A three sweep potentiokinetic technique was employed to study the electrochemical corrosion behaviour of Fe-50 at % Ni in .1N H2SO4 solution. The as received foil did not show any passivation but it was observed in case of Fe−Ni samples implanted with N2+ ions at an energy of 100keV. Also it was seen that the primary passivation potential Epp and the critical current density in the corrosion experiment decrease as the implanted nitrogen ion dose increases from 5*1015 to 1*1017 ions/cm2. The identification of products formed during corrosion experiment has been attempted with the help of conversion electron Mossbauer spectroscopy (CEMS), X-ray diffraction (XRD) and X-ray photoemission spectroscopic (XPS) techniques, and the possible mechanism of reactions is discussed with reference to their results.