Abstract
In this paper progressive induction hardening is treated mainly on a theoretical basis. In contrast to stationary induction hardening, the progressive treatment makes it necessary to include a heat flow in the axial direction of the work piece; a single coil also leads to a magnetic field which changes in the axial direction. A model for heat generation (caused by the magnetic field) is derived based on the magnetic vector potential. The heat conduction equation, in two dimensions, is solved assuming steady–state conditions. The coordinate system is transformed to take the movement of the workpiece into consideration. After adopting steady–state conditions there will be no explicit time dependency in the heat conduction equation. Phase transformations are therefore calculated by following a node when it travels under the inductor and quenching ring. The actual speed gives temperature as a function of time. Stresses are evaluated in a similar way; it is assumed that a state of generalized plane strain exists, a one–dimensional model can then be used and a strip travelling under the inductor and quenching ring is studied. Some. theoretical results and comparisons with measurements are presented.
MST/20
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