Structural metal profile
Structural metal profile come in a variety of shapes and configurations, and they are categorized by groups within sections, from small to large. They may be in the form of angle, channel, I and wide-flange beams, square and rectangular tubing, solid bars, flat stock, railroad rails, and T’s, metal profile fall into two primary types:
Load-bearing and Architectural
In both cases, product quality is critical. Bend and material integrity is the principal consideration for load-bearing structurals, and physical appearance is most important for architectural shapes.
A typical load-bearing metal profile application is wide-flange beams used in road overpasses, whereas shaped profiles often are found in buildings and entrances to recreational areas and amusement parks and in sculptures.
For structural metal profile—angle, channel, T’s, beams, and rails—the challenge begins with tight radii. When a radius is tight, the material tends to deform easily, eventually reaching a point at which further deforming will destroy it.
There are many processes to bend metal profiles, and cold bending is one of the commonly used methods; profile bending machine and plate bending machines are machines that use the principle of three points to make a circle and use cold bending to bend metal profiles.
Cold bending process
The so-called cold bending refers to the distinction between the processing process and the hot bending process. In the hot bending process, the metal profiles is heated by a torch or furnace before forming.
This process is generally performed using rollers to press a piece of steel against metal shaping tools called dies. It may also be referred to as cold rolling or pyramid rolling.
Benefits of cold bending
Cold bending does not require the use of fuel to heat the metal profile before processing, and eliminates the extra time and effort of heating and then cooling the metal profile.
Cold rolling can produce a smoother, smoother surface and generally results in less deformation of the processed article.
Increase the strength of metal profile
Another advantage is that processing the metal profile in the cold state can increase the strength.
When the metal profile is manufactured at high temperature and then cooled, an internal crystal arrangement is formed.
Studies have shown that at ambient temperatures below the crystallization point, working metal profiles will compress and distort the crystal structure to increase the strength at the molecular level.
As the molecules are compressed, they will not be able to move easily, so the metal profile becomes stronger.
Cold Bending VS Hot Bneding
A metal profile that works at a high temperature above the crystallization point means that crystallization will occur after the metal profile is processed, so the metal profile will not be stronger than the unprocessed metal profile.
Heated metal profiles that have been cold-formed or rolled will restore the material to its internal crystal structure, thereby causing the material to lose the extra strength gained from the process.
The trade-off between cold working and hot working is that in exchange for the added strength of cold working, metal profiles may become more brittle, while hot-worked metal profiles generally maintain greater ductility.
Cold bending of different metal profiles
As long as it can fit the existing molds and rolls, metal profiles of any cross-section and size can be cold-formed or rolled.
Cold bending is most commonly used for pipes, channels, I-beams, H-beams, angles, and rectangular, round and semi-circular bars or tubes with a diameter of less than 20 inches.
Reading More: Profile Bending
It is also possible to process large steel products such as steel plates, but the size is limited due to the required force and the size of the required rolling equipment.
The bending process can be used to create gentle large-diameter curves, 90° angles or long series of coils, in which the tube is bent in a continuous 360° circle.
For cold-formed metal profiles
Cold-formed metal profiles have many uses. Bent metal profiles formed by cold bending are often used in the structure of buildings and bridges, and are especially impressive when exposed to view.
Shipyards, railway and automobile manufacturers also use cold-formed metal profile products. The petrochemical industry uses bent and coiled pipes to process and transport its products. Cold-formed metal profiles also have many other industrial and food processing applications.
Cold bending is an excellent method for forming metal profiles with minimal deformation during the bending process.
The application range of cold-formed metal profiles is very wide, from daily necessities for daily use to highly specialized industrial applications.