Product Process
The production of galvalume coil steel begins with steel billets that are sent to the hot rolling process and rolled into plates of a certain thickness, typically around 10mm. When there are no stringent requirements for surface finish, thickness tolerance, or mechanical strength, the hot-rolled plates can be directly used or sold as hot-rolled sheets.
For applications requiring higher standards, the hot-rolled plates are further processed on the cold rolling line. This involves pickling to remove surface oxides, annealing to improve ductility, and repeated rolling to achieve the desired final thickness. The resulting cold-rolled sheets feature a thinner gauge, smoother surface, and superior mechanical properties, providing an excellent base for subsequent galvalume coating.
Main Applications
Galvalume coil steel is widely valued for its excellent corrosion resistance and durability. In the construction and decoration industry, it is commonly used for roofing, wall cladding, ceiling systems, and curtain wall decoration. Its superior weather resistance makes it suitable for factories, commercial buildings, warehouses, and residential projects in various environments.
Product Category Specifications
Common specifications include curtain wall panels, embedded plates, and various galvanized/galvalume steel sheets. Typical sizes range from thickness 6-16mm, with widths and lengths commonly between 100-300mm (such as 6×100×100, 6×150×150, 8×150×150, 8×200×200, 8×200×250, 8×200×300, etc.). Custom dimensions are available according to project requirements.
Galvalume coating has become one of the most important anti-corrosion methods for steel products. In addition to forming a dense protective layer on the steel surface, the aluminum-zinc alloy provides excellent cathodic protection. Even if the coating is slightly damaged, it can still effectively protect the underlying steel substrate from corrosion.
Surface State
The surface condition of galvalume coil steel varies depending on the treatment process during production. Common surface types include regular spangle, minimized spangle, smooth finish, and phosphate-treated surfaces. Relevant international standards (such as ASTM and EN) also define different surface grades to meet diverse customer needs.
Quality Requirements
High-quality galvalume steel coils should have a clean and uniform appearance, free from defects that could affect usage, such as missing coating, holes, cracks, excessive coating thickness, scratches, white rust, or other surface imperfections. When placing orders, specific quality requirements and acceptable defect levels are usually clearly stated in the contract to ensure the material meets the intended application standards.
