Effects of impurities on graphite shape during solidification of spheroidal graphite cast ions

International audienceSince the discovery that magnesium and cerium (and more generally rare earths) added at low level to cast iron melts lead to spherodized graphite, it is known that some other elements are detrimental even when present as traces. In all practicality, it has soon been recognized that adding rare earths to the melt helps counteracting the effect of these detrimental elements. Accordingly, only few works have been devoted to studying the effect of trace elements in melts without any rare earths. This is the first aim of the present work to review those studies as they contain the material to understand the mechanism for spheroidal graphite degeneracy. From this review, three types of degeneracy have been defined which show up when the critical level of any particular element is exceeded. These results are then discussed to show that all degeneracies certainly proceed in the same way. To substantiate this discussion, the growth of compacted graphite as obtained by low level treatment of cast iron melt with magnesium is also presented. Finally, a mechanism is suggested for describing the action of trace elements on spheroidal graphite degeneracy. This mechanism is partly substantiated by first-principles calculations which showed that all elements can strongly adsorb on the prismatic planes which are the planes on which carbon atoms add on during graphite growth

O impasse libanês

O impasse libanê

Carte generale de l'empire de Russie

I. Condet sc.Stecher und Jahr im Kartenrahmen unten links2 Erläuterungskartuschen (lat./franz.)und Massstabsleiste unten linksMassstab in graphischer Form (Echelle, Werstes)Ursprungswerk: Atlas Nouveau par Guillaume de L'Isle ; 65/6

Plan des differents camps du Vicomte de Turenne & du Comte de Montecuculli dans l'Ortnaw en l'année 1675 / G. Kondet fecit. ; C. Kondet scrip.

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Hemisphere Occidental [cartographic material] : dresse en 1720 pour L'usage particulier du Roy ... dans les memoires de L'Academie R[oya]le des Sciences /

Assumed coastline of N.W. America.; Hemispherical map of the Americas and Pacific, with political boundaries, and tracks of voyages of discovery to 1710. Relief shown pictorially.Also shows forts, and Terre Australie du S. Esprit.; Ligne de demarcation selon La Bulle d'Alexandre VII.; Probably pl. 5 from : Atlas nouveau, contenant toutes les partes du monde./ Delisle, G. Amsterdam, Covens & Mortier, 1741?; Phillips, 596.; Rex Nan Kivell Collection Map NK 1565

Étude DIAPRHEG 1 (identification des signes précoces de l'hémochromatose par la méthode qualitative)

PARIS7-Xavier Bichat (751182101) / SudocSudocFranceF

La prise en charge des handicaps chez les grands vieillards en Afrique.

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Etude francophone du très Grand Age en Afrique.

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Royaume de Corée / [d'Anville] ; C. Kondet scrip., fecit.

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Carte des pays traversés par le Cap. Beerings depuis la ville de Tobolsk jusqu'à Kamtschatka / [d'Anville] ; G. Kondet fecit et scrip.

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