Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract： Serious corrosion problem could be found in the vicinity of the interface sea-water/seamud (VISS) for marine structures of steels. The corrosion of carbon steel in an artificial environment as a simulation of the above VISS was studied by means of wire beam electrode (WBE) technique, linear polarization (LP) technique, electrochemical impedance spectroscopy (EIS) and corrosion morphology examination etc. For the simulated VISS, the sea- water and sea- mud were taken directly from Zhanjiang bay of the South China sea. The galvanic current between one electrode and another electrode among the rest 99 electrodes was successively measured by WBE technique, and the change of the cathode area and anode area was acquired from the results of the measurement of galvanic current. The Ecorr and Icorr of the electrodes of carbon steel, which were perpendicular to the interface of sea-water/sea-mud (ISS), were obtained by the linear polarization technique. Then the corrosion morphology of the tested electrodes was observed by stereo microscope. The results show that the portion under ISS of an immersed electrode of carbon steel acts as anode, and that above ISS acts as cathode. The corrosion of carbon steel in the VISS was controlled by the potential difference, the dissolve oxygen concentration and the sea-mud impedance. The areas both of where near by the ISS on the anode portion and where far from the ISS on the cathode portion were the serious corrosion areas. Correspondingly of which the formed corrosion product on the former was fluffy and low adhesive, while that on the later was compact and strongly adhesive.
Subjects: Geosciences >> Marine Sciences Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract：由于土壤成分的非均匀性，决定土壤中金属易发生非均匀腐蚀。本文利用阵列电极技术与腐蚀埋片相结合的方法，以碳钢Q235为研究材料，经自然热带临海红壤埋片，研究了碳钢Q235的宏观非均匀腐蚀行为。碳钢Q235材料在时间维度上和垂直地面的空间维度上皆发生非均匀腐蚀。时间维度上发生非均匀腐蚀的原因是降雨频率与降雨量对土壤湿度的影响，从而影响碳钢Q235材料腐蚀的环境；垂直地面的空间维度上发生非均匀腐蚀的原因是随土壤深度增加，土壤湿度变化、含氧量变化及土壤组成成分差异的影响。在0-90cm深度土壤范围内，随土壤深度的增加，碳钢Q235材料的腐蚀速率增加。垂向埋于热带滨海红壤中的长尺寸碳钢Q235材料在30cm-50cm、80cm和 140cm-150cm三个范围内，因电偶腐蚀影响，腐蚀速率较大。
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