The role of ferrosilicon and ferromanganese in steelmaking

Ferrosilicon and manganese-silicon are the most widely used ferroalloys in the steelmaking process. They are mainly used as deoxidizers and alloying agents in steelmaking to eliminate excess oxygen and sulfur in molten steel and improve the quality and performance of steel. In addition to being used for steelmaking, ferrosilicon is also used for smelting magnesium metal.

used as a deoxidizer

The molten iron is decarburized by blowing oxygen or adding an oxidant to remove harmful impurities such as phosphorus and sulfur. During the process of making pig iron into steel, the oxygen content in the molten steel gradually increases and exists in the molten steel in the form of FeO. If the oxygen in the steel is not removed, the mechanical properties of the cast billet will be poor.

It is necessary to add some elements that combine with oxygen and are easy to exclude from the molten steel and enter the slag. According to the binding strength of various elements in molten steel to oxygen, the order from weak to strong is as follows: chromium, manganese, carbon, silicon, vanadium, titanium, boron, aluminum, zirconium, calcium. Therefore, ferroalloys composed of silicon, manganese, aluminum, and calcium are commonly used in steelmaking deoxidation.

Used as an alloying agent

Alloying elements can not only reduce the impurity content in steel, but also adjust the chemical composition of steel. Commonly used alloying elements include silicon, manganese, chromium, molybdenum, vanadium, titanium, tungsten, cobalt, boron, niobium, etc. Steel grades containing different alloying elements and alloying contents have different properties and uses.

used as reducing agent

Ferrosilicon can be used as a reducing agent for the production of ferromolybdenum, ferrovanadium and other ferroalloys, and silicon-chromium alloy and silicon-manganese alloy can be used as reducing agents for refining medium and low carbon ferrochromium and medium and low carbon ferromanganese respectively.

In summary, silicon can significantly improve the elasticity and magnetic permeability of steel. Manganese can reduce the brittleness of steel, improve the hot workability of steel, and increase the strength, hardness and wear resistance of steel. Manganese is an indispensable functional basic raw material for the production of high-quality steel. During the steelmaking process, it can remove impurities such as sulfur and oxygen, and improve the physical properties of steel by improving properties such as strength, hardness and wear resistance. At present, there is no other element that can replace the role of manganese in the steel production process.