Grain-oriented electrical steel sheet having excellent magnetic characteristics and coating adhesion

A grain-oriented electrical steel sheet provided on its sheet surface with a tension-imparting type insulation coating constituted with a coating layer A formed on a steel sheet side and mainly composed of forsterite and a coating layer B formed on the coating layer A and mainly composed of a silicophosphate based glass containing one or more metallic elements selected from Mg, Al, Ca, Ti, Nd, Mo, Cr, B, Ta, Cu and Mn, characterized in that a ratio R (σB/σA) of a tension σB applied to the steel sheet by the coating layer B to a tension σA applied to the steel sheet by the coating layer A is within a range of 1.20-4.0.

A grain-oriented electrical steel sheet provided on its sheet surface with a tension-imparting type insulation coating constituted with a coating layer A formed on a steel sheet side and mainly composed of an oxide and a coating layer B formed on the coating layer A and mainly composed of glass, characterized in that a ratio R (σB/σA) of a tension σB applied to the steel sheet by the coating layer B to a tension σA applied to the steel sheet by the coating layer A is within a range of 1.20-4.0,

• wherein the grain-oriented electrical steel sheet is formed by subjecting a cold rolled sheet rolled to a final thickness to a secondary recrystallization annealing after a primary recrystallization annealing, wherein the primary recrystallization annealing comprises heating within a temperature range of 100° C. to 700° C. at a heating rate of not less than 50° C./s.