WHAT IS GALVANIZING?
Galvanizing is the process of inter-metallic bonding between steel with zinc, resulting in a corrosion-resistance protection of up to 50 years. It is one of the most widely-used and effective methods of corrosion protection.
BENEFITS OF HOT-DIP GALVANIZING
Galvanizing is generally more cost-effective for long term protection when compared to other form of coatings.
Total immersion, Complete protection
The uniform protection of hot-dip galvanized steel leaves no weak points for accelerated corrosion, coating from the inner to outer surfaces.
Galvanized coatings are virtually maintenance-free with a long service life.
The cathodic protection from galvanizing is constant even in the toughest environment, rendering it a preferred choice for corrosion protection in a wide range of industries.
Galvanized coatings are tough and not easily damaged by abrasion, during transport, erection and throughout the service life of the steel.
The anti-corrosion layers are also known to protect the underlying steel for over 50 years!
The process of galvanizing typically follows:
Pre-treatment surface preparation -> Galvanizing immersion -> Finishing
One of the most important steps in Hot Dip Galvanizing is the surface preparation of the steel. As the galvanizing process is a metallurgical reaction, which can only occur between a clean steel surface and the molten zinc, it is critical that the material is to be properly prepared. Inadequate surface preparation will result in uncoated areas.
Pre-treatment (usually) consists of degreasing, acid pickling, followed by pre-fluxing.
A water-rinsing step is also incorporated between degreasing and acid pickling, and between the pickling and pre-fluxing.
After the thorough washing process, the jig is placed in the dryer to attune the material to a temperature better ready for the hot molten bath. Sequentially, the jigs will enter then enter the galvanizing kettle containing molten zinc around the temperature of 449°C.
This marks the beginning of the corrosion resistance of up to 50 years.
The finishing department receives the freshly galvanized steel to do some finishing touches such as the removal of zinc spikes. After this, your material will be ready for collection - as simple as that!
image from: Figure 1: Model of the Hot-Dip Galvanizing Process, https://www.galvanizeit.org/inspection-course/galvanizing-process