This study examines the joining of a 4 mm thick plate of alloy C-2000 by continuous current gas tungsten arc welding (CCGTAW) and pulsed current gas tungsten arc welding (PCGTAW) techniques by using ERNiCrMo-4 (filler-4) and ERNiCrMo-17 (filler-17) as filler wires. This article aims to present a comprehensive structure-property relationship of these welded joints. Weld microstructure was characterized with optical microscope and scanning electron microscope. The results show that PCGTA weldments possess a refined microstructure compared to the CCGTA weldments in both filler wires. Energy-dispersive x-ray spectroscopy study divulged the existence of chromium (Cr)-rich and slight molybdenum (Mo)-rich segregation in the fusion zone interdendritic region of all the four weldments. However, the extent of microsegregation is very low in PCGTA-filler-4 weldment when compared with the other weld joints. Significant grain refinement (8.9 to 9.77%) was observed when shifting the welding mode from CCGTAW to PCGTAW. Weldment produced with PCGTAW-filler-4 offers higher tensile strength (~4 to 6%), higher toughness (~5 to 7.5%), and higher hardness (~3 to 6%) compared to other weldments.

Influence of Filler Wire and Welding Process to Mitigate the Microsegregation of Alloy C-2000 Using Continuous and Pulsed Current Gas Tungsten Arc Welding Techniques

Hastelloy C-2000 and C-276 are widely used in Flue Gas Desulphurization (FGD) system and Chemical Processing Industries (CPI). Current work is focused on weld microstructure, and mechanical propert...

Kiran Jacob Johny

Papers

Investigation on Microstructure and Mechanical Properties of Corrosion Resistance Alloy C-2000 Fabricated by Conventional Arc Welding Technique