The finite element analysis of applying the controlling pouer on the surface transformation hardening in the vicinity of discontinuity in the workpiece depth

In the present research, the finite element analysis of the surface transformation hardening in the vicinity of workpiece discontinuity was performed both thermally and metallurgically using ABAQUS finite element software. In order to predict the volume fraction of the obtained phases and the hardness profile during continuous cooling stage, the appropriate user-defined subroutine based on the Kirkaldy kinetic model was employed in the data flow of the software. Besides the effects of different controlling strategies and the application of a quenching medium at the discontinuity surface was investigated. Based on the obtained results, these strategies which are based on controlling the input power and travelling speed of the heat source as a function of the maximum temperature at the surface, allows for gaining a more uniform thermal history at the surface. However, as these strategies could not control the cooling rate in the vicinity of discontinuities, applying a quenching medium with an optimum cooling power is essential in order to achieve a uniform hardened layer at the workpiece depth.