长时运行T91/G102焊接接头显微组织变化研究

对长时运行前后T91/G102异种钢焊接接头的金相组织变化进行了分析研究。结果表明,长时运行对T91侧的显微组织影响不大,而对G102侧的显微组织有明显的影响:长时运行后,G102侧母材原有的板条状贝氏体特征已基本消失,代之而来的是再结晶晶粒的形成以及碳化物的聚集长大;G102侧正火区原有的细小粒状贝氏体特征仍然保持,但有一定程度的回复;G102侧过热区发生了回复和再结晶,有更多的小晶粒形成,且原组织的晶界更加清晰。焊缝区在经过长时运行后板条状组织减少,等轴状组织增多。长时运行后,背火面的组织比向火面细小,并且在背火面焊缝的某些部位观察到了明显的柱状晶组织。

Study on Microstructure Changes of T91/G102 Welded Joints after Long-running

After a long time running,the microstructure changes of joints welded with T91/G102 dissimilar steel have been analyzed. The results show that the long-running has little effect on the microstructure of T91 side,but visible effects on the microstructure of G102 side:after a long time running, in G102 side,the original lath-shape bainite features in base metal disappear, recrystal grain forming and carbide accumulating and growing,original small granular bainite features normalizing zone in G102 side remaine except a certain extent of recovery; recovery and recrystallization take place in overheating zone, the smaller grains form, and the original grains boundaries become more clearly.In welding zone the lath-shape microstructure reduces, and equiaxed microstructure increases.The microstructure on the other side away from the fire is smaller than that of the side closed to the fire, and the obvious columnar grains form in some parts of the weld zone on the side away from the fire.