Method for eliminating residual stress in welding by ultrasonic peening and use thereof

Abstract

The invention relates to a method for eliminating residual stress in welding by ultrasonic peening and use thereof. The method is implemented mainly by using an ultrasonic peening device which comprises an ultrasonic wave generator, an acoustic system and a machine frame, wherein the ultrasonic wave generator and the acoustic system are arranged on the machine frame; the acoustic system has an energy transducer; the ultrasonic wave generator converts 50Hz power frequency alternating current power in a grid into ultrasonic frequency 20kHz alternating current power for exciting the energy transducer of the acoustic system; and the energy transducer of the acoustic system converts electric energy into mechanical vibration at the same frequency and transmits the ultrasonic frequency mechanical vibration to a weld joint in a workpiece at the temperature of 400 to 800 DEG C, so that a deep enough plastic deformation is formed on the surface of the weld joint part. The method which adopts a simple process has high-efficiency, energy-saving and environmentally-friendly characteristics and other characteristics in the elimination of the residual stress generated in a repair and welding process of a cast steel piece such as a swing bolster and a side frame. In addition, the method improves the stress distribution and fatigue strength of the weld joint.

Description

technical field [0001] The invention relates to a method for eliminating residual stress in welding, in particular to the application of a method for eliminating residual stress in welding by ultrasonic impact in the defect repair of cast steel side frames and bolsters of railway wagons. Background technique [0002] According to the requirements of the "Regulations for the Factory Repair of Railway Freight Cars", tempering treatment or local stress relief treatment is required after welding and repairing the defects of the key parts of the cast steel bolster and side frame of the railway freight car bogie. However, because the overall tempering treatment has high requirements on equipment conditions, excessive energy consumption, long maintenance cycle, and adverse effects on other processing surfaces, it is rarely used in my country's railway vehicle repair industry at present, and more local ones are used. Ways to relieve stress. [0003] Local stress relief treatment usu...

AI Technical Summary

Problems solved by technology

At present, the bogie bolsters and side frames of railway freight cars are mainly made of B-grade cast steel and B+ grade cast steel, all of which have a high tendency to cold cracking. The effect of stress treatment is not good, which can easily cause delayed cracks (cold cracks) and fatigue fractures in defective welding parts, which will eventually lead to failure of parts and bring great safety hazards to railway transportation