Deformation microstructures and tensile properties of an austenitic stainless steel subjected to multiple warm rolling

Abstract

The deformation microstructures of a 316L-type austenitic stainless steel subjected to multiple bar rolling to a total strain of 2 at temperatures of 773–1173K and their effect on the mechanical properties at ambient and elevated temperatures were studied. The multiple warm rolling was accompanied by significant grain refinement. The finally evolved transverse grain size decreased from 3.4µm to 0.85µm with a decrease in the rolling temperature from 1173K to 773K. The warm rolled steel samples were characterized by significantly increased strength properties. The strengthening was studied by tensile tests at ambient and elevated temperatures. A decrease in the rolling temperature from 1173K to 773K increased the yield strength from 720MPa to 945MPa or from 395MPa to 470MPa at room temperature and 973K, respectively. The strengthening obeyed Hall-Petch relationship with a grain size strengthening coefficient decreased from 410MPaμm0.5 at room temperature to 140MPaμm0.5 at 973K.