Corrodys

Auteur(s) : Ph. Refait, M. Jeannin, R. Sabot, H. Antony, S. Pineau

Résumé : Carbon steel coupons were set in the tidal zone of a French seaport for 7 years with or without cathodic protection. The average corrosion rates decreased from 90 lmyr1 to 9 lmyr1 under cathodic protection. The corrosion product layers covering the unprotected coupons, characterized by Raman spectroscopy and X-ray diffraction, were mainly made up of magnetite and Fe(III) oxyhydroxides, with magnetite being clearly predominant. The products of the residual corrosion process under cathodic protection, similar to those observed at open circuit potential, formed a thin layer on the steel surface under the calcareous deposit.

Corrosion Science 90 (2015) 375–382
Date de Publication (en ligne) : 30 octobre 2014

Voir la publication sur Science direct

Auteur(s) : Florence Marty, Hervé Gueuné, Emilie Malard, José M. Sánchez-Amaya, Lena Sjögren, Ben Abbas, Laurent Quillet, Mark C.M. van Loosdrecht and Gerard Muyzer

Résumé : Biotic and abiotic factors favoring Accelerated Low Water Corrosion (ALWC) on harbor steel structures remain unclear warranting their study under controlled experimental tidal conditions. Initial stimulation of marine microbial consortia by a pulse of organic matter resulted in localized corrosion and the highest corrosion rates (up to 12-times higher than non-stimulated conditions) in the low water zone, persisting after nine months exposure to natural seawater. Correlations between corrosion severity and the abundance and composition of metabolically active sulfate-reducing bacteria (SRB) indicated the importance and persistence of specific bacterial populations in accelerated corrosion. One phylotype related to the electrogenic SRB Desulfopila corrodens appeared as the major causative agent of the accelerated corrosion. The similarity of bacterial populations related to sulfur and iron cycles, mineral and tuberculation with those identified in ALWC support the relevance of experimental simulation of tidal conditions in the management of steel corrosion exposed to harbor environments.

Volume 30, Issue 3, 2014 – Biofouling GBIF-2013-0190.R3
Date de Publication (en ligne) : 23 janvier 2014

Voir la publication sur Taylor & Francis Online

Auteur(s) : H. Gueuné, Ph. Refait, M. Jeannin, R. Sabot, L. Paugam, J.B. Memet et E. Malard

Résumé : Les infrastructures portuaires en acier au carbone subissent des dégradations liées à la corrosion par l’eau de mer. La corrosion marine des aciers est plutôt de nature généralisée mais des processus de corrosion localisée accélérés peuvent être induits par des microorganismes. Ces phénomènes sont regroupés sous le terme de corrosion influencée par les microorganismes. Une structure en acier au carbone située en mer Méditerranée dans des conditions de faible marnage ayant subi une corrosion localisée de type cratère (« chancre ») a éte étudiée. Des analyses physico-chimiques (diffraction des rayons X et Raman) et microbiologiques des dépôts recouvrant l’acier ont été réalisées pour tenter d’identifier l’origine des dégradations. Les résultats montrent que ces dépôts sont globalement constitués de produits de corrosion et de microorganismes pouvant influencer les mécanismes de corrosion classiquement retrouvés en milieu marin. Néanmoins, la présence locale d’akaganéite (β-FeO1−x(OH)1+xClx) dans les cratères, associée à une concentration importante en microorganismes acidogènes semble indiquer une accélération des processus de corrosion liée à une acidification locale par ces microorganismes.

Matériaux & Techniques 101, 502 (2013)
Date de Publication (en ligne) : 14 janvier 2014

Voir la publication sur Matériaux & Techniques

Résumé : Des coupons en aciers au carbone ont été exposés en zone de marnage dans deux sites portuaires (Grands Ports Maritimes du Havre et de Nantes-Saint Nazaire). La couche de produits de corrosion recouvrant les coupons après 6 mois, 12 mois et 7 ans d’exposition a été analysée en détail par diffraction des rayons X et µ-spectroscopie Raman. Les résultats obtenus aux temps courts (6 et 12 mois) mettent en évidence un processus général qui conduit principalement à la formation de magnétite Fe3O4, produit typique de la corrosion atmosphérique favorisé par les cycles humide/sec, et d’oxyhydroxydes ferriques FeOOH. La rouille verte sulfatée RV(SO42-), produit caractéristique de la corrosion marine des aciers, est néanmoins observée en fine couche à la surface du métal sous la magnétite. Pour des temps plus longs d’exposition (7 ans), deux types de comportement sont observés, l’un s’apparentant à la corrosion atmosphérique, l’autre s’apparentant à la corrosion en immersion continue dans l’eau de mer. Cette différenciation est probablement liée aux conditions de séchage des couches de produits de corrosion lors de la période d’émersion de l’acier. A ces deux comportements sont associées des vitesses de corrosion différentes (~0,09 mm/an dans le premier cas et ~0,05 mm/an dans le second cas).

Volume 101, 503, 2013
Date de Publication (en ligne) : 20 décembre 2013

Voir la publication sur Matériaux & Techniques

Auteur(s) : E. Malard, H. Gueuné, A. Fagot, A. Lemière, L. Sjogren, J. Tidblad, J. M. Sanchez de Amaya, G. Muijzer, F. Marty, L. Quillet, S. Paisse

Résumé : Some European port authorities are currently concerned by a localised and accelerated corrosion, called Accelerated Low Water Corrosion (ALWC) occurring on steel waterfront structures. High corrosion rates induced can shorten drastically service life of the structure or lead to failure. Solutions to mitigate this corrosion are available but maintenance of these structures still remains costly.
Previous studies showed that ALWC is microbiologically induced; however mechanisms and bacteria involved have not been entirely determined until now.
This project aims at developing diagnostic tools and a risk assessment method for industrial end users to predict and assess ALWC by using advanced molecular methods.

KI-NA-25904-EN-N

Voir la publication sur Bookshop Europa

Auteur(s) : Refait Ph. Jeannin M. Sabot R. Antony H. Pineau S.

Dans le cadre du programme de R&D CEMAR PC

Résumé : Carbon steel coupons were permanently exposed to seawater in the low water zone of two French harbors for 5 years before to be subjected to cathodic protection (potential about 0.95 V vs. Ag/AgCl/seawater) for 1 year. The application of cathodic polarization to the previously unprotected coupons induced the transformation of GR(SO2 4 ) into GR(CO2 3 ). Other coupons were permanently protected by cathodic protection during the 6 years immersion. A thin film of green rust and mackinawite was observed on the steel surface. This film was covered by a thicker layer of calcareous deposits. 2013 Elsevier Ltd. All rights reserved.

Corrosion Science 71 (2013) 32-36

Voir la publication sur Science Directe

Auteur(s) : Marty F, Ghiglione JF, Païssé S, Gueuné H, Quillet L, van Loosdrecht MC, Muyzer G.

Department of Biotechnology, Delft University of Technology, Delft, the Netherlands.

Résumé : Different DNA and RNA extraction approaches were evaluated and protocols optimized on in situ corrosion products from carbon steel in marine environments. Protocols adapted from the PowerSoil DNA/RNA Isolation methods resulted in the best nucleic acid (NA) extraction performances (ie combining high NA yield, quality, purity, representativeness of microbial community and processing time efficiency). The PowerSoil RNA Isolation Kit was the only method which resulted in amplifiable RNA of good quality (ie intact 16S/23S rRNA). Sample homogenization and hot chemical (SDS) cell lysis combined with mechanical (bead-beating) lysis in presence of a DNA competitor (skim milk) contributed to improving substantially (around 23 times) the DNA yield of the PowerSoil DNA Isolation Kit. Apart from presenting NA extraction strategies for optimizing extraction parameters with corrosion samples from carbon steel, this study proposes DNA and RNA extraction procedures suited for comparative molecular analysis of total and active fractions of bacterial communities associated with carbon steel corrosion events, thereby contributing to improved MIC diagnosis and control.

Voir la publication sur [PubMed – indexed for MEDLINE]

Auteur(s) : Païssé S, Ghiglione JF, Marty F, Abbas B, Gueuné H, Amaya JM, Muyzer G, Quillet L.

LU Microbiologie Environnementale et Biologie Evolutive-MEBE, Université de Rouen, UFR des Sciences, IRESE B, Place Emile Blondel, Mont-Saint-Aignan 76821, France.

Résumé : In the present study, investigations were conducted on natural corrosion deposits to better understand the role of sulfate-reducing bacteria (SRB) in the accelerated corrosion process of carbon steel sheet piles in port environments. We describe the abundance and diversity of total and metabolically active SRB within five natural corrosion deposits located within tidal or low water zone and showing either normal or accelerated corrosion. By using molecular techniques, such as quantitative real-time polymerase chain reaction, denaturing gel gradient electrophoresis, and sequence cloning based on 16S rRNA, dsrB genes, and their transcripts, we demonstrated a clear distinction between SRB population structure inhabiting normal or accelerated low-water corrosion deposits. Although SRB were present in both normal and accelerated low-water corrosion deposits, they dominated and were exclusively active in the inner and intermediate layers of accelerated corrosion deposits. We also highlighted that some of these SRB populations are specific to the accelerated low-water corrosion deposit environment in which they probably play a dominant role in the sulfured corrosion product enrichment.

Voir la publication sur PubMed – in process]

Auteur(s) : Hervé ANTONY, Émilie MALARD, Éliane SUTTER, T. T. Mai TRAN, Bernard TRIBOLLET, Marc JEANNIN, Philippe REFAIT, René SABOT

Résumé : L’exposition d’aciers à des conditions maritimes portuaires (immersion, marnage, éclaboussures…) conduit rapidement à la formation d’un dépôt sur la surface métallique Ce dépôt est constitué d’un mélange de produits de corrosion de l’acier et de composés minéraux et organiques. La présence de ces dépôts peut se révéler protectrice ou néfaste vis-à-vis des phénomènes de corrosion selon leurs caractéristiques (nature, répartition, conductivité, …).
Cette étude vise à améliorer les connaissances des propriétés d’interfaces acier/environnement des infrastructures métalliques portuaires afin d’optimiser la mise en place et le dimensionnement d’un système de protection cathodique. Ces travaux sont basés sur l’analyse des caractéristiques physico-chimiques et électrochimiques des dépôts formés sur des coupons d’acier au carbone exposés 6 à 7 ans en zone des basses eaux en conditions naturelles portuaires au sein des Grands Ports Maritime de Nantes-Saint-Nazaire et du Havre. Ces coupons ont été placés dans différentes conditions d’essais : sous protection cathodique permanente ou différée, à l’abandon ou sous rupture de protection.
Les résultats de ce travail de recherche a permis de mettre en évidence, quel que soit le site pilote (estuarien ou strictement maritime), la formation de produits de corrosion selon le mécanisme généralement attendu sur des coupons d’acier à l’abandon. La protection cathodique permet une diminution significative de la cinétique de corrosion. Elle ne modifie pas fondamentalement la nature des produits de corrosion mais favorise la formation d’un dépôt plus protecteur que celui obtenu à l’abandon.

Résumé : Ship’s ballast waters transport large numbers of organisms which may become invasive in coastal regions. One option to address this problem is the use of biocides as ballast water treatment (BWT). Ef?cacy and environmental acceptability of three commercial active substances (the BWT biocides Peraclean® Ocean and Seakleen®, and alkylamine-based biocide Mexel® 432/336) were tested against three bacteria species, two vegetative microalgae and one zooplanktonic larva, in 10 and 30 Practical Salinity Unit (PSU) waters. In both salinities, PeraClean® Ocean was the most effective biocide against bacteria causing N 90% mortality at 20 mg/l, compared with 50 mg/l for Mexel® 432/336 and N 500 mg/l for Seakleen®. Regarding zooplankton, Seakleen® was the most effective chemical causing 90% mortality in 24 h at concentrations b 6 mg/l (LC9024 h) in both salinities, compared with 23 and 26 mg/l for Mexel® 432/336 and 370 and 480 mg/l for PeraClean® Ocean in 10 and 30 PSU, respectively. Similar pattern of ef?cacy was obtained for microalgae in 30 PSU: effective concentrations inducing 50% growth inhibition in 4 days were ? 1.6 mg/l for Seakleen®, ? 10.1 mg/l for Mexel® 432/336 and ?30.9 mg/l for PeraClean® Ocean. Our work highlighted that treated waters displayed residual toxicity after 24 h still inducing mortality depending on the organism and biocide. However Mexel® 432/336 is the only biocide which had no impact on oyster larvae development at effective concentration. Altogether our data showed that Mexel® 432/336 was the only biocide displaying a broad spectrum ef?cacy in concentrations b 50 mg/l and not toxic for oyster larvae development at this concentration. However residual toxicity of treated waters for any organism should be taken into account in BWT systems utilising biocides.

No of Pages 9

Résumé : Accelerated corrosion phenomena of carbon steel constantly immersed in seawater could be simulated in situ via a galvanic coupling of samples with steel port structures. Three harbours located on different seas and various conditions of immersion were considered so as to study the eventual correlation between dissimilatory sulphite-reductase genes and suplhate-containing corrosion products. In each case, after 6 or 12 months, the rust layers proved to be made of an inner black layer, close to steel surface, and an orange outer layer. Scanning electron microscopy, chemical analyses by inductively coupled plasma/atomic emission spectroscopy, X-ray diffraction and micro-Raman spectroscopy were used to obtain a detailed characterisation of these layers. The inner one proved to be mainly composed of iron sulphides FeS and Fe(II-III) hydroxysulphate green rust GR(SO42-), the outer one one of Fe(III) oxyhydroxides, with lepido-sulphate reduction by micro-organisms, was applied for the first time to rust layers. This detection was positive in most cases, especially for the inner part of the rust layers. This demonstrates that sulphate reducing bacteria are associated to GR(SO42-) inside the rust layers, sulphate reducing bacteria and/or thiosulphate reducing bacteria. © 2007 Elsevier Ltd. All rights reserved.

50 (2008), p. 1099-1111

Résumé : Non disponible

October 2008, p. 2-6

Résumé : The oxidation and reduction of carbonate, GR(CO3), and sulphate, GR(SO4), green rusts (GR) have been studied through electrochemical techniques, electrochemical quartz crystal microbalance (EQCM), FTIR, XRD and SEM. The used samples were made of thin films electrodeposited on gold substrate. The results from the present work, from our previous studies and from literature were compiled in order to establish a general scheme for the formation and transformation pathways involving carbonate or sulphate green rusts. Depending on experimental conditions, two routes of redox transformations occur. The first one corresponds to reaction via solution and leads to the formation of ferric products such as goethite or lepidocrocite (oxidation) or to the release of FeII ions into the solution (reduction) with soluble FeII–FeIII complexes acting as intermediate species. The second way is solid-state reaction that involve conversion of lattice Fe2+ into Fe3+ and deprotonation of OH groups in octahedra sheets (solid-state oxidation) or conversion of lattice Fe3+ into Fe2+ and protonation of OH groups (solid-state reduction). The solid-state oxidation implies the complete transformation of GR(CO3) or GR(SO4) to ferric oxyhydroxycarbonate exGRc-Fe(III) or ferric oxyhydroxysulphate exGRs-Fe(III), for which the following formulas can be proposed, FeIII 6(OH)(12-2y)(O)(2+y)(H2O)(y)(CO3) or FeIII 6(OH)(12-2z)(O)(2+z)(H2O)(6+z)(SO4) with 0 <=y or z<=2. The solid-state reduction gives ferrous hydroxycarbonate exGRc-Fe(II) or ferrous hydroxysulphate exGRs-Fe(II), which may have the following chemical formulas, [FeII 6(OH)10(H2O)2]·[CO3, 2H2O] or [FeII 6(OH)10(H2O)2]·[SO4, 8H2O].

Volume 53, 2008, Pages 7146-7156

Résumé : Thin films of carbonate or sulphate green rusts were synthesised from potentiostatic oxidation of solutions containing ferrous species and bicarbonate or sulphate ions at slightly alkaline pHs and ambient temperature. The thin films were characterised by means of electrochemical quartz crystal microbalance, scanning electron microscopy, X-ray diffraction and infrared reflection–absorption spectroscopy. The composition of carbonate or sulphate green rusts was studied through chemical titration, inductively coupled plasma-optical emission spectroscopy (ICP-OES) and gravimetry and is as follows: [FeII (2R)FeIII 2(OH)(4R’2R’+6)(H2O)(2R’-2)]2R’+·[R’CO3, (2R-{3 or 4}R’ + 2)·H2O]2R’- and [FeII (2R)FeIII 2(OH)(4R?2R »+6)(H2O)(2R »-2)]2R »+·[R »SO4, (4R-4R’ + 4)·H2O]2R »- FeII/FeIII ratio R depends on the concentration of soluble ferrous species that are located at electrode surface during the potentiostatic synthesis and increases as the potential is made more negative. R-values are in the ?2–2.5 range for carbonate green rust, and in the ~2–2.2 range for sulphate green rust. The obtained R’- and R »-values are 1–1.3 and 1.1–1.4 for carbonate and sulphate green rusts, respectively. The present study excludes the existence of green rusts with FeII/FeIII ratio, R, lower than 2. The R-values lower than 2 that are found in some studies might relate to mixtures of the green rust and its solid-state oxidation product exGR-Fe(III) (ferric oxyhydroxycarbonate or ferric oxyhydroxysulphate) rather than to pure green rust.

Volume 53, 2008, Pages 7146-7156

Résumé : Seawater is a universal fluid – it is the medium where oceanographic moorings, ships, harbour installations and offshore platforms spend their life. Seawater is also widely used in industrial applications: for cooling and for use against fire in ships and platforms, and in coastal installations such as refineries, chemical/petrochemical plants, desalination plants and power stations. By nature, seawater is very corrosive to metallic materials; it contains, for example, dissolved oxygen, micro-organisms, and high concentrations of chloride ions and other chemical species deleterious to the integrity of metallic materials, such as hydrogen sulphide and ammonia compounds. Therefore, when designing any equipment or industrial plant that will be in contact with seawater, it is important to know about, and to take into account, the behaviour of metallic materials in seawater. It is also absolutely essential to evaluate the effects not only of corrosion, but also the environmental effects of measures taken to counteract it.

Vol. 15; No. 1, p. 38-43

Résumé : Several indoor atmospheric corrosion layers (0–800 years old) were selected from different localisations in France. Each sample was scrapped from its iron substrate. The resulting powder was mixed with graphite in appropriate proportions and the mixture was pressed onto a stainless steel grid to constitute a composite electrode. The electrochemical responses of the different samples were recorded under galvanostatic regulation, in a near-neutral pH-buffered NaCl solution at 25 °C. The E–t reduction curves allowed the determination of two characteristic parameters, E?/2, the potential value obtained at half the transition time, and Q?, the coulombic charge obtained at the end of the reduction. The diminution of E?/2 and Q? with the age of the corrosion layer showed that the “reduction reactivity” decreases with time, suggesting a progressive stabilisation of the corrosion layer. In a second part of the work, we synthesised several common ferric or ferrous/ferric products (goethite, lepidocrocite, magnetite, maghemite, ferrihydrite) and compared their reduction responses (product alone or mixture of 2 or 3 products) to those of corrosion samples.

Résumé : Ferric product powders were synthesised. The purity of each compound was controlled by FTIR and XRD analysis; the BET surface area and electrical conductivity were also reported. The galvanostatic electrochemical reduction of graphite/ferric product composite electrodes was investigated at 25 °C in mildly alkaline pH-buffered solutions containing chloride, sulphate or bicarbonate anions. The efficiency of the reduction process (FeIII-to-FeII reaction) was quantified by reporting the potential value obtained at half the transition time, Es/2, on the E–t transient, as a function of Qs, the coulombic charge obtained at the end of the reduction. The possibilities for a galvanic coupling to occur have been discussed based on the reduction efficiency plots and corrosion potential values of iron in the various media. © 2005 Elsevier Ltd. All rights reserved.

Volume 48, Issue 8, Août 2006, Pages 2050-2063

Résumé : Abstract : The electrochemical reduction of lepidocrocite ?-FeOOH was investigated at 25 °C in neutral or slightly alkaline solutions containing chloride, sulphate or bicarbonate anions by means of thin lepidocrocite film electrodeposited on inert gold substrate or graphite/lepidocrocite powder composite electrode. Electrochemical measurements were coupled to in situ electrochemical quartz crystal microbalance (EQCM) and ex situ SEM and FTIR analysis. The reduction of lepidocrocite occurs in all the electrolytes considered here. The initial reduction product is adsorbed ferrous ion, Feads2+. The desorption of Feads2+ is promoted as pH increases, leading to an increase of reduction depth. This promotion is related to the formation of secondary FeII-containing species, as revealed by SEM and FTIR. The comparison of ?-FeOOH reduction potentials and iron corrosion potentials let us state that the galvanic coupling is possible.

Volume 51, Issue 4, 1 November 2005, Pages 745-753

Résumé : Non disponible

N° 7-8-9 2004 p.38-43

Abstract : The deterioration of iron-based materials due to corrosion is a well-known problem. A variety of corrosion products can be formed depending on the species present in the medium (soil, water, etc.). Understanding the transformation pathways during the evolution of a corrosion layer is a hard challenge since it is difficult to clearly identify the contributions of each corrosion product. That is why the development of electrodes with only one iron corrosion product deposited as thin layers on inert substrates (gold, silver) presents many advantages to carry out electrochemical studies. In this way, the present paper reports successful electrochemical synthesis of thin layers deposited on inert substrates (gold, silver) of commonly occurring iron corrosion products as siderite, green rusts incorporating carbonate or sulphate anions, magnetite and goethite. The films are characterised by usual ex-situ techniques: FTIR, SEM, and XRD. The study of the electrochemical behaviour of thin films of green rust deposited on silver illustrates the potential application of such electrodes.

Volume 49, Issues 17-18, 30 July 2004, Pages 2891-2899

Résumé : Lepidocrocite thin films have been electrochemically synthesised on polycrystalline Au substrates following two ways, direct synthesis and synthesis via green rust (GR). The direct synthesis consists in oxidising Fe(II) species in a 0.4 M NaCl/0.02 M Met-Imidazole/0.01 M FeCl2 solution at pH 7.5. The synthesis via GR consists in converting a green rust thin film into lepidocrocite thin film by galvanostatic oxidation. The thin films have been characterised by means of electrochemical quartz crystal microbalance, scanning electron microscopy, X-ray diffraction and infrared reflection–absorption spectroscopy.

Volume 50, Issue 4, 15 December 2004, Pages 1015-1021

Abstract : Non disponible

Eurocorr, Nice, September 2004

Résumé : Non disponible

Abstract : Cathodic protection is widely used to prevent corrosion of steel constructions exposed to seawater. This protection causes a calcareous deposit as well as a biofilm formation. The Sulphate-Reducing Bacteria (SRB) and Thiosulphate-Reducing Bacteria (TRB) are involved in the steel biodegradation phenomena in marine environment. The surface colonization by these species under cathodic protection are described particularly for the TRB and with immersion periods of over 30 days. After a brief-review, preliminary studies explain the first results of our investigation in natural seawater and carbon steel during 4 to 8 weeks experiment. We have made experiments with natural strains of SRB/TRB, with monoculture of Desulfovibrio halophilus (SRB) and Dethiosulfovibrio peptidovorans (TRB), with potential a Cathodic Protection (CP) of –900 mV/SCE and –1000 mV/SCE and without CP. These results seem indicate that the effects of CP on the sulphide-producing bacteria metabolism is the reduction of their corrosive activity.

Proceedings p.169-178

Résumé : Green rusts are layered Fe(II)–Fe(III) hydroxy-salts that play an important role in iron corrosion, soil chemistry, and environmental engineering. Successful electrochemical depositions of thin layers of green rusts incorporating anions such as carbonate or chloride (GRs1) or sulphate (GR2) on gold substrate are presented. As far as we know, it is the first time that such synthesis has been reported. The thin layers of green rusts were characterized by ex situ methods such as XRD, SEM, EDS and FTIR. This new way of synthesis allowed us to get green rust particles with sizes significantly larger than those obtained from the ways reported until now.

Volume 5, Issue 3, March 2003, Pages 208-213

Résumé : Non disponible

N°9-10 2002, p.23-29