氢和应力对阳极溶解的影响  

EFFECT OF HYDROGEN AND STRESS ON ANODIC DISSOLUTION

作　　者：胡小丽[1] 黄震中[1] 乔利杰[1] 褚武扬[1] 

机构地区：[1]北京科技大学

出　　处：《中国腐蚀与防护学报》1996年第3期187-194,共8页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金

摘　　要：在五种恒电位下研究了氢和应力单独存在或同时存在对１ｍｏｌ／ＬＮＨ４ＮＯ３溶液中低碳钢溶解速率及交流阻抗的影响。结果表明，当电位处于活化区时，预充氢试样的溶解速率比未充氢试样的要低，其界面电阻也比后者的大。如电位控制在过渡区，钝化区或过钝化区，则预充氢能明显促进阳极溶解，界面电阻也明显降低。氢的这种影响是多个因素叠加的结果。氢降低自由能使溶解速率升高（约１０％）；充氢表面局部酸化，而腐蚀电位并不改变，从而导致溶解速率降低；氢阻碍钝化膜形成或促进其破裂从而使阳极溶解速率大幅度提高。在活化区施加大于屈服值的恒应力，仅使溶解速率升高约２％；但在过渡区则可使溶解速率升高３０～７０％。氢和应力存在协同作用。在活化区，它主要归因于氢和应力之间存在互作用能；而在过渡区，协同作用主要反映在氢和应力同时存在能阻碍钝化膜形成；在钝化区或过钝化区，反映在促使钝化膜破裂。ffects of hydrogen and stress on anodic dissolution for mild steel in 1 mol/L NH4NO3 solution were investigated under various potentials corresponding to active, active-passive transition, passive and transpassive regions respectively on the polarization curve. The results showed that hydrogen decreased the dissolution rate in the active region but increased the rate in the passive and transpassive regions and increased the rate tremendously in the active-passive transition region. They were consistant with the effects of hydrogen on electrochemical impedance. Constant stress σ=1.1 σys increased the dissolution rate only by 2% in the active region but 30～70% in the active-passive transition region. The effects of hydrogen and stress on the dissolution rate were synergistic rather than simply additive and the effect in the transition region was far greater than that in the active region.

关 键 词：氢 应力 低碳钢 阳极溶解 

分 类 号：TG172[金属学及工艺—金属表面处理]