2017 Volume 103 Issue 4 Pages 194-200
When JIS-SUJ2 steel is hardened by induction heating, high temperature austenitizing is applied in order to achieve high productivity. In this case, SUJ2 is quenched from the single-phase austenite zone. As a result, the properties of SUJ2 may be different from the conventional furnace process involving SUJ2 quenched from the two-phase austenite / cementite zone. In this study, we experimentally investigated the relation between the amount of undissolved carbide, austenitizing temperature, and duration. Additionally, we developed a prediction formula for undissolved carbide in the single-phase austenite zone. The formula is consists of the Arrhenius equation and the Kolomogorov-Johnson-Mehl-Avrami equation. Subsequently, the effect of austenitizing temperature and amount of undissolved carbide on hardness, retained austenite content, prior-austenite grain size, and martensite block size were investigated.