GB/T 39520-2020Test method for determination the residual stress of spring by X-ray diffraction (English PDF)

1 Scope

This standard specifies the use of X-ray diffraction principles to detect springs (coil springs, leaf springs and stabilizers, hereinafter referred to as "springs").

The method of sample residual stress, including the source and classification of spring residual stress, X-ray stress test principle and method, instrument, procedure, number

According to processing, test uncertainty and test report.

This standard applies to the residual stress test of springs made of ferrite, pearlite, bainite, martensite and austenitic steels.

Other springs can be used as reference.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this document.

For undated references, the latest version (including all amendments) applies to this document.

GB/T 1805 Spring term

GB/T 7704 Non-destructive testing X-ray stress determination method

JB/T 9394 Non-destructive testing equipment X-ray stress tester technical conditions

3 Terms and definitions

The terms and definitions defined in GB/T 1805 and GB/T 7704 apply to this document.

4 symbols

The following symbols apply to this document.

A. Absorption factor d0.Interplanar spacing of the material in an unstressed state dphiPsi. The distance between the crystal planes in the direction defined by the phi and Psi angles

{hkl}. A family of crystal planes with crystal plane index (hkl) (L1, L2, L3). laboratory coordinate system

LP. Lorentz polarization factor

Z. X-ray penetration depth

beta. Integral width, that is, the ratio of the integrated area to the maximum intensity after the diffraction peak is removed from the background irrelevant to the Bragg diffraction

epsilonphiPsi. strain in the direction defined by the phi and Psi angles

theta. Bragg angle, 1/2 of the diffraction angle 2theta, that is, the angle between the incident X-ray or diffraction line and the diffraction crystal plane

sigma. Normal stress in the direction of phi angle

sigmaii. normal stress component (i=1,2,3) […]