Investigation of Metallurgical, Mechanical Properties of Hastelloy X by Keyhole Plasma Arc Welding Process 2019-28-0152
This research work studies effect of microsegregation, microstructure and tensile strength of the Hastelloy x weldment produced by plasma arc welding (PAW). Weld joint was obtained in the 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 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 MoNi4 (P) phase and Cr-rich M23C6 phase. The observed tensile result of weldment is inferior to base metal. The development of secondary precipitates in the weld zone affected the tensile properties of the weld joint.