Annealing a steel shaft for stress relief

Objective

Heating a steel rod to 1200ºF (649ºC) for an annealing, stress relief application 

End Product

Steel shaft

Equipment

• Ambrell 45 kW induction heating system, equipped with a remote workhead containing eight 1.0 µF capacitors for a total of 8.0 µF

• An induction heating coil designed and developed specifically for this application. 

Materials

• 1.062” (26.97mm) dia type T-410 stainless steel bar 6’ (1.82m) long

• 1.25” (31.75mm) dia T-416 stainless steel bar 6’ (1.82m) long 

Temperature

1200ºF (649ºC)

Frequency

126 kHz

Testing

A two position 8 turn helical parallel coil is used to heat the stainless steel rod for 30 seconds to reach the requested 1200ºF (649ºC). 

Benefits

Induction heating benefits:

• Process currently done in batch furnaces, induction heating allows process to be done in-line saving time and energy.

• No rotation of part needed

• Flameless process

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