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 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.

Provided is a high frequency induction heating apparatus capable of quenching a workpiece having an outward flange, over the whole circumference by means of a frequency with which a penetration depth of an electromagnetic wave is larger than a sheet thickness of the workpiece The high frequency induction heating apparatus includes a high frequency induction heating coil used for heating a long hollow steel workpiece having a closed cross section and an outward flange, in 3DQ in which a bending member is manufactured from the workpiece The high frequency induction heating coil includes a magnetic material core facing each other between which both faces of the outward flange are interposed, having a distance from both faces, and an induction heating coil connected to the magnetic material core and arranged surrounding an outer circumference of a general portion where the outward flange is excluded from the workpiece.

An induction heating apparatus includes: a core that has a pair of magnetic poles and transfers magnetic flux; a coil generating magnetic flux; conductors adjacently provided on both left and right sides of the magnetic poles; and lateral magnetic members formed of a magnetic material and arranged on an outer side of end portions of the object so as to extend along the end portions. The conductors shut off the magnetic flux that flows from a center portion of the heating object, taking a detour to the end portions, permit the magnetic flux to concentrate on the center portion, and accelerate temperature rise. The lateral magnetic members introduce the magnetic flux that propagates from one surface to the other surface, detouring around the end portions to thereby mitigate the magnetic flux density in the end portions and suppress overheating.

A rail heating head includes a vented enclosure and an induction coil. The induction coil is positioned within the vented enclosure. When in use, the vented enclosure is positioned adjacent a lateral portion of a train track rail. To be positioned adjacent to the head, the web, and the foot of the train track rail, a rail-bracing wall of the vented enclosure has a convex exterior surface and a concave interior surface. The induction coil has an oblong, concave shape and is pressed against the concave interior surface. Thus, the induction coil can induce eddy current magnetic fields in the head, the web, and the foot maximizing surface area. The larger surface area results in molecules in a large area being activated and leads to more heat. An eddy current deflecting magnetic shield further directs magnetic fields towards the train track rail.

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.

A coil assembly for an induction heating device comprises: a first coil part which has, on one surface thereof, a first cooling-pipe insertion groove indented to the inside thereof; a first cooling pipe coupled to the first cooling-pipe insertion groove so that a part of the outer surface can be exposed; a second coil part which is disposed to be opposite to one surface of the first coil part provided with the first cooling-pipe insertion groove and has, on one surface opposite to the one surface of the first coil part, a second cooling-pipe insertion groove indented to the inside thereof; and a second cooling pipe coupled to the second cooling-pipe insertion groove so that a part of the outer surface can be exposed.

A rotating magnet heater for metal products, such as aluminum strip, can include permanent magnet rotors arranged above and below a moving metal strip to induce moving or time varying magnetic fields through the metal strip. The changing magnetic fields can create currents (e.g., eddy currents) within the metal strip, thus heating the metal strip. A magnetic rotor set can include a pair of matched magnetic rotors on opposite sides of a metal strip that rotate at the same speed. Each magnetic rotor of a set can be positioned equidistance from the metal strip to avoid pulling the metal strip away from the passline. A downstream magnetic rotor set can be used in close proximity to an upstream magnetic rotor set to offset tension induced by the upstream magnetic rotor set.

Systems and methods of threading a metal substrate on a rolling mill include receiving a coil of the metal substrate. The method also includes uncoiling the metal substrate from the coil while the coil and guiding the metal substrate to a work stand of the rolling mill with a threading system.

Systems and methods of non-contact tensioning of a metal strip during metal processing include passing the metal strip adjacent a magnetic rotor. The magnetic rotor is spaced apart from the metal strip by a first distance. The systems and methods also include tensioning 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 tensioned in an upstream direction or a downstream direction. In other aspects, rotating the magnetic rotor induces a magnetic field into the metal strip such that a force normal to a surface of the metal strip is applied to the metal strip.