page_title: Manganese
section_title: Steel
hierarchical_section_title: Manganese / Applications / Steel
caption_attribution_description: M1917 US brodie/doughboy helmet - front. From source website:"5th Marines painted helmet. Interesting features of this helmet would be the chinstrap which is "twisted". This must have slipped past quality control. Also, the helmet is identified to E. Echiner. His name is stamped into the leather on the chinstrap. The painted insignia is in three colors; red, black and orange. " Deutsch: Brodie-Helm (MK I) English: US Marine Corps M1917 Brodie pattern helmet Español: Casco de diseño Brodie de las fuerzas estadounidenses Русский: у английской каски, похожей на шляпу, имеются развитые поля
context_page_description: Manganese is a chemical element with the symbol Mn and atomic number 25. It is not found as a free element in nature; it is 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.
  Historically, manganese is named for pyrolusite and other black minerals from the region of Magnesia in Greece, which also gave its name to magnesium and the iron ore magnetite. By the mid-18th century, Swedish-German chemist Carl Wilhelm Scheele had used pyrolusite to produce chlorine. Scheele and others were aware that pyrolusite contained a new element, but they were unable to isolate it. Johan Gottlieb Gahn was the first to isolate an impure sample of manganese metal in 1774, which he did by reducing the dioxide with carbon.
  Manganese phosphating is used for rust and corrosion prevention on steel. Ionized manganese is used industrially as pigments of various colors, which depend on the oxidation state of the ions. The permanganates of alkali and alkaline earth metals are powerful oxidizers. Manganese dioxide is used as the cathode material in zinc-carbon and alkaline batteries.
context_section_description: Manganese is essential to iron and steel production by virtue of its sulfur-fixing, deoxidizing, and alloying properties, as first recognized by the British metallurgist Robert Forester Mushet (1811–1891) who, in 1856, introduced the element, in the form of Spiegeleisen, into steel for the specific purpose of removing excess dissolved oxygen, sulfur, and phosphorus in order to improve its malleability. Steelmaking, including its ironmaking component, has accounted for most manganese demand, presently in the range of 85% to 90% of the total demand. Manganese is a key component of low-cost stainless steel. Often ferromanganese (usually about 80% manganese) is the intermediate in modern processes.
  Small amounts of manganese improve the workability of steel at high temperatures by forming a high-melting sulfide and preventing the formation of a liquid iron sulfide at the grain boundaries. If the manganese content reaches 4%, the embrittlement of the steel becomes a dominant feature. The embrittlement decreases at higher manganese concentrations and reaches an acceptable level at 8%. Steel containing 8 to 15% of manganese has a high tensile strength of up to 863 MPa. Steel with 12% manganese was discovered in 1882 by Robert Hadfield and is still known as Hadfield steel (mangalloy). It was used for British military steel helmets and later by the U.S. military.
caption: U.S. M1917 combat helmet, a variant of Brodie helmet, made from Hadfield steel manganese alloy.
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