What are the advantages of using argon in AOD process for decarburization?
What are the advantages of using argon in AOD process for decarburization?
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. This argon dilution minimizes unwanted oxidation of precious elements contained in specialty steels, such as chromium.
What is AOD and VOD?
The argon oxygen decarburisation (AOD) and the vacuum oxygen decarburisation (VOD) processes are the dominant methods for refining stainless steels with low carbon contents.
What is the engineering aspect of AOD?
The AOD Process Silicon and aluminum are added to remove more valuable metals from their oxides, resulting in a near 100% recovery. The chemical removal of other gases allows alloying additions of nitrogen in the molten bath.
What is AOD in steel making process?
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. It brings the tightest chemistry control to deliver the highest levels of metal purity.
Why is argon introduced in metallurgical process?
In ladle metallurgy, argon is injected to stir the metal and help facilitate the refining steps. In some cases, argon may also be used as a carrier gas for additions. In the vacuum degassing process, argon is injected into the uplifting snorkel to facilitate metal circulation and degassing.
How is argon refined?
Argon is industrially extracted from liquid air in a cryogenic air separation unit by means of fractional distillation. When nitrogen gas present in the atmosphere is heated using hot calcium or magnesium, a nitride is formed leaving behind small amount of argon as an impurity.
Why decarburization is done?
The effect of decarburization not only brings down the strength, but also increases the shear strain below the metal surface. The fatigue resistance is decreased while the rate of crack growth and wear rate is increased.
What is ladle furnace?
A ladle furnace is composed by a three-electrode electric system, operating AC mode; working into a three-phase electrical circuit, usually placed on the vertices of an equilateral triangle in around the furnace.
What is AOD stand for?
AOD
| Acronym | Definition |
|---|---|
| AOD | Advanced Optical Disc (blue laser based storage technology) |
| AOD | AMD (Advanced Micro Devices, Inc.) OverDrive |
| AOD | Always-On Display (smartphones; Samsung) |
| AOD | Alcohol and Other Drugs |
How does an AOD work?
AOD process uses dilution technique for the decarburization of steel bath. The injection of inert gas (argon or nitrogen) lowers the partial pressure of CO in the bath, thus allowing higher chromium content to be in equilibrium with lower carbon contents.
What is the share of argon in the open air?
Occurrence. Argon constitutes 0.934% by volume and 1.288% by mass of the Earth’s atmosphere.
Which gas is used in metallurgy?
Nitrogen is used for protection of ferrous and non-ferrous metals during annealing, neutral tempering, cyanidation, hard brazing, metal powder sintering. Oxygen is used for boosting burning temperature in furnaces.
