A calibration device and calibration method for testing residual stress by ultrasonic method

Abstract

The invention discloses a calibration device for testing residual stress by ultrasonic method, which is characterized in that it comprises a cylinder with an open upper end and a closed lower end with a cavity inside, and a cover arranged at the open end of the cylinder; the cover It comprises a screw-in part capable of being screwed into the cylinder and a cap (1) arranged at the end of the screw-in part and outside the cylinder. The calibration device of the present invention is not only simple in structure, but also low in cost. The main method is to add hydraulic oil into the cylindrical barrel, then screw the screw-in part into the cylindrical barrel and compress the hydraulic oil, thereby generating force on the outer surface of the cylindrical barrel, and then measure This method of force is used to calibrate the residual stress used in the ultrasonic method, so that the quantitative relationship between the length of the screw-in part of the cover body screwed into the cylinder and the stress generated on the surface of the cylinder can be quantitatively studied in advance, and the detection of the cylindrical material can be realized. Accurate calibration and calibration can reduce the test error, which is suitable for popularization and application.

Description

technical field [0001] The invention relates to a calibration device, in particular to a calibration device and a calibration method for ultrasonic testing of residual stress. Background technique [0002] Higher residual stress may accelerate the crack initiation, expansion, stress corrosion, etc. of the workpiece. For thin-walled workpieces with high stress, it may cause obvious instability wave deformation and seriously affect the dimensional accuracy. In recent years, both academia and industry have invested a lot of research energy on residual stress. The importance of accurate testing of residual stress state as the basis for researching residual stress cannot be overstated. Ultrasonic residual stress testing method has been developed rapidly in recent years. The stress constant K, the basic parameter to ensure the accuracy of ultrasonic residual stress testing, can usually be obtained by uniaxial tensile calibration. For non-planar materials such as cylindrical oil p...

AI Technical Summary

Problems solved by technology

In the process of testing cylindrical materials by ultrasonic method, the refraction angle and propagation path of ultrasonic waves are quite different from those of flat materials, so the calibration results of using plate materials instead of cylindrical materials have large errors

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