不同状态的钢筋在氯离子入侵过程中的腐蚀行为

摘要

采用极化曲线技术和扫描电镜结合能谱分析，对供货状态和打磨光滑状态的钢筋在混凝土氯离子侵蚀过程中的腐蚀行为进行了研究。通过不同浸泡时间，试样获得了不同的自腐蚀电位及自腐蚀电流密度，分析了不状态试样的表面形貌。结果表明，由于钢筋表面状态不同，钢筋在混凝土中的不同阶段表现出不同的电化学行为。在初期无氯离子的条件下，不同表面状态的钢筋表面钝化膜的稳定性不同，而随着氯离子在混凝土中的入侵，两种钢筋的腐蚀速率也存在很大的差异。结合表面状态分析表明，供货状态钢筋在混凝土氯离子入侵过程中比打磨光滑状态钢筋更易发生腐蚀。%The corrosion behavior of reinforced steel with different surface states in steel bar immersed in simulated solution containing Cl- was investigated by electrochemical measurements,scanning electron microscopy with energy dispersive X-ray spectrometer (SEM/EDX).The changes of corrosion potential and corrosion current density of reinforced steel with the immersion time were obtained,and the morphology of samples with different surface states was analyzed.The results show that the corrosion behavior of reinforced concrete was different in different immersion stages.The stability of passive film formed on the polished steel was better than that of as-supplied steel at the initial stage was when Cl- did not reach the surface of steel.The corrosion rate of as-supplied steel was larger than that of polished steel with the increase of Cl- ions on the surface of steel due to the rough surface caused by thermal oxidation in manufacture process.