ESTIMATION OF THE EFFECT OF RESIDUAL STRESS ON 304 STAINLESS STEEL BASED ON WECHSLER HARDNESS TEST

Abstract

This study applies the indentation strain method, using a high-magnification microscope to examine the indentations created by the Wechsler hardness test. The goal is to determine how residual stress affects hardness measurements in metal materials. Specifically, this research uses a nuclear-grade 304 stainless steel sample as the test subject. By combining mechanical experiments and finite element simulations, the study investigates how tensile residual stress in metal materials impacts the results of hardness tests. The results show that when the residual stress is less than the yield limit of the material, the hardness value of the material decreases with the increase of the residual stress and vice versa. From the experimentation and simulations, it is concluded, with the increase of residual stress, the diagonal length difference of the indentation tends to increase, which is also consistent with the theoretical inference.