Effect of Tensile Pre-strain on Mechanical Properties of Austenitic 301 Stainless Steel

The effect of tensile pre-strain on the microstructure and mechanical properties of austenitic 301 stainless steel was investigated by combining experiments and simulations. The specimens with 0, 3, 6, and 12% pre-strain were prepared and stretched at room temperature. The research findings demonstrated that the tensile pre-strain served as an effective method to significantly improve the tensile strength, yield strength, and surface microhardness of austenitic 301 stainless steel. In particular, when the specimen was subjected to 12% pre-strain, the tensile strength, yield strength, and surface microhardness increased by 4.4, 48.6, and 23.7%, respectively, compared with the as-received specimen. However, with the increase of the pre-strain level, the toughness and plasticity were weakened. By scanning electron microscope, it was observed that 12% pre-strain specimen showed the fracture feature of quasi-cleavage to some extent, while the fracture morphologies of the remaining specimens were characterized by significant ductile fracture. The internal mechanism of tensile pre-strain treatment to improve the strength and microhardness of austenitic 301 stainless steel was revealed by XRD and metallography. Martensite transformation occurred in the process of pre-strain. As the tensile pre-strain level rose, the volume fraction of martensite increased, which strengthened the mechanical properties of austenitic 301 stainless steel.