Search
Filters
Close

51313-02149-Investigation of Pseudo-Passiviation Behavior of Iron Carbonate Layer in CO2 Corrosion

Product Number: 51313-02149-SG
ISBN: 02149 2013 CP
Author: Wei Li
Publication Date: 2013
$0.00
$20.00
$20.00

The corrosion product layer developed in sweet conditions is known to play a role in the retardation of corrosion but may also lead to initiation of localized corrosion. An incomplete pseudo-passive layer can initiate and propagate localized corrosion by developing a galvanic cell between a bare steel surface and a surface that is covered with iron carbonate layer due to their respective potentials. The mechanisms related to this phenomenon require further study. In this work a pseudo-passive effect of the CO2 corrosion product layer on the steel surface has been investigated at 80oC over a relatively wide bulk pH range. Experiments were done in a 2L glass cell using a three electrode system. Electrochemical techniques such as linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) were conducted and surface analysis techniques (SEM XRD TEM) were used to confirm the composition and structure of the pseudo-passive layer. Experimental results show that a pseudo-passive layer did form with a positive open circuit potential shift and a significantly retarded corrosion rate in systems at 80oC 0.53 bar CO2 pH 6.0 and above; but a stable and protective pseudo-passive layer could not be achieved at pH 5.6 or lower.

Keywords: CO2 corrosion product layer; pseudo-passivation; electrochemical techniques; SEM; XRD; TEM.
 

The corrosion product layer developed in sweet conditions is known to play a role in the retardation of corrosion but may also lead to initiation of localized corrosion. An incomplete pseudo-passive layer can initiate and propagate localized corrosion by developing a galvanic cell between a bare steel surface and a surface that is covered with iron carbonate layer due to their respective potentials. The mechanisms related to this phenomenon require further study. In this work a pseudo-passive effect of the CO2 corrosion product layer on the steel surface has been investigated at 80oC over a relatively wide bulk pH range. Experiments were done in a 2L glass cell using a three electrode system. Electrochemical techniques such as linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) were conducted and surface analysis techniques (SEM XRD TEM) were used to confirm the composition and structure of the pseudo-passive layer. Experimental results show that a pseudo-passive layer did form with a positive open circuit potential shift and a significantly retarded corrosion rate in systems at 80oC 0.53 bar CO2 pH 6.0 and above; but a stable and protective pseudo-passive layer could not be achieved at pH 5.6 or lower.

Keywords: CO2 corrosion product layer; pseudo-passivation; electrochemical techniques; SEM; XRD; TEM.
 

Product tags
Also Purchased
Picture for Localized Corrosion of Mild Steel under Silica Deposits in Inhibited Aqueous CO2 solutions
Available for download

51313-02144-Localized Corrosion of Mild Steel under Silica Deposits in Inhibited Aqueous CO2 solutions

Product Number: 51313-02144-SG
ISBN: 02144 2013 CP
Author: Jin Huang
Publication Date: 2013
$20.00
Picture for Portable Online 4-Probe Sensor for Simultaneous Monitoring of Corrosion Rate and SRB Activity
Available for download

51313-02148-Portable Online 4-Probe Sensor for Simultaneous Monitoring of Corrosion Rate and SRB Activity

Product Number: 51313-02148-SG
ISBN: 02148 2013 CP
Author: Sankara Papavinasam
Publication Date: 2013
$20.00
Picture for Condition Assessment of 27 Years Old Concrete Cylinder Pipes (CCP) Buried in Saline Soils
Available for download

51313-02153-Condition Assessment of 27 Years Old Concrete Cylinder Pipes (CCP) Buried in Saline Soils

Product Number: 51313-02153-SG
ISBN: 02153 2013 CP
Author: Zia Chaudhary
Publication Date: 2013
$20.00