DE2920857A1 - PROCESS FOR COLD FORMING OF METALLIC MATERIALS - Google Patents

Description

Process for cold forming metallic materials

The invention relates to the field of metallurgy. Objects for which the application of the invention is possible and Appropriate are processes for the cold forming of metallic materials, for example for extrusion as well for drawing wire, profiles, pipes and sheets, especially for pulling with hydrodynamic lubrication.

Ji ¹ Solid, semi-solid or liquid lubricants are used for drawing metallic materials. Among other things, alkali stearates dissolved in water are known as liquid lubricants. These lubricants are either fed to the drawbar as a liquid or applied to the drawbar, dried and then transported into the drawbar together with the drawbar. These lubricants have a relatively low dynamic viscosity and are therefore not suitable for drawing higher strength materials. So is z. B. sodium stearate can only be used for strength up to about 1000 N / mm. In addition, a continuous mode of operation with multi-stage forming is ^{technologically difficult to achieve due to the solvent contained in the lubricant with a boiling point of 100 0} G. The drying is time-consuming and must be carried out very carefully, as the dynamic viscosity of the lubricant

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is even lower if the drying process is insufficient. Farther It is disadvantageous that this lubricant does not have a fat-dissolving effect, so that under certain circumstances a degreasing agent can also be used Pretreatment of the drawn material is necessary.

The aim of the invention is to expand the field of application solid and semi-solid lubricants and in reducing the technological effort in cold forming metallic materials.

The invention is based on the object of developing a method in which a homogeneous lubricant layer of high dynamic viscosity, as is necessary when cold forming high-strength materials, is achieved. This object is achieved with a method in which a lubricant is applied to the material to be formed or the tool work surfaces, in which in an organic solvent with a boiling point ^ 200 ⁰ G alkali, alkaline earth, ammonium and zinc or related metal or metal. Light metal salts of acids with more than 10 carbon atoms in the molecule, preferably of acids with 15 to 20 carbon atoms in the molecule.

Technical benzene can be used as the solvent and calcium stearate with 29 % metal oxide content can be used as the alkaline earth salt. To achieve short drying times, the invention provides that a solvent with a boiling point <30 ⁰ C or a solvent mixture is used in which at least one mixture component has a boiling point <30 ⁰ C and the other (s) a boiling point ^. 30 ⁰ C has or have, the lubricants being in dissolved and / or dispersed form. As a solvent or solvent mixture component with a boiling point <30 ⁰ C, chlorine-fluorine-

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Hydrocarbons, fluorine-bromine-hydrocarbons, chlorine-bromine-fluorine-hydrocarbons and / or other chlorinated or fluorinated organic compounds, such as, for example, trifluoroacetone, can be used. As a solvent mixture component having a boiling point> 30 ⁰ C it can benzene and / or trichlorethylene are used.

The invention also provides that the lubricant mi '.; cationic, anionic, amphoteric or nonionic Surfactants can be mixed. In this case, any residual lubricant films can be easily and conveniently removed with V / ater, that can also be heated. Fatty acid amides, higher alkylamines and their substitution products can be used as cationic surfactants to serve. As anionic surfactants, alkylarylsulfonates, Aikylsulfate, Alkylsulfonate, Aikylarylphosphate, Alkylphosphate and their substitution products are used will. Betaines such as sulfate betaines and sulfobetaines can be used as amphoteric surfactants. As a non-ionic Surfactants can be ethylene oxide adducts and fatty acid alkyl amides be used.

In the method according to the invention, the lubricant is im liquid state applied homogeneously to the drawing material surface and remains as a solid after removal of the solvent Lubricant layer adhere to the drawing material, whereby a pretreatment of the drawing material with lubricant carriers in the Can usually be dispensed with. The lubricant combines the advantages of solid lubricants due to their high dynamic drawing viscosity also for drawing higher strength Materials can be used and can be produced with relatively little effort, with the advantages of liquid or semi-solid lubricants that guarantee a homogeneous application of lubricant. The lubricant is at continuous multi-stage drawing process can be used. The homogeneous lubricant layer on the drawing material is guaranteed stable target relationships and the resulting advantages. With the inventive use of solvents

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vein with a boiling point of ⁴ C Ju ⁰ U or solvent mixtures in which at least one liemisch component has a boiling point <C 3U ⁰ C, high working speeds can be achieved in multi-stage wire drawing due to the low boiling point of the solvent used, even with an intermediate coating. The use of surfactants in the lubricant according to the invention avoids the aggressive pickling or the usual treatment with organic solvents which is otherwise required to remove the residual lubricant film. As a result, there is a considerable saving in organic solvents in the case of benzene or chlorinated hydrocarbons for the stripping, which considerably reduces the costs that otherwise arise when the drawing material is to be further processed. The exclusion of organic solvents results in simplified conditions with regard to occupational safety, and no environmental protection problems or increased costs resulting from filtration or cleaning of the extracted gases are required.

Embodiment

example 1

An expedient way of realizing the invention consists in a method in which a lubricant which contains benzene as an organic solvent is applied to the material to be reshaped. Calcium stearate with a metal oxide content of 29 % is dissolved in this solvent. This lubricant is particularly suitable for hydrodynamic pulling, for example of spring steel wire. With the lubricant, a spring steel wire with an initial diameter of 10 mm and an initial strength of 1600 ET / mrn with B = 15 % could be reshaped by over 80 %. After leaving the drawing nozzle, the drawing material has an excellent surface quality and shows a homogeneous layer of remaining solid lubricant on its surface.

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Example 2

Ια 0.8 1 benzene, 150 g calcium stearate are brought into solution. 1 l of trichlorofluoromethane are added to this liquid containing Ga stearate. This lubricant leaves behind in half the usual time a firm and firmly adhering lubricant coating on the goods to be drawn. At the Due to the very good dynamic viscosity properties of the lubricant, high drawing speeds can be drawn and achieve degrees of deformation.

Example 3

A lubricant is applied to one liter of trichlorethylene that contains 90 g of calcium stearate with the addition of of 18 g of Okiadecylbenzenesulfonat in dissolved and / or suspended form contains. The resulting solution or suspension After application to the drawing material and subsequent removal of the solvent, it leaves a lubricant film with a high level of lubricant dynamic viscosity, both before and after forming, e.g. B. drawing of wire, pipes or profiles, but also after extrusion, can be easily removed with water.

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Claims (1)

Patent claims: 1. A method for cold forming metallic materials, characterized in that a lubricant is applied to the forming material or the 'Jerkzeugarbeitsflächen, in which in an organic solvent with a boiling point ^ 200 ⁰ G alkali, alkaline earth, ammonium and zinc - Or related metal or light metal salts of acids with more than 10 carbon atoms in the molecule, preferably of acids with 15 to 20 carbon atoms in the molecule, are contained. 2. The method according to claim 1, characterized in that as Solvent technical grade benzene is used. 3. The method according to claim 1, characterized in that calcium stearate is used with a metal oxide content of 29 % in the solvent. 4. The method according to claim 1, characterized in that the solvent has a Koan point <C 30 C or consists of an organic solvent mixture, the at least one mixture component has a boiling point <30 ⁰ C and the other CnJ a boiling point> 30 ⁰ C or » possess, the lubricants being in dissolved and / or dispersed form® o. Method according to claim 4 _5, characterized in that the solvent or solvent mixture component with a boiling point <30 ⁰ C chlorine-fluorine-hydrocarbons, fluorine-bromine-hydrocarbons, chlorine-bromine-fluorine-hydrocarbons and / or other cni.orierte or fluorinated organic compounds, such as trifluoroacetone, are used, » bo The method according to claims 4 _S characterized dadruch _s that the solvent mixture component with a boiling point h. 30 ⁰ G 909851/0622 ORlGiNAL INSPECTED -ä- 292085? Benzene and / or trichlorethylene can be used. 7. The method according to claim 1 _s, characterized in that the lubricant is mixed with cationic, anionic, amphoteric or nonionic surfactants. tu method according to claim Y, geKennzeich.net characterized in that as cationic surfactants fatty acid amides, higher alkylamines and whose substitution products are used. y. Process according to Claim 7, characterized in that the anionic surfactants used are alkyl aryl sulfonates, alkyl sulfates, alkyl sulfates, alkyl aryl phosphates, alkyl phosphates and their substitution products. 10 »The method according to claim J, characterized in that the amphoteric surfactants used are i3etaines, such as sulfate betaines and sulfobetaines. 11. The method according to claim Y _5, characterized in that ethylene oxide adducts and fatty acid alkylolamides are used as nonionic surfactants. 9098 51/0 622