Device for detecting residual stress close to surfaces of metal materials

Abstract

The invention relates to a device for detecting residual stress close to surfaces of metal materials. The device stimulates a critical-refraction longitudinal wave and calculates a stress value according to an acoustic elasticity theory. According to the invention, by reducing contact area between a wedge and a part to be measured, the affect of plate surface distortion to a measurement result can be effectively eliminated; the affect caused by temperature difference can be eliminated by temperature compensation; and therefore, the system is adaptable to tests in more terrible field environments. The system is higher in integration degree, small and exquisite in appearance and convenient to carry.

Description

1. Technical field [0001] The invention designs a near-surface residual stress detection device for steel metal materials. Using ultrasonic longitudinal waves, the detection of residual stress near the surface of metal components can be realized. 2. Background technology [0002] The existing residual stress measurement techniques mainly include pinhole method and X-ray diffraction method. The small hole method has higher measurement accuracy, but this is based on the premise of damaging the surface state of the material. In this method, the surface must be polished before testing, which will undoubtedly produce residual stress, and the strain gauges are cumbersome to paste, which cannot achieve real-time testing. The X-ray diffraction method is mainly used in non-destructive testing. Although this method has been marketed, it has radiation to the human body, and the test time is long, so it cannot be tested on-site. [0003] Although a lot of research has been done on th...

AI Technical Summary

Problems solved by technology

In this method, the surface must be polished before testing, which will undoubtedly generate residual stress, and the strain gauges are cumbersome to paste, which cannot achieve real-time testing

The X-ray diffraction method is mainly used in non-destructive testing. Although this method has been marketed, it has radiation to the human body, and the test time is long, so it cannot be tested on-site.

[0003] Although a lot of research has been done on stress detection using ultrasound, it cannot meet the needs of on-site testing due to unreasonable structural design, many interference factors, and poor repeatability.

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