Research on Preparation, Oxidation Resistance and Corrosion Resistance of Cr/CrN Coating on SUS321 Stainless Steel Surface

Cr/CrN coatings were prepared on the surface of SUS321 stainless steel using magnetron sputtering technology.The microstructure and weight gain of samples after high-temperature oxidation and acidic salt spray corrosion experiments were characterized using scanning electron microscopy(SEM), X-ray diffraction(XRD) and analytical balance. The results show that the sample with a magnetron sputtering pressure ratio of P_Ar/P_N2=3∶1 exhibits the best antioxidation and corrosion resistance.Based on this, multi-layer Cr/CrN coa tings are prepared through cyclic deposition. The sample with 6-cycle coatings has a weight gain of 3.599 g/m² after oxidation at 600 ℃ for 200 h, with a dense surface oxide film and no peeling observed. In an acidic salt spray environment, the sample with a 6-cycle coating has no obvious oxidation for 480 h, and generates slight rust only at the edge after oxidation for 500 h. The 6-cycle Cr/CrN multilayer film coating prepared with a fixed magne tron sputtering pressure ratio of P_Ar/P_N2=3∶1 exhibits the best antioxidation and resistance to acidic salt spray corrosion.