Ferro Silicon Calcium(also known as Calcium Silicon or CaSi) is a high-performance composite alloy, meticulously engineered to serve as a powerful deoxidizer, desulfurizer, and inclusion modifier in the production of clean steel and high-quality cast iron. By combining the strong deoxidation power of silicon with the unique inclusion-modifying capabilities of calcium, this alloy offers a synergistic solution for enhancing steel purity, improving castability, and boosting the mechanical performance of the final product. Available in various grades (e.g., Ca31Si60, Ca28Si60), it is an essential tool for modern metallurgists aiming to meet stringent quality standards.

Calcium silicon is an alloy composed of calcium (Ca) and silicon (Si), which is commonly used in industries such as steel smelting and casting. Its main components are calcium and silicon, usually containing a certain proportion of calcium and silicon, with the calcium content generally between 20%-40% and the silicon content between 30%-70%.

Calcium Ferro Silicon

chemical composition

Brand	Chemical Composition %
	Ca	Si	C	Al	P	S
	≥	≥	≤
Ca31Si60	31	55-65	1.0	2.4	0.04	0.06
Ca28Si60	28	55-65	1.0	2.4	0.04	0.06
Ca24Si60	24	55-65	1.0	2.5	0.04	0.04
Ca20Si55	20	50-60	1.0	2.5	0.04	0.04
Ca16Si55	16	50-60	1.0	2.5	0.04	0.04

In-Depth Technical Application Guide

1. Steel Refining: Deoxidation, Desulfurization & Inclusion Engineering

In secondary steelmaking (e.g., in LF or RH vessels), Ferro Silicon Calcium plays a multifaceted role:

Efficient Deoxidation:

Silicon provides primary deoxidation, while calcium further reacts with dissolved oxygen, forming stable oxides that float into the slag, leading to cleaner steel.

Powerful Desulfurization:

Calcium has a high affinity for sulfur. It reacts to form calcium sulfide (CaS), which is effectively removed into the slag, significantly lowering the sulfur content. This is critical for improving steel's toughness, ductility, and resistance to hydrogen-induced cracking (HIC).

Inclusion Morphology Control (Its Most Critical Role):

In aluminum-killed steels, hard, brittle alumina (Al₂O₃) inclusions can severely reduce fatigue life. Calcium from the alloy modifies these into less harmful, liquid calcium aluminates that remain spherical and small, dramatically improving the steel's mechanical properties and machinability.

2. Foundry Industry: High-Performance Inoculant for Cast Irons

In the production of ductile (nodular) and gray cast irons, Silicon Calcium is a highly effective inoculant:

Graphite Nucleation:

It promotes the formation of numerous graphite nuclei during solidification. This results in a uniform distribution of fine, Type A graphite in gray iron and a high nodule count in ductile iron.

Chill Reduction:

It effectively reduces the tendency for forming hard, brittle carbide structures (chill) at casting edges, improving machinability and reducing tool wear.

Property Enhancement:

By refining the graphite structure, it significantly enhances the cast iron's tensile strength, wear resistance, and overall mechanical performance.

3. Alloying Agent for Specialty Steels

In the production of certain high-alloy or specialty steels (e.g., heat-resistant steels, some stainless grades), Ferro Calcium Silicon can be used as a precise alloying addition to introduce controlled amounts of calcium and silicon for specific property improvements, such as enhancing high-temperature strength or oxidation resistance.

Calcium Ferro Silicon

Tailored Solutions for Your Unique Process

We recognize that every steel mill and foundry operates with specific targets and equipment. Beyond our standard grades, we offer comprehensive customization to optimize your results:

Custom Chemistry: Need a specific Ca/Si ratio or tighter controls on impurities like Al or P? We can tailor the alloy formulation to meet your exact steel or iron specifications.

Bespoke Physical Forms: We provide Calcium Silicon in various forms to suit your handling and feeding systems:

Lumps (e.g., 10-100mm): For traditional ladle additions.

Granules (e.g., 1-10mm): For automated and continuous feeding systems in refining stations.

Powder: For injection or use in cored wire production.

Technical Partnership: Our experienced metallurgists are available to provide guidance on optimal addition rates, methods, and grade selection to help you achieve your quality goals efficiently.

Ferro Silicon Calcium

FAQ

Q: How do I choose between different grades like Ca31Si60 and Ca24Si60?
A: The choice depends on your primary objective. High-calcium grades like Ca31Si60 are most effective when strong inclusion modification (e.g., for bearing or pipeline steels) or deep desulfurization is required, as they provide a higher calcium potential. Grades with lower calcium, like Ca24Si60 or Ca20Si55, are often more cost-effective for general deoxidation in carbon steel or as a foundry inoculant, where a balanced effect is sufficient. Our technical team can help you select the optimal grade based on your specific steel grade and process.

Q: What size is recommended for use in a wire feeding system vs. manual ladle addition?
A: For manual ladle addition or furnace tapping, we typically recommend lump sizes like 10-60mm or 10-100mm to ensure smooth penetration and dissolution without excessive oxidation. For automated wire feeding systems, the material is usually processed into a specific granular size (e.g., 0-3mm or 1-5mm) to ensure consistent flow and rapid, deep reaction in the molten steel. We can customize the sizing to perfectly match your equipment and process requirements.