Induction Annealing an oval cut out on a stainless steel tube

Objective To anneal a area around an oval cutout on a stainless steel tube prior to extrusion
Material:.75" (19mm), 1.5" (38.1mm) and 4" (101.6mm) diameter steel tubes
Temperature: 1900 °F ( 1038 °C)
Frequency: 50KHz
Equipment:
• UM-60AB-HF induction heating system, equipped with a remote workhead containing one 1 .0uF capacitor.
• An induction heating coil designed and developed specifically for this application.
Process:A single turn helical coil is used on the 4" (101.6mm) diameter tubes and a two turn helical coil is used on the smaller diameters. The coil is placed over the oval cutout and power is supplied for 15 seconds to anneal a .25 (6.35mm) diameter around the cutout.
Results/Benefits:
Induction heating provides:
• Precise and controllable placement of heat to anneal only the required area
• Faster process than flame
• Repeatable results
• Hands-free heating that involves no operator skill for manufacturing

4 inch (101.6mm) diameter tube heated

smaller diameter tube heated