The effect of Mn and Al contents on the solvus of kappa phase in austenitic Fe-Mn-Al-C alloys

It is known that the precipitation of the kappa phase has significant effec t on the mechanical properties of Fe-Mn-Al-C alloys. The kappa phase may be present along the grain boundaries tinter-granular) or within the grains ( intra-granular). The effect of Al and Mn contents on the solvus of both int er- and intra-granular kappa phase was investigated for a composition range of Fe-(21-32 wt.%)Mn-(2-10 wt.%)Al-1C. The results clearly indicate that t he addition of Al raises the solvus of both inter- and intra-granular kappa phases significantly, while the addition of Mn only causes slight reductio n of the solvus. The implication of this result on the development of this alloy is also discussed. (C) 1999 Elsevier Science S.A. All rights reserved .