Numerical Modeling of Double High-Frequency Longitudinal Welding of Cladded Pipes

This paper deals with numerical modeling of longitudinal high-frequency (HF) induction welding of cladded pipes using double frequency approach. Solutions are proposed to reach the required temperature distribution at the welding edge for the cladding composite of S355 and Alloy 625 with single and double frequencies. An advanced consideration of magnetic and other material properties was performed to simulate the dominating physical effects of HF welding. By the use of FEM analysis, the theoretical capability of an inductive longitudinal welding process for cladded pipes has been demonstrated. Despite some simplifications, the dominating effects of the longitudinal welding were considered by the presented model. In the context of the research, a correlation for welding speed, welding frequency and temperature distribution with industrial relevance was found for the cladded pipe welding. Industrial scale process windows for both, single frequency and simultaneous double frequency is presented in this work.