Ferro-Manganese

Ferro-Manganese Ferro-manganese (Fe-Mn) is a metallic ferro alloy which is added usually along with ferro-silicon (Fe-Si) as ladle addition during steelmaking. It is a ferroalloy composed principally of manganese (Mn) and iron (Fe), and normally contains much smaller proportions of minor elements, such as carbon (C), phosphorus (P), and sulphur (S). Fe-Mn is an important additive used as a deoxidizer in the production of steel. It is a master alloy of Fe and Mn with a minimum Mn content of 65 %, and maximum Mn content of 95 %. There are two families of Mn alloys. One is called Fe-Mn while the other is known as silico-manganese (Si-Mn). Around 93 % of all the Mn produced is in the form of Mn ferroalloys consists of the Fe-Mn grades and the Si-Mn grades. Mn plays an important role in the manufacturing of steel as deoxidizing, desulphurizing, and alloying agent. It is a mild deoxidizer than silicon (Si) but enhances the effectiveness of the latter due to the formation of stable manganese silicates and aluminates. Mn is used as an alloying element in almost all types of steel. Of particular interest is its modifying effect on the iron-carbon (Fe-C) system by increasing the hardenability of the steel. Fe-Mn is produced in a number of grades and sizes and is consumed in bulk form primarily in the production of steel as a source of Mn, although some Fe-Mn is also used as an alloying agent in the production of iron castings. Mn, which is intentionally present in nearly all steels, is used as a steel desulphurizer and deoxidizer. Mn improves the tensile strength, workability, toughness, hardness and resistance to abrasion. By removing S from steel, Mn prevents the steel from becoming brittle during the hot rolling process....

Silico- Manganese

Silico- Manganese Silico-manganese (Si-Mn) is a metallic ferro alloy which is being used to add both silicon (Si) and manganese (Mn) as ladle addition during steelmaking. Because of its lower carbon (C) content, it is a preferred ladle addition material during making of low carbon steels. Si-Mn is a ferroalloy composed principally of Mn, Si, and Fe (iron), and normally contains much smaller proportions of minor elements, such as C, phosphorus (P), and sulphur (S). The ferroalloy is also sometimes referred to as ferro-silicon-manganese. Both Mn and Si play an important role in the manufacturing of steel as deoxidizing, desulphurizing, and alloying agents. Si is the primary and more powerful deoxidizer. Mn is a milder deoxidizer than Si but enhances the effectiveness of the latter due to the formation of stable manganese silicates and aluminates. It also serves as desulphurizer. Mn is used as an alloying element in almost all types of steel. Of particular interest is its modifying effect on the iron-carbon (Fe-C) system by increasing the hardenability of the steel. There are two families of Mn alloys one is called Si-Mn while the other is known as ferro-manganese (Fe-Mn). Si-Mn adds additional silicon in liquid steel which is a stronger deoxidizer and which also helps to improve some mechanical properties of steel. In each family, content of C can be controlled and lowered when producing low C grades. Around 93 % of all the Mn produced is in the form of Mn ferroalloys consists of the Fe-Mn grades and the Si-Mn grades. The Fe-Mn grades are high carbon (HC), medium carbon (MC), low-carbon (LC) and very low carbon (VLC), whereas the Si-Mn grades include medium carbon (MC) and low carbon (LC). The steel industry is the only consumer of these alloys. However...

Silica and its role in the production of iron and steel...

Silica and its role in the production of iron and steel Silicon, the element, is the second most abundant element in the earth’s crust. Silica is the scientific name for a group of minerals made of silicon and oxygen. It is one of the most abundant oxide materials in the earth’s crust and is found in most mineral deposits found on the earth. It is the starting material for the production of ceramics and silicate glasses. Silica (from the Latin word ‘silex’), is an oxide of silicon. It is a compound made up of silicon and oxygen atoms and has the chemical formula SiO2. It occurs commonly in nature as sandstone, silica sand or quartzite. It is the most frequently found in nature as quartz (SiO4). It is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound in several minerals. Silica occurs in a variety of crystalline modifications and also as an under-cooled melt called quartz glass. The crystal structure of the individual SiO2 modifications can differ widely, so that distinct density changes occur during transformation. This is of great importance during heating and cooling because of the change in the volume. Silica can be a naturally occurring substance, like quartz, or it can result from human activities. It occurs in many forms. It can exist in an amorphous form (vitreous silica) or in a variety of crystalline forms. Amorphous silica is found in nature (e.g., diatomaceous earth and plants), as well as in synthetic materials. In amorphous silica, the silicon and oxygen atoms are not arranged in any particular pattern. Amorphous forms of silica have a random pattern while in crystalline silica, atoms of silicon and oxygen are arranged in a repeating, three dimensional pattern which is known as crystal lattice. Crystalline silica...

Induction Furnace Refractory Lining with Silica Ramming Mass...

Induction Furnace Refractory Lining with Silica Ramming Mass Induction furnaces are used for melting cast iron, mild steel and various alloy steels in foundries and making of steel in mini steel plants using sponge iron. Lining is the important part of induction furnace. Furnace performance is directly related to the performance of its lining. Well laid and stabilized lining results in smooth working of furnace, optimum output, and good control of the metallurgical reactions. The lining practice best suited to a particular furnace depends upon the capacity and design of the furnace, operation practice adopted during making of a heat, and furnace output. For successful and consistent performance of the lining, the important aspects are (i) use of proper grade and quality of the lining material, (ii) careful and systematic lining practice, and (iii) consistency in working conditions.  Fig 1 shows the installed refractory lining of a coreless induction furnace, Fig 1 Installed refractory lining of a coreless induction furnace The characteristics of the lining material needed for consistent lining life include (i) thermal characteristics which means that it has to withstand the stresses developed by thermal cycles during the furnace operation, (ii) chemically inert to metal being melted, (iii) structural strength under operating conditions, (iv) high erosion resistance, (v) ease of installation, (vi) reparability of the lining, (vii) ease of dismantling, and (viii) economics. As such, it is very difficult to judge the suitability of a particular lining under various conditions like operating temperature, metal being melted, the type of formed slag, and furnace capacity. Chemical inertness to the liquid metal can be achieved by using acid and neutral lining for the acidic slag and neutral or basic lining for the basic slags. Normally, the selection of refractory for the furnace lining is...

Iron Carbide

Iron Carbide Iron carbide is a high melting point, non-pyrophoric, strongly magnetic synthetic compound obtained in granular or powder form. It is composed of three atoms of Fe and one atom C and its chemical formula is Fe3C. The commercial iron carbide consists of around 90 % total iron and around 6 % to 6.5 % of total carbon. The primary use of the product is as a metallic charge during steelmaking for substitution of hot metal, direct reduced iron, or steel scrap. Iron carbide is an intermetallic compound of iron and carbon. It is, more precisely, intermediate transition metal carbide. Its stoichiometric composition consists of 6.67 % carbon and 93.3 % iron (Fe) by weight. It has an orthorhombic crystal structure (Fig 1). It is a hard, brittle material and normally classified as a ceramic in its pure form. It is a frequently found and important constituent in ferrous metallurgy. While iron carbide is present in most steels and cast irons, it is produced as a raw material by the iron carbide process, which belongs to the family of alternative ironmaking technologies. Fig 1 Crystal of iron carbide Iron carbide is a premium quality feed for steelmaking in electric arc furnaces and basic oxygen furnaces. It is available as dark gray granules or powder. It offers matchless metallurgical advantages and outstanding cost savings. It has a density of 7.64 kg/cu m and is thus slightly denser than the liquid iron, which has a density of 6.98 kg/cu m. The iron carbide is composed of three atoms of Fe and one atom C and is also known as cementite. Cementite is an intermetallic compound which is hard, brittle, and metastable because it tends to decompose in ferrite (or austenite) and graphite according to the reaction Fe3C = 3 Fe + C. In fact, this transformation is not...

Tensile Testing of Steel...

Tensile Testing of Steel Sample of steel is subjected to a wide variety of mechanical tests to measure their strength, elastic constants, and other material properties as well as their performance under a variety of actual use conditions and environments. Tensile test is one of them. Other tests are hardness test, impact test, fatigue test, and fracture test. These mechanical tests are used to measure how a sample of steel withstands an applied mechanical force. The results of such tests are used for two primary purposes namely (i) engineering design (e.g. failure theories based on strength, or deflections based on elastic constants and component geometry), and (ii) quality control either by the producer of steel to verify the process or by the end user to confirm the material specifications. Uniaxial tensile test is known as a basic and universal engineering test to achieve material parameters such as ultimate tensile strength (UTS), yield strength (YS), % elongation, % area of reduction and young’s modulus. Tensile testing is done for many reasons. The results of tensile tests are used in selecting materials for engineering applications. Tensile properties are often included in material specifications to ensure quality. Tensile properties are also normally measured during development of new materials and processes, so that different materials and processes can be compared. Also, tensile properties are generally used to predict the behaviour of a material under forms of loading other than uniaxial tension. Safely withstanding the expected maximum load without permanent deformation (or to stay within the specified deflection) is a basic requirement for a steel product. The ‘resistance’ against the load is a function of the cross-section and the mechanical properties (or in other words the ‘strength’) of the steel material. Tensile testing is done to determine the mechanical...