Steel wire rod production
Steel wire is produced on small-section rolling mills by rolling (⌀ > 5 mm) or by drawing through wire dies (⌀ < 5 mm). A 10×10 mm square bar is used as the billet, which is compressed between sequentially arranged rolls, giving the rolled product a circular cross-section of the specified thickness. After rolling, the finished product is fed to a mechanism that coils the continuous product into a coil weighing 1200–1450 kg.
Once the round steel has been coiled, it is cooled. Three cooling methods are used for this purpose:
- accelerated in a single stage (in chambers with powerful extraction);
- accelerated in two stages (in chambers with powerful extraction);
- natural (outdoors at temperatures up to 10 °C).
Rapidly cooled wire rod is produced in a hardened or semi-hardened state, whilst naturally cooled rolled stock is strong and flexible.
Each coil is tied at four points around its circumference using 6.5–7.0 mm knitting yarn to prevent the coil from unravelling during transport. A tag is attached at the start and end of the coil, bearing the following information:
- manufacturing plant;
- marking of rolled metal;
- melt and team number;
- spinning wheel;
- Q&A label.