Effect of Austenite Grain Size on Mechanical Properties in Spring Steel Austenitized, Quenched and Tempered by Induction Heating

Abstract

It was clearly shown in the previous paper that Induction Heating Quenched and Tempered (IHQIHT) Si-Cr spring steel (SUP12) showed superior mechanical properties to those of conventional Furnace Heating Quenched and Tempered (FHQFHT) material.
So, in order to clarify the effect of grain refining by Induction Heating austenitizing and Quenching (IHQ) for the superior mechanical properties of IHQIHT material, the relation between austenitizing conditions and both grain size and mechanical properties were investigated.
(1) Grain refining by IHQ is effective for the improvement of ductility, toughness, resistivity to delayed fracture, and fatigue life.
(2) Short-time heating as well as rapid heating for Induction Heating austenitizing are effective for grain refining and toughening.
(3) However, Induction Heating Tempering (IHT) as well as grain refining by IHQ has favorable influence on superior mechanical properties of IHQIHT material.