After tapping of steel from a primary steelmaking furnace such as BOF, EAF or EOF, molten steel for high quality or specialty applications is subject of further refining in a number of processes known as ladle metallurgy, sometimes also called ladle refining, secondary steelmaking or secondary metallurgy.
The additives for this refining can be added as bulk, but introducing metals and alloys in this way into the melt is sometimes problematic. Since the 1980s, the use of cored wires became widely spread as it offers numerous advantages: precise additions, much better levels of recovery and reproducibility.
The cored wire is manufactured by encapsulating powders in steel sheaths, the wires is coiled. Wire diameters range from 5 to 18 mm, their injection is carried out using with specially designed wire feeders.
Treatments with cored wires have different objectives:
The sheath thickness of conventional cored wires is generally 0.4 mm. For high performance pure Calcium wire, the sheath thickness can range from 0.6 to 1.5 mm.
Different technologies are used for the production of cored wires, the most common being the folded sheath.
For some wires, including our Max-Cal®, welding technology is used. The wires with welded sheath have significantly higher performance against all other Ca-containing wires.