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 duc tility of Fe3Al-based alloys has been systematically investigated by studyi ng the order structure, the microstructure, the surface state and the textu re evolution during rolling and annealing. A comparison bt tween a single c rystal Fe3Al-alloy and the polycrystalline Fe3Al alloy is presented in orde r to discuss the effect of the pancake shaped grains and the transverse gra in boundaries on the room temperature ductility. The experimental results d emonstrate that the order structure, microstructure and texture are mainly responsible for the improved intrinsic ductility, while an appropriate surf ace state can suppress the extrinsic environmental embrittlement by delayin g the formation of microcracks. The pancake shaped grains hardly influence the hydrogen embrittlement, but could be responsible for the improved ducti lity at room temperature by increasing the resistance to crack propagation. (C) 2001 Elsevier Science Ltd. AH rights reserved.