Evaluation of corrosion performance of two Mn-containing stainless steel alloys

300 series austenitic stainless steels (SSs) are widely used as structural materials in various corrosive environments because of their excellent corrosion resistance and good mechanical properties. However, due to the rapid increase in Ni cost over the last few years, there have been attempts to develop cheap SSs while still maintaining their relatively high corrosion resistance. The possible replacements for Ni (a gamma stabilizer) in SSs are Mn, N and Cu etc. In this paper, the effect of Mn addition on the corrosion properties of two SS alloys, i. e. 202M2 and 202M4, is discussed and results are compared with those of 304 SS alloy. Results of different tests showed that overall corrosion resistance properties (measured in terms of pitting potential (E_pit), metastable pitting events density and time to failure etc.) decreased with an increase in Mn content of the alloys.