The manufacturing process of the cold-rolled steel coils can be divided into the following steps.

#1 Cold rolling

The thickness accuracy of cold-rolled products is determined by the cold rolling process. Rolling force and strip tension are computer-controlled to minimize thickness deviations during rolling, based on measurements of the strip thickness at the entry and delivery sides of the mill.

#2 Cleaning

Rolling oil on the cold-rolled strip is burned off during annealing, which is the next process after cold rolling. Other types of rolling oil are removed by electrolytic cleaning prior to annealing. In particular, electrolytic cleaning is used with products which require a clean surface to ensure good paintability.

#3 Annealing

The formability of products is determined by annealing. Because cold rolling significantly increases material hardness, making forming difficult, annealing is performed to improve ductility by inducing a recrystallized structure in the steel. As the annealing process, steel coils are piled and covered by the box and annealed and this is called the batch annealing. The other is the continuous annealing process, in which coils are continuously treated. ADTO GROUP uses two annealing technologies, depending on product requirements.

#4 Skinpass rolling

Annealed coils are lightly rolled by the skinpass mill to prevent a defect called stretcher strain, improve strip shape, and adjust mechanical properties. Skinpass rolling is also used to produce a dull finish and bright finish products.

#5 Finishing

After skinpass rolling, steel coils are processed at the recoiling line, where they are cut to produce product coils of the specified weight, or at the shearing line, where they are cut to sheets of the specified dimensions. Product thickness, width, shape, and surface quality are inspected, and mechanical properties are tested using specimens taken at the finishing line.

ADTO GROUP manufactures steel sheet & steel coils for sale. We are the leading supplier of building materials in China. For further information about cold rolled steel coil, pls. Feel free to contact us.