Under the immersed and wet-dry cyclic conditions,the deterioration processes of the organic coatings on carbon steel surface have been comparatively studied by using electrochemical techniques.The wet-dry cycles were carried out in the alternating conditions of 12 h by immersing in a 3.5% sodium chloride solution and drying at 25 ℃ and 50% RH.Coating resistance,Rf,coating capacitance,Cf,and double layer capacitance,Cd,were monitored continuously and separately under above two conditions.The percentages of the intenfacial active area,Aw,were estimated from the obtained double layer capacitance,Cd.According to the EIS characteristics,the entire deterioration processes under above two mentioned conditions can be divided into three main stages,consisting of the medium penetration into coatings,corrosion initiation and corrosion extension underlying coatings.Comparing with the immersed,the cyclic wet-dry greatly accelerated the corrosion initiation stage,but decelerated the medium penetration and corrosion extension underlying coatings stages.The acceleration mechanism of the coatings and underlying metal corrosion under wet-dry cycles was discussed based on above results.


organic coatings, wet-dry cycles, electrochemical impedance spectroscopy

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[1]ZHAO Zengyuan(赵增元),KONG Aimin(孔爱民),WANG Jia(王佳),et al.Study of the influence of wet-dry cycle in splashing and tidal zone on degradation oforganic coatings[J].Shipbuilding of China,2008,49:336-331.
[2]Destreri MD G,Vogelsang J,Fedrizzi L,et al.Water up-take evaluation of new waterborne and high solid epoxycoatings[J].Prog Org Coat,1999,37:69-81.
[3]Yang X F,Tallman D E,Croll S G,et al.Morphologicalchanges in polyurethane coatings on exposure to water[J].Polym Degrad Stab,2002,77:391-396.
[4]Park J H,Lee G D,Ooshige H,et al.Monitoring of wateruptake in organic coatings under cyclic wet-dry condi-tion[J].Corr Sci,2003,45:1881-1894.
[5]Stratmann M,Streckel H,Kim K T,et al.On the atmos-pheric corrosion of metals which are covered with thin e-lectrolyte layers-iii.the measurement of polarisationcurves on metal surfaces which are covered by thin elec-trolyte layers[J].Corr Sci,1990,30:715-734.
[6]Leng A,Streckel H,Stratmann M.The delamination ofpolymeric coatings from steel.Part 3:Effect of the oxy-gen partial pressure on the delamination reaction andcurrent distribution at the metal/polymer interface[J].Corr Sci,1999,41:599-620.
[7]Furbeth W,Stratmann M.The delamination of polymericcoatings from electrogalvanised steel-a mechanistic ap-proach.Part 1:delamination from a defect with intactzinc layer[J].Corr Sci,2001,43:207-227.
[8]Bierwagen G,Allahar K,Hinderliter B,et al.Ionic liquidenhanced electrochemical characterization of organiccoatings[J].Progress in Organic Coatings,2008,63:250-259.
[9]Lendvay-Gyorik G,Pajkossy T,Lengyel B.Corrosion-protection properties of water-borne paint coatings asstudied by electrochemical impedance spectroscopy andgravimetry[J].Prog Org Coat,2006,56:304.
[10]Tomashov N D.Development of the electrochemicaltheory of metallic corrosion[J].Corrosion,1964,20:7t-14t.
[11]Tsuru T,Nishikata A,Wang J.Electrochemical studieson corrosion under a water film[J].Mater Sci Eng,1995,A198:161-168.
[12]Mansfeld F.Corrosion Processes[M].London:Ap-plied Science Publishers,1982.
[13]Wang J(王佳),Tsuru T(水流彻).An investigationon oxygen reduction under thin electrolyter layer usingkelvin probe reference electrode[J].Journal of Chi-nese Society Corrosion Protection(中国腐蚀与防护学报),1995,15(3):180-188.
[14]Zhang Jian-qing(张鉴清),Cao Chu-nan(曹楚南).Study and evaluation on coatings by electrochemicalimpedance spectroscopy[J].Corrosion and Protection(腐蚀与防护),1998,19(3):99-104.
[15]Gao Zhi-ming(高志明),Song Shi-zhe(宋诗哲),XuYunhai(徐云海).Electrochemical impedance spec-troscope analysis of coating deterioration process withKohonen neural networks[J].Journal of Chinese So-ciety Corrosion Protection(中国腐蚀与防护学报),2005,25:106-109.
[16]Zhao X,Wang J,Wang Y H,et al.Analysis of deterio-ration process of organic protective coating using EISassisted by SOM network[J].Electrochem Commun,2007,9:1394-1399.
[17]Zhang Wei(张伟),Wang Jia(王佳),Zhao Zeng-yuan(赵增元),et al.Study on deterioration processof organic coatings by EIS and SKP[J].ChemicalJournal of Chinese Universities(高等学校化学学报),2009,30:762-766.
[18]Howard R L,Lyon S B,Scantlebury J D.Acceleratedtests for prediction of cut edge corrosion of coil-coatedarchitectural cladding.Part II:cyclic immersion[J].Prog Org Coat,1999,37:99-106.
[19]Gamal A,El-Mahdy,Nishikata A,et al.Electrochemi-cal corrosion monitoring of galvanized steel under cy-clic wet-dry conditions[J].Corr Sci,2000,42:183-194.
[20]Gamal A,EL-Mahdy.Atmospheric corrosion of copperunder wet/dry cyclic conditions[J].Corr Sci,2005,47:1370-1383.
[21]Deflorian F,Fedrizzi L,Rossi S,et al.Organic coatingcapacitance measurement by EIS:ideal and actualtrends[J].Electrochim Acta,1999,44:4243-4249.
[22]Castela AS,Simoes AM.An impedance model for theestimation of water absorption in organic coatings.PartII:A complex equation of mixture Castela[J].Corro-sion Science,2003,45:1647-1660.
[23]Allahar K N,Hinderliter B R,Bierwagen G P,et al.Cyclic wet drying of an epoxy coating using an ionicliquid[J].Progress in Organic Coatings.2008,62:87-95.
[24]Poelman M,Olivier M G,Gayarre N,et al.Electro-chemical study of different ageing tests for the evalua-tion of a cataphoretic epoxy primer on aluminium[J].Prog Org Coat,2005,54:55.
[25]Battocchi D,Simoes A M,Tallman D E,et al.Electro-chemical behaviour of a Mg-rich primerin the protec-tion of Al alloys[J].Corrosion Science,2006,48:1292-1306.
[26]Deflorian F,Rossia S,Fedrizzi L,et al.EIS study oforganic coating on zinc surface pretreated with envi-ronmentally friendly products[J].Prog Org Coat,2005,52:271-279.
[27]Tsuru T,Nishikata A,Wang J.Electrochemical studieson corrosion under a water film[J].Mater Sci Eng,1995,A198:161-168.
[28]Zhao Zeng-yuan(赵增元).Studies of the degradationof organic coatings using EIS and SKP[D].Qingdao:Ocean University of China,2007:46-47.



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