Analysis on Microstructure of Welded Joint of T92/Super304H Dissimilar Steel

The welded joint of T92/Super304H dissimilar steel was investigated by optical microscopy,scanning electron microscopy,electron probe micro-analyzer and X-ray diffractometer.The results show that the matrix of the welded metal is composed of austenitic cellular dendrite.The precipitates of M23C6 and NbC were also observed in the microstructure of the weld metal.The heat affected zone at the Super304H side consists of austenite and precipitates of NbC,Cu-rich phase and M23C6.The microstructure of the heat affected zone on the T92 side is tempered martensite and M23C6 precipitate.The carbon depleted or enriched zone can not be detected on both sides of the fusing zone.