|
Krupp Cemented Armour
Krupp armour was a type of steel naval armour used in the construction of capital ships starting shortly before the end of the nineteenth century. It was developed by Germany's Krupp Arms Works in 1893 and quickly replaced Harvey armour as the primary method of protecting naval ships, before itself being supplanted by the improved Krupp cemented armour. Original Krupp armour The initial manufacturing of Krupp armour was very similar to Harveyized armour; however, while the Harvey process generally used nickel-steel, the Krupp process added as much as 1% chromium to the alloy for additional hardness. Even though use of chromium in steels predated the use of nickel, the necessary amount of chromium complicated steel case-hardening due to its ability to crack (hence water tempering had to be replaced with slower oil-tempering). Also, while Harveyized armour was carburized by heating the steel and placing charcoal on its surface for long periods (often several weeks), Krupp armou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of The Manufacture Of Armor Plate For The United States Navy (1899) (14595554570)
History is the systematic study of the past, focusing primarily on the human past. As an academic discipline, it analyses and interprets evidence to construct narratives about what happened and explain why it happened. Some theorists categorize history as a social science, while others see it as part of the humanities or consider it a hybrid discipline. Similar debates surround the purpose of history—for example, whether its main aim is theoretical, to uncover the truth, or practical, to learn lessons from the past. In a more general sense, the term ''history'' refers not to an academic field but to the past itself, times in the past, or to individual texts about the past. Historical research relies on primary and secondary sources to reconstruct past events and validate interpretations. Source criticism is used to evaluate these sources, assessing their authenticity, content, and reliability. Historians strive to integrate the perspectives of several sources to develop a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylene
Acetylene (Chemical nomenclature, systematic name: ethyne) is a chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is unstable in its pure form and thus is usually handled as a solution. Pure acetylene is odorless, but commercial grades usually have a marked odor due to impurities such as divinyl sulfide and phosphine.Compressed Gas Association (1995Material Safety and Data Sheet – Acetylene As an alkyne, acetylene is Saturated and unsaturated compounds, unsaturated because its two carbon atoms are Chemical bond, bonded together in a triple bond. The carbon–carbon triple bond places all four atoms in the same straight line, with CCH bond angles of 180°. The triple bond in acetylene results in a high energy content that is released when acetylene is burned. Discovery Acetylene was discovered in 1836 by Edmund Davy, who identified it as a "new carburet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Special Treatment Steel
Special treatment steel (STS), also known as protective deck plate, was a type of warship armor developed by Carnegie Steel around 1910. History STS is a homogeneous Krupp-type steel developed around 1910. The development of such homogeneous steel resulted from testing which showed that face-hardened armor was less effective against high-obliquity glancing impacts. Around 1910, Carnegie Steel developed a new nickel-chrome-vanadium alloy-steel that offers improved protection over the prior nickel steel armor, though vanadium was no longer used after 1914. This alloy-steel became known as "Special Treatment Steel (STS)"; it became the U.S. Navy Bureau of Construction and Repair (later Bureau of Ships) standard form of high-percentage nickel steel used on all portions of a warship needing homogeneous direct impact protection armor. STS was used as homogeneous armor that was less than thick; homogeneous armor for gun mounts and conning towers, where the thicknesses were considera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolled Homogeneous Armour
Rolled homogeneous armour (RHA) is a type of vehicle armour made of a single steel composition hot-rolled to improve its material characteristics, as opposed to layered or cemented armour. Its first common application was in tanks. After World War II, it began to fall out of use on main battle tanks and other armoured fighting vehicles intended to see front-line combat as new anti-tank weapon technologies were developed which were capable of relatively easily penetrating rolled homogeneous armour plating even of significant thickness. Today, the term is primarily used as a unit of measurement of the protection offered by armour on a vehicle (often composed of materials that may not actually contain steel, or even contain any metals) in equivalent ''millimetres of RHA'', referring to the thickness of RHA that would provide the same protection. Typically, modern composite armour can provide the same amount of protection with much thinner and lighter construction than its protective ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spalling
Spall are fragments of a material that are broken off a larger solid body. It can be produced by a variety of mechanisms, including as a result of projectile impact, corrosion, weathering, cavitation, or excessive rolling pressure (as in a ball bearing). Spalling and spallation both describe the process of surface failure in which spall is shed. The terms ''spall'', ''spalling'', and ''spallation'' have been adopted by particle physicists; in neutron scattering instruments, neutrons are generated by bombarding a uranium (or other) target with a stream of atoms. The neutrons that are ejected from the target are known as "spall". Mechanical spalling Mechanical spalling occurs at high-stress contact points, for example, in a ball bearing. Spalling occurs in preference to brinelling, where the maximal shear stress occurs not at the surface, but just below, shearing the spall off. One of the simplest forms of mechanical spalling is plate impact, in which two waves of compres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Oil
Mineral oil is any of various colorless, odorless, light mixtures of higher alkanes from a mineral source, particularly a distillate of petroleum, as distinct from usually edible vegetable oils. The name 'mineral oil' by itself is imprecise, having been used for many specific oils, since 1771. Other names, similarly imprecise, include 'white oil', 'paraffin oil', 'Liquid paraffin (medicinal), liquid paraffin' (a highly refined medical grade), (Latin), and 'liquid petroleum'. Most often, mineral oil is a liquid obtained from Oil refinery, refining crude oil to make gasoline and other petroleum products. Mineral oils used for lubrication are known specifically as base oils. More generally, mineral oil is a Transparency and translucency, transparent, colorless oil, composed mainly of alkanes and cycloalkanes, related to petroleum jelly. It has a density of around . Nomenclature Some of the imprecision in the definition of the names used for mineral oil (such as 'white oil') ref ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superheating
In thermodynamics, superheating (sometimes referred to as boiling retardation, or boiling delay) is the phenomenon in which a liquid is heated to a temperature higher than its boiling point, without boiling. This is a so-called ''metastable state'' or '' metastate'', where boiling might occur at any time, induced by external or internal effects.Debenedetti, P.G.Metastable Liquids: Concepts and Principles; Princeton University Press: Princeton, NJ, USA, 1996.Maris, H., Balibar, S. (2000"Negative Pressures and Cavitation in Liquid Helium"Physics Today 53, 29 Superheating is achieved by heating a homogeneous substance in a clean container, free of nucleation sites, while taking care not to disturb the liquid. This may occur by microwaving water in a very smooth container. Disturbing the water may cause an unsafe eruption of hot water and result in burns. Cause Water is said to "boil" when bubbles of water vapor grow without bound, bursting at the surface. For a vapor bubble ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quench
In materials science, quenching is the rapid cooling of a workpiece in water, gas, oil, polymer, air, or other fluids to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phase transformations, from occurring. It does this by reducing the window of time during which these undesired reactions are both thermodynamically favorable and kinetically accessible; for instance, quenching can reduce the crystal grain size of both metallic and plastic materials, increasing their hardness. In metallurgy, quenching is most commonly used to harden steel by inducing a martensite transformation, where the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. Rapid cooling prevents the formation of cementite structure, instead forcibly dissolving carbon atoms in the ferrite lattice. In steel alloyed with metals such as nickel and manganese, the eutectoid tempe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Case Hardening
Case-hardening or carburization is the process of introducing carbon to the surface of a low-carbon iron, or more commonly a low-carbon steel object, in order to harden the surface. Iron which has a carbon content greater than ~0.02% is known as steel. Steel which has a carbon content greater than ~0.25% can be direct-hardened by heating to around 600°C, and then quickly cooling, often by immersing in water or oil, known as quenching. Hardening is desirable for metal components because it gives increased strength and wear resistance, the tradeoff being that hardened steel is generally more brittle and less malleable than when it is in a softer state. In order to produce a hard skin on steels which have less than ~0.2% carbon, carbon can be introduced into the surface by heating steel in the presence of some carbon-rich substance such as powdered charcoal or hydrocarbon gas. This causes carbon to diffuse into the surface of the steel. The depth of this high carbon layer depend ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Gas
Coal gas is a flammable gaseous fuel made from coal and supplied to the user via a piped distribution system. It is produced when coal is heated strongly in the absence of air. Town gas is a more general term referring to manufactured gaseous fuels produced for sale to consumers and municipalities. The original coal gas was produced by the coal gasification reaction, and the burnable component consisted of a mixture of carbon monoxide and hydrogen in roughly equal quantities by volume. Thus, coal gas is highly toxicity, toxic. Other compositions contain additional Calorific Value, calorific gases such as methane, produced by the Fischer–Tropsch process, and volatile hydrocarbons together with small quantities of non-calorific gases such as carbon dioxide and nitrogen. Prior to the development of natural gas supply and transmission—during the 1940s and 1950s in the United States and during the late 1960s and 1970s in the United Kingdom and Australia—almost all gas for fu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naval Armour
Naval armor refers to the various protections schemes employed by warships. The first ironclad warship was created in 1859, and the pace of armour advancement accelerated quickly thereafter. The emergence of battleships around the turn of the 20th century saw ships become increasingly large and well armoured. Vast quantities of heavily armoured ships were used during the World Wars, and were crucial in the outcome. The emergence of guided missiles in the last part of the 20th century has greatly reduced the utility of armor, and most modern warships are now only lightly armored. Naval armour consists of many different designs, depending on what the armour is meant to protect against. Sloped armour and belt armour are designed to protect against shellfire; torpedo belts, bulges, and bulkheads protect against underwater torpedoes or naval mines; and armoured decks protect against air dropped bombs and long-range shellfire. The materials that make up naval armour have evolved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carburization
Carburizing, or carburising, is a heat treatment process in which iron or steel absorbs carbon while the metal is heated in the presence of a carbon-bearing material, such as charcoal or carbon monoxide. The intent is to make the metal harder and more wear resistant. Depending on the amount of time and temperature, the affected area can vary in carbon content. Longer carburizing times and higher temperatures typically increase the depth of carbon diffusion. When the iron or steel is cooled rapidly by quenching, the higher carbon content on the outer surface becomes hard due to the transformation from austenite to martensite, while the core remains soft and tough as a ferritic and/or pearlite microstructure. This manufacturing process can be characterized by the following key points: It is applied to low-carbon workpieces; workpieces are in contact with a high-carbon gas, liquid or solid; it produces a hard workpiece surface; workpiece cores largely retain their toughness an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
