Effect of Cold Deformation on Phase Evolution and Mechanical Properties in an Austenitic Stainless Steel for Structural and Safety Applications

The effects of cold deformation on the formation of strain induced ά martensite and mechanical properties of an austenitic stainless steel have been examined. X-ray diffraction analysis has revealed that 30% and 40% cold rolling have resulted in the formation of 24% and 31.5% martensite respectively. Microstructural investigation has demonstrated that the formation of martensite is enhanced with increase in the percent deformation at 0 °C. Investigation of mechanical properties reveals that hardness, yield strength and tensile strength values increase where as percent elongation drops with increasing deformation. The fractographic observation corroborates the tensile results. Examination of sub-surface at the fractured end of the tensile sample manifests that void/microcrack nucleation occurs in the interfacial regions of the martensite phase as well as at the austenite-martensite interface.