Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions

Iva Betova, Martin Bojinov, Timo Laitinen, Kari Mäkelä, Pekka Pohjanne, Timo Saario

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

Abstract

The transpassive corrosion of highly alloyed austenitic stainless steels - UNS NO8904, UNS S31254 and UNS S32654 - was investigated in simulated bleaching solutions containing 0.014 M SO42-, 0.017 M Cl-, up to 0.01 M oxalic acid and up to 0.0025 M diethylenetetraminepentaacetic acid (DTPA), pH 3.0 and 6.0, with conventional and rotating ring-disk electrode (RRDE) voltammetry, as well as electrochemical impedance spectroscopy (EIS). The transpassive oxidation rate of UNS S32654 was found to be much higher than that of the other two alloys. Oxalic acid addition resulted in a significant increase of the transpassive oxidation rate, whereas the addition of DTPA led to a decrease of that rate especially at a pH of 3. The general features of the impedance spectra demonstrate that transpassive dissolution is favoured for UNS S32654 and secondary passivation predominates for the two other steels. A kinetic model of the process is proposed, featuring a two-step transpassive dissolution of Cr via a Cr(VI) intermediate species and taking into account the dissolution of Fe(III) through the anodic film. The model has been found to be in quantitative agreement with steady state current vs. potential curves and impedance spectra. The kinetic parameters of transpassive dissolution have been determined and the relevance of their values is discussed.
Original languageEnglish
Title of host publication10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1
Place of PublicationEspoo
PublisherVTT Technical Research Centre of Finland
Pages323-336
ISBN (Electronic)951-38-5724-7
ISBN (Print)951-38-5720-4
Publication statusPublished - 2001
MoE publication typeA4 Article in a conference publication
Event10th International Symposium On corrosion in the Pulp and Paper Industry, ISCPPI - Helsinki, Finland
Duration: 21 Aug 200124 Aug 2001

Publication series

SeriesVTT Symposium
Number214
ISSN0357-9387

Conference

Conference10th International Symposium On corrosion in the Pulp and Paper Industry, ISCPPI
Abbreviated title10th ISCPPI
CountryFinland
CityHelsinki
Period21/08/0124/08/01

Fingerprint

Austenitic stainless steel
Bleaching
Dissolution
Corrosion
Oxalic Acid
Oxidation
Acids
Steel
Voltammetry
Electrochemical impedance spectroscopy
Kinetic parameters
Passivation
Electrodes
Kinetics

Cite this

Betova, I., Bojinov, M., Laitinen, T., Mäkelä, K., Pohjanne, P., & Saario, T. (2001). Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions. In 10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1 (pp. 323-336). Espoo: VTT Technical Research Centre of Finland. VTT Symposium, No. 214
Betova, Iva ; Bojinov, Martin ; Laitinen, Timo ; Mäkelä, Kari ; Pohjanne, Pekka ; Saario, Timo. / Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions. 10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1. Espoo : VTT Technical Research Centre of Finland, 2001. pp. 323-336 (VTT Symposium; No. 214).
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abstract = "The transpassive corrosion of highly alloyed austenitic stainless steels - UNS NO8904, UNS S31254 and UNS S32654 - was investigated in simulated bleaching solutions containing 0.014 M SO42-, 0.017 M Cl-, up to 0.01 M oxalic acid and up to 0.0025 M diethylenetetraminepentaacetic acid (DTPA), pH 3.0 and 6.0, with conventional and rotating ring-disk electrode (RRDE) voltammetry, as well as electrochemical impedance spectroscopy (EIS). The transpassive oxidation rate of UNS S32654 was found to be much higher than that of the other two alloys. Oxalic acid addition resulted in a significant increase of the transpassive oxidation rate, whereas the addition of DTPA led to a decrease of that rate especially at a pH of 3. The general features of the impedance spectra demonstrate that transpassive dissolution is favoured for UNS S32654 and secondary passivation predominates for the two other steels. A kinetic model of the process is proposed, featuring a two-step transpassive dissolution of Cr via a Cr(VI) intermediate species and taking into account the dissolution of Fe(III) through the anodic film. The model has been found to be in quantitative agreement with steady state current vs. potential curves and impedance spectra. The kinetic parameters of transpassive dissolution have been determined and the relevance of their values is discussed.",
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Betova, I, Bojinov, M, Laitinen, T, Mäkelä, K, Pohjanne, P & Saario, T 2001, Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions. in 10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1. VTT Technical Research Centre of Finland, Espoo, VTT Symposium, no. 214, pp. 323-336, 10th International Symposium On corrosion in the Pulp and Paper Industry, ISCPPI , Helsinki, Finland, 21/08/01.

Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions. / Betova, Iva; Bojinov, Martin; Laitinen, Timo; Mäkelä, Kari; Pohjanne, Pekka; Saario, Timo.

10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1. Espoo : VTT Technical Research Centre of Finland, 2001. p. 323-336 (VTT Symposium; No. 214).

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedingsScientificpeer-review

TY - GEN

T1 - Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions

AU - Betova, Iva

AU - Bojinov, Martin

AU - Laitinen, Timo

AU - Mäkelä, Kari

AU - Pohjanne, Pekka

AU - Saario, Timo

PY - 2001

Y1 - 2001

N2 - The transpassive corrosion of highly alloyed austenitic stainless steels - UNS NO8904, UNS S31254 and UNS S32654 - was investigated in simulated bleaching solutions containing 0.014 M SO42-, 0.017 M Cl-, up to 0.01 M oxalic acid and up to 0.0025 M diethylenetetraminepentaacetic acid (DTPA), pH 3.0 and 6.0, with conventional and rotating ring-disk electrode (RRDE) voltammetry, as well as electrochemical impedance spectroscopy (EIS). The transpassive oxidation rate of UNS S32654 was found to be much higher than that of the other two alloys. Oxalic acid addition resulted in a significant increase of the transpassive oxidation rate, whereas the addition of DTPA led to a decrease of that rate especially at a pH of 3. The general features of the impedance spectra demonstrate that transpassive dissolution is favoured for UNS S32654 and secondary passivation predominates for the two other steels. A kinetic model of the process is proposed, featuring a two-step transpassive dissolution of Cr via a Cr(VI) intermediate species and taking into account the dissolution of Fe(III) through the anodic film. The model has been found to be in quantitative agreement with steady state current vs. potential curves and impedance spectra. The kinetic parameters of transpassive dissolution have been determined and the relevance of their values is discussed.

AB - The transpassive corrosion of highly alloyed austenitic stainless steels - UNS NO8904, UNS S31254 and UNS S32654 - was investigated in simulated bleaching solutions containing 0.014 M SO42-, 0.017 M Cl-, up to 0.01 M oxalic acid and up to 0.0025 M diethylenetetraminepentaacetic acid (DTPA), pH 3.0 and 6.0, with conventional and rotating ring-disk electrode (RRDE) voltammetry, as well as electrochemical impedance spectroscopy (EIS). The transpassive oxidation rate of UNS S32654 was found to be much higher than that of the other two alloys. Oxalic acid addition resulted in a significant increase of the transpassive oxidation rate, whereas the addition of DTPA led to a decrease of that rate especially at a pH of 3. The general features of the impedance spectra demonstrate that transpassive dissolution is favoured for UNS S32654 and secondary passivation predominates for the two other steels. A kinetic model of the process is proposed, featuring a two-step transpassive dissolution of Cr via a Cr(VI) intermediate species and taking into account the dissolution of Fe(III) through the anodic film. The model has been found to be in quantitative agreement with steady state current vs. potential curves and impedance spectra. The kinetic parameters of transpassive dissolution have been determined and the relevance of their values is discussed.

M3 - Conference article in proceedings

SN - 951-38-5720-4

T3 - VTT Symposium

SP - 323

EP - 336

BT - 10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1

PB - VTT Technical Research Centre of Finland

CY - Espoo

ER -

Betova I, Bojinov M, Laitinen T, Mäkelä K, Pohjanne P, Saario T. Transpassive corrosion mechanism of austenitic stainless steels in simulated bleaching solutions. In 10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1. Espoo: VTT Technical Research Centre of Finland. 2001. p. 323-336. (VTT Symposium; No. 214).