Abstract

As-cast microstructures of {M - 30Cr - 0 to 5% C} ternary alloys. Part III: Iron-base alloys

Author(s): Patrice Berthod, Ahmed Dia, Moussa Ba

As seen before with nickel alloys and cobalt alloys in the two first parts of this work, it was found again here that high carbides fractions can be also achieved in iron-based alloys if they contain sufficient quantities of carbon. With the simple ternary Fe-30Cr based alloys studied here, as predicted by thermodynamic calculations, awide range of fractions of chromiumcarbides was really observed since more than 50% of carbides, in mass or volume fraction, were observed in the 5wt.%C-containing alloy, whichwas still free of any precipitated graphite. If carbideswere only in the interdendritic eutectic form for the low carbon alloys, additional pro-eutectic carbides are present in alloys containingmore than 3wt.%C.Very high values of hardness can be then also expectedwith such carbon-rich iron(+chromium) alloys, as for the cobalt-based alloys, by comparison with the nickel-based ones in which graphite was present for carbon contents higher than 3.5wt.%.