Enhanced corrosion resistance and electrical conductivity of stainless steel bipolar plates by molybdenum ion implantation

To enhance the corrosion resistance and electrical conductivity, the surface of 316L stainless steel was modified by the ion implantation of Mo. By investigating various accelerating voltages and implantation doses, it was found that the corrosion resistance of stainless steel was enhanced by 50%–80% and the surface conductivity by 15%–28% at most. The minimum stabilized current density is 0.72 μA/cm². This is due to the formation of a Cr and Mo riched modified layer on the surface of the stainless steel. Mo oxides synergize with Cr oxides in the form of a solid solution to enhance the corrosion resistance of passivation films on the stainless steel surface. The optimum parameters were Cr in the proportion of 6%–8% and Mo in the proportion of 4%–5%.