Numerical investigation of a double frequency approach for longitudinal HF welding of cladded pipes

This article contains findings of simulation research on longitudinal induction welding of cladded pipes with use of simultaneous double frequency. 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 simultaneous double frequency. An advanced consideration of magnetic and other material properties was performed to simulate the dominating physical effects of high frequency (HF) welding. The background of use and advantages of simultaneous double frequency are presented. In the context of the research, a correlation for welding speed, frequency and temperature distribution with industrial relevance was found for the cladded pipe welding

Design of an one-sided transverse flux induction coil by using a numerical optimization algorithm

The transverse flux heating (TFH) concept offers very high electrical efficiency in combination with unique technological flexibility. Numerous advantages make this method beyond competition to be applied in e.g. continuous strip production and processing lines. However, all potential advantages of TFH can be realized in practice only by optimal design of the inductor shape and optimal control of the heaters, using numerical modelling and optimization techniques. The paper describes a successive approach to optimal design of a single layer induction coil, which will be used for onesided TFH of moving thin steel strip with constant width. The peculiarity of the design refers to the very slow movement speed of the strip and the target temperature, which is set below Curie

Hierarchical optimization approaches in designing surface hardening induction systems

Induction surface hardening is a quite traditional and well-known process in which a metal part is induction-heated and then quenched. The quenched metal undergoes a martensitic transformation, increasing the hardness and stiffness of the part. The design of a surface hardening system is a challenging task. This paper describes an approach to divide a full problem into simpler ones and to optimize the electrical regime. We compare the effectiveness of using a single-objective rather than a multi-objective optimization approach