SU1068198A1 - Method of preparing the surface of billet for drawing - Google Patents

Abstract

A METHOD OF PREPARING THE SURFACE OF THE PREPARATION FOR WOVENING, which includes applying a lubricant oil coating to the workpiece and then applying an organic process lubricant, characterized in that, in order to improve the surface quality of the resulting product and reduce the drawing force by increasing the adhesion strength of the process lubricant with the lubricant coating, the resulting product will be reduced and the drawing effort will be increased by increasing the adhesion strength of the process lubricant with the lubricant coating. before applying organic technological lubricant, the sub-lubricating coating is heated in an oxidizing atmosphere to a temperature above 10 0c and below the s-flash temperature of the sub-lubricant coating (L, followed by air cooling. C

Description

Oi 00

with

CX) The invention relates to the processing of metals by pressure and can be used in the drawing of metal products, for example, wire. A known method of preparing the surface of the workpiece and drawing, which involves applying a sub-lubricant coating and technological lubricant, moreover, phosphate, lime and other hard coatings are applied as a sub-lubricant coating in order to improve the conditions for technological lubricant entering the deformation zone. At the same time, the lubricating coatings shield (separate) the surfaces of the deformable metal and tool D 1}. : However, solid sublimate coatings do not provide a strong adherence to organic process lubricants, such as salts of fatty acids (soaps), mineral or vegetable oils, due to different chemical nature, and the physical properties of the substance / used as lubricating coatings and lubricants. As a result, in harsh temperature and speed conditions of metal deformation during bursting (failure of continuity) (technological lubrication LAYER may contact juvenile metal surfaces and tools, micro welding, increased wear, increased dragging and breakage. Closest to the invention and the achieved result is the method of Preparing the surface of the workpiece for drawing, which includes applying To the workpiece of lubricating foot oil Coating and then applying 2. A disadvantage of the known method is the low adhesion strength between the sub-lubricant coating and the technological lubricant due to the relatively small size of the liquid molecules. The sub-lubricant coating and the lubricant, therefore, the forces of intermolecular interaction between the coating and the lubricant are relatively small. The speed conditions for deforming the metal, the strength of the layer of technological lubricant and the lubricating coating is not enough. This is accompanied by increased wear of the drawing tool, increased friction, increased dragging and breakage, and a deterioration in product quality. The purpose of the invention is to improve the quality of the surface of the resulting product and to reduce the drag force by increasing the adhesion strength of the process lubricant with the sub lubricant coating. The goal is achieved in that according to the method of preparing the surface of the workpiece for drawing, including applying a lubricant oil coating to the blank and subsequent application of organic process lubricant, the workpiece with the lubricant coating is heated in an oxidizing atmosphere to a temperature above 100 C and below the temperature sub-lubricant outbreaks followed by air cooling. As a result, on the surface of the workpiece, a strong film of heat-treated lubricant is formed, consisting of active molecules of considerable size, strongly adhering to organic technological lubricant. At the same time, more technological lubricant is drawn into the deformation center, which reduces friction and tool wear and improves the quality of the product. The method is carried out as follows. For example, a sub-lubricating oil coating in the form of mineral or vegetable oil or their aqueous emulsions is applied to the workpiece, for example, by dipping. The workpiece with the applied lubricant coating is heated in an oxidizing atmosphere to a temperature of less than 100 ° C and lower than the flash point of the lubricating coating and cooled to J = 3 xy. An organic process lubricant, such as soap powder or cottonseed oil, is then applied, and the preform prepared in this way is subjected to drawing. An increase in molecular weight, molecular strength and molecular interaction forces of liquid lubricants used as a sub-lubricant coating, when heated in an oxidizing atmosphere to a temperature above 100 ° C and below the corresponding flash point, can be done in two ways. The first is for non-polymerizable lubricants, such as mineral oils (industrial 20, cylinder 52, and others, by linking their molecules with oxidant molecules, such as oxygen (oxidative polymerization). The second is for polymerizable lubricants, such as vegetable oils (cotton oil, polymerized cottonseed oil, etc.). Along with the process of oxidative polymerization, a process of thermo-compaction, i.e., the interconnection of molecules, is underway.

The sub lubricating film obtained on the billet has a high burst strength, adheres well not only to the lubricant, but also to the surface of the billet, has a high ductility and ability to shear deformation when the metal is drawn in the deformation zone.

The presence of an oxidizing atmosphere when the preform with a sub-lubricant coating is heated is necessary to enable the oxidative polymerization process of the lubricant used for the sub-lubricant coating.

Heating a billet with a sub-lubricant coating to a temperature below 100 ° C does not completely remove moisture from. composition of lubricating fluid, which impairs adhesion of lubricant to the lubricant coating and reduces the shielding ability of the lubricant coating, since the water contained in the lubricant liquid passivates the surface of the lubricant coating and lubricant, and also does not allow to form strong boundary films on the metal surface In addition, the presence of an oxidizing atmosphere is not sufficiently affected by the Formation of a strong sub-lubricating layer on the surface of the workpiece at temperatures up to. As a result, the lubricating layer in the deformation layer does not have a high shielding ability, which is accompanied by increased friction, wear, increased dragging and breakage.

Heating in the oxidizing atmosphere of the workpiece with a sub-lubricant coating above the flash point of the used lubricant leads to decomposition, combustion of the sub-lubricant fluid, deterioration of its adherence to the process lubricant, and obtaining a brittle soot residue on the metal surface that does not have strength, high screening properties and shear deformation ability m in the drawing of metal. As a result, friction, wear, dragging and breakage increase when the surface quality of the drawn product deteriorates.

Air cooling of a workpiece with a sub-lubricant coating after heating is necessary in order for technological lubricant to be applied subsequently, not heated. Heating of the lubricant reduces its viscosity

ability to be involved in the deformation zone and antifriction efficiency.

Example. A steel billet is drawn from OM steel with a diameter of 5.5 mm, previously riveted to 28%, to a final diameter of 4.5 mm (relative reduction of 33%) on a chain drawing mill at a speed of 30 m / min.

0 As a tool using a single fiber from tungsten-cobalt alloy VK-6, mounted in the holder. Ditch angle b.

Lubricating liquids from the class of vegetable oils and mineral oils and their emulsions in water are used as a lubricant coating: cotton oil CXM), cylinder oil 52 C-52), 5% water emulsion of polymerized cotton oil (5% emulsion PHM) and 5% water emulsion of industrial oil 20 (5% emulsion PS-20.

In the table 1 shows the definition of the flash point used

5 lubricating fluids.

Applying a lubricant coating is carried out by dipping the preform in an appropriate lubricant.

0

Liquid and solid organic lubricants are used as process lubricants: cottonseed oil, C-52 oil, 3% aqueous soap emulsion, 5% aqueous PHM emulsion,

5 soap powder. The experiments are carried out in two versions: by the proposed method by heating a billet with a sub-lubricating coating in an oxidizing atmosphere of an induction furnace at temperatures of 100 ° C, 105 ° C, 0,

0 0.98fgc.r, and asp with subsequent cooling in air and known without heating the workpiece with a sublayer of lubricant applied. The temperature of the sublayer is controlled by contact

5 thermocouple.

For used lubricating liquids, the heating temperatures of the pre-coated sub-lubricant are given in table. 2

0 I

The adhesion strength of the process lubricant with the sub lubricant coating is judged by the amount of their residue on the wire after drawing.

5 Which is determined by the difference in mass of the drawn samples before and after cleaning, as well as by the continuity of the film on the surface of the wire after drawing by means of

0 microscope.

The results of testing the method of preparing the surface of the workpiece for drawing are given in Table. 3

In tab. 4 shows the data, which is confirmed by the values of the force

five

Vol och ni, and zmereni n o go p pe e la and al i tem isomeraizmeritel.

The presented results show that the proposed cncicoe pj oio :: 3icH surface of the grabber to Eolocation helps to increase

firmly:; cling technological

lubricants with grease coating,

as evidenced by the identification of trees

grease not. dragged pro.zo.yuke in

1.3-4.3 times the increase of continuity

reduced drag reduction

by 14-30% compared with the known about

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Claims (1)

METHOD FOR PREPARING THE SURFACE OF THE BILLET FOR DRAWING, including applying to the workpiece under a lubricating oil coating and then applying organic technological lubricant, characterized in that, in order to improve the surface quality of the obtained product and reduce the drawing force by increasing the adhesion strength of the technological lubricant with a lubricating coating, a pre-lubricated coating is heated before applying organic process lubricant. in an oxidizing atmosphere to a temperature above 100 ^s C and below the flash point of the lubricant coating, followed by cooling in air. 00. ζ © □ О>