What is the difference between hot-rolled steel, cold rolled steel, galvanized steel, stainless steel and color coated steel?
1. Hot rolled steel (HR)
Hot rolled steel plates are produced from billets that are typically challenging to shape and work with at room temperature. To facilitate the rolling process, they are typically heated to temperatures ranging from 1100 to 1250 ℃. This method of rolling is referred to as hot rolling, and the steel plates that are obtained through this process are known as hot rolled plates.
2. Cold rolled steel (CR)
Cold rolling is a process in which hot rolled steel is rolled at room temperature. This process is used to produce cold rolled steel plates, also known as cold plates. The thickness of cold rolled steel plates typically ranges from 0.1 to 8.0mm, with most factories producing plates less than 4.5mm in thickness.
3. Galvanized steel
Galvanized steel is produced by applying a layer of zinc onto the surface of cold steel.
3.1 Hot dip galvanized steel (HDG)
Hot-dip galvanized sheet is produced by dipping a thin cold-rolled sheet into a molten zinc pot, which creates a layer of zinc on the surface of the steel sheet. This process helps to protect the steel from rust and corrosion, making it suitable for use in a variety of applications, including automotive parts, construction materials, and household appliances.
Traditionally, the difference between hot-dip galvanizing and cold galvanizing was identified by the presence or absence of zinc spangle. However, modern production methods now allow for the production of hot-dip galvanized steel without spangle, thanks to the addition of zinc spangle inhibitors during the galvanization process.
4. Stainless steel
Galvanized steel plate is protected against rust by plating a layer of zinc, while stainless steel is protected against corrosion by adding alloy. It is divided into different grades according to the alloy composition. The common grades are 201, 304, 316 ,410 and 430.
5. Color coated steel (PPGI&PPGL)
Color coated steel plate is a type of steel plate that is coated with a layer of paint, and is commonly used in the construction of roofs and walls. The most commonly used substrates for color coated steel plates are galvanized plates and aluminum zinc plates, although some manufacturers also use aluminum plates and stainless steel plates. The most commonly used types of paint for color coated steel plates are PE and PVDF, with PVDF offering better weather resistance. In addition to solid colors, color coated steel plates can also be produced with surfaces that mimic the appearance of stone, wood, and other patterns.
6. Aluminum sheet
Besides the above-mentioned steel plates. The aluminum sheet are a commonly used type of metal plate that can sometimes be used as a substitute for galvanized and stainless steel plates. Compared to steel plates, aluminum plates are lighter in weight and have better corrosion resistance. Pure aluminum is relatively soft, but its mechanical properties can be improved through the use of different alloys.