Calcium silicon (CaSi) is a critical ferroalloy in modern casting processes, valued for its ability to refine microstructure, enhance mechanical properties, and reduce defects in cast iron and steel. Specifically engineered for foundry applications, silicon calcium products-including lumps, powders, and cored wires-deliver precise control over graphite formation, deoxidation, and alloying.

CaSi for casting is a ferroalloy composed primarily of calcium (Ca: 28-35%), silicon (Si: 55-65%), and trace iron (Fe: 3-8%), with strict impurity control (Al ≤2.0%, C ≤0.5%, P ≤0.04%). Its unique chemistry makes it dual-functional in casting:

Inoculant: Promotes uniform graphite nucleation, preventing brittle "chill" (white iron) formation.
Nodulizer auxiliary: Enhances graphite spheroidization in ductile iron, working synergistically with magnesium-based alloys.
Deoxidizer: Removes dissolved oxygen from molten metal, reducing oxide inclusions that cause porosity and cracks.

Available in lumps (5-50mm), powders (0.5-3mm), and cored wires (13-18mm diameter), it adapts to diverse casting processes-from sand casting to investment casting.

Calcium silicon (CaSi)

Key Types of Calcium Silicon for Casting Applications

Casting-specific silicon calcium products are tailored to process needs, with size and form determining their use case:

Product Type	Size	Typical Application	Core Advantage
Calcium Silicon Lumps	10-50mm	Large ladle gray iron inoculation	Slow, sustained reaction; ideal for batch casting.
Calcium Silicon Powder	0.5-3mm (20-80 Mesh)	Small-batch gray iron & ductile iron	Rapid dissolution; uniform distribution in small furnaces.
Calcium Silicon Cored Wire	13-18mm diameter	Continuous casting lines & large ductile iron pours	Precise dosing; minimal dust loss (90%+ utilization).

Critical Note: High-calcium grades (Ca ≥30%) are preferred for nodularization, while medium-calcium (Ca 28-30%) excel in inoculation-both outperform low-calcium alternatives in reducing casting defects.

Advantages Over Traditional Casting Additives

Calcium silicon outperforms alternatives like ferrosilicon, pure calcium, or rare earth alloys in key metrics:

Additive	Calcium Silicon	Ferrosilicon (75%)	Pure Calcium
Graphite Nucleation	Excellent (dual Ca+Si effect)	Moderate (only Si)	Poor (no Si for nucleation)
Sulfur Binding Capacity	High (Ca reacts with S)	None	High, but volatile (30-40% loss)
Cost-Effectiveness	High (single additive for multiple roles)	Low, but requires secondary additives	Low, but high dosage needed (wasted material)
Handling Safety	Stable (low reactivity with air)	Stable	Highly reactive (risk of explosions)
Defect Reduction	30-50% fewer cracks/porosity	10-15% reduction	20-25% reduction, but inconsistent

Calcium silicon

Application Guidelines for Optimal Results

To maximize calcium silicon's effectiveness in casting, follow these process-specific recommendations:

1. Gray Iron Inoculation

Addition Timing:

1-3 minutes before pouring (ladle inoculation) or in the stream (stream inoculation).

Dosage:

0.2-0.6% of molten iron weight (0.2-0.3% for thin sections, 0.4-0.6% for thick sections ≥50mm).

Size:

1-3mm powder for stream inoculation; 10-30mm lumps for ladle addition.

Tip:

Combine with 0.1-0.2% barium silicon for extended inoculation effect (up to 30 minutes vs. 15 minutes with calcium silicon alone).

2. Ductile Iron Nodularization

Addition Method:

Mix 5-10% calcium silicon with magnesium ferrosilicon (MgFeSi) in the nodulizer treatment ladle.

Dosage:

0.8-1.2% total (including MgFeSi), with calcium silicon comprising 15-20% of the nodulizer blend.

For Continuous Casting:

Use calcium silicon cored wire (16mm diameter) fed at 2-4 m/s to maintain consistent Mg/Ca levels.

Tip:

Control residual calcium in final castings at 0.002-0.005%-excess (>0.006%) causes graphite degeneration.

Partner With Us for Casting-Grade Calcium Silicon

As a leading supplier of foundry additives, we offer calcium silicon tailored for casting:

Custom Formulations: Grades optimized for gray iron (Ca28Si60) and ductile iron (Ca32Si60).
Technical Support: Free on-site guidance on dosage, mixing, and process optimization.
Quality Assurance: Each batch includes a test report with Ca/Si content, size, and impurity levels.

Contact us today to request a free sample (1kg) and a customized quote-elevate your casting quality with our high-performance calcium silicon.

calcium silicon