Corrosion resistance of stainless steel layer prepared by twin-wire indirect arc surfacing welding

Twin-wire indirect arc welding(TWIAW) has advantages of high deposition efficiency and low dilution rate. Compared to traditional MIG welding, the molten pool solidifies more rapidly, influencing final microstructure and associated corrosion resistance property. The intergranular corrosion resistance and the pitting corrosion resistance of stainless steel surfacing layer prepared by TWIAW were investigated through electrochemical testing. The semiconductor characteristics of formed passive film were analyzed by Mott-Schottky curves. The stainless steel surfacing layer prepared by TWIAW achieved higher resistance to intergranular corrosion and pitting corrosion, compared to that of MIG surfacing layer. In addition, the carrier concentration in passivation film of TWIAW surfacing layer was also significantly lower than that of the MIG layer. The larger cooling rate of TWIAW layer improved homogeneous solidification microstructure, which led to better corrosion resistance properties.