The chrome free insulating coat treatment liquid for the directivity electromagnetic steel sheet which features that it contains above the 1 or 2 kinds which are chosen from inside

摘要

PROBLEM TO BE SOLVED: To provide an insulation-film treatment liquid free from chromium for a grain-oriented electromagnetic steel sheet, which prevents the lowering of its film tension and moisture absorption resistance, which is a problem occurring when the insulation-film treatment liquid does not contain chromium, and which gives properties required for the insulation film of a grain-oriented electromagnetic steel sheet, specifically, film tension, moisture absorption resistance, corrosion resistance and a space factor equivalent to those in an insulation film obtained by using an insulation-film treatment liquid containing a chromium compound, to the insulation film.;SOLUTION: This treatment liquid includes: one or more phosphates selected from the phosphates of Mg, Ca, Ba, Sr, Zn, Al and Mn; and colloidal silica in an amount of 0.5 to 10 mol in terms of SiO₂ and a water-soluble vanadium compound in an amount of 0.1 to 2.0 mol in terms of V with respect to 1 mol of the PO₄ which is contained in the above selected phosphate and shall be a reference value.;COPYRIGHT: (C)2009,JPO&INPIT