Pre-Heating for Welding
Research Objective
To uniformly heat jet engine turbine fan blades to 1800°F within five minutes for a welding application
Parts & Materials Description
Jet engine turbine fan blades with 2” length tip
Temperature Required
1800°F
Induction Heating Equipment
3 kW solid state power supply, remote heat station and a specially-designed induction coil.
Operating Frequency
216 kHz
Heating Procedure
A four-turn helical coil with a kidney shape was used to provide uniform heat for this application. Initial tests were conducted to establish a heating profile and time-to-temperature. The turbine blade was placed inside the coil and power was applied until the top 0.25” of the blade reached 1800°F. An optical pyrometer was used to measure the temperature of the part. The desired temperature was reached in 5 minutes.
Conclusion
Consistent and uniform results were obtained with the 3 kW power supply and coil; ±3°F temperature uniformity was achieved from the leading edge of the blade to the trailing edge. A 5 kW power supply could be used to further reduce the heating cycle.
