induction annealing of stainless steel tubes ends

The annealing process changes the properties of metals and alloys by heating them to a temperature range that is high enough to alter the material properties, but low enough to avoid melting the metal. This is achieved using alternating currents of high frequency and magnetic fields.


A customer from the Automotive and Transportation industry wants to replace their annealing technology with induction heating to improve the quality and reliability of the process. The heated parts are 0.25” (0.635cm) OD x 12” (30.48cm) stainless steel corrugated tubes.
We should anneal the ends of the tube with a heated length is 0.40” (1.02cm). Cycle time must be from 0-3.7 seconds and the temperature must be set up to 1800-1900F (982 – 1037C) for one part. The main goals of this test are focusing the heat into an area and achieving superior quality, repeatability, and temperature uniformity.

Industry: Automotive and Transportation

Equipment: UltraHeat S – 2kW Induction heating system and water-cooled heat station HS-4W.


With induction heating, the samples were annealed for under 1 second each and the temperature was 1900F (1037C). Four turn coil with a tighter OD is preferred for this application.


The annealing with induction heating will help a customer for increasing the cycle time and energy efficiency of the whole process.

Read more about other annealing applications.

To request more information about this Application note, please contact us.

Reference Info: Application Note 3463-6966

Subscribe to our YouTube Channel