Impact of biological factors on the ennoblement of stainless steel in Baltic seawater

Katri Mattila, Leena Carpén, Laura Raaska, Hanna-Leena Alakomi, Tero Hakkarainen, Mirja Salkinoja-Salonen

Research output: Contribution to journalArticleScientificpeer-review

7 Citations (Scopus)


Open circuit potentials of stainless steels increased when immersed in the Baltic Sea. The ennoblement potential was +200 mVsce in 40 to 50 days when sea water temperature was below 52°C and +300–400 mVsce within <40 days at around 102°C. Ennoblement occurred in a laboratory ecosystem at 232°C in 20 to 30 days, and at 262°C in <20 days, but no ennoblement occurred at A322°C within 40 days. By the time the ennoblement was complete, compact microcolonies covered 1–10% of the steel surface. Nutrient enrichment of Baltic Sea water by twofold above the natural levels increased microbial growth but attenuated open circuit potential increase of the stainless steels. Exposure of the ennobled stainless steels to similar levels of nutrients did not reverse the already developed open circuit potentials. Attenuation of the ennobling response of the stainless steels by increases of temperature and eutrophication suggests a role for microorganisms which is crucial for the electrochemical behaviour of steels in brackish Baltic Sea water
Original languageEnglish
Pages (from-to)410-420
JournalJournal of industrial microbiology and biotechnology
Issue number6
Publication statusPublished - 2000
MoE publication typeA1 Journal article-refereed


  • biofilm
  • stainless steel
  • ennoblement
  • Baltic Sea
  • season
  • laboratory ecosystem


Dive into the research topics of 'Impact of biological factors on the ennoblement of stainless steel in Baltic seawater'. Together they form a unique fingerprint.

Cite this