Role of Thermomechanical Treatment on the Sensitization Evolution of High-Mn Austenitic Stainless Steel

Impact of strain-induced martensitic reversion and grain refining on sensitization behavior of high Mn steel was analyzed. The electron backscatter diffraction, optical microscope, and scanning electron microscopy have been used to demonstrate the microstructural examination. The degree of sensitization was examined using double-loop electrochemical potentiokinetic reactivation test. The findings shown that during deformation, fine recoverable grains of strain-induced martensitic and austenite combined formed on the surface of high Mn steel. The degree of sensitization of the cold work samples is significantly higher than that of the as-received sample due to the production of strain-induced martensite. Furthermore, a 15% CW sensitization is higher than a 30% or 50% CW sensitization. Conversely, the reversion of strain-induced martensite and fine reverted austenite grains abolished the sensitization of the high Mn steel sample that had been subjected to cold work after it had been thermally aged for 6 hours at 900 °C.