Ferro-Silicon (FeSi 75) – Alloying / Deoxidizer
Ferro-Silicon (FeSi) is a master alloy of Iron (Fe) and Silicon (Si). The 75% grade indicates that the alloy contains 72% to 78% Silicon, making it highly concentrated and widely preferred for its efficiency. FeSi is a multi-functional additive, serving primarily as a powerful deoxidizer and a critical alloying element to enhance the strength, elasticity, and magnetism of steel and cast iron.
Main Function and Mechanism
Silicon is a crucial element for controlling oxygen activity, improving steel microstructure, and stabilizing the casting process.
| COMPONENT | CHEMICAL SYMBOL | PROPERTY HIGHLIGHT |
| Silicon | Si | Strong deoxidizer, graphitizer in cast iron, solid solution strengthener in steel. |
| Iron | Fe | Carrier metal; aids dissolution and density. |
| CLASSIFICATION | MELTING POINT | PRIMARY APPLICATION FOCUS |
| Alloying/Deoxidizer | ~1300°C (2372 F) | Production of Carbon Steel, Electrical Steel, and Cast Iron. |
Key Performance Metrics
| PROPERTY | ROLE AS DEOXIDIZER | ROLE AS ALLOYING ELEMENT |
| Oxygen Affinity | HIGH | None |
| Strength/Elasticity | None | Increases tensile strength and improves elastic limit (e.g., spring steel). |
| Cast Iron Control | None | Promotes the formation of graphite (improving machinability and volume stability). |
| Cost-Effectiveness | HIGH | HIGH |
1. Deoxidation (The Primary Function)
Silicon is the most common deoxidizing agent after manganese. It is added to molten steel to remove dissolved oxygen (O) before casting, preventing the formation of gas blowholes and ensuring a sound casting structure:
- Mechanism: Silicon reacts with oxygen to form a solid, high-melting silica (SiO2) inclusion. This inclusion, when combined with MnO (from FeMn addition), forms liquid manganese silicates that easily float out and are absorbed by the slag.
- Semi-Killed Steel: FeSi is the main additive used to produce semi-killed steel, providing enough deoxidation to ensure a sound body while allowing a beneficial amount of oxygen to remain for controlling the ingot top.
2. Alloying (Structural and Electrical Steel)
The silicon that remains dissolved in the final steel (residual Si) acts as a strong alloying element:
- Spring Steel: Si (typically 1.5% to 2.0%) is added to spring steels to increase the elastic limit and strength, allowing the steel to withstand high stress without permanent deformation.
- Electrical Steel: High purity FeSi is critical for the production of grain-oriented and non-grain-oriented silicon steel (transformer steel). The Si content (up to 3.5%) increases the material’s electrical resistivity and reduces magnetic core losses, making it ideal for high-efficiency electrical equipment.
3. Cast Iron and Foundry Use
- Inoculation: In cast iron, FeSi is the main source of silicon, where it functions as a graphitizer. Silicon promotes the formation of soft, machinable graphite flakes (gray iron) or nodules (ductile iron), instead of hard, brittle iron carbides. Specialty fine-particle FeSi is added right before pouring (inoculation) to control the casting microstructure.
Technical Guidance and Form
- Grade Selection: 75% FeSi is preferred over 45% FeSi due to its higher active Si content and lower iron content, which often translates to higher purity and more cost-efficient addition.
- Dissolution: FeSi is dense and has a relatively low melting point, allowing it to dissolve quickly and efficiently when added as crushed lumps or granules to the ladle.
- Exothermic Reaction: Some specialized FeSi grades are blended to be slightly exothermic (heat-releasing) when added, further aiding dissolution and reducing the chilling effect on the molten metal.
✨ Customization Services
We offer product customization services, allowing you to tailor the appearance, dimensions, or specific markings of items like refractory shapes or bricks. This includes options for incorporating specific geometric requirements to ensure seamless integration into your process systems.
🔬 Sampling for Testing & Validation
Free product samples are available for thorough testing and validation. This allows you to confirm the quality, compatibility, and performance of our materials—such as specific bricks, castables, or raw materials—before committing to a full order.
💡 Expertise in Refractory Solutions
Leverage our deep expertise to receive detailed, application-specific refractory solutions. We move beyond just selling products by providing comprehensive plans that encompass material selection, installation guidance, and performance optimization to maximize the lifespan and efficiency of your high-temperature processes.
Rabatec products are exclusively manufactured in facilities that have achieved rigorous ISO certifications across Quality (ISO 9001), Environmental Management, and Occupational Health & Safety. This commitment ensures every product, from refractory bricks to specialized equipment, meets the highest global benchmarks for performance, sustainability, and workplace safety.
📦 Logistics Excellence: Shipping, Packaging, and Marking
Minimizing Risk: We manage all logistics to minimize handling touchpoints and transit shock. Our carriers are pre-vetted for their experience in transporting heavy, fragile, and sensitive industrial materials.
Traceability: Every shipment includes comprehensive documentation and tracking information, providing end-to-end visibility and ensuring precise delivery coordination for your site.
Protection is Paramount: Our packaging strictly follows industry standards to prevent damage, corner chipping, and moisture absorption—especially critical for materials like Basic Refractory Bricks and Refractory Mortars & Mixes.
Robust Palletization: Products are secured on fumigated, high-strength export pallets (e.g., 1100x950mm or similar sturdy dimensions) using heavy-duty strapping and durable protective wrapping (polyethylene sheeting, cardboard, etc.) to withstand long-distance travel and multiple loadings.
Moisture Control: Sensitive materials are protected with appropriate sealing and, where necessary, desiccants or moisture-vapor proof enclosures to maintain the product's integrity until installation.
Clear Identification: All outer packaging is clearly marked on multiple sides with large, legible text for immediate identification and safe handling.
Full Traceability: Markings include all essential data points: Product Name, Quality Grade, Batch Number, Quantity, Net/Gross Weight, Order Number, and the Final Destination/Construction Area. This ensures every pallet can be accounted for and correctly staged upon arrival.
Safety & Compliance: We adhere to all regulatory requirements for marking, labeling, and placarding—especially for any items classified as Dangerous Goods—to ensure full compliance with international and domestic transport regulations.
❓ Frequently Asked Questions (FAQ)
Question | Elaborated Answer |
Q: What is the Refractoriness Under Load (RUL) of your refractories? | A: Refractoriness Under Load (RUL) is a critical property that defines the maximum temperature our materials can withstand while under compressive stress before deforming (softening). Since we offer a wide range of materials—from Alumina-Silicate Bricks to high-performance Silicon Carbide Bricks—the RUL varies significantly. For specific product data, please refer to the product data sheet or submit a quote request for the material you are interested in. |
Q: Where are the Rabatec refractories and materials produced? | A: Our products are primarily sourced from specialized manufacturing plants in China. Crucially, these facilities have all undergone rigorous audits and achieved comprehensive ISO certifications (Quality, Environment, and Safety), ensuring that production adheres to the highest global standards for consistency and performance. |
Q: What refractory materials does the company offer? | A: We supply a comprehensive portfolio of advanced refractory solutions, including: Shaped Products: Alumina & Silica Bricks, Basic & Specialized Bricks (e.g., Magnesia), SiC & Structural Ceramics, and Precast Shapes. Monolithic Products: Refractory Castables, Mixes & Mortars. Insulation: Insulation Fibre and High-Performance Insulation Products. |
Q: How should I choose the appropriate refractory material for my application? | A: Selecting the correct refractory is paramount to process efficiency. The choice depends on three key factors: 1. Operating Environment: Maximum process temperature and thermal cycling (shock). 2. Chemical Attack: Type of slag, molten metal, or corrosive gas being handled (acidic, neutral, or basic). 3. Mechanical Stress: Abrasion, erosion, and static load requirements. We recommend utilizing our detailed refractory solutions service to consult with our engineers for an optimized, application-specific recommendation. |
Q: Which monolithic material should I choose when patching an existing lining? | A: For patching and minor repairs, the ideal monolithic material depends on the parent lining material, the patching depth, and the need for a rapid return to service. Common choices include: Refractory Mortars & Mixes (for minor joints/surfaces) or Plastic Refractories (for areas requiring physical compaction). Always choose a patch material chemically compatible with the existing lining to ensure proper bonding and service life. |
Q: Can I receive product samples before placing a major order? | A: Yes. We gladly provide product samples for your internal testing and validation purposes. This ensures you can confirm the quality, composition, and fit of the material—such as our Refractory Castables or Alumina-Silicate Bricks—in your specific operational environment before committing to a bulk purchase. |
Q: Do you provide certifications to verify material quality? | A: Absolutely. We provide product-related inspection certificates and quality assurance documentation upon request. This verifies that your order has passed all internal quality control checks and meets the required material specifications and industry standards. |
Q: What measures are taken for product protection during transport? | A: We ensure quick, reliable transport by using robust, industrial packaging that strictly follows industry standards. This includes high-strength palletization, heavy-duty strapping, and weather-resistant wrapping to protect fragile items like bricks and mixes from corner chipping, mechanical damage, and moisture during transit. |
