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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Decarburization occurs when dissolved carbon reduces the chromium and iron oxides that form. The installation of a lance and introduction of oxygen in the early stages of decarburization can reduce the time for a heat. Typical internal volumes of AOD converters are in the range 0. Since the AOD vessel isn’t externally heated, the blowing stages are also used for temperature control.
These are achieved argon-oxygem having a high lime concentration in the slag and a low oxygen activity in the metal bath. The process is very popular because it combines higher metallic yields with lower material costs.
At any given time, one of the converters is in the tiltable trunnion ring refining steel, a second newly lined converter is at a preheating station, and the third converter is at a reline station. This is argin-oxygen in a ladle equipped with stirring facilities with or without the use of a argon-oxyen furnace.
This argon dilution of oxygen minimizes unwanted oxidation of precious elements contained in specialty steels, such as chromium.
Argon-oxygen decarburization | metallurgy |
History of ferrous metallurgy List of steel producers. In the early days of the AOD process, the converter was tilted for raw material additions as well as for taking samples and for measurement of temperature using immersion thermocouples. This article needs additional citations for verification. The intimate gas — aargon-oxygen contact and excellent slag — metal mixing facilitate refining reactions.
Donate Grateful for your donation! Unsourced material may be challenged and removed. The amount of stirring energy from the gas blown through the subsurface tuyeres and the formation of the carbon monoxide deep within the metal bath results in the converter processes being among decarbueization most intensely stirred metallurgical reactors.
An AOD converter is shown in Fig 1. During the final stage of blowing, the ratio of oxygen to argon is changed to 1: If the grade argo-noxygen be produced requires an extra low sulphur level, the bath is deslagged after the reduction step and another basic slag is added.
Argon oxygen decarburization for metal production
Desulphurization is achieved by having a high lime concentration in the slag and a low oxygen activity in the metal bath. The bath is then stirred with inert gas, typically for around five to eight minutes. It has a removable, conical cover in place.
Additions of lime are made to dilute the sulphur in the liquid steel bath. Converters are typically zoned by thickness and brick quality to maximize lining life and minimize costs. There are usually between two and nine decarburizatikn in an AOD vessel.
The next step is the reduction step, in which the reduction additions are charged and stirred with an inert gas for a desired time. Want to modernize and upgrade the functionality of your old AOD system cost-effectively? The important feature of an AOD converter is that it is normally side blown.
Your email address will not be published. Phosphorus, which requires oxidizing conditions, cannot be removed in the converter processing.