FINITE-ELEMENT SIMULATION OF MOVING INDUCTION HEAT-TREATMENT

An efficient finite-element procedure with a remesh scheme has been de veloped for the analysis of the moving induction heat treatment proces s, wherein relative motion occurs between the coil and the workpiece. In this procedure, the magnetic field is first simulated by using an u pdated mesh that tracks the moving coil position; the moving heat sour ce within the workpiece material is derived from the magnetic field. T he heat equation is then solved to obtain the temperature field create d by the heat source, The procedure has been applied to calculate the temperature distributions in 1080 carbon steel cylinders during induct ion heating. The calculations have been validated by comparison with a nalytical solutions for the temperature distribution obtained using Gr een's function methods, Finally, the temperature, residual stress, and microstructure distributions in quenched 1080 steel cylinders have be en obtained using the finite-element procedure. Quenching of the heate d cylinders, by both a moving cooling ring and a stationary liquid bat h, has been analyzed, The finite-element procedure presented incorpora tes temperature-dependent material properties, phase transformations o ccurring in the 1080 steel, the change in magnetic permeability of the 1080 steel at the Curie temperature, and an elastoplastic stress mode l based on a mixed hardening rule. The simulation results demonstrate that the finite-element procedure could be applied to a variety of mov ing induction heat treatment problems to determine the residual stress and microstructure distributions in the heat-treated component. It al so could be used in the design of process parameters and coils.