Soft Magnetic Composite Impeder Geometry Optimization

Induction tube welding is used for the continuous production of metallic tubes. These systems often utilize an internal magnetic flux controller (impeder) to improve process efficiency. Significant energy savings and increased productivity have been demonstrated both theoretically and practically when switching from the traditional ferrite impeder core, to one made of a soft magnetic composite (SMC) with high saturation flux density. In order to use SMCs in these systems it is important to balance the greater heat generated in these materials at higher fields with the cooling water available.

In a previous study, a test stand was devised for physical simulation of SMC impeder performance for use in induction tube welding systems. Design envelopes were created outlining the conditions in which impeder cores made of SMCs with an identical geometry to the traditional ferrite could survive in induction tube welding systems. The goal of this study is to build upon those initial findings through extended physical simulation using an improved test stand, improve the accuracy of the computer models, as well as determine the optimal geometry for SMC impeders to expand the experimentally developed operational envelopes to the theoretical limits of the material. Optimizing the geometry to balance losses and cooling of SMC impeders will expand these operational ranges to cover a wider range of process frequencies and magnetic core loading in induction tube welding systems and provide a better idea of the applications in which SMC impeders may provide substantive benefits compared to traditional impeders.