•  
  •  
 

Corresponding Author

Wei-shan LI(liwsh@scnu.edu.cn)

Abstract

The formation process of passive film on iron and electronic properties and pitting susceptibility of an iron-based alloy are investigated by using linear potential sweep, alternative current impedance and electrochemical nose technologies. The relationship between reciprocal square capacitance and potential following the Mott-Schottky behavior is limited at a narrow rang of low potentials. At higher potentials, linear relationship between reciprocal capacitance and potential is obtained, which is ascribed to the increasing thickness of the passive film with potential. The donor density of the passive film is influenced by the formation potential of the film, passivator and microstructure. The decrease in the formation potential of the passive film and the existence of reduced or deposited passivator can increase the donor density of the passive film and lead to low resistance to pitting corrosion. The high-to-low order of pitting susceptibility for the individual microstructure is ferrite> martensite>pearlite. There exists interaction between different microstructures with different donor density, which results in pitting initiation and propagation on the weak microstructure.

Keywords

Iron-based alloy, Passive film, Electronic property, Pitting susceptibility

Publication Date

2004-11-28

Online Available Date

2004-11-28

Revised Date

2004-11-28

Received Date

2004-11-28

References

[1] BojinovM,LaitinenT,M kel K,etal.,Conductionmechanismofthepassivefilmonironbasedoncontactelectricimpedanceandresistancemeasurements[J].J.Electrochem.Soc.,2001,148:B243.
[2] Diez-PerezI,GorostizaP,SanzF,etal.,Firststageofelectrochemicalgrowthofthepassivefilmoniron[J].J.Electrochem.Soc.2001,148:B307.
[3] KrishnamurthyB,WhiteRE,PloehnHJ.Simplifiedpointdefectmodelforgrowthofanodicpassivefilmsoniron[J].Electrochim.Acta,2002,47:3375.
[4] WellsAF.StructuralInorganicChemistry[M].Oxford:CarendonPress,1984.
[5] ReesEE,RyanMP,McPhailDS.AnSTMstudyofthenanocrystallinestructureofthepassivefilmoniron[J].Electrochem.Solid-StateLetters,2002,5:B21.
[6] LiWS,CaiCQ,LuoJL.Chronopotentiometricresponsesandcapacitancebehaviorsofpassivefilmformedonironinboratebuffersolution[J].J.Electrochem.Soc.,2004,151,B220.
[7] LiWS,LuoJL.Electronicpropertiesandpittingsusceptibilityofpassivefilmsformedonironinchromatesolution[J].ElectrochemistryCommunications,1999,1:349.
[8] LiWS,LuoJL.Uniformityofpassivefilmsformedonferriteandmartensitebydifferentinorganicinhibitors[J].CorrosionScience,2002,44:1695.
[9] LiWS,CuiN,LuoJL.Pittinginitiationandpropagationofhypoeutectoidiron-basedalloywithinclusionsofmartensiteinchloride-containingnitritesolutions[J].Electrochim.Acta,2004,49:1663.
[10] LiWS,LuoJL.Pittingcorrosioninducedbytheinteractionbetweenmicrostructuresofiron-basedalloyinchloride-containingsolution[J].J.Mater.Sci.Letters,2002,21:1195.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.