Method for measuring residual stress of thin plating layer based on surface ultrasonic waves

Abstract

The invention discloses a method for measuring the residual stress of a thin plating layer based on surface ultrasonic waves. The method comprises the following steps of: setting the working distance between a transmitting probe and a receiving probe; preparing a thin plating layer sample to be measured into a standard stretching member, and performing stress relief annealing; fixing the display time of an initial wave signal; under multiple stress conditions, testing the thin plating layer sample to be measured, and recording the surface ultrasonic wave signal under each stress condition until a macrocrack appears on the thin plating layer to be measured; defining a reference signal, and respectively calculating the time difference between the surface ultrasonic wave signal of the thin plating layer to be measured and the reference signal under multiple stress conditions; fitting an acoustic elasticity formula for describing the relationship between the stress and the time difference according to the corresponding relationship between multiple stresses and the time difference; and calculating the time difference between the surface ultrasonic wave detection signal and the reference signal for the sample to be measured of the thin plating layer with the same thickness and same type as the thin plating layer sample to be measured, and calculating the residual stress value of the sample to be measured by use of the acoustic elasticity formula.

Description

technical field [0001] The invention relates to the measurement field, in particular to a method for measuring the residual stress of a thin coating based on surface ultrasonic waves. Background technique [0002] At present, every year in our country, a large number of scrap steel parts are recycled as scrap steel at the material level, resulting in the waste of resources and energy and the pollution of the environment. Starting from the concept of sustainable development of resources, environment and social economy, the recycling and remanufacturing of waste steel parts is of great significance to energy saving, material conservation, environmental protection and the promotion of coordinated development of social economy and the environment. [0003] Preparing a coating with the required performance on the surface of the workpiece is the most common method to improve the performance of the workpiece and prolong the service life. Therefore, various techniques for preparing ...

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Problems solved by technology

[0006] The purpose of the present invention is to overcome the defect that the existing coating residual stress detection method is only suitable for sampling de

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