Mechanical and metallurgical properties of GTAW dissimilar welds between SUS304 and SA213T11 using ER308 filler metal, preliminary study

Dissimilar welding between austenitic stainless steel SUS304 and low alloy ferritic steel SA213T11 is widely used in the petrochemical and power generation industries because this combination is suitable for use in corrosive and high-temperature environments. This study presents a preliminary investigation of dissimilar metal welding between austenitic stainless steel SUS304 and low-alloy steel SA213T11 using Gas Tungsten Arc Welding (GTAW) with ER308 filler metal. The mechanical and metallurgical properties of the welded joints were evaluated through hardness testing, tensile testing, bend testing, and microstructural analysis. The results show that the welds produced are of acceptable quality, with sound bead appearance and no visible surface defects. Hardness values vary across different weld regions, with the weld zone exhibiting higher hardness due to the presence of δ-ferrite. Tensile tests indicate that the weld strength is comparable to or greater than the weaker base metal, and failure occurs outside the weld region. Microstructural observations reveal significant changes in the heat-affected zones and weld metal, influenced by the thermal cycle and filler composition. These findings provide insight into the performance of ER308 in joining dissimilar metals, which is relevant for applications in power and petrochemical industries.