Calcium-silicon cored wire is a functional metallurgical auxiliary material with a core structure of "calcium-silicon alloy powder encapsulated in low-carbon steel strip", formed into continuous wires with a diameter of 10-13mm through cold rolling. Its core components typically include silicon (Si: 55-60%), calcium (Ca: 28-30%), with strict control over impurity contents such as phosphorus (P) and sulfur (S). By using a dedicated wire feeder to accurately deliver the alloy powder into the molten steel, it leverages the synergistic metallurgical effects of silicon and calcium to achieve deoxidation, desulfurization, inclusion spheroidization, and grain refinement of molten steel. Ultimately, it improves the purity, toughness, and processing performance of steel, serving as a key material for high-quality steel production.
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Aspect |
Description |
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Core Structure |
Sheath: Cold-rolled low-carbon steel strip (approx. 0.2-0.6mm thick); Core: Silicon-calcium alloy powder |
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Appearance |
Cable-like, typically wound into coils, common outer diameter: 13 mm |
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Primary Function |
Deep deoxidation and desulfurization of molten steel, modification of harmful inclusions |
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Key Advantages |
High and stable alloy yield, precise composition control, safe and easily automated operation |
Working Principle and Value
Calcium-silicon cored wire is applied using a specialized wire feeder. The feeder draws the cored wire from the reel, passes it through a guide tube at a precisely controlled speed, and injects it into the molten steel deep inside the ladle.
Upon entering the molten steel, the outer steel strip of the cored wire melts rapidly, exposing the internal calcium-silicon alloy powder to the high-temperature molten steel. Silicon and calcium are chemically highly reactive elements, which effectively perform the following key functions:
Deoxidation and Desulfurization
They react with oxygen and sulfur in the molten steel to achieve deep deoxidation and desulfurization, thereby purifying the molten steel.
Inclusion Modification
his is one of the core functions of calcium treatment. It transforms high-melting-point, hard inclusions like alumina in the steel into low-melting-point, spherical calcium aluminate inclusions. This modified form of inclusion does not elongate during rolling, greatly improving the steel's plasticity, impact toughness, and fatigue life.
Prevention of Nozzle Clogging
During continuous casting, the modified inclusions are less likely to accumulate at the tundish nozzle, effectively preventing nozzle clogging and ensuring smooth production.
Common Specifications and Types
Calcium-silicon cored wire features standard chemical composition and physical specifications. For example, a common type of calcium-silicon cored wire has the following chemical composition requirements for its core powder: calcium content not less than 28%, and silicon content between 55% and 65%. Products are usually available in a variety of wire diameters, such as 9mm, 13mm, 16mm, etc., to meet the requirements of different ladle capacities and process needs.
Besides standard silicon-calcium cored wire, there are various other types for different refining purposes, such as pure calcium wire, ferro-titanium cored wire, carbon wire, etc., forming a large family of cored wires.
In summary, calcium-silicon cored wire is a very mature and efficient secondary refining technology, and an indispensable important auxiliary material for modern iron and steel enterprises to produce high-quality steel.
