On the effect of the B2 thermomechanical treatment in improving the room temperature ductility of Fe₃Al-based alloys

The effect of the B2 thermomechanical treatment on the room temperature ductility of Fe₃Al-based alloys has been systematically investigated by studying the order structure, the microstructure, the surface state and the texture evolution during rolling and annealing. A comparison between a single crystal Fe₃Al-alloy and the polycrystalline Fe₃Al alloy is presented in order to discuss the effect of the pancake shaped grains and the transverse grain boundaries on the room temperature ductility. The experimental results demonstrate that the order structure, microstructure and texture are mainly responsible for the improved intrinsic ductility, while an appropriate surface state can suppress the extrinsic environmental embrittlement by delaying the formation of microcracks. The pancake shaped grains hardly influence the hydrogen embrittlement, but could be responsible for the improved ductility at room temperature by increasing the resistance to crack propagation.