Ferrosilicon 75% — Essential Deoxidizer and Alloying Agent
Ferrosilicon

Ferrosilicon 75% — Essential Deoxidizer and Alloying Agent

Standard FeSi 75% ferrosilicon alloy, the workhorse deoxidizer and silicon source in steelmaking. Provides reliable silicon recovery for deoxidation, alloying, and cast iron inoculation across the full spectrum of steel grades.

Specifications

Si Content
74–80%
Al Content
≤1.5%
C Content
≤0.2%
P Content
≤0.04%
S Content
≤0.02%

Features

  • Industry-standard FeSi 75 grade with tight silicon range ensures predictable recovery and consistent steel composition
  • Low aluminum content minimizes alumina inclusion generation, reducing the risk of nozzle clogging during continuous casting
  • Available in multiple size ranges (lumps, nuts, fines) for different addition methods and furnace types
  • Essential for cast iron inoculation where controlled silicon addition promotes graphite nucleation and improves mechanical properties

Applications

Primary deoxidation in all steelmaking routes (EAF, BOF, induction) for silicon-killed and semi-killed steel gradesSilicon alloying in structural steel, spring steel, electrical steel, and heat-resistant steel grade productionInoculation of gray iron and ductile iron castings to control graphite morphology and improve machinabilityReducing agent in the production of other ferroalloys and as a silicon source in magnesium ferrosilicon nodularizers

Industries

SteelmakingFoundry and CastingFerroalloy Production

Ferrosilicon 75% is the most widely consumed ferroalloy in the global steel industry, serving as the primary source of silicon for both deoxidation and alloying purposes. In deoxidation applications, silicon reduces dissolved oxygen to form silica (SiO2), which is less disruptive to continuous casting than the alumina (Al2O3) produced by aluminum deoxidation. For this reason, silicon-killed steel grades—particularly those destined for structural applications, pipelines, and shipbuilding—rely on ferrosilicon as the primary deoxidizer. The FeSi 75 grade delivers approximately 1.5 kg of active silicon per kilogram of alloy added, with typical recovery rates of 75–90% depending on the steelmaking route and addition practice.

In alloying applications, ferrosilicon is the principal means of introducing silicon into steel grades where silicon contributes to mechanical properties, electrical properties, or oxidation resistance. Structural steels typically contain 0.15–0.35% silicon, which acts as a solid-solution strengthener. Spring steels (such as AISI 9260) contain 1.80–2.20% silicon for enhanced elastic properties and fatigue resistance. Electrical silicon steels used in motor and transformer cores require silicon contents of 2.0–3.5% (non-oriented) or up to 3.3% (grain-oriented), with ferrosilicon being the most economical source for these high-silicon additions. Each of these applications demands precise silicon control, making the consistent 74–80% Si content of our FeSi 75 essential for reliable alloy management.

The foundry industry represents another major consumption sector for ferrosilicon, where it serves dual roles as a silicon booster in base iron production and as a key component in inoculants for gray and ductile iron. In inoculation, small additions of ferrosilicon-based inoculants (0.1–0.3% by weight) to molten iron immediately before pouring promote the nucleation of type A graphite flake morphology in gray iron or enhance nodule count in ductile iron. Our ferrosilicon is available in size ranges from 10–100 mm lumps for furnace additions down to 0–3 mm fines for foundry inoculation, ensuring the right product for every application.

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