I-beams, also known as H-beams or universal beams, are formed through a combination of casting, rolling, and shaping processes. Here’s how they are typically made:
- Raw Material (Steel) Preparation:
The process starts with the raw material, usually steel billets, ingots, or scrap steel, which is melted in a furnace.
- Casting:
The molten steel is poured into molds to form long slabs, blooms, or billets, depending on the beam size and specifications. These solidified steel pieces are called cast slabs or blooms.
3. Hot Rolling.
These steel slabs or blooms are heated to very high temperatures (around 1,200°C) to soften the material for shaping.
They are then passed through a series of rollers in a rolling mill, which gradually shape the steel into the I or H profile. During this process, the cross-section of the beam is refined into the desired dimensions.
- Shaping and Finishing:
The steel is shaped into the I-beam profile, with the flanges (the top and bottom horizontal parts) and the web (the vertical part) forming the characteristic I-shape.
Depending on the required specifications, the beam may go through additional steps like straightening, cutting to size, and sometimes additional heat treatments to achieve specific mechanical properties.
5. Quality Control.
The beams are inspected for dimensional accuracy, strength, and any defects like cracks or inclusions. Some beams may also be tested for hardness or undergo ultrasonic inspection for internal defects.
- Cooling and Finishing:
After rolling, the beams are cooled in a controlled manner, usually on a cooling bed, to allow the material to normalize and achieve its final properties.
Finally, they are cut to length, sometimes surface treated (e.g., galvanized or painted), and prepared for transport or further fabrication.
This process ensures that the I-beams have a strong structure with good resistance to bending, making them ideal for construction and structural applications.