MANUFACTURE OF ELECTROPLATED STEEL SHEET HAVING FIXED AMOUNT OF DEPOSITED METAL

摘要

PURPOSE:To make the extend of deposition by plating uniform at all times by controlling the number of plating cells at the inlet side where an electric current is turned on or off so as to compensate increase or decrease in the extent of deposition by plating due to a change of a line speed before changing the line speed. CONSTITUTION:The number of plating cells at the inlet side where an electric current is turned on or off is successively controlled so as to compensate increase or decrease in the extent of deposition by plating due to a change of a line speed before changing the line speed. The electric current is successively turned on or off in the plating cells at the inlet side in accordance with the equation. In the equation, F is the coating weight (g/m<2>); K is a constant; Dmax is the upper limit of current density (A/dm<2>); L is the length of each electrode (m); y is plating efficiency; V1 and V2 are line speeds (m/min) before and after change; N1 and N2 are the number of cells through which a steel sheet is passed at line speeds V1 and V2, respectively; and Dmin is the lower limit of current density (A/dm<2>).