Equiaxed and oriented microstructure in high chromium cast iron

Abstract

It has been proved that an addition of boron carbide and shredded steel scrap introduced as an inoculants to the chromium white cast iron changes the microstructure of castings. The operation increases the number of crystallization nuclei of M7C3 carbides. In this case the B4C carbides act as substrates for the nucleation of M 7C3 (chromium carbides). Castings after B4C inoculation have fine grain fracture surface. Primary precipitates of chromium carbide also appeared, lowering the mechanical properties of as-cast parts. Additionally, in order to increase the mechanical properties of chromium cast iron, unidirectional solidification was used. In this case, 0.3 wt. % cerium was used as inoculant.