CR -FREE COATING SOLUTION, MANUFACTURING METHOD AND STEEL SHEET, MANUFACTURING METHOD

摘要

PURPOSE: A chrome-free coating solution, a manufacturing method thereof, an electric steel plate using the same and a manufacturing method of the electric steel plate are provided to reduce pollution and improve corrosion resistance and membrane tension by not including chrome oxide. CONSTITUTION: A manufacturing method of chrome-free coating solution for an electric steel plate comprises the following steps of: manufacturing colloidal silica first mixture solution by injecting and stirring hematite sol into colloidal silica; and manufacturing second silica-hematite- phosphate mixture solution by gradually injecting phosphate into the first mixture solution.