Hot-rolled steel and cold-rolled steel are common metal materials, and there are obvious differences in their production processes and performance characteristics. The following will introduce in detail why hot-rolled steel and cold-rolled steel need to be distinguished, and explain the differences between them.

1. Production process: Hot-rolled steel is made by heating the billet to a high-temperature state and then rolling it continuously. This process changes the shape and size of the steel and relieves internal stresses. In contrast, cold-rolled steel is made by rolling hot-rolled steel at room temperature, deforming it through pressure without changing its temperature. The manufacturing process of cold-rolled steel requires more processes and equipment, so the cost is relatively high.

2. Organizational structure and performance:
Due to different production processes, there are also differences in the organizational structure and properties of hot-rolled steel and cold-rolled steel. The grains of hot-rolled steel are larger and loosely arranged. It has high plasticity and toughness and is suitable for occasions that require higher strength and wear resistance. The grains of cold-rolled steel are finer and more closely arranged, with higher strength and hardness, and are suitable for applications that require higher precision and surface smoothness.

3. Surface quality:
Hot-rolled steel is prone to oxide scale and rust during the production process, so its surface quality is relatively poor. Since cold-rolled steel is produced at room temperature, it can avoid the generation of oxide scale and rust and has better surface quality. This makes cold-rolled steel widely used in industries that require excellent surface quality, such as automobile manufacturing and home appliance manufacturing.

4. Application fields:
Due to the differences in properties and surface quality of hot-rolled steel and cold-rolled steel, they have their advantages in different application fields. Hot-rolled steel is often used in building structures, pipelines, large machinery manufacturing, and other fields. Its high plasticity and toughness can meet the needs of complex stress environments. Cold-rolled steel is widely used in automobile manufacturing, electronic equipment, home appliances, aerospace, and other fields. Its high strength and surface quality can meet precision processing and high-demand product manufacturing.

Summarize:
There are obvious differences between hot-rolled steel and cold-rolled steel in the production process, organizational structure, performance characteristics, and application fields. Hot-rolled steel has higher plasticity and toughness and is suitable for situations that require higher strength and wear resistance; while cold-rolled steel has higher strength and hardness and is suitable for situations that require higher precision and surface smoothness. Understanding their differences helps to correctly select and apply these two materials to meet the needs of different fields.