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Orichalcum or aurichalcum / ˌ ɔːr ɪ ˈ k æ l k ə m / is a metal mentioned in several ancient writings, including the story of Atlantis in the Critias of Plato.Within the dialogue, Critias (460–403 BC) says that orichalcum had been considered second only to gold in value and had been found and mined in many parts of Atlantis in ancient times, but that by Critias's own time, orichalcum ...
Because tungsten is a rare metal [134] and its compounds are generally inert, the effects of tungsten on the environment are limited. [135] The abundance of tungsten in the Earth's crust is thought to be about 1.5 parts per million. It is the 58th most abundant element found on Earth. [136]
The Earth's crust is one "reservoir" for measurements of abundance. A reservoir is any large body to be studied as unit, like the ocean, atmosphere, mantle or crust. Different reservoirs may have different relative amounts of each element due to different chemical or mechanical processes involved in the creation of the reservoir.
Wootz steel is a crucible steel characterized by a pattern of bands and high carbon content. These bands are formed by sheets of microscopic carbides within a tempered martensite or pearlite matrix in higher- carbon steel , or by ferrite and pearlite banding in lower-carbon steels.
Evidence of the production of crucible steel have been found in Merv, Turkmenistan, a major city on the 'Silk Road'. The Islamic scholar al-Kindi (801–866 CE) mentions that during the ninth century CE the region of Khorasan, the area to which the cities Nishapur, Merv, Herat and Balkh belong, was a steel manufacturing centre. [44]
As more steel is produced than is scrapped, the amount of recycled raw materials is about 40% of the total of steel produced – in 2016, 1,628,000,000 tonnes (1.602 × 10 9 long tons; 1.795 × 10 9 short tons) of crude steel was produced globally, with 630,000,000 tonnes (620,000,000 long tons; 690,000,000 short tons) recycled.
These values decrease with increased load, settling at around 28 GPa each. The nanoindentation values were found to be 36.4 GPa and 34.0 GPa for the (002) and perpendicular planes respectively. The hardness values depend on the material purity and composition – the more boron the harder the boride – and the above values are for a Re:B ratio ...
Low-background steel, also known as pre-war steel [1] and pre-atomic steel, [2] is any steel produced prior to the detonation of the first nuclear bombs in the 1940s and 1950s. Typically sourced from ships (either as part of regular scrapping or shipwrecks ) and other steel artifacts of this era, it is often used for modern particle detectors ...