EXPERIMENTAL STUDY ON THE INFLUENCE OF VACUUM CARBONITRIDING PROCESS FOR 20Cr2Ni4A STEEL

摘要

20Cr2Ni4A steel is a kind of high quality steel mainly used for manufacturing high-duty gears in the world. The high-duty gear with good performance must have wear and fatigue resistance properties. In order to get the good properties, the high-duty gear needs a high hardness gear surface and a good hardness gradient along the depth direction. In this paper, the samples were designed and a vacuum carbonitriding process was put forward to improve the surface hardness of parts for 20Cr2Ni4A. The process contained carbonitriding, quenching, cryogenics, and tempering process. The surface hardness and hardness gradient of carbonitrided samples were measured and the good microstructure was gained. The surface hardness is 67.5HRC and the case depth is 1.2mm.