Publication

Abstract : Alloy C-276 prone to the formation of Topologically Closed Phases (TCP) at the end of the solidification. The formation of the TCP phases is known to the elemental segregation of Mo and W at the end of the solidification. The present research investigated the possibility of suppressing the elemental segregation by employing current pulsing technique. The weldment was fabricated by Pulsed Current Gas Tungsten Arc (PCGTA) Welding mode. The weld joint was studied with respect to microstructure, microsegregation and mechanical properties. Optical and Scanning electron microscopy were employed to study the microstructural changes in the fusion zone. The extent of microsegregation was studied by Energy-Dispersive Spectroscopy (EDS). Tensile test and bend tests were carried out to evaluate the strength and ductility of the weld joint. The results showed that refined microstructure with narrow Heat Affected Zone (HAZ). Energy-Dispersive Spectroscopy analysis showed that reduced Microsegregation. The tensile results showed that 20 % improved strength compared to the base metal. Bend test didn’t result in any cracking.