650℃时效不同时间后Super304H钢的显微组织

摘要

利用光学显微镜、扫描电子显微镜、X射线衍射仪和透射电镜等研究了Super304H钢在650℃时效不同时间后的显微组织。结果表明：500h内时效后Super304H钢的组织均为奥氏体和析出相，析出相主要由Nb（C，N）、富铜相和M23C6组成，而供货态没有M23C6；在时效初期析出相的析出速率相对较快，300h后趋于稳定；随时效时间延长细小颗粒状Nb（C，N）和富铜相没有明显长大，M23C6的形态由细条状逐渐向链状、块状转变。%The microstructure of Super304H steel after aging at 650℃ for different times was investigated by means of optical n-ficroscopy, scanning electron microscopy, X-ray diffractometer and transmission electron microscopy. The results show that the microstructure of Super304H steel after aging for 500 h consisted of austenite phase and precipitate phase, which included Nb（C,N）, M23 C6 and Cu-rich phase. However, M23C6was not found in the as-received Super304H steel. The precipitate rate of precipitate phase was relatively fast at the initial stage and became stable after 300 h. With increase of aging time, fine Nb（C,N） particles and Cu-rich phase had not grow obviously. The morphology of M23 C6 changed from fine lath-like to chainqike and bulk.