Ferrosilicon 72 (abbreviated as FeSi72) is a mainstream cost-effective ferrosilicon alloy. Its silicon content ranges from 72% to 75%, with iron as the main residual component and strictly controlled trace impurities including Al, Ca, P, S and C.

Balancing metallurgical performance and procurement cost perfectly, FeSi72% delivers better deoxidation and alloying effects than low-grade FeSi65, while being more economical than high-purity FeSi75%. Widely known as a foundational metallurgical material, it is extensively used for deoxidation, alloying in steelmaking and inoculation in foundry industries. With over 15 years of production experience, AON Metals operates fully automated submerged arc furnace production lines. We supply qualified FeSi72 to steel mills, foundries and magnesium smelting enterprises across Asia, Europe and America, and provide targeted technical solutions for different production lines.

FerroSilicon 72

Products Description

Category	Parameter	Standard Value	Industrial Interpretation & Selection Guide
Main Component	Silicon (Si)	72.0 ~ 75.0 %	Optimal cost-performance range for conventional steel and cast iron, lowest unit silicon cost
Trace Impurities	Carbon (C)	≤0.2% (Class B)	Suitable for most carbon steel; choose Class A (C≤0.1%) for ultra-low carbon steel
	Phosphorus (P)	≤0.04%	Avoid cold brittleness of finished metal, core index for structural steel
	Sulfur (S)	≤0.02%	Prevent hot cracking of steel and castings
	Aluminum (Al)	0.5 ~ 2.0%	Auxiliary deoxidation; adjustable per customer requirements
Physical Form	Lump	10-50mm, 10-100mm	For converter and electric furnace direct feeding
	Granule	1-3mm, 3-8mm	For ladle refining and in-flow inoculation
	Powder	0~1mm, Custom mesh	For injection metallurgy and special processes

Comparison with FeSi75

Comparison Item	Ferrosilicon 72 (FeSi72)	Ferrosilicon 75 (FeSi75)	Selection Suggestion
Silicon Content	72.0 ~ 75.0%	74.0 ~ 80.0%	FeSi72 for cost-sensitive mass production
Deoxidation Efficiency	High, meets conventional production needs	Slightly higher	No obvious difference for ordinary carbon steel
Comprehensive Cost	3%~5% lower per ton of steel	Higher	Preferred for large-scale steel mills and foundries
Impurity Control	Standard grade	High-purity grade	FeSi75 for high-end alloy steel
Main Application	Rebar, wire rod, gray iron, magnesium smelting	High-quality carbon steel, ductile iron	Select based on final product grade

ferrosilicon 72%

Widely used fields

Carbon Steel & Low-alloy Steel Production

FeSi72 acts as primary deoxidizer and alloy additive. It rapidly removes dissolved oxygen in molten steel, reduces oxide inclusions, and improves the compactness and fatigue resistance of steel. For high-strength low-alloy steel, silicon plays a solid solution strengthening role. Using FeSi72 can effectively control production costs while guaranteeing product performance, which is widely applied to construction rebar, wire rod and medium steel plate.

Foundry Industry

Gray Iron: Used as high-efficiency inoculant to promote the formation of Type A graphite, eliminate white cast defects, and improve machinability of castings. Ideal for machine tool beds, engine blocks and other large castings.
Ductile Iron: Serves as auxiliary inoculant to stabilize molten iron status and optimize graphite spheroidization effect.

Magnesium Smelting & Ferroalloy Manufacturing

As the core reducing agent for Pidgeon magnesium production, it reacts with magnesium oxide to generate magnesium vapor. It is also used as silicon source for producing Ca-Si, Si-Ba and other composite ferroalloys.

Welding Materials & Ordinary Alloys

Added to welding electrode coatings to improve weld strength and deoxidation performance. It is also used to adjust silicon content of spring steel and wear-resistant steel.

72 Ferrosilicon (FeSi72)

FAQs About 72 Ferrosilicon

Q: What are the most important indicators to consider when purchasing ferrosilicon 72?

A: Besides the silicon content range, the phosphorus (P) and sulfur (S) content must be carefully monitored, as they directly affect the quality of molten steel. For casting applications, the aluminum (Al) and calcium (Ca) content also affect the inoculation effect. Suppliers should be required to provide detailed batch chemical analysis reports, not just a specification range.

Q: How to avoid purchasing products with unsuitable size?

A: Clearly specify the size specifications and distribution requirements in the contract (e.g., 10-50mm ≥90%, <10mm powder ≤5%). Uneven size can lead to splashing during addition, unstable yield, and potential blockage of the feeding system. Suppliers can be requested to provide size sieving reports.

Q: How to calculate the approximate addition amount when using ferrosilicon 72?

A: Basic formula: Addition amount (kg) = [Molten steel quantity (t) × Target silicon addition (%)] / [Ferrosilicon silicon content (%) × Silicon yield (%)]. Silicon yield is affected by the process, typically ranging from 85% to 95% during the steel tapping process and 75% to 85% when added to the ladle. Small-scale trial calibration is recommended for first-time use.

ferrosilicon 72