Wet storage stain describes the white, generally powder-like substance which can form on the surface of a galvanized article. It can also create black spots on the surface during initial development and generally consists of natural zinc corrosion products, such as zinc oxide and zinc hydroxide.

It’s important to note that the main difference between hot rolled and cold rolled steel is one of process. “Hot rolling” refers to processing done with heat. “Cold rolling” refers to processes done at or near room temperature.

The corrosion of structural steel is an electrochemical process that requires the simultaneous presence of moisture and oxygen. Essentially, the iron in the steel is oxidised to produce rust, which occupies approximately six times the volume of the original material.

Understanding Corrosion and How to Protect Against It. To make the use of steel and other metals practical in construction and manufacturing, some corrosion-protection practices must be employed.