HOT DIPPED GALVANIZING

THE HOT DIP GALVANIZING PROCESS   Unlike organic paint systems, a hot dip galvanized coating is produced by a metallurgical reaction between iron and the coating material i.e. molten zinc. A series of hard abrasion resistant iron/zinc alloys are formed and these are over-coated with relatively pure zinc as the product is withdrawn from the galvanizing bath. The various layers all play a significant role in the provision of corrosion protection. For the coating to form, the steel surface is required to be totally free from all contaminants such as mill scale, rust, grease and oil. As the name implies, the hot dip galvanizing process entails dipping or immersion into a series of cleaning and pre-treatment chemicals prior to immersion in the molten zinc. The advantage of this method is that all product surfaces are wetted uniformly, including areas which would be inaccessible for cleaning and coating by other methods.

Galvanizing entails the following operations: Inspection prior to galvanizing   Degreasing (dirt, paint and oil removal)   Acid Cleaning (rust and mill-scale removal)   Flux   Hot Dip Galvanizing   Quenching   Quality Control and Final Inspection