Vacuum Cap

Vacuum Degassing and Controlled Atmosphere Melting VAR
Consarc has developed a new range of induction melting furnaces. The purpose for creating this line of furnaces
is for the of processing ferrous and non-ferrous metals
under vacuum in the liquid state.

Consarc has more than 40 years experience with
designing Vacuum Induction Melting furnaces (VIM)
and Inductotherm is the world leader in induction
melting furnace and power supply technology. With
this new product, the technology and experience of
these two giants in their field is combined to provide
a flexible melting furnace system for melting metals
in air, vacuum or controlled atmosphere — Vacuum
Cap (VCAP).

The VCAP furnace is designed for Induction Melting
a solid charge in an air atmosphere (or vacuum), with
final degassing stage under vacuum. The final pouring
of the metal is performed in air or under protective atmosphere of inert gas. Configuration is based
on the Inductotherm range of steel shell induction furnaces which are fully adapted by Consarc for
vacuum treatment of liquid metal.

The furnace shell is fully sealed for vacuum operation and a sealing flange/apron is provided on top
of the unit. A water cooled vacuum lid can be placed on top of the furnace, either by factory crane or dedicated lift/swing pivot arm (option), following the air melt operation (or vacuum/inert gas if required).
The system is making a vacuum chamber connected to a multi stage mechanical vacuum pumping system. This system can evacuate the atmosphere above the molten bath.

The induction melting coil is powered from an Inductotherm
VIP Power supply with the power and frequency matched
for fast melt rates (high productivity) and optimum stirring (metallurgical quality) in the liquid state. The stirring
frequency ensures that the alloy is fully homogenized
and that fresh liquid metal is cycled to the surface of the
bath to aid the degassing procedure.

Once the atmosphere is evacuated, the degassing
procedure and intensified C-O reaction allows removal
of undesirable gases, Hydrogen, Nitrogen, and Oxygen
to much lower levels than would be possible in air.

At the end of the degassing sequence, the vacuum lid can be removed and a protection ring is
placed around the sealing flange. The furnace is then ready for tilt pouring into the customer’s
transfer ladle or molds. The pouring process is usually carried out in air (option for protective
atmosphere).

Vacuum Cap Furnace Specifications
Applications and Materials
The VCAP furnaces are available to suit a wide variety of application in sizes ranging from 80 kg
to 20 tonnes. Typical applications might include:

• Low and high carbon steels
• Stainless steels
• Cobalt based alloys

• Tool and die steels
• Nickel based alloys
• Non ferrous alloys

Metallurgical Considerations
Some typical processes that can be performed in the VCAP range include:

• Air melting from solid charge (option for vacuum melting)
• Controlled atmosphere melting from solid charge
• Alloy homogenization and chemistry adjustment
• Vacuum degassing (hydrogen and nitrogen removal)
• Reduction of low vapor pressure tramp elements (e.g. Pb, Cd, Bi, Zn)
• Deoxidation using combination of vacuum and C-O reaction
• Decarburization - Intensified C-O reaction at low pressure enabling
excellent decarburization for extra low carbon levels.
• Desulphurization
• Argon purging of metal with pourous plug

Some of the more important customer product advantages from VCAP operation are:

• Generally significant improvement of mechanical properties, such as yield strength,
ductility, impact strength, fatigue and stress rupture elevated temperature properties.
• Improvement of technological characteristics, such as hot workability, weldability and
machinability.
• Better microcleanliness due to strong carbon deoxidation and smaller residual inclusions.
• Significantly reduce scatter in product properties and characteristics, less rejections.

Flexible Design Approach
The VCAP furnace range provides a fully flexible, cost effective approach to furnace build with a range
of options to best suit individual customer budget and technical requirements.

The standard units are complete with:

• Induction furnace & vacuum shell
• Hydraulic tilt system
• Inductotherm VIP power supply

• Water cooled vacuum lid
• Viewing ports
• Immersion thermocouple

• Vacuum pumping system
• Water cooling manifolds
• Control systems

Optional accessories can be fitted as required including:

• Porous plug inert gas (argon) purging
• Optical pyrometer
• Closed loop water cooling
• Hydraulic lining pushout
• High voltage supply transformer

• Automated vacuum lid handling
• Vacuum isolated sampling and
fines charging
• Scrap and raw material charging
• SCADA supervisory control systems