碳钢在碱性溶液中的孔蚀电位与HCO_3^-/Cl^-比值关系的研究  

Relationship Between Pitting Potential of Carbon Steel with Ratio of HCO_3^-/Cl^- in Alkaline Solution

作　　者：林冰[1] 王怡珊[1] 王佳妮[1] 左禹[1] 唐聿明[1] 

机构地区：[1]北京化工大学材料科学与工程学院材料电化学过程与技术北京市重点实验室,北京100029

出　　处：《腐蚀科学与防护技术》2016年第2期135-138,共4页Corrosion Science and Protection Technology

基　　金：国家自然科学基金项目(51171014和51210001)资助

摘　　要：研究了Na HCO3+Na Cl碱性溶液中,较宽Cl-浓度(0.001~0.3 mol/L)范围内Cl-浓度及HCO_3^-和Cl-的浓度比值([HCO_3^-]/[Cl-])对Q235碳钢小孔腐蚀电位的影响。结果表明,Cl-浓度较大(>0.02 mol/L)时,碳钢的稳定孔蚀电位Eb和亚稳态孔蚀电位Em都与[HCO_3^-]/[Cl-]符合很好的线性关系,[HCO_3^-]/[Cl-]升高Eb和Em线性增大;当Cl-浓度较小(<0.02 mol/L)时,Eb和Em与[HCO_3^-]/[Cl-]之间不存在良好的线性关系,该条件下碳钢表面在发生稳定孔蚀前观察不到微米级的亚稳态小孔。The influence of Cl^-concentration and the concentration ratio of HCO3^-to Cl^-（[HCO3^-]/[Cl^-]） in Na HCO3＋Na Cl alkaline solution on the pitting potentials of Q235 carbon steel was studied in a chloride ion concentration range from 0.001 to 0.3 mol/L. It was found that when the Cl^-concentration is higher than 0.02 mol/L, good linear relationship exists not only between the pitting potential Eband [HCO3^-]/[Cl^-] but also between the meatstable pitting potential Emand [HCO3^-]/[Cl^-],that is Eband Emincrease linearly with the increase of [HCO3^-]/[Cl^-]. When the Cl^-concentration is lower than 0.02 mol/L, [HCO3^-]/[Cl^-] is not linear with Eband Em, and under these conditions, no micron scale metastable pits can be observed on the steel surface before the occurence of stable pits.

关 键 词：碳钢 亚稳态孔蚀 孔蚀电位 Cl^- HCO3^- 

分 类 号：TG172[金属学及工艺—金属表面处理]