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SAF 2205
SAF 2205, also known as Sandvik SAF 2205, is a Sandvik-owned trademark for a 22Cr duplex (ferritic-austenitic) stainless steel. ''SAF'' derives from ''S''andvik ''A''ustenite ''F''errite. The nominal chemical composition of SAF 2205 is 22% chromium, 5% nickel, 3.2% molybdenum and other alloying elements such as nitrogen and manganese. The UNS designation for SAF 2205 is S31803/S32205 and the EN steel no. is 1.4462. SAF 2205 or Duplex 2205 is often used as an alternative to expensive 904L stainless steel owing to similar properties but cheaper ingredients. Duplex stainless steel is available in multiple forms like bars, billets, pipes, tubes, sheets, plates and even processed to fittings and flanges. Typical properties of SAF 2205 duplex stainless steel are: * high resistance to stress corrosion cracking (SCC) in chloride-bearing environments * high resistance to stress corrosion cracking (SCC) in environments containing hydrogen sulphide * high resistance to general corrosion, pi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sandvik
Sandvik AB is a Swedish multinational engineering company specializing in metal cutting, digital and additive manufacturing, mining and construction, stainless and special steel alloys, and industrial heating. The company was founded in Sweden in 1862. In 2020, the Sandvik Group had approximately 37,000 employees and revenues of about 86 billion SEK in more than 160 countries. History The beginning The company was founded by Göran Fredrik Göransson in 1862. He was an early user of the Bessemer process on an industrial scale. The company started as Högbo Stål & Jernverks AB in Sandviken, Sweden and was later reorganized as Sandvikens Jernverk (Ironworks) AB in 1868. The Sandvik brand name was first used officially in 1876 when Sandvik began selling products in the USA. Sandvikens Jernverk was introduced on the Stockholm Stock Exchange in 1901. In the 1860s, sales were conducted through trading houses in Sweden, Norway, Denmark, the UK, Russia, Germany and France. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pitting Corrosion
Pitting corrosion, or pitting, is a form of extremely localized corrosion that leads to the random creation of small holes in metal. The driving power for pitting corrosion is the depassivation of a small area, which becomes anodic (oxidation reaction) while an unknown but potentially vast area becomes cathodic (reduction reaction), leading to very localized galvanic corrosion. The corrosion penetrates the mass of the metal, with a limited diffusion of ions. Another term arises, pitting factor, which is defined as the ratio of the depth of the deepest pit (resulting due to corrosion) to the average penetration, which can be calculated based on the weight loss. Development and kinetics of pitting According to Frankel (1998) who performed a review on pitting corrosion, it develops in three successive steps: (or nucleation) by breakdown of the passive film protecting the metal surface from oxidation, (2) growth of metastable pits (growing up to the micron scale and then repassiva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Steel Producers
This is a list of the largest steel-producing companies in the world mostly based on the list by the World Steel Association. This list ranks steelmakers by volume of steel production in millions of tonnes and includes all steelmakers with production over 10 million in 2021. The World Steel Association compiles a list from its members every year. Note that due to mergers, year-to-year figures for some producers are not comparable. Also note that not all steel is the same; some steel is more valuable than other steel, so volume is not the same as turnover. Top producers by volume Other top steel producers by volume * Acerinox, Spain * Aisha Steel Mills, Pakistan * Aichi Steel Corporation, Japan * Allegheny Technologies, United States * Altos Hornos de México, Mexico * Angang Steel Company Limited, China * Anyang Steel, China * Aperam, Luxembourg * Arrium, Australia * BlueScope, Australia * British Steel Ltd, United Kingdom * BSRM, Bangladesh * Byelorussian Steel Works, Bel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferritic Stainless Steel
Ferritic stainless steel forms one of the five stainless steel families, the other four being austenitic, martensitic, duplex stainless steels, and ''precipitation hardened''. For example, many of AISI 400-series of stainless steels are ferritic steels. By comparison with austenitic types, these are less hardenable by cold working, less weldable, and should not be used at cryogenic temperatures. Some types, like the 430, have excellent corrosion resistance and are very heat tolerant. History Canadian-born engineer Frederick Mark Becket (1875-1942) at Union Carbide industrialised ferritic stainless steel around 1912, on the basis of "using silicon instead of carbon as a reducing agent in metal production, thus making low-carbon ferroalloys and certain steels practical". He discovered a ferrous alloy with 25-27% Chromium that "was the first of the high-chromium alloys that became known as heat-resisting stainless steel." Ferritic stainless steels were discovered early but it was on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duplex Stainless Steel
Duplex stainless steels are a family of stainless steels. These are called duplex (or austenitic-ferritic) grades because their metallurgical structure consists of two phases, austenite (face-centered cubic lattice) and ferrite (body centered cubic lattice) in roughly equal proportions. They are designed to provide better corrosion resistance, particularly chloride stress corrosion and chloride pitting corrosion, and higher strength than standard austenitic stainless steels such as Type 304 or 316. The main differences in composition, when compared with an austenitic stainless steel is that the duplex steels have a higher chromium content, 20–28%; higher molybdenum, up to 5%; lower nickel, up to 9% and 0.05–0.50% nitrogen. Both the low nickel content and the high strength (enabling thinner sections to be used) give significant cost benefits. They are therefore used extensively in the offshore oil and gas industry for pipework systems, manifolds, risers, etc. and in the petroche ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weldability
The weldability, also known as joinability,. of a material refers to its ability to be welded. Many metals and thermoplastics can be welded, but some are easier to weld than others (see Rheological weldability). A material's weldability is used to determine the welding process and to compare the final weld quality to other materials. Weldability is often hard to define quantitatively, so most standards define it qualitatively. For instance the International Organization for Standardization (ISO) defines weldability in ISO standard 581-1980 as: "Metallic material is considered to be susceptible to welding to an established extent with given processes and for given purposes when welding provides metal integrity by a corresponding technological process for welded parts to meet technical requirements as to their own qualities as well as to their influence on a structure they form." Other welding organizations define it similarly. Steels For steel there are three major failure modes by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erosion Corrosion
Erosion corrosion is a degradation of material surface due to mechanical action, often by impinging liquid, abrasion by a slurry, particles suspended in fast flowing liquid or gas, bubbles or droplets, cavitation, etc. The mechanism can be described as follows: * mechanical erosion of the material, or protective (or passive) oxide layer on its surface, * enhanced corrosion of the material, if the corrosion rate of the material depends on the thickness of the oxide layer. The mechanism of erosion corrosion, the materials affected by it, and the conditions when it occurs are generally different from that of flow-accelerated corrosion, although the last one is sometimes classified as a sub-type of erosion corrosion. See also * Corrosion engineering * Tribocorrosion * Tribology * Wear Wear is the damaging, gradual removal or deformation of material at solid surfaces. Causes of wear can be mechanical (e.g., erosion) or chemical (e.g., corrosion). The study of wear and related pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crevice Corrosion
Crevice corrosion refers to corrosion occurring in occluded spaces such as interstices in which a stagnant solution is trapped and not renewed. These spaces are generally called crevices. Examples of crevices are gaps and contact areas between parts, under gaskets or seals, inside cracks and seams, spaces filled with deposits and under sludge piles. Mechanism The corrosion resistance of a stainless steel is dependent on the presence of an ultra-thin protective oxide film (passive film) on its surface, but it is possible under certain conditions for this oxide film to break down, for example in halide solutions or reducing acids. Areas where the oxide film can break down can also sometimes be the result of the way components are designed, for example under gaskets, in sharp re-entrant corners or associated with incomplete weld penetration or overlapping surfaces. These can all form crevices which can promote corrosion. To function as a corrosion site, a crevice has to be of suffi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress Corrosion Cracking
Stress corrosion cracking (SCC) is the growth of crack formation in a corrosive environment. It can lead to unexpected and sudden failure of normally ductile metal alloys subjected to a tensile stress, especially at elevated temperature. SCC is highly chemically specific in that certain alloys are likely to undergo SCC only when exposed to a small number of chemical environments. The chemical environment that causes SCC for a given alloy is often one which is only mildly corrosive to the metal. Hence, metal parts with severe SCC can appear bright and shiny, while being filled with microscopic cracks. This factor makes it common for SCC to go undetected prior to failure. SCC often progresses rapidly, and is more common among alloys than pure metals. The specific environment is of crucial importance, and only very small concentrations of certain highly active chemicals are needed to produce catastrophic cracking, often leading to devastating and unexpected failure.ASM Internation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromium
Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardness. A major development in steel production was the discovery that steel could be made highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating (electroplating with chromium) together comprise 85% of the commercial use. Chromium is also greatly valued as a metal that is able to be highly polished while resisting tarnishing. Polished chromium reflects almost 70% of the visible spectrum, and almost 90% of infrared light. The name of the element is derived from the Greek word χρῶμα, ''chrōma'', meaning color, because many chromium compounds are intensely colored. Industrial production of chromium proceeds from chromite ore (mostly FeCr2O4) to produce ferro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unified Numbering System
The unified numbering system (UNS) is an alloy designation system widely accepted in North America. Each UNS number relates to a specific metal or alloy and defines its specific chemical composition, or in some cases a specific mechanical or physical property. A UNS number alone does not constitute a full material specification because it establishes no requirements for material properties, heat treatment, form, or quality. History During the early 20th century many different metal alloys were developed in isolation within certain industries to meet the needs of that industry. This allowed a wide variety of competing standards, compositions and designations to flourish. By the 1960s there were a number of differing numbering or designation schemes for various alloys. This meant that the same number might be used for different alloys, different numbers might be used for the same alloy or different trade names might indicate similar or wildly different alloys. Additionally, the incre ... [...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] |
