Structural strengthening of an austenitic stainless steel subjected to warm-to-hot working

The effect of multiple rolling in the temperature interval of 500-1000 °C on the microstructure and the tensile behaviour of an austenitic stainless steel was studied. The structural changes during warm-to-hot working were characterized by the elongation of original grains towards the rolling axis and the development of new fine grains. The fraction of fine grains and the average grain size increased with increasing the rolling temperature. The multiple hot rolling resulted in significant strengthening. The offset yield strength approached 1030 MPa in the specimen processed at 500 °C, while a strength of 480 MPa was obtained after rolling at 1000 °C. The relationship between the deformation microstructures and the tensile behaviour is discussed.