PROCESS FOR PRE-TREATING CAN MATERIALS FOR LACQUERING

摘要

The present invention comprises a process for pre-treating a steel strip intended for can making in the lacquring line in an electrolysis tank containing as the treating solution more than 50g/l of anhydrous chromic acid and sulfate ions in the amount of 2 to 5% of the anhydrous chromic acid, electrolytically treating the steel strip less than 0.2 sec. at a current density of 50 A/dm2 on the downward path in the tank, then dissovling the excessive part of attached hydrated oxide of chromium on the upward path and immediately applying lacquer. The chemical treatment process of the present invention is very easily connected to the lacquring line for steel strips, and thereby lacquered can materials possessing excellent anti-under-film corrosion and suitable for cans for carbonated beverages are supplied with decreased cost.