Cold Rolling
As one of the oldest metalworking processes, cold rolling has been around since the mid-1700’s. Cold rolling is a process used to shape metals and alloy by introducing them to rolling mills at room temperature, in contrast to hot rolling which involves heating the material before rolling. It is a common practice in the modern age, used extensively in producing large sheets, strips, and tubes from hot rolled coils of metal.
The cold rolling process begins by the hot rolling coils being fed into a cold rolling mill, a process which happens at room temperature. The metal is passed between a series of heavy rolls which shape, flatten and compress the metal, using a high pressure to make sheets, strips, and tubes as desired.
Cold rolling is able to produce materials with high strength, low-cost, small in size and preferable in shape, thanks to the large amount of strain that it can put on the metal. It is widely used in the production of car body parts, food cans, and is also used in the production of turbines and high precision parts.
The process of cold rolling has several advantages over other metalworking processes like hot rolling. Cold rolled materials display better formability since the process of reducing the material’s thickness and work hardening has already occurred during the cold rolling process. Cold rolled materials also are better for deforming components because materials can be reduced more in thickness than with hot-rolling, which allows for more accurate geometries to be achieved. Finally, the surface finishing capabilities of the cold rolling process is beneficial as the material is already highly compressed in it’s texture and this reduces the chances of breaking up materials when machining and finishing down their edges.
Despite its advantages, cold rolling and the other metalworking processes that depend on it also present a wide range of challenges and potential problems. One of the biggest challenges that many companies face is controlling the strip thickness and shape in the cold rolling process.The complex tooling provides a challenge when scales form on the strip surface, as they can cause difficulties in using the machinery.
Other challenges include when cracks form on the outside of the strip in comparison to where the strip is thinner on the inside and as a result the metal needs to be melted again in order to be cold rolled. In addition, surfaces produced by cold rolling may have irregular grain structures, so to ensure the final product meets required standards, the temperatures and speeds need to be closely monitored and even the lubricant use is essential.
Overall, cold rolling is a metalworking technique that remains popular due to the many benefits it presents to companies looking for metalworking solutions. The process offers a high strength product with a low cost, along with a range of other advantages, however it remains important for companies to be aware of the potential challenges that can occur during the rolling process.
