Investigation of induction hardening on heat-treated EN8 steel by alternately timed quenching process

Abstract

EN8 steel is mostly used for high-strength applications such as axles and crankshafts in vehicles, as well as nuts, gears, and studs. In this work, numerous pre-heat treatments such as annealing, normalizing, hardening, and tempering were performed on EN8 steel. Following the completion of all pre-heat treatment steps, the samples are surface hardened by induction hardening with an alternatively timed quenching approach. A Vicker hardness testing equipment was used to determine the surface hardness of pre-heat treated induction hardening samples. The results show that the normalizing with hardening and tempering sample has a greater surface hardness than the normalized and annealed samples. On the induction hardening samples, case depth was also assessed. The microstructure of the surface hardened samples were examined using an optical microscope. The normalizing with hardening and tempering sample has the highest grain size numbers and martensite needle size.