Steel wire rods are primarily manufactured through a hot rolling process that transforms larger steel sections into thinner rods.
The production of steel wire rod begins with semi-finished steel products known as blooms or billets. These are essentially larger, solid steel sections produced earlier in the steelmaking process.
These blooms or billets are first heated to high temperatures, making the steel malleable enough to be shaped. Following heating, the material undergoes a hot roll process, where blooms or billets are heated and then rolled to the required diameter through a series of rolling passes.
This series of rolling passes gradually reduces the cross-sectional area of the steel while increasing its length. These passes are typically divided into distinct stages:
- Roughing Passes: The initial stages where the bloom or billet is significantly reduced in size and shaped closer to a round form.
- Intermediate Passes: Further reduction and shaping occur in these middle stages.
- Finishing Passes: The final stages where the rod is rolled to its precise required diameter and tolerance.
Each rolling pass uses grooved rolls that progressively squeeze and shape the steel. The hot rolling ensures the steel remains pliable throughout the process.
Here's a simplified look at the process stages:
| Stage | Description | Output Form (Simplified) |
|---|---|---|
| Input Material | Blooms or Billets | Large Square/Rectangular |
| Heating | Material heated to rolling temperature | N/A |
| Rolling | Series of rolling passes (Roughing, Intermediate, Finishing) | Gradually smaller round |
| Output | Finished Steel Wire Rod | Small Round Rod |
After the final rolling pass, the wire rod is typically cooled, often in a controlled manner to achieve desired metallurgical properties, and then coiled for transportation or further processing into wire.
