Method for nondestructive measurement of residual stress field in metal plate through ultrasonic waves

The invention belongs to the field of nondestructive testing and relates to a method for nondestructive measurement of a residual stress field in a metal plate through ultrasonic waves. The method for nondestructive measurement of the residual stress field in the metal plate through the ultrasonic waves is beneficial to conducting nondestructive evaluation on the residual stress in the metal plate. The single-time measuring time of the method is only about 20 seconds and is dozens of times less than the single-time measuring time of a traditional X-ray residual stress measuring method, and the detection speed is high; meanwhile, the measurement depth in the method is adjustable, the maximum depth can reach 3mm and is dozens of times that of the measuring depth in the X-ray measuring method, and thus the measuring depth is large. The method is provided for measuring large-range residual stress distribution inside the plate, and a three-dimensional diagram or a contour map of the residual stress distribution can be obtained. The cost for the single-time measuring of the method is dozens of times less than that of the X-ray measuring method, obvious economy is achieved. The method is free of radioactivity and is safer compared with the X-ray measuring method.