Effects of Hybrid Surface Modification 'PALNIP' of Nitriding and Super Rapid Induction Heating and Quenching on Wear Resistance and Fatigue Strength of AISI1045 and Cr-Mo Steels

摘要

In order to increase fatigue strength and wear resistance of AISI1045 and Cr-Mo steel, a hybrid surface modification "PALNIP"; combination of salt nitrocarburizing and Super Rapid Induction Hardening and Quenching "SRIQ", was developed. Rotating bending fatigue tests, pitting fatigue test and wear tests were performed with special focus on the effects of higher hardness layer and compound layer. The wear resistance and fatigue strength of the steel treated by the above hybrid modification were much higher than those of the steel treated by the single modification. This was because the hybrid surface modified steel had three special characteristics; the compound layer remaining intact even after the induction hardening, the very fine martensite generated through the nitriding and induction hardening, and the high compressive residual stress and deep hardened layer. Therefore, the proposed hybrid modification "PALNIP" is much effective for improving wear resistance and fatigue strength.