Ferroalloy is an alloy product composed of one or two metal (or non-metal) elements and iron elements. It is a very important raw material in the iron and steel industry. It is used as a deoxidizer, desulfurizer, alloy element additive, etc. In the molten iron to make the steel have certain characteristics, or a product that meets certain requirements.
Properties of iron alloys
Iron alloys generally have a high melting point, making it difficult to smelt pure metals. If they are combined with iron, they are easier to recover and smelt. Ferroalloys are used in iron and steel smelting. The iron contained in it is not only harmless, but also beneficial because it is easy to melt in molten steel. Therefore, the deoxidation and addition of alloys in the steelmaking production process are mostly added in the form of ferroalloys. Ferroalloys are generally too brittle to be used as metal composites.
Classification of ferroalloys
1. According to the classification of main iron alloys, there are mainly series of iron alloys such as silicon, manganese, chromium, vanadium, titanium, tungsten, and molybdenum.
2. According to the classification of ferroalloys, there are high carbon, medium carbon, low carbon, micro carbon, ultra micro carbon and other varieties.
3. Multiferroic alloys containing two or more alloy elements, the main varieties are silicon-aluminum alloy, silicon-calcium alloy, manganese-silicon-aluminum alloy, silicon-calcium-aluminum alloy, silicon-barium-calcium alloy, etc.
4. Classification by production method: There are blast furnace ferroalloys, electric furnace ferroalloys, out-of-furnace (metal thermal) ferroalloys, vacuum solid-state reduction ferroalloys, electrolytic ferroalloys, and special ferroalloys such as oxide briquettes and heating ferroalloys.
Uses of ferroalloys
1. As a deoxidizer, the binding strength of various elements in molten steel to oxygen, that is, the deoxidation ability, is as follows from weak to strong: chromium, manganese, carbon, silicon, vanadium, titanium, boron, aluminum, zirconium, calcium. Generally, iron alloys composed of silicon, manganese, aluminum and calcium are commonly used for deoxidation in steelmaking.
2. Used as an alloying agent, used to adjust the chemical composition of steel to alloy steel elements or alloys called alloying agents, commonly used alloying elements are silicon, manganese, chromium, molybdenum, vanadium, titanium, tungsten, cobalt, boron, niobium Wait.
3. Used as a casting crystal nuclei inoculant. In order to change the solidification conditions, some iron alloys are usually added as crystal nuclei before pouring to form a grain center, so that the formed graphite becomes fine and dispersed, and the grains are refined, thereby improving the casting. performance.
4. As a reducing agent, ferrosilicon can be used as a reducing agent for producing ferromolybdenum, ferrovanadium and other ferroalloys, silicon-chromium alloy and silicon-manganese alloy can be used as reducing agents for refining medium-low carbon ferrochromium and medium-low carbon ferromanganese respectively.
5. Other uses. In the non-ferrous metallurgy and chemical industries, ferroalloys are also being used more and more widely.