Effect of Grain Size on Degree of Sensitization of Chrome-Manganese Stainless Steel

The use of chrome-manganese stainless steels (Cr-Mn SSs) of 200-series grade has tremendously increased in past few years in various applications like construction, home accessories, office appliances, light poles etc. Their mechanical properties, weldability and corrosion/oxidation resistance provide the best all-round performance stainless steels at relatively low cost. Therefore, they serve as an appropriate alternative to 300-series stainless steels now days. Similar to 300-series steels, Cr-Mn SSs are also submitted to various fabrication practices like welding, hot rolling, cold working, solution annealing or stress relieving processes. This leads to change in their grain size due to higher operating temperature during service. The grain size has a major influence on the intergranular corrosion (IGC) developed due to sensitization phenomena. Several investigations have been made on the influence of grain size on IGC behaviour of 300-series stainless steels, but this information about Cr-Mn SS is scanty till now. Therefore, in this paper an attempt has been made to evaluate the effect of grain growth on degree of sensitization (DOS) of Cr-Mn SS and finally concluded that the DOS decreases with increase in grain size.