A New Method of Studying the Corrosion Behavior of Selected Heat Affected Zones on UNS S31600 Stainless Steel Welded Joints

Abstract Austenitic stainless steels are widely used in industries such as desalination because of their appropriate mechanical properties, good corrosion resistance and weldability. However the welding process of austenitic stainless steels may adversely affect their corrosion resistant characteristics due to modifications of local composition and microstructures. Standard cyclic polarization method (ASTM(1) G611) is commonly used to evaluate the relative localized corrosion susceptibility of stainless steels by determining the breakdown potential; however in principle this method cannot be used to welded joints where different heat affected zones exist. Techniques such as local electrochemical cells have been developed to perform local potential or polarization measurements; however these local cell techniques often experience difficulties in the control of the standard testing conditions. In this work a new method of carrying out electrochemical measurement on selected welding zones is employed. Standard cyclic polarization tests were applied to the selected zones on a welded UNS S31600 (316) stainless steel joint exposed to sodium chloride solution.