Systems and methods of hot forming a metal blank include receiving the metal blank at a heater and positioning the blank adjacent a magnetic rotor of the heater. The systems and methods also include heating the metal blank through the magnetic rotor by rotating the magnetic rotor. Rotating the magnetic rotor induces a magnetic field into the metal blank such that the metal blank is heated.

Systems and methods of pre-ageing of a metal strip during metal processing include passing the metal strip adjacent a magnetic rotor of a reheater. The systems and methods also include heating the metal strip through the magnetic rotor by rotating the magnetic rotor. Rotating the magnetic rotor induces a magnetic field into the metal strip such that the metal strip is heated.

A compact heat treatment line can include a short heating zone capable of rapidly bringing a metal strip to a suitable solutionizing temperature through the use of magnetic rotors, such as permanent magnet magnetic rotors. A fast and efficient soaking zone can be achieved as well, such as through the use of magnetic rotors to levitate the metal strip within a gas-filled chamber. Magnetic rotors can further levitate the metal strip through a quenching zone, and can optionally reheat the metal strip prior to final coiling. Magnetic rotors used to heat and/or levitate the metal strip can also provide tension control, can facilitate initial threading of the metal strip, and can cure coatings and/or promote uniformity of coatings/lubricants applied to the metal strip without overheating. Such a heat treatment line can provide continuous annealing and solution heat treating in a much more compacted space than traditional processing lines.

A non-contact heating apparatus uses a series of rotating magnets to heat, levitate, and/or move metal articles therethrough. A first series of rotating magnets heats the metal article to a desired temperature. A second series of rotating magnets levitates the metal article within the heating apparatus and maintains desired tension in the metal article, including urging the metal article through the heating apparatus. The heating apparatus can extend sufficiently far to soak the metal article at the desired temperature for a desired duration. The rotating magnets can be positioned outside of an electrically non-conductive, heat resistant chamber filled with an inert or mildly reactive gas, through which the metal article passes in the heating apparatus.

A variable width transverse flux electric inductor has a fixed powered coil section and associated box-like moveable passive coil sections that electromagnetically couple with magnetic flux generated by current flowing through the fixed powered section. The passive coil sections can be transversely moved across the workpiece to accommodate induction heating of workpieces having different widths or track movement of the workpiece. Alternatively the fixed powered coil section and associated moveable coil sections may be connected to each other through flexible connections, sliding contacts or other means, such as clamps, so that an electrical connection can be maintained between both in any relative position.

A solenoidal induction coil with dynamically variable coil geometry is provided for inductively welding or heating continuous or discontinuous workpieces passing through the solenoidal induction coil in a process line. The coil geometry can change, for example, as the outer dimension of the workpiece passing through the solenoidal induction coil changes or as non-continuous workpieces pass through the solenoidal induction coil in an induction heating or welding process line.

A control unit of an induction heating unit controls AC power output to a heating coil of a transverse type induction heating unit that allows an alternating magnetic field to intersect a sheet surface of a conductive sheet that is being conveyed to inductively heat the conductive sheet. The control unit includes: a magnetic energy recovery switch that outputs AC power to the heating coil; a frequency setting unit that sets an output frequency in response to at least one of the relative permeability, resistivity, and sheet thickness of the conductive sheet; and a gate control unit that controls a switching operation of the magnetic energy recovery switch on the basis of the output frequency set by the frequency setting unit.

An induction heating apparatus for heating a traveling metal plate includes an induction coil for surrounding the metal plate. The induction coil includes an upper portion for being located above the metal plate and a lower portion for being located below the metal plate. The upper and lower portions of the induction coil are spaced from each other in a longitudinal direction of the metal plate at least at one position in a transverse direction of the metal plate. The distance in the longitudinal direction of the metal plate between the upper portion and the lower portion of the induction coil varies across a transverse direction of the metal plate.

High frequency electrical heating system is provided for heating electrically conductive parts as they are advanced, either for annealing or welding processes, and in which the electrical heating current is supplied by a solid state DC to AC inverter through a load matching and frequency control circuit that maintains the desired load current and frequency with changes in the load impedance caused by the electrically conductive parts as they are advanced. Load matching is achieved with high frequency variable reactors having a geometrically-shaped moveable insert core section and a stationary split-bus section with a complementary geometrically-shaped split bus section and a split electric terminal bus section where the insert core section can be moved relative to the stationary split-bus section to vary the inductance of the reactor pair.

The transverse flux induction heating device allows an alternating magnetic field to intersect the sheet face of a conductive sheet which is conveyed in one direction, thereby inductively heating the conductive sheet. The transverse flux induction heating device includes a heating coil disposed such that a coil face faces the sheet face of the conductive sheet; a core around which the heating coil is coiled; and a shielding plate formed of a conductor and disposed between the core and a side end portion in a direction perpendicular to the conveyance direction of the conductive sheet, wherein the shielding plate has a protruded portion, and the side surface of the protruded portion represents a closed loop when viewed from a direction perpendicular to the coil face.