Seconedry Metallurgy

 

 

 

 

 

 

 

 

   

 

LF:
Installation of a ladle furnace between the melting and casting areas is vital to assure quality and/or productivity improvements in steelmaking.
Ladle furnace arrangements include single stations (with fixed/swiveling gantries or with ladle cars/turrets) and also twin stations (two roofs) with one swiveling electrode gantry.

Features:
Most advanced and outstanding design features
Water-cooled roof without refractory lining in center area
Automatic lance manipulator for temperature measuring and sampling
Automatic lance manipulator for stirring and/or powder injection
Wire feeding for deoxidization and microalloying
Automatic coupling system for stirring gas

Inert gas stirring system ( porous plugs and/or purging lance ).


AOD:
Metal refining konvertor is used for making stainless steel of various grades. Molten Steel produced from Induction Furnace or Electric Arc Furnace is poured into ladle & is subsequently poured into the converter with the help of E.O.T. Crane. Before pouring the molten metal, some important parameters like its temperature & chemical composition are analyzed. Based on this analysis, molten steel is refined by addition of required alloys & fluxes. Inert gases are also blown into the converter simultaneously.
APPLICATION
• Decarburization
• To make Stainless Steel grades, Alloy Steel Economically by using High Carbon Fe Alloy and Mild Steel Scrap/Sponge Iron.
• This process is Air – Oxygen – Inert gas Decarburization (AOD) process, for aking Stainless Steel out of mild steel, Mild Steel out of high Cast Iron Melt, and alloy steel economically.
• PLC based Gas Mixing Station of MRK gives flow measurements compensated for pressure and temperature variation. This avoids, “over oxidation” of liquid metal.
• Imported Transducer used for accurate flow and pressure measurement in Gas Mixing Station of MRK enables high turn down ratio which results in low process gas and refractory consumption and high recovery of alloying elements.
• Use of dry air (-80o C dew point) as process gas reducing the cost of production.


VD ( Vacume Degassing ) :
During the VD process, the metallurgical work takes place in the steel ladle. The liquid steel ladle is placed in a vacuum tank, which is connected to a vacuum pump system. The ladle is equipped with porous plugs through which inert gas is injected into the melt in order to promote stirring. Depending on the metallurgical reactions during the process ladle freeboards of 800 - 1200 mm are required. If equipped with an additional oxygen lance further benefits such as forced decarburization or chemical heating can be obtained, as known under VD-OB.
Metallurgical and operational tasks:
Hydrogen and Nitrogen degassing
Decarburization and forced decarburization with oxygen lan
Desulfurization by slag metallurgy
Deoxidation by the addition of aluminium
Inclusion shape control
Adjustment of temperature and analysis
VOD ( Vacume Oxygen Decarburisation ) :
The VOD plant is mainly used for the production of stainless steel. The plant is basically designed as a tank degassing plant which is additionally equipped with an oxygen blowing lance and other related equipment. Due to the reduced CO partial pressure under vacuum conditions, decarburisation of high-alloyed steel grades to very low carbon contents is possible.

Metallurgical and operational tasks:
Vacuum operation possible with varying initial carbon contents
High flexibility to use lower cost high carbon alloying materials
Low chromium oxidation losses
High rate of chromium recovery by slag metallurgy
Chemical heating of liquid steel
Low final dissolved gas contents
Improved steel cleanliness with
Achievement of exact compositional values within narrow tolerances