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Hot Rolled Steel vs Cold Rolled Steel – What’s the Difference

Stainless steel is present in various grades, specifications, and shapes with varied finishing. According to the current data, there are 3,500 different steel grades, and each type has unique properties. These different types of steel products are useful for other purposes. Each steel product shows a different chemical composition and manufacturing procedure. Pre-fabricated steel products are the significant difference between hot rolled steel and cold rolled steel.

Difference between hot rolled steel and cold rolled steel

Process of manufacturing is the main difference between hot rolled and cold rolled steel. Hot rolled steel are manufactured using a hot rolling process using heat. In contrast, cold rolled steel is the product that is produced using a cold rolling process performed at or near room temperature. Both of these techniques affect the overall performance and application of the product. Besides, the metallurgical composition and performance are different. Both of these products contain bare carbon steel and other alloy steels. After knowing the differences, one can save money and time as well. Several fundamental differences between these two types of hot rolled steel and cold rolled steel metals. These differences relate to the way these metals are processed, grade, and product specifications. For the production of Hot rolled steel, rolling of the steel is performed at high temperatures. In contrast, cold-rolled steel is produced using cold reduction mills, which involves consecutive cooling, annealing, and tempers rolling.

Hot rolled steel

Hot rolled steel undergoes a milling process that involves the rolling of the steel at a high temperature, typically over 1700° F. The temperature of rolling is above the steel’s recrystallization temperature. When steel is processed above the temperature of recrystallization, it can be shaped and formed easily. Further, hot rolled steel is available at cheaper rates than cold-rolled steel. Product is manufactured without delay in the process, which reduces its cost. Therefore, it eliminates the need for the reheating of the steel. After cooling, the steel shrinks slightly and gives less control of the finished product’s size and shape than cold-rolled steel products.
Processing at the higher temperature, i.e., over 1700˚F, makes the hot rolled steel form easily and produces easier work products. The manufacturing process of hot rolled steel involves the rectangular metal length, which is known as a billet. Heating of the billet is performed and then sent for pre-processing. During pre-processing, the material is flattened into a large roll. Then it is kept at a high temperature and passed through various rollers to reach its desired dimensions. Then at high temperature, white-hot strands of steel are pushed through the rollers. After performing these procedures, steel shrinks slightly with cooling. After cooling, these hot rolled steel prevents shaping and resizing as per desired applications. This hot rolled steel is useful in applications requiring slight differences in dimensions.

Uses of hot rolled steel

It is similar to hot rolled steel bars that are useful in welding and construction. Besides, hot rolled steel is helpful in conditions requiring precise shapes.

Cold-rolled steel

When hot rolled steel undergoes further procedures, then it forms cold-rolled steel. Here, in cold reduction mills, the steel is processed further. Also, in cold reduction mills, the material is cooled at room temperature, then undergo annealing and tempers rolling. These procedures result in closer dimensional tolerances and offer a good surface finish to cold rolled steel. Here, Cold Rolled is a term used for various products, where the product name denotes the rolling of flat-rolled sheet and coil products.

Cold rolled steel has the following advantages:

Cold rolled steel undergoes a process of cold drawing, which improves its yield strength and tensile strength. Also, it eliminates the need for further thermal procedures. Turning of steel removes surface imperfections. The process of grinding reduces the original size tolerance. The process of polishing improves surface finish. Cold product steel products offer superior surface finish and excellent tolerance capacity, and straightness compared to hot rolled steel products. Cold-rolled steel is more challenging to work with than hot rolled steel due to its high carbon content.

Uses of cold-rolled steel

These products are useful in any project requiring tolerances, surface condition, concentricity, and straightness.

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