S. Huang; Z. An; S. Liu; S. Cao; S. Wang; Z. Wang; M. Qu; Z. Xu; C. Huang; H. Huang
Materials Characterization 229 (2025) 115658
Hot-rolled structural steels are widely used in marine, mining and energy industries, but they are often sus
ceptible to surface damage from abrasive wear owing to low hardness. In this work, a novel hot-rolling depo
sition process using SiO2-B2O3-Na2CO3 composite powders was developed for A709Gr50 structural steel to
enhance its wear resistance. This process produced a dense, nearly defect-free Fe3O4/xSiO2-yB2O3-zNa2O com
posite coating, with crack density and porosity controlled by the SiO2 to Na2CO3 mass ratio. The dominant phase
in the coating was a sodium borosilicate-like glass (xSiO2-yB2O3-zNa2O), formed through vitrification of the
precursor powders during rolling. Thermal diffusion of Fe from A709Gr50 substrate into the molten glass led to
the formation of Fe3O4 dendrites, which chemically bonded with the steel. Additionally, Fe3O4 precipitates
formed within the glass matrix via mechanical interlocking. The resulting composite coating exhibited wear
resistance 14.7 times greater than the base steel, attributed to the presence of high-hardness Fe3O4 in the contact
area and a robust coating-substrate interface.
DOI: https://doi.org/10.1016/j.matchar.2025.115658