通过对实际电厂运行的T91钢进行金相观察、扫描电子显微镜(SEM)分析,从微观组织变化查看T91钢长期高温环境下的老化状况,同时对供货态的T91钢进行研究作为对比.在定量金相法的数据基础上,得到了T91钢扩散速度控制的长大动力学方程.结果表明:T91钢经过长时间服役后,碳化物颗粒在晶界处发生聚集,同时颗粒逐渐粗大,使得晶内碳化物数量减少,强化效果降低. Through the metallurgical observation and scanning electron microscopy (SEM) analysis of the T91 steel running in the actual power plant, the aging status of the T91 steel under the long-term high temperature environment is observed from the microstructure changes. At the same time, the research on the T91 steel supplied in the power plant is taken as a comparison. Based on the data from the quantitative metallographic method, the kinetic equation for the growth kinetics of T91 steel is obtained. The results show that the carbide particles aggregate at the grain boundaries after prolonged service, Reduction of the amount of carbides, strengthening the effect of reduced.