EBNER GREENCAL Heat treatment furnace facilities

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GREENCAL Heat treatment furnace facilities for the steel industry

Heat treatment of Ni-coated battery steels

Nickel-coated steel strip, manufactured from a low-carbon material and with a small proportion of alloying elements, is generally used to create battery steels. Depending on the thickness of the strip, the desired mechanical properties and the intended application, a number of different processing methods may be employed. The special heat treatment process used in the manufacture of such strip can be carried out either in a proven HICON/H2 bell annealer facility, with the strip in coil form, or in a continuous process in a continuous heat treatment facility.

For the continuous process, EBNER has developed an innovative new design: the horizontal GREENCAL continuous annealing line. This design allows every heat treatment technology used in the manufacture of Ni-coated steel strip to be incorporated into a single processing line.

The combination of extremely pure process atmosphere and high convection leads to an extremely precise temperature distribution across the width of the strip, even as it also provides a high throughput and reproducible material properties.

Typical strip dimensions and processing speeds

  • Max. strip width: 800 mm / 1000 mm / 1220 mm
  • Strip thickness : 0.1 to 1.0 mm
  • Line speeds: up to 100 m/min

Typical applications for Ni-coated strip

  • Cylindrical battery cell casings in electric vehicles
  • Standard household batteries
  • Button cell batteries for use in corrosive conditions

Steel strip for battery cell casings is distinguished by

  • Isotropic deep drawing characteristics due to special heat treatment process
  • High mechanical stability
  • High corrosion resistance
  • Long service life

Additional applications of horizontal GREENCAL continuous annealing lines

  • Deep-drawing steels
  • Multi-phase steels
  • Non-grain-oriented (NGO) electrical steel strip
  • Martensitic carbon steel strip
  • Martensitic stainless steels
  • Copper and copper alloys
  • Special alloy

Advantages of the EBNER design

Flexible facility design

  • A variety of heat treatment technologies can be incorporated into a single line
  • Different types of heating systems can be combined in a single line
  • Modular facility layout allows performance to increased at a later date
  • Flexible heating and cooling rates can be adapted to technological requirements
  • Processing temperatures up to 1,100 °C

Heating methods

  • Electric heating system with HICON high convection circulation system
  • Electric heating system with radiant tubes
  • Induction heating system
  • Gas-fired heating system with high-efficiency,
  • low-emission radiant tubes

Flexible temperature track

  • Extremely precise temperature control
  • Variable heating and cooling rates
  • Flexible soaking times

Gas-tight furnace design with variable atmosphere selection

  • Depending on application, process atmospheres with up to 100 % hydrogen can be selected
  • Specially-designed seals at inlet and outlet, as well as at roller leadthroughs
  • Exact atmosphere flow and furnace pressure regulation
  • Proven safety system design, even using 100 % hydrogen as process atmosphere

Lowest energy and utility consumption

  • Extremely efficient heating system design
  • Insulated with special fiber modules
  • Up to 80 % of process atmosphere can be recycled
  • Thermal energy can be directly recovered from the process

Damage-free strip transport

  • Driven sealing rolls in the furnace inlet and outlet seals
  • Special materials used for furnace rolls
  • Individual roller drives with precisely-operating servo drive units
  • Prevention of deposits on rolls / long hearth roller service life
  • Extremely high degree of availability

Facility design that is easy to operate and maintain

  • Easy access to interior of furnace
  • Easy roller removal (no overhead crane required)
  • Strip break detection, including protective devices for components in furnace interior
  • New strip can be easily strung
  • Rapid heating and cooling of the furnace facility when switching between processes