X-ray diffraction (XRD) measurement and transmission electron microscopy (TEM) were used for characterizing components of corrosion products, which are formed by immersing a pure iron (Fe) and an Fe-2mass% Mn alloy (Fe-Mn) in a Na_2SO_4 solution for 24, 96, 168, 336h. The amounts of iron and manganese in the solution were analyzed by means of inductively coupled plasma (ICP) atomic emission spectrometry, and pH and ORP measurements of the solution were also carried out. XRD patterns show that the corrosion products consist mainly of γ-FeOOH and magnetite, but the amount of magnetite in corr...