Typical applications include aircraft and the dairy and food-processing industries. The most common type is the 18/8, or 304, grade, which contains 18 percent chromium and 8 percent nickel. They are not hardenable by heat treatment and are nonmagnetic. Austenitic steels, which contain 16 to 26 percent chromium and up to 35 percent nickel, usually have the highest corrosion resistance. The majority are classified into five major groups in the family of stainless steels: austenitic, ferritic, martensitic, duplex, and precipitation-hardening. There are more than 100 grades of stainless steel. Thus, cheaper raw materials, such as high-carbon ferrochromium, may be used in the initial melting operation. By varying the ratio of oxygen and argon, it is possible to remove carbon to controlled levels by oxidizing it to carbon monoxide without also oxidizing and losing expensive chromium. In the argon-oxygen decarburization process, a mixture of oxygen and argon gas is injected into the liquid steel. Most stainless steels are first melted in electric-arc or basic oxygen furnaces and subsequently refined in another steelmaking vessel, mainly to lower the carbon content. Other elements, such as nickel, molybdenum, titanium, aluminum, niobium, copper, nitrogen, sulfur, phosphorus, or selenium, may be added to increase corrosion resistance to specific environments, enhance oxidation resistance, and impart special characteristics. In conjunction with low carbon content, chromium imparts remarkable resistance to corrosion and heat. Stainless steel, any one of a family of alloy steels usually containing 10 to 30 percent chromium. They contain 16 to 26 percent chromium and up to 35 percent nickel, and they are not hardenable by heat treatment and are nonmagnetic. SpaceNext50 Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!Īustenitic steels usually have the highest corrosion resistance.Learn about the major environmental problems facing our planet and what can be done about them! Saving Earth Britannica Presents Earth’s To-Do List for the 21st Century.Britannica Beyond We’ve created a new place where questions are at the center of learning.100 Women Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians.COVID-19 Portal While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today.Student Portal Britannica is the ultimate student resource for key school subjects like history, government, literature, and more.Demystified Videos In Demystified, Britannica has all the answers to your burning questions.This Time in History In these videos, find out what happened this month (or any month!) in history.#WTFact Videos In #WTFact Britannica shares some of the most bizarre facts we can find.Britannica Classics Check out these retro videos from Encyclopedia Britannica’s archives.Britannica Explains In these videos, Britannica explains a variety of topics and answers frequently asked questions.
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