DE69005941T2 - Lubrication process for plastic processing of metallic materials. - Google Patents

Description

Background of the invention 1. Field of the invention

The invention relates to a lubrication method for cold forming metallic materials using an aqueous treatment liquid.

More particularly, the invention relates to cold working (forging, tube drawing, wire drawing, etc.) of metallic materials, for example steel, stainless steels, titanium-based alloys, copper, copper-based alloys, aluminum and aluminum-based alloys using an aqueous lubricating treatment liquid.

2. Description of the state of the art

As aqueous lubricating treatment fluids currently used for cold working of metallic material, fluids comprising a solid lubricant, for example molybdenum disulfide or graphite, at least one member selected from inorganic binders and organic binders, and a surfactant are known.

For cold working carried out with a relatively small deformation, a method is known in which an aqueous lubricating treatment liquid is brought into direct contact with a surface of a metallic grease-free material, followed by drying to form a solid lubricating film thereon.

For a calf deformation with strong deformation, a method of forming a solid lubricant film over a chemical conversion coating is used, wherein a metallic material surface after formation of the chemical conversion coating is brought into contact with an aqueous lubricating treatment liquid and then dried, or a solid lubricating powder is deposited thereon However, when a solid lubricant in a powder state is used, problems such as deterioration of the working environment arise, and thus a lubricant in the form of an aqueous treatment liquid is preferably used. In this case, however, a conventional aqueous lubricant treatment liquid has disadvantages in that it has only unstable and insufficient lubricating properties, and the treated or molded metallic materials rust when standing after the lubricating treatment or molding.

In the above cases, the treatment agents currently used cannot provide stable and desirable lubrication, which often leads to blocking and seizure.

US-A-4 303 537 discloses a liquid lubricant for the treatment of metallic surfaces, the lubricant comprising molybdenum disulfide and graphite, for example in amounts of 15 to 30%, and an acrylic resin.

US-A-4 148 970 discloses an aqueous lubricant for application to metal surfaces to prevent primer removal during metal forming, the lubricant comprising a metal stearate, an emulsifier, titanium dioxide (typically in the form of a pigment useful in the paints art and in a readily water dispersible state, advantageously less than about 200 mesh (US sieve series)) and Xanthomonas hydrophilic colloid.

DE-A-1 030 495 discloses an aqueous lubricant for cold processing of metallic surfaces, the lubricant comprising zinc stearate, talc and an emulsifier.

Summary of the invention

An object of the present invention is to provide a lubricating method for cold forming metallic materials using an aqueous treatment liquid which does not have the above-mentioned disadvantages of conventional aqueous lubricating treatment liquids and has high stability and excellent lubricating properties without causing rusting of the metallic materials.

The above object is achieved by a lubricating method comprising treating the metallic material with a lubricating treatment liquid for cold-formable metallic materials, the liquid comprising 4 to 160 g/l of a metallic soap, 50 to 400 g/l of a solid lubricant as specified below, 0.5 to 40 g/l of a surfactant for uniformly dispersing the metallic soap and the solid lubricant, a colloidal titanium compound as specified below in an amount of 10 to 5000 ppm in terms of titanium, and water.

The aqueous lubrication treatment liquid used in the present invention optionally additionally comprises 5 to 150 g/l of a binder.

Description of the preferred embodiments

The present inventors first found that a lubricating film having an excellent lubricating effect cannot be obtained by a conventional aqueous lubricating treatment liquid and that an excellent resistance to rust can be formed on the surface of a metal article, for example, a cold-worked metal article, by applying an aqueous lubricating treatment liquid comprising, in specified amounts, a metal soap, a solid lubricant of a specified type, and a surfactant and a colloidal titanium compound of a specified type to the surface of the metal article.

Furthermore, the present inventors found that in the above-mentioned aqueous lubricating treatment liquid, the addition of a binder to the metallic soap, the solid lubricant, the surfactant and the colloidal titanium compound effectively increases the lubricating properties due to a synergistic effect of the binder with the other components, for example, the metallic soap and the colloidal titanium compound.

The present invention has been completed on the basis of the above-mentioned findings.

The aqueous lubricating treatment liquid for use in the present invention comprises, as basic components, 4 to 160 g/L of a metallic soap, 50 to 400 g/L of a solid lubricant as specified below, 0.5 to 40 g/L of a surfactant for uniformly dispersing the metallic soap and the solid lubricant in water, 10 to 5000 ppm in terms of titanium of a colloidal titanium compound as specified below, and water.

The metal soap usable for the present invention preferably comprises at least one member selected from salts of fatty acids and hydroxy fatty acids having 12 to 22 carbon atoms with polyvalent metals. The fatty acids and hydroxy fatty acids usable in the present invention include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and hydroxystearic acids. A preferred fatty acid is stearic acid. The polyvalent metals usable in the present invention are preferably selected from calcium, aluminum, magnesium, barium and zinc.

A particularly useful metal soap for the present invention is calcium stearate in a wet state, prepared according to JP-B-60-45680.

The metal soap has a dry matter content of 4 to 160 g/L, preferably 10 to 50 g/L in the aqueous lubricating treatment liquid. If the metal soap is used in an amount of less than 4 g/L, the resulting lubricating film on a metal object exhibits an unsatisfactory lubricating effect. Even if the content of the metal soap is increased to a concentration above 160 g/L, the lubricating effect of the resulting lubricating film on the metal object is also not significantly increased over that resulting from 160 g/L of the metal soap, but the lubricating effect of the solid lubricant is limited by the large amount of the metal soap.

The solid lubricant usable for the present invention comprises at least one member selected from Molybdenum disulfide, graphite, tungsten disulfide, fluorinated graphite, boron nitride and talc.

The content of solid lubricant in the treatment liquid is 50 to 400 g/l, preferably 150 to 250 g/l. A solid lubricant content of less than 50 g/l does not form a sufficient solid lubricating film on the metal article surface. If the solid lubricant content is less than 400 g/l, the lubricating effect will reach a saturation level, so that no further improvement in the lubricating effect will be obtained and only the cost of the aqueous lubricating liquid will increase.

In the lubricating method of the present invention, the lubricating film obtained on the metal article exhibits an excellent lubricating effect when the metal soap is used in a mixing weight ratio of 2:5 to 1:50 to the solid lubricant in the aqueous lubricating treatment solution.

In the aqueous lubrication treatment liquid, a surfactant is used to disperse the metal soap and the solid lubricant in water. There is no specific limitation on the type.

Surfactants generally used include nonionic surfactants, for example, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl esters and polyoxyethylene sorbitan alkyl esters; anionic surfactants, for example, fatty acid salts, alkyl sulfates, alkyl sulfonate, alkyl phosphates and alkyl dithiophosphates; cationic surfactants, for example, aliphatic amine salts and quaternary ammonium salts; and amphoteric surfactants, for example, amino acid-type and betaine-type carboxylic acid salts, sulfuric acid ester salts, sulfonic acid ester salts and phosphoric acid ester salts.

The content of surfactant in the aqueous lubricating liquid for use in the present invention is 0.5 to 40 g/l, preferably 5 to 10 g/l. The content of surfactant in the aqueous lubricating treatment liquid is preferably increased or decreased with respect to the content of solid lubricant. When the content of surfactant is less than 0.5 g/l, the solid lubricant in the treatment liquid insufficiently wetted and a quantity greater than 40 g/l does not significantly increase the dispersing effect of the surfactant.

The aqueous lubrication treatment fluid may be supplemented with another additive, such as a high molecular dispersant, a defoamer and a rust-preventing additive.

The aqueous lubrication treatment liquid also contains a colloidal titanium compound which is a neutralized reaction product of at least one member selected from compounds of sulfuric acid with titanium and compounds of phosphoric acid with titanium, the product being neutralized with an alkaline compound, for example, sodium hydroxide (caustic soda) or the like. The colloidal titanium content of the aqueous lubrication treatment liquid is 10 to 5000 ppm, preferably 50 to 300 ppm, in terms of titanium.

When the colloidal titanium compound is used in an amount of less than 10 ppm, the improvement in the lubricating effect and the rust-preventing effect of the obtained lubricating film on the metal article surface is not significant. However, when the colloidal titanium compound is added in an amount of 10 ppm or more, the improvement in the lubricating effect and the rust-preventing effect of the obtained lubricating film becomes significant and is enhanced by increasing the proportion thereof. Consequently, it is possible to increase the proportion of the colloidal titanium compound to a large extent up to 5000 ppm as long as preparation of the aqueous lubricating treatment liquid is possible.

The colloidal titanium compound usable for the present invention is in the form of colloidal particles consisting of negatively charged micelles. Consequently, the colloidal titanium compound is definitely distinguishable from fine particles of titanium compounds, for example titanium dioxide, usable for pigments, which particles are prepared by finely pulverizing grains of the compounds. The particles thus obtained have do not accumulate an electrical charge when dispersed in water.

The aqueous lubrication treatment fluid contains in addition to the above-mentioned components a binding agent if necessary.

The binder preferably comprises at least one member selected from inorganic and organic binder materials and further acts to enhance the lubricating effect of the lubricating film obtained on the metallic article surface.

The inorganic binder is not limited to a particular type of binder and preferably comprises at least one member selected from borates, phosphates and silicates as mentioned below.

a. Borates

Alkali metal salts, alkaline earth metal salts and ammonium salts of HBO₂, H₃BO₃, H₄B₂O₅, H₂B₄O₇, HB₅O₈, H₂B₆O₁₀, H₂B₈O₁₃, etc.

b. Phosphates

Alkali metal salts, alkaline earth metal salts and ammonium salts of H₃PO₄, HPO₃, H₄P₂O₆, H₃PO₃, H₄P₂O₅, HPO₂, H₃PO₂, H₃P₃O₆ and polyphosphoric acids, for example H₄P₂O₇, H₅P₃O₁₀, H₆P₁₁O₁₃, etc.

c. Silicate

Those are expressed by the general formula M₂O XSiO₂, where M represents an alkali metal atom or an alkaline earth metal atom and X represents a positive integer of 1 to 5.

The organic binder is not limited to a specific type of binder and preferably comprises at least one member selected from water-soluble high molecular compounds, for example, natural high molecular materials such as starch, seaweed, plant mucilage, animal proteins and fermentation mucilage; semi-synthetic high molecular materials made from starch and cellulose; and synthetic polymers, for example, polyvinylpyrrolidone, polyethylene glycol and polyvinyl alcohol.

The binder is used in a solid content of 5 to 150 g/L, preferably 10 to 50 g/L, in the aqueous lubricating treatment liquid for use in the present invention. This solid content is variable depending on the content of the solid lubricant. If the content of the binder is more than 5 g/L, the improvement of the bonding property of the obtained lubricating film on the surface of the metal article is not satisfactory. On the other hand, if the binder is used in an excessively large proportion of more than 150 g/L, the obtained aqueous lubricating treatment liquid has an undesirably high viscosity and thus the amount of the aqueous lubricating treatment liquid adhering to the surface of the metal article becomes too large. Such a large amount of a lubricating film formed on the surface of the metal article clogs the metal nozzle with which the metal article is cold worked.

The aqueous lubricating treatment liquid for use in the present invention can be prepared by dispersing and dissolving the above-mentioned components in predetermined amounts of water in the same manner as conventionally practiced.

When the total proportion of components is relatively small, the finally prepared liquid can be directly used as an aqueous lubricating treatment liquid. When the total proportion of components is relatively high, the obtained prepared liquid is directly used or diluted with an additional amount of water and then used as an aqueous lubricating treatment liquid, in view of the type of metal article, the type of metal deformation and the processing intensity.

The metal object to be treated with the aqueous lubrication treatment liquid is, if necessary, subjected to a chemical conversion process prior to the lubrication treatment.

There is no specific restriction on the type of chemical conversion layer on the metallic material and it can be, for example, zinc phosphate treatment, Iron oxalate treatment, copper oxide treatment, aluminum fluoride treatment and titanium fluoride treatment are usually used according to the metal type.

The aqueous lubricating treatment liquid for use in the present invention is usually applied to a metallic material by a dipping method while maintaining the temperature in a range between room temperature and 80°C.

When the aqueous lubricating treatment liquid is applied at a high temperature, the metal object is also heated and thus the layer of the aqueous lubricating treatment liquid formed on the surface of the metal object may dry due to increased drying effect. On the other hand, when the temperature of the aqueous lubricating treatment liquid becomes too high, the viscosity and concentration of the aqueous lubricating treatment liquid are changed and thus complicated control is required to keep the viscosity and concentration of the aqueous lubricating treatment liquid at a predetermined level by supplying water.

The lubrication method of the present invention is usually carried out in one of the following sequences. The sequence varies depending on the type of metal article, the surface condition and the type of cold working and the amount of deformation.

1. Degreasing - water rinsing - lubricant treatment according to the present invention - drying

2. Degreasing - Water rinsing - Pickling - Water rinsing - Lubricant treatment according to the present invention - Drying (pickling is carried out to remove rust and scale)

3. Degreasing - water rinsing - pickling - water rinsing - chemical conversion treatment - water rinsing - lubricant treatment according to the present invention - drying

4. Degreasing - water rinsing - chemical conversion treatment - water rinsing - lubricant treatment according to the present invention - drying

Degreasing is only carried out when necessary. Pickling is carried out to remove rust and scale from the surface of the metal object.

The metal article is optionally surface-treated by a shot peening treatment or a sandblasting treatment or by the above-mentioned chemical conversion process before the lubrication treatment begins. The type of surface treatment may be selected in view of the type and surface condition of the metal article and the type of intensity of cold deformation.

By applying the special aqueous lubricating treatment liquid according to the present invention, the solid lubricating film formed on the surface of the metal article exhibits excellent lubricating effect and rust-preventing effect compared with those provided by a conventional aqueous lubricating treatment liquid.

The present invention enables a lubricating method for cold forming metal articles, which imparts an excellent lubricating property to the metal articles, so that they are capable of achieving satisfactory high degrees of deformation during cold forming without seizing or blocking, with a high workability and also imparts a high rust resistance to the products thus processed.

Examples

The present invention is further explained by Examples and Comparative Examples, which are not intended to Limit the invention.

Examples 1 to 13 and comparison examples 1 to 19

In each of these examples and comparative examples, a carbon steel bar (JIS G4051) with a diameter of 30 mm was subjected to the following procedures.

Degreasing T Water rinsing T Pickling T Water rinsing Chemical conversion treatment T Water rinsing T Lubrication treatment T Drying

In the degreasing step, the carbon steel rod was treated in a solution containing 20 g/L of Fine Cleaner 4360 (trademark of the degreaser, a product of Nihon Parkerizing Co.) at 70ºC for 10 minutes.

At each water rinse stage, the carbon steel rod was treated with running tap water at room temperature for 60 seconds.

The pickling process was carried out by using Ivit 700 A (trademark: manufactured by Asahi Kagaku K.K.) in an amount of 0.05 g/L at room temperature for 10 minutes.

The chemical conversion process was carried out by immersing the carbon steel rod in an aqueous solution containing a zinc phosphate type chemical conversion film forming agent (trademark: PB181X, manufactured by Nihon Parkerizing K.K.) in an amount of 90 g/L. A chemical conversion film forming agent accelerator (trademark: AC131, manufactured by Nihon Parkerizing K.K.) was applied in an amount of 0.3 g/L at a temperature of 80°C for 15 minutes, except for Examples 12 and 13 and Comparative Examples 1, 8, 9 and 15, in which the chemical conversion did not occur.

The lubrication treatment was carried out by immersing the carbon steel rod in an aqueous lubrication treatment liquid having the composition shown in Table I at a temperature of 80°C for 3 minutes, except for Comparative Examples 6 and 11, and the treatment was carried out at a temperature of 70°C for 3 minutes.

The drying process was carried out by blowing hot air at a temperature of 120ºC for 10 minutes. The drying process can usually be carried out by leaving the metal object in the ambient atmosphere.

The obtained lubricant-treated carbon steel rod was subjected to a cold backward cup extrusion test as shown in Table II.

The lubrication effect was evaluated by measuring the maximum depth of a good inner surface of the extruded test piece (cup) which was produced without causing any contamination or scoring in the form of vertical lines on the inner side of the wall surface of the drawn test piece (cup). The deeper the maximum depth of the good inner surface of the test piece (cup), the better the lubrication effect of the obtained lubricating film on the rod surface. The test results are shown in Table I.

The lubricant treated carbon steel bar was also subjected to the rust resistance test shown in Table III. The rust resistance was evaluated according to the following 4 classes. Class Rating No rust generated. Rust generated on an area corresponding to less than 20% of the total surface area of the test piece (cup). Rust generated on an area corresponding to 20 to 50% of the total surface area of the test piece (cup). Rust generated on an area corresponding to more than 50% of the total surface area of the test piece (cup).

The test results are shown in Table I. Table I Composition of aqueous lubricant treatment liquid Test results Example No. Application of chemical conversion Metal soap (*)1 (g/l) Surfactant (*)9 (g/l) Solid lubricant Binder Colloidal titanium compound (*)5 (ppm) Test piece depth with good inner surface (mm) Rust resistance Type Quantity (g/l) Comparative example Example yes no Table I continued Composition of aqueous lubricant treatment fluid Test results Example No. Application of chemical conversion Metal soap (*)1 (g/l) Surfactant (*)9 (g/l) Solid Lubricant Binder colloidal titanium compound (*)5 (ppm) Test piece depth with good inner surface (mm) Rust resistance Type Quantity (g/l) Example Comparative example yes no

Remark:

(*)1....Metal salt consisting of calcium stearate in the wet state (30% on dry solid weight) prepared in accordance with Japanese Unexamined Patent Publication No. 60-45680.

(*)2....Molybdenum disulfide.

(*)3....tungsten disulfide.

(*)4....Graphite.

(*)5....Neutralization product of titanium phosphate solution with sodium hydroxide (caustic soda), has a pH value of 8.

(*)6....Trisodium phosphate.

(*)7....Carboxymethylcellulose.

(*)8....Polyvinylpyrrolidone.

(*)9....Polyoxyethylene nonylphenol ether, HLB 15, manufactured by Daiichi Kogoyo Seiyaku K.K., trademark: Noigen EA150.

(*)10...Sodium soap type lubricant (trademark: LUB-4601, manufactured by Nihon Parkerizing KK), in an amount of 70 g/l. Table II Cold Backward Cup Extrusion Test Cold Forming Press MSF200 (trademark) manufactured by Fukai Kikai KK Test Apparatus Test Conditions Test piece (cup) Temperature Working speed Deformation of surface 50% Tool Room temperature (cylinder) Punch Die Table III Rust resistance test Test condition Test device Test piece (cup) Constant temperature of 50ºC Constant humidity of 95% Time: 24 hours Program Constant temperature, constant humidity, Cup GLMB-62 (trademark), manufactured by KK Futaba Kagaku Length: 50 mm Diameter: 30 mm

Referring to Table I, in Comparative Examples 1 to 8 in which the lubrication treatment liquid contained the metal soap, solid lubricant and a surfactant and no colloidal titanium compound, the obtained cup with good inner surface was in the range of 30 to 48 mm and more, as compared with Comparative Examples 9 to 13 in which the metal soap content was at a low level of 4 g/L or less and Comparative Examples 10 and 14 in which the solid lubricant content was more than 50 g/L. It is clear that the use of higher amounts of metal soap and solid lubricant in the aqueous lubrication treatment liquids for use in the present invention achieves an improved lubricating effect on the metal article even in the absence of the colloidal titanium compound.

In Comparative Examples 2 to 6 in which the aqueous lubrication treatment liquids contained 5 g/l or more of a binder, the obtained test piece depth (cup) with good inner surface was in the range of 34 to 38 mm, which is more than 32 mm in Comparative Example 1 in which no binder was used. It is therefore apparent that the addition of binder Additionally, the lubricating effect of the aqueous lubricating treatment fluid is increased.

In Examples 1 to 13 in which the aqueous lubricating treatment liquids contained a colloidal titanium compound, the obtained specimen depth (cup) with good inner surface was 36 to 54 mm, which is larger than that of 30 to 48 mm in Comparative Examples 1 to 8 in which the colloidal titanium compound was not used. It is therefore apparent that the addition of colloidal titanium compound is effective in increasing the lubricating effect of the aqueous lubricating treatment liquid when used in the present invention.

In Comparative Example 15 in which the solid lubricant is present in a small amount of less than 50 g/l and in Comparative Examples 16 and 18 in which the colloidal titanium compound is present in a small amount of less than 10 ppm, the obtained test piece depth (cup) with good inner surface had an unsatisfactory value in the range of 16 to 32 mm.

Furthermore, in Examples 7 to 11 in which a binder was used, the obtained test piece depth (cup) with good inner surface was 40 to 54 mm, which is more than 36 to 4 mm in Examples 1 to 6 in which no binder was used. It is therefore apparent that the addition of a binder is effective in increasing the lubricating effect of the aqueous lubricating treatment liquid when used in the present invention.

In Examples 12 and 13 in which the chemical conversion was not applied, the obtained lubricating effect was a little lower than that of Examples 7 and 8 in which the chemical conversion was applied, but was higher than that of Comparative Example 19 in which a conventional aqueous lubricating treatment liquid was applied.

In Comparative Examples 1 to 8 and 9 to 14, in which the colloidal titanium compound was not used, the rust resistance obtained was not satisfactory (Class 1 or 2), whereas in Examples 1 to 13, in which the colloidal titanium compound was applied, the obtained rust resistance was satisfactory (class 3 or 4). Consequently, it is seen that the addition of a colloidal titanium compound effectively increases the rust-preventing effect of the aqueous lubricating treatment liquid when used in the present invention.

Examples 14 to 17 and comparative examples 20 to 29

In each of Examples 14 to 17 and Comparative Examples 20 to 29, the same procedures as in Example 1 were carried out with the following exceptions.

The metal object to be treated was a rod made of 13Cr stainless steel (SUS 410L, JIS G4303) with a diameter of 30 mm.

Pickling was carried out using an aqueous solution of 7% HNO3 and 3% HF at room temperature for 10 minutes.

The chemical conversion treatment was carried out by immersing the stainless steel rod in an aqueous solution containing 40 g/L of an oxalate type chemical conversion film forming agent (trademark: FBA1, manufactured by Nihon Parkerizing K.K.), 20 g/L of an oxalate type chemical conversion film forming additive (trademark: FBA2, manufactured by Nihon Parkerizing K.K.) and 1 g/L of an oxalate type chemical conversion film forming accelerator (trademark: AC-16, manufactured by Nihon parkerizing K.K.) at a temperature of 90°C for 15 minutes.

The lubrication treatment was carried out by dipping the stainless steel rod into an aqueous lubrication treatment liquid having the composition shown in Table IV at a temperature of 80°C for 3 minutes, except that in Comparative Examples 14 and 18, the dipping treatment was carried out at a temperature of 70°C for 3 minutes.

The treated stainless steel bar was subjected to a cold deformation test as shown in Table II. The test results are shown in Table IV. Table IV Composition of aqueous lubricant treatment liquid Example No. Metallic soap (*)1 (g/l) Surfactant (*)9 (g/l) Solid lubricant Binder Colloidal titanium compound (*)5 (ppm) Cold deformation test Depth of good inner surface of test piece (mm) Type Quantity (g/l) Comparative example Example Remark: (*)1 - (*)10 ....as defined above.

In Comparative Examples 20 to 22 using an aqueous lubricating treatment liquid containing no colloidal titanium compound, the depth of the good inner surface of the test piece (cup) was 38 to 54 mm, which is larger than 28 to 32 mm in Comparative Examples 23 to 25. Therefore, it can be seen that when applied to a stainless steel article, aqueous lubricating treatment liquids containing an amount of metal soap and solid lubricant as required by the invention have a lubricating effect not obtained by the conventional lubricating treatment liquid.

In Examples 14 to 17 in which the colloidal titanium compound was used, the depth of the good inner surface of the test piece (cup) was 44 to 58 mm, which is larger than 28 to 32 mm in Comparative Examples 26 to 29 in which the proportion of metal soap and solid lubricant falls outside the scope of the present invention.

It is therefore apparent that the lubricating effect of the aqueous lubricating treatment liquids in Examples 14 to 27 in which the colloidal titanium compound was added is higher than that in Comparative Examples 20 to 22 in which the colloidal titanium compound was not used.

Examples 18 to 21 and comparative examples 30 to 33

In each of Examples 18 to 21 and Comparative Examples 30 to 33, the same procedures as those in Example 1 were carried out with the following exceptions.

The metal object to be treated was a titanium wire (second type, JIS H4600) with a diameter of 3 mm.

Pickling was carried out using an aqueous solution of 7% HNO3 and 3% HF at room temperature for 10 minutes.

The chemical conversion treatment was carried out by immersing the titanium wire in an aqueous solution containing 36 g/l of a chemical conversion agent. fluoride type conversion film (trademark: MET-3851, manufactured by Nihon Parkerizing KK) at a temperature of 60ºC for 3 minutes.

The lubrication treatment was carried out by immersing the titanium wire in an aqueous lubricating liquid having the composition as shown in Table V at a temperature of 80°C for 3 minutes, except that in Comparative Example 33 the treatment temperature was 70°C.

The obtained treated titanium wire was subjected to cold wire drawing as set forth in Table VI.

The test results are shown in Table V. Table V Composition of aqueous lubricant treatment liquid Cold drawing test Tensile (*)11 Example No. Metallic soap (*)1 (g/l) Surfactant (*)9 (g/l) Solid lubricant Binder (*)8 (g/l) Colloidal titanium compound (*)5 (ppm) Type Quantity (g/l) Example Comparative example Good Poor Remark: (*)1 - (*)10 ....as defined above. (*)11 ...........Evaluation Good: No scoring formed during the drawing process. Poor: Scoring generated. Table VI Wire drawing test Test device Single head wire drawing device Test condition Test piece Temperature Drawing speed Tensile Condition Titanium (Second type) 3 mm x 12 mm Room temperature Tensile Die diameter Deformation

Table V clearly shows that in Examples 18 to 21 according to the present invention, the obtained lubricant-treated titanium wires had high resistance to scoring even when 5 drawings were carried out in the cold wire drawing test, whereas in Comparative Examples 30 to 33, the obtained lubricant-treated titanium wire had scoring after the fifth drawing in the cold drawing test.

Claims (10)

1. A lubrication method for cold forming a metallic material, the method comprising treating the metallic material with an aqueous lubrication treatment liquid comprising: (a) 4 to 160 g/l of a metallic soap; (b) 50 to 400 g/l of a solid lubricant, consisting of at least one member selected from molybdenum disulfide, graphite, tungsten disulfide, fluorinated graphite, boron nitride and talc; (c) 0.5 to 40 g/l of a surfactant for uniformly dispersing the metallic soap and the solid lubricant; (d) a colloidal titanium compound which is a neutralization reaction product of at least one member selected from compounds of titanium with sulfuric acid and compounds of titanium with phosphoric acid, the product being neutralized with an alkaline substance and being present in an amount of 10 to 5000 ppm expressed as titanium; and (e) Water. 2. The method of claim 1, wherein the metal soap comprises at least one member selected from salts of calcium, aluminum, magnesium, barium and zinc with fatty acids and hydroxy fatty acids having 12 to 22 carbon atoms. 3. The method of claim 2, wherein the acids for the metal soap are selected from lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and hydroxystearic acid. 4. A method according to any one of claims 1 to 3, wherein the metal soap is present in a weight ratio of 2:5 to 1:50 of the solid lubricant. 5. A process according to any one of claims 1 to 4, wherein molybdenum disulfide is used as solid lubricant, preferably in an amount of 150 to 250 g/l. 6. A process according to any one of claims 1 to 5, wherein the colloidal titanium compound is prepared by neutralizing titanium phosphate with sodium hydroxide (caustic soda). 7. A process according to any one of claims 1 to 6, wherein the colloidal titanium compound is present in an amount of at least 50 ppm. 8. The method according to any one of claims 1 to 7, wherein the treated metallic material is a material having a chemical conversion layer formed thereon, and the layer is treated with the aqueous lubrication treatment liquid. 9. A method according to any one of claims 1 to 8, wherein the aqueous lubrication treatment liquid additionally comprises 5 to 150 g/l of a binder. 10. The method of claim 9, wherein the binder comprises at least one member selected from inorganic borates, phosphates and silicates and water-soluble organic high molecular weight substances.