Mechanical Properties of Duplex Fe—Ni—C Alloys Prepared by Powder Metallurgy Techniques

Abstract

Duplex Fe–20 vol.-%Ni–C alloys having nominal carbon contents ranging from 0·04 to 0·21 wt-% were prepared by powder metallurgical techniques. The resulting compacts were then hot and cold rolled to 0·5 mm thick sheets which, when quenched into iced water after high-temperature annealing, developed a type of fibre-reinforced structure in which a high-strength martensitic phase and a ductile ferritic phase were both elongated and aligned in the direction of rolling. Increasing the carbon content improved both tensile strength and, rather suprisingly, ductility. The duplex alloys produced by powder metallurgy were stronger and more ductile than those obtained by vacuum melting and casting.