Monel is a group of nickel alloys, mainly composed of nickel (up to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon. Stronger than pure nickel, Monel alloys are resistant to corrosion by many agents, including fast-flowing seawater. They can be made easily with hot, cold work, workmanship and welding.
Monel was created by Robert Crooks Stanley, who worked for the International Nickel Company (INCO) in 1901. The Monel 400 alloy is a binary mixture of the same proportion of nickel and copper as found naturally in nickel ore from the Sudbury (Ontario) mine and because it is considered a puritan alloy. Monel was named after the president of the company Ambrose Monell, and patented in 1906. One L was dropped, because the surname was not allowed as a trademark at the time. This name is now a trademark of Special Metals Corporation.
This is a very expensive alloy, with costs ranging from 5 to 10 times the cost of copper and nickel, so its use is limited to applications that can not be replaced by cheaper alternatives. Compared to carbon steel, the pipeline at Monel is more than 3 times more expensive.
Video Monel
Properti
Monel is a solid solution binary alloy. Since nickel and copper dissolve in all proportions, it is a single-phase alloy. Compared to steel, Monel is very difficult to work because it works very quickly. This needs to be changed and works with slow speed and low feed prices. It is resistant to corrosion and acid, and some alloys can withstand fire in pure oxygen. It is commonly used in applications with very corrosive conditions. The addition of a small aluminum and titanium alloy forms (K-500) with the same corrosion resistance but with a much greater force due to the formation of bima gamma in aging. Monel is usually much more expensive than stainless steel.
Monel alloy 400 has a specific gravity of 8.80, a melting range of 1300-1350 Â ° C, electrical conductivity of about 34% of IACS, and (in annealing condition) 65 Rockwell B. Monel alloy 400 is important for its toughness, which is maintained over the temperature range which is quite large.
Monel alloy 400 has excellent mechanical properties at temperatures below zero. Strength and hardness increase only with a slight decrease in ductility or impact resistance. Alloys do not undergo tough transition to brittle even when cooled to liquid hydrogen temperature. This is very different from many fragile iron materials at low temperatures despite their increased strength.
Maps Monel
Usage
Aerospace application
In the 1960s, Monel metals discovered mass usage in aircraft construction, particularly in making skeletons and skins of experimental rocket planes, such as North America X-15, to withstand the intense heat generated by aerodynamic friction during very high-speed flights. Monel metal retains its strength at extremely high temperatures, allowing it to retain its shape at high atmospheric flight speeds, a trade off on increasing the weight of parts due to Monel's high density.
Monel is used for safety cables in aircraft maintenance to ensure that fasteners can not escape, usually in high-temperature areas; Stainless wire is used in other areas for economy.
Oil production and refining
Monel is used in the Alkylation unit section in direct contact with concentrated hydrofluoric acid. Monel offers exceptional resistance to fluoride acid in all concentrations to the boiling point. It may be the most resistant of all commonly used engineering alloys. This alloy is also resistant to various forms of sulfuric acid and hydrochloric in the reduction conditions.
Ocean applications
Monel corrosion resistance makes it ideal in applications such as piping systems, pump shafts, marine water valves, trolling wire, and filter baskets. Some alloys are completely non-magnetic and are used for anchor cables on minesweepers, homes for magnetic field measurement equipment. In recreational boating, Monel wire is used to seize the shackles for anchor ropes, Monel is used for water tanks and fuels, and for underwater applications. It is also used for the propeller shaft and for the keel bolts. In the popular Hobiecat sailboat, Monel rivets are used where strength is required but stainless steels can not be used because of the corrosion problem that will result from having stainless steels in contact with aluminum poles, booms and boat skeletons, in saltwater environments..
However, due to the problem of electrolytic action in brine (also known as Galvanic corrosion), in the construction of Monel ships should be carefully insulated from other metals such as steel. The New York Times on August 12, 1915 published an article about a 215-foot cruise ship, "the first ship ever built with a fully hulled Monel," which was "destroyed" in just six weeks and had to be discarded, "due to the disintegration of his butt by electrical action." The yacht steel frame is worsening due to electrolytic interactions with Monel.
In seabird studies, and in particular milkfish or ringing, Monel has been used to create bird bands or rings for many species such as albatross that live in corrosive sea water environments.
Musical instruments
Monel is used as material for piston valves or rotor in some high quality musical instruments such as trumpet, tuba and French horn. RotoSound introduced the use of Monel for electric bass strings in 1962, and this string has been used by many artists, including Steve Harris of Iron Maiden, The Who, Sting, John Deacon, John Paul Jones and the late Chris Squire. Monel was used in the early 1930s by other string musical producers, such as Gibson Guitar Corporation, who continue to offer them to mandolins as Sam Bush's signature. Also, C.F. Martin & amp; Co uses Monel for their Martin Retro acoustic guitar strings. The Pyramid String Factory (Germany) produces a 'classic Monel' electric guitar string, wrapped around a round core. In 2017, string company D'Addario released a string line of violins using Monel winding on the D and G strings.
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Good resistance to corrosion by acid and oxygen makes Monel a good material for the chemical industry. Even corrosive fluoride can be handled in the Monel apparatus; this is done in a vast manner in uranium enrichment at the Oak Ridge Gas Diffusion Plant. Here most of the larger diameter tubes for uranium hexafluoride are made from Monel. Regulators for reactive cylindrical gases such as hydrogen chloride form another example, where PTFE is not a suitable choice when high delivery pressure is required. This sometimes includes a Monel manifold and tap before the regulator that allows the regulator to flush with inert gaseous after being used to further protect the equipment.
At the beginning of the 20th century, when steam power was widely used, Monel was advertised as desirable for use in super hot steam systems. During the world war, Monel was used to tag US military dogs.
Monel is often used for kitchen sinks and in eyeglass frames. It has also been used to live in a fire-fireplace boiler tube.
Parts of the Long Clock Now, intended to run for 10,000 years, are made of Monel due to corrosion resistance without the use of precious metals.
Monel is used for many exposed metals used in the interior of Bryn Athyn Cathedral in Pennsylvania, the religious position of the New Jerusalem General Church. These include large decorative screens, door handles, etc. Monel has also been used as a roofing material in buildings such as the original Pennsylvania Station in New York City.
The 1991-1996 Acura (Honda) NSX comes with a key made of Monel.
Applications of oil fields include using Monel (rarely - see drilling direction above) in both flexible and slippery collars. The instrument (magnetometer or compass) that measures the Earth's magnetic field to obtain a magnetic direction is placed in a non-magnetic collar that isolates the sensor from the magnetic drill of the drill located above and below the non-magnetic collar. They are often referred to as "Monel collars" because it is the first material used to make collars and names that are jammed.
Monel is also used as a protective material that binds on the outside of the western-style stirrups.
Monel is used by Arrow Fastener Co., Inc. for T50 stainless staples.
Monel has also been used in the Kelvinator refrigerator.
Monel is used in Baby Alice Thumb Guard, a 1930s anti-thumb device.
Alloy
Monel 400
Monel 400 demonstrates high strength and excellent corrosion resistance in a variety of acidic and alkaline environments and is particularly suitable for reducing conditions. It also has good ductility and thermal conductivity. Monel 400 typically finds applications in marine engineering, chemical and hydro-carbon processes, heat exchangers, valves and pumps. These are covered by the following standards: BS 3075, 3076 NA 13, DTD 204B and ASTM B164.
The large use of Monel 400 is made in the alkylation unit, ie in the reacting part of contact with concentrated hydrofluoric acid.
Monel 401
These alloys are designed for use in special electrical and electronic applications. The 401 alloy is readily welded autogenously by the tungsten-arc gas process. Las resistance is a very satisfying method to join the material. It also shows good brazing characteristics. This is covered by the standard UNS N04401.
Monel 404
Monel 404 alloys are used primarily in special electrical and electronic applications. The Monel 404 composition is carefully adjusted to provide very low Curie temperatures, low permeability, and good brazing characteristics.
Monel 404 can be welded using ordinary and forged welding techniques but can not be worked with heat. Cold work can be done using standard tools and soft die materials for better finish. It is covered by the standards of UNS N04404 and ASTM F96. These alloys are used in the following applications: capsules for transistors and ceramics for metal sealing.
Monel 450
These alloys exhibit good fatigue strength and have relatively high thermal conductivity. It is used for seawater condensers, condenser plates, distillation tubes, evaporator tubes and heat exchangers, and saltwater piping.
Monel K-500
The Monel K-500 combines excellent corrosion resistance characteristics from the Monel 400 alloy with the added advantage of greater strength and hardness. Increased properties are obtained by adding aluminum and titanium to the nickel-copper base, and by heating under controlled conditions so that the submicroscopic particles Ni3 (Ti, Al) are deposited throughout the matrix.
The corrosion resistance of Monel K-500 alloys is substantially equivalent to alloy 400 except that, when under aging conditions, the K-500 alloy has a greater tendency toward stress-corrosion cracking in some environments. The Monel K-500 alloy has been found to be resistant to the acid-gas environment. The combination of very low corrosion rates in high-speed seawater and high strength makes the K-500 alloy very suitable for centrifugal pump shafts in marine services. In stagnant or slow-moving sea water, fouling can occur followed by pitting, but this pitting slows after a fairly early attack.
Typical applications for the K-500 alloy are: pump and impeller shafts, physician knives and scrapers, collars and drilling instruments for oil drill and electronic components.
Monel R-405
Monel R-405 is a free engine version of Monel 400. It is a nickel-copper alloy with controlled amounts of sulfur added to provide sulphide inclusions that act as chip breakers during machining. Like the Monel 400, the R-405 alloy is resistant to seawater and steam at high temperatures as well as saline and caustic solutions. Monel R-405 is a solid solution alloy that can only be hardened by cold work. These nickel alloys exhibit characteristics such as good corrosion resistance, good welding capability and high strength. Low corrosion rates in brackish or rapidly flowing seawater combined with excellent resistance to corrosion crack stress in most of the freshwaters combined with their resistance to various corrosive conditions justifies their widespread use in marine applications and other non-oxidizing chloride solutions. These nickel-copper alloys are highly resistant to hydrochloric acid and hydrofluorate when they are de-aerated. As expected from high copper content, the R-405 alloy is rapidly attacked by nitric acid and the ammonia system.
The R-405 Alloy is mainly used for automatic screw stock and is generally not recommended for other applications.
See also
- Cupronickel
- Hastelloy
- Inconel
References
Bibliography
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Shoemaker, Lewis E.; Smith, Gaylord D. (2006). "A Century of Monel Metal: 1906-2006". JOM . 58 (9): 22. bibcode: 2006JOM.... 58i..22S. doi :. 10,1007/s11837-006-0077-x < span> Ã,
External links
- Monel Corrosion
Source of the article : Wikipedia
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