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

The deformation microstructures of a 316L-type austenitic stainless steel subjected to multiple bar rolling to a total strain of 2 at temperatures of 773-1173 K 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 3.4 µm to 0.85 µm with a decrease in the rolling temperature from 1173 K to 773 K. 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 1173 K to 773 K increased the yield strength from 720 MPa to 945 MPa or from 395 MPa to 470 MPa at room temperature and 973 K, respectively. The strengthening obeyed Hall-Petch relationship with a grain size strengthening coefficient decreased from 410 MPa μm0.5 at room temperature to 140 MPa μm0.5 at 973 K.