{"id":28919,"date":"2021-01-27T20:26:21","date_gmt":"2021-01-27T20:26:21","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=28919"},"modified":"2023-08-15T08:29:10","modified_gmt":"2023-08-15T08:29:10","slug":"pig-iron-crude-iron","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-engineering\/metals-what-are-metals\/steels-properties-of-steels\/pig-iron-crude-iron\/","title":{"rendered":"Pig Iron \u2013 Crude Iron"},"content":{"rendered":"
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In general, pig iron<\/strong> is an intermediate product of the iron industry. Pig iron<\/strong>, also known as crude iron<\/strong>, is produced by the blast furnace process and contains up to 4\u20135% carbon, with small amounts of other impurities like sulfur, magnesium, phosphorus, and manganese. Pig iron is supplied in various ingot sizes and weights, ranging from 3 kg to more than 50 kg. Pig iron is not a saleable product but an intermediate step in producing cast iron and steel. The reduction of contaminants in pig iron that negatively affect material properties, such as sulfur and phosphorus, yields cast iron containing 2\u20134% carbon, 1\u20136% silicon, and small amounts of manganese.<\/p>\n

\"pig<\/a><\/p>\n

Properties of Pig Iron<\/h2>\n
\"Pig<\/a>
Pig iron is supplied in various ingot sizes and weights, ranging from 3 kg to more than 50 kg. Pig iron is not a saleable product but an intermediate step in producing cast iron and steel.<\/figcaption><\/figure>\n

Material properties<\/strong> are intensive properties<\/strong>, which means they are independent of the amount<\/strong> of mass and may vary from place to place within the system at any moment. Materials science involves studying materials\u2019 structure and relating them to their properties (mechanical, electrical, etc.). Once materials scientist knows about this structure-property correlation, they can then go on to study the relative performance of a material in a given application. The major determinants of the structure of a material and thus of its properties are its constituent chemical elements and how it has been processed into its final form.<\/p>\n

Mechanical Properties of Pig Iron<\/h3>\n

Materials are frequently chosen for various applications because they have desirable combinations of mechanical characteristics. For structural applications, material properties are crucial, and engineers must consider them.<\/p>\n

Strength of Pig Iron<\/h3>\n

In the mechanics of materials, the strength of a material<\/strong><\/a> is its ability to withstand an applied load without failure or plastic deformation. The strength\u00a0of materials<\/strong> considers the relationship between the external loads<\/strong> applied to a material and the resulting deformation<\/strong> or change in material dimensions. The strength\u00a0of a material<\/strong> is its ability to withstand this applied load without failure or plastic deformation.<\/p>\n

Ultimate Tensile Strength<\/h3>\n

The ultimate tensile strength of pig iron <\/strong>varies greatly and depends on the form the carbon takes in the alloy. The high level of carbon makes it relatively weak and brittle. Reducing the amount of carbon to 0.002\u20132.1% by mass produces steel, which may be up to 1000 times harder than pure iron.<\/p>\n

\"Yield<\/a>The ultimate tensile strength<\/strong><\/a> is the maximum on the engineering stress-strain curve<\/a>. This corresponds to the maximum stress<\/strong> sustained by a structure in tension. Ultimate tensile strength is often shortened to \u201ctensile strength\u201d or \u201cthe ultimate.\u201d If this stress is applied and maintained, a fracture will result. Often, this value is significantly more than the yield stress (as much as 50 to 60 percent more than the yield for some types of metals). When a ductile material reaches its ultimate strength, it experiences necking where the cross-sectional area reduces locally. The stress-strain curve contains no higher stress than the ultimate strength. Even though deformations can continue to increase, the stress usually decreases after achieving the ultimate strength. It is an intensive property; therefore, its value does not depend on the size of the test specimen. However, it depends on other factors, such as the preparation of the specimen, the presence or otherwise of surface defects, and the temperature<\/strong> of the test environment and material. Ultimate tensile strengths<\/strong> vary from 50 MPa for aluminum to as high as 3000 MPa for very high-strength steel.<\/p>\n

Yield Strength<\/h3>\n

The yield strength of pig iron <\/strong>varies greatly and depends on the form the carbon takes in the alloy.<\/p>\n

The yield point<\/strong><\/a> is the point on a stress-strain curve<\/a> that indicates the limit of elastic behavior and the beginning plastic behavior. Yield strength<\/strong> or yield stress is the material property defined as the stress at which a material begins to deform plastically. In contrast, the yield point is where nonlinear (elastic + plastic) deformation begins. Before the yield point, the material will deform elastically and return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible. Some steels and other materials exhibit a behavior termed a yield point phenomenon. Yield strengths vary from 35 MPa for low-strength aluminum to greater than 1400 MPa for high-strength steel.<\/p>\n

Young\u2019s Modulus of Elasticity<\/h3>\n

Young\u2019s modulus of elasticity of pig iron varies greatly and depends on the carbon\u2019s form in the alloy.<\/p>\n

Young\u2019s modulus of elasticity<\/a> is the elastic modulus for tensile and compressive stress in the linear elasticity regime of a uniaxial deformation and is usually assessed by tensile tests. Up to limiting stress, a body will be able to recover its dimensions on the removal of the load. The applied stresses cause the atoms in a crystal to move from their equilibrium position, and all the atoms<\/a> are displaced the same amount and maintain their relative geometry. When the stresses are removed, all the atoms return to their original positions, and no permanent deformation occurs. According to Hooke\u2019s law<\/a>, <\/strong>the stress is proportional to the strain (in the elastic region), and the slope is Young\u2019s modulus<\/strong>. Young\u2019s modulus is equal to the longitudinal stress divided by the strain.<\/p>\n

\"\"<\/a><\/p>\n

The hardness of Pig Iron<\/h2>\n

Brinell hardness of pig iron varies greatly and depends on the form the carbon takes in the alloy.<\/p>\n

\"Brinell<\/a>In materials science, hardness<\/strong><\/a> is the ability to withstand surface indentation<\/strong> (localized plastic deformation<\/strong>) and scratching<\/strong>. Hardness<\/strong> is probably the most poorly defined material property because it may indicate resistance to scratching, abrasion, indentation, or even resistance to shaping or localized plastic deformation. Hardness is important from an engineering standpoint because resistance to wear by either friction or erosion by steam, oil, and water generally increases with hardness.<\/p>\n

Brinell hardness test<\/strong><\/a> is one of the indentation hardness tests developed for hardness testing. In Brinell tests, a hard, spherical indenter<\/strong> is forced under a specific load into the surface of the metal to be tested. The typical test uses a 10 mm (0.39 in) diameter hardened steel ball<\/strong> as an indenter with a 3,000 kgf (29.42 kN; 6,614 lbf) force. The load is maintained constant for a specified time (between 10 and 30 s). For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball<\/strong> is substituted for the steel ball.<\/p>\n

The test provides numerical results to quantify the hardness of a material, which is expressed by the Brinell hardness number<\/strong> \u2013 HB<\/strong>. The Brinell hardness number is designated by the most commonly used test standards (ASTM E10-14[2] and ISO 6506\u20131:2005) as HBW (H from hardness, B from Brinell, and W from the material of the indenter, tungsten (wolfram) carbide). In former standards, HB or HBS were used to refer to measurements made with steel indenters.<\/p>\n

The Brinell hardness number<\/strong> (HB) is the load divided by the surface area of the indentation. The diameter of the impression is measured with a microscope with a superimposed scale. The Brinell hardness number is computed from the equation:<\/p>\n

\"Brinell<\/a><\/p>\n

There are various test methods in common use (e.g., Brinell, Knoop<\/a>, Vickers<\/a>, and Rockwell<\/a>). Some tables correlate the hardness numbers from the different test methods where correlation is applicable. In all scales, a high hardness number represents a hard metal.<\/p>\n

Thermal Properties of Pig Iron \u2013 Crude Iron<\/h2>\n

Thermal properties<\/strong>\u00a0of materials refer to the response of materials to changes in their\u00a0temperature<\/a> and the application of heat<\/a>. As a solid absorbs energy<\/a> in the form of heat, its temperature rises, and its dimensions increase. But different materials react<\/strong> to the application of heat differently<\/strong>.<\/p>\n

Heat capacity<\/a>, thermal expansion<\/a>, and thermal conductivity<\/a> are often critical in solids\u2019 practical use.<\/p>\n

Melting Point of Pig Iron<\/h3>\n

Pig iron has a melting point in the range of 1420\u20131470 K, which is lower than either of its two main components and makes it the first product to be melted when carbon and iron are heated together.<\/p>\n

In general,\u00a0melting<\/strong>\u00a0is a\u00a0phase change<\/strong>\u00a0of a substance from the solid to the liquid phase. The\u00a0melting point<\/strong><\/a>\u00a0of a substance is the temperature at which this phase change occurs. The\u00a0melting point\u00a0<\/strong>also defines a condition where the solid and liquid can exist in equilibrium.<\/p>\n

Boiling Point of Pig Iron<\/h3>\n

Pig iron is a multi-element substance, principally of iron, with additions of carbon and impurities. The carbon is mostly in the form of carbides of the alloy metals, and the carbides will have higher boiling temperatures than the metal matrix. The boiling point of iron (not pig iron) is 2860\u00b0C, so the boiling point of pig iron is close to this value.<\/p>\n

In general,\u00a0boiling<\/strong>\u00a0is a\u00a0phase change<\/strong>\u00a0of a substance from the liquid to the gas phase. The\u00a0boiling point<\/strong>\u00a0of a substance is the temperature at which this phase change (boiling or vaporization) occurs.<\/p>\n

Thermal Conductivity of Pig Iron<\/h3>\n

Pig iron is a multi-element substance, principally of iron, with additions of carbon and impurities. The carbon is mostly in the form of carbides of the alloy metals. The thermal conductivity of iron (not pig iron) is 80 W\/(m. K).<\/p>\n

The heat transfer characteristics of solid material are measured by a property called the thermal conductivity<\/strong><\/a>, k (or \u03bb), measured in\u00a0W\/m.K<\/strong>. It measures a substance\u2019s ability to transfer heat through a material by conduction<\/a>. Note that\u00a0Fourier\u2019s law<\/strong><\/a> applies to all matter, regardless of its state (solid, liquid, or gas). Therefore, it is also defined for liquids and gases.<\/p>\n

The\u00a0thermal conductivity<\/strong><\/a> of most liquids and solids varies with temperature, and for vapors, it also depends upon pressure. In general:<\/p>\n

\"thermal<\/a><\/p>\n

Most materials are nearly homogeneous. Therefore we can usually write k = k (T)<\/strong>. Similar definitions are associated with thermal conductivities in the y- and z-directions (ky, kz). However, for an isotropic material, the thermal conductivity is independent of the transfer direction, kx = ky = kz = k.<\/p>\n<\/div><\/div>\n

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<\/span>References:<\/div>
Materials Science:\n

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
\nU.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
\nWilliam D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
\nEberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
\nGaskell, David R. (1995). Introduction to the Thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
\nGonz\u00e1lez-Vi\u00f1as, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
\nAshby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing, and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
\nJ. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.
\n<\/p><\/div><\/div><\/div>