Effect of initial metallurgical conditions on induction hardening process on UNI EN 42CrMo4 shafts

In industrial practice, heat treatment companies are usually required to perform induction hardening on parts with different metallurgical supply conditions resulting from different heat treatment routes previously applied. As a result, understanding the effect of material supply conditions on the induction hardening process parameters is of great interest for heat treatment companies. This knowledge enables the proper adjustment of process parameters, ensuring optimal outcomes and consistency across diverse material conditions. In this study, shafts manufactured in UNI EN 42CrMo4 steel were subjected to induction hardening treatment starting from different supply conditions. The study focuses on two distinct case studies: center dot Case study 1 investigates the influence of different preliminary heat treatment routes (normalizing, quenching and tempering); center dot Case study 2 explores the effect of repeated induction hardening, namely the hardening on a part that has been already hardened previously.