Abstract
During carburization, the surfaces of the steel parts are subjected to a high carbon potential atmosphere. During the process, carbon is absorbed and diffused into the steel increasing the carbon concentration near the surface and also creating compressive residual stresses. Carburizing is followed by quenching process to form Martensite which brings high hardness and strength, but low ductility and toughness. A tempering process is applied to increase the toughness, ductility of the parts after quenching. During tempering, tempered Martensite forms with precipitation of carbides. Both temperature and time determine the evolution of the microstructure. In the present work, the effects of tempering on the hardness profiles in quenched and tempered carburized steels are experimentally investigated and analyzed using the Holloman-Jaffe Parameter.
