Process flow of cold rolled strip steel production

Cold Rolled Steel Strip Production Process

Cold rolled steel strip production process is a series of comprehensive processes including raw material selection, cold rolling and annealing, cut-to-length coil edge processing and surface inspection. Every process requires in-process control, product inspection and maintenance of necessary testing equipment. InThis article explains the cold rolling steel strip production process step by step.

Raw Material Selection

The first step in cold rolling steel strip is selecting the right raw material. Since cold rolled steel has higher production yield and higher cost relative to hot rolled steel, it is important that the raw material meets the specifications. It is important for the manufacturer to select high quality steel and have excellent surface quality to avoid product defects during production. In the selection process, technicians evaluate samples from the original billet, followed by microstructure analysis and determination of the required parameters, such as strength, toughness, elongation, and surface quality.

Cold Rolling

Once the raw material passes quality control, it is fed into the rolling mill where it is reduced in thickness and width. Cold rolling is a process that exerts pressure on the metal to reduce its thickness. The metal is fed between two rolls which are set at a gap between 3.2 to 8 mm depending on the strip thickness. The gap between the two rolls shifts and varies according to the desired strip width.In this process, the temperature of the roll increases due to continuous pressure on the metal strip, making it easier to roll the strip. The cold rolled steels undergo several passes through the rolling mill depending on the desired final thickness.

Annealing

After cold rolling, annealing is a process of reheating the metal to about 600°C and holding it for a certain time in a controlled atmosphere. This allows the steel to achieve its desired structure and gives it a higher resistance to stresses due to rolling. The heat treatment helps in softening of the metal strip, prevents cracking during the subsequent, stretching processes and also improves the surface finish.

Cut-to-Length Coil Edge Processing

The next step is cut-to-length coil edge processing which involves processing of the coil edges to ensure that they meet the required dimensional specifications. The edges are trimmed and sanded in order to produce uniform and consistent edges. This process is done by hand or mechanically with the help of special purpose machines depending on the requirements of the customer.

Surface Inspection

The surface of the cold rolled steel strips is inspected visually and mechanically to identify any surface defects, cracks and other imperfections. Any imperfection can be removed by grinding, polishing, shot blasting, and other processes. The degree of surface imperfections such as scratches and dents, if any, are recorded. This helps in determining whether the products meet the customer’s requirement for surface finish.

Conclusion

The cold rolled steel strip production process is a comprehensive process beginning from raw material selection to surface inspection. Each step is important to ensure that the end product meets the desired quality standards. Quality control and product specifications are of utmost importance in cold rolling steel strip production, as any flaws in the product will greatly reduce its value in the market.

Cold Rolled Strip Steel Production Process

Cold rolled strip steel production process is divided into hot rolling and cold rolled processes.

The hot rolling process includes a steel storage area, a shearer for cutting steel into strips, a roughing mill for milling the steel strips and a leveling machine for achieving a required surface finish. The steel storage area is used for stocking steel and cut the steel into strips. The shear for cutting the steel into strips is composed of different types of machines, including shear blades, sawing machines and shearing machines.

The roughing mill is used to remove the surface scale of the steel strips and to achieve the desired thickness, width and length of the products. The steel strips go through the rollers of the roughing mill, then the strips can be processed in the leveling machine. The leveling process is used to make the surface of the steel strips more uniform and smooth.

The cold rolled process is similar to the hot rolling process, except that only cold rolled mills are used. The key difference between hot rolling and cold rolling is that the latter uses cold rolling mills, which are designed to roll the steel at very low temperatures. The cold rolling mills use a process called annealing, which involves the use of heat, cold water, and chemicals to make the steel easier to work with and more reliable.

This process not only ensures a high-quality product, but also cuts down on the time and cost of production. Cold rolled strip steel is widely used for automotive, construction and other industrial applications. These materials provide strength and durability, making them essential for many manufacturing operations.