Instruct: Given a question, retrieve relevant documents that answer the question.
Query: What is stainless steel?
In metallurgy, stainless steel,[1][2] also known as inox steel or inox from French inoxydable (inoxidizable), is a steel alloy, with highest percentage contents of iron, chromium, and nickel, with a minimum of 10.5% chromium content by mass and a maximum of 1.2% carbon by mass.[3][4]
In 1929, stainless steel was introduced for the use of making appliances. This was the first material that truly replaced the usage of noble alloys in Orthodontics. Steel wire alloys, in comparison to the noble metals, were relatively cheaper. They also had better formability and can be readily used to be soldered and welded for fabrication of complex orthodontic appliances. The stainless steel alloys are of "18-8" austenitic type which contain Chromium (17-25%) and Nickel (8-25%) and Carbon (1-2%). Chromium in this stainless steel alloy forms a thin oxide layer which blocks the diffusion of oxygen into the alloy and allow for the corrosion resistance of this alloy. Angle used stainless steel in his last year practicing orthodontics. He used it as a ligature wire in his patient's mouth. At that time, Emil Herbst was the main opponent of the Stainless steel based alloys. According to him, he preferred using Noble alloys over stainless steel. By 1950, 300 series stainless steel alloy was used by the majority of orthodontists in United States, as European Orthodontists believed in using functional appliances such as Activator appliance with patient's malocclusions. 
SAE 304 stainless steel is the most common stainless steel. The steel contains both chromium (between 18–20%) and nickel (between 8–10.5%) metals as the main non-iron constituents. It is an austenitic stainless steel. It is less electrically and thermally conductive than carbon steel and is essentially non-magnetic. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes.
Duplex stainless steels is the most recent family of stainless steels. 
The Allegheny Ludlum Corporation worked with Ford on various concept cars with stainless steel bodies from the 1930s through the 1970s to demonstrate the material's potential. The 1957 and 1958 Cadillac Eldorado Brougham had a stainless steel roof. In 1981 and 1982, the DeLorean DMC-12 production automobile used Type-304 stainless steel body panels over a glass-reinforced plastic monocoque. Intercity buses made by Motor Coach Industries are partially made of stainless steel.
When submerged a stainless steel with a PREN > 40 is typically specified as the minimum for resistance to seawater. Stainless steels, such as super austenitic stainless steels (for example UNS S31254 or N08367), or super duplex stainless steels (for example UNS S32760 or S32750) meet this requirement.
Surgical stainless steel is a grade of stainless steel used in biomedical applications. The most common "surgical steels" are austenitic 316 stainless and martensitic 440 and 420 stainless steels. There is no formal definition on what constitutes a "surgical stainless steel", so product manufacturers and distributors apply the term to refer to any grade of corrosion resistant steel.
440 and 420 stainless steels, known also by the name "Cutlery Stainless Steel", are high carbon steels alloyed with chromium. They have very good corrosion resistance compared to other cutlery steels, but their corrosion resistance is inferior to 316 stainless. Biomedical cutting instruments are often made from 440 or 420 stainless due to its high hardness coupled with acceptable corrosion resistance. This type of stainless steel may be slightly magnetic.
Rail cars have commonly been manufactured using corrugated stainless steel panels (for additional structural strength). This was particularly popular during the 1960s and 1970s, but has since declined. One notable example was the early Pioneer Zephyr. Notable former manufacturers of stainless steel rolling stock included the Budd Company (USA), which has been licensed to Japan's Tokyu Car Corporation, and the Portuguese company Sorefame. Many railcars in the United States are still manufactured with stainless steel. India is developing its rail infrastructure and has started to put new stainless steel coaches in service.[71] South Africa is also commissioning stainless steel coaches.[72]
Austenitic stainless steel is the largest family of stainless steels, making up about two-thirds of all stainless steel production. They possess an austenitic microstructure, which is a face-centered cubic crystal structure. This microstructure is achieved by alloying with sufficient nickel and/or manganese and nitrogen to maintain an austenitic microstructure at all temperatures from the cryogenic region to the melting point. Thus austenitic stainless steels are not hardenable by heat treatment since they possess the same microstructure at all temperatures.
Austenitic stainless steels Cr - Ni (also-called 300*-series): 54% Austenitic stainless steels Cr - Mn (also called 200*-series): 21% Ferritic and martensitic stainless steels (also called 400*-series): 23%
Surgical stainless steel is a grade of stainless steel that is used in biomedical applications. The most common "surgical steels" are austenitic 316 stainless and martensitic 440 and 420 stainless steels. There is no formal definition on what constitutes a "surgical stainless steel", so product manufacturers and distributors apply the term to refer to any grade of corrosion resistant steel.
They are generally made from carbon steel or stainless steel. Stainless steel belts are corrosion resistant and provide excellent surface quality. Stainless steel belts are used primarily in the chemical, food, rubber, plastic, wood, and laminate industries. Carbon steel belts are energy efficient and ideal for applications necessitating radiant heating of products or in high-temperature applications that might exceed the annealing temperatures of stainless steel belts also carbon steel belts can more evenly distributed heat since most stainless steel alloys are comparatively poor heat conductors. Carbon steel belts are used primarily in food processing, transport, and bake ovens. Textured Steel is also a commonly found belt material. The main purpose of using textured steel material is for its non-stick capabilities. This works well in the laminate industry.
The purpose of the Kemi Mine in the long production chain from chromite ore to stainless steel is to produce concentrates from ore as raw material for the manufacture of ferrochrome at the ferrochrome plant located in Tornio. The chrome contained in the ferrochrome generated as a product at the ferrochrome plant – used as an alloying material in the steel manufacturing process – is what makes the steel manufactured at the Tornio steel plant stainless.
Stainless steel also has a lesser-known application in spaceflight. So far, only the early Atlas rockets have used stainless steel (this formed their fuel tanks), but in the future the SpaceX BFR will be the second rocket to use stainless steel.
- select the rignt type of stainless steel: super austenitics such as grade 904L or super duplex (Ferritic stainless steels and duplex stainless steels are very resistant to SCC)
Stainless steels have a long history of application in contact with water[57] due to their excellent corrosion resistance. Applications include a range of conditions from plumbing,[58] potable[59] and waste water treatment[60] to desalination.[61] Types 304 and 316 stainless steels are standard materials of construction in contact with water. However, with increasing chloride contents higher alloyed stainless steels such as Type 2205 and super austenitic and super duplex stainless steels are utilized.[62]
Galvanic corrosion (also called ' dissimilar metal corrosion') refers to corrosion damage induced when two dissimilar materials are coupled in a corrosive electrolyte. The most common electrolyte is water, ranging from fresh water to seawater. When a galvanic couple forms, one of the metals in the couple becomes the anode and corrodes faster than it would all by itself, while the other becomes the cathode and corrodes slower than it would alone. Stainless steel, due to its superior corrosion resistance relative to most other metals, including steel and aluminum, becomes the cathode accelerating the corrosion of the anodic metal. An example is the corrosion of aluminum rivets fastening stainless steel sheets in contact with water.[18]. The relative surfaces of the anode and the cathode are important. In the above example, the surface of the rivets will be small compared to that of the stainless steel sheet. However if stainless steel fasteners are used to assemble aluminum sheets, glavanic corrosion will be much slower because the galvanic current density on the aluminum surface will be order of magnitude smaller. A similar, but frequent mistake, is to assemble stainless steel with carbon steel fasteners; wheras using stainless steel to fasten carbon steel steel plates is usually OK..[5]
Duplex stainless steels have a mixed microstructure of austenite and ferrite, the aim usually being to produce a 50/50 mix, although in commercial alloys the ratio may be 40/60. They are characterized by high chromium (19–32%) and molybdenum (up to 5%) and lower nickel contents than austenitic stainless steels. Duplex stainless steels have roughly twice the strength compared to austenitic stainless steels. Their mixed microstructure provides improved resistance to chloride stress corrosion cracking in comparison to austenitic stainless steels Types 304 and 316.
Martensitic stainless steel is a specific type of stainless steel alloy.
Austenitic stainless steel is a specific type of stainless steel alloy. Stainless steels may be classified by their crystalline structure into four main types: "austenitic", "ferritic," "martensitic and duplex." These stainless steels possess austenite as their primary crystalline structure (face centered cubic). This austenite crystalline structure is achieved by sufficient additions of the austenite stabilizing elements nickel, manganese and nitrogen. Due to their crystalline structure austenitic steels are not hardenable by heat treatment and are essentially non-magnetic.
Argon oxygen decarburization Corrugated stainless steel tubing Crucible Industries List of blade materials List of steel producers Pitting Resistance Equivalent Number Marine grade stainless Pilling–Bedworth ratio Rouging Stainless steel fiber Stainless steel soap
Some 3D printing providers have developed proprietary stainless steel sintering blends for use in rapid prototyping. One of the more popular stainless steel grades used in 3D printing is 316L stainless steel. Due to the high temperature gradient and fast rate of solidification, stainless steel products manufactured via 3D printing tend to have a more refined microstructure; this in turn results in better mechanical properties. However, stainless steel is not used as much as materials like Ti6Al4V in the 3D printing industry; this is because manufacturing stainless steel products via traditional methods is currently much more economically competitive.
Knife blades can be manufactured from a variety of materials, each of which has advantages and disadvantages. Carbon steel, an alloy of iron and carbon, can be very sharp. It holds its edge well, and remains easy to sharpen, but is vulnerable to rust and stains. Stainless steel is an alloy of iron, chromium, possibly nickel, and molybdenum, with only a small amount of carbon. It is not able to take quite as sharp an edge as carbon steel, but is highly resistant to corrosion. High carbon stainless steel is stainless steel with a higher amount of carbon, intended to incorporate the better attributes of carbon steel and stainless steel. High carbon stainless steel blades do not discolor or stain, and maintain a sharp edge. Laminated blades use multiple metals to create a layered sandwich, combining the attributes of both. For example, a harder, more brittle steel may be sandwiched between an outer layer of softer, tougher, stainless steel to reduce vulnerability to corrosion. In this case, however, the part most affected by corrosion, the edge, is still vulnerable. Damascus steel is a form of pattern welding with similarities to laminate construction. Layers of different steel types are welded together, but then the stock is manipulated to create patterns in the steel.
Currently stainless steel fibers are manufactured primarily in Europe.The most common uses for stainless steel fibers is in the field of the electrical and textiles industry such as anti-radiation cloth, thermal resistant fabric, and anti-static brushes. Many people also use stainless steel fibers in weaving. Increasingly common today are stainless steel fibers in clothing, including radiation protection for pregnant women. Stainless steel yarns are woven, braided, and knit into many industrial fabrics. For additional variety, stainless steel yarns are twisted with other fibers such as wool, nylon, cotton, and synthetic blends to produce yarns which add novelty effects to the end cloth. Stainless steel and other metal fibers are used in communication lines such as telephone lines and cable television lines. Stainless steel fibers are also used in carpets. They are dispersed throughout the carpet with other fibers so they are not detected. The presence of the fibers helps to conduct electricity so that the static shock is reduced. These types of carpets are often used in computer-use areas where risks of electrostatic discharge are much greater. Other uses include tire cord, missile nose cones, work clothing such as protective suits, space suits, and cut resistant gloves for butchers and other people working near bladed or dangerous machinery.