第8期 肖葵等：扫描Kelvin探针研究破损环氧涂层下碳钢的腐蚀行为 ·977 积聚，且与有机涂层的亲水组分作用，导致有机涂层 als covered with adsorbed electrolyte layers a new experimental 发生溶胀.随着有机涂层渗入通道不断扩大并发生 technique.Corros Sci,1987,27(8):869 6 连通，增大了界面处和溶液之间的渗透压，腐蚀性介 Stratmann M,Leng A,Fuirbeth W,et al.The scanning Kelvin probe:a new technique for the in situ analysis of the delamination 质逐渐聚集在有机涂层/金属基体的缺陷处.腐蚀 of organic coatings.Prog Org Coat,1996,27(1-4):261 产物不断地在有机涂层/金属基体界面处集聚，从而 7]Hoffmann K,Stratmann M.The delamination of organic coatings 导致体积膨胀向外起泡，鼓泡通过长大和交联，最终 from rusty steel substrates.Corros Sci,1993,34(10):1625 导致涂层全面的破损失效.涂层破损区域不仅为盐 8] Leng A,Streckela H,Stratmann M.The delamination of polymer- 溶液渗入提供了更多的通道，而且与其周围完好涂 ic coatings from steel:Part 1.Calibration of the Kelvinprobe and basic delamination mechanism.Corros Sci,1998,41(3):547 层区域形成显著的伏打电位差，为膜下腐蚀的进一 [9]Leng A,Streckela H,Stratmann M.The delamination of polymer- 步发展提供了驱动力 ic coatings from steel:Part 2.First stage of delamination,effect of type and concentration of canons on delamination,chemical analy- 4结论 sis of the interface.Corros Sci,1998.41(3):579 (1)在盐雾腐蚀初期，因为有机涂层缺陷处的 [10]Leng A,Streckela H,Hofmann K,et al.The delamination of polymeric coatings from steel:Part 3.Effect of the oxygen partial 电位较周围的涂层金属更负，所以作为阳极发生溶 pressure on the delamination reaction and current distribution at 解：而邻近的膜下基体为阴极，发生氧去极化反应 the metal/polymer interface.Corros Sci,1998,41(3):599 (2)当盐雾试验进行一定时间后，在划痕缺陷 n1] Doherty M,Sykes J M.Micro-cells beneath organic lacquers:a 处生成的未溶腐蚀产物覆盖了裸露的基体，该腐蚀 study using scanning Kelvin probe and scanning acoustic micros- 产物与溶液中的氧反应转变为FOOH.当划痕缺陷 copy.Corros Sci,2004,46(5):1265 [12]Reddy B.Doherty M J,Sykes J M.Breakdown of organic coat- 处产生的F0OOH腐蚀产物作为阴极产物被还原为 ings in corrosive environments examined by scanning Kelvin probe Fe3O,时，原来的划痕缺陷处电位变正，缺陷附近的 and scanning acoustic microscopy.Electrochim Acta,2004,49 膜下基体电位变负，从而形成了新的阴极和阳极区， (17118):2965 新的阴极和阳极的电位差是膜下腐蚀发展的驱 [13]Reddy B,Sykes J M.Degradation of organic coatings in a corro- 动力 sive environment:a study by scanning Kelvin probe and scanning (3)随着膜下腐蚀的进行，有机涂层与宏观缺 acoustic microscope.Prog Org Coat,2005,52(4):280 [14] Fu A Q,Cheng Y F.Characterization of corrosion of X65 pipe- 陷相互交联，形成腐蚀介质的传输通道，并在界面处 line steel under disbonded coating by scanning Kelvin probe. 产生大量的腐蚀产物，加上渗透压的作用，会破坏涂 Corros Sci,2009,51(4):914 层与金属的结合力，使有机涂层保护性能变差，从而 [15]Dong C F,Sheng H,An Y H,et al.Corrosion of 7A04 alumi- 会发生鼓泡，甚至剥离现象 num alloy under defected epoxy coating studied by localized elec- trochemical impedance spectroscopy.Prog Org Coat,2010,67 (3):269 参考文献 [16]Fuirbeth W,Stratmann M.Investigation of the delamination of [Grundmeier G,Schmidt W,Stratmann M.Corrosion protection by polymer films from galvanized steel with the scanning Kelvin- organic coatings:electrochemical mechanism and novel methods of probe.Fresenius J Anal Chem,1995,353 (3/4)337 investigation.Electrochim Acta,2000,45(15/16)2515 17] Fuirbeth W,Stratmann M.The delamination of polymeric coatings 2]Bastidas J M,Morcillo M,Rodriguez F J.Mild steel corrosion in from electrogalvanized steel:a mechanistic approach.Part 1.De- saline solutions:comparison between bulk solutions and steel-coat- lamination from a defect with intact zinc layer.Corros Sci,2001, ing interfacial solutions.J Coat Technol,1998,70(882):61 43:207 B] Morcillo M.Soluble salts:their effects on premature degradation of 18J Schmidt W,Stratmann M.Scanning Kelvinprobe investigations of anticorrosive paints.Prog Org Coat,1999,36(3):137 filiform corrosion on aluminium alloy 2024-13.Corros Sci,1998, 4]Morcillo M,Rodriguez F J,Bastidas J M.The influence of chlo- 40(8):1441 rides,sulphates and nitrates at the coating-steel interface on un- [19]de Wit J H W.New knowledge on localized corrosion obtained derfilm corrosion.Prog Org Coat,1997,31(3):245 from local measuring techniques.Electrochim Acta,2001,46 [5] Stratmann M.The investigation of the corrosion properties of met- (24/25):3641第 8 期 肖 葵等: 扫描 Kelvin 探针研究破损环氧涂层下碳钢的腐蚀行为 积聚，且与有机涂层的亲水组分作用，导致有机涂层 发生溶胀． 随着有机涂层渗入通道不断扩大并发生 连通，增大了界面处和溶液之间的渗透压，腐蚀性介 质逐渐聚集在有机涂层/金属基体的缺陷处． 腐蚀 产物不断地在有机涂层/金属基体界面处集聚，从而 导致体积膨胀向外起泡，鼓泡通过长大和交联，最终 导致涂层全面的破损失效． 涂层破损区域不仅为盐 溶液渗入提供了更多的通道，而且与其周围完好涂 层区域形成显著的伏打电位差，为膜下腐蚀的进一 步发展提供了驱动力． 4 结论 ( 1) 在盐雾腐蚀初期，因为有机涂层缺陷处的 电位较周围的涂层金属更负，所以作为阳极发生溶 解; 而邻近的膜下基体为阴极，发生氧去极化反应． ( 2) 当盐雾试验进行一定时间后，在划痕缺陷 处生成的未溶腐蚀产物覆盖了裸露的基体，该腐蚀 产物与溶液中的氧反应转变为 FeOOH． 当划痕缺陷 处产生的 FeOOH 腐蚀产物作为阴极产物被还原为 Fe3O4 时，原来的划痕缺陷处电位变正，缺陷附近的 膜下基体电位变负，从而形成了新的阴极和阳极区， 新的阴极和阳极的电位差是膜下腐蚀发展的驱 动力． ( 3) 随着膜下腐蚀的进行，有机涂层与宏观缺 陷相互交联，形成腐蚀介质的传输通道，并在界面处 产生大量的腐蚀产物，加上渗透压的作用，会破坏涂 层与金属的结合力，使有机涂层保护性能变差，从而 会发生鼓泡，甚至剥离现象． 参 考 文 献 ［1］ Grundmeier G，Schmidt W，Stratmann M． Corrosion protection by organic coatings: electrochemical mechanism and novel methods of investigation． Electrochim Acta，2000，45( 15 /16) : 2515 ［2］ Bastidas J M，Morcillo M，Rodriguez F J． Mild steel corrosion in saline solutions: comparison between bulk solutions and steel-coat￾ing interfacial solutions． J Coat Technol，1998，70( 882) : 61 ［3］ Morcillo M． Soluble salts: their effects on premature degradation of anticorrosive paints． Prog Org Coat，1999，36( 3) : 137 ［4］ Morcillo M，Rodríguez F J，Bastidas J M． The influence of chlo￾rides，sulphates and nitrates at the coating-steel interface on un￾derfilm corrosion． Prog Org Coat，1997，31( 3) : 245 ［5］ Stratmann M． The investigation of the corrosion properties of met￾als covered with adsorbed electrolyte layers a new experimental technique． Corros Sci，1987，27( 8) : 869 ［6］ Stratmann M，Leng A，Fürbeth W，et al． The scanning Kelvin probe: a new technique for the in situ analysis of the delamination of organic coatings． Prog Org Coat，1996，27( 1 － 4) : 261 ［7］ Hoffmann K，Stratmann M． The delamination of organic coatings from rusty steel substrates． Corros Sci，1993，34( 10) : 1625 ［8］ Leng A，Streckela H，Stratmann M． The delamination of polymer￾ic coatings from steel: Part 1． Calibration of the Kelvinprobe and basic delamination mechanism． Corros Sci，1998，41( 3) : 547 ［9］ Leng A，Streckela H，Stratmann M． The delamination of polymer￾ic coatings from steel: Part 2． First stage of delamination，effect of type and concentration of canons on delamination，chemical analy￾sis of the interface． Corros Sci，1998，41( 3) : 579 ［10］ Leng A，Streckela H，Hofmann K，et al． The delamination of polymeric coatings from steel: Part 3． Effect of the oxygen partial pressure on the delamination reaction and current distribution at the metal /polymer interface． Corros Sci，1998，41( 3) : 599 ［11］ Doherty M，Sykes J M． Micro-cells beneath organic lacquers: a study using scanning Kelvin probe and scanning acoustic micros￾copy． Corros Sci，2004，46( 5) : 1265 ［12］ Reddy B，Doherty M J，Sykes J M． Breakdown of organic coat￾ings in corrosive environments examined by scanning Kelvin probe and scanning acoustic microscopy． Electrochim Acta，2004，49 ( 17 /18) : 2965 ［13］ Reddy B，Sykes J M． Degradation of organic coatings in a corro￾sive environment: a study by scanning Kelvin probe and scanning acoustic microscope． Prog Org Coat，2005，52( 4) : 280 ［14］ Fu A Q，Cheng Y F． Characterization of corrosion of X65 pipe￾line steel under disbonded coating by scanning Kelvin probe． Corros Sci，2009，51( 4) : 914 ［15］ Dong C F，Sheng H，An Y H，et al． Corrosion of 7A04 alumi￾num alloy under defected epoxy coating studied by localized elec￾trochemical impedance spectroscopy． Prog Org Coat，2010，67 ( 3) : 269 ［16］ Fürbeth W，Stratmann M． Investigation of the delamination of polymer films from galvanized steel with the scanning Kelvin￾probe． Fresenius J Anal Chem，1995，353( 3 /4) : 337 ［17］ Fürbeth W，Stratmann M． The delamination of polymeric coatings from electrogalvanized steel: a mechanistic approach． Part 1． De￾lamination from a defect with intact zinc layer． Corros Sci，2001， 43: 207 ［18］ Schmidt W，Stratmann M． Scanning Kelvinprobe investigations of filiform corrosion on aluminium alloy 2024-T3． Corros Sci，1998， 40( 8) : 1441 ［19］ de Wit J H W． New knowledge on localized corrosion obtained from local measuring techniques． Electrochim Acta，2001，46 ( 24 /25) : 3641 ·977·