The influence of rare earth elements (Y, Sc) on the interfacial binding properties between the precipitation phases Fe2B, FeB and the matrix Fe in boron steel

Abstract

Boron steel is a commonly used wear-resistant material in the metallurgical and mining industries. The performance of its hard precipitated phases and their coordination with the matrix are currently the main focus of attention. In this paper, the mechanical properties of the precipitated phases in boron steel were studied using first-principles calculations. Fe2B and FeB have high hardness, and the low-index surfaces with the lowest surface energy are (111). The low-index surface of the matrix Fe is (110). The interfacial properties between the matrix and the precipitated phases (Fe2B and FeB) were calculated. The interfacial energy of Fe(110)/FeB(111) is 0.3113 eV/Å2, and the interfacial energy of Fe(110)/Fe2B(111) is 0.3987 eV/Å2. The effects of rare earth elements Y and Sc on the interface bonding strength between (Fe2B, FeB) and matrix Fe were also examined. It was found that Y-doped Fe(110)/FeB(111) interface is more stable than that doped with Sc; however, the Sc-doped Fe(110)/Fe2B(111) interface is more stable than that doped with Y. The above calculation results indicate that rare earth elements play a promoting role in the micro-interface of boron steel, and the coordination between the precipitated phases and the matrix significantly improves the wear resistance of boron steel.