Preheat time has been reduced from 2 h down to 10 s. Over 700,000 BTU’s worth of natural gas-fired infrared heaters have been replaced with a single Ajax Tocco 35 kW Toccotron AC induction heating power source.
Total fabrication time was reduced by over 60 %, allowing the manufacturer to produce one weldment per shift versus one weldment every 2.5 shifts.
Each of the two inductors are positioned approx. 24 inches in front of two 1000-amp sub arc weld torches. The inductors and torches move in tandem. The weldment is simultaneously heated and welded as gantry traverses the length of the fillet.
Real-time, active temperature feedback and control are provided by an Ajax Tocco-supplied, non-contact infrared sensor. The output of the induction heater is constantly varied by the PID controller to maintain a constant user-defined preheat temperature.
Ajax Tocco air-cooled induction weld preheat systems offer many advantages including:
- Controlled cooling rates
- Increased penetration
- Increased feed rates
- Improved quality
- Reduced consumables
- Improved operator comfort
- Decreased energy use
- Improved safety.
(Source: Ajax TOCCO Magnethermic Corporation)





