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Microbiological influence on the electro‐chemical potential of stainless steel
Author(s) -
Gümpel P.,
Arlt N.,
Telegdi J.,
Schiller D.,
Moos O.
Publication year - 2006
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.200503962
Subject(s) - metallurgy , corrosion , manganese , materials science , annealing (glass) , biocide , alloy , open circuit voltage , chemistry , voltage , physics , organic chemistry , quantum mechanics
The microbiologically caused ennoblement appears in natural water on all stainless steels equally and can only be prevented by the use of biocides. Temperature and supply of nutrients have an influence on the increasing rate of the potential, as well as the presence of manganese ions in the water favors the potential rise. The final value of the potential is substantially regulated by the biological system and is independent of the steel composition. An endangerment of stainless steels by a selective corrosion attack e.g. pitting corrosion arises if the critical repassivation potential of the steel lies below the open‐circuit potential appearing in the natural system. This can be due to the alloy composition or due to process‐conditioned weakening of the passive layer, for example by annealing colors on and beside welded joints.