Abstract

Experimental and thermodynamic study of iron (30wt.%cr) - base alloys containing between 2.5 and 5.0wt.% of carbon

Author(s): P.Berthod, M.Ba, A.Dia, L.Aranda

Six {Fe-30wt.%Cr}-based alloys containing from 2.5 to 5.0 wt.%C, were cast and heat treated during 50h for microstructure stabilization at 1000, 1100 and 1200°C. The melting ranges and the carbides’ characteristics were experimentally characterized, and compared to the results of thermodynamic calculations. The microstructures are hypo-eutectic (2.5wt.%C), eutectic (3%C) and hyper-eutectic (3.5 to 5wt.%C), and the carbides are Cr7C3. The carbides fraction increases with the carbon content and tends to decrease with temperature. The carbon-richest alloys are hardened by more than 50vol.% of carbides. The results of thermodynamic calculations are consistent with the observed microstructures, but less with the fusion’s temperature range. The obtained hardness, which can be higher than 800Hv, is favorable to a good wear behavior. Unfortunately it tends to decrease after exposure at 1200°C.