D0I:10.13374f.issn1001-053x.2011.08.012 第33卷第8期 北京科技大学学报 Vol.33 No.8 2011年8月 Journal of University of Science and Technology Beijing Aug.2011 扫描Kelvin 探针研究破损环氧涂层下碳钢的腐蚀 行为 肖葵)四董超芳) 魏丹2》吴俊升”徐龙娇”李晓刚” 1)北京科技大学腐蚀与防护中心，北京1000832)中国科学技术协会学会展务管理中心，北京100081 ☒通信作者，E-mail:xiaokui(@sina.com 摘要采用扫描Kvim探针技术(SKP)对中性盐雾环境条件下破损环氧涂层的碳钢的腐蚀行为进行了研究.不同盐雾试 验阶段的伏打电位变化规律的分析结果表明：环氧/碳钢涂层的缺陷为腐蚀介质提供了向碳钢基体传输的通道.破损处碳钢 基体的电位比其邻近的膜下碳钢基体更负，成为阳极溶解发生区域.一定时间的盐雾试验后，破损处生成的未溶腐蚀产物可 覆盖住裸露基体，使破损处向正的电位变化而成为阴极，而其附近的膜下碳钢基体电位变负而成为新的阳极区.同时，不断形 成的新阴极和新阳极的电位差成为膜下腐蚀继续发展的驱动力.随着膜下腐蚀的进行，腐蚀介质和腐蚀产物在界面处大量聚 集，破坏了环氧和碳钢基体的结合力，导致鼓泡和剥离现象的出现. 关键词碳钢：环氧树脂：涂层：腐蚀：扫描Kelvin探针 分类号TG172.3 Corrosion behavior of carbon steel undera defected epoxy coating studied by scanning Kelvin probe XIAO Kui,DONG Chaofang",WEI Dan2,WU Jun-sheng",XU Longjiao,LI Xiao-gang" 1)Corrosion and Protection Center,University of Science and Technology Beijing,Beijing 100083,China 2)Society Service Center,China Association for Science and Technology,Beijing 100081,China Corresponding author,E-mail:xiaokui@sina.com ABSTRACT Scanning Kelvin probe (SKP)was used for measuring the corrosion behavior of carbon steel with a defected epoxy coat- ing after neutral salt spray test,and the volta potential changes of carbon steel at different stages of neutral salt spray test were ana- lyzed.It is shown that the defect formed by the damaged epoxy/carbon coating provides a way for the corrosive medium to contact the carbon steel matrix.The potential of carbon steel is more negative at the defect point than that under the coating,resulting in anodic dissolution at the defect point.After some time of neutral salt spray test,insoluble corrosion products can cover the bare defect,leading to the potential at this part shifting to more positive values.Consequently,the defect becomes a cathode,while its vicinity under the coating exists as an anode.Meanwhile,the potential difference between the new cathode and the new anode offers a driving force for continuous corrosion under the coating.Therefore,with the corrosion developing,there would be a considerable corrosive medium and corrosion products aggregating at the interface,which destroy the binding between the epoxy coating and carbon steel,leading to the ap- pearances of bubbling and peeling. KEY WORDS carbon steel;epoxy resins:coatings:corrosion:scanning Kelvin probe 有机涂层/金属存在的孔、裂纹或裂缝等宏观缺 气腐蚀的研究中，从而发展了一种薄液膜下电化学 陷贯穿整个有机涂层时，将会为腐蚀性介质传输到 测量的新技术.Stratmann等6-采用Kelvin探针测 金属基体提供通道，从而导致金属基体将在这些缺 量技术原位测量人造缺陷处离子沿有机涂层/金属 陷的位置发生腐蚀-.20世纪80年代，Sat- 界面扩散和剥落过程，表明在缺陷涂层/金属界面形 mann首先将Kelvin探针测量技术应用到金属大 成腐蚀原电池而产生的电位差成为剥落的驱动力 收稿日期：20100806 基金项目：国家自然科学基金面上项目(50871021：50701006)第 33 卷 第 8 期 2011 年 8 月 北京科技大学学报 Journal of University of Science and Technology Beijing Vol． 33 No． 8 Aug． 2011 扫描 Kelvin 探针研究破损环氧涂层下碳钢的腐蚀 行为 肖 葵1)  董超芳1) 魏 丹2) 吴俊升1) 徐龙娇1) 李晓刚1) 1) 北京科技大学腐蚀与防护中心，北京 100083 2) 中国科学技术协会学会服务管理中心，北京 100081  通信作者，E-mail: xiaokui@ sina． com 摘 要 采用扫描 Kelvin 探针技术( SKP) 对中性盐雾环境条件下破损环氧涂层的碳钢的腐蚀行为进行了研究． 不同盐雾试 验阶段的伏打电位变化规律的分析结果表明: 环氧/碳钢涂层的缺陷为腐蚀介质提供了向碳钢基体传输的通道． 破损处碳钢 基体的电位比其邻近的膜下碳钢基体更负，成为阳极溶解发生区域． 一定时间的盐雾试验后，破损处生成的未溶腐蚀产物可 覆盖住裸露基体，使破损处向正的电位变化而成为阴极，而其附近的膜下碳钢基体电位变负而成为新的阳极区． 同时，不断形 成的新阴极和新阳极的电位差成为膜下腐蚀继续发展的驱动力． 随着膜下腐蚀的进行，腐蚀介质和腐蚀产物在界面处大量聚 集，破坏了环氧和碳钢基体的结合力，导致鼓泡和剥离现象的出现． 关键词 碳钢; 环氧树脂; 涂层; 腐蚀; 扫描 Kelvin 探针 分类号 TG172. 3 Corrosion behavior of carbon steel undera defected epoxy coating studied by scanning Kelvin probe XIAO Kui 1)  ，DONG Chao-fang1) ，WEI Dan2) ，WU Jun-sheng1) ，XU Long-jiao 1) ，LI Xiao-gang1) 1) Corrosion and Protection Center，University of Science and Technology Beijing，Beijing 100083，China 2) Society Service Center，China Association for Science and Technology，Beijing 100081，China  Corresponding author，E-mail: xiaokui@ sina． com ABSTRACT Scanning Kelvin probe ( SKP) was used for measuring the corrosion behavior of carbon steel with a defected epoxy coat￾ing after neutral salt spray test，and the volta potential changes of carbon steel at different stages of neutral salt spray test were ana￾lyzed． It is shown that the defect formed by the damaged epoxy /carbon coating provides a way for the corrosive medium to contact the carbon steel matrix． The potential of carbon steel is more negative at the defect point than that under the coating，resulting in anodic dissolution at the defect point． After some time of neutral salt spray test，insoluble corrosion products can cover the bare defect，leading to the potential at this part shifting to more positive values． Consequently，the defect becomes a cathode，while its vicinity under the coating exists as an anode． Meanwhile，the potential difference between the new cathode and the new anode offers a driving force for continuous corrosion under the coating． Therefore，with the corrosion developing，there would be a considerable corrosive medium and corrosion products aggregating at the interface，which destroy the binding between the epoxy coating and carbon steel，leading to the ap￾pearances of bubbling and peeling． KEY WORDS carbon steel; epoxy resins; coatings; corrosion; scanning Kelvin probe 收稿日期: 2010--08--06 基金项目: 国家自然科学基金面上项目( 50871021; 50701006) 有机涂层/金属存在的孔、裂纹或裂缝等宏观缺 陷贯穿整个有机涂层时，将会为腐蚀性介质传输到 金属基体提供通道，从而导致金属基体将在这些缺 陷的位置发生腐蚀［1--4］． 20 世 纪 80 年 代，Strat￾mann ［5］首先将 Kelvin 探针测量技术应用到金属大 气腐蚀的研究中，从而发展了一种薄液膜下电化学 测量的新技术． Stratmann 等［6--7］采用Kelvin探针测 量技术原位测量人造缺陷处离子沿有机涂层/金属 界面扩散和剥落过程，表明在缺陷涂层/金属界面形 成腐蚀原电池而产生的电位差成为剥落的驱动力． DOI:10.13374/j.issn1001-053x.2011.08.012