S. Huang; Z. An; S. Liu; S. Cao; S. Wang; Z. Wang; M. Qu; Z. Xu; C. Huang; H. Huang
SSRN 5334831
A novel hot-rolling deposition process using SiO2-B2O3-Na2CO3 composite powders
was developed to enhance the tribological performance of A709Gr50 structural steel.
This process produced a dense, nearly defect-free Fe3O4/xSiO2-yB2O3-zNa2O
composite 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