Coloration treatment manner and coloration melting galvanize steel null spelter

摘要

PURPOSE: To provide a method for painting the surface of the hot dip galvanized steel of a steel structure such as power-transmission steel tower and bridge a color in harmony with the spectacular sight and to furnish a colored hot dip galvanized steel treated by the method. ;CONSTITUTION: A zinc, a zinc alloy, an electrogalvanized steel or a hot dip galvanized steel is dipped in a first soln. prepared by adding sodium hydroxide (yg/l) to potassium permanganate (xg/l), where satisfy the equations, y≥40, y≥-8x+200 and y≤1.15x+1.40, to color the zinc surface and then washed with water. The colored material is subsequently dipped in a second soln. prepared by mixing 0.5-5g/l sodium bichromate and 25-100g/l cobalt sulfate to impart corrosion resistance.;COPYRIGHT: (C)1996,JPO