Effect of Warm Rolling on Micro-deformation Behavior and Mechanical Properties of Columnar-grained Fe-6. 5 mass%Si Alloy

Micro-deformation behavior and mechanical properties of columnar-grained Fe-6. 5 mass%Si alloy before and after warm rolling were investigated by means of micro-indentation and three-point bending tests. The results show that the columnar-grained Fe-6. 5 mass%Si alloy before warm rolling presents sink-in mode of micro-indentation, while pile-up mode with a number of arc-shaped deformation bands exists in the warm-rolled alloy. Compared with that of the alloy before warm rolling, the maximum bending fracture stress and maximum bending fracture deflection of the warm-rolled alloy are increased by 96% and 50%, respectively. The different micro-deformation behavior and mechanical properties of the columnar-grained Fe-6. 5 mass%Si alloy are ascribed to the changes of dislocation density, dislocation configuration and long-range order degree, which significantly improve the room temperature plasticity of the alloy after warm rolling.