Effect of Temperature on the Electrochemical Corrosion Behaviour of Super Austenitic Stainless Steel 254SMO Joints for Double-sided Synchronous TIP TIG Arc Butt Welding
Double-sided synchronous TIP TIG arc butt welding(DSTTABW)is a welding technology that can effectively re-duce the heat input during welding.In this paper,4 mm thick 254SMO super austenitic stainless steel plate was welded us-ing DSTTABW and the effect of temperature on the pitting behaviour was investigated by using electrochemical worksta-tion,including potentiodynamic polarization,cyclic potentiodynamic polarization,Mott-Schottky(M-S)and EIS tests.The results show that the base metal area,transition area and welded area have pit corrosion,of which the transition area is the most serious.The corrosion resistance of the 254SMO joints decreases with the increasing temperature,and the critical pit-ting temperature locates at the temperature between 40℃and 45℃.The pitting resistance of the joint is equivalent to that of base material,and both meet the engineering standard.The joints and the base material passive as the same mechanism,and the passivation film show n-p type semiconductor characteristics.But the film stability on the surface of 254SMO joints is slightly lower than that of the base material when the temperature is greater than 45℃.
double-sided synchronous TIP TIG arc butt welded254SMO super austenitic stainless steeltemperaturepit-tingpassivation film
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