前言气体碳氮共渗是近年来发展较快的一种表面硬化工艺.一些齿轮类零件以碳氮共渗代替渗碳处理后,不仅减化了生产工序,降低了零件的热处理变形,而且提高了产品的耐磨性和接触疲劳性能。但是在镍铬钢齿轮类零件的生产中有时发现部分产品的渗层中存在粗大的片状马氏体。这种粗大组织在原渗碳层中是不曾出现的.由于粗大的高碳马 Preface Gas carbonitriding is a surface hardening process developed rapidly in recent years.After some gear parts replaced carburizing treatment, not only reduce the production process, reduce the part of the heat treatment deformation, and improve The product’s wear resistance and contact fatigue performance. However, in the production of nickel-chromium steel gear parts, it is sometimes found that some of the products have coarse flaky martensite in the coating layer. This coarse tissue did not appear in the original carburized layer due to the thick, high-carbon horse