Grain-oriented electromagnetic steel sheet with excellent coating properties and process for its manufacture

摘要

A high permeability grain-oriented electromagnetic steel sheet with a higher tension-imparting effect and more excellent cohesion and magnetic properties compared to the prior art, which also maintains sufficient corrosion resistance to withstand practical use; the grain-oriented electromagnetic steel sheet has on its surface an insulation coating comprising a first layer composed mainly of a divalent or trivalent metal hydrogen phosphate salt and silica, and a second layer composed mainly of aluminum borate and having a surface roughness of 0.1 mu m - 0.35 mu m in terms of Ra (center line average roughness).