CaSi (Calcium Silicon) cored wire is an essential fine-adjustment metallurgical material in modern secondary steelmaking. It delivers precise calcium and silicon supplementation, modifies oxide and sulfide inclusions, improves steel castability, and enhances final mechanical performance. Unlike conventional bulk alloys, cored wire features stable feeding, high element recovery rate, and minimal burning loss. However, mismatched CaSi wire specifications for different steel grades will cause unstable inclusion control, poor surface quality, and increased production costs.
Core Functions of Calcium Silicon Cored Wire in Steelmaking
Before selection, it is critical to understand the core metallurgical purposes of CaSi CW, which determine your specification requirements:
- Inclusion Modification: Converts hard, irregular alumina inclusions into soft, spherical calcium aluminate inclusions, effectively reducing nozzle clogging during continuous casting.
- Desulfurization & Deoxidation: Removes residual oxygen and sulfur in molten steel, improving steel purity and homogeneity.
- Mechanical Property Optimization: Refines grain structure, improves steel toughness, fatigue resistance, and impact performance, especially for low-alloy and high-strength steel.
- Stable Alloy Recovery: Closed wire feeding reduces element volatilization, ensuring consistent Ca and Si content batch by batch.
Key Selection Parameters for CaSi Cored Wire
Professional steel mills judge wire suitability based on three core parameters, which apply to all steel grade production scenarios:
Chemical Composition Ratio
Common commercial grades include standard Ca28Si60, Ca30Si60, and high-calcium customized grades. Higher calcium content offers stronger inclusion modification and desulfurization capacity, while silicon content ensures stable deoxidation efficiency.
Wire Diameter & Filling Rate
Regular sizes are 9mm and 13mm. Fine wire (9mm) suits precise fine-tuning and low-dose feeding; thick wire (13mm) fits large ladles and high-yield continuous casting lines with higher single-meter filling volume.
Sheath Material & Sealing Quality
Low-carbon steel sheath with tight welding prevents powder leakage and moisture absorption, ensuring stable feeding speed and consistent metallurgical effects throughout production.
Grade-Specific CaSi Cored Wire Selection Guide
This is the most practical reference for foreign steelmakers. Different steel types require targeted CaSi wire specifications to balance quality stability and production cost.
Ordinary Carbon Steel & Construction Steel
Recommended Grade: Ca28Si60, 13mm standard wire
For Q235, Q355 and common structural steel, conventional deoxidation and inclusion control are sufficient. Standard Ca28Si60 wire provides stable desulfurization and low-cost inclusion modification. It effectively reduces casting defects and meets mass production requirements with excellent cost performance.
Low-Alloy High-Strength Steel & Pipeline Steel
Recommended Grade: Ca30Si60 high-calcium wire
Pipeline steel and high-strength structural steel demand ultra-clean molten steel and uniform internal structure. High-calcium CaSi wire deeply modifies alumina inclusions, avoids nozzle clogging in high-speed continuous casting, and significantly improves steel toughness and weldability.
Spring Steel & Tool Steel
Recommended Grade: Low-impurity Ca30Si60 wire
Spring steel and tool steel are extremely sensitive to inclusions and residual impurities. Low-sulfur, low-phosphorus high-purity CaSi cored wire is required to avoid brittle inclusions, stabilize elastic limit and hardness consistency, and extend finished product fatigue life.
Electrical Steel & Ultra-Low Carbon Steel
Recommended Grade: Custom high-Ca low-Si wire
Ultra-low carbon steel and electrical steel have strict limits on silicon residuals. Adopt high-calcium and low-silicon customized CaSi wire to achieve calcium modification without exceeding the steel's silicon specification, ensuring magnetic conductivity and material purity.
Ductile Iron & High-Grade Castings
Recommended Grade: Standard Ca28Si60, 9mm fine wire
Fine-size cored wire ensures uniform molten iron nucleation, refines graphite structure, improves casting fluidity, and effectively eliminates shrinkage porosity and cold shut defects for precision castings.
Professional Usage & Purchasing Tips
- Match Feeding Speed: Control feeding speed at 15–25 m/min according to ladle capacity to ensure calcium melts fully and avoids floating loss.
- Strict Impurity Control: High-end steel production requires low S/P CaSi alloy wire to prevent secondary pollution of molten steel.
- Batch Consistency Check: Verify CoA reports for each batch to ensure stable Ca/Si ratio and filling density.
- Dry Storage: Keep cored wire sealed and dry to prevent moisture-induced feeding jamming and molten steel splashing.
Selecting the correct Calcium Silicon CW for different steel grades is the key to stabilizing steel purity, improving casting performance, and optimizing production costs. Ordinary carbon steel adapts standard Ca28Si60 for cost efficiency; high-strength and pipeline steel require high-calcium Ca30Si60 for deep inclusion modification; ultra-low carbon and electrical steel need customized low-residual specifications. By matching wire composition, diameter and feeding parameters to specific steel grades, steel mills can achieve stable metallurgical effects, reduce defective rates, and maximize production benefits.
