Bulk Ferroalloys

Bulk Ferroalloys  Ferroalloys are a group of materials which are alloys of iron that contain a high percentage of one or more non ferrous metals as alloying elements. These alloys are used for the addition of these other elements into liquid metal. They are normally used as addition agents. More than 85 % of ferroalloys produced are used primarily in the manufacture of steel. Ferroalloys are used as master alloys in steel making, alloying of steels, for the production of stainless steels, and in iron or steel foundries. Ferroalloys are used in steel making for deoxidation as well as for the introduction of alloying elements. They are the most economical way for introducing alloying element into the steel. Ferroalloys impart distinctive qualities to steels and cast irons. The effect on the qualities of steels and cast irons largely depends more or less on the following influences. A change in the chemical composition The removal or the tying up of harmful impurities such as oxygen, nitrogen, sulphur or hydrogen A change in the nature of the solidification, for example, upon inoculation. Ferroalloys are also added in steel production for grain size control as well as for improvement in the mechanical properties of steel. Depending upon the process of steelmaking and the type of steel being made, the requirement of different ferroalloys varies widely. The addition of ferroalloys to steel increases its resistance to corrosion and oxidation, improves its hardenability, tensile strength at high temperature, wear and abrasion resistance with added carbon and increases other desired properties in the steel such as creep strength etc. Ferroalloys are vital inputs for producing all types of steel. They are used as raw material in the production of alloys steel and stainless steel. Ferroalloys are usually classified into two...

Ferroalloys

Ferroalloys Ferroalloys are alloys of iron with a high percentage of one or more of other elements. Ferroalloys industry is very closely related to iron and steel industry since ferroalloys are used in steel making, alloying of steels and in iron or steel foundries. In the production of steel, ferro alloys are used for deoxidation of steels as well as for introduction of the alloying elements in the steel. Ferroalloys impart distinctive qualities to steel and cast iron.  Depending upon the process of steel making and the product quality envisaged, the requirement of ferroalloys varies widely. Ferroalloys are usually classified into two groups namely (i) Bulk ferroalloys and (ii) Noble or special ferroalloys. More than 85 % of ferroalloys produced are used in the steel industry. Bulk ferroalloys Bulk ferroalloys consist of principal alloys namely ferro manganese (Fe-Mn), silico manganese (Si-Mn), ferro chrome/charge chrome (Fe-Cr) and ferro silicon (Fe-Si). These are shown in Fig 1. Fig 1 Bulk ferroalloys Ferro manganese – Fe – Mn is a ferroalloy with high content of manganese (Mn). It is produced by heating a mixture of the oxides of MnO2 and Fe203 with carbon usually as coal and coke, in either a blast furnace or a submerged arc furnace. The oxides undergo carbo thermal reduction to produce Fe- Mn. It is produced as three types of products namely (i) standard high carbon (C) Fe-Mn, (ii) medium carbon Fe-Mn and (iii) low carbon Fe- Mn. High carbon Fe – Mn has manganese in the range of 72 % to 82 %, C in the range of 6 % to 8 % and silicon (Si) in the range of around 1.5 %. Medium carbon Fe- Mn has manganese in the range of 74 % to 82 %, C in the...