Rolling is promotes grain orientation and strength in all steel products. Quality rolled steel sheets are necessary in accomplishing different applications and fabrication techniques.
This key element in metal manufacturing occurs in one of two ways: hot or cold. Hot and cold rolling relate to metal’s grade or specification. It also refers to how steel sheet manufacturers process the material at the mill.
As implied by the name, these different processes depend on the metal’s temperature. But apart from “hot” and “cold,” what factors set these methods apart? Which one is ideal for your project?
Cold Rolled: The Basic Shapes
Suppliers perform cold rolling at room temperature. The material undergoes further processing in comparison to its counterpart. The process also shapes steel in basic forms such as squares, tubes, and sheets—minus the heat. This ensures the material retains its level of resilience and durability.
The process annealing or softening steel involves heating the metal and allowing it to cool slowly to reduce stress. After rolling, manufacturers leave the steel to cool in reduction mills. Its ductility makes shape-forming difficult, which is why only basic shapes are possible. Cold-rolled steel is ideal for applications that require minimal mechanical fluctuation.
Hot Rolled: Melting Points
The hot rolling process heats the steel just beneath the melting point. The extreme temperatures (typically stands at about 1700° Fahrenheit up to 2,100 degrees Fahrenheit) configure the steel’s crystalline structure, resulting in a softer and more malleable material. Temperatures should exceed these levels for an easier shaping and forming process.
Also, the steel’s rough and blue-gray finish is due to the heating process. Due to the long waiting period and extreme temperatures, the metal takes a longer time to oxidize. This produces a tough oxide exterior with a blue-gray finish.
Hot-rolled steel is ideal for industrial applications such as sheet metal, structural beams, and rail tracks. It is also the preferred process for larger steel shapes.
Choosing the right steel sheet ensures you meet project requirements on quality and durability. From cold-rolled to hot-rolled, make sure to source your steel sheets from reliable suppliers.