Ferroalloy is one of the important raw materials indispensable in the steel industry and mechanical casting industry. Its main uses: one is as a deoxidizer to remove excess oxygen in molten steel; the other is as an alloy element additive to improve the quality and performance of steel. With the continuous and rapid development of my country’s iron and steel industry, and the continuous expansion and improvement of steel varieties and quality, higher requirements are put forward for ferroalloy products. The ferroalloy industry has increasingly become a related industry and supporting project of the iron and steel industry. The main uses of ferroalloys are as follows:
(1) is used as a deoxidizer. The steelmaking process is a process of decarburizing molten iron and removing harmful impurities such as phosphorus and sulfur by blowing oxygen or adding oxidants. The progress of this process, although the pig iron is made into steel, the content of [O] in the molten steel has increased. [O] generally exists in the form of [FeO] in molten steel. If the excess oxygen remaining in the steel is not removed, a qualified steel billet cannot be cast, and steel with good mechanical properties cannot be obtained. For this reason, it is necessary to add some elements that have stronger binding force to oxygen than iron, and their oxides are easy to remove the elements that enter the slag from the molten steel, thereby removing [O] in the molten steel. This process is called deoxidation. The alloy used for deoxidation is called deoxidizer. The binding strength of various elements in molten steel to oxygen, that is, the deoxidizing ability, from weak to strong is as follows: chromium, manganese, carbon, silicon, vanadium, titanium, boron, aluminum, zirconium, calcium. Therefore, iron alloys composed of silicon, manganese, aluminum, and calcium are commonly used for steelmaking deoxidation.
(2) is used as an alloying agent. Alloy steel has different properties because it contains different alloying elements. The content of alloying elements in steel is adjusted by adding iron alloys. The ferroalloy used to adjust the content of alloying elements in steel is called alloying agent. Commonly used alloying agents include iron alloys containing silicon, manganese, chromium, molybdenum, vanadium, tungsten, titanium, diamond, nickel, boron, niobium, zirconium and other elements.
(3) is used as an inoculant for casting crystal nuclei. One of the measures to improve the properties of cast iron and cast steel is to change the solidification conditions of the castings. In order to change the solidification conditions, some iron alloys are often added as crystal nuclei before casting to form the crystal grain center, so that the formed graphite becomes finely dispersed and the crystal grains are refined, thereby improving the performance of the casting.
(4) Other uses. In the metallurgical and chemical industries, ferroalloys are also more and more widely used as a medium for beneficiation, as raw materials for the preparation of certain products and ultra-pure substances (elements or compounds).