Language: RUS ENG Partner's office Product Catalog Site Map Feedback Company Products Technologies and equipment Metal deoxidation Desulfurization of metal Microalloying metal Metal modification Science Center Press center Contacts Metal deoxidation Deoxidation is called lowering the oxygen content in a metal or binding it into strong compounds. The most common deoxidation method is deep ( sedimentary). It is used in metal smelting in all steelmaking units and is carried out by introducing elements into the metal that bind oxygen into strong oxides More or less complete removal of the formed oxide inclusions ( deoxidation products) occurs as a result of their deposition - floating up or removal by the metal flow and transition to slag or to solid interfacial surfaces. At present, aluminum is used in metallurgy for deoxidation of most steels in various forms - in the form of wire or bars. The use of aluminum makes it possible to obtain steel with fine grain and plasticity and toughness indicators that lie within the permissible values. At the same time, the use of aluminum, even with the relative purity of steel, in the future can lead to the appearance of some negative factors: Decrease in the degree of fluidity of steel and, as a consequence, an increase in the likelihood of tightening the channels of the steel nozzles; Possibility of formation of crystalline inclusions of aluminum oxides having an acute-angled shape and serving as sources of destructive stresses ( stress concentrators). When processing aluminum-deoxidized steel with a flux-cored wire with a calcium-containing filler, these negative phenomena are largely less pronounced or their appearance is completely excluded. Calcium treatment of steel preliminarily deoxidized with aluminum makes it possible to achieve oxygen contents that are comparable in magnitude to the equilibrium value with aluminum. Reducing the concentration of oxygen in the processing unit " ladle-furnace" is a source of reducing the amount of non-metallic inclusions during cooling and subsequent solidification of the steel. It is generally known that when processing steel with a wire with a filler containing calcium, at a consumption of the latter not exceeding 0.2 kg / t, it is possible to achieve a decrease in the oxygen content down to thousandths of a percent, which is clearly seen in the presented graph. Change in oxygen content with increasing consumption of flux-cored wire При этом, эффективность работы Ca при раскислении зависит от формы его существования в проволоке: металлический кальций имеет температуру плавления 851 °С и температуру испарения 1492 °С, температура плавления наиболее распространенного ферросплава СК30 (30% Ca и 60 Si по ГОСТ 4762-71) составляет 1100 °С, данный материал имеет меньшую упругость паров, что приводит к большей эффективности работы Ca. При установленной скорости введения порошковой проволоки обеспечивается усвоение кальция свыше 20%. Одной из самых важных задач при производстве стали, предварительно раскисленной алюминием, является исключение вероятности затягивания каналов сталеразливочных стаканов при непрерывной разливке металла. Это обеспечивается регламентированным вводом порошковой проволоки с кальцийсодержащим наполнителем в ковш на агрегате «ковш-печь» в количествах, зависящих от содержания Al, Si, O, S в жидком металле. Зависимость степени раскисления от времени обработки Преимущества, выраженные в уменьшении содержания кислорода в металле при раскислении порошковой проволокой по сравнению с обработкой кусковыми материалами ясно видны на представленном ниже графике зависимости содержания кислорода в стали от времени обработки. Ekaterina Iskhakova Consultant Ask a Question CJSC " Ferrosplav", founded in 1993, is one of the leading enterprises in the CIS, producing flux-cored wire for out-of-furnace processing of cast iron and steel, fractionated and briquetted ferroalloys. More → Ferrosplav, JSC st. Sulimova, 75 , Chelyabinsk Phone: (351) 261-88-78 Site created in Design Bureau with the assistance of Studio Luch About the site Site Map Contacts Feedback