What is cold rolled steel coil？

Cold-rolled steel is made from hot-rolled coils, pickled to remove oxides, and then continuously cold-rolled to produce the finished product.

Cold-rolled coils are made from hot-rolled coils and are supplied in coils after pickling, cold rolling, bell annealing, flattening, and finishing.

Continuous cold deformation causes work hardening, which increases the strength and hardness of the hardened coils while decreasing their toughness and ductility. This degrades their stamping properties, making them suitable only for parts requiring simple deformation. Cold rolling is a process in which hot-rolled steel is processed at room temperature. Although the steel heats up during the rolling process, it is still called cold rolling.

Cold-rolled Steel Plate Dimensions

1. Standard Thickness (mm)
Ultra-Thin Plate: 0.2, 0.3, 0.4, 0.5

Conventional Plate: 0.6, 0.8, 1.0, 1.2, 1.5, 2.0, 2.5, 3.0

Medium Plate: 3.5, 4.0, 5.0, 6.0

2. Common Widths (mm)
Narrow Width: 600, 800, 1000
Standard Width: 1250, 1500
Wide Width: 1800, 2000mm

3. Length (mm)
Fixed Length: 1000, 2000, 2500, 3000, 6000

4. Material Types (Common Standards)

Chinese Standards (GB): SPCC (Cold-rolled Carbon Steel for General Purpose), SPCD (Cold-rolled Carbon Steel for Stamping), SPCE (Cold-rolled Carbon Steel for Deep Drawing)

Japanese Standards (JIS): SUS304 (Cold-rolled Stainless Steel), SGCC (Galvanized Cold-rolled Steel)

American Standards (ASTM): A1008 (Commercial Cold-rolled Carbon Steel), AISI 1010/1020 (Low-carbon Cold-rolled Steel)

Cold-rolled Steel Properties

1. Cold-rolled steel sheets offer uniform thickness and can fully meet the requirements of high-precision public services on a commercial scale.

2. Extremely thin strip, which cannot be produced with hot rolling, can be produced, with thicknesses down to 0.001mm.

3. Cold-rolled steel coils offer superior surface quality, free of defects commonly found in hot-rolled coils, such as pitting and pressed-in scale. Rolls with varying surface roughness can be manufactured to meet customer requirements, facilitating subsequent processing.

4. Cold-rolled steel sheets offer superior coil length and excellent mechanical and process properties, including higher strength, lower yield strength, and outstanding deep-drawing performance.

5. High-speed and fully continuous rolling are possible, resulting in a high yield rate.

Cold-rolled Steel Sheet Process

1. Process lubrication and cooling are used to reduce deformation resistance during rolling and cool the rolls.

2. High-tension rolling is used to reduce deformation resistance and maintain rolling stability. The average unit tension used is 10% to 60% of the material's yield strength, generally not exceeding 50%.

3. Multi-roll rolling is used. Because cold rolling causes work hardening in the material, further deformation becomes difficult when the total deformation reaches 60% to 80%. Therefore, intermediate annealing is performed to soften the material before further rolling. Multiple such intermediate annealing processes can be performed to achieve the desired thin strip. The rolling process between two intermediate annealing processes is called a rolling pass. The minimum thickness of cold-rolled strip can reach 0.05mm, and that of cold-rolled foil can reach 0.001mm.

Advantages of cold-rolled coil:

1. Excellent Surface Quality: Cold-rolled coil undergoes multiple rolling and surface treatments, resulting in a smooth surface finish free of inclusions and microcracks, making it suitable for the production of products requiring high surface quality.

2. High Thickness and Dimensional Accuracy: The thickness and dimensions of cold-rolled coil can be more accurately controlled during the rolling process, resulting in a more uniform and dimensionally stable product, facilitating subsequent processing and use.

3. Excellent Mechanical Properties: The denser crystalline microstructure of cold-rolled coil results in higher hardness and strength, as well as excellent wear resistance and tensile strength, making it suitable for use in complex working conditions.

4. Excellent Processability: Cold-rolled coil is easy to form, cut, and weld during subsequent processing, offering excellent processability and meeting diverse processing requirements.

Due to its numerous advantages, cold-rolled coil is widely used in modern industrial production. In automotive manufacturing, cold-rolled coiled steel is used to manufacture car bodies, chassis, and components, improving vehicle safety and reliability. In the construction industry, cold-rolled coiled steel is used to produce various structural steels, enhancing the load-bearing capacity and stability of buildings. In electronic product manufacturing, cold-rolled coiled steel is used to produce components such as housings and connectors, ensuring product stability and quality.

What are the uses of cold-rolled steel sheet?

Because it is rolled at room temperature, no scale forms. Therefore, cold-rolled steel sheet has excellent surface quality and high dimensional accuracy. Combined with annealing, its mechanical and processing properties surpass those of hot-rolled steel sheet. Cold-rolled steel sheet has gradually replaced hot-rolled steel sheet in many fields, particularly in home appliance manufacturing.

Cold-rolled steel has a wide range of applications, including automotive manufacturing, electrical appliances, rolling stock, aviation, precision instruments, and food canning. Cold-rolled steel sheet is the abbreviation for cold-rolled ordinary carbon structural steel sheet, also known as cold-rolled sheet, commonly known as cold plate, and sometimes mistakenly written as cold-rolled sheet. Cold plate is made of ordinary carbon structural steel hot-rolled steel strip, which is further cold-rolled into steel plate with a thickness of less than 4mm.