Preheating Parts for Welding

Preheating Parts for Welding

Objective: To preheat castings and rods before welding; they were looking for faster, more repeatable heating than torches offered.

Equipment: Ambrell EKOHEATⓇ 20 kW, 15-40 kHz induction heating power supply with a workhead and coil specifically designed for this application.

Material: Magnetic steel castings and rods

Temperature: 450 °F (232 °C)

Testing:  

• A custom-designed single position multiple-turn helical coil was built to generate the required heating for the application. Both parts were heated using the same coil. Initial tests confirmed that both parts absorbed heat very well.

Testing proved the viability of the application. The client targeted a heating time of 3 minutes. Using a torch, heating took 20 minutes.

Benefits:

• Speed: Induction dramatically reduced the heating time they saw with torch heating as it dropped from 20 minutes to 3 minutes.
• Repeatability: The client can expect the same result in the same amount of time every single time. A torch is prone to more variability.  
• Employee Safety/Work Environment: With induction there is no open flame and with induction’s instant on/off capabilities, it introduces less heat into the work environment.