The effect of plasma nitriding on the fatigue behavior of DIN1.2210 cold work tool steel

In this research, the effects of plasma nitriding parameters including temperature and time on the microstructures and fatigue strengths of quenched and tempered DIN 1. 2210 cold work tool steel were investigated. The microstructures of the base material and nitrided layer were examined in details by optical microscopy and X-ray diffractions. Micro-hardness measurements were used to determine surface hardness and case depth. A rotating bending fatigue test machine was employed to obtain the fatigue strengths. The results indicated that plasma nitriding considerably increases the micro-hardness and fatigue strength depending on the case depth. The maximum fatigue strength was attained for Plasma nitriding of samples at 550 °C for 6 hours which increased the fatigue life Fe4N and ε: Fe3N: ׳ by about 67%. It was obtained that, the compound layer of the treated samples consisted of γ Fe4N to ε: Fe3N increased by increasing treatment temperature.: ׳ phases which Proportion of γ.