Steel goods come in all shapes and sizes, with their byproducts utilized in various sectors. Some manufacturers treat steel for developing automotive parts, while others are tailor-made for prefabricated construction projects. While it’s more common to know where these products will end up, not a lot of people ask about the production process.
When people think of hard and durable materials like steel, they imagine it produced in slabs or square billets. Unfortunately, steel in this state cannot be used for more delicate designs when building cars, machinery, or precise steel structures. This is why semi-finished products need to undergo a rolling process to mold steel into the desired shape, resulting in the proper physical and mechanical properties.
An Overview on Metallurgy
Metallurgy begins with the process of mixing materials like iron and coke to develop more complex byproducts. By using conventional technology, these base materials are turned into steel and semi-furnished steel by putting them into high-powered blast furnaces. This results in slabs, square billets, and other general shapes. Although most global producers of steel sell their products in bulk in this form, there’s also another step of going through the hot-rolling process.
Steel is sent to hot-rolling mills where semi-furnished steel undergoes a plastic deformation process. This occurs by passing between two rolls to create initial shape changes. Afterwar, the materials are subjected to heating temperatures above the steel recrystallization temperature. This allows the steel to be deformed, similar to the dough rolling process.
With the metal facing temperature up to 1,100°С for molding, the byproduct usually rests after being cooled down to 900°С. The extreme shifts in temperature to produce flat- and long-rolled steel is why it’s called the hot-rolling process.
A Result of Heating and Deforming
The semi-furnished is treated in rolling mills that consist of several stands, which can reach up to 15 “quarto” stands. Each stand contains a pair of rollers to mold the metal into a desired shape and edgers to finalize the strip along the edges. The process can be summed up as follows:
- Feeding of steel slabs into reheating furnaces
- Reheating proper
- Feeding of steels slabs to mill stands
- Commencing of the rolling passes
- Leveling of the rolled steel with a leveler
- Cooling through cooling beds
- In-line non-destructive testing
- Finishing through trimming and cutting to length,
- Check testing, acceptance, and marking of steel byproducts
A Classification in Quality
After going through these steps above, the hot-rolled steel can turn into a wide range of products. Each shape and structure has a function in a specific industry. Listed below are some examples of flat- and long-rolled steel variants:
- Coils varying in thickness reaching up to 25 mm
- Plates varying in thickness from 4 to 350 mm
- Sheets varying in thickness from 1.2 to 4 mm
- Different sections of simple shapes (round, square, rebar, flat bar, wire rod)
- Different structural shapes (angles, H-beams, rails, channels, special profiles)
The produced steel products are classified in different grades, depending on their accuracy, flatness, and edge type. This added precision in the material’s manufactured properties makes the flat- and rolled- steel variants above apply to an even wider range of uses.
Through the hot-rolling process, the manufactured steel can cater to a wider range of practical uses. Additionally, financing for hot-rolled steel processes is much cheaper than cold-rolled steel, so it’s much easier to undergo this manufacturing model. For this reason, hot-rolling is the method of choice for large construction projects in the engineering industry.
At KGS Steel Inc., we’re well-versed in utilizing different manufacturing techniques to serve your material needs. If you’re looking for quality structural steel suppliers in Birmingham that provide hot rolled steel products, contact us today.