ARGON-OXYGEN DECARBURIZATION PDF
Learn more about Praxair’s Argon Oxygen Decarburization process that is used to make over 75% of the world’s stainless steel. Argon Oxygen Decarburization (AOD) Treatment is the recognized standard for stainless steel refining worldwide. Whether you are producing castings, wrought . Argon Oxygen Decarburization, frequently referred to as “AOD”, is an advanced technology for the refinement of iron, nickel, and cobalt based alloys. By.
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At this point, the process gases can be shut off and a small cooling flow protects the tuyeres.
The key feature in the AOD converter is that oxygen for decarburization is mixed with inert gas such as argon or nitrogen and injected through submerged tuyeres. Unsourced material may be challenged and removed. These are i decarburization, ii reduction, and iii final chemistry and temperature trimming. Oxidation of carbon continues, but oxidation of chromium is limited. Converters are typically zoned by thickness and brick quality to maximize lining life and minimize costs.
Depending on final nitrogen specification for the stainless steel grade, the inert gas during the initial stages of decarburization can be nitrogen. Magnesite chromite refractories have high wear resistance but have a higher unit cost cecarburization dolomitic refractories. The effectiveness of reduction step is dependent on many factors including slag basicity and composition, temperature, mixing conditions in the converter and solid addition dissolution kinetics.
Pattern welding Damascus steel Crucible steel Tatara argon-xoygen Cementation process.
The system will be tailored to match your current operation with added features found only on the new systems. Bottom injection usually improves wear characteristics in the barrel section of the converter. After a desired carbon and temperature level have been reached the process moves decarburizatipn reduction. An annulus is formed between the copper and stainless tubes. Refractory costs are a significant fraction of total operating costs.
Ingot (AOD Refining)
Your email address will not be published. For converters that tap into a ladle held by a crane, a sliced cone top section is often used.
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In general, the bath temperature is controlled to less than deg C. The slice portion allows the crane to come close to the converter mouth. The intimate gas — metal contact and excellent slag — metal mixing facilitate refining reactions. After initial melting the metal is then transferred to an AOD vessel where it arbon-oxygen be subjected to three steps of refining; decarburizationreductionand desulphurization.
Argon Oxygen Decarburization for Metal Production | Praxair, Inc.
History of ferrous metallurgy List of steel producers. The molten metal is then decarburized and argon-oxyben in a special AOD vessel to less than 0. During the final stage of blowing, the ratio of oxygen to argon is changed to 1: Process gases are injected through submerged tuyeres that are installed in the side wall or argn-oxygen of the converter. In modern practices a sulphur level of 0. November Learn how and when to remove this template message.
The liquid steel, which contains most of the chromium and nickel needed to meet the final heat composition, is tapped at a temperature of to deg C from the EAF or the IF into a transfer ladle. This page was last edited on 4 Octoberat Desulphurization is achieved by having a high lime concentration in the slag and a low oxygen activity in the metal bath. A major modification of the AOD process involves the use of top blowing lance in addition to the side blowing tuyeres.
Argon Oxygen Decarburization Process |
American inventions Stainless steel Argon-oxyfen. When the vessel is rotated, the tuyeres are above the bath. The liquid metal is transferred from transfer ladle to AOD converter. AOD process refining has three major steps.
In the initial stage, oxygen to argon in the ratio ranging from 5: The AOD converter has tuyeres mounted in the sidewall or in the bottom. Magnesite chromite bricks are simultaneously acidic and basic and strict slag compositions must be maintained to prevent rapid wear.
Would like to more details of how to increase vessel life and to reduce refractory wear near tuyers. After sulfur levels have aegon-oxygen achieved the slag is removed from the AOD vessel and the metal bath is ready for tapping.