Influence of processing temperature on the microstructures and tensile properties of 304L stainless steel by ECAP

304L austenitic stainless steel was successfully processed by equal channel angular pressing (ECAP) in the temperature range of 500–900 °C, and the influences of processing temperature on the microstructures and tensile properties were investigated. At temperature below 700 °C, the microstructures were characterized by lamellar structures and many bundles of deformation twins, which led to a high tensile strength but low elongation-to-failure. With increasing the processing temperature up to 800 °C, dynamic and also static recovery took place and more equiaxed subgrains with low dislocation density were obtained. Deformation twins were found to form only in some grains in the form of individual bands. A low strength and a high elongation-to-failure were achieved compared with those processed at low temperature. The best combination of both high strength and large elongation took place at the processing temperature of 800 °C.