Optimizing the surface condition of M50 steel by nitriding treatment to improve the wear resistance
摘要
The influence of nitriding treatment on the microstructure evolution and wear resistance of M50 steel was analyzed using optical microscopy, scanning electron microscopy, X-ray diffractometer, hardness testing and friction, and wear tests. Results show that ε-Fe2-3N and γ'-Fe4N phases were formed on the surface of M50 steel after nitriding treatment. At nitriding temperatures of 470, 490, and 510 °C, the depth of the compound layer was 2.6, 3.5, and 4.5 μm respectively, and the size of the vein microstructure tended to increase. With the increase of the nitriding temperature, the surface hardness and depth of the nitriding layer of M50 steel increased, and the high-hardness area at 490 °C accounted for a large proportion of 69%. The hardness of the core gradually decreased, which is related to the increase in the amount of precipitated carbides. After nitriding treatment, the wear resistance of M50 steel was increased by more than 50%. With the increase of nitriding temperature, the wear resistance first increased and then decreased. The wear resistance of N490 was the best, and the wear resistance of N510 was reduced by cracks and spalling on the wear surface.