One of ArcelorMittal Vega's product lines is cold-rolled steel. At the end of the cold rolling, the steel is completely hardened, and the grains assume an elongated shape in the direction of the lamination. At this stage the mechanical properties of the material are profoundly changed, experiencing a drop in ductility and an increase in mechanical resistance.
In these circumstances an annealing process is necessary so that the mechanical properties are recuperated. After annealing, the hardening process is carried out. It consists of giving the sheet a slight elongation (from 0.3 to 2% generally) by a combination of compression and traction stress. This occurs by passing the steel sheet coil through the hardening laminator (Skin Pass), with controlled speed and pressure.