Preheating Rod Assemblies for Welding

Preheating Rod Assemblies for Welding

Objective: To preheat steel rod assemblies for welding.

Background: This is an automotive industry application. The client had been using torches for preheating. However, due to process improvements thanks to new automation in their facility, torch heating became too slow. This resulted in a backlog that kept them from maximizing their throughput.

Frequency: 109 kHz

Equipment:

• Ambrell EKOHEAT® 10 kW, 50-150 kHz induction heating system with a workhead;
• Coil specifically designed for this application.

Material: Multiple magnetic steel assemblies

Temperature: 400 ºF (204 ºC)

Process:

Temperature indicating paint was applied to the part, which dissolves when the part reaches the target temperature. It took 45 to 75 seconds to heat each part to temperature, depending on part size. The height of the coil relative to the joint area is a critical consideration for this application. The distance impacts how uniformly both sides of the joint heat.

Benefits:

• Speed: Induction offers more precise heating than a torch;
• Precision: Induction offers more precise heating than a torch;
• Repeatability: With induction, the client can expect to see the same result every time a part is heated;
• Throughput: The reduced heating time enables the client to enjoy improved throughput and fully realize the efficiency gains from their investment in automation.