研究了马氏体不锈轴承钢经添加氮元素及热处理后的微观组织和力学性能。结果表明,经过相同的热处理后,高氮马氏体不锈轴承钢比没有经过氮合金化处理的马氏体不锈钢具有更高的抗拉强度、屈服强度和硬度,分别提高了20%、26%和21%;同时冲击韧性没有明显降低。组织观察发现,经过氮合金化及热处理后,马氏体不锈轴承钢中的析出碳化物得到了细化。最大碳化物尺寸由25μm降低至5μm,碳化物平均尺寸由882 nm降低至592 nm,碳化物所占面积比例由16.0%降低至2.3%。氮元素的固溶强化和细小析出相的沉淀强化是造成高氮马氏体不锈轴承钢综合性能提高的原因。 The microstructure and mechanical properties of martensitic stainless bearing steel after nitrogen addition and heat treatment were studied. The results show that after the same heat treatment, the high nitrogen martensitic stainless steel bearing steel has higher tensile strength, yield strength and hardness, respectively, than the martensitic stainless steel without nitrogen alloying treatment, respectively, increased by 20%, 26 % And 21%; while no significant decrease in impact toughness. Tissue observation found that after the nitrogen alloying and heat treatment, martensitic stainless steel bearing carbide precipitation has been refined. The maximum carbide size decreased from 25μm to 5μm, the average carbide size decreased from 882nm to 592nm, and the carbide area decreased from 16.0% to 2.3%. The solid solution strengthening of nitrogen element and precipitation strengthening of fine precipitated phase are the reasons that lead to the improvement of comprehensive performance of high nitrogen martensitic stainless steel bearing steel.