Marine Corrosion of Stainless Steels - Chlorination and Microbial Effects

217 Pages·1993·10.69 MB·English

European Federation of Corrosion
Publications
NUMBER 10
A Working Party Report on
Marine Corrosion of
Stainless Steels:
Chlorination and Microbial
Effects
Published for the European Federation of Corrosion
by The Institute of Materials
THE INSTITUTE OF MATERIALS
1993
Book Number 546
Published in 1993 by The Institute of Materials
1 Carlton House Terrace, London SWlY 5DB
01 993 The Institute of Materials
All rights reserved
British Library Cataloguing in Publication Data
Available on request
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ISBN 0-901716-33-2
Neither the EFC nor The Institute of Materials are responsible
for any views expressed which are the sole responsibility of the authors
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Contents
Series Introduction viii
Introduction ix
INTRODUCTORPYA PERS
1. Aspects of Marine Corrosion and Testing for Seawater Applications 1
F . P . IJsseling
2. Microbial and Biochemical Factors Affecting the Corrosion Behaviour
of Stainless Steels in Seawater 21
V. Scotto, M. Beggiato, G. Marcenaro and R. Dellepiane
EXPERIENCE
3. Marine Corrosion Tests on Metal Alloys in Antarctica: 36
Preliminary results
G. Alabiso, U.M ont in i , A. Mollica, M. Beggiato, V. Scotto,
G. Marcenaro and R. Dellepiane
4. North Sea Experience with the Use of Stainless Steels in 48
Seawater Applications
R. Johnsen
CHLORINATION
5. Seawater Chlorination 60
C . M adec, F . Quentel and R. Riso
6. Experiences with Seawater Chlorination on Copper Alloys and 73
Stainless Steels
P. Gallagher, A. Nieuwhof and R. J . M . Tausk
V
Marine Corrosion of Stainless Steels: Chlorination and Microbial Effects
7. Corrosion of Stainless Steels caused by Bromine Emission from 92
Chlorinated Seawater
J. W. Oldfield and B. Todd
TESTING
8. Improved Method for Measuring Polarisation Curves of 100
Alloys During Prolonged Times of Exposure
F . P. IJsseling
9. Application of Electrochemical Impedance Spectroscopy to Monitor 108
Seawater Fouling on Stainless Steels and Copper Alloys
D. Fkron
10. Effect of Temperature on Inititation, Repassivation and Propagation 114
of Crevice Corrosion of High-Alloyed Stainless Steels in Natural
Seawater
S. Valen, P. 0.G artland and U. Steinsmo
11. An Intelligent Probe for in situ Assessment of Susceptibility of 128
Hydrogen Induced Cracking of Steel for Offshore Platform Joints
W. Wei, D. Peng, F . Chao, L. Zhengand D. Yuan-long
12. Aspects of Testing Stainless Steels for Seawater Applications 134
P. 0.G artland
13. Biofilm Monitoring in Seawater 149
A. Mollica, E . Traverso and G. Ventura
MECHANISM
14. Identification of Sulphated Green Rust 2 Compound Produced 162
as a Result of Microbially Induced Corrosion of Steel Sheet Piles
in a Harbour
J.-M. R. Gknin, A. A. Olowe, 8. Resiak, N . D. Benbouzid-Rollet,
M . Confente and D. Prieur
15.T he Role of Green Rust Compounds in Aqueous Corrosion of Iron in 167
Aggressive Media Close to a Marine Environment
Ph. Refait, J.-M. R. Ge'nin and A. A. Olowe
vi
Contents
PROTECTION
16. The Cathodic Protection of Steel for Offshore Platforms in Polluted 190
Seawater
D. Yuan-long, F. Chao, L. Zheng and W . Wei
17.T hermal Sprayed Aluminium Coatings in Seawater with and without 195
Cathodic Protection
P. 0. Gartland and T. G. Eggen
vii
Introduction
This volume contains the papers which were presented at two recent symposia:
International Workshop on Stainless Steels and Chlorination in Seawater, Brest,
29-30 May, 1991 (EFC Event no. 186), organised by IFREMER Centre de Brest with
support from the EFC Working Party on Marine Corrosion.
International Symposium on Marine and Microbial Corrosion, Stockholm,
30 September-2 October, 1991 (EFC Event no. 184), organised by the Swedish
Corrosion Institute with support from the EFC Working Parties on Microbial Corrosion
and Marine Corrosion.
Many topics of current interest were covered, including papers on microbial corrosion,
testing and monitoring, mechanisms, chlorination of seawater, the application of stainless
steels in seawater environment and corrosion protection.
Some of the papers presented at the conference were omitted from this publication since
they had been published elsewhere.
The majority of the papers in the present volume represent the experience of European
authors, although two papers originate from the People’s Republic of China. A broad
classification of topics had been made, thus Introductory Papers are followed by Experience
Papers and then by papers on the specific subjects of Chlorination, Testing Methods (including
monitoring), Mechanisms and Protection. The classification is not exclusive since many papers
could be associated with more than one topic.
Both conferences demonstrated the necessity to attack the marine corrosion problem in an
interdisciplinary way.
F. P. IJsseling
Chairman, Marine Corrosion Working Party
D. Thierry
Chairman, Microbial Corrosion Working Party
X
European Federation of Corrosion Publications
Series Introduction
The EFC, incorporated in Belgium, was founded in 1955 with the purpose of promoting
European co-operation in the fields of research into corrosion and corrosion prevention.
Membership is based upon participation by corrosion societies and committees in
technical Working Parties. Member societies appoint delegates to Working Parties, whose
membership is expanded by personal corresponding membership.
The activities of the Working Parties cover corrosion topics associated with inhibition,
education, reinforcement in concrete, microbial effects, hot gases and combustion prod-
ucts, environment sensitive fracture, marine environments, surface science, physico-
chemical methods of measurement, the nuclear industry, computer based information
systems and corrosion in the oil and gas industry. Working Parties on other topics are
established as required.
The Working Parties function in various ways, e.g. by preparing reports, organising
symposia, conducting intensive courses and producing instructional material, including
films. The activities of the Working Parties are co-ordinated, through a Science and
Technology Advisory Committee, by the Scientific Secretary.
The administration of the EFC is handled by three Secretariats: DECHEMA e. V. in
Germany, the SociCtC de Chimie Industrielle in France, and The Institute of Materials in the
United Kingdom. These three Secretariatsm eet at the Board of Administrators of the EFC.
There is an annual General Assembly at which delegates from all member societies meet
to determine and approve EFC policy. News of EFC activities, forthcoming conferences,
courses etc. is published in a range of accredited corrosion and certain other journals
throughout Europe. More detailed descriptions of activities are given in a Newsletter
prepared by the Scientific Secretary.
The output of the EFC takes various forms. Papers on particular topics, for example,
reviews or results of experimental work, may be published in scientific and technical
journals in one or more countries in Europe. Conference proceedings are often published
by the organisation responsible for the conference.
In 1987 the, then, Institute of Metals was appointed as the official EFC publisher.
Although the arrangement is non-exclusive and other routes for publication are still
available, it is expected that the Working Parties of the EFC will use The Institute of Materials
for publication of reports, proceedings etc. wherever possible.
The name of The Institute of Metals was changed to The Institute of Materials with effect
from 1J anuary 1992.
A. D. Mercer
EFC Scientific Secretary,
The Institute of Materials, London, UK
viii
Series Introduction
EFC Secretariats are located at:
Dr J A Catterall
European Federation of Corrosion, The Institute of Materials, 1 Carlton House Terrace,
London, SWlY 5DB, UK
Mr R Mas
Federation Europeene de la Corrosion,S ocietk de Chimie Industrielle, 28 rue Saint-Dominique,
F-75007 Paris, FRANCE
Professor Dr G Kreysa
Europaische Foderation Korrosion, DECHEMA e. V., Theodor-Heuss-Allee2 5, P.O.B. 150104,
D-6000 Frankfurt M 15, GERMANY
ix
INTRODUCTORPYA PERS
Aspects of Marine Corrosion and Testing for
Seawater Applications
F. P . IJSSELING
Corrosion Laboratory, Royal Netherlands Naval College (Harssens), c/o Marinepostkamer, PB 10 000,1780 CA,
Den Helder, The Netherlands
Abstract
A brief review is given of the main factors which make seawater such a corrosive fluid. Some
modern developments in marine corrosion control and the peculiarities of marine corrosion
testing are discussed.
1. Introduction
The corrosive nature of seawater has already been widely documented 11-71. The main factors
which make seawater such a corrosive fluid are now discussed briefly. These factors are
divided in two groups: (biokhemical (i.e. oxygen, carbonate, salts, organic compounds,
biochemical activity and pollutants) and physical (i.e. temperature, flow velocity, potential,
pressure and light).
The methods of corrosion control are reviewed with emphasis on those methods which find
a wide application in the marine environment.
Finally, corrosion testing in general and the peculiarities of marine corrosion testing, in
particular the use of natural seawater, stored or recirculated seawater and synthetic solutions
for testing purposes is discussed.
2. Corrosion in Seawater
Corrosion in seawater is due to the interaction between the material and the environment,
caused by electrochemical reactions which occur at the metal surface. It is well known that
corrosion is not a specific materials property such as density, but depends on a large number
of variables. A number of these are connected with the alloy, e.g. overall chemical composition,
microstructure and surface state. Others are related to the environment, such as type and
concentration of redox system(s) which may provoke the corrosion reaction, the presence of
compounds which form stable complexes with the dissolved metal ions, etc.
Finally there are a number of physical factors which-depending on the particular sys-
tem-may exert a considerable influence. Examples of these are potential, temperature, stress
and flow velocity.
Generally seawater from the open seus can be considered as a dynamic aqueous system,
containing dissolved salts, gases and organic compounds, undissolved material and living
organisms. The dissolved inorganic material comprises almost all known elements, sometimes
found in several ionic and molecular forms (Table 1).
The major constituents, as shown in the table, account for over 99.85% of the total dissolved
salts. The variations in the concentrations of these species with location and depth are generally
rather small. Of the minor components dissolved 0, and CO, are particularly important.
Dissolved CO, is part of the well-known carbonate/bicarbonate equilibrium reactions (Fig. l),
1