1. Surface condition: Due to different treatment methods in the coating process, the surface conditions of galvanized sheets are also different, such as ordinary zinc flowers, fine zinc flowers, flat zinc flowers, no zinc flowers, and phosphated surfaces. German standards also specify surface grades.
2. The galvanized sheet should have good appearance and should not have defects that are harmful to the use of the product, such as no plating, holes, cracks and scum, excessive plating thickness, scratches, chromic acid dirt, white rust, etc. Foreign standards are not very clear on specific appearance defects. Some specific defects should be listed in the contract when ordering.
Chemical composition of galvanized sheets
The requirements for the chemical composition of galvanized sheet substrates vary from country to country. National standards generally test the content of carbon, manganese, phosphorus, sulfur, and silicon.
Consumption status of galvanized sheets
The increase in domestic galvanized sheet production is mainly due to the increase in hot-dip galvanized sheet production. From 1998 to 2002, hot-dip galvanized sheet production increased from 970,000 tons to 2.2 million tons; while imports grew faster, from 1998 to 2002. 370,000 tons increased to 1.56 million tons in 2002; apparent consumption increased from 1.32 million tons to 3.67 million tons. In 2002, the domestic product self-sufficiency rate of hot-dip galvanized sheets was about 60%. The domestic production and import volume of hot-dip galvanized sheets that year both increased compared with the previous year. In particular, the import volume increased even more, mainly due to the supply of hot-dip galvanized sheets. The increased demand for thin-gauge hot-dip galvanized sheets used in the production of color-coated sheets has led to a decline in the domestic product self-sufficiency rate.
Advantages of galvanized sheets
1. Robustness. When galvanized sheets are used as wall decorations, they will not be dented or scratched on the surface due to external impacts, whether during transportation or later use.
2. Moisture-proof and durable. The galvanized sheet material will not be affected by environmental weather and will not become moldy or damp during use, so that the product performance will not be affected.
3. Anti-rust and anti-corrosion. A layer of zinc is attached to the surface of the galvanized sheet, which can form an antioxidant layer on the surface of the steel, increasing the corrosion and rust resistance of equipment, machines and other parts, effectively extending the service life of the product.
4. Construction is quick and convenient. Galvanized sheets save time and effort during construction and installation compared to other materials. After installation, they can be put into use without on-site painting.
5. Strong plasticity. Galvanized sheets can be processed in different ways, such as stamping, rolling and arbitrary bending as needed to meet different requirements.
6. Good heat resistance. Most materials can only withstand temperatures within 230 degrees, otherwise there will be deformation and discoloration. Galvanized sheets can endure a high temperature of about 310 degrees for 120 hours without discoloration or deformation.
