Effect of FeTi-FeB inoculation on the shape of carbide reinforcements in hypoeutectic high chromium white cast iron

Abstract

FeTi-FeB was added to molten high chromium white cast iron in amounts of 0.5-2.5 wt% at 50 degrees C above the melting temperature. The samples were produced in four groups. The first group samples were investigated as cast, the second group homogenized at 1000 degrees C for 1 h, and the other two groups were also homogenized at 1000 degrees C but for 3 and 6 h, respectively. To study the effect of FeB and FeTi on the microstructure, the samples were characterized by optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction and hardness tests. Wear tests were performed using a pin-on disc. A homogeneously dispersed carbide microstructure was produced by the homogenization heat treatment method. The addition of FeTi-FeB inoculants to high Cr white cast iron played an important role in the distribution of hard carbides. The chemical rate and the carbide volume varied on account of the added hard inoculant particles. TiB2, Cr3C2, M7C3, M23C6, and gamma-FeCr phases formed on the surfaces. The hardness and wear resistance were improved considerably due to FeTi-B inoculation.