Effects of aging temperature on microstructural evolution at dissimilar metal weld interfaces

Multi-technique study of precipitation in the near-fusion boundary region of an aged narrow-gap dissimilar metal weld

“…This redistribution of carbon in the microstructure leads to associated changes in mechanical properties, locally in the affected regions but also for the whole joint. Accordingly, many authors have reported an increase in the micro-hardness in weld metal next to the fusion boundary [5][6][7][8][9][10], which is related to this carbon migration. The magnitude of carbon transport during aging in service conditions was investigated in the present weld and was shown to be strongly correlated to changes in the local mechanical properties [2].…”

“…In previous studies, it was observed that Cr-rich precipitates formed and coarsened in the fusion boundary region. The precipitates were identified as Cr23C6 based upon their TEM diffraction patterns [6,[11][12][13]. Choi et al [14] studied the Cr-rich precipitates in the fusion boundary region between Alloy 152 and A533 Gr.…”