Effect of thermo-mechanical processing and heat treatment on structure andmechanical properties of an electroslag remelted Fe-8.5wt%Al-1.1wt%C alloy

Electroslag remelted (ESR) ingots of Fe-8.5wt%Al-1.1wt%C alloy were hot for ged at 1373 K to 83% reduction. The forged ingots were hot rolled at 1373 K to 53% rolling reduction and heat treated at 1173 K for one h. The thermo- mechanical processing and heat treatment of the ESR alloy ingots resulted i n breakdown of cast dendritic structure leading to a homogeneous microstruc ture with fine Fe3AlC0.5 precipitates. This was accompanied by a significan t improvement in ductility and strength of the alloy. It is shown that the addition of carbon to Fe-8.5wt%Al binary alloy does not result in a signifi cant loss in ductility. The presence of Fe3AlC0.5 precipitates results in a n increase in strength and improvement in creep and stress rupture properti es. The cast and wrought alloys exhibited similar creep and stress rupture properties. The reasons for this are discussed. An attractive combination o f strength, ductility and creep and stress rupture properties not yet repor ted for Fe-Al alloys was achieved by thermomechanical processing and heat t reatment. (C) 1999 Elsevier Science S.A. All rights reserved.