Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions

Heikki Leinonen, Pekka Pohjanne, Tapio Saukkonen, Tanja Schildt, Jyrki Romu, Hannu Hänninen

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

Abstract

The formation of nickel-rich layers on austenitic stainless steels in strong caustic solutions was reported in 1970's.
Recently, a more detailed study has shown the nature of the de-alloying process and established firm links with the other metal-environment systems that show de-alloying and associated stress corrosion cracking (SCC) in strong caustic environments. In this study, the role of de-alloying in SCC of the austenitic and duplex stainless steel AISI 304 (EN1.4301) and S322205 (EN1.4462) is evaluated in 50% NaOH and also in NaCl/Na2S containing caustic environments (pulping liquors) at 413 K (140ºC) and 463 K (190ºC).
The results show that selective dissolution of alloying elements occurs on surface of the specimens and at the crack tip and strain is necessary for selective dissolution. The proposal that the rate determining step in SCC is generation of vacancies by selective dissolution at the crack tip will be confirmed in the further detailed examinations.
Chromium, iron and molybdenum are dissolving selectively and/or precipitating during the process which affects the general corrosion and SCC susceptibility depending on the alloy composition and microstructure of the steel.
FEG-SEM examination shows that the de-alloyed layer exhibits extremely fine nanoporosity.
Original languageEnglish
Title of host publicationProceedings
Subtitle of host publicationCorrosion 2011, Conference & Expo
Place of PublicationHouston, TX
Number of pages17
Volume2
Publication statusPublished - 2011
MoE publication typeA4 Article in a conference publication
EventCorrosion 2011, Conference & Expo  - Houston, TX, United States
Duration: 13 Mar 201117 Mar 2011

Conference

ConferenceCorrosion 2011, Conference & Expo 
CountryUnited States
CityHouston, TX
Period13/03/1117/03/11

Fingerprint

Stress corrosion cracking
Dissolution
Stainless steel
Alloying
Crack tips
Alloying elements
Austenitic stainless steel
Molybdenum
Vacancies
Chromium
Nickel
Corrosion
Iron
Microstructure
Scanning electron microscopy
Steel
Metals
Chemical analysis

Keywords

  • selective dissolution
  • de-alloying
  • duplex stainless steel
  • austenitic stainless steel
  • stress corrosion cracking
  • caustic solution

Cite this

Leinonen, H., Pohjanne, P., Saukkonen, T., Schildt, T., Romu, J., & Hänninen, H. (2011). Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions. In Proceedings: Corrosion 2011, Conference & Expo (Vol. 2). [11160] Houston, TX.
Leinonen, Heikki ; Pohjanne, Pekka ; Saukkonen, Tapio ; Schildt, Tanja ; Romu, Jyrki ; Hänninen, Hannu. / Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions. Proceedings: Corrosion 2011, Conference & Expo . Vol. 2 Houston, TX, 2011.
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abstract = "The formation of nickel-rich layers on austenitic stainless steels in strong caustic solutions was reported in 1970's. Recently, a more detailed study has shown the nature of the de-alloying process and established firm links with the other metal-environment systems that show de-alloying and associated stress corrosion cracking (SCC) in strong caustic environments. In this study, the role of de-alloying in SCC of the austenitic and duplex stainless steel AISI 304 (EN1.4301) and S322205 (EN1.4462) is evaluated in 50{\%} NaOH and also in NaCl/Na2S containing caustic environments (pulping liquors) at 413 K (140ºC) and 463 K (190ºC). The results show that selective dissolution of alloying elements occurs on surface of the specimens and at the crack tip and strain is necessary for selective dissolution. The proposal that the rate determining step in SCC is generation of vacancies by selective dissolution at the crack tip will be confirmed in the further detailed examinations. Chromium, iron and molybdenum are dissolving selectively and/or precipitating during the process which affects the general corrosion and SCC susceptibility depending on the alloy composition and microstructure of the steel. FEG-SEM examination shows that the de-alloyed layer exhibits extremely fine nanoporosity.",
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author = "Heikki Leinonen and Pekka Pohjanne and Tapio Saukkonen and Tanja Schildt and Jyrki Romu and Hannu H{\"a}nninen",
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Leinonen, H, Pohjanne, P, Saukkonen, T, Schildt, T, Romu, J & Hänninen, H 2011, Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions. in Proceedings: Corrosion 2011, Conference & Expo . vol. 2, 11160, Houston, TX, Corrosion 2011, Conference & Expo , Houston, TX, United States, 13/03/11.

Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions. / Leinonen, Heikki; Pohjanne, Pekka; Saukkonen, Tapio; Schildt, Tanja; Romu, Jyrki; Hänninen, Hannu.

Proceedings: Corrosion 2011, Conference & Expo . Vol. 2 Houston, TX, 2011. 11160.

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

TY - GEN

T1 - Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions

AU - Leinonen, Heikki

AU - Pohjanne, Pekka

AU - Saukkonen, Tapio

AU - Schildt, Tanja

AU - Romu, Jyrki

AU - Hänninen, Hannu

PY - 2011

Y1 - 2011

N2 - The formation of nickel-rich layers on austenitic stainless steels in strong caustic solutions was reported in 1970's. Recently, a more detailed study has shown the nature of the de-alloying process and established firm links with the other metal-environment systems that show de-alloying and associated stress corrosion cracking (SCC) in strong caustic environments. In this study, the role of de-alloying in SCC of the austenitic and duplex stainless steel AISI 304 (EN1.4301) and S322205 (EN1.4462) is evaluated in 50% NaOH and also in NaCl/Na2S containing caustic environments (pulping liquors) at 413 K (140ºC) and 463 K (190ºC). The results show that selective dissolution of alloying elements occurs on surface of the specimens and at the crack tip and strain is necessary for selective dissolution. The proposal that the rate determining step in SCC is generation of vacancies by selective dissolution at the crack tip will be confirmed in the further detailed examinations. Chromium, iron and molybdenum are dissolving selectively and/or precipitating during the process which affects the general corrosion and SCC susceptibility depending on the alloy composition and microstructure of the steel. FEG-SEM examination shows that the de-alloyed layer exhibits extremely fine nanoporosity.

AB - The formation of nickel-rich layers on austenitic stainless steels in strong caustic solutions was reported in 1970's. Recently, a more detailed study has shown the nature of the de-alloying process and established firm links with the other metal-environment systems that show de-alloying and associated stress corrosion cracking (SCC) in strong caustic environments. In this study, the role of de-alloying in SCC of the austenitic and duplex stainless steel AISI 304 (EN1.4301) and S322205 (EN1.4462) is evaluated in 50% NaOH and also in NaCl/Na2S containing caustic environments (pulping liquors) at 413 K (140ºC) and 463 K (190ºC). The results show that selective dissolution of alloying elements occurs on surface of the specimens and at the crack tip and strain is necessary for selective dissolution. The proposal that the rate determining step in SCC is generation of vacancies by selective dissolution at the crack tip will be confirmed in the further detailed examinations. Chromium, iron and molybdenum are dissolving selectively and/or precipitating during the process which affects the general corrosion and SCC susceptibility depending on the alloy composition and microstructure of the steel. FEG-SEM examination shows that the de-alloyed layer exhibits extremely fine nanoporosity.

KW - selective dissolution

KW - de-alloying

KW - duplex stainless steel

KW - austenitic stainless steel

KW - stress corrosion cracking

KW - caustic solution

M3 - Conference article in proceedings

SN - 978-1-6178-2593-4

VL - 2

BT - Proceedings

CY - Houston, TX

ER -

Leinonen H, Pohjanne P, Saukkonen T, Schildt T, Romu J, Hänninen H. Effect of selective dissolution on stress corrosion cracking susceptibility of austenitic and duplex stainless steels in alkaline solutions. In Proceedings: Corrosion 2011, Conference & Expo . Vol. 2. Houston, TX. 2011. 11160