![]() Thermal conductivity, along with specific heat and density, determines the thickness of the steel shell, which forms on the cold addition. Density determines whether the addition floats (ferrosilicon), sinks (ferromanganese) or get entrained within the liquid bath (ferrochromium). Melting point is the primary factor for the rate of dissolution of the ferroalloys, while other important properties include density, thermal conductivity, specific heat, and enthalpy of mixing. Several physical and chemical properties of ferroalloys affect the dissolution of the ferroalloy in the liquid steel. Convective heat transfer is a function of bath stirring and superheat and it governs shell melting. Heat transferred from the liquid steel re-melts this shell back to the original ferroalloy surface. Upon addition, a steel shell is frozen on the surface of the ferroalloy. However, there is a trend towards making more additions during secondary steelmaking processes or even at the tundish using specialty wire products.ĭuring the addition of the ferroalloy to the liquid steel bath, it is necessary to immerse the ferroalloy into the liquid steel. In good steelmaking practice, ferroalloys are not generally added to the melting furnace and around 60 % to 90 % of ferroalloy additions are made to the ladle during tapping of the liquid steel and balance is added during secondary steelmaking processes. Some of the alloys such as silico-manganese which contains iron only in very small percentage are also generally classified as bulk ferroalloys. They are namely ferro molybdenum (Fe-Mo), ferro vanadium (Fe-V), ferro tungsten (Fe-W), ferro titanium (Fe-Ti) and ferro niobium (Fe-Nb). These ferroalloys are of high value and consumed in low volumes. Noble ferroalloys are the vital inputs for the production of special and alloy steels. Bulk ferroalloys consist of principal alloys namely ferro manganese (Fe-Mn), ferro chrome/charge chrome (Fe-Cr) and ferro silicon (Fe-Si). They have high affinity for O2 and form oxides in the form of slag.įerroalloys are usually classified into two groups namely (i) bulk ferroalloys, and (ii) noble or special ferroalloys. Ferroalloys are added to liquid steel to carry out the de-oxidation process of removal of excess oxygen (O2) from the liquid steel. ![]() They are used mainly for deoxidation and alloying of steels.įerroalloys have lower melting ranges than the pure elements and have lower density hence can be incorporated more readily in the liquid steel than the pure elements. Ferroalloys are important raw materials for the steelmaking process. They are brittle and unsuitable for direct use in fabricating of products of use. ![]() alumina, bulk ferroalloys, deoxidation, Ferro manganese, Ferro silicon, Ferroalloys, inclusion, liquid steel, noble ferroalloys, Silico manganese, slag ,įerroalloys are alloys of iron with a high percentage of one or more of other elements such as silicon (Si) and manganese (Mn) etc.Utilization Optimization of Ferroalloys during Steelmaking ![]()
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