1. VD / VOD

VD / VOD

The increasing demand for high quality steel makes the vacuum treatment an essential step in secondary metallurgy process. Tenova Vacuum Degasser units (VD) feature effective removal of hydrogen, oxygen and/or carbon, based on proven technology and experience

Vacuum Degasser (VD) allows to degas and decarburize the melt and provides the best conditions for desulphurization and inclusions removal. During the VD treatment, the liquid steel ladle is placed in a vacuum tank that can be of stationary or movable design according to the specific layout needs. Vacuum condition is achieved with a vacuum pump system, formed by mechanical pumps or steam ejectors. In order to promote stirring, inert gas is injected through porous plugs. VD can be equipped with an additional oxygen lance (VD-OB process) and further benefits, such as forced decarburization or chemical heating, can be obtained. Tenova's VD can be designed as a twin unit, in order to maximize productivity without sacrificing process quality, using a single vacuum pump system.

The VOD unit is mainly used for the production of stainless steel, it provides the most suitable condition for extensive decarburization and achievement of high-purity and cleanness. The unit is basically a tank degasser equipped with an oxygen lance, but specifically configured to withstand the heat load from an intense CO emission

It is normally used for deep decarburization of high alloy steel grades, usually to remove carbon without affecting chromium content in the production of stainless steel grades. The VOD unit can be operated as the sole decarburization unit after the furnace (DUPLEX process) or as a refining stage after rough decarburization with an AOD unit (TRIPLEX process).

All the units can be equiped with either mechanical pumps or steam ejectors.

  • Efficiency

    Efficiency

    VD:

    • Hydrogen and Nitrogen removal
    • Natural and forced decarburization
    • Improved conditions for desulfurization with proper slag management
    • Improved conditions for inclusion flotation
    • Adjustment of temperature and composition 
  • Efficiency

    Efficiency

    VOD:

    • Extensive decarburization with low chromium losses
    • Use of less expensive high-carbon alloys
    • High rate of chromium recovery with proper additions
    • Chemical heating of liquid steel Hydrogen and nitrogen removal
    • Improved conditions for desulfurization with proper additions Improved conditions for inclusion flotation
  • Value for Money

    Value for Money

    • low operation & maintenance cost

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Secondary Metallurgy

The increasing demand for high-quality steel makes the secondary metallurgy to an essential step in metallurgy process. The handling of alloys, degassing and desulfurization technologies as well as high-efficient decarburization solutions are representing an indispensable part of the production of high-quality steel.