How Is Hot-Rolled Steel Made?

Hot-rolled steel products contain hot-rolled steel coils and hot-rolled steel sheets. At Wanzhi Steel, hot-rolled steel products are hot selling. Hot-rolled steel is mainly used to produce sheet metal parts or products with simple profiles, such as rail tracks. Understanding how hot-rolled steel is made can help you better buy high-quality hot-rolled steel products. Follow us to get more information!

How Is Hot-rolled Steel Made?

Hot rolling is a rolling process that is carried out above the recrystallization temperature of steel, and the rolling process is a pressure processing process that changes the shape of the billet between rotating rolls. During hot rolling, the metal has high plasticity and low deformation resistance, which greatly reduces the energy consumption of metal deformation. Therefore, hot rolling can significantly reduce energy consumption and reduce costs. In addition, hot rolling can improve the processing properties of metals and alloys, that is, the coarse grains in the casting state are broken, the cracks are significantly healed, the casting defects are reduced or eliminated, the as-cast structure is transformed into deformed structure, and the processing properties of the alloy are improved. Hot rolling usually adopts large ingot and large reduction rolling, which not only improves production efficiency but also creates conditions for improving the rolling speed, realizing the continuity and automation of the rolling process. Generally, hot rolled strip with a thickness of 1.2~8mm can be produced on a hot strip mill. The hot rolling process is generally the continuous casting of steel plate blank into the heating furnace heating to a certain temperature, through the conveyor table to the mill for rolling into strip steel, steel, or steel pipe. The strip also needs to be rolled into coils by a coiler for transport.

Hot-rolled Steel vs. Cold-rolled Steel

Cold rolling is to use hot rolled steel coil as raw material, after pickling to remove the oxide. Cold rolling usually adopts longitudinal rolling (a rolling method in which the roll axis is parallel, the rotation direction is opposite, and the rolled piece moves in a straight line). The processes of cold rolling production generally include uncoiling, rolling, degreasing (pickling), annealing (heat treatment), coiling, etc., and the production of automotive plates also requires galvanizing and other processes.

The difference between Hot-rolled And Cold-rolled

1. Production temperature: Hot-rolled steel sheets are produced at high temperatures, usually at a temperature of more than 1000 degrees Celsius; Cold-rolled steel is produced at room temperature.

2. Surface finish: Because the hot-rolled steel plate is produced at high temperature, the surface is rough and has defects such as oxide skin; The surface of the cold-rolled steel plate is relatively smooth, without defects such as oxide skin.

3. Mechanical properties: Due to different production processes, the mechanical properties of hot-rolled steel plates and cold-rolled steel plates are also different. Generally speaking, the strength and toughness of hot-rolled steel plates are high, but the plasticity is poor; The cold-rolled steel plate has better plasticity, but the strength and toughness are relatively low.

4. Different uses: Due to differences in mechanical properties and surface finish, hot-rolled steel plates and cold-rolled steel plates are also different in the use of occasions. Hot-rolled steel sheets are usually used in heavy-duty structures, pressure vessels, and other fields; The cold-rolled steel plate is suitable for automobiles, home appliances, construction, and other fields.

Why The Price Of Cold-rolled Steel And Hot-rolled Steel Is Different?

1. Production cost

Cold-rolled steel has a higher production cost than hot-rolled steel. Cold-rolled steel is rolled at room temperature, so it requires higher processing difficulty and strict processing technology. In addition, cold rolling does not require heat treatment, so high-tech production equipment is required, resulting in an increase in the production cost of cold-rolled steel.

2. Market demand

From the market demand point of view, cold rolled steel due to the complex production process, the market supply is small, and the demand is high, so the price is more expensive. However, hot-rolled steel is rolled by heating billets to high temperatures. The production process of hot-rolled steel is simple, and it is a type of steel that is mass-produced and applied. As the market competition is more intense, the price is relatively low.

3. Material specifications

For the same material specifications, the price of cold-rolled steel is generally higher than that of hot-rolled steel. On the one hand, it is related to production costs, and on the other hand, it is because cold-rolled steel has better physical properties in use, so the price is higher.

Conclusion

Hot-rolled steel has plasticity, good weldability, easy processing, good weldability, and other properties, so it is widely used in automobiles, bridges, construction, machinery, and other manufacturing industries. If you need to buy hot-rolled steel, please feel free to contact us. We have a professional hot rolling production line, you can visit our factory, visit our hot rolling production line. We have professional business staff at your service 24 hours a day, any questions about hot rolled steel, do not hesitate to contact us at any time.