Manufacturing method of directional electric steel sheet excellent in puncture property and interlayer insulation property

摘要

The present invention relates to a method for producing a grain-oriented electrical steel sheet used for an iron core of an electric machine such as a transformer, a generator and the like. In the method for producing a grain-oriented electrical steel sheet by the double cold rolling method, It is an object of the present invention to provide a method for manufacturing a grain-oriented electrical steel sheet excellent in both punching and release insulating properties by appropriately setting an insulating coating liquid.;The present invention relates to a method for producing a grain-oriented electrical steel sheet containing 3.5% or less of Si by a two-step cold rolling method, comprising the steps of: preparing a steel sheet having an oxygen partial pressure ratio of 0.001-0.01 in an atmosphere gas at a temperature range of 300-850C, And then continuously annealed at 930-1000C for 60-90 seconds and then subjected to final cold rolling followed by decarburization annealing to obtain 0.5-5.0% by weight of sodium sulfite or alkaline earth metal chloride , An annealing separator of MgO main component containing at least one of MgO, MgO, and MgO as a main component is applied, final annealing is performed, and the inorganic coating solution is applied in an amount of 1 to 3 g / The present invention relates to a method for producing a grain-oriented electrical steel sheet excellent in impact resistance and interlaminar insulation by applying 1-3 g / m 2 of a coating liquid.