Induction Hardening

Induction hardening offers excellent hardness distribution with minimal deformations

Induction hardening offers considerable advantages over conventional methods. However, induction hardening also places the high demands on the generators and the inductor used. Ideal hardening results can only be achieved by perfectly matching a precisely controlled energy source with optimum inductor design.

Heating directly in the workpiece with induction hardening

Induction hardening is a heating method in which the heat is generated directly in the workpiece. The principal advantage is that the heat is not applied to the part indirectly by heating its surface. In conventional heating methods, such as with a flame or an oven or by convection, heat is applied to the part by heating up its surface. These methods take considerably longer and require significantly more energy to produce the desired hardening result. Induction hardening, by contrast, offers extremely short heating times, making it a very attractive method especially in the industrial sector. Moreover, induction heating can be controlled very precisely via the power, frequency, and the inductor geometry. This minimizes deformations in the workpiece and ensures that the process is highly efficient.

How induction hardening works

A coil is used to generate an alternating electromagnetic field that induces alternating currents in the workpiece. The electrical resistance in the workpiece causes it to heat up. The heat is thus generated in the workpiece exactly in the desired location.
The induction heating method is used primarily for surface hardening. The hardening depth in the workpiece is precisely controlled via the electrical power output and frequency of the inductor/coil current in order to achieve an optimum hardening result. The generator is a particularly important component in this process. The energy source must be adapted to the requirements of each application so that the frequency is perfectly matched to the hardness distribution required.

Different frequency ranges for induction hardening

  • Low frequency: 1–7 kHz
  • Medium frequency: 8-40 kHz
  • High frequency: 60-500 kHz

eldec offers energy sources with the latest converter technology for all three frequency ranges .

Induction hardening with Simultaneous Dual Frequency

With Simultaneous Dual Frequency, also known as SDF, eldec offers a further method that is used especially for workpieces with complex shapes. A medium frequency is overlaid with a high frequency so that both act upon the workpiece simultaneously.

Induction Hardening

What are the advantages of induction hardening?

  • Outstanding control of the hardening process
  • Highly versatile in application
  • Minimal space requirements
  • Minimal heating times
  • Accurate hardening results on contours
  • Minimized deformation of the workpieces
  • Ideal integration into manufacturing systems
  • High process stability
  • Excellent energy efficiency
  • Safe heating method




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