2024 年 64 巻 Extra-edition 号 p. ex107-ex111
Stainless steel is known to undergo pitting corrosion when it exposes to media solutions containing chloride ions. In this study, ZrTiAgN multilayer coatings were applied to the surface of 316L stainless steel using a cathodic arc deposition (CAD) process and the bias parameters were varied to explore the effect of different bias voltages (-60V, -120V, and -180V) on the coating microstructure and the corrosion behavior of the coated stainless steel. Two media containing chloride ions, NaCl and HCl solutions, were used for the corrosion tests. In addition, EPMA, XRD, and SEM were used to analyze the chemical composition, microstructure, and morphology of the coatings.
The experimental findings indicated that as the bias value increases, the silver (Ag) content decreases. The coatings consisted of a multilayer structure composed of ZrN and TiN phases, with only minimal amounts of amorphous Ag (0.04-0.1 at.%) doped into the film structure. All three different bias coatings exhibited well adhesion (HF1-HF2). In the corrosion test, the polarization test conducted with a NaCl solution revealed that the ZrTiAgN coating enhanced the corrosion resistance of 316L stainless steel. The specimens treated with a bias of -180V displayed the highest polarization resistance value, indicating the best corrosion resistance. Similarly, the ZrTiAgN coating significantly improved the corrosion resistance of 316L stainless steel in the HCl solution immersion test, with the best results observed in the bias -180V specimen. This outcome aligns with the findings from the polarization test.
