The significant impact of cold deformation on structure-property relationship in phase reversion-induced stainless steels

The present study aims to investigate the impact of cold deformation on structure-property relationship in phase reversion-induced stainless steels. The commercial 18Cr-8Ni stainless steel was cold rolled at room temperature to 30%, 60% and 90% thickness reduction, respectively and subsequently annealed at 900 °C for 1-100 min. Evolution of phases in selected samples was identified and quantified by X-ray diffraction together with the corresponding microstructural characterization through optical, scanning and transmission electron microscopy, and electron backscatter diffraction. Mechanical properties of selected samples were determined by the tensile test. The results indicated that parts of metastable austenite transformed into strain-induced martensite during cold rolling process, and the volume fraction of martensite increased with increase in cold rolling reduction. The kinetics of reversion transformation from martensite to austenite was fastest in 90% cold-rolled sample during annealing treatment. The austenite grain size for the 90% cold-rolled sample after annealing was smallest and most uniform, which induced highest yield strength and elongation combination.