本文研究了碳钢和低合金钢气体软氮化后进行整体淬火复合处理工艺时组织,相组成和氨浓度分布的规律。试验表明,复合处理后可在零件表面形成一层含氮的马氏体,与单纯淬火的含碳马氏体相比,组织细微,亚结构细,位错密度高。含氮马氏体形态有针状和板条状的形态,含氨量较高时为针状;含氨量和含碳量均较低时为板条状。含氮层的淬火组织中有较多的残余奥氏体。 In this paper, the regularities of the distribution of microstructure, phase composition and ammonia concentration in carbon steel and low alloy steel after soft nitriding were investigated. Experiments show that the composite treatment can form a layer of nitrogen-containing martensite on the surface of the part, which has fine structure, fine sub-structure and high dislocation density compared with the pure tempered carbon-containing martensite. Nitrogen-containing martensite morphology acicular and lath-like morphology, high ammonia content for the acicular; ammonia content and carbon content are low when the strip. Nitrogen-containing layer of quenched tissue more retained austenite.