Treatment liquid for chromium-free tension coating, method for forming chromium-free tension coating, and method for producing grain-oriented electrical steel sheet with chromium-free tension coating

摘要

Providing a treatment solution for chromium-free tension coating that can simultaneously achieve excellent moisture absorption resistance and high iron loss reduction effect by applying sufficient tension without using expensive Ti chelate. To do. A treatment liquid for chromium-free tension coating, one or more selected from Mg, Ca, Ba, Sr, Zn, Al, and Mn phosphates. In contrast, 50 to 120 parts by mass of colloidal silica in terms of SiO2 solid content, the phosphate: containing 30 to 50 parts by mass of Ti source in terms of TiO2 and 100 parts by mass of H3PO4, A treatment liquid for chromium-free tension coating, wherein the number of moles of the metal element and the number of moles of phosphorus in the treatment liquid satisfy the relationship of the following formula (1). 0.20 ≦ ([Mg] + [Ca] + [Ba] + [Sr] + [Zn] + [Mn] +1.5 [Al]) / [P] ≦ 0.45 (1)