Fatigue Properties of Quenching and Tempering Steel Using Super Rapid Induction Heating

Abstract

The mechanical properties of steels are known to be improved by grain refinement and by smaller and more finely dispersed cementite particles. Super-rapid induction tempering can achieve smaller and more finely dispersed cementite particles, and super-rapid induction quenching can improve grain refinement. In this study, we investigated the fatigue properties of carbon steel treated by induction quenching and tempering using a super-rapid induction heating technique. Hollow test specimens were fabricated to observe the mechanical properties of the structure obtained by induction heating. Based on our observations, in the finite-life region, no difference was found between tempering conditions for each hardness value, but a transition to longer life due to differences in quenching conditions was observed. In addition, no clear grain refining effect was found in the fatigue limit of induction-quenched steel in the range of the quenching conditions of this study. However, a delay effect due to grain refinement was recognized at the initial stage of crack growth from the consideration of the crack growth rate of induction-tempered steel.