Improving the Energy Efficiency of the Production of Pipes Welded with High-Frequency Induction

This article presents the technical aspects that may reduce electric power consumption during the welding of pipes with the high-frequency induction (HFI) method. Experiments were carried out at Huta Labedy S.A. Steelworks, during the test production of 323.9 x 5.6 mm pipes of P235GH steel grade. Two sets of HFI heating system settings were studied: with a variable squeeze force of the heated edges and a variable position of the inductor in relation to the welding point. It was proven that the temperature at the welding point increased due to the stronger squeeze of the heated edges, which reduced the electric power consumption. Reducing the distance of the inductor relative to the welding point had the same effect. By optimizing the squeeze force and the position of the inductor, energy consumption was reduced by about 5.5%. Microstructural studies of the welds did not show any adverse effects of the optimization.