时效处理对Cr20Mn18N0.5高氮奥氏体不锈钢组织与力学性能的影响

Effects of Aging Treatment on Microstructure and Mechanical Properties of Cr20Mn18N0.5 High Nitrogen Austenitic Stainless Steel

采用显微组织观察、拉伸试验等方法研究了不同时效处理对Cr20Mn18N0.5高氮奥氏体不锈钢组织及力学性能的影响。结果表明:随着时效温度的增加,试验钢中Cr2N析出相先增加后减少,700℃时效的试验钢中Cr2N析出相数量最多。随着时效时间的延长,试验钢中Cr2N析出相逐渐增加。700℃×12 h时效试验钢,析出物开始向晶粒内部生长,抗拉强度和伸长率分别为823 MPa和52.7%,与固溶态相比,分别下降了4.1%和8.3%。

The effects of different aging treatments on the microstructure and mechanical properties of Cr20Mn18N0.5 high nitrogen austenitic stainless steel were studied by means of microstructure observation and tensile test. The results show that with the increases of aging temperature, the number of Cr2N precipitates increases first and then decreases, and the number of Cr2N precipitates in the test steel aged at 700 ℃ reaches the maximum. With the increases of aging time, the precipitation of Cr2N in test steel increases gradually. The precipitates in the test steel aged at 700 ℃×12 h begin to grow into the grains. The tensile strength and elongation of the test steel are 823 MPa and 52.7%, respectively, which are 4.1% and 8.3%lower than that of the solid solution test steel.