Billets

The main source of feedstock is Hot Briquetted Iron (HBI) in briquette form. The use of this material allows the manufacture of a steel with low residuals and low nitrogen content, which confers excellent mechanical properties to the final rolled product. The HBI used, contains a percentage of metallic, minimum of 85%, comprising a load pattern that varies from 70% to 100% reduced iron, according to the requirements for the steel. The rest of the load is complemented with classified scrap, which was controlled against radioactivity.

The melt shop consists of an electric arc furnace of, nominal capacity 75 t, with eccentric tap and water-cooled walls of the upper part of the shell, the transformer rating is 70 MVA. The use of eccentric tap technology in the bottom, avoids re-oxidation of the liquid steel and defines the quality of SIDETUR’s steel when producing slag free taps.
The ladle furnace has a nominal capacity of 75 t, an automated additive load system and agitation with inert gas. The advantages of the processing in ladle furnace include:

• Improvement of the de-oxidation process.
• Allows the de-sulphuration of the steel.
• Better gas control –in the steel (N₂ and H₂).
• Allows modification of inclusions.
• Improves the chemistry range fulfillment.
  

The Continuous Casting Machine is equipped with four production lines with capacity to install a fifth line. Its radius of curvature is 6 Mts. (20'-0"), casting speed up to 5 m/min. (16.4ft. /min.), system of cut with oxi-torch, revolving Ladle Turret with scale for weight control, curved and conical copper molds of 800 mm in length, system of electromagnetic stirring in molds, automated system of secondary cooling, length of cut of 2,8 mts. to 14 mts. and shrouding system from ladle to tundish with ceramic tube and from tundish to mold.

These technical features allow:

• Sequential taps by means of the ladle turret.
• Low level of inclusions, avoiding the reoxidation and remarkably improving the superficial and internal quality of the steel using bellow shrouding.
• Reduction of segregation effects and consequently a uniform distribution of the elements by the use of the electromagnetic agitation, which improves the properties of plastic deformation in the process of transformation of the billet.
• Possibility of making aluminum killed Steel