The Effect of Alloying Cu on Pitting Corrosion Resistance of Copper-bearing Ferritic Stainless Steel

摘要

Copper is a well-known alloying element which is used to improve the resistance to general corrosion of stainless steels. Our previous experiments show that the increase of copper content can acquire the excellent antibacterial properties and can also increase the tendency to cold formability of the ferritic stainless steels. However, the effect of alloying Cu on the resistance to localized corrosion has not been clarified sufficiently. In order to understand the effect of copper on pitting corrosion resistance of the ferritic antibacterial stainless steel, the electrochemical experiments were carried out and the anodic polarization curves were performed in 3.5% NaCl solution for two kinds of steels. The results reveal that the ε-Cu phase in ferrite matrix diminishes pitting corrosion resistance of the antibacterial stainless steel in the chlorides medium. It is connected with the poor passive behavior of the ε-Cu phase inclusions.