Method of butt contact resistance welding of dissimilar metals

 

(57) Abstract:

The method can be used when welding metals with different physical-mechanical properties, for example, high-speed steel construction. At the end of one part perform the ledge, and on the other end part of the recess. The ledge perform at the end of items with high resistivity, and a recess on the end face of the workpiece with a lower specific resistance. The ratio of the areas of the cross section of the parts in the junction is chosen from the condition of their direct proportionality resistivity of the material of the welded components. The protrusion and the recess can be performed with a tapered part, and with a cross section in the form of a polygon. The method can significantly improve the welding quality. 2 C.p. f-crystals, 4 Il.

The invention relates to contact the resistance welding of metals with different physical-mechanical properties, such as high-speed steel construction, for manufacturing of end cutting tool or other products requiring high reliability in vibration, fatigue fracture and shock loads.

The known method of flash butt welding of parts made of dissimilar metals, in which Shrivenham end IU the UE is softened and under the force of compression. plastically deformed, fills the volume of the undercut [1].

The disadvantages of this method include: a large initial contact area on the cone and, as a consequence, a longer heating time required for the molten metal both welded parts. This reduces the efficiency of the process increases the energy consumption.

The known method of flash butt welding of parts made of dissimilar metals with the preliminary preparation of the ends in the form of a wedge protrusion of the one part and the through-hole parallel to the end face of another part [2].

The disadvantages of this method include the need for skilled works that are applicable only to the enterprises of the instrumental profile in serial production.

The objective of the invention is to improve the quality of the welding on the outer belt, due to the simultaneous melting of the metals of the two components in the welding area; limiting the mechanical stresses in the weld due to the redistribution of mechanical loads between the weld seam and butt connection cones; increasing productivity and reducing energy intensity of the process.

This task is achieved by the fact that in the world and perform a ledge and at the end of another part of the groove according to the claimed invention, the protrusion perform at the end of items with high resistivity, and a recess on the end face of the workpiece with a lower specific resistance, while choosing the ratio of the areas of the cross section of the parts in the junction of the conditions of their direct proportionality resistivity of the material of the welded components. In addition, the protrusion and the recess can perform the tapered part. In addition, the protrusion and the recess can perform with a cross section in the form of a polygon.

As a result, the connection has two element mounting: weld on the outer belt and a shrink fit on the cone (Fig.4).

In Fig.1 shows the shape of the ends of parts prepared for welding. Item 1 made of metal with a resistivity R1 [MSM], and item 2 with a resistivity R2 [ASM], with R1>R2. As the protrusion and the recess are cylindrical part L11-2 mm part 1, for orientation when positioned for welding, and cone L13-5 mm for connection to a hot landing. Dimensions L2, L2 part 2 more sizes L1, L1 parts 1 on a given amount of precipitation. In Fig.2 shows a variant of the preparation of the ends of parts.

In Fig. 3 shows the relative path svarochnoye times what specific resistance R2 is less than the resistivity R1 of the metal part 1. The ratio of the densities of currents aligns the electrical power going to heat both parts near the joint, which heats the metal until tender and beginning of precipitation. In the process of precipitation increases the contact area detail 1 detail 2 on the cone. The current density parts 1 decreases, and the heating rate on the approach to the melting temperature, which provides a more uniform heating of the metal. This condition persists until the melting temperature.

The training ends welded components also allows the equipment to weld parts with a diameter of 2-2 .5 times higher than indicated in the technical passport of welding equipment.

Sources of information

1. USSR author's certificate 197793, CL 23 To 11/02, 1967

2. USSR author's certificate 785002, CL 23 To 11/02, 1980

1. Method of butt welding resistance of parts made of dissimilar metals, in which the end of one part perform the ledge, and on the other end part of the recess, wherein the projection performs at the end of items with a large specific Losada section details the junction of the conditions of their direct proportionality resistivity of the material of the welded components.

2. The method according to p. 1, characterized in that the protrusion and recess comply with the tapered part.

3. The method according to p. 1, characterized in that the protrusion and recess comply with section in the form of a polygon.

 

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