The Behavior of ε‐Carbides and Their Influence on Residual Stress

Abstract

During low‐temperature tempering of wear‐resistant steel, ε‐carbide precipitation can effectively relax residual stress, and its microscopic mechanism is currently unclear. To reveal the stress relaxation mechanism during ε‐carbide precipitation, density functional theory calculations are combined with experiments to explore the ε‐carbide growth behavior and the stress evolution. The results show that ε‐carbide precipitation includes two stages: ε‐precursor formation and ε‐carbide nucleation, and ε‐carbide is in situ nucleated from ε‐precursor matrix. The precipitation‐induced stress relaxation behavior mainly occurs in the early stage of ε‐precursor formation and ε‐carbide nucleation. The early stage of ε‐precursor formation and ε‐carbide precipitation can relax the residual stress to 35.73% and 27.07%, respectively.