The oscillation of argon oxygen decarburization aod converters is flow related and depends on the process parameters e. The argon oxygen decarburization process total materia. Optimization of the ao stainless steel processing cost by the. Jul 10, 2017 argon oxygen decarburization aod is a process primarily used in production of stainless steel and other high grade alloys such as silicon steels, tool steels, nickelbase alloys and cobaltbase. Multilayer perceptron to model the decarburization process in.
The aod process argon, oxygen, decarburization is the first production process for stainless steel grades in which the treatment time in a converter under atmospheric conditions corresponds to the casting time of a slab caster for many steel grades. During the decarburization step the vacuum system must be able to operate continuously at a rough pressure in the range of 50200 mbar, while simultaneously removing high gas flows of. Silicon and aluminum are added to remove more valuable metals from their oxides, resulting in a near 100% recovery. Theoretical models have been developed for an argon oxygen decarburization aod converter that also incorporated a thermodynamic description of the process 238. During the stainlesssteel smelting process, a certain amount of chromium in the molten steel can be oxidized due to oxygen decarburization, and chromiumcontaining sss is produced. By loading the furnace charge into the aod vessel the impurities in the charge can be significantly reduced and at the same time improvements can be made relating to the properties of the. Cementitious behavior of argon oxygen decarburization. Learn more about praxairs argon oxygen decarburization process that is used to make over 75% of the worlds stainless steel.
In the argon oxygen process, the bath of molten steel receives simultaneous injections of argon or nitrogen and oxygen for decarburization of the melt. Aod has a top lance for oxygen injection and several. Argon oxygen decarburization treatment aod whiting. Nov 30, 2020 through the management of an additional high oxygen partial pressure gas mix and argon, the metal is refined and can reduce carbon levels to 0. Optimization of the ao stainless steel processing cost by. Argon oxygen decarburization, frequently referred to as aod, is an advanced technology for the refinement of iron, nickel, and cobalt based alloys. In the argon oxygen decarburization process, a mixture of oxygen and argon gas is injected into the liquid steel.
Jul 15, 2020 argon oxygen decarburization process pdf july 15, 2020 0 learn more about praxairs argon oxygen decarburization process that is used to make over 75% of the worlds stainless steel. Today, over 75% of the worlds stainless steel is made using the argon oxygen decarburization aod process invented by praxair. After initial melting the metal is then transferred to an aod vessel where it will be subjected to three steps of refining. High costs for vacuum generation and maintenance can be overcome by replacing steam ejector pumps with mechanical vacuum pumps, initially for the vacuum degassing vd process but later also for the vacuum oxygen decarburization vod process. Argon oxygen decarburization aod is a process primarily used in stainless steel making and other high grade alloys with oxidizable elements such as. Argon oxygen decarburization for metal production linde. Argon oxygen decarburization furnace steel slag aod youtube. Duplex process of steel melting at foundry 1 of jsc armaprom hd eng. Argon recovery from argon oxygen decarburization process waste gases download pdf info publication number us5220797a.
The oxygen flow can also be used for chemical heating of the melt vdob process, as the chemical reactions of the steel contents with oxygen are exothermic. Us5220797a argon recovery from argonoxygendecarburization. Argon oxygen decarburization aod converter is popularly used in the stainless steel making process. Aug 08, 2019 electroslag remelting vacuum arc remelting argon oxygen decarburization. It brings the tightest chemistry control to deliver the highest levels of metal purity. Simulation of fluid flow and oscillation of the argon oxygen. Chemical analysis of argonoxygen decarburization slags in. Show full abstract coupled with a new simulator concept for the aod process, argon oxygen decarburization.
After a successful validation, the same approach was used to model chemical reactions. Jan 14, 2020 argon oxygen decarburization process pdf posted on january 14, 2020 by admin learn more about praxairs argon oxygen decarburization process that is used to make over 75% of the worlds stainless steel. In the beginning of the aod process, pure oxygen is blown and silicon and carbon are oxidizing. Vacuum oxygen decarburization metallurgy britannica. Argon oxygen decarburization aod is a process primarily used in production of stainless steel and other high grade alloys such as silicon steels. The decarburization in an aod converter is made in a series of steps with distinct oxygen inert gas ratio, which is progressively decreased with increasing decarburization. A mathematical fluid flow model of gas injection in an argonoxygen decarburisation aod converter process has been coupled with a high temperature. The task focuses on studying an optimized processing in an aod converter using the uhts converter automation system utcasprocess control program. Refer to pn 414 regarding single melt and remelt stainless steel.
In the aod process, steel from the eaf is transferred into an aod vessel and gaseous mixtures containing argon and oxygen or. It is reported that the carbon removal efficiency in argon oxygen decarburization process aod was improved by using co 2 argon oxygen mixtures. The task focuses on studying an optimized processing in an aod converter using the uhts converter automation system utcas process control program. Chromium is mainly trivalent in ssss, but it can be converted to crvi and released into the environment under suitable conditions. Resco products has been and is involved in this application with its ability to supply both dolomitic as well as magnesite chrome refractory products. Argon oxygen decarburization aod vacuum degrassing vacuum oxygen decarburization vod ruhrstahl heraeus rh variable pressure inlet introduction in 20, over 1.
Djustmentofchemicalcomposition aod the argon oxygen decarburization aod unit is used for extensive decarburiation of the melt. What is called argon oxygen decarburization aod process. Mathematical modeling of the argonoxygen decarburization refining. Argon oxygen decarburization furnace steel slag aod. The present invention is directed to a method for recovering argon from a feed mixture comprising argon, carbon monoxide, carbon dioxide, nitrogen, and hydrogen which comprises the steps of a purifying the feed mixture to remove contaminants, b compressing the purified feed mixture to a separation pressure, and c passing the compressed purified feed mixture through a pressure swing. Argon oxygen decarburization aod is used during the refining process to produce steel with low carbon properties and low silicon levels, while creating a metal more weldable and more corrosion and heat resistant. Aod process argon oxygen decarburization, for the removal of carbon and of sulphur stainless steelwikipedia. Pdf simulation of fluid flow and oscillation of the argon oxygen. Jan 26, 2010 the oscillation of argon oxygen decarburization aod converters is flow related and depends on the process parameters e. The aod process argon, oxygen, decarburization is the first production process for stainless steel grades in which the treatment time in a converter under. Pdf simulation of fluid flow and oscillation of the.
Argonoxygen decarburization aod magnesia chrome and. Argonoxygen decarburization aod is the most dominant process for the generation of stainless, lowalloy, and superalloy steels. Co 2 is also possible to be used in converter process to produce medium and low carbon ferrochrome in ferroalloy industry. The aod process became very popular because it created a more economical way to produce specialty steels. Two industrial vod nozzles were numerically studied and compared at different temperatures and ambient pressures. For a 120ton aod converter with seven submerged sidewall nozzles, plant tests, physical simulations on a. Co 2 is also possible to be used in converter process to produce medium and low carbon ferrochrome in ferroalloy industry 3. The argon oxygen decarburization aod is the refining process of stainless steel to get its final chemical composition through several stages, where tons of materials are added and oxygen and inert gas are blown.
In the aod process, steel from the eaf is transferred into an aod vessel and gaseous mixtures containing argon and oxygen or nitrogen are blown into the vessel to reduce the carbon. Aod provides an economical way to produce stainless steel with a minimal loss of precious elements. Some authors 58 also carried out the study on the surface. Jun 10, 2019 argon oxygen decarburization aod treatment is the recognized standard for stainless steel refining worldwide. Modeling of the vacuum oxygen decarburization refining process. Argon oxygen decarburization aod is a process primarily used in stainless steel making and other high grade alloys with oxidizable elements such as chromium and aluminum.
It is based on a stepwise comparison of the reaction free energies, and it allows the continuous calculation of the change of the metal, slag, and gas composition throughout the duration of the vod process. Since argon has a cooling effect and oxygen creates heat the temperature of the melt is readily controlled by the amounts of the two gases injected. Several parameters come into play deciding the outcome of the process. Modeling of gas flows in steelmaking decarburization processes. A new method is used to calculate the oxygen distribution in the metalgas reactions. Multilayer perceptron to model the decarburization process. Today, over 75% of the worlds stainless steel is made using the argon oxygen decarburization aod process invented by linde. It is part of a duplex process in which scrap or virgin raw. The vod is often used to lower the carbon content of highalloy steels without also overoxidizing such oxidizable alloying elements as chromium. With the progress of decarburization step, pure oxygen blow is partially replaced by inert gas nitrogen or argon in order to reach lower carbon level and minimize the oxidation of chromium. The argon oxygen decarburization aod process is one of the major. Vacuum oxygen decarburization vod of stainless steel. Pdf simulation of fluid flow and oscillation of the argon. Fundamental decarburisation model of aod process taylor.
Us5125934a argon recovery from argonoxygendecarburization. Evaluation on material and heat balance of eaf processes with. Simulation of fluid flow and oscillation of the argon. Argon oxygen decarburization aod is a process used to further refine the steel outside the eaf during the production of certain stainless and specialty steels. After the transfer of liquid steel containing iron, chromium, carbon and nickel decarburizatikn eaf or if to the aod converter, high carbon ferro chrome is added and the blow is started with the blowing of inert gas argon, nitrogen and oxygen mixture. In the argonoxygen decarburization process, a mixture of oxygen and argon gas is injected into the liquid steel. Aug 31, 2019 argon oxygen decarburization aod treatment is the recognized standard for stainless steel refining worldwide. The aod argon oxygen decarburization refining process is used to produce stainless and highalloyed.
Argon oxygen decarburization aod is a unique refinement process for iron, nickel, and cobalt alloys whereby huge quality and efficiency gains can be made. A dynamic model for the vacuum oxygen decarburization vod refining process is presented. The argon oxygen decarburization aod process is one of the major stainless steel refining routes. Optimization of the aod stainless steel processing cost by. Pdf understanding stainless steelmaking through computational. Sulphur refining is done by using inert gas blowing such as argon or nitrogen in the. Argon recovery from argonoxygendecarburization process waste gases download pdf info publication number us5125934a. The injection of inert gas argon or nitrogen lowers the partial pressure. It is part of a duplex process in which scrap or virgin raw materials are first melted in an electric arc furnace.
Pdf modeling of the vacuum oxygen decarburization refining. Evaluation on material and heat balance of eaf processes. Aod is a refining process which typically follows the initial melting process eaf electric arc furnace. While much of this capacity is still produced in primary steel processes such as bos, bof, lh etc.
Aod process uses dilution technique for the decarburization of steel bath. Improving low carbon steel production in specialty steel. A nonlinear prediction model, incorporating mass transfer. Argon oxygen decarburization aod is a process primarily used in production of stainless steel and other high grade alloys such as silicon steels, tool steels, nickelbase alloys and cobaltbase alloys with oxidizable elements such as chromium and aluminum.
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