Impact toughness transition temperature of ferritic Fe-Al-V alloy with strengthening Fe2AlV precipitates

The Fe2AlV-strengthened ferritic alloys show an appreciable flow stress and creep strength up to 700 °C, comparable to those of other iron aluminide based alloys with coherent microstructures. In the present study, the brittle-to-ductile transition temperature (BDTT) of the Fe76Al12V12 alloy was investigated in the peak hardness condition by Charpy test. A BDTT value of 617 °C was estimated using the criterion of the midpoint of the impact-energy transition region. An attempt is made to gain understanding of the micro-mechanisms controlling the fracture process and their interaction with the microstructure in order to identify ways for enhancing ductility in disordered Fe-Al alloys strengthened by coherent precipitates.