Download or read book Influence des inclusions de composes du soufre du selenium et du tellure sur la deformabilitie a chaud et les proprietes mecaniques des aciers written by J. Bellot and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence des inclusions de compos s du soufre du s l nium et du tellure sur la d formabilit chaud et les propri t s m caniques des aciers written by Jean Bellot and published by . This book was released on 1972 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence des inclusions de compos s du soufre du s l nium et du tellure sur la d formabilit chaud et les propi t s m chaniques de aciers written by J. Bellot and published by . This book was released on 1972 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Contribution l tude de l influence du soufre et du tellure sur la composition et la formation des inclusions dans les aciers usinabilit am lior e written by Jacques Frey and published by . This book was released on 1975 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dans le but d'élucider les causes de cette influence nocive du tellure sur la forgeabilité des aciers et d'y apporter remède, d'étudier le rôle du tellure sur la globularisation des inclusions, nous avons entrepris une étude du système fer-manganèse-soufre-tellure que nous avons complété par des observations sur des aciers industriels.

Download or read book Preparation of Sulphur Selenium and Tellurium Hexafluorides written by H. R. Gwinn and published by . This book was released on 1950 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Physics of Selenium and Tellurium written by Selenium-Tellurium Development Association and published by Pergamon. This book was released on 1969 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermodynamics of Selenium and Tellurium in Molten Metallurgical Slags and Alloys written by Murray Johnston and published by . This book was released on 2007 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are a number of impurity elements present in sulphide ores that can have a deleterious effect on the properties of the final copper metal product. In this thesis, an equilibrium distribution technique was used to determine the thermodynamic behaviour of selenium and tellurium in molten slags used in copper production. Calcium ferrite based slags and copper or silver alloy were equilibrated in magnesia crucibles at temperatures of 1200 to 1400 °C and oxygen partial pressures of 10-11 to 10-0.68 atm. Under conditions typical of those employed during copper converting, the minor elements were found to enter the slag as negatively charged species. The partitioning of selenium and tellurium to the slag was greatest at high temperature, low oxygen partial pressure and at highest concentration of basic oxide (CaO or BaO). The experimentally derived data were combined with published information to calculate the selenide and telluride capacities of the slag, and also to generate fundamental thermodynamic activity data for selenium and tellurium in the slag phase. It was found that the activity coefficients of selenium and tellurium were independent of their concentration in the slag over the range studied, but were strongly dependent on the temperature, slag chemistry and oxidation state of the slag. Experiments were also designed and carried out to determine what effect the presence of iron oxide and its oxidation state has on the behaviour of selenium in the slag. A series of experiments involving iron oxide additions to a calcium aluminate slag was conducted under increasingly oxidising conditions to assess the effect of total iron on the selenide capacity as the dominant oxidation state of iron in the slag changed. It was shown that at a constant ratio of CaO:Al2O3, the selenide capacity increased with total iron in the slag. However, the effect on the selenide capacity did not appear any more significant as the Fe3+:Fe2+ ratio changed in a particular direction. 4 Another series of experiments was carried out with iron calcium silicate slags to determine the stability of phases within the slag, and how this affected the equilibrium distribution and activity coefficient of selenium in the slag. A number of solid phases were identified and their composition determined by scanning electron microscopy, energy dispersive spectroscopy and electron microprobe analysis. The composition and minor element content of the remaining liquid was calculated using a thermodynamic model. From this it was found that the capacity of the liquid slag has a region of independence against slag chemistry, before increasing strongly with increasing lime content to the calcium ferrite composition. Some of the implications of this work are discussed with reference to the practicality of adjusting the process variables in a large-scale industrial process for the purpose of managing minor element content of the molten phases. Considerations include the effect on copper recovery and rate of wear of furnace refractory materials.

Download or read book Influence du tellure sur les propri t s de l acier written by Gaston Lanvin and published by . This book was released on 1965 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Physics of Selenium and Tellurium written by and published by . This book was released on 1979 with total page 281 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence de la composition chimique sur la formation de la microstructure et les caract ristiques m caniques de soudures en aciers emboutissables chaud written by Qingdong Yin and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: La thèse porte sur deux aciers emboutissables à chaud, soudés en configuration homogène ou hétérogène en termes de composition chimique et d'épaisseur. Les solutions en flans raboutés laser présentent en effet de remarquables performances à l'impact et connaissent un fort développement dans le contexte actuel de l'industrie automobile (réduction des émissions de CO2 et amélioration de la sécurité passive des véhicules). L'opération de soudage laser peut générer une hétérogénéité de la jonction soudée, due au mélange imparfait des deux matériaux et des conditions thermiques de solidification et d'emboutissage à chaud. Les propriétés mécaniques du joint soudé sont donc déterminées par la qualité du mélange, la composition chimique locale et le cycle thermique.La première partie de l'étude est consacrée à la quantification de l'hétérogénéité du joint soudé et la compréhension de la microstructure. Une nouvelle méthodologie a été développée pour étudier le comportement métallurgique et mécanique de ces joints hétérogènes, en élaborant des coulées synthétiques représentant les différentes compositions chimiques attendues dans le joint réel. Le comportement du joint soudé est reconstruit à partir des données obtenues par la caractérisation de ces coulées synthétiques. La deuxième partie de l'étude porte sur la compréhension de la formation de la microstructure de la zone fondue avant et après traitement thermomécanique simulant l'emboutissage à chaud. Des modèles quantitatifs ont été établis pour calculer les températures de changement de phase, les proportions relatives des constituants microstructuraux ainsi que la dureté de ces alliages en fonction de la composition chimique et du cycle thermique. La dernière partie de l'étude porte sur le comportement mécanique après traitement thermique. Des lois de comportement des matériaux synthétiques ont été déterminées en fonction de leur composition chimique et du cycle thermique. La sensibilité à la rupture fragile par clivage a été évaluée par des essais de traction sur éprouvettes sévèrement entaillées. Les lois de comportement obtenues ont été appliquées pour déterminer la tolérance du joint soudé à un défaut géométrique, sous sollicitation de traction uniaxiale.