, Beijing Machinery and Electricity Institute Co Ltd (BMEI)
In this paper, the wear resistance and antifriction of epsilon phase layer and diffusion layer of gas nitrided D2 steel and M2 steel have been studied. The changes m wear mechanism of epsilon phase under the load from 20N to 200N are analysed. When the load is lighter than 100N, it is mainly oxidizing wear on friction surface. The adhesion, peeling off and abrasive wear appear on friction surface while the load is heavier than 150N. The epsilon phase on nitrided D2 steel surface can reduce oxidizing wear and adhesion, and delay abrasive wear. The friction coefficient of D2 steel can be reduced by 19%, and the wear resistance can be increased 200% to 300% by the epsilon phase layer on nitrided surface.