Effects of cerium on the inclusions and microstructure of wear-resistant steels and their correlation with mechanical properties

The regulation of inclusions and microstructure is an important factor influencing the mechanical properties of low alloy wear-resistant steels. This paper investigated the effects of the rare earth (RE) element Ce on the modification of inclusions and microstructure in wear-resistant steel, and their relationship with mechanical properties. The results indicate that the addition of Ce markedly diminishes the prevalence of inclusions in steel, facilitating the formation of near-spherical RE inclusions which reinforce the interfacial bonding between the inclusions and the steel matrix. Simultaneously, the addition of Ce forms a more compact and wear-resistant steel structure and inhibits the bainite transformation. The incidence of small-angle grain boundaries in the steel is significantly reduced from 25.3% to 11.0%, and the average kernel misorientation decreases from 1.13° to 0.78°. Considering the aforementioned microstructural alterations and inclusion characteristics, the low-temperature impact toughness of the wear-resistant steel has been augmented, exhibiting a 36.2% improvement at −40 °C, while achieving a 28.4% enhancement in room-temperature wear resistance, thereby markedly elevating the overall performance of the material.