Cl^-浓度对HPB300钢筋在模拟混凝土孔隙液中腐蚀行为的影响

Influence of Cl^- on Corrosion Behavior of Steel HPB300 in Simulated Concrete Pore Solution

采用自然腐蚀、线性极化、动电位极化、SEM扫描电镜和X射线衍射等方法研究了模拟混凝土孔隙液中Cl-含量对HPB300钢筋腐蚀行为的影响。结果表明,Cl-是引发钢筋锈蚀的重要因素,随着Cl-浓度增加,自然腐蚀电位逐渐负移,当Cl-摩尔浓度达到0.25mol/L时,自腐蚀电位基本不受Cl-浓度影响;线性极化电阻Rp逐渐减小;动电位极化阳极区钝化区电位范围逐渐变窄,过钝化电位由0.6V(SCE,下同)左右逐渐负移至-0.3V左右;腐蚀产物主要为FeO(OH)和FeCl2,产物膜孔隙率减小,微观形貌由片状变为块状。

Free corrosion, liner polarization, potentiodynamic polarization, SEM and XRI） were used to investigate the influence of Cl on the corrosion behavior of slecl HPB300 in simulated concrete pore solution. The results indicate that Cl is an important factor causing steel to corrosion. With the increase of Cl concentration, free corrosion potential changed negatively, and seawater concentration did not affect the stable free corrosion potential when d^e c（mcentration of Cl reached 0. 25 moi/I.; linear polarization resistance R,, decreased gradually, anodic passive range of potentiodynamic polarization narrowed gradually, breakdown potential changed negatively from 0.6 V to -0.3 V（SCE）. The main corrosion products were FcO（OH） and FeCl2, and the porosity reduced, micro morphology shape changed from sheet into massive shape.