Theoretical and experimental analysis of electric contact surface hardening of ductile iron

Electric contact surface hardening was based on the application of contact resistance heating between the electrode and work piece, which makes use of the rapid and cooling cycles produced on metals surface without affecting the bulk of the work piece. Surface performance can be enhanced through the phase transformations that take place during the mentioned thermal cycles. In this work, the temperature field of strengthened layer on electric contact strengthening was simulated using ANSYS software; the depth and width of strengthened layer were calculated. Moreover, the effect of main processing parameters on strengthened layer was simulated. Finally, some experiments have been carried out to harden the surface of ductile iron by self-developed electric contact surface strengthening device to verify the simulated results. It is found that the error was controlled in 15% reposefully, which represents the simulated result and experimental results to a certain degree are in good agreement.