Reference
Resistivity vs Temperature
How electrical resistivity changes with temperature for common induction heating materials. The Curie knee in ferromagnetic materials is the most important feature to understand.
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ρ(T) Curves
°C
Curie Knee: At the Curie point, ferromagnetic materials lose their magnetic permeability (μr → 1).
The sharp rise in resistivity combined with the loss of magnetic coupling creates the “Curie knee” —
heating slows dramatically at this temperature because induction power delivery depends on both resistivity and permeability.
Carbon steel transitions at ~770°C; nickel at ~358°C; ferritic stainless at ~750°C.
Skin Depth at Temperature
Hz
| Material | ρ (μΩ·cm) | δ (mm) |
|---|
Cursor Reading
20 °C
Below Curie — ferromagnetic regime