Li, W.; Xiao, L.; Walters, L.; Dong, Q.; Ienzi, M.; Sloan, R. High-Temperature Creep and Microstructure Evolution of Alloy 800H Weldments with Inconel 625 and Haynes 230 Filler Materials. Appl. Sci.2024, 14, 1347.
Li, W.; Xiao, L.; Walters, L.; Dong, Q.; Ienzi, M.; Sloan, R. High-Temperature Creep and Microstructure Evolution of Alloy 800H Weldments with Inconel 625 and Haynes 230 Filler Materials. Appl. Sci. 2024, 14, 1347.
Li, W.; Xiao, L.; Walters, L.; Dong, Q.; Ienzi, M.; Sloan, R. High-Temperature Creep and Microstructure Evolution of Alloy 800H Weldments with Inconel 625 and Haynes 230 Filler Materials. Appl. Sci.2024, 14, 1347.
Li, W.; Xiao, L.; Walters, L.; Dong, Q.; Ienzi, M.; Sloan, R. High-Temperature Creep and Microstructure Evolution of Alloy 800H Weldments with Inconel 625 and Haynes 230 Filler Materials. Appl. Sci. 2024, 14, 1347.
Abstract
Alloy 800H stands as one of the few code qualified materials for fabricating in core and out of core components operating in high temperature reactors (HTRs). Welding is a common practice for assembling these components, however, the election of a suitable filler material is essential to enhance the high-temperature creep resistance of Alloy 800H weldments in high temperature applications. In this study, Inconel 625 and Haynes 230 filler material were used to weld the Alloy 800H plates employing the Gas Tungsten Arc Welding (GTAW) technique. The high temperature tensile, creep rupture property, microstructural stability and evolution of the weldments after high temperature exposure were investigated and compared with Alloy 800H. The results showed that the both weldments exhibited enhanced tensile and creep behavior at 760 oC. The creep rupture time of the weldments with Inconel 625 filler and Haynes 230 filler materials was about two and three time longer than that of Alloy 800H base metal when tested at 80 MPa and 760 oC, respectively. Carbides (MC and M23C6) were commonly observed in the microstructure of both the weld and base metals in the two weldments after high temperature creep tests. However, the Inconel 625 filler weldment displayed detrimental δ and Laves phase in the fusion zone and these precipitates could be potential sites for initiating cracks following prolonged high temperature exposure. The study showed that the weldment with Haynes 230 exhibited better phase stability and creep rupture property than the one with Inconel 625 filler material, suggesting its potential as a candidate filler material for Alloy 800H for further investigation. The finding also emphasizes the critical consideration of microstructural evolutions and phase stability in evaluating high temperature materials and their weldments in high temperature reactor applications.
Engineering, Metallurgy and Metallurgical Engineering
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