Calcium Silicon alloy cored wire remains one of the most widely adopted calcium treatment materials for secondary steel refining and modern foundry operations worldwide.
For decades, steel plants and casting manufacturers have tried bulk silicon calcium lumps and pneumatic powder injection to conduct deoxidation and desulfurization. However, these methods suffer from severe calcium oxidation, low element recovery, unstable molten steel quality and heavy dust pollution.
Manufactured by wrapping silicon calcium alloy powder inside continuous low-carbon steel strip, CaSi cored wire can be fed deep into molten metal with automatic wire feeders. The steel shell delays powder exposure to air and slag, cutting burning loss significantly.
Basic Structure & Commercial Grades of Silicon Calcium Cored Wire
A complete Silicon Calcium CW consists of two core components: low-carbon steel outer sheath and graded silicon calcium alloy filling powder.
Uniform particle distribution of inner powder and consistent filling weight directly decide stable wire feeding performance and final metallurgical results. The table below lists mainstream specifications commonly traded in international metallurgy markets.
| Grade of Core Powder | Outer Diameter | Filling Weight (g/m) | Key Features |
|---|---|---|---|
| Si60Ca28 | 13mm /16mm | 220 – 240 | Cost competitive; meets general deoxidation and desulfurization requirements |
| Si60Ca30 | 13mm | 230 – 250 | Higher calcium content; excellent for inclusion modification in continuous casting |
| Si62Ca32 Low-impurity Grade | 16mm | 240 – 260 | Strict control on P, S and Al impurities; designed for clean steel production |
Field observation: When adding loose silicon calcium blocks in open ladles, calcium recovery usually stays between 6% –14%. Using qualified silicon calcium cored wire can lift recovery to 18% –26%, which lowers overall ferroalloy consumption over long-term production.
Core Functions in Steel Refining and Casting
Deep Deoxidation and Desulfurization
Once delivered into the lower layer of molten steel, the steel casing melts gradually. Active silicon and calcium are released continuously.
Silicon removes dissolved oxygen inside molten steel, while calcium reacts with sulfur to form stable calcium sulfide. This process reduces total oxygen and sulfur levels and improves molten steel cleanliness.
Modify Solid Inclusions to Avoid Continuous Casting Nozzle Blockage
Hard alumina inclusions are the primary cause of nozzle clogging during continuous casting.
Calcium from silicon calcium cored wire turns sharp solid alumina particles into low-melting spherical calcium aluminate. Spherical inclusions float out more easily and will not accumulate on inner walls of nozzles, stabilizing casting rhythm and reducing unexpected line shutdowns.
Improve Mechanical Properties of Finished Metal
Calcium treatment helps reduce sulfide segregation inside steel matrix. For ductile iron production, auxiliary feeding of silicon calcium cored wire refines graphite shape, lowers chill tendency of castings, and minimizes shrinkage porosity defects on thick-section workpieces.
Realize Quantitative and Automated Alloy Addition
Manual alloy feeding leads to random dosage fluctuation. Automatic wire feeding offers steady, fixed-rate addition. Steel workshops can adjust feeding speed and total length according to ladle capacity, making molten steel composition more consistent between different batches.
Practical Application for Different Production Lines
LF Ladle Refining & Conventional Continuous Casting Steel
Recommended grade: Si60Ca30 silicon calcium cored wire
Carbon structural steel, steel plate and strip steel production require regular calcium treatment after LF refining. Proper cored wire addition controls inclusion morphology and guarantees smooth continuous casting. Many medium-sized steel mills choose this grade to balance performance and raw material expenditure.
High-grade Clean Steel, Pipeline Steel and Automotive Steel
Recommended grade: Low-impurity Si62Ca32 cored wire
Products such as oil pipeline steel, pressure vessel steel and automotive structural steel demand extremely low trace impurities. High-purity silicon calcium powder with limited phosphorus and sulfur prevents impurity contamination. The finished steel obtains better welding performance and impact toughness.
Ductile Iron and General Gray Iron Foundry
Recommended grade: Si60Ca28 silicon calcium cored wire
Foundries use silicon calcium wire as supplementary inoculant inside the ladle. It optimizes graphite spheroidization rate for ductile iron castings. For mass production of ordinary mechanical castings, this standard grade delivers reliable results without excessive production costs.
Quick Selection Reference Table
| Production Line | Suggested Cored Wire Grade | Main Target | Typical End Products |
|---|---|---|---|
| Ordinary carbon steel refining | Si60Ca28 | Basic deoxidation & desulfurization | Common structural steel, round bars |
| Continuous casting steel production | Si60Ca30 | Inclusion modification, prevent nozzle clogging | Steel sheet, section steel |
| Clean steel & pipeline steel | Si62Ca32 low-impurity type | Deep molten steel purification | Pipeline steel, vehicle steel parts |
| Ductile iron casting workshop | Si60Ca28 | Graphite refinement, reduce casting defects | Pump parts, automotive ductile iron components |
Frequent On-site Problems & Solutions
Wire breaking during feeding: Mostly caused by uneven powder size or insufficient thickness of the steel strip. Ask suppliers to control oversize particles and inspect tensile strength before shipment.
Unstable calcium recovery: Avoid feeding cored wire too close to slag surface. Operators should adjust wire insertion depth and feeding speed based on actual ladle conditions.
Powder leakage during transportation: Damaged outer wrapping causes leakage. Goods should adopt plastic inner liner plus woven bag packaging. Keep pallets dry during ocean shipping.
No obvious improvement on casting defects: Check whether the feeding timing matches ladle treatment process. Late inoculation effect will weaken if added too early.
Silicon calcium alloy cored wire remains an economical choice for calcium treatment in steel refining and high-quality casting. Compared with traditional alloy feeding methods, it brings higher element recovery, easier automation and fewer production defects.
Select Si60Ca28 for general steelmaking and regular ductile iron production. Si60Ca30 fits most continuous casting workshops aiming to solve nozzle clogging issues. Manufacturers producing premium clean steel can invest in low-impurity Si62Ca32 cored wire.
When communicating with suppliers, share detailed information including ladle volume, target steel grade, wire feeder parameters and quality standards. Matching the correct specification to your production process delivers the best long-term economic benefits.
