Investigation of the effects of current in similar welds and different filler metals in dissimilar welds of S235JR and SAF2205 steels on microstructure and mechanical behavior using the gas tungsten arc welding method

Duplex stainless steel shares the structural properties of both austenitic and ferritic stainless steels. It has better corrosion resistance and mechanical properties than other stainless steels. Furthermore, thanks to these properties, it is an increasingly popular material. However, due to this, the material procurement cost is higher than other stainless steel types. Although this product is more difficult to weld and process, it is still highly preferred for shafts and spindles due to its other properties. Welding is a manufacturing method for such equipment. In some applications, welding is required to join duplex stainless steels and structural steels. This combines the economic advantages of structural steels with the superior mechanical strength and chemical resistance of duplex steels, optimizing performance and balancing cost-effectiveness. In this thesis, EN 1.0037-EN 1.0037 ferritic-pearlitic structural steel and EN 1.4462-EN 1.4462 duplex stainless steel sheets (thickness: 3 mm) were joined using gas tungsten arc welding using three different heat inputs and three types of filler wires. The effects of heat transfer on the microstructure and mechanical properties of the sheets were investigated in the same sheets and the different types of filler wire used in the welding process. The internal structures of the welded joints were investigated using a microscope, and their mechanical features were discovered by hardness measurement and bending and tensile tests. While better results were explained in EN 1.0037 – EN 1.0037 and EN 1.0037 – EN1.4462 weld joints, it was observed that the welding performance and internal structure were negatively affected as a result of low heat input in the weld joints of EN 1.4462 – EN 1.4462 plates.