1.What is the uncoiling and welding process like?
The steel coil is unwound to provide steel strip for continuous production. At the same time, the tail of the preceding strip is welded to the head of the following strip to ensure the continuous operation of the unit.
2.What are the steps for degreasing and cleaning?
Through a series of operations such as spraying, brushing, and electrolytic cleaning, rolling oil, iron powder and other impurities on the surface of the strip are removed to obtain good coating adhesion and surface quality. After cleaning, it is squeezed dry and dried with hot air.
3.How does the annealing process work?
Recrystallization annealing is performed on rolled hardened strip to obtain good mechanical properties. Annealing furnaces generally consist of several stages, including preheating, heating, soaking, and cooling. By controlling the atmosphere within the furnace, good strip coating properties can be achieved.
4.What are the steps of hot-dip galvanizing process?
The annealed steel strip is immersed in a molten zinc bath to deposit a layer of zinc on its surface. Currently, the primary process used is a continuous galvanizing process, where the strip is continuously immersed in a bath containing molten zinc. During the galvanizing process, an air knife is used to spray gas (usually air or pure nitrogen) onto the strip's surface after it exits the zinc bath to control the thickness of the coating.
5.How to handle leveling and straightening?
The strip is rolled at a low rolling force, also known as leveling, to eliminate the yield plateau of low-carbon steel, improve strip properties, and obtain the desired strip surface roughness. After leveling, the strip is stretched and straightened to obtain a good plate shape.