What Is The Difference Between Ferrosilicon 75 And Ferrosilicon 72?
Mar 13, 2026
What is the difference between 75 ferrosilicon and 72 ferrosilicon?
75-A ferrosilicon refers to FeSiAl1.5-A (commonly known as 75A or 75 ferrosilicon), with the following specific composition range: Si≥75%, Al≥1.5%, Ca≤0.06%, Mg≤0.05%, Mn≤0.25%, P≤0.04%, Al+Si≤1.7%, Ti≤0.10%.
75-B ferrosilicon, also known as 72 ferrosilicon, has the following physical properties: silicon content≥72.0%, carbon content≤0.08%, phosphorus content≤0.05%, copper content≤0.10%, titanium content≤0.10%, manganese content≤0.20%, iron content≤1.00%, impurity content≤1.00%, and a natural bulk density of approximately 4.2 g/cm³.
1) 75 ferrosilicon and 72 ferrosilicon are two different grades of ferrosilicon, mainly differing in their silicon content.
75% ferrosilicon has a silicon content between 74-80%. It is a hard 75% ferrosilicon and is commonly used as a deoxidizer in the steelmaking industry.
72% ferrosilicon has a silicon content between 72-80%. It is a soft 75% ferrosilicon and is also widely used in aluminum plants, similarly as a deoxidizer in the steelmaking industry.
2) Uses of 75% and 72% ferrosilicon are as follows:
The main uses of 75% ferrosilicon are as a deoxidizer and alloying agent in the steelmaking industry, and as an inoculant and spheroidizing agent in the cast iron industry.
Specifically, 75% ferrosilicon can effectively remove oxygen from molten steel, improving the purity and quality of the steel. It can also be used as an alloying element to improve the properties of steel.
In addition, 75% ferrosilicon is used as a reducing agent in ferroalloy production, and has other applications.
72% ferrosilicon is primarily used as an alloying additive, widely applied in low-alloy structural steel, spring steel, bearing steel, heat-resistant steel, and electrical silicon steel. It is also used as an inoculant in the manufacture of ductile iron and malleable cast iron.
Additionally, it can be used as a reducing agent in ferroalloy production and the chemical industry.
3) 75% ferrosilicon is mainly used in the following scenarios:
Steel industry: 75% ferrosilicon is an indispensable deoxidizer in the steelmaking industry, ensuring steel quality while reducing phosphorus and sulfur content.
Foundry industry: Adding an appropriate amount of 75% ferrosilicon to molten iron can prevent iron from forming carbides and promote graphite precipitation and spheroidization, acting as an inoculant and spheroidizing agent.
72% ferrosilicon is used in the following situations:
In steelmaking, when smelting medium-carbon steel, ferrosilicon needs to be added to the molten steel to effectively deoxidize it and also as an alloying agent to improve the steel's properties.
In casting production, ferrosilicon can be added as an inoculant when casting low-phosphorus, low-sulfur cast iron parts. This effectively promotes graphite precipitation and spheroidization, improving the properties of the cast iron.
Ferrosilicon can also be used as a reducing agent in the ferroalloy industry for the production of low-carbon ferroalloys.
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