阳极时效时间与电解质对Fe—31Mn—7Cr合金钝化膜的稳定性与耐腐蚀性能的影响

运用综合的电化学方法与原子吸收光谱技术，研究阳极时效时间及其电解液对Fe-31Mn-7Cr合金于50％HNO3或1molL^-1Na2SO4溶液中形成的钝化膜的稳定性与耐蚀性的影响。在阳极钝化电位中区，延长Fe-32Mn-7Cr合金在50％HNO3或1molL^-1Na2SO4水溶液中阳极时效时间能增加钝化膜的稳定性与防护性，随之进一步改善合金的耐腐蚀抗力。由1molL^-1Na2SO4水溶液中阳极极化曲线各参数所表征的Fe-31Mn-7Cr(经1molL^-1Na2SO4阳极时效5h后）的耐腐蚀性能接近于1Cr13不锈钢的水平。在强氧化性的50％HNO3溶液中阳极时效表面改性的效果明显优于在中性的1molL^-1Na2SO4溶液中改性。表面改性后，抗腐蚀性能的提高主要归因于钝化膜中Cr氧化物的富集与Fe和Mn氧化物的贫乏。

Effects of Anodic Aging Time and Electrolyte on the Stability and Resistance to Corrosion of Passive Film Formed on an Fe-31Mn-7Cr alloy

The effects of anodic aging time and electrolyte on the stability and corrosion resistance of the passive film formed on an Fe-31Mn-7Cr alloy in 50%HNO3 solution or 1mol L-1Na2SO4 solution were investigated by using combined electrochemical measurements and atomic absorption spectrophotometry. In the anodic passive region, protonged anodic aging time for Fe-31Mn-7Cr alloy in 50 %HNO3 solution or 1mol L-1Na2SO4 solution can induce an increase in stability and protection of the passive film, and then further improves resistance to corrosion. The corrosion resistance characterized by anodic polarization curve in 1mol L-1Na2SO4 solution of Fe-31Mn-7Cr altoy after anodic aging in 1molL-1Na2SO4 solution for 5h is approximate to that of the 1Cr13 stainless steel. The surface modification action of anodic aging in oxidiaing 50 %HNO3 solution is superior to that of anodic aging in neutral 1molL-1Na2SO4 solution. The increase of resistance to corrosion is mainly attributed to Cr oxides enrichment and oxides of Fe and Mn depletion in the passive film.