FeSi

Ferro Silicon

Also known as: Ferrosilicon · FeSi75 · FeSi72

Ferro Silicon (FeSi) is an iron-silicon master alloy used to control oxygen and adjust silicon content in molten steel and cast iron. As a deoxidizer, its silicon reacts with dissolved oxygen to form SiO2 that floats into the slag, raising cleanliness and improving yield of more reactive additions such as Mn and Al. In cast iron it shifts solidification toward graphite, countering chill and stabilizing the as-cast structure. This grade runs Si 72-78% (FeSi 75 basis) with Al ≤ 1.5%, C ≤ 0.10%, P ≤ 0.04%, and S ≤ 0.02% in 10-60 mm lumps. Typical use spans EAF and BF-BOF steel deoxidation, grey- and ductile-iron inoculation, silicon-steel production, and as feedstock for downstream ferroalloys. Deoxidation dosage commonly lands near 0.3-0.6 wt% for grey iron, adjusted to bath chemistry and oxygen activity. Tight C/P/S limits suit cleaner-steel routes; a 70-72 grade is available for grey-iron and inoculation work. Lots ship against COA (EN 10204 3.1) and MTC with XRF/ICP verification, conforming to ASTM A100 / ISO 5445, from multi-regional sourcing. Delivery options include CIF Marmara, Gebze bonded stock, and 20 MT FCL lots. Send your grade and tonnage for an RFQ.

Technical Specifications

Si	72-78%
Al	≤ 1.5%
C	≤ 0.10%
P	≤ 0.04%
S	≤ 0.02%
Size	10-60mm

Arsam Standard

Grades	FeSi 75 (Si 72-78%) · 70-72 grade (grey iron / inoculation)
International Reference	ASTM A100 · ISO 5445
Packaging	1 MT jumbo big bag · Palletized · FCL container
Documentation	COA (EN 10204 3.1) · MTC · Radiation certificate · CoO · EUR.1 / A.TR (EU)
Quality Control	XRF/ICP · 0.3-0.6 wt% grey-iron deoxidation dosage reference
Minimum Order	20 MT FCL / 5 MT LCL
Incoterms	FOB / CIF / CFR / DAP
Lead Time	Sea CIF 28-35 days · Gebze bonded stock 24-48h · alternative road/ferry 12-21 days

International standards are a reference basis; certificates provided on request with document verification.

Applications

Steel deoxidation

Cast iron inoculation

Ferroalloy production

Silicon steel

Frequently Asked Questions

What is the difference between FeSi75 and the 70-72% silicon grade?

Silicon content. FeSi75 (Si 72-78%, Al ≤ 1.5%) is the standard grade for deoxidation and silicon adjustment in steel. The 70-72% grade is used in some grey iron applications. Which one fits depends on your process and target chemistry; we can quote both side by side.

What should the FeSi dosage be in grey iron?

The typical range is 0.3-0.6% (aiming at 1.5-2.5% Si in the bath), which is roughly 36-72 kg of FeSi75 for a 12 t charge. The foundry's metallurgy team sets the exact amount; we can work through the calculation with you.

When is FeSi preferred over silicon carbide (SiC)?

FeSi75 adds silicon only and is used for deoxidation and silicon adjustment. Silicon carbide (SiC ≥ 90%) adds both silicon and carbon (about 63% Si and 27% C) and supports nucleation in induction melting, so it is preferred when carbon is also needed. Many foundries use both at different stages.

What is the FeSi lead time for foundries in Türkiye?

From the Gebze bonded warehouse, 24-48 hours when stock is held. Sea freight CIF Gemlik takes 28-35 days; road and ferry 12-21 days.

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