International Research Journal of Education and Technology

This study investigates the corrosion behaviour of stainless steel 304 (SS304) weld joints produced using Cold Metal Transfer (CMT) twin welding, a low-heat input technique that minimizes thermal damage and preserves corrosion resistance. SS304, known for its durability and high resistance to corrosion, is widely used in industries such as food processing and petrochemicals; however, conventional welding methods like TIG and MIG can introduce high heat input, leading to carbide precipitation and intergranular corrosion, especially in chloride-rich environments. CMT twin welding offers controlled heat input, potentially addressing these issues. Welded SS304 samples were produced using CMT twin welding with varied parameters to optimize joint quality. Corrosion testing, Microstructural analysis using optical microscopy, mechanical testing revealed that the weld zone exhibited fine dendritic structures due to the controlled heat input, while the heat-affected zone (HAZ) showed minimal carbide precipitation and grain growth. The findings demonstrate that CMT twin welding enhances corrosion resistance in SS304 welds compared to conventional welding techniques. Results show lower corrosion current densities, higher impedance values, and improved resistance to pitting corrosion, attributed to the low heat input that preserves chromium-rich phases, essential for corrosion protection. This study concludes that CMT twin welding is a promising method for joining SS304 in applications where corrosion resistance is critical. Further research into optimizing CMT parameters and long-term corrosion testing in diverse environments is recommended to expand the applicability of CMT-welded SS304 in corrosive industries.

Key Words: CMT Twin process, Mechanical properties, Corrosion behaviour analysis , Microstructural analysis, Heat- affected zone (HAZ).