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Volumn 42, Issue 3, 2014, Pages 517-539

Electrochemical techniques in corrosion: Status, limitations, and needs

Author keywords

Corrosion; Electrochemical tests

Indexed keywords

CHEMICAL DETECTION; CORROSION; ELECTROCHEMICAL CORROSION; ELECTROCHEMISTRY;

EID: 84989833387     PISSN: 00903973     EISSN: None     Source Type: Journal    
DOI: 10.1520/JAI101241     Document Type: Article
Times cited : (18)

References (114)
  • 1
    • 84940495506 scopus 로고    scopus 로고
    • Experimental techniques for corrosion
    • M. Stratmann and G. S. Frankel, Eds., Wiley-VCH, Weinheim, Germany
    • Frankel, G. S. and Rohwerder, M., "Experimental Techniques for Corrosion," in Corrosion and Oxide Films, Encyclopedia of Electrochemistry, Vol. 4, M. Stratmann and G. S. Frankel, Eds., Wiley-VCH, Weinheim, Germany, 2003.
    • (2003) Corrosion and Oxide Films, Encyclopedia of Electrochemistry , vol.4
    • Frankel, G.S.1    Rohwerder, M.2
  • 2
    • 0000305710 scopus 로고
    • The polarization resistance technique for measuring corrosion currents
    • M. G. Fontana and R. W. Staehle, Eds., Plenum, New York
    • Mansfeld, F., "The Polarization Resistance Technique for Measuring Corrosion Currents," in Advances in Corrosion Science and Technology, M. G. Fontana and R. W. Staehle, Eds., Plenum, New York, 1976.
    • (1976) Advances in Corrosion Science and Technology
    • Mansfeld, F.1
  • 3
    • 84864983706 scopus 로고
    • Electrochemical methods for laboratory corrosion testing
    • Volume, R. Baboian and S. W. Dean, Eds., ASTM International, West Conshohocken, PA
    • Scully, J. R., "Electrochemical Methods for Laboratory Corrosion Testing," in Corrosion Testing and Evaluation: Silver Anniversary Volume, R. Baboian and S. W. Dean, Eds., ASTM International, West Conshohocken, PA, 1990.
    • (1990) Corrosion Testing and Evaluation: Silver Anniversary
    • Scully, J.R.1
  • 4
    • 0000040642 scopus 로고    scopus 로고
    • Polarization resistance method for determination of instantaneous corrosion rates
    • Scully, J. R., "Polarization Resistance Method for Determination of Instantaneous Corrosion Rates," Corrosion (Houston), Vol. 56, 2000, pp. 199-218.
    • (2000) Corrosion (Houston) , vol.56 , pp. 199-218
    • Scully, J.R.1
  • 6
    • 76649083517 scopus 로고
    • Corrosion aggressivity of atmospheres (Derivation and classification)
    • ASTM STP 767, S. W. Dean Jr. and E. C. Rhea, Eds., ASTM International, West Conshohocken, PA
    • Knotkova-Cermakova, D. and Barton, K., "Corrosion Aggressivity of Atmospheres (Derivation and Classification)," in Atmospheric Corrosion of Metals, ASTM STP 767, S. W. Dean Jr. and E. C. Rhea, Eds., ASTM International, West Conshohocken, PA, 1982.
    • (1982) Atmospheric Corrosion of Metals
    • Knotkova-Cermakova, D.1    Barton, K.2
  • 8
    • 76649145056 scopus 로고    scopus 로고
    • Standard practice for operating salt spray (Fog) testing apparatus
    • ASTM, Standard B117-97 ASTM International, West Conshohocken, PA
    • ASTM, Standard B117-97, "Standard Practice for Operating Salt Spray (Fog) Testing Apparatus," Annual Book of ASTM Standards, Vol. 3.02, ASTM International, West Conshohocken, PA, 2000.
    • (2000) Annual Book of ASTM Standards , vol.3 , Issue.2
  • 9
    • 0003866246 scopus 로고
    • Ed., ASTM STP ASTM International, West Conshohocken, PA
    • Cyclic Cabinet Corrosion Testing, G. S. Haynes, Ed., ASTM STP 1238, ASTM International, West Conshohocken, PA, 1995.
    • (1995) Cyclic Cabinet Corrosion Testing , pp. 1238
    • Haynes, G.S.1
  • 10
    • 76649099447 scopus 로고    scopus 로고
    • Corrosion in microelectronic and magnetic data-storage devices
    • 2nd Ed., P. Marcus, Ed., Marcel Dekker, New York
    • Frankel, G. S. and Braithwaite, J. W., "Corrosion in Microelectronic and Magnetic Data-Storage Devices," in Corrosion Mechanisms in Theory and Practice, 2nd Ed., P. Marcus, Ed., Marcel Dekker, New York, 2002.
    • (2002) Corrosion Mechanisms in Theory and Practice
    • Frankel, G.S.1    Braithwaite, J.W.2
  • 11
    • 0008822498 scopus 로고
    • Corrosion monitoring techniques Applied to cooling water and district heating systems
    • Paper 463 Houston, TX
    • Thierry, D., Thoren, A., and Leygraf, C., "Corrosion Monitoring Techniques Applied to Cooling Water and District Heating Systems," Paper 463, in Corrosion/87, NACE, Houston, TX, 1987.
    • (1987) Corrosion/87, NACE
    • Thierry, D.1    Thoren, A.2    Leygraf, C.3
  • 13
    • 76649088255 scopus 로고    scopus 로고
    • Wagner-traud to stern-geary; development of corrosion kinetics
    • G. S. Frankel, H. S. Isaacs, J. R. Scully, and J. D. Sinclair, Eds., The Electrochemical Society, New York
    • Frankel, G. S., "Wagner-Traud to Stern-Geary; Development of Corrosion Kinetics," in Corrosion Retrospective, G. S. Frankel, H. S. Isaacs, J. R. Scully, and J. D. Sinclair, Eds., The Electrochemical Society, New York, 2002.
    • (2002) Corrosion Retrospective
    • Frankel, G.S.1
  • 14
    • 34247094160 scopus 로고    scopus 로고
    • On the interpretation of corrosion processes through the superposition of electrochemical partial processes and on the potential of mixed electrodes
    • Wagner, C. and Traud, W., "On the Interpretation of Corrosion Processes Through the Superposition of Electrochemical Partial Processes and on the Potential of Mixed Electrodes," Corrosion, Vol. 62, 2006, pp. 844-855.
    • (2006) Corrosion , vol.62 , pp. 844-855
    • Wagner, C.1    Traud, W.2
  • 17
    • 0020846591 scopus 로고
    • Corrosion rates from impedance measurements: An improved approach for rapid automatic analysis
    • Kendig, M. and Mansfeld, F., "Corrosion Rates from Impedance Measurements: An Improved Approach for Rapid Automatic Analysis," Corrosion (Houston), Vol. 39, 1983, pp. 466-467.
    • (1983) Corrosion (Houston) , vol.39 , pp. 466-467
    • Kendig, M.1    Mansfeld, F.2
  • 18
    • 0019715248 scopus 로고
    • Determination of corrosion rates by electrochemical DC and AC methods
    • Lorenz, W. J. and Mansfeld, F., "Determination of Corrosion Rates by Electrochemical DC and AC Methods," Corros. Sci., Vol. 21, 1981, pp. 647-672.
    • (1981) Corros. Sci. , vol.21 , pp. 647-672
    • Lorenz, W.J.1    Mansfeld, F.2
  • 22
    • 0032141283 scopus 로고    scopus 로고
    • Analysis of electrochemical noise by power spectral density applied to corrosion studies. Maximum entropy method or fast fourier transform?
    • Bertocci, U., Frydman, J., Gabrielli, C., Huet, F., and Keddam, M., "Analysis of Electrochemical Noise by Power Spectral Density Applied to Corrosion Studies. Maximum Entropy Method or Fast Fourier Transform?," J. Electrochem. Soc., Vol. 145, 1998, pp. 2780-2786.
    • (1998) J. Electrochem. Soc. , vol.145 , pp. 2780-2786
    • Bertocci, U.1    Frydman, J.2    Gabrielli, C.3    Huet, F.4    Keddam, M.5
  • 23
    • 0030737845 scopus 로고    scopus 로고
    • Noise resistance applied to corrosion measurements. I. Theoretical analysis
    • Bertocci, U., Gabrielli, C., Huet, F., and Keddam, M., "Noise Resistance Applied to Corrosion Measurements. I. Theoretical Analysis," J. Electrochem. Soc., Vol. 144, 1997, pp. 31-37.
    • (1997) J. Electrochem. Soc. , vol.144 , pp. 31-37
    • Bertocci, U.1    Gabrielli, C.2    Huet, F.3    Keddam, M.4
  • 24
    • 0030784115 scopus 로고    scopus 로고
    • Noise resistance applied to corrosion measurements. II. Experimental tests
    • Bertocci, U., Gabrielli, C., Huet, F., Keddam, M., and Rousseau, P., "Noise Resistance Applied to Corrosion Measurements. II. Experimental Tests," J. Electrochem. Soc., Vol. 177, 1997, pp. 37-43.
    • (1997) J. Electrochem. Soc. , vol.177 , pp. 37-43
    • Bertocci, U.1    Gabrielli, C.2    Huet, F.3    Keddam, M.4    Rousseau, P.5
  • 25
    • 0031213385 scopus 로고    scopus 로고
    • Noise resistance applied to corrosion measurements. III. Influence of the instrumental noise on the measurements
    • Bertocci, U. and Huet, F., "Noise Resistance Applied to Corrosion Measurements. III. Influence of the Instrumental Noise on the Measurements," J. Electrochem. Soc., Vol. 144, 1997, pp. 2786-2793.
    • (1997) J. Electrochem. Soc. , vol.144 , pp. 2786-2793
    • Bertocci, U.1    Huet, F.2
  • 26
    • 0009992036 scopus 로고    scopus 로고
    • Interpretation of electrochemical noise data
    • Cottis, R. A., "Interpretation of Electrochemical Noise Data," Corrosion (Houston), Vol. 57, 2001, pp. 265-285.
    • (2001) Corrosion (Houston) , vol.57 , pp. 265-285
    • Cottis, R.A.1
  • 27
    • 0041490681 scopus 로고    scopus 로고
    • Listening to corrosion
    • Huet, F., "Listening to Corrosion," Interface (USA) 10, 2001, pp. 40-43.
    • (2001) Interface (USA) 10 , pp. 40-43
    • Huet, F.1
  • 28
    • 0027642418 scopus 로고
    • Electrochemical noise analysis of iron exposed to NaCl solutions of different corrosivity
    • Mansfeld, F. and Xiao, H., "Electrochemical Noise Analysis of Iron Exposed to NaCl Solutions of Different Corrosivity," J. Electrochem. Soc., Vol. 140, 1993, pp. 2205-2209.
    • (1993) J. Electrochem. Soc. , vol.140 , pp. 2205-2209
    • Mansfeld, F.1    Xiao, H.2
  • 29
    • 33646830313 scopus 로고    scopus 로고
    • Sources of electrochemical noise in corroding systems
    • Cottis, R. A., "Sources of Electrochemical Noise in Corroding Systems," Russ. J. Electrochem., Vol. 42, 2006, pp. 557-566.
    • (2006) Russ. J. Electrochem , vol.42 , pp. 557-566
    • Cottis, R.A.1
  • 31
    • 0344371399 scopus 로고    scopus 로고
    • Electrochemical frequency modulation: A new electrochemical technique for online corrosion monitoring
    • Bosch, R. W., Hubrecht, J., Bogaerts, W. F., Syrett, B. C., "Electrochemical Frequency Modulation: A New Electrochemical Technique for Online Corrosion Monitoring," Corrosion (Houston), Vol. 57, 2001, pp. 60-70.
    • (2001) Corrosion (Houston) , vol.57 , pp. 60-70
    • Bosch, R.W.1    Hubrecht, J.2    Bogaerts, W.F.3    Syrett, B.C.4
  • 32
    • 33645017307 scopus 로고    scopus 로고
    • An evaluation of the electrochemical frequency modulation (EFM) technique
    • Kus, E. and Mansfeld, F., "An Evaluation of the Electrochemical Frequency Modulation (EFM) Technique," Corros. Sci., Vol. 48, 2006, pp. 965-979.
    • (2006) Corros. Sci , vol.48 , pp. 965-979
    • Kus, E.1    Mansfeld, F.2
  • 33
    • 0029344396 scopus 로고
    • Micro- and nanotechniques to study localized corrosion
    • Bohni, H., Suter, T., and Schreyer, A., "Micro- and Nanotechniques to Study Localized Corrosion," Electrochim. Acta, Vol. 40, 1995, pp. 1361-1368.
    • (1995) Electrochim. Acta , vol.40 , pp. 1361-1368
    • Bohni, H.1    Suter, T.2    Schreyer, A.3
  • 34
    • 0035127057 scopus 로고    scopus 로고
    • Microelectrochemical studies of pit initiation at single inclusions in Al 2024-T3
    • Suter, T. and Alkire, R. C., "Microelectrochemical Studies of Pit Initiation at Single Inclusions in Al 2024-T3," J. Electrochem. Soc., Vol. 148, 2001, pp. B36-B42.
    • (2001) J. Electrochem. Soc , vol.148 , pp. B36-B42
    • Suter, T.1    Alkire, R.C.2
  • 35
    • 0035451576 scopus 로고    scopus 로고
    • Microelectrodes for corrosion studies in microsystems
    • Suter, T. and Bohni, H., "Microelectrodes for Corrosion Studies in Microsystems," Electrochim. Acta, Vol. 47, 2001, pp. 191-199.
    • (2001) Electrochim. Acta , vol.47 , pp. 191-199
    • Suter, T.1    Bohni, H.2
  • 36
    • 0029501206 scopus 로고
    • Microelectrochemical investigations of MnS inclusions
    • Suter, T., Peter, T., and Bohni, H., "Microelectrochemical Investigations of MnS Inclusions," Mater. Sci. Forum, 1995, pp. 25-40.
    • (1995) Mater. Sci. Forum , pp. 25-40
    • Suter, T.1    Peter, T.2    Bohni, H.3
  • 40
    • 0002630833 scopus 로고
    • Ellipsometric-potentiostatic studies of iron passivity
    • Kruger, J. and Calvert, J. P., "Ellipsometric-Potentiostatic Studies of Iron Passivity," J. Electrochem. Soc., Vol. 114, 1967, pp. 43-49.
    • (1967) J. Electrochem. Soc , vol.114 , pp. 43-49
    • Kruger, J.1    Calvert, J.P.2
  • 41
    • 0016922338 scopus 로고
    • Anodic oxide films on nickel in acid solutions
    • MacDougall, B. and Cohen, M., "Anodic Oxide Films on Nickel in Acid Solutions," J. Electro-chem. Soc., Vol. 123, 1976, pp. 191-197.
    • (1976) J. Electro-chem. Soc , vol.123 , pp. 191-197
    • MacDougall, B.1    Cohen, M.2
  • 42
    • 84975362910 scopus 로고
    • The kinetics of anodic oxidation of iron in neutral solution
    • Sato, N. and Cohen, M., "The Kinetics of Anodic Oxidation of Iron in Neutral Solution," J. Electrochem. Soc., Vol. 111, 1964, pp. 512-519.
    • (1964) J. Electrochem. Soc , vol.111 , pp. 512-519
    • Sato, N.1    Cohen, M.2
  • 43
    • 0020497153 scopus 로고
    • Growth of passivating films on scratched 304L stainless steel in alkaline solution
    • Burstein, G. T. and Marshall, P. I., "Growth of Passivating Films on Scratched 304L Stainless Steel in Alkaline Solution," Corros. Sci., Vol. 23, 1983, pp. 125-137.
    • (1983) Corros. Sci , vol.23 , pp. 125-137
    • Burstein, G.T.1    Marshall, P.I.2
  • 44
    • 0019053423 scopus 로고
    • Anodic behaviour of scratched silver electrodes in alkaline solution
    • Burstein, G. T. and Newman, R. C., "Anodic Behaviour of Scratched Silver Electrodes in Alkaline Solution," Electrochim. Acta, Vol. 25, 1980, pp. 1009-1013.
    • (1980) Electrochim. Acta , vol.25 , pp. 1009-1013
    • Burstein, G.T.1    Newman, R.C.2
  • 45
    • 0019282390 scopus 로고
    • Analysis of anodic films formed on cobalt in bicarbonate and borate electrolytes
    • Burstein, G. T. and Davies, D. H., "Analysis of Anodic Films Formed on Cobalt in Bicarbonate and Borate Electrolytes," Corros. Sci., Vol. 20, 1980, pp. 989-995.
    • (1980) Corros. Sci , vol.20 , pp. 989-995
    • Burstein, G.T.1    Davies, D.H.2
  • 46
    • 0023960450 scopus 로고
    • Use of 18O/SIMS and electrochemical techniques to study the reduction and breakdown of passive oxide films on iron
    • Bardwell, J. A., MacDougall, B., and Graham, M. J., "Use of 18O/SIMS and Electrochemical Techniques to Study the Reduction and Breakdown of Passive Oxide Films on Iron," J. Electro-chem. Soc., Vol. 135, 1988, pp. 413-418.
    • (1988) J. Electro-chem. Soc , vol.135 , pp. 413-418
    • Bardwell, J.A.1    MacDougall, B.2    Graham, M.J.3
  • 47
    • 0024639579 scopus 로고
    • The current-time relationship during anodic oxide film growth under high electric field
    • Burstein, G. T. and Davenport, A. J., "The Current-Time Relationship During Anodic Oxide Film Growth Under High Electric Field," J. Electrochem. Soc., Vol. 136, 1989, pp. 936-941.
    • (1989) J. Electrochem. Soc , vol.136 , pp. 936-941
    • Burstein, G.T.1    Davenport, A.J.2
  • 48
    • 0025243894 scopus 로고
    • Confirmation of the applicability of scratched electrode techniques for the determination of bare surface current densitites
    • Kelly, R. G. and Newman, R. C., "Confirmation of the Applicability of Scratched Electrode Techniques for the Determination of Bare Surface Current Densitites," J. Electrochem. Soc., Vol. 137, 1990, pp. 357-358.
    • (1990) J. Electrochem. Soc , vol.137 , pp. 357-358
    • Kelly, R.G.1    Newman, R.C.2
  • 49
    • 0029342978 scopus 로고
    • Repassivation transients measured with the breaking-electrode technique on aluminum thin-film samples
    • Frankel, G. S., and Jahnes., C. V., Brusic, V., and Davenport, A. J., "Repassivation Transients Measured with the Breaking-Electrode Technique on Aluminum Thin-Film Samples," J. Electrochem. Soc., Vol. 142, 1995, pp. 2290-2295.
    • (1995) J. Electrochem. Soc , vol.142 , pp. 2290-2295
    • Frankel, G.S.1    Jahnes, C.V.2    Brusic, V.3    Davenport, A.J.4
  • 50
    • 0032096642 scopus 로고    scopus 로고
    • Pitting corrosion of metals: A review of the critical factors
    • Frankel, G. S., "Pitting Corrosion of Metals: A Review of the Critical Factors," J. Electrochem. Soc., Vol. 145, 1998, pp. 2186-2197.
    • (1998) J. Electrochem. Soc , vol.145 , pp. 2186-2197
    • Frankel, G.S.1
  • 51
    • 0001369723 scopus 로고
    • Determination of critical pitting potentials of stainless steel in aquious chloride environments
    • Pessall, N. and Liu, C., "Determination of Critical Pitting Potentials of Stainless Steel in Aquious Chloride Environments," Electrochim. Acta, Vol. 16, 1971, pp. 1987-2003.
    • (1971) Electrochim. Acta , vol.16 , pp. 1987-2003
    • Pessall, N.1    Liu, C.2
  • 52
    • 76649102655 scopus 로고    scopus 로고
    • Standard test method for pitting or crevice corrosion of metallic surgical implant materials
    • ASTM Standard F746-87 ASTM International, West Conshohocken, PA
    • ASTM Standard F746-87, "Standard Test Method for Pitting or Crevice Corrosion of Metallic Surgical Implant Materials," Annual Book of ASTM Standards, Vol. 13.01, ASTM International, West Conshohocken, PA, 2000.
    • (2000) Annual Book of ASTM Standards , vol.13 , Issue.1
  • 53
    • 0032123781 scopus 로고    scopus 로고
    • Characterization of AA2024-T3 by scanning kelvin probe force microscopy
    • Schmutz, P. and Frankel, G. S., "Characterization of AA2024-T3 by Scanning Kelvin Probe Force Microscopy," J. Electrochem. Soc., Vol. 145, 1998, pp. 2285-2294.
    • (1998) J. Electrochem. Soc , vol.145 , pp. 2285-2294
    • Schmutz, P.1    Frankel, G.S.2
  • 54
    • 0032123764 scopus 로고    scopus 로고
    • Corrosion study of AA2024-T3 by scanning kelvin probe force microscopy and in situ AFM scratching
    • Schmutz, P. and Frankel, G. S., "Corrosion Study of AA2024-T3 by Scanning Kelvin Probe Force Microscopy and In Situ AFM Scratching," J. Electrochem. Soc., Vol. 145, 1998, pp. 2298-2306.
    • (1998) J. Electrochem. Soc , vol.145 , pp. 2298-2306
    • Schmutz, P.1    Frankel, G.S.2
  • 55
    • 76649141977 scopus 로고    scopus 로고
    • Studies of corrosion using scanning kelvin probe force microscopy and AFM scratching
    • Frankel, G. S. and Leblanc, P., "Studies of Corrosion Using Scanning Kelvin Probe Force Microscopy and AFM Scratching," Corros. Sci. Technol., Vol. 31, 2002, pp. 419-425.
    • (2002) Corros. Sci. Technol , vol.31 , pp. 419-425
    • Frankel, G.S.1    Leblanc, P.2
  • 56
    • 44349114485 scopus 로고    scopus 로고
    • Inhibition of AA2024-T3 corrosion by vanadates: An AFM scratching investigation
    • Iannuzzi, M. and Frankel, G. S., "Inhibition of AA2024-T3 Corrosion by Vanadates: An AFM Scratching Investigation," Corrosion (Houston), Vol. 63, 2007, pp. 672-688.
    • (2007) Corrosion (Houston) , vol.63 , pp. 672-688
    • Iannuzzi, M.1    Frankel, G.S.2
  • 57
    • 0001526766 scopus 로고    scopus 로고
    • Influence of dichromate ions on corrosion of pure aluminum and AA2024-T3 in NaCl solution studied by AFM scratching
    • Schmutz, P. and Frankel, G. S., "Influence of Dichromate Ions on Corrosion of Pure Aluminum and AA2024-T3 in NaCl Solution Studied by AFM Scratching," J. Electrochem. Soc., Vol. 146, 1999, pp. 4461-4472.
    • (1999) J. Electrochem. Soc , vol.146 , pp. 4461-4472
    • Schmutz, P.1    Frankel, G.S.2
  • 59
    • 76649137168 scopus 로고    scopus 로고
    • Development in the concept of repassivation potential as a measure of crevice corrosion susceptibility
    • F. M. G. Wong and J. H. Payer, Eds., Dept. of Energy, Washington, DC
    • Shibata, T., "Development in the Concept of Repassivation Potential as a Measure of Crevice Corrosion Susceptibility," in A Compilation of Special Topic Reports, F. M. G. Wong and J. H. Payer, Eds., Dept. of Energy, Washington, DC, 2002, http://www.ocrwm.doe.gov/documents/peer-2/index.pdf.
    • (2002) A Compilation of Special Topic Reports
    • Shibata, T.1
  • 60
    • 14344249747 scopus 로고    scopus 로고
    • Using electrochemical methods to determine alloy 22's crevice corrosion repassivation potential
    • Evans, K. J., Yilmaz, A., Day, S. D.I, Wong, L. L., and Estill., J. C., Rebak, R. B., "Using Electrochemical Methods to Determine Alloy 22's Crevice Corrosion Repassivation Potential," JOM, Vol. 57, 2005, pp. 56-61.
    • (2005) JOM , vol.57 , pp. 56-61
    • Evans, K.J.1    Yilmaz, A.2    Day, S.D.I.3    Wong, L.L.4    Estill, J.C.5    Rebak, R.B.6
  • 61
    • 76649106009 scopus 로고    scopus 로고
    • Standard guide for crevice corrosion testing of iron-base and nickel-base stainless alloys in seawater and other chloride-containing aqueous environments
    • ASTM Standard G79-01 ASTM International, West Conshohocken, PA
    • ASTM Standard G79-01, "Standard Guide for Crevice Corrosion Testing of Iron-Base and Nickel-Base Stainless Alloys in Seawater and Other Chloride-Containing Aqueous Environments," Annual Book of ASTM Standards, Vol. 3.02, ASTM International, West Conshohocken, PA, 2004.
    • (2004) Annual Book of ASTM Standards , vol.3 , Issue.2
  • 63
    • 0033318162 scopus 로고    scopus 로고
    • The influence of dichromate ions on al dissolution kinetics in artificial crevice electrode cells
    • Akiyama, E. and Frankel, G. S., "The Influence of Dichromate Ions on Al Dissolution Kinetics in Artificial Crevice Electrode Cells," J. Electrochem. Soc., Vol. 146, 1999, pp. 4095-4100.
    • (1999) J. Electrochem. Soc , vol.146 , pp. 4095-4100
    • Akiyama, E.1    Frankel, G.S.2
  • 64
    • 0025627101 scopus 로고
    • The growth of 2-D pits in thin film aluminum
    • Frankel, G. S., "The Growth of 2-D Pits in Thin Film Aluminum," Corros. Sci., Vol. 30, 1990, pp. 1203-1218.
    • (1990) Corros. Sci , vol.30 , pp. 1203-1218
    • Frankel, G.S.1
  • 65
    • 0016571101 scopus 로고
    • Diffusional effects in simulated localized corrosion
    • Tester, J. W. and Isaacs, H. S., "Diffusional Effects in Simulated Localized Corrosion," J. Electro-chem. Soc., Vol. 122, 1975, pp. 1438-1445.
    • (1975) J. Electro-chem. Soc , vol.122 , pp. 1438-1445
    • Tester, J.W.1    Isaacs, H.S.2
  • 66
    • 0022732053 scopus 로고
    • Mass transfer and electrochemical kinetic interactions in localized pitting corrosion
    • Gaudet, G. T., and Mo., W. T., Hatton, T. A., Tester, J. W., Tilly, J., and Isaacs., H. S., Newman, R. C., "Mass Transfer and Electrochemical Kinetic Interactions in Localized Pitting Corrosion," AIChE J., Vol. 32, 1986, pp. 949-958.
    • (1986) AIChE J , vol.32 , pp. 949-958
    • Gaudet, G.T.1    Mo, W.T.2    Hatton, T.A.3    Tester, J.W.4    Tilly, J.5    Isaacs, H.S.6    Newman, R.C.7
  • 67
    • 76649122108 scopus 로고
    • Dissolution kinetics during localized corrosion
    • R. P. Frankenthal and F. Mansfeld, Eds., ECS, Pennington, NJ
    • Isaacs, H. S. and Newman, R. C., "Dissolution Kinetics During Localized Corrosion," in Corrosion and Corrosion Protection, R. P. Frankenthal and F. Mansfeld, Eds., ECS, Pennington, NJ, 1981.
    • (1981) Corrosion and Corrosion Protection
    • Isaacs, H.S.1    Newman, R.C.2
  • 68
    • 0021831431 scopus 로고
    • The dissolution and passivation kinetics of stainless alloys containing molybdenum - I. Coulometric studies of Fe-Cr and Fe-Cr-Mo alloys
    • Newman, R. C., "The Dissolution and Passivation Kinetics of Stainless Alloys Containing Molybdenum - I. Coulometric Studies of Fe-Cr and Fe-Cr-Mo Alloys," Corros. Sci., Vol. 25, 1985, pp. 331-339.
    • (1985) Corros. Sci , vol.25 , pp. 331-339
    • Newman, R.C.1
  • 69
    • 0021820910 scopus 로고
    • The dissolution and passivation kinetics of stainless alloys containing molybdenum-II. Dissolution kinetics in artificial pits
    • Newman, R. C., "The Dissolution and Passivation Kinetics of Stainless Alloys Containing Molybdenum-II. Dissolution Kinetics in Artificial Pits," Corros. Sci., Vol. 25, 1985, pp. 341-350.
    • (1985) Corros. Sci , vol.25 , pp. 341-350
    • Newman, R.C.1
  • 70
    • 0033727080 scopus 로고    scopus 로고
    • Anisotropy of localized corrosion in AA2024-T3
    • Zhang, W. and Frankel, G. S., "Anisotropy of Localized Corrosion in AA2024-T3," Electrochem. Solid-State Lett., Vol. 3, 2000, pp. 268-270.
    • (2000) Electrochem. Solid-State Lett , vol.3 , pp. 268-270
    • Zhang, W.1    Frankel, G.S.2
  • 71
    • 0033896078 scopus 로고    scopus 로고
    • Pit growth study in al alloys by the foil penetration technique
    • Sehgal, A., and Frankel., G. S., Zoofan, B., and Rokhlin, S., "Pit Growth Study in Al Alloys by the Foil Penetration Technique," J. Electrochem. Soc., Vol. 147, 2000, pp. 140-148.
    • (2000) J. Electrochem. Soc , vol.147 , pp. 140-148
    • Sehgal, A.1    Frankel, G.S.2    Zoofan, B.3    Rokhlin, S.4
  • 72
    • 0019634925 scopus 로고
    • Determination of pit growth rates on aluminum using a metal foil technique
    • Hunkeler, F. and Bohni, H., "Determination of Pit Growth Rates on Aluminum Using a Metal Foil Technique," Corros. Sci., Vol. 37, 1981, pp. 645-650.
    • (1981) Corros. Sci , vol.37 , pp. 645-650
    • Hunkeler, F.1    Bohni, H.2
  • 73
    • 0030173325 scopus 로고    scopus 로고
    • Repassivation of pits in aluminum thin films
    • Frankel, G. S., and Scully., J. R., Jahnes, C. V., "Repassivation of Pits in Aluminum Thin Films," J. Electrochem. Soc., Vol. 143, 1996, pp. 1834-1840.
    • (1996) J. Electrochem. Soc , vol.143 , pp. 1834-1840
    • Frankel, G.S.1    Scully, J.R.2    Jahnes, C.V.3
  • 75
    • 0032141280 scopus 로고    scopus 로고
    • Pitting in aluminum thin films: Supersaturation and effects of dichromate ions
    • Sehgal, A., Lu, D., and Frankel, G. S., "Pitting in Aluminum Thin Films: Supersaturation and Effects of Dichromate Ions," J. Electrochem. Soc., Vol. 145, 1998, pp. 2834-2840.
    • (1998) J. Electrochem. Soc , vol.145 , pp. 2834-2840
    • Sehgal, A.1    Lu, D.2    Frankel, G.S.3
  • 76
    • 0024719227 scopus 로고
    • A fitting procedure for impedance sectra obtained for cases of localized corrosion
    • Shih, H. and Mansfeld, F., "A Fitting Procedure for Impedance Sectra Obtained for Cases of Localized Corrosion," Corrosion (Houston), Vol. 45, 1989, pp. 610-614.
    • (1989) Corrosion (Houston) , vol.45 , pp. 610-614
    • Shih, H.1    Mansfeld, F.2
  • 77
    • 0024302207 scopus 로고
    • Corrosion of thin film magnetic disk: Galvanic effects of the carbon overcoat
    • Brusic, V., Russak, M., Schad, R., Frankel, G., Selius, A., and DiMilia, D., "Corrosion of Thin Film Magnetic Disk: Galvanic Effects of the Carbon Overcoat," J. Electrochem. Soc., Vol. 136, 1989, pp. 42-46.
    • (1989) J. Electrochem. Soc , vol.136 , pp. 42-46
    • Brusic, V.1    Russak, M.2    Schad, R.3    Frankel, G.4    Selius, A.5    DiMilia, D.6
  • 78
    • 0016890998 scopus 로고
    • Electrochemical monitoring of atmospheric corrosion phenomena
    • Mansfeld, F. and Kenkel, J. V., "Electrochemical Monitoring of Atmospheric Corrosion Phenomena," Corros. Sci., Vol. 16, 1976, pp. 111-122.
    • (1976) Corros. Sci , vol.16 , pp. 111-122
    • Mansfeld, F.1    Kenkel, J.V.2
  • 79
    • 0024030471 scopus 로고
    • Monitoring of atmospheric corrosion phenomena with electrochemical sensors
    • Mansfeld, F., "Monitoring of Atmospheric Corrosion Phenomena with Electrochemical Sensors," J. Electrochem. Soc., Vol. 135, 1988, pp. 1354-1358.
    • (1988) J. Electrochem. Soc , vol.135 , pp. 1354-1358
    • Mansfeld, F.1
  • 80
    • 0028468959 scopus 로고
    • Electrochemical study of the atmospheric corrosion of mild steel-I. Experimental method
    • Cox, A. and Lyon, S. B., "Electrochemical Study of the Atmospheric Corrosion of Mild Steel-I. Experimental Method," Corros. Sci., Vol. 36, 1994, pp. 1167-1176.
    • (1994) Corros. Sci , vol.36 , pp. 1167-1176
    • Cox, A.1    Lyon, S.B.2
  • 81
    • 0028468960 scopus 로고
    • Electrochemical study of the atmospheric corrosion of mild steel-III. The effect of sulphur dioxide
    • Cox, A. and Lyon, S. B., "Electrochemical Study of the Atmospheric Corrosion of Mild Steel-III. The Effect of Sulphur Dioxide," Corros. Sci., Vol. 36, 1994, pp. 1193-1199.
    • (1994) Corros. Sci , vol.36 , pp. 1193-1199
    • Cox, A.1    Lyon, S.B.2
  • 82
    • 0028468961 scopus 로고
    • Electrochemical study of the atmospheric corrosion of iron-II. Cathodic and anodic processes on uncorroded and pre-corroded
    • Cox, A. and Lyon, S. B., "Electrochemical Study of the Atmospheric Corrosion of Iron-II. Cathodic and Anodic Processes on Uncorroded and Pre-Corroded," Corros. Sci., Vol. 36, 1994, pp. 1177-1192.
    • (1994) Corros. Sci , vol.36 , pp. 1177-1192
    • Cox, A.1    Lyon, S.B.2
  • 83
    • 0028486318 scopus 로고
    • Anodic processes on iron covered by thin, dilute electrolyte layers (I)-anodic polarization
    • Zhang, S. H. and Lyon, S. B., "Anodic Processes on Iron Covered by Thin, Dilute Electrolyte Layers (I)-Anodic Polarization," Corros. Sci., Vol. 36, 1994, pp. 1289-1307.
    • (1994) Corros. Sci , vol.36 , pp. 1289-1307
    • Zhang, S.H.1    Lyon, S.B.2
  • 84
    • 0028486322 scopus 로고
    • Anodic processes on iron covered by thin, dilute electrolyte layers (II) - A.c. Impedance measurements
    • Zhang, S. H. and Lyon, S. B., "Anodic Processes on Iron Covered by Thin, Dilute Electrolyte Layers (II)-a.c. Impedance Measurements," Corros. Sci., Vol. 36, 1994, pp. 1309-1321.
    • (1994) Corros. Sci , vol.36 , pp. 1309-1321
    • Zhang, S.H.1    Lyon, S.B.2
  • 85
    • 0025192732 scopus 로고
    • On the atmospheric corrosion of metals, which are covered with thin electrolyte layers Part 1: Verification of the experimental technique
    • Stratmann, M. and Streckel, H., "On the Atmospheric Corrosion of Metals, Which are Covered with Thin Electrolyte Layers Part 1: Verification of the Experimental Technique," Corros. Sci., Vol. 30, 1990, pp. 681-696.
    • (1990) Corros. Sci , vol.30 , pp. 681-696
    • Stratmann, M.1    Streckel, H.2
  • 86
    • 0025192734 scopus 로고
    • On the atmospheric corrosion of metals, which are covered with thin electrolyte layers Part 2: Experimental results
    • Stratmann, M. and Streckel, H., "On the Atmospheric Corrosion of Metals, Which are Covered with Thin Electrolyte Layers Part 2: Experimental Results," Corros. Sci., Vol. 30, 1990, pp. 697-714.
    • (1990) Corros. Sci , vol.30 , pp. 697-714
    • Stratmann, M.1    Streckel, H.2
  • 87
    • 0025192736 scopus 로고
    • On the atmospheric corrosion of metals, which are covered with thin electrolyte layers Part 3: The measurement of polarization curves on metal surfaces which are covered by thin electrolyte layers
    • Stratmann, M., Streckel, H., Kim, K. T., and Crockett, S., "On the Atmospheric Corrosion of Metals, Which are Covered with Thin Electrolyte Layers Part 3: The Measurement of Polarization Curves on Metal Surfaces Which are Covered by Thin Electrolyte Layers," Corros. Sci., Vol. 90, 1990, pp. 715-734.
    • (1990) Corros. Sci , vol.90 , pp. 715-734
    • Stratmann, M.1    Streckel, H.2    Kim, K.T.3    Crockett, S.4
  • 89
    • 0031117719 scopus 로고    scopus 로고
    • Influence of electrolyte layer thickness and pH on the initial stage of the atmosphere corrosion of iron
    • Nishikata, A., Ishihara, Y., Hayashi, Y., and Tsuru, T., "Influence of Electrolyte Layer Thickness and pH on the Initial Stage of the Atmosphere Corrosion of Iron," J. Electrochem. Soc., Vol. 144, 1997, pp. 1244-1252.
    • (1997) J. Electrochem. Soc , vol.144 , pp. 1244-1252
    • Nishikata, A.1    Ishihara, Y.2    Hayashi, Y.3    Tsuru, T.4
  • 90
    • 0029138377 scopus 로고
    • An application of electrochemical impedance spectroscopy to atmospheric corrosion study
    • Nishikata, A., Ishihara, Y., and Tsuru, T., "An Application of Electrochemical Impedance Spectroscopy to Atmospheric Corrosion Study," Corros. Sci., Vol. 37, 1995, pp. 897-911.
    • (1995) Corros. Sci , vol.37 , pp. 897-911
    • Nishikata, A.1    Ishihara, Y.2    Tsuru, T.3
  • 91
    • 0029516647 scopus 로고
    • An electrochemical impedance study on atmospheric corrosion of steels in a cyclic wet-dry condition
    • Nishikata, A., Yamashita, Y., Katayama, H., Tsuru, T., Usami, A., Tanabe, K., and Mabuchi, H., "An Electrochemical Impedance Study on Atmospheric Corrosion of Steels in a Cyclic Wet-Dry Condition," Corros. Sci., Vol. 37, 1995, pp. 2059-2069.
    • (1995) Corros. Sci , vol.37 , pp. 2059-2069
    • Nishikata, A.1    Yamashita, Y.2    Katayama, H.3    Tsuru, T.4    Usami, A.5    Tanabe, K.6    Mabuchi, H.7
  • 92
    • 0030208748 scopus 로고    scopus 로고
    • AC impedance monitoring of pitting corrosion of stainless steel under a wet-dry cyclic condition in ChlorideContaining environment
    • Vera Cruz, R. P., Nishikata, A., and Tsuru, T., "AC Impedance Monitoring of Pitting Corrosion of Stainless Steel Under a Wet-Dry Cyclic Condition in ChlorideContaining Environment," Corros. Sci., Vol. 38, 1996, pp. 1397-1406.
    • (1996) Corros. Sci , vol.38 , pp. 1397-1406
    • Vera Cruz, R.P.1    Nishikata, A.2    Tsuru, T.3
  • 93
    • 0004644983 scopus 로고    scopus 로고
    • Pitting corrosion mechanism of stainless steels under wet-dry exposure in chloride-containing environments
    • Vera Cruz, R. P., Nishikata, A., and Tsuru, T., "Pitting Corrosion Mechanism of Stainless Steels Under Wet-Dry Exposure in Chloride-Containing Environments," Corros. Sci., Vol. 40, 1998, pp. 125-139.
    • (1998) Corros. Sci , vol.40 , pp. 125-139
    • Vera Cruz, R.P.1    Nishikata, A.2    Tsuru, T.3
  • 94
    • 25644441635 scopus 로고    scopus 로고
    • Anodic behavior of iron in acid solutions
    • Tsutsumi, Y., Nishikata, A., and Tsuru, T., "Anodic Behavior of Iron in Acid Solutions," J. Elec-trochem. Soc., Vol. 152, 2005, pp. B358-B363.
    • (2005) J. Elec-trochem. Soc , vol.152 , pp. B358-B363
    • Tsutsumi, Y.1    Nishikata, A.2    Tsuru, T.3
  • 95
    • 84859980393 scopus 로고    scopus 로고
    • Standard test method for exfoliation corrosion susceptibility in 2xxx and 7xxx series aluminum alloys(EXCO test)
    • ASTM, Standard G34-01 ASTM International, West Conshohocken, PA
    • ASTM, Standard G34-01, "Standard Test Method for Exfoliation Corrosion Susceptibility in 2xxx and 7xxx Series Aluminum Alloys(EXCO Test)," Annual Book of ASTM Standards, ASTM International, West Conshohocken, PA, 2004.
    • (2004) Annual Book of ASTM Standards
  • 96
    • 76649118711 scopus 로고
    • Modification of the EXCO test method for exfoliation corrosion susceptibility in 7XXX, 2XXX and aluminum-lithium alloys
    • ASTM STP 1134, V. S. Agarwala and G. M. Ugiansky, Eds., ASTM International, West Conshohocken, PA
    • Lee, S. and Lifka, B. W., "Modification of the EXCO Test Method for Exfoliation Corrosion Susceptibility in 7XXX, 2XXX and Aluminum-Lithium Alloys," in New Methods for Corrosion Testing of Aluminum Alloys, ASTM STP 1134, V. S. Agarwala and G. M. Ugiansky, Eds., ASTM International, West Conshohocken, PA, 1992.
    • (1992) New Methods for Corrosion Testing of Aluminum Alloys
    • Lee, S.1    Lifka, B.W.2
  • 98
    • 0003992108 scopus 로고
    • Modified salt spray (Fog) testing, laboratory corrosion tests and standards
    • STP 866, ASTM International, West Conshohocken, PA
    • Haynes, G. S. and Baboian, R., "Modified Salt Spray (Fog) Testing, Laboratory Corrosion Tests and Standards," in ASTM Standard G85-85 A2, STP 866, ASTM International, West Conshohocken, PA, 1985.
    • (1985) ASTM Standard G85-85 A2
    • Haynes, G.S.1    Baboian, R.2
  • 99
    • 0345650586 scopus 로고
    • An improved exfoliation test for aluminum alloys
    • Lifka, B. W. and Sprowls, D. O., "An Improved Exfoliation Test for Aluminum Alloys," Corrosion (Houston), Vol. 22, 1966, pp. 7-15.
    • (1966) Corrosion (Houston) , vol.22 , pp. 7-15
    • Lifka, B.W.1    Sprowls, D.O.2
  • 100
    • 0010676087 scopus 로고
    • Simplified exfoliation testing of aluminum alloys
    • ASTM STP 516, ASTM International, West Conshohocken, PA
    • Sprowls, D. O., and Walsh., J. D., Shumaker, M. B., "Simplified Exfoliation Testing of Aluminum Alloys," in Localized Corrosion-Cause of Metal Failure, ASTM STP 516, ASTM International, West Conshohocken, PA, 1972.
    • (1972) Localized Corrosion-Cause of Metal Failure
    • Sprowls, D.O.1    Walsh, J.D.2    Shumaker, M.B.3
  • 101
    • 0029509298 scopus 로고
    • Exfoliation corrosion testing of aluminum alloys
    • Braun, R., "Exfoliation Corrosion Testing of Aluminum Alloys," Br. Corros. J., London, Vol. 30, 1995, pp. 203-208.
    • (1995) Br. Corros. J., London , vol.30 , pp. 203-208
    • Braun, R.1
  • 102
    • 76649116466 scopus 로고
    • Relationship of accelerated test methods for exfoliation resistance in 7xxx series aluminum alloys with exposure to a seacoast atmosphere
    • ASTM International, West Conshohocken, PA
    • Lifka, B. W. and Sprowls, D. O., "Relationship of Accelerated Test Methods for Exfoliation Resistance in 7xxx Series Aluminum Alloys with Exposure to a Seacoast Atmosphere," in ASTM Special Technical Publication 558, ASTM International, West Conshohocken, PA, 1973.
    • (1973) ASTM Special Technical Publication 558
    • Lifka, B.W.1    Sprowls, D.O.2
  • 103
    • 84989821200 scopus 로고
    • Exfoliation corrosion testing of 7075 and 7178 aluminum alloys-interim report on atmospheric exposure tests
    • West Conshohocken, PA
    • Sprowls, D. O., and Summerson., T. J., Loftin, F. E., "Exfoliation Corrosion Testing of 7075 and 7178 Aluminum Alloys-Interim Report on Atmospheric Exposure Tests," ASTM International, West Conshohocken, PA, 1973.
    • (1973) ASTM International
    • Sprowls, D.O.1    Summerson, T.J.2    Loftin, F.E.3
  • 104
    • 0344127707 scopus 로고
    • The exfoliation corrosion of aluminum alloys
    • Liddiard, E. A. G., and Whittaker., J. A., Farmery, H. K., "The Exfoliation Corrosion of Aluminum Alloys," J. Inst. Met., Vol. 89, 1960-1961, pp. 377-384.
    • (1960) J. Inst. Met , vol.89 , pp. 377-384
    • Liddiard, E.A.G.1    Whittaker, J.A.2    Farmery, H.K.3
  • 105
    • 76649089563 scopus 로고    scopus 로고
    • Effects of RH, temper and stress on exfoliation corrosion kinetics of AA7178
    • Zhao, X. and Frankel, G. S., "Effects of RH, Temper and Stress on Exfoliation Corrosion Kinetics of AA7178," Corrosion (Houston), Vol. 62, 2006, pp. 256-266.
    • (2006) Corrosion (Houston) , vol.62 , pp. 256-266
    • Zhao, X.1    Frankel, G.S.2
  • 106
    • 33751439042 scopus 로고    scopus 로고
    • Quantitative study of exfoliation corrosion: Exfoliation of slices in humidity technique
    • Zhao, X. and Frankel, G. S., "Quantitative Study of Exfoliation Corrosion: Exfoliation of Slices in Humidity Technique," Corros. Sci., Vol. 49, 2007, pp. 920-938.
    • (2007) Corros. Sci , vol.49 , pp. 920-938
    • Zhao, X.1    Frankel, G.S.2
  • 109
    • 28444448785 scopus 로고    scopus 로고
    • Potentiostatic pulse testing for assessment of early coating failure
    • Kang, J. and Frankel, G. S., "Potentiostatic Pulse Testing for Assessment of Early Coating Failure," Z. Phys. Chem., Vol. 219, 2005, pp. 1519-1538.
    • (2005) Z. Phys. Chem , vol.219 , pp. 1519-1538
    • Kang, J.1    Frankel, G.S.2
  • 111
    • 33645133610 scopus 로고    scopus 로고
    • 2005 W. R. Whitney award lecture: Corrosion stability of polymer-coated metals-new concepts based on fundamental understanding
    • Stratmann, M., "2005 W. R. Whitney Award Lecture: Corrosion Stability of Polymer-Coated Metals-New Concepts Based on Fundamental Understanding," Corrosion (Houston), Vol. 661, 2005, pp. 1115-1126.
    • (2005) Corrosion (Houston) , vol.661 , pp. 1115-1126
    • Stratmann, M.1
  • 112
    • 0032122646 scopus 로고    scopus 로고
    • Corrosion protection of untreated AA2024-T3 in chloride solution by chromate conversion coating monitored with Raman spectroscopy
    • Zhao, J., and Frankel., G. S., McCreery, R. L., "Corrosion Protection of Untreated AA2024-T3 in Chloride Solution by Chromate Conversion Coating Monitored with Raman Spectroscopy," J. Electrochem. Soc., Vol. 145, 1998, pp. 2258-2264.
    • (1998) J. Electrochem. Soc , vol.145 , pp. 2258-2264
    • Zhao, J.1    Frankel, G.S.2    McCreery, R.L.3
  • 113
    • 0036162881 scopus 로고    scopus 로고
    • Active corrosion protection in Ce-modified hydrotalcite conversion coatings
    • Buchheit, R. G., and Mamidipally., S. B., Schmutz, P., and Guan, H., "Active Corrosion Protection in Ce-Modified Hydrotalcite Conversion Coatings," Corrosion (Houston), Vol. 58, 2002, pp. 3-14.
    • (2002) Corrosion (Houston) , vol.58 , pp. 3-14
    • Buchheit, R.G.1    Mamidipally, S.B.2    Schmutz, P.3    Guan, H.4
  • 114
    • 0001789106 scopus 로고    scopus 로고
    • A correlation between salt spray and electrochemical impedance spectroscopy test results for conversion-coated aluminum alloys
    • Buchheit, R. G., Cunningham, M., Jensen, H., Kendig, M. W., Martinez, M. A., "A Correlation Between Salt Spray and Electrochemical Impedance Spectroscopy Test Results for Conversion-Coated Aluminum Alloys," Corrosion (Houston), Vol. 51, 1998, pp. 61-72.
    • (1998) Corrosion (Houston) , vol.51 , pp. 61-72
    • Buchheit, R.G.1    Cunningham, M.2    Jensen, H.3    Kendig, M.W.4    Martinez, M.A.5


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