The carbon content of ferrosilicon is a core indicator determining its performance focus and application boundaries. Low-carbon ferrosilicon (C≤1.0%), with its "low impurities and excellent toughness," is suitable for high-end steels and precision applications. High-carbon ferrosilicon (C1.0%-2.0%), with its "high hardness and strong wear resistance," dominates special steels and wear-resistant applications. Precise matching of carbon content directly affects the quality of steel/castings and production costs.
Comparison of feSi Carbon Content Grading and Core Characteristics
| Comparison Dimension | Low Carbon Ferrosilicon | High Carbon Ferrosilicon | Core Impact |
| Carbon (C) content range | ≤0.1% (high-end grade ≤0.05%), 0.1%-1.0% (ordinary low-carbon) | 1.0%-1.5% (mainstream), 1.5%-2.0% (high carbon grade) | Carbon content determines the balance between hardness and toughness; low carbon ensures purity and toughness, while high carbon enhances hardness and wear resistance. |
| Core components (Si/Fe) | FeSi75 Low-carbon type: Si 72%-80%, Fe 20%-28% | FeSi65 high carbon type: Si 63%-70%, Fe 30%-37% | LC ferrosilicon has a higher silicon content, resulting in better deoxidation; hc ferrosilicon has a higher iron content, leading to more significant alloying strengthening. |
| Impurity content (S/P/Al) | S≤0.03%,P≤0.04%,Al≤1.2% | S≤0.05%,P≤0.06%,Al≤1.5% | Low carbon fesi has higher purity, making it suitable for high-end applications. |
Note: Carbon is a core functional element-low carbon prevents embrittlement of steel/castings, ensuring electromagnetic properties and weldability; high carbon forms a Fe₃C-SiC composite hard phase with silicon and iron, significantly improving hardness and wear resistance, but excessive carbon can easily lead to cold brittleness.
Depending on the carbon content, the following differences in usage exist.
Steelmaking field
Low carbon ferrosilicon: LC FeSi with a carbon content of less than 1.0% has good deoxidation and alloying effects. It can effectively reduce the oxygen and sulfur content in molten steel, improve the quality of molten steel, enhance heat treatment performance, and improve the fluidity and fluidity of molten steel. Forgeability is mostly used in the smelting production of general carbon steel, alloy structural steel, special steel and alloy steel, etc.
High-carbon ferrosilicon: HC FeSi with a carbon content of 1.0%-2.0% has a stronger alloying effect and can significantly improve the hardness and strength of molten steel. It is mostly used to add alloys to special steel types, such as stainless steel, heat-resistant steel, and resistant steel. Charges for corroded steel, carbide steel, etc.
Cast iron field
Low carbon ferrosilicon: In the production of gray cast iron, low carbon ferrosilicon can be used as an inoculant to promote graphitization, improve the shape and distribution of graphite, make the cast iron structure more uniform, and improve the mechanical properties of cast iron, such as strength, toughness and wear resistance. Sex etc. At the same time, low-carbon ferrosilicon helps reduce the whitening tendency of cast iron, reduces the probability of defects such as cracks and shrinkage holes in castings, and improves the quality and yield of castings.
High carbon ferrosilicon: In the production of some cast iron parts with high strength and high hardness requirements, adding an appropriate amount of high carbon ferrosilicon can further improve the hardness and strength of the cast iron. However, care must be taken to control the amount of addition to avoid making the cast iron too hard and brittle, which may affect the quality of the cast iron. Its processing performance and usage performance.
Other areas
Low carbon ferrosilicon: Due to its low carbon content, it is more suitable for the production of certain alloy materials or metal products that have strict requirements on carbon content. For example, when manufacturing parts for some precision instruments, electronic components, etc., the use of low-carbon ferrosilicon can better ensure the performance and quality of the product and avoid affecting the electrical conductivity, thermal conductivity and other physical properties of the material due to excessive carbon content.
High carbon ferrosilicon: can be used as a reducing agent or carburizing agent in some chemical reactions. Its higher carbon content can be used to achieve chemical reactions such as carburizing or reduction in specific chemical processes to adjust product composition or performance. purpose.
Core Selection Principles
Performance Priority: Low-carbon ferrosilicon (C≤0.5%) is selected for electrical silicon steel, high-end alloy structural steel, and precision casting;
Cost and Wear Resistance Requirements: High-carbon ferrosilicon (C1.0%-1.5%) is selected for wear-resistant steel, tool steel, and ordinary wear-resistant castings;
