METHOD OF PREVENTING POLLUTION IN WASHING COLD-ROLLED STEEL SHEET AND STRIP WITH IMIDAZOLE

摘要

PURPOSE: A method of preventing pollution in washing a cold-rolled steel sheet and strip with imidazole is provided to prevent the surface of a cold-rolled steel sheet and strip from discoloring in an alkali/electrolytic cleaning tank with imidazole. CONSTITUTION: In a process of degreasing a cold-rolled steel sheet and strip, about 0.1-0.2wt% of imidazole is added on the basis of the total weight of an alkali degreasing solution into an alkali/electrolytic cleaning tank. Therefore, the cold-rolled steel sheet and strip is prevented from pollution in washing the steel sheet and strip in the alkali/electrolytic cleaning tank.