A metal composition which contains iron is a Ferrous Metal.
Eg. Steel, Alloy Steel, Cast iron,
Ferrous Metals are Magnetic in nature.
Ferrous metals have carbon in their composition, due to which when Ferrous metals are exposed to moisture/humidity it rust.
Higher carbon presence make iron harder.
Stainless Steel is made harder by addition of carbon, And to protect it from rust chromium and nickel are added.
A metal composition which does not contain iron is a Non Ferrous Metal. Eg. Copper, Aluminium, Lead, Zinc, Tin.
Non Ferrous Metals are Non Magnetic in nature.
Since Non Ferrous metals, do not have iron content, which gives them higher resistance to corrosion.
CRCA : Cold Rolled Close Anneal
To Reduce Sheet thickness, Cold Rolling is done after Hot Rolling and Pickling of the Steel.
Cold Rolling increases the metal Hardness.
GI : Galvanized Iron
HDG : Hot Dip Galvanized
By dipping Iron/Steel Sheet into Molten Zinc, it gives protective buffer to iron from Moisture/Oxygen.
Zinc provides cathodic protection to steel sheet
Galvanization is the process, where Steel Sheet are dipped in Molten Zinc. Zinc coating provides Physical Barrier and Cathodic Protection to the Sheet Steel. Zinc Metallic Barrier prevents moisture to reach upto Steel, hence protection against corrosion, This Metallic Barrier has long life, which is directly proportional to its thickness.
Zinc provides Cathodic Protection, if there is scratch on Steel sheet, its protected by Sacrificial loss of Zinc near to exposed steel, which ensures there is no Corrosion till all the zinc is sacrificed.
While manufacturing Enclosure for Electrical Panel, Pre Enclosure manufacturing Galvanizing gives economy, While Post Enclosure manufacturing ensures there is no Bare Edges are left from Galvanization.
Zinc layer on the Iron, acts as sacrificial metal. Zinc layer when combine with Oxygen, it forms Zinc-Oxide layer, which prevents formation of Iron-Oxide, there by preventing Corrossion.
GI : Galvanized Iron
CRCA : Cold Rolled Close Anneal
CRCA sheets can be Galvanized.
Cold Rolling is Technique to form the steel.
HDG-Galvanization is treatment on steel sheet to protect it from corrosion.
GI has better Corrosion Resistance compared to bare CRCA sheet.
If GI sheet is damaged to Scratched, Zinc layer will ensure protection for the surface against corrosion.
CRCA can be Galvanized, this will give advantages of both CRCA and Galvanization.
In this Process of Galvanization, Sheet Metal is submerged into molten Zinc tank. With this process Fe-Zn alloy layer is formed on the Surface, which provides Physical Barrier and Cathodic Protection to the Sheet Steel. This Process is double expensive than Electro Galvanization process. This Process offers very high corrosion resistance life to Sheet steel of 30 + years.
In this Process of Galvanization, Sheet Metal is submerged into Zinc solution, where Zinc Solution is given Anode charge and Sheet Steel is Cathode charge.
With the help of Anode – Cathode reaction, layer of Zinc is bonded to Sheet Steel. This process very economical than Hot Dip Galvanization. This process offers short corrosion resistance life to Sheet steel of around 5 + years.
Galvanization is the process, in which Steel Sheet are dipped in Molten Zinc.
Powder Coating is the Process, in which Steel sheet is surface treated with phosphating and then Epoxy Powder coated.
If there is no Mechanical Abrasion, Powder Coating life can be similar to Galvanization, But if there is a damage and Steel is Exposed, it will rapidly rust.
Layer of Zinc will be harder to scratch than Paint.
Zinc coating provides Physical Barrier and Cathodic Protection to the Sheet Steel.