ELECTROLYTIC GALVANIZING PROCESS WITH CONTROLLED CURRENT DENSITY

摘要

ABSTRACT OF THE DISCLOSURE:Disclosed is an electrolytic galvanizing process which, dueto its very specific conditions of operation, permits one toobtain a highly compact deposit, with good corrosionresistance and surface appearance. The process is based onthe discovery that there exists a precise relationshipbetween the current density and the fluid dynamicsconditions of the electrolyte and comprises the steps ofcontinuously passing the body to be coated with zinc throughan acid electrolytic solution containing zinc ions in acell, passing electrolytic solution through the spacedefined between an anode and said body serving as a cathode,and adjusting the plating current density, the fluid dynamicconditions of the electrolytic solution or both of saiddensity and fluid dynamic conditions so as to substantiallysatisfy the relationship defined by the formulaI = K C Renwhere I is the current density in A/dm2' C is the zincconcentration in g/l, Re is the Reynolds numbercharacteristic of the electrolytic solution flow, and K andn are empirical variables depending essentially on thegeometry of the cell, wherein K is in the range from 10-2 to10-6, and n is in the range from 0.5 to 1.