Multi-component white cast iron (MWCI) possesses superior anti-erosion performance compared to high-chromium cast iron (HCCI). However, MWCI is not economically viable due to the high cost of transition metals. To address this issue, two types of high-chromium multi-component cast alloys (Hi-Cr MCAs) have been developed by substituting expensive transition metals with cost-effective Cr. Therefore, this study investigated erosion performance of Hi-Cr MCAs at 1173 K by reducing the contents of V, Mo, W, and Co from 5 mass% to 3 mass% and increasing the Cr content from 5 mass% to 18 mass% and 27 mass%. A comparison is made with two typical heat-treated MWCI materials (5V-5Co and 5Nb-5Co). The evaluations carried out included investigations of microstructure (matrix and carbides), hardness, heat oxidation, and wear mechanism conditions. Prior to testing, the material was heat treated to increase the hardness of the matrix and form secondary carbides. The microstructure and high temperature corrosion behavior of the material were evaluated using optical microscopy, SEM-EDS and XRD. The hardness of the material was measured using a high-temperature Vickers hardness tester. Meanwhile, a high-temperature erosion testing machine was used to understand the erosion wear characteristics of the material at 1173 K with three different impact angles (30°, 60°, and 90°). The results show the presence of M7C3, M2C, and MC carbides precipitated in the microstructure of MWCI. In contrast, MC carbides were not observed in either Hi-Cr MCA, possibly due to the reduction of V, Mo, W, and Co from 5 mass% to 3 mass%. Both Hi-Cr MCAs exhibited higher carbide volume fraction (CVF) and hardness than MWCI, attributable to the increased Cr content, which in turn enhanced their high-temperature erosion wear resistance. Moreover, the superior high-temperature oxidation resistance of 27Cr-MCA contributed to its highest overall wear resistance among all specimens.
Kusumoto et al. (Fri,) studied this question.