氯离子对吉林地区镀锌钢和不锈钢土壤腐蚀行为的影响

    Effect of Chloride Ion on Soil Corrosion Behavior of Galvanized Steel and Stainless Steel in Jilin Region

    • 摘要: 氯离子(Cl-)是导致土壤金属腐蚀最重要的阴离子。通过室内模拟加速试验探索Cl-的土壤腐蚀规律和不同金属在暗棕壤中的耐腐蚀性能,采用X射线衍射仪、X射线光电子能谱仪、金相显微镜和扫描电子显微镜分析金属腐蚀产物形貌和组成的变化。结果表明:Cl-被吸附在镀锌钢表面促进腐蚀,导致Fe2+溶出;当Cl-含量为2.0 mg/g时,镀锌钢的自腐蚀电流密度(Icorr)为78.361μA·cm-2,腐蚀最严重;Cl-置换不锈钢表面不稳定的O原子,形成原电池,促进不锈钢的蚀坑形成。当埋片试验为42 d时,镀锌钢表面腐蚀产物主要为Fe3O4、FeOOH和Fe2O3。与镀锌钢相比,不锈钢有更大的电容弧和更高的腐蚀电位,耐腐蚀性能强,镀锌钢的腐蚀速率比不锈钢高20多倍。

       

      Abstract: Chloride ion(Cl-) is the most important anion that causes soil metal corrosion. The soil corrosion law of Cl-and the corrosion resistance of different metals in dark brown forest soil were explored using indoor simulated acceleration experiments. The morphologies and composition changes of metal corrosion products were analyzed using X-ray diffraction,X-ray photoelectron spectroscopy, metallographic microscope and scanning electron microscope. The results show that Cl-is adsorbed on the surface of galvanized steel to promote corrosion, leading to the dissolution of Fe2+. When the content of Cl-is2.0 mg/g, the self-corrosion current density Icorrof galvanized steel is 78.361 μA·cm-2and the corrosion is the most severe. Cl-promote the formation of corrosion pits in stainless steel by replacing unstable O atoms on the surface, and thus a primary battery is formed. When the buried sheet test is carried out for 42 d, the surface corrosion products of galvanized steel are mainly Fe3O4, FeOOH and Fe2O3. Compared with the galvanized steel, the stainless steel has a larger capacitance arc and higher self-corrosion potential, and it is more resistant to corrosion. The corrosion rate of the galvanized steel is 20 times higher than that of stainless steel.

       

    /

    返回文章
    返回