The purpose of the calcium treatment is to effectively modify the inclusions in order to produce cleaner steel and avoid clogging. It reduces the spinels (MgO) into aluminates (Al2O3) and further transforms the aluminates to low-melting-point inclusions (below molten steel temperature). The liquid inclusions are easier to float to the surface than solid alumina inclusions.
Enough Calcium has to be added, with good calcium distribution in the melt, to avoid that high-melting-point calcium aluminate inclusions remain in the steel. If this quantity is insufficient, the aluminate inclusions will remain solid and subsequently affect casting and rolling performance as well as the steel properties. The Ca shall be added progressively to reach a ratio 12 CaO - 7 Al2O3 for inclusions with melting point of ca. 1400 °C.
We offer two ranges of high performance wires pure Calcium cored wires:
Three major factors of the product design strongly affect the metallurgical performance of Calcium wires:
· The thick sheath allows injecting the wire deep enough into the ladle where sufficient ferrostatic pressure is generated by the steel column to keep the Calcium liquid at steel making temperatures. When the Ca is liquid, it reacts much more efficiently with the inclusions. Such wires have a significantly better metallurgical performance than conventional CaFe of CaSi cored wire with wall thickness 0.4 mm.
· The use of welded sheath. If the sheath is welded, the Calcium is hermetically encapsulated in the wire. The so sealed wire does not open in the molten steel before reaching the necessary depth with sufficient ferrostatic pressure to keep the Ca liquid. The losses due to evaporation of the Ca are therefore limited.
· The use of solid Calcium wires, instead of Ca powder. Ceteris paribus, the cored wires made with extruded Calcium rod demonstrate superior metallurgical performance against wires made with Calcium powder. This is due to the different melting thermodynamics of the Calcium in powder form and in solid form.
As a matter of fact, Max-Cal® is the only Calcium cored wire combining these three features. It is the Calcium cored wire with the highest metallurgical performance currently available on the market! Because of its low manufacturing cost and because much lower quantity of Calcium (2 to 4 times) is injected to achieve the same metallurgical results, it makes it possible to generate very significant cost savings on your Calcium treatment.
Fo-Cal® is produced with more classical, locked or folded sheath technology. Its advantages are the cost and, in option, the high purity of the Calcium used (>99%) with particularly low Mg content (ca. 0.03% against generally ca. 0.5%).
Advantages of using our high-performance Calcium wires:
· Extra-high yield and strong reduction of the injected quantity of Calcium per tonne for similar or better metallurgical results (2 to 4 times).
· Reduction of the Calcium treatment cost between 20% and 40%.
· Higher stability of the Ca results, much tighter Ca ppm normal distribution.
· Concentration of the aluminate inclusions in the liquid zone on the ternary diagrams.
· Lower or eliminated risk of clogging.
· Strong reduction of the handling of coils (3-4 times) and the necessary storage surface.
· Reduced splashing and fuming (-50% to -70% in some cases), possibly resulting in savings on filtering.
· No wire breakages: the mechanical stability is guaranteed by the sheath and the solid extruded Ca rod inside, unlike products made with powder where the mechanical stability is guaranteed only by the sheath.
· Reduced wire stiffness due to the annealing of the wire.
· Long shelf-life for Max-Cal®, practically unlimited if properly stored and used.
· Possibility to use only one product, replacing both CaSi and CaFe.
For more information and data sheets, you can contact us at firstname.lastname@example.org.