中文摘要：

针对Mn18Cr18N钢护环锻件多火次锻造后晶粒易长大的问题，研究了不同加热条件对其晶粒尺寸的影响，同时进行了二火次小试样锻造验证。结果表明：锻件的晶粒尺寸具有一定的遗传性，当再加热温度为1100℃、保温5h以内，或者在1050℃长时间再加热的情况下，均未发生晶粒明显长大现象；该钢晶粒长大模型为

英文摘要：

In order to solve the problem of grain growth for the Mn18Cr18N retaining ring steel during the multi-heating hot forging process, the effect of heating condition on grain size was investigated. The two-heating forging test had also been verified with small samples. The results show that the grain size of forgings bad a certain hereditary, and the grain size didn＇t dramatically grow when the forging reheated at 1 100 ℃ for less than 5 h or 1 050 ℃ for longer time. And the grain growth mode of the steel was