固溶处理对316LN不锈钢晶粒长大及力学性能的影响

Effects of Solution Treatment on Grain Growth and Mechanical Properties of 316LN Stainless Steel

采用Zaiss Imager金相显微镜观察微观组织形貌,研究了316LN奥氏体不锈钢固溶处理后晶粒尺寸变化及力学性能的变化。结果表明：固溶温度越高,保温时间越长,晶粒长大速度越明显,且保温时间对晶粒长大的影响要大于加热温度。初始晶粒度为2.5级时,加热至1050℃和1070℃保温5 h以上,晶粒度不满足核电主管道要求;硬度值随加热温度升高和保温时间延长呈现逐渐下降的趋势。

The grain morphology was observed by Zaiss Imager metallographic microscope. The changes of grain size and mechanical properties of 316 LN austenitic stainless steel were studied after solution treatment. The results show that the higher the solution temperature is, the longer the holding time is, the more obvious the grain growth rate is, and the effect of the holding time on the grain growth is greater than the heating temperature. When the initial grain size is 2.5, heating to 1050 ℃and 1070 ℃ and insulating for more than 5 h, the grain size does not meet the requirements of nuclear power pipeline. After solution treatment, the hardness value tends to decrease with the increase of heating temperature and the holding time prolonging.