Application of Rare-earth/Zn/Al Alloy to Processing of Hot-dip Galvanized Steel Tube

A new process concerning adding trace rare earth/Zn/Al alloy into the hot galvanizing solution is developed by Changchun Steel Tube General Plant to reduce zinc consumption and enhance corrosion resistance of the hot-dip galvanized steel tube for greater economic benefit. The article involves main aspects of the said steel tube galvanization process with addition of rare earth/Zn/Al alloy technique, including process flow, the results of coating uniformity test and salt frog test of the alloy-galvanized tube and relevant economic analysis. Thanks to use of the rare earth/Zn/Al alloy, the following advantages have been achieved:improved mobility of the coating alloy metal, reduction of coating thickness by 18%-20%, reduction of zinc consumption by 10%, doubled or even tripled corrosion resistance and zinc saving of 8.2 kg, per ton of tubes.