About Galvanized Steel
Our Light Duty Boltless Storage Racks use galvanized steel as its base material. Despite the fact that hot-dip galvanization was first practiced in the 17th century and subsequently widely applied by many industries, galvanized steel remains a mystery to many modern consumers.
What is Hot-dip Galvanizing?
It is the process of dipping steel into molten zinc to form a tightly-bonded alloy coating (galvanic coating) that provides corrosion, rust and scratch protection to steel.
During the reaction, the zinc interacts with the iron in the steel to form a series of zinc-iron alloy layers:
- A thin Gamma layer composed of an alloy that is 75% zinc and 25% iron
- A Delta layer composed of an alloy that is 90% zinc and 10% iron
- A Zeta layer composed of an alloy that is 94% zinc and 6% iron
- The outer Eta layer that is composed of pure zinc
Benefits of Galvanized Steel
Each layer possesses its own hardness, as expressed by the Diamond Pyramid Number (DPN) - a measure of hardness; the higher the number, the greater the hardness.
The image above shows a cross section of a a typical microstructure of galvanized steel coating. Gamma, Delta and Zeta layers are harder than the underlying steel. The hardness of these inner layers provides exceptional protection against coating damage by abrasion. The Eta layer is quite ductile, providing the coating with some impact resistance. Hardness and ductility combine to provide the galvanized coating with unmatched protection against damage caused by most forms of rough handling.
The use of galvanized steel provides maintenance-free longevity for decades, under normal atmospheric conditions. The corrosion resistance varies according to its surroundings, but generally corrodes at a rate of 20 - 30 times slower than bare steel in the same environment. That means if a piece of bare steel corrodes and rusts after a year, it will take at least 20 years for a similar piece of galvanized steel to react the same!
However, it is still not advisable to leave puddles of water or chemicals - that will take a long time to evaporate - on galvanized steel for a prolonged period of time as this causes the galvanic coating to be "eaten" away.
The prices of steel, zinc and galvanizing technology process have been relatively stable over the last 20 years, resulting in hot-dip galvanizing becoming more competitive, and often less expensive, than other corrosion protection system - such as aluminium and stainless steel.
- Aluminium is roughly 1.8 times more expensive than Galvanized Steel
- Stainless Steel is roughly 3 times more expensive than Galvanized Steel
With a tensile strength higher than Aluminium and comparable to Stainless Steel, Galvanized Steel is both cost-effective and highly-suited as base material for premium quality storage racks.