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Boron Steel
Boron steel refers to steel alloyed with a small amount of boron, usually less than 1%. The addition of boron to steel greatly increases the hardenability of the resulting alloy. Description Boron is added to steel as ferroboron (~12-24% B). As the ferroboron addition lacks protective elements it is usually added after oxygen scavengers have been added. Proprietary additives also exist with oxygen/nitrogen scavengersone such contains 2% B plus Al, Ti, Si. Oxygen, carbon, and nitrogen react with boron in steel to form B2O3 (boron trioxide); Fe3(CB) ( iron boroncementite) and Fe23(CB)6 ( iron boroncarbide); and BN (boron nitride) respectively. Hardenability Soluble boron arranges in steels along grain boundaries. This inhibits the γ-α transformations (austenite to ferrite transformation) by diffusion and therefore increases the hardenability, with an optimal range of ~ 0.0003 to 0.003% B. Additionally Fe2B has been found to precipitate at grain boundaries, which may also retar ... [...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] |
High-strength Low-alloy Steel
High-strength low-alloy steel (HSLA) is a type of alloy steel that provides better mechanical properties or greater resistance to corrosion than carbon steel. HSLA steels vary from other steels in that they are not made to meet a specific chemical composition but rather specific mechanical properties. They have a carbon content between 0.05 and 0.25% to retain formability and weldability. Other alloying elements include up to 2.0% manganese and small quantities of copper, nickel, niobium, nitrogen, vanadium, chromium, molybdenum, titanium, calcium, rare-earth elements, or zirconium. Copper, titanium, vanadium, and niobium are added for strengthening purposes. These elements are intended to alter the microstructure of carbon steels, which is usually a ferrite-pearlite aggregate, to produce a very fine dispersion of alloy carbides in an almost pure ferrite matrix. This eliminates the toughness-reducing effect of a pearlitic volume fraction yet maintains and increases the material's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron Boride
Iron boride refers to various inorganic compounds with the formula FexBy. Two main iron borides are FeB and Fe2B. Some iron borides possess useful properties such as magnetism, electrical conductivity, corrosion resistance and extreme hardness. Some iron borides have found use as hardening coatings for iron. Iron borides have properties of ceramics such as high hardness, and properties of metal properties, such as thermal conductivity and electrical conductivity. Boride coatings on iron are superior mechanical, frictional, and anti-corrosive. Iron monoboride (FeB) is a grey powder that is insoluble in water. FeB is harder than Fe2B, but is more brittle and more easily fractured upon impact. Formation Thermochemical Formation Iron borides can be formed by thermochemically reacting boron rich compounds on an iron surface to form a mixture of iron borides, in a process known as boriding. There are a number of ways of forming boride coatings, including gas boriding, molten salt bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boriding
Boriding, also called boronizing, is the process by which boron is added to a metal or alloy. It is a type of surface hardening. In this process boron atoms are diffused into the surface of a metal component. The resulting surface contains metal borides, such as iron borides, nickel borides, and cobalt borides, As pure materials, these borides have extremely high hardness and wear resistance. Their favorable properties are manifested even when they are a small fraction of the bulk solid.Helmut Kunst, Brigitte Haase, James C. Malloy, Klaus Wittel, Montia C. Nestler, Andrew R. Nicoll, Ulrich Erning and Gerhard Rauscher "Metals, Surface Treatment" in Ullmann's Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. Boronized metal parts are extremely wear resistant and will often last two to five times longer than components treated with conventional heat treatments such as hardening, carburizing, nitriding, nitrocarburizing or induction hardening. Most borided steel surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Padlock
Padlocks are portable locks with a shackle that may be passed through an opening (such as a chain link, or hasp staple) to prevent use, theft, vandalism or harm. Naming and etymology The term ''padlock'' is from the late fifteenth century. The prefix pad- is of unknown origin; it is combined with the noun lock, from Old English ''loc'', related to German ''loch'', "hole". History There are padlocks dating to the Roman Era, 500 BC – 300 AD. They were known in early times by merchants traveling the ancient trade routes to Asia, including China. Padlocks have been used in Europe since the middle La Tène period, subsequently spreading to the Roman world and the Przeworsk and Chernyakhov cultures.Katarzyna Czarnecka, "Padlocks In The Przeworsk And The Chernyakhov Cultures In The Late Roman Period, As An Evidence Of Mutual Contacts." Roman padlocks had a long bent rod attached to the case, and a shorter piece which could be inserted into the case. Przeworsk and Chernyakhov pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultimate Tensile Strength
Ultimate tensile strength (UTS), often shortened to tensile strength (TS), ultimate strength, or F_\text within equations, is the maximum stress that a material can withstand while being stretched or pulled before breaking. In brittle materials the ultimate tensile strength is close to the yield point, whereas in ductile materials the ultimate tensile strength can be higher. The ultimate tensile strength is usually found by performing a tensile test and recording the engineering stress versus strain. The highest point of the stress–strain curve is the ultimate tensile strength and has units of stress. The equivalent point for the case of compression, instead of tension, is called the compressive strength. Tensile strengths are rarely of any consequence in the design of ductile members, but they are important with brittle members. They are tabulated for common materials such as alloys, composite materials, ceramics, plastics, and wood. Definition The ultimate tensile strength ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proof Strength
In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and will 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 and is known as plastic deformation. The yield strength or yield stress is a material property and is the stress corresponding to the yield point at which the material begins to deform plastically. The yield strength is often used to determine the maximum allowable load in a mechanical component, since it represents the upper limit to forces that can be applied without producing permanent deformation. In some materials, such as aluminium, there is a gradual onset of non-linear behavior, making the precise yield point difficult to determine. In such a case, the offset yield ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminized Steel
Aluminized steel is steel that has been plated with aluminium or aluminium-silicon alloy, in a process analogous to hot-dip galvanizing. The steel workpiece is immersed in molten aluminum to produce a tight metallic bond between the steel and coating. The product has a unique combination of properties possessed by neither steel alone nor aluminium alone. Aluminized steel is more resistant to corrosion than bare steel while retaining properties of steel, at temperature lower than the melting point of aluminum, . Common applications include heat exchangers in residential furnaces, commercial rooftop HVAC units, automotive mufflers, ovens, kitchen ranges, water heaters, fireplaces, barbecue burners, and baking pans. Aluminized steel transfers heat more effectively than bare steel. It often serves where galvanized steel might have been used historically, without galvanized steel's drawbacks. Characteristics vary depending on the aluminum alloy used. Types ; Type 1: Hot-dip coate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Stamping (steel)
Hot stamping (also known as press hardening, hot press forming, or hot forming die quenching) is a relatively new technology which allows ultra-high strength steels (typically 22MnB5 boron steel) to be formed into complex shapes, which is not possible with regular cold stamping operations. This process is commonly used for the production of automotive body in white components because its advantages align with the design criteria of modern passenger vehicles. Methods ;Direct Process: The unformed blank is heated in a furnace, formed in hot condition (state 2 in below figure), and quenched in the die to achieve the required properties. ;Indirect Process: The blank is formed, trimmed, and pierced in cold condition (i.e., state 1 in below figure). It is later heated and quenched in a die to get high strength properties. Selection of the process depends on part complexity and blank coating ( Zn based coatings typically require indirect process). In either method, the blank is forme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Rescue Tool
Hydraulic rescue tools, also known as jaws of life, are used by emergency rescue personnel to assist in the extrication of victims involved in vehicle accidents, as well as other rescues in small spaces. These tools include cutters, spreaders, and rams. Such devices were first used in 1963 as a tool to free race car drivers from their vehicles after crashes. History The Hurst Rescue Tool was invented by George Hurst, circa 1961, after he viewed a stock car race accident in which it took workers over an hour to remove an injured driver from his car. Previously rescuers often used circular saws for vehicle extrication, but these suffered from several drawbacks. Saws can create sparks, which could start a fire, create loud sounds, stress the victim(s), and often cut slowly. Alternatively, rescuers could try to pry open the vehicle doors with a crowbar or Halligan bar, but this could compromise the stability of the vehicle, or injure the victims further. In comparison, hydrauli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stainless Steel
Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corrosion resistance, resistance to corrosion results from the chromium, which forms a Passivation (chemistry), passive film that can protect the material and self-healing material, self-heal in the presence of oxygen. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications. Stainless steel can be rolled into Sheet metal, sheets, plates, bars, wire, and tubing. These can be used in cookware, cutlery, surgical instruments, major appliances, vehicles, construction material in large buildings, industrial equipment (e.g., in paper mills, chemical plants, water treatment), and storage tanks and tankers for chemicals and food products. The biological cleanability of stainless steel is superior to both alumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutron Absorption
Neutron capture is a nuclear reaction in which an atomic nucleus and one or more neutrons collide and merge to form a heavier nucleus. Since neutrons have no electric charge, they can enter a nucleus more easily than positively charged protons, which are repelled electrostatically. Neutron capture plays a significant role in the cosmic nucleosynthesis of heavy elements. In stars it can proceed in two ways: as a rapid process (r-process) or a slow process (s-process). Nuclei of masses greater than 56 cannot be formed by thermonuclear reactions (i.e., by nuclear fusion) but can be formed by neutron capture. Neutron capture on protons yields a line at 2.223 MeV predicted and commonly observed in solar flares. Neutron capture at small neutron flux At small neutron flux, as in a nuclear reactor, a single neutron is captured by a nucleus. For example, when natural gold (197Au) is irradiated by neutrons (n), the isotope 198Au is formed in a highly excited state, and quickly deca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
