Effect of MEVVA implanted Cr on the corrosion resistance of CrN coated on steel

摘要

Metal vapor vacuum arc (MEVVA) source implantation is a very attractive application for surface modification. Cathodic arc plasma deposition of CrN coating is applied in an industrial scale to improve the corrosion resistance of AISI 4140 steel. The effect of the Cr implanted by MEVVA (Cr/steel) on the corrosion behavior of CrN/steel through the surface modification was investigated. Both AISI 4140 steel and its coated assemblies (Cr/steel, CrN/steel, and CrN/Cr/steel) were evaluated in aerated 0.1N HCl solution. The crystal structure and compositional distribution for the MEVVA implanted Cr and cathodic arc deposited CrN on steel were studied by XRD and SIMS. The polarization resistance (R_p) for all samples was measured and compared using electrochemical impedance spectroscopy (EIS). The corrosion morphology of the samples was examined by SEM. The results indicated that the corrosion resistance of steel was significantly enhanced by MEVVA Cr ion implantation through the reduction of not only by defect on the CrN coating but also by increase the corrosion resistance by the CrN coating.