对600℃保温不同时间后的钢板组织进行透射电镜观察,见图4.11。经过600℃保温15、30 min后耐火钢中还存在板条状马氏体。随着回火保温时间的延长,马氏体板条状特征逐渐弱化,保温时间为120 min时基本观察不到马氏体形貌。
The structure of the steel plate after holding at 600℃ for different time was observed by transmission electron microscope, as shown in Figure 4.11. Lath-shaped martensite still exists in refractory steel after heat preservation at 600℃ for 15 to 30 minutes. With the extension of the tempering holding time, the martensite lath characteristics gradually weakened, and the martensite morphology was basically not observed when the holding time was 120 min.