Corrosion Properties of Al-Modified Austenitic Stainless Steel Prepared by Laser Cladding

The layer of Al-modified austenitic stainless steel was formed by laser cladding with pre-placed FeNiCrAl powder on 304SS surface. No porosity and free of cracks was observed at power density of 31.25 w·s·mm-2. The microstructure of cladded layer was observed by OM (optical microscope) and SEM (scanning electron microscope). Compared with 304 (the substrate), laser cladding FeNiCrAl layer exhibit excellent pitting resistance in mixed acid solution. Anodic polarization curve indicated that the corrosion potential of laser cladding layer was 70 mV higher than that of 304SS (-345.7 mV), while self-corrosion current density of 304SS was 2.4 times as high as that of laser cladding layer.