An Error Correction Method for Ultrasonic Measurement of Welding Residual Stress

Abstract

An error correction method for ultrasonic measurement of welding residual stress. The steps are as follows: A. Take the base metal plate of the welding test piece to be tested to make welding test plate one and welding test plate two; B. Take the arc starting section from the welded welding test plate. zone sample, stable zone sample and arc closing zone sample, and subdivide each sample according to structural differences, and mark the welding characteristic points; C mark the welding characteristic points at the corresponding positions of the welding test plate 2, and weld Collect the thermal cycle curve from the welding characteristic points of the post-welding test plate 2; D. Prepare the thermal simulation block according to the thermal cycle curve. E. Determine the residual stress based on the residual stress values ​​measured by the ultrasonic method and the cutting method of the base metal small piece and the thermal simulation block. Correction value; F corrects the residual stress measurement value of ultrasonic measurement according to the residual stress correction value to obtain the accurate residual stress value of the weldment to be tested. This method can correct errors caused by differences in microstructure between the base material and the area to be measured, and significantly improve the accuracy of ultrasonic testing of residual stress.

Description

An Error Correction Method for Ultrasonic Measurement of Welding Residual Stress technical field The invention relates to an error correction method for correcting the error of ultrasonically measured welding residual stress caused by the microstructure difference between a test area and a zero-stress calibration block, and belongs to the field of non-destructive testing of welding residual stress. Background technique With the rapid development of China's high-speed train rail transit, welding is a key technology in rail transit, and the quality of welding also determines the quality of high-speed train vehicles to a certain extent. The level of welding residual stress is an important criterion for evaluating welding quality, because welding residue The damage caused by stress is the main reason for the damage of welded joints, so the rapid, efficient, non-destructive monitoring and evaluation of welding residual stress level has great industrial significance. The X-ray ...

AI Technical Summary

Problems solved by technology

This process does not consider the change of ultrasonic velocity caused by the difference in microstructure composition between the weldment to be tested and the base metal, so there is a certain error between the final residual stress and the actual residual stress

This error greatly reduces the accuracy of the ultrasonic method to measure the residual stress, which greatly limits the application of the ultrasonic method in the residual stress test