A Method for Nondestructive Evaluation of Residual Stress by Ultrasonic Water Immersion

Abstract

The invention belongs to the field of nondestructive testing and relates to a method for nondestructively evaluating residual stress by ultrasonic water immersion. The present invention utilizes the advantages of high ultrasonic longitudinal wave penetration to ensure the response to the residual stress inside the material, overcomes the shortcoming of insufficient penetration depth of the critical refraction longitudinal wave method, and can respond to the residual stress at a depth of 300mm inside the material; the present invention adopts water immersion The method uses water as the coupling agent, which ensures the rapid and flexible movement of the probe, overcomes the shortcomings of the low degree of automation in the measurement of stress by the shear wave method, improves the coupling stability between the probe and the workpiece during measurement, and reduces the temperature caused by changes. Measurement error. Compared with the destructive residual stress measurement method, the present invention can realize the non-destructive detection of residual stress, and the measurement speed is fast, and the two-dimensional distribution map of residual stress can be obtained quickly. Compared with other non-destructive residual stress measurement methods, the measurement depth is the largest, The measurement speed is twice that of other methods, and the measurement cost is less than one-tenth of other methods.

Description

technical field [0001] The invention belongs to the field of nondestructive testing and relates to a method for nondestructively evaluating residual stress by ultrasonic water immersion. Background technique [0002] Many materials require non-destructive measurement of their internal residual stress to meet the requirements of preventing processing deformation and in-depth understanding of material properties. Ultrasonic non-destructive evaluation of material residual stress technology has become one of the available technologies. However, the current ultrasonic residual stress measurement technology has the following two problems: first, the measurement depth of the critical refraction longitudinal wave method is relatively shallow, and the critical refraction longitudinal wave method uses critical refraction longitudinal waves that propagate within an ultrasonic wavelength range below the surface of the material to evaluate the depth of the material. The maximum measurem...

AI Technical Summary

Problems solved by technology

However, the current ultrasonic residual stress measurement technology has the following two problems: first, the measurement depth of the critical refraction longitudinal wave method is relatively shallow, and the critical refraction longitudinal wave method uses critical refraction longitudinal waves that propagate within an ultrasonic wavelength range below the surface of the material to evaluate the depth of the material. The maximum measurement depth is no more than 10mm, which cannot reflect the residual stress inside the material; the second problem is that the detection efficiency of the ultrasonic stress measurement by the transverse wave method is too low, and the ultrasonic residual stress measurement by the transverse wave method requires a special coupling agent with a high viscosity , each measurement position needs to rotate the probe, a single measurement takes a long time, and the probe is difficult to move, and continuous automatic measurement cannot be realized