Hot rolled steel and cold rolled steel are two types of steel that differ in the way they are processed or manufactured.
The best type of steel for a particular application depends on the specific requirements of that application. If strength and ductility are the most important factors, then hot rolled steel is the better choice. If strength, hardness, and surface finish are the most important factors, then cold rolled steel is the better choice.
In general, hot rolled steel is less expensive than cold rolled steel. However, the cost difference between the two types of steel is relatively small.
Hot rolled steel #
Hot-rolled steel is a type of steel that is produced at high temperatures. During hot rolling, molten steel is pressed at extremely high temperatures, typically reaching or exceeding 1400 °C. This is important because steel recrystallizes at roughly between 400 and 700 °C, which allows it to be reshaped. Once the hot-rolled steel has cooled, it is ready for use or sale.
Hot rolled steel is produced by rolling steel slabs at high temperatures, typically above 1000 °C. This process makes the steel more ductile and malleable, but it also produces a rougher surface finish.
Hot rolled steel is commonly used in applications where strength and ductility are more important than surface finish. Some examples of applications for hot rolled steel include:
- Structural beams
- Railroad tracks
- Automotive frames
- Oil and gas pipelines
- Shipbuilding
Cold rolled steel #
Cold-rolled steel is produced by rolling hot-rolled steel at room temperature. This process increases the strength and hardness of the steel, but it also makes it less ductile. Cold-rolled steel is often used for applications where strength and hardness are more important than ductility, such as car bodies and appliances. Cold rolled steel also has a smoother surface finish when compared to hot rolled steel.
Cold rolled steel is commonly used in applications where strength, hardness, and surface finish are important. Some examples of applications for cold rolled steel include:
- Automotive body panels
- Appliances
- Electrical enclosures
- Furniture
- Food processing equipment
Comparison Cold vs Hot rolled steel #
Here is a table comparing properties hot rolled steel and cold rolled steel:
| Property | Hot rolled steel | Cold rolled steel |
|---|---|---|
| Strength | Low | High |
| Hardness | Low | High |
| Ductility | High | Low |
| Malleability | High | Low |
| Surface finish | Rough | Smooth |
| Cost | Low | High |
