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Steel is an alloy composed of between 0.2 and 2.0 percent carbon, with the balance being iron. From prehistory through the creation of the blast furnace, iron was produced from iron ore as wrought iron, 99.82–100 percent Fe, and the process of making steel involved adding carbon to iron, usually in a serendipitous manner, in the forge, or via the cementation process.
Iron and steel artefacts, including high-carbon steel, were manufactured in northern Sweden, Finland and Norway (in the Cap of the North) from c. 200–50 BC. [ 59 ] [ 68 ] The production of ultrahigh carbon steel is attested at the Germanic site of Heeten in the Netherlands from the 2nd to 4th/5th centuries AD, in the Late Roman Iron Age .
Consequently, at the temperatures needed to reduce zinc oxide to the metal, the metal is already gaseous. [23] [24] Arsenic sublimes at 615 °C (1137 °F), passing directly from the solid state to the gaseous state. [21] Antimony melts at 631 °C (1167 °F) [21] Platinum melts at 1768 °C (3215 °F), even higher than iron. [21]
To inhibit corrosion, at least 11% chromium can be added to steel so that a hard oxide forms on the metal surface; this is known as stainless steel. Tungsten slows the formation of cementite , keeping carbon in the iron matrix and allowing martensite to preferentially form at slower quench rates, resulting in high-speed steel .
The use of cork, which has been recently added to the category of materials science, had its first mentions beginning with Horace, Pliny, and Plutarch. [10] It had many uses in antiquity including in fishing and safety devices because of its buoyancy, an engraving medium, sandal soles to increase stature, container stoppers, and being an insulator.
In this system, high-purity wrought iron, charcoal, and glass were mixed in crucibles and heated until the iron melted and absorbed the carbon. The resulting high-carbon steel, called fūlāḏ by the Arabs (Arabic: فولاذ, romanized: fūlāḏ, lit. 'steel; wootz') and wootz by later Europeans, was exported throughout much of Asia and Europe.
Steel is made from iron and carbon. Cast iron is a hard, brittle material that is difficult to work, whereas steel is malleable, relatively easily formed and versatile. On its own, iron is not strong, but a low concentration of carbon – less than 1 percent, depending on the kind of steel – gives steel strength and other important properties.
The chemical elements can be broadly divided into metals, metalloids, and nonmetals according to their shared physical and chemical properties.All elemental metals have a shiny appearance (at least when freshly polished); are good conductors of heat and electricity; form alloys with other metallic elements; and have at least one basic oxide.