Structure and properties of Fe–(3–7 wt.%)Al–0.5 wt.%C alloys

Effect of aluminium (3, 5 and 7 wt.%) on the microstructure and mechanical properties of Fe–0.5 wt.%C alloys has been investigated. These alloys were prepared by air induction melting with flux cover (AIMFC). The AIMFC ingots were hot-forged and hot-rolled at 1373 K. Hot-rolled alloys were characterised using optical microscopy, X-ray diffractormeter (XRD) and scanning electron micrograph. The ternary Fe–Al–0.5C alloy containing 3, 5 and 7 wt.% Al exhibited two-phase microstructure: α Fe–Al (matrix) with disordered BCC structure and Fe3AlC0.5 precipitates with perovskite structure. An increase in aluminium content from 3 to 7 wt.% in Fe–Al–0.5C alloys has no significant influence on creep properties at 873 K, however resulted in significant improvement in room and high temperature strength (at 873 K) accompanied by a reduction in room temperature ductility.