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Red-short
Red-short, hot-short refers to brittleness of steels at red-hot temperatures. It is often caused by high sulfur levels, in which case it is also known as sulfur embrittlement. Description Iron or steel, when heated to above 900 °F (460 °C), glows with a red color. The color of heated iron changes predictably (due to black-body radiation) from dull red through orange and yellow to white, and can be a useful indicator of its temperature. Good quality iron or steel at and above this temperature becomes increasingly malleable and plastic. Iron or steel having too much sulfur, on the other hand, becomes crumbly and brittle. This is due to the sulfur forming iron sulfide/iron mixtures in the grain boundaries of the metal which have a lower melting point than the steel.Deev et al. (May–June 1982)"Role of iron sulfide in the formation of cracks in weld joints" ''Materials Science'', Vol. 18, No. 3, pp. 109–112. When the steel is heated up and worked, the mechanical energy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steel
Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant typically need an additional 11% chromium. Because of its high tensile strength and low cost, steel is used in buildings, infrastructure, tools, ships, trains, cars, machines, electrical appliances, weapons, and rockets. Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic. The interaction of the allotropes of iron with the alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile, or soft and easily formed. In steel, small amounts of carbon, other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Black-body Radiation
Black-body radiation is the thermal electromagnetic radiation within, or surrounding, a body in thermodynamic equilibrium with its environment, emitted by a black body (an idealized opaque, non-reflective body). It has a specific, continuous spectrum of wavelengths, inversely related to intensity, that depend only on the body's temperature, which is assumed, for the sake of calculations and theory, to be uniform and constant., Chapter 13. A perfectly insulated enclosure which is in thermal equilibrium internally contains black-body radiation, and will emit it through a hole made in its wall, provided the hole is small enough to have a negligible effect upon the equilibrium. The thermal radiation spontaneously emitted by many ordinary objects can be approximated as black-body radiation. Of particular importance, although planets and stars (including the Earth and Sun) are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is sti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ductility
Ductility is a mechanical property commonly described as a material's amenability to drawing (e.g. into wire). In materials science, ductility is defined by the degree to which a material can sustain plastic deformation under tensile stress before failure. Ductility is an important consideration in engineering and manufacturing. It defines a material's suitability for certain manufacturing operations (such as cold working) and its capacity to absorb mechanical overload.. Some metals that are generally described as ductile include gold and copper. However, not all metals experience ductile failure as some can be characterized with brittle failure like cast iron. Polymers generally can be viewed as ductile materials as they typically allow for plastic deformation. Malleability, a similar mechanical property, is characterized by a material's ability to deform plastically without failure under compressive stress. Historically, materials were considered malleable if they were am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Sulfide
Iron sulfide or Iron sulphide can refer to range of chemical compounds composed of iron and sulfur. Minerals By increasing order of stability: * Iron(II) sulfide, FeS * Greigite, Fe3S4 (cubic) * Pyrrhotite, Fe1−xS (where x = 0 to 0.2) (monoclinic or hexagonal) * Troilite, FeS, the endmember of pyrrhotite (hexagonal) * Mackinawite, Fe1+xS (where x = 0 to 0.1) (tetragonal) * Marcasite, orthorhombic FeS2 * Pyrite, cubic FeS2 (fool's gold) * Arsenopyrite (''mispickel''), FeAsS, or Fe(As-S), Fe(III) mixed arseno-sulfide (monoclinic) Synthetic * Iron(III) sulfide, Fe2S3 * Iron-sulfur clusters, includes both synthetic and biological Biological * Iron–sulfur protein Iron–sulfur proteins (or iron–sulphur proteins in British spelling) are proteins characterized by the presence of iron–sulfur clusters containing sulfide-linked di-, tri-, and tetrairon centers in variable oxidation states. Iron–sulfur cl ... {{DEFAULTSORT:Iron Sulfide Iron compounds Iron minerals Sulfur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese
Manganese is a chemical element with the symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese is a transition metal with a multifaceted array of industrial alloy uses, particularly in stainless steels. It improves strength, workability, and resistance to wear. Manganese oxide is used as an oxidising agent; as a rubber additive; and in glass making, fertilisers, and ceramics. Manganese sulfate can be used as a fungicide. Manganese is also an essential human dietary element, important in macronutrient metabolism, bone formation, and free radical defense systems. It is a critical component in dozens of proteins and enzymes. It is found mostly in the bones, but also the liver, kidneys, and brain. In the human brain, the manganese is bound to manganese metalloproteins, most notably glutamine synthetase in astrocytes. Manganese was first isolated in 1774. It is familiar in the laboratory in the form of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese Sulfide
Manganese(II) sulfide is a chemical compound of manganese and sulfur. It occurs in nature as the mineral alabandite (isometric), rambergite (hexagonal), and recently found browneite (isometric, with sphalerite-type structure, extremely rare, known only from a meteorite).Mindat, http://www.mindat.org/min-42751.html Synthesis Manganese(II) sulfide can be prepared by reacting a manganese(II) salt (such as manganese(II) chloride) with ammonium sulfide: : + → 2 + MnS Properties The crystal structure of manganese(II) sulfide is similar to that of sodium chloride. The pink color of MnS likely results from poor coupling between the lowest energy unoccupied Mn orbitals, resulting in discrete states rather than a delocalized band. Thus the lowest energy band-to-band electronic transition requires very high energy (ultraviolet) photons. See also *Alabandite, cubic MnS. * Manganese disulfide, MnS2, also known as Manganese(IV) Sulfide * Manganese(II) sulfate, MnSO4 *Rambergite Rambe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
