Silicon Calcium 55-28 – Dual-Alloy for Steel Refining & Nodulizer (Si≥55% / Ca≥28%)
High-performance calcium silicon alloy with minimum 55% silicon and 28% calcium. Essential for inclusion control, deoxidation, and producing nodular cast iron.
| Main Composition | Si ≥55.0%, Ca ≥28.0%, Fe balance, Al ≤1.5%, C ≤0.8% (typical impurities) |
| Form | Lumps (10-80mm), Granules (1-3mm, 3-15mm), Powder (0-2mm), Custom sizes, Cored wire (Ø9mm/13mm) |
| Application | Steelmaking (deoxidizer, desulfurizer, inclusion modification), nodulizer in ductile iron, calcium treatment |
| Standard | GB/T 2272-2020, ASTM A495, ISO 5445 |
Silicon Calcium 55-28 – Product Overview
Silicon Calcium 55-28 is a composite alloy containing high-purity silicon and calcium. Produced by electric furnace reduction, it combines the strong deoxidizing power of calcium with the alloying benefits of silicon. This grade (Si≥55%, Ca≥28%) is widely used in secondary steelmaking for inclusion shape control, desulfurization, and as a nodulizer in ductile iron production.
Product Core Advantages
- Balanced Composition: Minimum 55% Si and 28% Ca ensures efficient deoxidation and calcium recovery in molten steel.
- Inclusion Modification: Calcium modifies alumina inclusions to liquid calcium aluminates, improving steel cleanliness and castability.
- Nodulizing Efficiency: Effective magnesium-free nodulizer for ductile iron, providing good graphite nodularity.
- Custom Sizing & Forms: Available in lumps, granules, powder, or cored wire to suit different addition methods (ladle, tundish, wire feeder).
- Consistent Quality: Strictly controlled impurities (Al, C) ensure predictable metallurgical performance.
Typical Application Areas
- Steel Refining (Secondary Metallurgy): Added during tapping or ladle treatment for deep deoxidation, desulfurization, and inclusion engineering.
- Ductile Iron Production: Used as a nodulizing agent to produce spheroidal graphite cast iron (SGI).
- Foundry Inoculation: Acts as an inoculant to improve graphite structure and reduce chill in gray iron.
- Cored Wire Feeding: SiCa 55-28 is commonly processed into cored wire for precise calcium treatment in steel plants.
For specific application guidance, contact our technical team for personalized recommendations.
Technical Specifications – Silicon Calcium Alloys
Our Silicon Calcium 55-28 meets international standards. Below is the chemical composition compared with common industrial grades.
Chemical Composition (Typical Values, % by weight)
| Grade / Designation | Si (%) | Ca (%) | Fe (%) | Al (%) | C (%) |
|---|---|---|---|---|---|
| SiCa 55-28 | ≥55.0 | ≥28.0 | Balance | ≤1.5 | ≤1.0 |
| SiCa 50-20 | ≥50.0 | ≥20.0 | Balance | ≤1.5 | ≤1.0 |
| SiCa 58-30 | ≥58.0 | ≥30.0 | Balance | ≤1.5 | ≤0.9 |
| SiCa 59-30 | ≥59.0 | ≥30.0 | Balance | ≤1.5 | ≤0.8 |
| SiCa 60-30 | ≥60.0 | ≥30.0 | Balance | ≤1.0 | ≤0.6 |
| SiCa 60-32 | ≥60.0 | ≥32.0 | Balance | ≤1.5 | ≤0.6 |
Physical Properties
| Property | Value | Unit |
|---|---|---|
| Melting Range | ~1200-1300 | °C |
| Density (at 20°C) | ~2.5-2.8 | g/cm³ |
| Appearance | Silvery-gray metallic lumps / granules | - |
| Bulk Density (lumps) | 1.8-2.2 | g/cm³ |
Available Sizes & Forms
- Lumps: 10-50mm(standard), 10-80mm, 30-100mm , custom sizes available
- Granules: 1-3mm, 3-15mm
- Powder: 0-2mm, 0-3mm,0.2-2mm,0-0.2mm
- Cored Wire: Ø13mm (steel sheath, SiCa powder filling), custom core weight
- Custom Sizes: Available upon request
Application Guidelines – Silicon Calcium 55-28
SiCa 55-28 is essential in modern steelmaking and foundry processes:
Steelmaking (Calcium Treatment)
Added to molten steel (usually via cored wire or ladle addition) for inclusion modification: transforms solid Al₂O₃ inclusions into liquid calcium aluminates, preventing nozzle clogging and improving fatigue properties. Typical addition rates: 0.5-2 kg/ton steel.
Ductile Iron Nodulizer
Used in the production of spheroidal graphite iron (SGI) as a magnesium-free nodulizer. Provides good nodularity in heavy-section castings with reduced dross formation.
Desulfurization & Deoxidation
Calcium has high affinity for oxygen and sulfur. SiCa alloy is effective for deep desulfurization (S levels below 0.005%) in secondary metallurgy.
Foundry Inoculant
Acts as a late-stage inoculant to improve graphite morphology and reduce chill depth in gray and ductile iron castings.
Packaging & Logistics – Silicon Calcium 55-28
Packaging Options
- 1‑ton Jumbo Bags: Standard for lumps/granules.
- 25kg / 50kg Bags: For smaller orders or foundries.
- Cored Wire Spools: 1000-1500kg spools, moisture-proof wrapped.
- Custom Packaging: Moisture-proof liners, wooden boxes, small drums.
Logistics Information
| Parameter | Details |
|---|---|
| Minimum Order Quantity | 20 metric tons (lumps/granules); 10 tons for cored wire (trial orders negotiable) |
| Lead Time | 15-25 days after order confirmation |
| Port of Loading | Main Chinese ports (Tianjin, Shanghai, Qingdao) |
| Shipping Options | FOB, CIF, CFR, DAP |
| Payment Terms | T/T, L/C at sight |
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Frequently Asked Questions – Silicon Calcium 55-28
What is the main advantage of Silicon Calcium 55-28 over lower calcium grades?
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Higher calcium content (≥28%) ensures more efficient inclusion modification and deeper desulfurization, especially when using cored wire. It allows for lower addition rates and better calcium recovery.
Can SiCa 55-28 be used in cored wire?
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Yes, absolutely. SiCa 55-28 powder (0-2mm) is commonly used as filling powder for cored wire, typically Ø9mm or Ø13mm, for precise calcium injection in ladles or tundishes.
What sizes are best for ladle additions?
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For direct ladle addition, lumps 10-80mm are typical to ensure good penetration and dissolution. For wire feeding, powder 0-2mm is used.
Do you provide a certificate of analysis?
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Yes, every shipment includes a Certificate of Analysis (COA) showing Si, Ca, Fe, Al, C content, tested in our accredited lab.
What is your production capacity for SiCa alloys?
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Annual capacity exceeds 30,000 metric tons across all silicon calcium grades, including 55-28, 60-30, and cored wire.
Why Choose Our Silicon Calcium
20+ Years Experience
Specialized in ferroalloy production with deep industry knowledge
Strict Quality Control
Every batch tested to ensure consistent composition and performance
Global Delivery
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Different Grades of CaSi Comparison
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