Patent ID: 9121081
Filing Date: 2015-09-01
Classification: C21D,H05B,Y02P

Abstract:
1. An apparatus for induction heat treatment of a workpiece, the apparatus comprising: an induction coil at least partially surrounding the workpiece; a generally C-core inductor comprising a first core segment and a second core segment, the workpiece disposed in a gap between the first core segment and the second core segment to form a magnetic circuit with the generally C-core inductor; a solenoidal coil wound around a section of the first core segment; a first power supply providing a first ac current to the induction coil to induce a first ac magnetic field around the induction coil, the first ac magnetic field coupling with the workpiece to inductively heat the workpiece; and a second power supply providing a second ac current to the solenoidal coil to induce a second ac magnetic field in the magnetic circuit to heat the workpiece by the Joule effect, the frequency of the second ac current lower than the frequency of the first ac current.