Detection of Gradient Residual Stress in Welding of Railway Bogie Frame Based on Ultrasonic Method

Ultrasonic critical refraction longitudinal wave method uses the characteristics of refraction critical refraction longitudinal wave propagating along the surface of the component, and the residual stress level in the depth can be detected and determined by sensors of different frequencies. This paper uses this technology to study the residual stress distribution levels of different depth gradients of railway bogie frames, and confirms the feasibility of using the LCR wave method to detect gradient residual stresses. The results show that with the continuous increase of the frame depth gradient, The stress level shows a trend of first increasing and then decreasing, and the residual stress value is the largest at the depth of 0.65mm on the surface.