salt using an emulsifier. The emulsifier should be arbitrarily selected depending on the type of the lubricating oil and the condensed phosphoric acid or its acid salt; for example, esters of polymeric succinic acid are effective. When the lubricating oil is a water-soluble lubricating oil, such as polyethylene glycol, polypropylene glycol, polyoxyethylene glycol monoether, polyoxypropylene glycol monoether, etc., it is not necessary to add an emulsifier. Therefore, in the present invention, the lubricating oil should be selected depending on the processing temperature and processing degree of the process in which it is used. Unlike when condensed phosphoric acid and lubricating oil are used alone, lubricating oils containing condensed phosphoric acid or its acid salts contain a mixture of both condensed phosphoric acids and lubricating acids, so they are susceptible to frictional heat and deformation generated on metal surfaces during machining. Using heat simply and directly, a film of condensed phosphoric acid can be formed on the metal surface while being processed. That is, the coating formed during processing can prevent the seizure problem that occurs when lubricating oil is used alone, even when the processing is high and involves high temperatures and surface pressures, or when processing molded products with complex shapes. Furthermore, since the coating can be automatically formed on the surface of the molded article while processing it, the formation of this lubricating coating is easier than in the past. Furthermore, even during processing at low temperatures such as cold working, frictional heat and deformation heat are generated on the metal surface during processing, and this heat forms a film of condensed phosphoric acid, so lubricants for cold working are It can also be used as As described above, the lubricant for plastic working of the present invention is fully applicable to processing with a high degree of processing at high temperatures and high surface pressures, and the formation of a lubricating film of condensed phosphoric acid is simple. Demonstrates sufficient lubricity even during cold working at low temperatures. In the present invention, a lubricant other than lubricating oil is contained in addition to condensed phosphoric acid or its acid salt. In addition to fatty acids, the lubricants include graphite, MoS ₂ , BN,
Solid lubricants such as Teflon, carbon fluoride, and metal soap can be used. By using these lubricants in combination, the formation of a film of condensed phosphoric acid is promoted and the lubricating performance is improved, and this tendency is particularly remarkable when fatty acids are used. Fatty acids include straight chain fatty acids such as butanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, etc. and 2,4 hexadienoic acid, trans-2, cis-4 decadienoic acid, 6,10,14-hexadecatrienoic acid,
cis-9, cis-12 octadecadienoic acid, cis-9,
Examples include unsaturated fatty acids such as cis-12 and cis-15 octadecatrienoic acid and oleic acid, and dimer acids obtained by heating unsaturated fatty acids or dimerizing them using a catalyst. Note that the solid lubricant can also be used in combination with the fatty acid. In the case of a lubricant for plastic working consisting of a lubricating oil and condensed phosphoric acid or its acid salt, it is desirable that the lubricating oil be 95 to 80% by weight and the condensed phosphoric acid or its salt be in a range of 5 to 20% by weight. In the case of a lubricant for plastic processing consisting of a lubricating oil, condensed phosphoric acid or its acid salt, and a fatty acid, lubricating oil 97~
60% by weight, 2 to 20% by weight of condensed phosphoric acid or its acid salt, and 1 to 20% by weight of fatty acid. The lubricant for plastic working obtained in the present invention can be used by applying the lubricant to the metal material or mold surface to be plastic worked, for example, by brushing, spraying, dipping, fluid dipping, dripping, etc. A coating method is adopted. Further, after heating either the plastic working lubricant of the present invention or the metal material to be plastic worked, and immersing the metal material in the lubricating oil to apply a lubricating film treatment to the surface of the metal material, Since it can also be processed, complicated processes such as conventional film processing are unnecessary, making it extremely simple. [Examples of the Invention] Next, the effects of the plastic working lubricant of the present invention will be shown by Examples, but the present invention is not limited thereto. Examples 1 to 10 As shown in Fig. 1, mineral oil (manufactured by Nippon Oil Co., Ltd.: FBK150 ) was used as a base oil and a plastic working lubricant having the composition shown in Table 1 was applied. Next, as shown in Figure 2, the extrusion angle was 120 degrees, the drawing diameter was φ6 (processing rate was 64
Material 1 was processed using a forward extrusion method using a mold (made of carbide) 2 and a punch 3, and the processing performance was evaluated. The evaluation results are shown in Table 2. In addition, the evaluation method of machining performance is to attach a band heater 4 to the mold 2,
The mold temperature was raised stepwise from room temperature by 5 to 10°C, and 20 pieces of material 1 coated with lubricating oil were processed, and the highest mold temperature at which no seizure phenomenon occurred on the surface of the material after processing was measured. The higher the temperature, the better the processing performance of the lubricant. In addition, the following examples were compared and contrasted with those of the present invention. Comparative example 1 (commercially available processed oil) Base oil: Mineral oil Remaining additives Fatty oil Chlorine Sulfur content 43% by weight 12% by weight 6% by weight Comparative example 2 Phosphoric acid (P ₂ O ₅ in terms of oxide) 41.2 mol% Sodium carbonate (Na ₂ O in terms of oxide) 39.3 mol% Sodium monophosphate (K ₂ O in terms of oxide)
12.5 mol % and 7 mol % of boric acid (in terms of oxide B ₂ O ₃ ) were mixed, and this was heated and melted at 900° C. for 30 minutes to vitrify it. This vitrified sample was then placed in water for 20 minutes.
wt% dissolved. Comparative Examples 1 and 2 were also evaluated for processing performance in the same manner as Examples 1 to 10. These results are the second
Shown in the table.

【table】

[Table] 〓Cross-sectional area before processing - Cross-sectional area after processing〓
* Processing rate=

Claims (1)

[Scope of Claims] 1. A lubricant for plastic working, characterized in that a lubricating oil is blended with condensed phosphoric acid or an acid salt thereof. 2. A patent characterized in that the condensed phosphoric acid or its acid salt is one or more components selected from metaphosphoric acid, polyphosphoric acid, pyrophosphoric acid, acidic metaphosphate, acidic polyphosphate, and acidic pyrophosphate. A lubricant for plastic working according to claim 1. 3. A lubricant for plastic working characterized by blending a lubricating oil, condensed phosphoric acid or its acid salt, and a lubricant other than oil. 4. A patent characterized in that the condensed phosphoric acid or its acid salt is one or more components selected from metaphosphoric acid, polyphosphoric acid, pyrophosphoric acid, acidic metaphosphate, acidic polyphosphate, and acidic pyrophosphate. A lubricant for plastic working according to claim 3. 5. The plastic working lubricant according to claim 3, wherein the lubricant other than oil is a fatty acid.