Research On Electrochemical Corrosion And High Temperature Oxidation Behavior Of ODS Steel

Aluminum and its alloy, magnesium alloy, zirconium and stainless steel are used for nuclear materials. The stainless steel is widely applied in industry for its good corrosion resistance, oxidation resistance, high strength, ductile, etc. However, the conventional stainless steel is unsuitable service environment of nuclear materials. The new nuclear structural materials will be developed.Oxide dispersion strengthened (ODS) steel fabricated by mechanical alloying is the candidate super critical water-cooled reactors (SCWR) for its excellent high temperature strength and resistance to swelling in heavy radiation. The electrochemical corrosion and high temperature oxidation behavior of ODS steel with different Cr contents were investigated in this work. The results are as follows:(1) The electric polarization curve indicated that the ODS with high Cr contents has superior corrosion resistance.18Cr-ODS steel has the best corrosion resistance. Although both 18Cr-ODS steel and 18Cr-NA steel have the same Cr contents, the corrosion resistance of 18Cr-ODS steel is superior to that of 18Cr-NA steel.(2) The surface of ODS steel with increasing Cr contents has smaller corroded grain and compacter corruption film, which increases the corrosion resistance property of ODS steel.(3) The results of high temperature oxidation experiment showed the ODS steel with high Cr contents had good oxidation resistance. The more Cr contents in ODS steel, the better oxidation resistance of ODS steel.(4) The surface appearance of the ODS steel after high temperature oxidation indicated the surface oxidation film of ODS steel had the remark change with prolonged oxidation time. The compactness of oxidation film of ODS steel increased with higher Cr contents. The weight of ODS steel increased with increasing oxidation time. While the weight increase of ODS steel was not obvious and more decreased after long time.