An Ultrasonic Residual Stress Test Method That Can Correct the Effect of Grain Size Difference

Abstract

The invention discloses an ultrasonic residual stress testing method capable of correcting grain size difference influences and belongs to the field of non-destructive detection of welding residual stress.According to the testing method, a database about the relationships between grain size and longitudinal wave signal decay degree, between grain size and the propagation time of critical refraction longitudinal waves in a zero-stress sample, and between grain size and sonoelastic coefficient is established firstly; during residual stress testing, the longitudinal wave signal decay degree of an area to be tested is determined firstly, then a grain size calculated value is determined according to the decay degree, the propagation time of critical refraction longitudinal waves in the zero-stress elongation sample and the sonoelastic coefficient in the area to be tested are calculated, and finally corrected residual stress can be obtained.By the adoption of the testing method, errors of the sonoelastic coefficient and the propagation time of ultrasonic waves in the zero-stress sample caused by different grain sizes of different welding areas can be corrected, and ultrasonic residual stress testing precision can be improved remarkably.

Description

technical field [0001] The invention relates to an ultrasonic residual stress testing method capable of correcting the effect of grain size differences, and belongs to the field of non-destructive testing of welding residual stress. Background technique [0002] Welding is the most important connection method in industrial production. The quality of welding determines the quality of welding products. The damage of welded joints caused by excessive welding residual stress is the most important welding damage. The non-destructive testing of residual stress of welded joints plays a very important guiding role in optimizing the welding process in production practice. The non-destructive testing methods for residual stress mainly include neutron diffraction method, synchrotron radiation method, magnetic particle method, X-ray diffraction method and ultrasonic testing method. Among them, the neutron diffraction method and the synchrotron radiation method are expensive in equipmen...

AI Technical Summary

Problems solved by technology

The influence of some large microstructure differences on the ultrasonic propagation velocity is even in the same order of magnitude as that of the welding residual stress on the ultrasonic propagation velocity, which seriously affects the test accuracy of the ultrasonic residual stress test method and limits the development of the ultrasonic residual stress test method.

Images