Substructure Formation, Texture, and Mechanical Behavior of Warm Rolled 2205-Type Duplex Stainless Steel

Abstract

The microstructural evolution and mechanical behavior of 2205 duplex stainless steel were studied after plate warm rolling at 600 °C with 60 and 80% thickness reduction, using different microscopy techniques, X-ray diffraction, and tensile and hardness testing. The microstructures of the warm-rolled specimens consisted of flattened wavy grains. The texture evolution during rolling in the ferrite domain presented α-fiber and rotated cube components, while the austenite showed brass, copper, and cube components to a lesser extent. Intense formation of entanglement and dislocation forests characterized the microstructure. In ferrite, there was an intense formation of dislocation substructures and cell blocks. In austenite, the substructure was characterized by planar gliding and the formation of dislocation entanglements. After warm rolling, the tensile strength reached 1185 and 1328 MPa at 60 and 80% thickness reduction, respectively. Compared with the as-received steel, the warm work raised the mechanical strength level by between 65 and 72%. These results highlight the prospects for innovative routes to the industrial production of this class of duplex stainless steel, such as cold rolling suppression, considering even ductility reduction.