TY - JOUR
T1 - Ennoblement, corrosion, and biofouling in brackish seawater
T2 - Comparison between six stainless steel grades
AU - Huttunen-Saarivirta, E.
AU - Rajala, P.
AU - Marja-aho, M.
AU - Maukonen, J.
AU - Sohlberg, E.
AU - Carpén, L.
N1 - Funding Information:
The work was carried out within the Digital, Internet, Materials & Engineering Co-Creation (DIMECC) and its Breakthrough Steels and Applications (BSA) program. We gratefully acknowledge the financial support from the participating companies and the Finnish Funding Agency for Technology and Innovation ( Tekes ). VTT Technical Research Centre of Finland Ltd. is also acknowledged for funding. The laboratory personnel at VTT: Seppo Peltonen, Tiina Ikäläinen, Mirva Pyrhönen and Helena Hakuli are thanked for their skilful technical assistance in the experiments. Satu Salo at VTT is acknowledged for some of the microscopy work reported in the paper. Tvärminne zoological station is thanked for enabling the water acquisitions and Outokumpu Stainless Oy for the test materials.
Publisher Copyright:
© 2017 Elsevier B.V.
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - In this work, six common stainless steel grades were compared with respect to ennoblement characteristics, corrosion performance and tendency to biofouling in brackish sea water in a pilot-scale cooling water circuit. Two tests were performed, each employing three test materials, until differences between the materials were detected. Open circuit potential (OCP) was measured continuously in situ. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were conducted before and after the tests. Exposed specimens were further subjected to examinations by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), and the biofouling was studied using epifluorescence microscopy, quantitative polymerase chain reaction (qPCR) and high-throughput sequencing (HTP sequencing). The results revealed dissimilarities between the stainless steel grades in corrosion behaviour and biofouling tendency. The test material that differed from the most of the other studied alloys was grade EN 1.4162. It experienced fastest and most efficient ennoblement of OCP, its passive area shrank to the greatest extent and the cathodic reaction was accelerated to a significant degree by the development of biofilm. Furthermore, microbiological analyses revealed that bacterial community on EN 1.4162 was dominated by Actinobacteria, whereas on the other five test materials Proteobacteria was the main bacterial phylum.
AB - In this work, six common stainless steel grades were compared with respect to ennoblement characteristics, corrosion performance and tendency to biofouling in brackish sea water in a pilot-scale cooling water circuit. Two tests were performed, each employing three test materials, until differences between the materials were detected. Open circuit potential (OCP) was measured continuously in situ. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements were conducted before and after the tests. Exposed specimens were further subjected to examinations by scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), and the biofouling was studied using epifluorescence microscopy, quantitative polymerase chain reaction (qPCR) and high-throughput sequencing (HTP sequencing). The results revealed dissimilarities between the stainless steel grades in corrosion behaviour and biofouling tendency. The test material that differed from the most of the other studied alloys was grade EN 1.4162. It experienced fastest and most efficient ennoblement of OCP, its passive area shrank to the greatest extent and the cathodic reaction was accelerated to a significant degree by the development of biofilm. Furthermore, microbiological analyses revealed that bacterial community on EN 1.4162 was dominated by Actinobacteria, whereas on the other five test materials Proteobacteria was the main bacterial phylum.
KW - Biofouling
KW - Brackish sea water
KW - Electrochemical measurements
KW - Ennoblement
KW - Microbially induced corrosion (MIC)
KW - Stainless steel
U2 - 10.1016/j.bioelechem.2017.11.002
DO - 10.1016/j.bioelechem.2017.11.002
M3 - Article
AN - SCOPUS:85034110865
VL - 120
SP - 27
EP - 42
JO - Bioelectrochemistry
JF - Bioelectrochemistry
SN - 1567-5394
ER -