Producing Nanostructured 304 Stainless Steel by Rolling at Cryogenic Temperature

Effect of rolling temperature on deformation-induced -martensite and reverted austenite was investigated. Rolling experiments were carried out at room temperature (without inter-pass cooling) and at liquid nitrogen temperature, respectively. The phase components, orientations, and microstructures are characterized by X-ray diffraction, electron backscattered scattering detection, and transmission electron microscopy. The (200) martensite was found to be of the preferred orientation in sample rolled at cryogenic temperature. An average grain size of about 300nm combined with high yield strength (approximate to 1500MPa) and good elongation (approximate to 35%) was obtained by the cryogenic temperature rolling and 240s annealing treatment.