提高1Cr14Co14Mo5不锈钢韧性的热处理工艺研究

针对因材料韧性不足导致的滚珠丝杠端头脆性断裂失效问题，开展马氏体沉淀硬化型不锈钢1Cr14Co14Mo5的改进研究。基于局部成分调整的1Cr14Co14Mo5不锈钢，将原有固溶+时效热处理工艺进行了调整，尝试利用循环相变热处理细化奥氏体晶粒的微观机制，获得细化的板条状马氏体组织，以提升材料的塑韧性。组织和性能结果显示，固溶温度由1000℃升高至1100℃可有效提高材料冲击韧性；3~4次的循环相变热处理能有效细化晶粒，晶粒平均尺寸小于10 μm，可使材料的冲击吸收能量（KU2）由20.2 J提高至60 J以上，同时断裂韧性值略有上升。 

Study on Heat Treatment Process for Improving the Toughness of 1Cr14Co14Mo5 Stainless Steel

In view of the brittle fracture failure of the end of ball screw caused by insufficient material toughness, this paper carries out the improvement research of martensitic precipitation hardening stainless steel 1Cr14Co14Mo5. Based on the local composition adjustment of 1Cr14Co14Mo5, the study adjusts the original solid solution + aging heat treatment process, that is, the microscopic mechanism of the austenite grains is refined by cyclic phase transformation treatment, to obtain a refined lath martensite structure, and thus to enhance the plasticity and toughness of the material. The microstructure and performance results show that increasing the solution temperature from 1000℃ to 1100℃ can effectively improve the impact toughness of 1Cr14Co14Mo5. 3~4 times of cycle phase transformation treatment can refine the grains and the average grain size is less than 10μm, which can improve the impact toughness KU2 of the material from 20.2 J to more than 60 J and can slightly increase the fracture toughness K1C value.