EFFECT OF PROCESSING ON MECHANICAL-PROPERTIES OF AN FE-8.5 WT-PERCENTAL-1.1 WT-PERCENT C-ALLOY

A Fe-8.5 wt.% Al-1.1 wt.% C alloy was melted under a flux cover by air induction melting (AIM). Subsequent processing of the AIM ingots thro ugh electroslag remelting (ESR) resulted in a significant improvement in ductility. This may be attributed to the refined axially oriented g rain structure, free from internal defects observed in the ESR ingots. The alloy exhibited a significantly higher yield strength at test tem peratures up to 500 degrees C than those reported for complex Fe-AL al loys with comparable aluminium contents. This may be due to dispersion strengthening caused by the presence of a large volume fraction of Fe 3AlC0.5 precipitates in the alloy. Though the addition of carbon may d ecrease ductility, it allows commercial production of alloys with reas onable (8%) room temperature ductility, melted using cheap raw materia ls and a low cost melting procedure. The high carbon ESR alloy offers the best ductility reported for cast Fe-Al alloys with similar alumini um contents. (C) 1998 Elsevier Science S.A. All rights reserved.