Abstract: The optimal heat-treatment parameters for the high-chromium cast iron blades of shot blasting machine were researched on the basis of the orthogonal experimental design. With the addition of trace elements, vanadium and nano-sized WC/TiC particles, the wear resistance of high-chromium (Cr) cast-iron casting was improved, thus extending its service life. The results indicated that the blades′ hardness was 60 HRC and its best wear resistance was obtained at a quenching soaking time of 3 h while temping at 450 ℃ for 2 h. By adding the trace elements, vanadium and nano-sized WC/TiC particles, the microstructure of the blade was refined, the carbide morphology was changed, and the wear resistence improved by 30%. Results showed that the wear resistance of high-Cr blades can be increased by optimizing the heat-treatment process and the blades′ composition, thereby proving the comprehensive benefit of this study in industrial applications.

Key words: high-chromium cast iron, heat treatment, hardness, wear resistance, Cr