Obtaining Single-Layer Superaustenitic Stainless Steel Weld Claddings by the GMAW Process with Rotating Electrode: Influence of the Shielding Gas

This work investigates the performance of single-layer superaustenitic stainless steel weld claddings deposited by the GMAW and GMAW-RE processes with Ar-2%O2 and Ar-25%He. The weld bead profile and microstructure were studied through optical and scanning electron microscopy and electron backscattering diffraction techniques. The mechanical properties were evaluated by tension, bending, and microhardness tests, and the corrosion performance was evaluated by potentiodynamic and potentiostatic tests to determine the pitting potential and the critical pitting temperature. The results revealed an austenitic microstructure containing a low fraction of the secondary phases for all conditions. The main difference was the presence of partially diluted zones in deposits obtained with Ar-2%O2 while no evidence was noted for Ar-25%He as a consequence of a shallow and flatter weld bead profile. Although thicknesses higher than 5mm and equivalent mechanical properties were obtained, the cladding deposited by the GMAW-RE process using Ar-25%He was unique showing the desired corrosion performance. These results indicate that single-layer claddings deposited by the GMAW-RE with Ar-25%He have the potential to be a cost-effective alternative to industrial application but supplementary research is still necessary to a definitive conclusion.