Hastelloy C276/AISI SS304 Dissimilar Metal Welding: A Comparative Review of the Effective Application of Laser and Micro-GTAW

Hastelloy C276, known for its high temperature strength and corrosion resistance, is essential in the manufacture of medical devices and aerospace components. This study developed a micro-controlled GTA welding technology capable of precisely welding 0.4 mm thick dissimilar metals, Hastelloy C276 and SS304. This technology utilizes advanced digital signal processing (DSP) to control the arc time with precision up to 1/100 of a second and improves the welding quality through spot stitch and cold-welding functions. Moreover, the use of 300A inverter-type GTA welding equipment and 2 kW fiber laser welding equipment in this study improved the precision of the welding process. The effectiveness of this technology has been validated through macro-inspections and heat-affected zone (HAZ) analysis. The new welding technique demonstrates the potential to overcome existing welding limitations on thin Hastelloy C276 plates by integrating digital signal processing and rapid response control mechanisms.