X線による金属材料の残留応力に関する研究 : 炭素鋼に熱処現を行なったときの残留応力について

抄録

In the case of measurement of residual stress by means of X-rays, there remains a question whether 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 appeared in the specimens was measured by both the X-ray method and the mechanical method, and the results were compared. Obtained results are summarized as follows : 1. The scattering of the stress values obtained by means of X-rays is less than 1 kg/mm² by using the sin² ψ method. 2. The residual stress on the surface is not uniform and varies from place to place of the surface. 3. 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 electro polishing method. However, if such method of surface treatment which raises the selective corrosion as etching by nitric acid is used, the relief of surface stress affects the measured value of residual stress.