What is the code for galvanised steel?

Galvanised steel, also known as galvanized steel, is a type of steel that has been coated with a layer of zinc to protect it from corrosion. The process of galvanisation involves applying a protective zinc coating to the surface of the steel through either hot-dip galvanisation or electroplating.

Hot-Dip Galvanisation

Hot-dip galvanisation is the most common method used to coat steel with a layer of zinc. In this process, the steel is immersed in a bath of molten zinc at a temperature of around 450°C. As the steel is taken out of the bath, the zinc reacts with the oxygen in the air to form a protective layer of zinc oxide on its surface. This layer further reacts with carbon dioxide to form a layer of zinc carbonate, which provides additional protection against corrosion.

Electroplating

In the electroplating process, a thin layer of zinc is deposited onto the steel surface using an electric current. The steel is first cleaned and then immersed in a solution containing zinc ions. When an electric current is passed through the solution, the zinc ions are attracted to the steel surface and bond with it, forming a layer of zinc coating. This method is often used for smaller, more intricate steel objects.

Codes for Galvanised Steel

When referring to galvanised steel in technical specifications or standards, it is usually identified by specific codes. These codes are provided by various national and international organizations, such as ASTM International, EN (European Norms), and ISO (International Organization for Standardization).

For example, the American Society for Testing and Materials (ASTM) provides several codes for galvanised steel, including ASTM A123/A123M for zinc coating on iron and steel hardware and ASTM A653/A653M for steel sheet, zinc-coated (galvanized) or zinc-iron alloy-coated (galvannealed) by the hot-dip process. Similarly, EN 10346 in Europe and ISO 3575 worldwide provide codes for galvanised steel in different applications.

These codes ensure that galvanised steel products meet specific requirements for corrosion resistance, durability, and other properties. They also help manufacturers, engineers, and customers in selecting the appropriate galvanised steel products for their intended applications.