The polarizing characteristics of synthesized nitrides, Fe_3N, Fe_4N, Mn_3N_2 Mo_2N, MoN, Cr_2N CrN, VN, Si_3N_4 AlN, TiN, ZrN and NbN, were studied by means of potentiostat in order to determine the condition for the electrolytic extractions of nitrides from iron and steel. From the results of polarization curves and natural electrode potentials of iron and nitrides, some useful informations were obtained as to the electrolyte and the electrolytic potential for the electrolytic extractions of nitrides contained in iron and steel ; that is, if a suitable electrolytic potential is applied, both acidic and neutral solutions can be used as an electrolyte for the extractions except nitrides of Al, Fe and Mn. For the Fe-nitride, only neutral electrolyte is useful, while for the nitrides of Al and Mn, there seems to be no favorable electrolyte
