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摘要：
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采用数值模拟和工艺实验方法，研究了Mn18Cr18N高氮奥氏体不锈钢在单道次和多道次热压缩工艺过程中的微观组织演变及其对力学性能的影响。结果表明，总变形率均为60%的情况下，不同工艺流程获得的内部组织和力学性能有明显的区别。采用单道次大变形工艺，大变形区得到细小的再结晶晶粒组织，较少量的高温铁素体呈短棒状分散在原始晶界上，综合性能较好；采用道次间隔为5 s的较短时间的多道次压下量均等的小变形工艺，再结晶晶粒更加细小，但是再结晶体积分数较低，变形和组织的不均匀性显著，高温铁素体呈条状断续分布在原始晶界上，强度较高、塑性较差；采用在道次间1100 ℃保温和延长道次间隔时间为5 min的多道次压下量均等的小变形工艺，坯料整个截面上可以获得细小均匀的再结晶晶粒组织，极少量的高温铁素体呈颗粒状弥散分布在晶界上，强度高、塑性好。
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Microstructure evolution and its influence on mechanical properties during the single-pass and multi-pass hot compression processes of Mn18Cr18N high nitrogen austenitic stainless steel were investigated by numerical simulation and experimental methods. The results show that internal microstructures and mechanical properties obtained by different process routes under the total reduction rate of 60% are obviously different. For the single-pass and large deformation process, the fined recrystallized grain microstructure is obtained in the large deformation area, and a small amount of high-temperature ferrite disperses on the original grain boundaries with short rod shape, which has better comprehensive performance. However, for the small deformation process with equal reduction of multiple passes in a short time with the pass interval time of 5 s, the recrystallized grains are smaller, the recrystallization volume fraction is lower, the unevenness of deformation and microstructure is significant, and the high-temperature ferrite is distributed intermittently on the original grain boundaries with strip shape, which causes high strength and poor plasticity. Furthermore, for the small deformation process with equal reduction of multiple passes at holding temperature of 1100 ℃ between passes and extended pass interval time of 5 min, the fine and uniform recrystallized grain structure is obtained on the whole section of billet, and a very small amount of high-temperature ferrite disperses on the grain boundaries with particle shape, which has high strength and better plasticity.
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基金项目：
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国家自然科学基金资助项目（51575372）
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作者简介：
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田继红（1971-），男，博士研究生，副教授，E-mail：tykdtjh@126.com；通讯作者：陈慧琴（1968-），女，博士，教授，E-mail：chenhuiqin@tyust.edu.cn
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