SU1530383A1 - Method of producing bimetallic articles - Google Patents

Abstract

The invention relates to the manufacture of bimetallic products and can be used in the manufacture of pipes, bearing rings and other products. The purpose of the invention is to improve the quality of bimetallic products. When welding friction billet 1 and 2 of various metals, the diameter D _{3 of the} inner billet 2 is chosen equal to the average value of the inner diameter D _{2 of the} outer billet, and the taper angle of the outer surface β of the inner billet 2 is chosen more by 5 ... 10 ° taper angle α inner the surface of the outer workpiece 1. This ensures the displacement during welding of friction-heated metal layers of impurities and oxides into burr and an increase in the quality of the joint, as well as a reduction in energy consumption during production. 3 dw., 2 tabl.

Description

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The invention relates to rolling production and can be used in the manufacture of bimetallic rings for bearings, track fingers, bimetallic pipes, piston engine cylinders, heat pipes and other products for various purposes.

The aim of the invention is to improve the quality of bimetallic products by providing a reliable connection of the contact surfaces.

The essence of the method is that the joint is subjected to the joint with the optimum for displacing oxides during welding by friction with taper angles and diameter values.

FIG. 1 shows the preparation of blanks in the form of truncated cones; in fig. 2 - their joint with simultaneous sealing; in fig. 3 - rolling bimetallic billets.

The method is carried out in the following way.

Liners 1 and 2 of the required dimensions are made of dissimilar materials, their contact surfaces are prepared by mechanical processing, they are joined, sealed and rolled. The preparation of the contact surfaces of the workpieces is made by making them in the form of truncated cones, and their articulation and sealing of the contact surfaces are carried out simultaneously under the action of axial pressure and intense friction.

Example. In laboratory conditions, welding of blanks from steel 45 and bronze Br05C5S5 is carried out. The blank length E is 50 mm, the outer diameter d, i of the bronze blank is 40 mm, the inner diameter is 20 mm. The inner surface of the steel billet is machined with a taper of 20 °, the outer surface of a bronze billet with a taper of 5-15 °. The parameters of the welding process in all experiments remain constant: the axial force of 600 MPa;

900

; h

clamping force

rotational speed of 850 MPa.

In each of the experiments, the value of the moment of friction is measured as an indicator of the energy intensity of the process.

The effect of the taper angle at the time of friction is shown in Table. one.

An analysis of the experimental results shows that with a change in the taper angle a and the outer surface of the inner blank from 5 to 15 ° with a constant taper angle p of the inner surface of the outer blank, which in this case is 20 ° and provides the lowest coefficient of friction, the friction moment increases from , up to 13.6 kgm in experiments 1-6, and then remains at the same level. The almost constant value of the frictional moment with the taper angle of the outer surface of the inner blank above 10 ° explains

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with a slight decrease (from 203 to 199 mm) of the initial contact area. At the same time, metallographic studies of the material of the welded joint show that, in experiments 1 and 2, oxide films remain in the joint, which degrades the quality of the finished product. This circumstance can be explained by the fact that at small angles of taper, the area of the initial contact is increased and I have no oxide films on contact 0 in the future.

Consequently, the lowest energy consumption for friction welding of bimetals with good quality of the joint is provided at the taper angle of the outer surface of the inner billet p, which is in the range (a + (5 ... 10).

In addition, experiments are being carried out to determine the effect of the external diameter of the tip of the cone of the inner part on the quality of the bimetal joint. The dimensions of the outer steel billet remain the same, and the outer diameter d.j of the apex1.1 of the cone of the inner billet varies from 50 to 67.2 mm, which corresponds to the smallest. D | and the largest diameters of the inner surface of the outer blank. The mean diameter of the inner surface is indicated by da.

The dependence of the quality of the joint on the size of the outer diameter of the cone of the inner blank is shown in Table. 2

The analysis of the experimental results shows that the optimum joint quality of the blanks was obtained at 6 m, i.e. when d, j corresponds to the average diameter di of the cone of the inner surface of the outer hundred, 1 billet. This situation can be explained by the fact that when the outer diameter of the tip of the inner cone is equal to the average cone diameter of the inner surface of the outer billet, the oxide films are displaced by heated friction metal layers from the middle of the billet to the front. Grat 3.

The invention allows to improve the quality of bimetallic products with a simultaneous decrease in energy consumption for their production.

Claims (1)

Invention Formula Method for the production of bimetallic products, in which billets are welded, 0 one of which is made with internal, and the other with external truncated cones, articulated along conical surfaces under the action of axial pressure and intense friction, characterized in that, in order to ensure reliable 5 when connecting contact surfaces when using blanks with different taper values, the outer diameter of the tip of the cone of the inner blank is chosen equal to the average value 0 five 0 five the diameter of the cone of the inner surface of the outer billet, and the taper of the billet is determined by the dependence of p a + (5 ... 10), where p is the angle of taper of the outer surface of the inner blank, hail; a - angle of taper of the inner surface of the outer billet, hail. Table 1 table 2 FIG. 2 Fig.d