Measurement of Residual Stress in Weldments With X-Ray Diffraction Method (Report 1)

Measurement of Micro and Macro Residual Stress

Abstract

In the measurement of residual stress in weldment carried out with use of K_α doublet diffraction, it is often difficult to determine the position of the diffraction peak exactly so far, because of the component lines of the doublet spaced so closely and of the their broadening occurring often in welded specimens. Here a method is presented to alleviate the difficulty, where the double diffraction patterns are separated to their single component profiles by means of a simple numerical calculation. While it facilitates the more exact determination of the diffraction peak and therefore of the macro scopic residual stress level, it facilitates the quantitative determination of the broadening of the diffraction profiles with a reasonable precision, too. Thus it becomes possible to draw into account the problem of estimating microscopic residual stress level therefrom, and therefore a mathematical scheme possibly useful for the practical analysis of experimental results and for the physical interpretation is presented also.