Friction stir welding repair method for threaded hole

Abstract

The invention provides a friction stir welding and mechanical self-locking repair method for a threaded hole, and aims to improve the repair quality and repair efficiency of the threaded hole. The groove is machined in the to-be-repaired threaded hole, so that mechanical self-locking is generated while metallurgical bonding of the filling material and the to-be-repaired area is achieved, and the bearing capacity of the repaired threaded hole is improved through the dual effects of mechanical self-locking and metallurgical bonding. And the adopted filling material is in a circular ring shape, so that the repairing efficiency is improved, and the rigidity requirement of the used equipment is reduced.

Description

technical field [0001] The invention relates to a method for repairing a threaded hole by friction stir welding. Background technique [0002] Threaded connection is a widely used and detachable connection method, which has the advantages of simple structure, reliable connection, convenient assembly and disassembly, etc. It is often used for the connection between metal and metal, metal and non-metal. During the service process of components, under the action of complex alternating loads, wear defects such as thread teeth falling off and hole wall collapse will occur in the threaded connection parts, and these defects will seriously affect the bearing performance of components. Threaded holes are usually processed on the component body, and severe wear of the threaded holes will lead to the scrapping of the whole component, which not only wastes resources but also increases costs. Therefore, it is necessary to repair the wear defect of the threaded hole in time to increase ...

AI Technical Summary

Problems solved by technology

However, since the process parameters have a great influence on the degree of metallurgical bonding between the filling material and the area to be repaired, this poses a challenge to how to ensure effective metallurgical bonding between the filling material and the area to be repaired

When the process parameters such as the rotation speed of the stirring head, the welding speed and the radial pressure of the stirring pin are unreasonable, it will lead to insufficient metallurgical bonding, and once the insufficient metallurgical bonding occurs, the defect of insufficient metallurgical bonding can only be allowed to exist in the In the repair area, under the condition of force, the performance of the repair area will deteriorate rapidly

Secondly, the cylindrical filling material used in the invention patent CN110640295A puts forward higher requirements on the rigidity of the repair equipment, which makes it more difficult to realize the repair of threaded holes

Finally, in order to fully plasticize the surrounding metal and allow the thread cutter to protrude, the repair in the invention patent CN110640295A requires a residence time of 1-300s. If the residence time is not long enough, the metal around the thread cutter will not soften, and the thread cutter will not stretch out under the action of manpower. If it does not come out, the ability of thread processing cannot be realized, but a longer residence time will lead to a decrease in the repair efficiency of threaded holes

Images