In this study, we focused our attention on microstructure control and improvement of mechanical properties of induction tempering S45C steel using super rapid induction heating system. We examined the effect of tempering time on tensile properties. The tempering temperature was changed in 3 steps, and tempering time was changed in 2 steps. As a result, it was found that the QT steel obtained from super rapid induction tempering had both high strength and high ductility. The super rapid induction tempering is effective to increase the fracture strain and reduction of area. The reason for this phenomenon was explained in that cementite particle of super rapid induction tempering steel became small and dispersed finely in comparison with usual tempering steel. Finally, this paper proposed effective technique to improve mechanical properties of S45C steels.
