Prediction of Tempering Effect on Jominy Hardenability Curve

Tempering process improves the toughness of quenched steel by decreasing hardness due to recovery and recrystallization of martensite. Most of the tempering mathematical models derive tempering parameter using Holloman-Jaffe formulation and estimate empirical parameters of an alloy with known chemical composition as a function of tempering time and temperature to de-rate Jominy curve for the effect of tempering time and temperature. In this study, composition dependent tempering parameters are utilized to estimate Jominy curve as a function of tempering time and temperature. Estimated Jominy curves are utilized to predict hardness depth profiles in direct hardened components with simple geometries. Predicted results are compared with the available tempered hardness depth profile.