Cracking of recovery boiler composite tubes: Thermal fatigue or stress corrosion cracking?

Hannu Hänninen, Pekka Pohjanne, Pekka Saarinen, Kiesi

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

    Abstract

    In the composite tubes of black liquor recovery boilers cracking and corrosion attack has been observed, especially in the floor tubes. Cracks typically initiate in the stainless steel cladding and penetrate through the cladding to the stainless steel/low alloy steel interface, where the cracks normally propagate along the interface and do not penetrate to the low alloy steel. Cracking occurs also on lower walls, smelt spout openings and air ports and sometimes penetration to low alloy steel base metal has also occurred. The cracking mechanism has been suggested to be either stress corrosion cracking or thermal fatigue. A special case of cracking has been the situation where cracks are present on the inner surface of the tubes, when cracking is also starting from the water side. The environmental, thermal, mechanical and metallurgical effects on these cracking phenomena are evaluated based on these two different mechanisms of cracking. Special attention is paid to the possible methods for mitigation of the recovery boiler cracking failures, e.g. by operating procedures or materials selection.
    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
    Pages103-116
    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

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  • Cite this

    Hänninen, H., Pohjanne, P., Saarinen, P., & Kiesi (2001). Cracking of recovery boiler composite tubes: Thermal fatigue or stress corrosion cracking? In 10th International Symposium on Corrosion in the Pulp and Paper Industry, ISCPPI. Vol. 1 (pp. 103-116). VTT Technical Research Centre of Finland. VTT Symposium, No. 214