Effects of M 23C6 on the High-Temperature Performance of Ni-Based Welding Material NiCrFe-7

Effects of Boron on the Microstructure, Ductility-dip-cracking, and Tensile Properties for NiCrFe-7 Weld Metal

“…Previous research [49] reported that DDC is initiating at the M 23 C 6 /γ interface at GBs and then propagates along GBs.…”

“…Researchers have proposed a variety of mechanisms of DDC, including impurity elements embrittlement, such as the segregation of S, P and other impurity elements at GBs, causing the loss of GBs ductility, thereby leading to DDC [17][18][19][20] , GB sliding [14,[21][22][23][24][25] , and precipitation-induced cracking (PIC), such as M 23 C 6 PIC [49] . In essence, DDC is caused by GB embrittlement [49] , and elements segregation at GBs and precipitates along GBs would affect GB embrittlement and DDC.…”

“…In essence, DDC is caused by GB embrittlement [49] , and elements segregation at GBs and precipitates along GBs would affect GB embrittlement and DDC.…”

“…Reference source not found.(d)). DDC initiates at the incoherent M 23 C 6 /γ interface, because the incoherent M 23 C 6 /γ interface has weak interface strength and higher stress concentration [49,[55][56][57] . Together with the thermal and solidification stresses induced during welding, the incoherent M 23 C 6 /γ interface is prone to crack initially, which exacerbates DDC in NiCrFe-7 alloy at elevated temperatures.…”

Effect of Nb and Mo on the Microstructure, Mechanical Properties and Ductility-Dip Cracking of Ni–Cr–Fe Weld Metals

“…Ductility-dip cracking is a solid-state cracking phenomenon, which often occurs along grain boundary in austenitic alloys, superalloys or copper alloys at elevated temperature [7]. Due to the small size of the crack, DDC is usually hard to be detected by the conventional nondestructive examination [8]. A number of factors have been reported to contribute to the DDC initiation and propagation, such as welding processes, the grain boundary orientation relative to the applied strain, weld metal chemical composition (interstitial element content and impure element segregation in the grain boundaries), grain boundaries sliding and dynamic recrystallization [9][10][11][12][13][14][15].…”