TPT March 2022

AR T I C L E

Thermatool Corp

Forming stability The optimum forming method is parallel vee edges, edge geometry, and burr free edge condition of roll formed material presented for closure in the HF induction forge welding process.

Thermatool HF Welders control output frequency according to a setpoint, providing the only accurate frequency control available. Precision is another matter, with high accuracy and low precision – process control is only somewhat reliable. To achieve high statistical quality levels, the HF Weld process should deliver both high accuracy and high precision. Thermatool HAZControl TM Technology HF Induction welders deliver this capability – providing business stakeholders and operators with a competitive solution in the tube and pipe market. There is no “best” frequency and power combination since it is product, and even mill, specific. These are two controllable parameters that can be optimised to match the load and heating requirements of the strip being welded at a specified speed. The only way to ensure optimisation of these two parameters is to be able to control them each independently. Understanding HF weld heat input The best HF Welding power supplies are not all about transistors of one style or another. Take the time to understand if the HF weld heat input is under control. Know what matters when selecting the right tool for the job. References [1] Aspects of Precise Heat Input Control for High Frequency Welding, Thermatool Corp. • US Patent No: 7,683,288 • US Patent No: 9,924,567 • US Patent No: 10,405,378 • And other US and International patents pending

Shandong Province Sifang Technical Development Group

Strip edge presentation stability and repeatability is vital to achieving a high-quality weld

Selecting the right tool for the job Start with product performance requirements and the materials to be welded. When product quality is of paramount importance and customers are specifying the latest high strength, micro-alloyed materials – welding speed may not be the first priority. With continually advancing steel chemistries and the development of new alloys, process windows for high quality welds can become quite small. It is important to remember that any changes to the chemistry will require changes to your heat input. Cost of scrap and the high yields necessary to remain competitive become imperatives in this circumstance.

The influence of power supply accuracy and precision in relation to weld heat input

In the HF welding context, accuracy means the ability to reproduce or return to a given power and frequency set-point. An accurate output power (kW) control is required to duplicate even the most basic HF Welding processes.

Thermatool Corp – USA info@thermatool.com www.thermatool.com

The diagram shows the desirability of operating an HF welder power supply with high levels of accuracy and precision related directly to power (kW) and frequency (kHz)

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MARCH 2022