What is VOD and AOD?

What is VOD and AOD?

AOD and VOD processes elaborate stainless steels from either of two basic production cycles. They are originate from iron ore and steel scrap respectively.

What does AOD stand for in steel making?

Steeling the lead. Today, over 75\% of the world’s stainless steel is made using the Argon Oxygen Decarburization (AOD) process invented by Linde. AOD provides an economical way to produce stainless steel with a minimal loss of precious elements.

What is VOD in steel making process?

Vacuum Oxygen Decarburizing (VOD) is typically used to produce stainless steels. In comparison to the VD process, VOD treatment involves an additional oxygen blowing step to reduce the steels content of oxidizable compounds as e.g. carbon or phosphor.

What is AOD in foundry?

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.

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.

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 AOD slag?

AOD slag is generated during the refining process step. It naturally falls to a powder on cooling but can be stabilised, producing a solid crystalline slag. Today, stainless steel slag recovery as aggregates in concrete is increasingly considered.

What is the difference between primary and secondary steel?

Primary steelmaking uses a blower to force oxygen through molten iron, whereas secondary steelmaking is characterized by the use of an electric arc. It simply blows oxygen through the molten iron. Although it’s most commonly performed with scrap iron, secondary steelmaking can produce large yields of steel.

What is ladle in steel plant?

In metallurgy, a ladle is a vessel used to transport and pour out molten metals. Ladles are often used in foundries and range in size from small hand carried vessels that resemble a kitchen ladle and hold 20 kilograms (44 lb) to large steelmill ladles that hold up to 300 tonnes (295 long tons; 331 short tons).

Why is argon used in the manufacture of steel?

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.

Why is argon used in production of steel?

steelmaking. In the argon-oxygen decarburization process, a mixture of oxygen and argon gas is injected into the liquid steel. 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…

What is Decarb layer?

Decarburization (or decarbonization) is the process opposite to carburization, namely the decrease of the carbon content. The term is typically used in metallurgy, describing the decrease of the content of carbon in metals (usually steel).

What is the difference between AOD and VOD process?

Now the difference between these two process comes into the picture. In VOD partial pressure of CO is reduced with the help of vacuum and in AOD partial pressure of CO reduced with the help of Argon but ultimately both the refining processes are based on Le Chatlier’s principle only. , Practical Metallurgist!!!!!

What is AOD stainless steel?

AOD was invented in 1954 by the Lindé division of The Union Carbide Corporation, which became Praxair in 1992. Today, over 75 \% of the world’s stainless steel is made using the AOD process.

What does AOD stand for?

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. After initial melting the metal is then transferred to an AOD vessel where it will be subjected to three steps of refining; decarburization,…

What is argon oxygen decarburization (AOD)?

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. After initial melting the metal is then transferred to an AOD vessel where it will be subjected to three steps of refining; decarburization, reduction, and desulfurization .