Steel Coils #2406924

Hot rolling is a mill process which involves rolling the steel at a high temperature (typically at a temperature over 1700 F), which is above the steels recrystallization temperature. When steel is above the recrystallization temperature, it can be shaped and formed easily, and the steel can be made in much larger sizes. Hot rolled steel is typically cheaper than cold rolled steel due to the fact that it is often manufactured without any delays in the process, and therefore the reheating of the steel is not required (as it is with cold rolled). When the steel cools off it will shrink slightly thus giving less control on the size and shape of the finished product when compared to cold rolled.

Cold rolled steel is essentially hot rolled steel that has had further processing. The steel is processed further in cold reduction mills, where the material is cooled (at room temperature) followed by annealing and/or tempers rolling. This process will produce steel with closer dimensional tolerances and a wider range of surface finishes. The term Cold Rolled is mistakenly used on all products, when actually the product name refers to the rolling of flat rolled sheet and coil products.

PPGI is pre-painted galvanised steel, also known as percolated steel, coil coated steel, colour coated steel etc.,

A galvanised steel sheet in coil form is cleaned, pre-treated, applied with various layers of organic coatings which can be paints, vinyl dispersions, or laminates. These coatings are applied in a continuous process known as Coil Coating. The steel thus produced in this process is a pre-painted, prefinished ready to use material. PPGI is the material which uses galvanised steel as the basic substrate metal. There could be other substrates such as aluminium, Galvalume, stainless steel, etc. Over 10 million tons of such coated steel is produced today in over 300 coating lines in the Globe.