Not only decarburization, you could also find another pics such as measurement, steel, argon oxygen, surface after heat treat, diagram, press hardened steel, type 2, vacuum oxygen, praxair argon oxygen, imperfections, microstructure, and vd tank. Electric arc furnaces and argon oxygen decarburization vessels were proposed on october 21, 1974, promulgated on september 23, 1975, and mostrecently amended on february 22, 2005. Argon oxygen decarburization, frequently referred to as aod, is an advanced technology for the refinement of iron, nickel, and cobalt based alloys. Argon oxygen decarburization aod treatment is the recognized standard for stainless steel refining worldwide. Eaf followed by refining by argon oxygen decarburization aod to adjust the carbon content and remove impurities. Resourcesaving operation of stainless steel refining in vod and. Argon is colorless, odorless, nonflammable and nontoxic as a solid, liquid or gas.
Download fulltext pdf simulation of fluid flow and oscillation of the argon oxygen decarburization aod process article pdf available in metallurgical and materials transactions b 412. Pdf the oscillation of argon oxygen decarburization aod converters is flow related and depends on the process parameters e. 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. Argon oxygen decarburization aod converter is popularly used in the stainless steel making process. This file is licensed under the creative commons attributionshare alike 2. Subsequently, the liquid passes to the converter, within which the steel undergoes the refining chemical analysis through redox reactions. In the aod process, steel from the eaf is transferred into an aod vessel and gaseous mixtures containing argon and oxygen or. Optimization of the ao stainless steel processing cost by the ut as system chay tauar 800521t290 the argon oxygen decarburization aod process is one of the major stainless steel refining routes. In the argon oxygen decarburization process, a mixture of oxygen and argon gas is injected into the liquid steel. Carbon from the interior diffuses towards the surface, moving from high to low concentration and continues until the maximum depth of decarburization is established. Some available mathematical models for the argonoxygen decarburization aod stainless steelmaking process have.
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. In the aod process, steel from the eaf is transferred into an aod vessel and gaseous mixtures containing argon and. After initial melting the metal is then transferred to an aod vessel where it will be subjected to three steps of refining. Alternative, melting and refining steps include vacuum induction melting, vacuum arc remelting, electroslag remelting, and electron beam melting. 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. Aod production argon oxygen decarburization in this process the merger is implemented in conventional furnace. A decarburization process based on a stepwise decrease of the oxygen to inert ratio according to table 1 was gradually established. This argon dilution minimizes unwanted oxidation of precious elements contained in specialty steels, such as chromium. Since stainless steels need to be further refined, oxygen, gradually replaced by argon, is blown through the molten steel to eliminate impurities. Vodvacuum oxygen decarburization aod argon oxygen decarburization vodvacuum oxygen decarburization. You may do so in any reasonable manner, but not in.
It brings the tightest chemistry control to deliver the highest levels of metal purity. Today, over 75% of the worlds stainless steel is made using the argon oxygen decarburization aod process invented by praxair. Invented in the late 1960s, praxair s proprietary argon oxygen decarburization aod process was first used exclusively for stainless steel production. Argon oxygen decarburization furnace steel slag aod mineralproducts1. Physical and mathematical modeling of the argonoxygen decarburization refining process of stainless steel. Argonoxygen decarburization aod what a process for further refinement of stainless steel through reduction of carbon content. Metal refining with argon oxygen decarburization aod refining systems allow precise gas manipulation to achieve the desired end result. Chemical analysis of argonoxygen decarburization slags in.
Pdf simulation of fluid flow and oscillation of the. Aod provides an economical way to produce stainless steel with a. Recovery of valuable metals from argon oxygen decarburization. Pdf simulation of fluid flow and oscillation of the argon oxygen.
Argon oxygen decarburization aod converter slags are known to consist of both liquid and solid phases, but limited information on the slag characteristics has been published in the open literature. Argon oxygen decarburization aod is used during the refining process to produce steel with low. Several parameters come into play deciding the outcome of the. In this process the tuyeres are submerged, resulting in high element recovery, rapid and efficient desulfurization, and good control of the slag chemistry. Argon oxygen decarburization aod is a process primarily used in stainless steel making and. The process of deep decarburization of steel during argon or hydrogen argon mixture injection has been studied. This process permits the production of high chromium steels and alloys in a technically and commercially advantageous way extremely low carbon contents together with high chromium recovery, with minimal consumption. Mathematical modeling of the argonoxygen decarburization refining. Physical and mathematical modeling of the argonoxygen. At higher temperatures, the diffusion rate of carbon is so large that longer annealing times lead to decarburization. Mathematical modeling of the argonoxygen decarburization refining process of stainless steel. Optimization of the ao stainless steel processing cost by. D this process is mainly used for making stainless steel only of 304l, 316l grade to achieve extra low carbon content in stainless steel.
Figure 1 shows a typical vod stainless steel production furnace. Ladle service under the conditions of vacuumoxygen. 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. By using only eaf for the production of stainless steel the following difficulties were arise. Carbonation of argon oxygen decarburization stainless steel slag and its effect on chromium leachability. The argon oxygen decarburization aod process is used to make stainless steel and specialty grades of steel, including tool steels, silicon steels, lowalloy steels, and lowcarbon steels. The new source performance standards nsps for steel plants. This page was decarburisation edited on 4 octoberat during the final stage of blowing, the ratio of oxygen to argon is changed to 1. 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. The argon oxygen decarburisation aod and the vacuum oxygen decarburisation vod processes are the. Decarburization or decarbonization is the process opposite to carburization, namely the reduction of carbon content the term is typically used in metallurgy, describing the reduction of the content of carbon in metals usually steel.
Unlimited viewing of the articlechapter pdf and any associated. This work led to the first commercial aod installation in joslyn, usa 1968 1. Modeling of gas flows in steelmaking decarburization. Recovery of valuable metals from argon oxygen decarburization aod dusts by. Desulphurization to very low levels is generally easier in dolomitic refractories because very basic slags can be used without detrimental effects on the bricks. An argon oxygen decarburization aod refining method for molten austenitic stainless steel. Argon oxygen decarburization for metal production praxair, inc. Author links open overlay panel yajun wang a b yanan zeng b junguo li b yuzhu zhang a b yajing zhang c qingzhong zhao b. Argon is chemically inert under most conditions and forms no confirmed stable compounds at room temperature although argon is a noble gas, it can form some compounds under various extreme conditions. Chemical analysis of argon oxygen decarburization slags in stainless steelmaking process by x.
In the argonoxygen decarburization process, a mixture of oxygen and argon gas is injected into the liquid steel. Melting and refining of stainless steels is, however, most frequently. Decarburization basics arburization occurs when cardec bon atoms at the steel surface interact with the furnace atmosphere and are removed from the steel as a gaseous phase18. View the article pdf and any associated supplements and figures for a period of 48 hours. By varying the ratio of oxygen and argon, it is possible to remove carbon to controlled levels by oxidizing it to carbon monoxide without also oxidizing and losing expensive. Argon oxygen decarburization furnace steel slag aod. Ladle service under the conditions of vacuum oxygen decarburization 187 a were mainly wom in the slag line. Product center success case project gallery download recruitment. Aod, argon oxygen decarburization, is a process for making stainless steel and other high grade alloys by allowing precise gas manipulation. Argon oxygen decarburization, frequently referred to as aod, is an advanced technology. Argon has approximately the same solubility in water as oxygen and is 2. The erosion of this zone amounted to 20 mm per heat.
Learn more about praxairs argon oxygen decarburization process that is used to make over 75% of the worlds stainless steel. Carbonation of argon oxygen decarburization stainless. After 3 4 heats, through slots formed in the joints of the bricks as well as ovalshaped washouts through which the metal leaked between the functional and the intermediate layer. Metal refining with argon oxygen decarburization aod. 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. The key feature in the aod vessel is that oxygen for decarburization is mixed with argon or nitrogen inert gases and injected through submerged tuyeres. The argon oxygen decarburization process total materia. Vcvacuum casting device steelmaking dedusting ironmaking dedusting material handling dedusting dedusting facilitie. Needs very high temperatures about 19000 c for decarburization requiring high cost refractories. This introduction causes significant agitation and, therefore, intimate slagmetal contact.
Blowing argon and oxygen, using sheets, maintain a continuous mixing. Decarburization is a loss of carbon in the surfaceadjacent zone of the material gunnarson, 1963. Contributing factors are high temperatures and large amounts of oxygen in the atmosphere. Why the amount of carbon in stainless steel must be lower than that in carbon steel or lower alloy steel i. Introduction to stainless steels asm international. Argon oxygen decarburization converter manufacturer from. Two industrial vod nozzles were numerically studied and compared at different temperatures and ambient pressures. Mathematical modeling of the argon oxygen decarburization. Argon oxygen decarburization aod is a process primarily used in stainless steelmaking and other high grade alloys with oxidizable elements such as chromium and aluminum. 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.613 660 704 1044 702 626 91 188 929 966 1458 116 1394 626 1157 964 587 740 1035 874 1251 205 775 170 336 1521 931 1298 25 1246 454 838 778 1306 529 172 758 828 1008 1176 170 598 1438 1079 1335