Mechanically Induced Martensitic Transformation of Hot Rolled and Annealed 304L Austenitic Stainless Steel at Room and Cryogenic Temperatures

The 304L austenitic stainless steel is susceptible to mechanically induced martensitic transformation from slightly above room temperature down to cryogenic temperatures. In this work, austenitic 304L steel produced by two different thermomechanical processes, hot rolling (HR) and cold rolling and annealing (CR/A), were subjected to martensitic transformation by rolling and by tensile tests at 298 K and 155 K and the volume fraction of martensite was determined by X-ray diffraction and ferritescope measurements. The results showed that the martensitic transformation was complete for CR/A samples rolled at 155 K and that the volume fraction of martensite was larger in CR/A samples than in HR samples in all cases.