X-Ray Investigation on the Residual Stress of Metallic Materials : On the Residual Stress in Carbon Steel Caused by Thermal Stress

Abstract

In measurements of residual stress by means of X-rays, there remains a question whether or not the stress measured by X-rays represents the macroscopic residual stress itself. In the present study, carbon steel plate specimens were heat-treated and the residual stress appearing in them was measured by both the X-ray method and the mechanical method, and the results were compared. The macroscopic residual stress in carbon steel caused by thermal stress can be accurately measured using the X-ray method when the specimen surface is treated by the electropolishing method. However, if such method of surface treatment which causes selective corrosion as etching by nitric acid is used, the relief of surface stress affectes the measured value of residual stress.