Stress corrosion cracking susceptibility of stainless steels in pulp cooking processes - Online capillary electrophoresis, potentiostatic and chromatographic studies

Heikki Leinonen, Heli Sirén, Pertti Vastamäki, Stella Rovio, Soili Peltonen, Teemu Työppönen, Jaakko Rämö

Research output: Contribution to journalArticleScientificpeer-review

5 Citations (Scopus)

Abstract

An online high temperature capillary electrophoresis instrument (HotUCE), a potentiometer and an ion chromatograph were used in studies on corrosive ions and changes in potential at normal pulping process temperatures in experimental liquors modelling pulp cooking processes at mills. The aim was to evaluate the stress corrosion cracking (SCC) susceptibility of stainless steels. The HotUCE instrument and the potentiometer were online coupled with an autoclave, where welded duplex stainless steel samples were immersed for 500 h in simulated high ionic strength hot black liquor (HBL), hot white liquor (HWL) or green liquor (GL) at 130, 150 or 170 °C, respectively.

The results showed that only minor amounts of oxidized sulphur compounds were formed. The concentrations of corrosive sulphur anions were calculated against sulphur standards. Amounts of sulphur species in the liquor correlated with the changes in the potential of the duplex stainless steel specimens during the cooking experiments. The formation of sulphite during cooking was greater in HWL than in HBL. Changes in the potential showed that reduction processes occurred during the SCC tests. The results indicate that the SCC risk is enhanced at higher temperatures, probably, due to the increased formation of thiosulphate.
Original languageEnglish
Pages (from-to)653 - 661
JournalMaterials and Corrosion
Volume59
Issue number8
DOIs
Publication statusPublished - 2008
MoE publication typeA1 Journal article-refereed

Fingerprint

Pulp cooking
Capillary electrophoresis
Stainless Steel
Stress corrosion cracking
Sulfur
corrosion
electrokinesis
Caustics
Stainless steel
duplex
steel
sulfur
Ions
Sulfur Compounds
Thiosulfates
Sulfites
Sulfur compounds
ion
thiosulfate
sulfite

Keywords

  • analysis
  • online measurements
  • stainless steels
  • stress corrosion cracking
  • cracking
  • cracking (fracturing)

Cite this

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title = "Stress corrosion cracking susceptibility of stainless steels in pulp cooking processes - Online capillary electrophoresis, potentiostatic and chromatographic studies",
abstract = "An online high temperature capillary electrophoresis instrument (HotUCE), a potentiometer and an ion chromatograph were used in studies on corrosive ions and changes in potential at normal pulping process temperatures in experimental liquors modelling pulp cooking processes at mills. The aim was to evaluate the stress corrosion cracking (SCC) susceptibility of stainless steels. The HotUCE instrument and the potentiometer were online coupled with an autoclave, where welded duplex stainless steel samples were immersed for 500 h in simulated high ionic strength hot black liquor (HBL), hot white liquor (HWL) or green liquor (GL) at 130, 150 or 170 °C, respectively. The results showed that only minor amounts of oxidized sulphur compounds were formed. The concentrations of corrosive sulphur anions were calculated against sulphur standards. Amounts of sulphur species in the liquor correlated with the changes in the potential of the duplex stainless steel specimens during the cooking experiments. The formation of sulphite during cooking was greater in HWL than in HBL. Changes in the potential showed that reduction processes occurred during the SCC tests. The results indicate that the SCC risk is enhanced at higher temperatures, probably, due to the increased formation of thiosulphate.",
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author = "Heikki Leinonen and Heli Sir{\'e}n and Pertti Vastam{\"a}ki and Stella Rovio and Soili Peltonen and Teemu Ty{\"o}pp{\"o}nen and Jaakko R{\"a}m{\"o}",
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Stress corrosion cracking susceptibility of stainless steels in pulp cooking processes - Online capillary electrophoresis, potentiostatic and chromatographic studies. / Leinonen, Heikki; Sirén, Heli; Vastamäki, Pertti; Rovio, Stella; Peltonen, Soili; Työppönen, Teemu; Rämö, Jaakko.

In: Materials and Corrosion, Vol. 59, No. 8, 2008, p. 653 - 661.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Stress corrosion cracking susceptibility of stainless steels in pulp cooking processes - Online capillary electrophoresis, potentiostatic and chromatographic studies

AU - Leinonen, Heikki

AU - Sirén, Heli

AU - Vastamäki, Pertti

AU - Rovio, Stella

AU - Peltonen, Soili

AU - Työppönen, Teemu

AU - Rämö, Jaakko

PY - 2008

Y1 - 2008

N2 - An online high temperature capillary electrophoresis instrument (HotUCE), a potentiometer and an ion chromatograph were used in studies on corrosive ions and changes in potential at normal pulping process temperatures in experimental liquors modelling pulp cooking processes at mills. The aim was to evaluate the stress corrosion cracking (SCC) susceptibility of stainless steels. The HotUCE instrument and the potentiometer were online coupled with an autoclave, where welded duplex stainless steel samples were immersed for 500 h in simulated high ionic strength hot black liquor (HBL), hot white liquor (HWL) or green liquor (GL) at 130, 150 or 170 °C, respectively. The results showed that only minor amounts of oxidized sulphur compounds were formed. The concentrations of corrosive sulphur anions were calculated against sulphur standards. Amounts of sulphur species in the liquor correlated with the changes in the potential of the duplex stainless steel specimens during the cooking experiments. The formation of sulphite during cooking was greater in HWL than in HBL. Changes in the potential showed that reduction processes occurred during the SCC tests. The results indicate that the SCC risk is enhanced at higher temperatures, probably, due to the increased formation of thiosulphate.

AB - An online high temperature capillary electrophoresis instrument (HotUCE), a potentiometer and an ion chromatograph were used in studies on corrosive ions and changes in potential at normal pulping process temperatures in experimental liquors modelling pulp cooking processes at mills. The aim was to evaluate the stress corrosion cracking (SCC) susceptibility of stainless steels. The HotUCE instrument and the potentiometer were online coupled with an autoclave, where welded duplex stainless steel samples were immersed for 500 h in simulated high ionic strength hot black liquor (HBL), hot white liquor (HWL) or green liquor (GL) at 130, 150 or 170 °C, respectively. The results showed that only minor amounts of oxidized sulphur compounds were formed. The concentrations of corrosive sulphur anions were calculated against sulphur standards. Amounts of sulphur species in the liquor correlated with the changes in the potential of the duplex stainless steel specimens during the cooking experiments. The formation of sulphite during cooking was greater in HWL than in HBL. Changes in the potential showed that reduction processes occurred during the SCC tests. The results indicate that the SCC risk is enhanced at higher temperatures, probably, due to the increased formation of thiosulphate.

KW - analysis

KW - online measurements

KW - stainless steels

KW - stress corrosion cracking

KW - cracking

KW - cracking (fracturing)

U2 - 10.1002/maco.200804113

DO - 10.1002/maco.200804113

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VL - 59

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EP - 661

JO - Materials and Corrosion

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SN - 0947-5117

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