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In the current work the metallurgical and tensile properties of the weld joints of alloy C-2000 were investigated. Welding technique employed in this study is Tungsten Inert Gas Welding (TIG) and Pulsed Current Tungsten Inert Gas (PC-TIG) welding with autogenous mode and Ni-Cr-Mo rich ERNiCrMo-10 filler wire. The results show that PC-TIG weldment obtained the refined microstructure compared to the TIG weldment. Energy dispersive spectroscopy (EDS) showed the extent of Cr segregation was observed in all the weldments. PC-TIG welding shows reduced segregation compared to the corresponding TIG. X-ray diffraction (XRD) corroborated the existence of Ni3Cr2 phases in the weld fusion zone. Tensile test results show the PC-TIG weldment obtained marginally higher tensile properties comparing over the corresponding TIG weldment. The strength of the weldments is inferior in all cases in comparison to base metal.

This research work describes the effect of microsegregation, microstructure and tensile strength of the Hastelloy X weldment produced by keyhole plasma arc welding (K-PAW). Weld joint was obtained in a single pass without the addition of filler wire. The significant results obtained in this research work are (i) fine equiaxed dendrite was detected in the weld centre due to lesser heat input (HI) along with the faster solidification attained in K-PAW (ii) The existence of secondary precipitates in the interdendritic boundary was identified by the scanning electron microscope (SEM) analysis (iii) Energy dispersive X-ray spectroscope (EDS) revealed the Cr and Mo microsegregation in interdendritic boundary of the weld zone (iv) X-ray diffraction (XRD) analysis confirmed the Mo-rich P phase and Cr-rich M23C6 phase. The observed tensile strength of weldment is 6.14 % inferior to base metal.