In the process of the development of the ferro silicon industry, some conventional names have gradually formed. In the early days, people classified and named FeSi according to the approximate range of silicon content in ferrosilicon. The silicon content of ferrosilicon 72 is about 72%, which is similar to ferrosilicon alloy with a silicon content of about 75% in some properties and uses. For the convenience of distinction and classification, FeSi 72 is called 75B, and the silicon content is higher and closer to 75% is called FerroSilicon 75A.

72 Ferrosilicon is also referred to as FeSi 75B because, within the ferrosilicon grade system, they are both sub-grades of the 75 series and have similar silicon contents.

FeSi 75 generally refers to ferrosilicon with a silicon content of 74% or greater and can be divided into grades such as 75A, 75B, and 75C. The silicon content of 75B ferrosilicon generally ranges from 73% to 75%. Because its silicon content is close to 72% and its performance and uses are similar to those of ferrosilicon 72% in practical applications, many in the industry refer to fesi 72 as fesi 75B. Furthermore, according to the national standard GB/T 2272-2020, ferrosilicon alloy with the grade PG FeSi72Al2.5 is commonly referred to as 72#, also known as 75B.

FerroSilicon 72 (75B)

chemical composition

Grade	Chemical Composition(mass fraction)%
	Si	Al	Ca	Mn	Cr	P	S	C
	≥	≤
FeSi90Al1.5	87.0~95.0	1.5	1.5	0.4	0.2	0.04	0.02	0.2
FeSi9oAl3.0	87.0~95.0	3	1.5	0.4	0.2	0.04	0.02	0.2
FeSi75Al0.5-A	74.0~80.0	0.5	1	0.4	I0.3	0.035	0.02	0.1
FeSi75Al0.5-B	72.0~80.0	0.5	1	0.5	0.5	0.04	0.02	0.2
FeSi75Al1.0-A	74.0~80.0	1	1	0.4	0.3	0.035	0.02	0.1
FeSi75Al1.0-B	72.0~80.0	1	1	0.5	0.5	0.04	0.02	0.2
FeSi75Al1.5-A	74.0-80.0	1.5	1	0.4	0.3	0.035	0.02	0.1
FeSi75Al1.5-B	72.0~80.0	1.5	1	0.5	0.5	0.04	0.02	0.2
FeSi75Al2.0-A	74.0~80.0	2	1	0.4	0.3	0.035	0.02	0.1
FeSi75Al2.0-B	72.0~80.0	2		0.5	0.5	0.04	0.02	0.2
FeSi75-A	74.0~80.0			0.4	0.3	0.035	0.02	0.1
FeSi75-B	72.0~80.0			0.5	0.5	0.04	0.02	0.2
FeSi65	65.0~72.0			0.6	0.5	0.04	0.02

Product Uses

Deoxidizer:

In the steelmaking process, ferrosilicon 72 is a commonly used deoxidizer. A certain amount of oxygen in molten steel will affect the quality and performance of steel. After adding ferrosilicon 75B, silicon has a strong affinity with oxygen and can quickly react with oxygen in molten steel to generate stable oxides such as silicon dioxide, thereby removing oxygen in molten steel, improving the quality of steel, and improving the strength, toughness, corrosion resistance and other properties of steel.

Alloy additives:

FeSi 75B can be used as an alloying element to adjust the chemical composition of steel. Silicon can improve the strength, hardness and wear resistance of steel, increase the magnetic permeability of steel, and reduce hysteresis loss. Therefore, when producing various alloy steels, stainless steels, and heat-resistant steels, FeSi 72 is an indispensable alloying additive that can make steel meet different usage requirements and performance indicators.

Inoculant:

In cast iron production, It is an important inoculant. It can promote graphitization, improve the morphology and distribution of graphite, improve the mechanical properties of cast iron, especially toughness and ductility, reduce the tendency of white cast iron, make the organization of castings more uniform, and improve the quality and reliability of castings.

Spheroidizer and inoculant:

In the production of ductile iron, Ferro silicon 75B is often used in combination with elements such as magnesium as a spheroidizer, which can spheroidize graphite in cast iron and significantly improve the mechanical properties of cast iron. At the same time, it is also an effective inoculant, which can increase the number of graphite cores during the solidification of molten iron, refine graphite, and improve the comprehensive performance of castings. It is widely used in the manufacture of various mechanical parts, automotive parts, pipe fittings and other casting products.

Adjusting composition:

When casting non-ferrous alloys, such as aluminum alloys and copper alloys, ferro silicon 72% can be used to adjust the silicon content in the alloy to improve the casting performance, mechanical properties and corrosion resistance of the alloy.

Chemical industry:

It can be used as a reducing agent to produce other silicides, such as magnesium silicide and calcium silicide. These silicides have important applications in the chemical industry and can be used as catalysts for organic synthesis and raw materials for electronic materials. In addition, 72 ferrosilicon can also be used to produce silane gas, which is an important chemical raw material and is widely used in the semiconductor industry, solar cell manufacturing and other fields.

Nonferrous metal industry:

72% Ferrosilicon also has certain applications in the production and processing of some nonferrous metals.

Powder metallurgy industry:

Ferrosilicon 75B powder can be used as an important additive in the production of powder metallurgy products. It can improve the forming and sintering properties of the powder, and improve the strength and hardness of powder metallurgy products. It is widely used in the manufacture of various mechanical parts, automotive parts, tools and other powder metallurgy products.

FerroSilicon 72 (75B)