How to Distinguish Between Hot Rolled and Cold Rolled Steel?

Hot Rolled Steel and Cold Rolled Steel both are steel products, but they differ in their manufacturing process, properties, and applications.

Hot rolled steel coil

Hot Rolled Steel is produced by heating the steel to its re-crystallization temperature, which is approximately 1700°F, then rolling it to the desired thickness. The steel is then allowed to cool to room temperature. The process of hot rolling steel results in a surface finish that is relatively rough, with a scale-like appearance.

Cold rolled steel coil

Cold Rolled Steel is produced by cold reducing the hot rolled steel to the desired thickness at room temperature, followed by annealing and tempering. This process results in a smoother surface finish and improved dimensional accuracy, as well as increased mechanical properties compared to hot rolled steel.

You can distinguish between hot rolled steel and cold rolled steel in the following ways:

Surface Finish

The surface of Hot Rolled Steel is relatively rough, with a scale-like appearance, while the surface of Cold Rolled Steel is smoother and more precise, with a uniform finish.

Dimensional Accuracy

Cold Rolled Steel has better dimensional accuracy compared to Hot Rolled Steel, as the process of cold rolling allows for better control over the final product's thickness, width, and length.

Mechanical Properties

Cold Rolled Steel typically has higher strength and hardness compared to Hot Rolled Steel, as the process of cold rolling improves the steel's mechanical properties.

Cost

Hot Rolled Steel is typically cheaper than Cold Rolled Steel due to the lower production cost of the former.

Applications

Hot Rolled Steel is used in applications where dimensional accuracy and surface finish are not critical, such as in the construction industry, while Cold Rolled Steel is used in applications where dimensional accuracy and surface finish are critical, such as in the automotive and aerospace industries.

In summary, both hot rolled steel and cold rolled steel are important products for the steel industry, each with its own unique properties and applications. The differences between the two are mainly in dimensional accuracy, surface finish and mechanical properties.

If you want to know more information about hot rolled steel and cold rolled stee, please contact us. We will provide professional answers.