クロムおよびニッケルをイオン注入した純鉄の注入原子の深さ分布および電気化学的性質

抄録

The concentration profiles of chromium and nickel implanted in pure iron were measured with a secondary ion mass analyzer. The electrochemical properties of implanted iron were investigated by means of a cyclic voltammetry in 0.5M acetate buffer solution (pH5.0±0.1). Chromium, nickel and argon ion implantations have been carried out with doses of 1×10¹⁶1×10¹⁷ ions/cm² at an energy of 150 keV. The target temperature during ion implantation rised to 180°C from room temperature by the heating effect of ion beam itself. The profile of Cr implanted in pure iron has two peaks; the first peak near the surface and the second peak near the depth predicted by the range theory. However, the first peak was not found in the specimen 1 st-implanted with Ni. The electrochemical properties of Cr implanted iron approach to that of Fe-18% Cr bulk alloy (SUS 430), as the dose increases. The polarization curve of Cr implanted iron with 1×10¹⁷ ions/cm² is almost the same as that of SUS 430. The polarization curve of Ni and Cr implanted iron is similar to that of Fe- 18% Cr- 8% Ni bulk alloy (SUS 304) after annealing at 300°C for 20 min.. These results show that Cr and Ni implanted surface layer is useful for the improvement of corrosion resistance of iron.