Investigation of ER308L and ER309L filler wires on dissimilar metals between carbon steel and 3CR12 ferritic stainless steel by GTAW through boiler fabrication in a sugar factory

Dissimilar metal welding is a popular process in very large coal and gold, power generation, and pulp and paper factories. It has mainly been applied to produce large boilers in sugar factories. The aim of the present study was to examine the characteristics of dissimilar metal welded joints made from carbon steel and 3CR12 ferritic stainless steel. The welding specimen was made from filler wires of ER308L and ER309L, and a gas tungsten arc welding process was employed for the V-shaped butt weld joints. The effects of the process parameters, such as the microstructural characteristics and mechanical properties, were investigated. The results from the welding parameters with filler wire of ER308L applied at 70A of welding current showed the microstructure of delta ferrite and austenite. In comparison, 100A of welding current presents delta ferrite, austenite, and martensite. Furthermore, carbide formation was not observed in the fusion zones of any of the experiments. When the ER308L filler wire was used, the amount of delta ferrite was higher than that of the ER309L filler wire, and the amount of delta ferrite increased with increasing hardness. In addition, the results of the filler wire of ER308L could replace the ER309L filler wire, which effectively reduces the material cost.