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

• Published in: Journal of materials engineering and performance 2021-08, Vol.30 (8), p.6050-6067
• Main Authors: Arulmurugan, B., Balaji, D., Rajkumar, S., Kamaraj, M, Mageshwaran, V., Sathishkumar, M., Manikandan, M., Arivazhagan, N.
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Quality Control; Reliability; Safety and Risk; Tribology
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-021-05810-4

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.