Calcium silicon alloy 5528, designated Ca28Si60, is a high-performance composite alloy that precisely combines the powerful deoxidizing element calcium (Ca ≥28%) with the efficient alloying and deoxidizing element silicon (Si 55-65%). Its core value lies in achieving a "one-additive, multi-functional" effect-deep purification of molten steel and iron, control of inclusion morphology, and optimization of microstructure-through the synergistic effect of calcium and silicon. Compared to traditional single ferrosilicon or pure calcium additives, CaSi 5528 can more efficiently and economically solve the problem of sulfide and oxide control in high-end steel production, making it an indispensable strategic raw material for producing high-purity, high-strength, and high-toughness special steels and high-quality castings.

Calcium silicon alloy

Production process of calcium silicon alloy

The production process of calcium silicon alloy is generally divided into three stages: ore beneficiation, ore reduction and alloy smelting.

Ore beneficiation

The raw materials of SiCa alloy are mainly silica ore and calcium ore, such as limestone. First, the raw materials are beneficiated to remove impurities and improve their purity and reducibility.

Ore reduction

After mineral processing, the materials undergo a reduction reaction to reduce the oxides to the original metal. This stage mainly decomposes the oxides in silicon ore and calcium ore into silicon and calcium through high-temperature reduction reaction.

Alloy smelting

The silicon and calcium obtained after ore reduction will be further smelted to make calcium silicon alloy. The smelting process mainly includes steps such as burning, roasting, smelting, and refining. Through these processes, the silicon and calcium in the alloy will become a new substance, a silicon calcium alloy.

chemical composition

Parameter Category

5528 (Ca28Si60) Typical Specifications

Metallurgical Significance and Selection Guidelines

Core Components

Calcium (Ca): ≥ 28%
Silicon (Si): 55-65%

High calcium content ensures strong handling capabilities for sulfur, oxygen, and alumina inclusions; high silicon content provides a basis for auxiliary deoxidation and alloying, and contributes to a stable reaction process.

Key Impurity Control

Carbon (C): ≤ 1.0%
Aluminum (Al): ≤ 2.4%
Phosphorus (P): ≤ 0.04%, Sulfur (S): ≤ 0.06%

Strict low phosphorus and sulfur control avoids secondary pollution of molten steel; moderate aluminum content can assist deoxidation, but different aluminum content grades must be selected according to the final steel grade requirements.

Physical Form

Blocks: 10-50mm, 10-100mm (suitable for ladle additives)

Granules: 0-3mm, 3-8mm (suitable for wire feeding or casting inoculation)

Powder: Customizable (for special processes such as spraying)

Form selection depends on the process: lumps are used for routine addition; granules are used for precise control; powders are used for efficient dispersion and rapid reaction.

Products Uses

Calcium silicon alloy 5528 (containing about 55% silicon and about 28% calcium) has unique application advantages in multiple industrial fields due to its optimized composition. The main applications are as follows:

1. Steel industry

As a composite deoxidizer and desulfurizer for high-end steel production, it can reduce the oxygen and sulfur content of liquid steel, promote the floating of non-metallic inclusions, and improve the purity of steel. It is suitable for automotive steel (such as high-strength body steel plates, engine steel), aerospace steel (aircraft structural parts, engine parts raw materials) and electrical steel (improving electromagnetic properties, used in transformer and motor manufacturing).

2. Casting industry

It plays a role in deoxidation, purification and inoculation in casting, can refine and spheroidize graphite, reduce the tendency of white cast iron, increase silicon, desulfurize, and improve the structure and performance of cast iron. It is used in castings such as automobile engine cylinders, large mechanical parts, pipe fittings, etc., which can enhance wear resistance and heat resistance, improve processing performance, and reduce casting defects.

3. Other fields

Nonferrous metal smelting: It can be used as a refining agent for aluminum alloys, copper alloys, etc. to remove impurities and adjust alloy composition.

Chemical industry: It can be used as a catalyst or reducing agent to participate in chemical synthesis reactions that require reducing conditions.

New energy materials: It has application potential in the research and development of battery materials, hydrogen storage materials, etc.

SGS

Products Description

Q: What are the advantages of calcium silicon alloy 5528 compared to pure calcium wire or calcium-iron cored wire?

A: 5528 is a composite functional material. Pure calcium wire has a high calcium content but reacts violently and is expensive; calcium-iron wire has a low calcium content. The synergistic effect of silicon and calcium in 5528 makes its reaction more stable and controllable. The deoxidizing effect of silicon creates a better environment for calcium treatment, improving the calcium yield and the stability of the treatment effect, and has a more advantageous overall cost, making it especially suitable for large and medium-sized steel ladles.

Q: How to calculate and optimize the calcium treatment yield?

A: Yield = (Calcium absorbed by molten steel / Total calcium added) × 100%. Key optimization points: 1) Treatment timing: Perform after sufficient deoxidation and desulfurization ([S]≤0.015%); 2) Addition depth: Ensure the alloy is added to the lower part of the ladle (1/2-2/3 depth); 3) Stirring intensity: Combine with appropriate bottom-blowing argon stirring. Based on our project experience, using 5528 block alloy, the calcium recovery rate can be stably maintained at 20%-35% under good processing conditions.

Q: What is the optimal addition amount when used for casting inoculation?

A: As an inoculant, the recommended addition amount is 0.1%-0.3% of the weight of the molten iron. The specific amount needs to be determined experimentally based on the sulfur content of the original molten iron, the target spheroidization rate, and the casting wall thickness. Excessive addition may lead to an increased tendency for shrinkage porosity in the casting or an increase in slag volume.

calcium silicon alloy 5528