Welded Stainless Steel: Surface Oxidation, Characterization, Hardness and Corrosion Resistance

Abstract

This research presented the surface oxidation of stainless steel grade 304 (S304) welded by a gas tungsten arc welding (GTAW) process. The welded S304 was inspected by visual and penetrant testing methods. The surface of the welded specimen was oxidized by the chromic solution to an obtained oxide film on S304 welded specimen. After that, the structural phase and crystallite size of the oxide film were investigated by X-ray diffractometer (XRD). The thickness of the obtained film was analyzed by an atomic force microscope (AFM). Furthermore, the effects of the oxide film on hardness and corrosion properties of specimen were analyzed by Vickers hardness tester and potentiostat instrument to study the correlation between the property of oxide film and the surface properties of the welded pipe S304 after oxidation.