Method for predicting residual stress of metal plate based on residual stress release warpage

Abstract

Provided is a method for predicting the residual stress of a metal plate based on residual stress release warpage. The residual stress of plates with different thickness is measured by using an X raymethod, a blind hole method, an ultrasonic method, a crack flexibility method or a finite element analysis method. Samples are cut by machining, the release of residual stress causes warpage of the plates, the warpage is measured by using a displacement sensor, and the relation between residual stress and warpage of the plates with different thickness is obtained. A quadratic equation y=a*x<2>+b*x+c is obtained through curve fitting, wherein x is residual stress, y is warpage, and a, b and c are fitting coefficients. The warpage y under a specific line cutting percentage is measured based on the established function relation between residual stress and warpage, and the residual stress is calculated according to the formula x=(-b+ / -the square root of b<2>-4*a*(c-y)) / 2*a.

Description

technical field [0001] The invention relates to a method for predicting the residual stress of a metal plate based on the residual stress release warpage amount. technical background [0002] Aluminum alloy thick plates are widely used in large equipment such as aerospace. In the production process of aerospace aluminum alloy thick plates, in order to improve the mechanical properties of the plates, solution quenching and aging treatment are usually used. High residual stress, because the core is cooled slower than the surface, the surface is compressive stress after final quenching, and the core is tensile stress. The existence of residual stress causes aluminum alloy thick plates to deform during machining into aviation parts, which leads to deformation and failure of parts. In order to reduce the residual stress of the aluminum alloy thick plate, pre-stretching treatment is carried out after solution quenching, and the plastic stretching produced by the pre-stretching p...

AI Technical Summary

Problems solved by technology

Due to the high cost of residual stress test equipment and the harsh test environment, it is not suitable for the control of aluminum alloy properties in industrial production. Therefore, an effective characterization method suitable for the residual stress in the industrial production process of aluminum alloy thick plates is needed.

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