Study of Variation in Fracture Location of Electron Beam-Welded Hastelloy C-276 Sheets under Uniaxial Tension

In the present study on the analysis of fractured tensile specimens of welded Hastelloy C-276 sheets, it was inferred that the failure of the weldment depends on the type of intermetallic phases formed in the weld zone (WZ). This failure phenomenon is also influenced by the inclination between the adjacent grains formed in the WZ. For instance, the welded specimens having a lower inter-granular inclination angle (= 39.68°) and containing 47Cr-26Ni-rich precipitate in the WZ were observed to fail from the base metal (BM). The presence of 47Cr-26Ni-rich precipitate provided restriction to the dislocation motion through pinning. On the other hand, the specimen containing 40Ni-27Mo-rich precipitate was observed to fail at the WZ due to decohesion and fragmentation of the precipitates under tension. The relative ease of dislocation motion due to a higher inter-granular inclination angle (= 103.76°) in the WZ also led to the early failure of the weldment. The percent elongation (PE) of the WZ-fractured specimen was lowered by 15% as compared to that of the BM-fractured specimen. The introduction of apparent percent elongation (APE) helped in identifying the zone (BM or WZ) that underwent maximum plastic deformation during the tensile test.