The strengthening effect of forming stable metal carbides at grain boundaries, and the strong increase in corrosion resistance made chromium an important alloying material for steel. High-speed tool steels contain between 3 and 5\% chromium. Stainless steel, the primary corrosion-resistant metal alloy, is formed when chromium is introduced to iron in concentrations above 11\%. For stainless steel's formation, ferrochromium is added to the molten iron. Also, nickel-based alloys have increased strength due to the formation of discrete, stable, metal, carbide particles at the grain boundaries. For example, Inconel 718 contains 18.6\% chromium. Because of the excellent high-temperature properties of these nickel superalloys, they are used in jet engines and gas turbines in lieu of common structural materials. ASTM B163 relies on Chromium for condenser and heat-exchanger tubes, while castings with high strength at elevated temperatures that contain Chromium are standardised with ASTM A567. AISI type 332 is used where high temperature would normally cause carburization, oxidation or corrosion. Incoloy 800 "is capable of remaining stable and maintaining its austenitic structure even after long time exposures to high temperatures". Nichrome is used as resistance wire for heating elements in things like toasters and space heaters. These uses make chromium a strategic material. During World War II it was a subject of intense diplomacy to keep it out of the hands of Nazi Germany.
The strengthening effect of forming stable metal carbides at grain boundaries, and the strong increase in corrosion resistance made chromium an important alloying material for steel. High-speed tool steels contain between 3 and 5\% chromium. Stainless steel, the primary corrosion-resistant metal alloy, is formed when chromium is introduced to iron in concentrations above 11\%. For stainless steel's formation, ferrochromium is added to the molten iron. Also, nickel-based alloys have increased strength due to the formation of discrete, stable, metal, carbide particles at the grain boundaries. For example, Inconel 718 contains 18.6\% chromium. Because of the excellent high-temperature properties of these nickel superalloys, they are used in jet engines and gas turbines in lieu of common structural materials. ASTM B163 relies on Chromium for condenser and heat-exchanger tubes, while castings with high strength at elevated temperatures that contain Chromium are standardised with ASTM A567. AISI type 332 is used where high temperature would normally cause carburization, oxidation or corrosion. Incoloy 800 "is capable of remaining stable and maintaining its austenitic structure even after long time exposures to high temperatures". Nichrome is used as resistance wire for heating elements in things like toasters and space heaters. These uses make chromium a strategic material. Consequently, during World War II , U.S. road engineers were instructed to avoid chromium in yellow road paint, as it "may become a critical material during the emergency." The United Stated likewise considered chromium "essential for the German war industry" and made intense diplomatic efforts to keep it out of the hands of Nazi Germany.
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it was a subject of intense diplomacy
, U.S. road engineers were instructed to avoid chromium in yellow road paint, as it "may become a critical material during the emergency." The United Stated likewise considered chromium "essential for the German war industry" and made intense diplomatic efforts