Improved magnetic properties of grain-oriented silicon steel by in-situ formation of potassium zirconium phosphate in insulating coating

In-situ formation of potassium zirconium phosphate (KZP) in the insulating coating for grain-oriented silicon steel has been prepared by roller coating technology and heat treatment. The microstructure, adhesion, corrosion resistance and magnetic properties for grain-oriented silicon steel coated with insulating coating featuring a range of KZP mass ratios have been investigated. Results indicate that the corrosion resistance and magnetic properties of grain-oriented silicon steel are improved by the in-situ formation of KZP when the mass ratio, m(KZP)/m(S0) is below 5/100. The lowest iron loss of 1.049 W/kg was obtained with m(KZP)/m(S0) of 3/100 and the highest magnetic induction intensity of 1.938T was achieved with m(KZP)/m(S0) of 1/100. The low thermal expansion coefficient of KZP is likely to contribute to extra tensile stress that improves corrosion resistance and magnetic properties for grain-oriented silicon steel.