Effect Of High Energy Denisity Pulse Current On Solidification Microstucture And Wear Resistance Of High Manganese Steel

In this study, the effect of pulse current on the solidification microstructure of ZGMn13Mo2 steel was investigated using an own-designed pulse current equipment and a high temperature crucible furnace. The melting and solidifying temperatures of the steel were measured by DSC analysis. Meanwhile, the starting and ending temperatures for pulse current treatment were confirmed based upon the results. The solidification microstructure was observed using metallographic microscope, SEM, EDS and TEM. The phase of the steel was determined by the means of X-ray diffraction analysis. The hardness and wear resistance of the steel was measured by a hardness test equipment and a ML-10 wear experimental device. The results show that the solidification microstructure of the steel can be obviously refined by the pulse current treatment. The austenitic grain size of the steel was refined down to 8μm from 300μm. The relative content of the austenite and carbide phase in the solidification microstructure of the steel was changed by the pulse current treatment. The refinement effect was relevant to the pulse current density and the pulse frequency. The solidification microstructure was refined more obviously with the pulse frequency increasing under a suitable pulse current density condition. The hardness and the wear resistance of the steel were both enhanced by using the pulse current treatment. The mechanism that the solidification microstructure can be refined by pulse current treatment is primary pulse current induced nucleation.