Effect of cold rolling on microstructure and properties of low-nickle austenitic stainless steel

Cold rolling at a reduction ratio of 9.2%~68.4% was carried out for a metastable low-nickle austenitic stainless steel, and the mechanical properties and microstructure evolution of the steel were studied. The results show that the martensite content increases with the increasing of deformation and a good agreement was found between the experiment results and the Angel model. The α'-martensite and Ε-martensite exist at the same time and nucleate at the shear-band intersections with the increasing of the reduction ratio up to 17.1%, however, the Ε-martensite disappears while the α'-martensite constantly grows up when the reduction ratio continues to increase. The tensile strength, yield strength, hardness and the yield strength and tensile strength ratio increase with the increasing of the reduction ratio up to 68.4%, while elongation decreases sharply. At the same time, the ratio of tensile strength to Vickers hardness is constant and approximately equal to three in all percentages of cold rolling. ©, 2014, Editorial Office of Transactions of Materials and Heat Treatment. All right reserved.