Ferro Silicon 75 (FeSi75) is the most widely used silicon alloy in global steelmaking and foundry industries. With standard silicon content 74%-76%, low harmful impurities and stable metallurgical performance, it acts as a core deoxidizer, alloying agent and inoculant. Proper usage can effectively improve molten steel quality, adjust material mechanical properties and cut production cost.
Core Functions of FeSi 75
Powerful Deoxidation
It removes excess oxygen in molten steel rapidly, reduces oxide inclusions, avoids air holes and cracks inside finished products, and improves material compactness.
Alloying Adjustment
Supplement silicon element accurately to enhance steel strength, hardness, wear resistance and elastic performance, widely used in spring steel, structural steel and low alloy steel production.
Graphite Nucleation Inoculation
In cast iron production, FeSi75% promotes uniform graphite precipitation, optimizes internal structure, improves casting toughness and reduces shrinkage defects.
Temperature Raising Agent
It releases obvious heat during reaction with molten steel, helps stabilize furnace temperature and shorten smelting cycle.
Standard Grade & Quality Requirement
To ensure stable using effect, international mainstream buyers accept below specifications:
Silicon: 74% ~ 76%
Carbon ≤0.2%, Sulfur ≤0.03%, Phosphorus ≤0.03%
Regular size: 10-50mm, 3-15mm, customized sizes available
Low-impurity FeSi75 is preferred for high-grade steel and precision casting production.
Correct Usage Methods in Steelmaking
Adding Time
Add FeSi 75 after tapping molten steel or during ladle refining. Do not put it into furnace in early smelting stage, to avoid excessive burning loss and low recovery rate.
Recommended Dosage
Common carbon steel: 2.0kg ~ 4.0kg per ton molten steel
Low alloy steel & spring steel: 4.0kg ~ 8.0kg per ton molten steel
Adjust dosage according to initial silicon content and final component standard.
Operation Tips
Put ferro silicon evenly into molten steel flow for fast melting and uniform mixing.
Control molten steel temperature between 1550℃-1600℃ to guarantee high silicon recovery rate.
Match with manganese alloy for better comprehensive deoxidation effect.
Application in Foundry Industry
Grey Cast Iron & Ductile Iron
Use FeSi75 as primary inoculant, add during ladle pouring process to refine grain structure, improve casting fluidity and surface finish.
Prevent Casting Defects
Reasonable silicon addition effectively reduces cold shut, porosity and shrinkage cavity, lowers finished product rejection rate.
Usage Advantage
Compared with other silicon alloys, FeSi75 has lower comprehensive cost and more stable inoculation effect, ideal for mass casting production.
Key Notes for Better Using Effect
Keep FeSi75 sealed and dry storage, avoid moisture which will cause molten steel splashing.
Control feeding quantity strictly, excessive silicon will lead to increased material brittleness.
Choose matched size: large particles for large furnace, fine particles for precision smelting.
Regularly test molten steel composition to stabilize finished product mechanical performance.
FerroSilicon 75% remains the cost-effective and reliable metallurgical material for modern steelmaking and foundry fields. Mastering correct adding time, reasonable dosage and standard operation rules can maximize its deoxidation, alloying and inoculation value. For steel manufacturers and casting enterprises, stable-quality FeSi75 plus scientific using method is an effective way to improve product quality and optimize production benefit.
