| 摘要 |
PURPOSE:To obstruct the hot dipping of one side of a steel plate and to facilitate removal of the obstructing coating after plating, by coating one side of the steel plate with MgO having a prescribed value of BET showing a specific surface area as an obstructing agent for hot dipping. CONSTITUTION:One side of the steel plate is coated with the obstructing agent for hot dipping having MgO having a value of BET of 10-70m<2>/g, Na2OSiO2, H3BO3, NaOH, etc. dispersed in water. After the coating, drying and annealing are carried out, and then the steel plate is dipped into a fused zinc bath. Subsequently, the steel plate is drawn up from the plating bath and then it is dipped into water and rapidly cooled to peel off the coating. The process provides a steel plate having one side not hot-dipped completely and the other side hot-dipped with zinc. |
