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Sample records for corrosion sous contrainte

  1. Stress corrosion cracking of Inconel in high temperature water; Corrosion fissurante sous contrainte de l'Inconel dans l'eau a haute temperature

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    Coriou,; Grall,; Gall, Le; Vettier, [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Some Inconel samples were subjected to hot water corrosion testing (350 deg. C), under stress slightly above the elastic limit. It has been observed that different types of alloys - with or without titanium - could suffer serious intergranular damage, including a complete rupture, within a three months period. In one case, we observed an unusual intergranular phenomenon which appeared quite different from common intergranular corrosion. (author) [French] Des essais de corrosion d'Inconel sont realises dans l'eau a 350 deg. C, et sous contrainte legerement superieure a la limite elastique. On constate que differentes varietes d'alliage avec ou sans titane donnent lieu a des accidents intergranulaires graves allant jusqu'a rupture complete en 3 mois. Dans un cas, on observe un phenomene intergranulaire particulier tres different de la corrosion intergranulaire classique. (auteur)

  2. Stress field determination in an alloy 600 stress corrosion crack specimen; Determination du champ de contraintes dans une eprouvette de corrosion sous contrainte de l`alliage 600

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    Rassineux, B.; Labbe, T.

    1995-05-01

    In the context of EDF studies on stress corrosion cracking rates in the Alloy 600 steam generators tubes, we studied the influence of strain hardened surface layers on the different stages of cracking for a tensile smooth specimen (TLT). The stress field was notably assessed to try and explain the slow/rapid-propagation change observed beyond the strain hardened layers. The main difficulty is to simulate in a finite element model the inner and outer surfaces of these strain hardened layers, produced by the final manufacturing stages of SG tubes which have not been heat treated. In the model, the strain hardening is introduced by simulating a multi-layer material. Residual stresses are simulated by an equivalent fictitious thermomechanical calculation, realigned with respect to X-ray measurements. The strain hardening introduction method was validated by an analytical calculation giving identical results. Stress field evolution induced by specimen tensile loading were studied using an elastoplastic 2D finite element calculations performed with the Aster Code. The stress profile obtained after load at 660 MPa shows no stress discontinuity at the boundary between the strain hardened layer and the rest of the tube. So we propose that a complementary calculation be performed, taking into account the multi-cracked state of the strain hardened zones by means of a damage variable. In fact, this state could induce stress redistribution in the un-cracked area, which would perhaps provide an explanation of the crack-ground rate change beyond the strain hardened zone. The calculations also evidence the harmful effects of plastic strains on a strain hardened layer due to the initial state of the tube (not heat-treated), to grit blasting or to shot peening. The initial compressive stress condition of this surface layer becomes, after plastic strain, a tensile stress condition. These results are confirmed by laboratory test. (author). 10 refs., 18 figs., 9 tabs., 2 appends.

  3. Quantitative characterization of initiation and propagation in stress corrosion cracking. An approach of a phenomenological model; Caracterisation quantitative de l`amorcage et de la propagation en corrosion sous contrainte. Approche d`une modelisation phenomenologique

    Energy Technology Data Exchange (ETDEWEB)

    Raquet, O

    1994-11-25

    A purely phenomenological study of stress corrosion cracking was performed using the couple Z2CN 18.10 (304L) austenitic stainless steel/boiling MgCl{sub 2} aqueous solution. The exploitation of the morphological information (shape of the cracks and size distribution) available after constant elongation rate tests led to the proposal of an analytical expression of the crack initiation and growth rates. This representation allowed to quantitatively characterize the influence of the applied strain rate as well as the effect of corrosion inhibitors on the crack initiation and propagation phases. It can be used in the search for the stress corrosion cracking mechanisms as a `riddle` for the determination of the rate controlling steps. As a matter of fact, no mechanistic hypothesis has been used for its development. (author).

  4. Study of alloy 600`S stress corrosion cracking mechanisms in high temperature water; Etude des mecanismes de corrosion sous contrainte de l`alliage 600 dans l`eau a haute temperature

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    Rios, R

    1994-06-01

    In order to better understand the mechanisms involved in Alloy 600`s stress corrosion cracking in PWR environment, laboratory tests were performed. The influence of parameters pertinent to the mechanisms was studies : hydrogen and oxygen overpressures, local chemical composition, microstructure. The results show that neither hydrogen nor dissolution/oxidation, despite their respective roles in the process, are sufficient to account for experimental facts. SEM observation of micro-cleavage facets on specimens` fracture surfaces leads to pay attention to a new mechanism of corrosion/plasticity interactions. (author). 113 refs., 73 figs., 15 tabs., 4 annexes.

  5. Embrittlement and anodic process in stress corrosion cracking: study of the influent micro-mechanical parameters; Fragilisation et processus anodiques en corrosion sous contrainte: etude des parametres micro-mecaniques influents

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    Tinnes, J.Ph

    2006-11-15

    We study the influence of local mechanical parameters on crack propagation in Stress Corrosion Cracking, at the scale of the microstructure. Two systems are compared: the CuAl{sub 9}Ni{sub 3}Fe{sub 2} copper-aluminium alloy in synthetic sea water under cathodic polarization, where the crack propagation mechanism is related to strain-assisted anodic dissolution, and the 316L austenitic stainless steel in MgCl{sub 2} solution, where embrittlement mechanisms related to hydrogen effects prevail. We use micro-notched tensile specimen that allow to study isolated short cracks. These experiments are modelled by means of finite elements calculations, and further characterized by Electron Back scattered Diffraction (EBSD) in the case of the 316L alloy. In terms of the local mechanical parameters that control propagation, fundamental differences are outlined between the two systems. They are discussed from the viewpoint of the available models of Stress Corrosion Cracking. (author)

  6. Stress corrosion cracking in the vessel closure head penetrations of French PWR`s; Fissuration par corrosion sous contrainte de penetrations de couvercle de cuve de reacteur nucleaire francais a eau pressurisee

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    Buisine, D.; Cattant, F.; Champredonde, J.; Pichon, C.; Benhamou, C.; Gelpi, A.; Vaindirlis, M.

    1994-01-01

    During a hydrotest in September 1991, part of the statutory decennial in-service inspection, a leak was detected on the vessel head of Bugey 3, which is one of the first 900 MW 3-loop PWR`s in France. This leak was due to a cracked penetration used for a control rod drive mechanism. The investigations performed identified Primary Stress Corrosion Cracking of Alloy 600 as being the origin of this degradation. So a lot of the same design PWR`s are a concern due to this generic problem. In this case, PWSCC was linked to: - hot temperature of the vessel head; - high residual stresses due to the welding process between peripherical penetrations and the vessel head; - sensitivity of forged Alloy 600 used for penetration manufacturing. This following paper will present the cracked analysis based, in particular, on the main results obtained in France on each of these items. These results come from the operating experience, the destructive examinations and the programs which are running on stress analysis and metallurgical characterizations. (authors). 9 figs., 2 tabs.

  7. Metallurgical and mechanical parameters controlling alloy 718 stress corrosion cracking resistance in PWR primary water; Facteurs metallurgiques et mecaniques controlant l'amorcage de defauts de corrosion sous contrainte dans l'alliage 718 en milieu primaire des reacteurs a eau sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Deleume, J

    2007-11-15

    Improving the performance and reliability of the fuel assemblies of the pressurized water reactors requires having a perfect knowledge of the operating margins of both the components and the materials. The choice of alloy 718 as reference material for this study is justified by the industrial will to identify the first order parameters controlling the excellent resistance of this alloy to Stress Corrosion Cracking (SCC). For this purpose, a specific slow strain rate (SSR) crack initiation test using tensile specimen with a V-shaped hump in the middle of the gauge length was developed and modeled. The selectivity of such SSR tests in simulated PWR primary water at 350 C was clearly established by characterizing the SCC resistance of nine alloy 718 thin strip heats. Regardless of their origin and in spite of a similar thermo-mechanical history, they did not exhibit the same susceptibility to SCC crack initiation. All the characterized alloy 718 heats develop oxide scale of similar nature for various exposure times to PWR primary medium in the temperature range [320 C - 360 C]. {delta} phase precipitation has no impact on alloy 718 SCC initiation behavior when exposed to PWR primary water, contrary to interstitial contents and the triggering of plastic instabilities (PLC phenomenon). (author)

  8. Jules Verne : un processus d’écriture sous contraintes

    OpenAIRE

    Scheinhardt, Philippe

    2013-01-01

    Devenu célèbre, Jules Verne reçoit souvent la visite de journalistes qui l’interrogent aussi bien sur sa vie que sur son œuvre. De ces entretiens, il ressort que l’écrivain respecte comme tant d’autres des rites de création : habitudes de documentation, méthode de genèse littéraire. Ces rites, en écho à la contrainte externe du programme encyclopédique des Voyages extraordinaires, remplissent la fonction de contraintes internes au service de l’acte créateur. Ils renseignent sur les diverses p...

  9. Stress corrosion of austenitic steels mono and polycrystals in Mg Cl{sub 2} medium: micro fractography and study of behaviour improvements; Corrosion sous contrainte de mono et polycristaux d`aciers inoxydables austenitiques en milieu MgCI{sub 2}: analyse microfractographique et recherche d`ameliorations du comportement

    Energy Technology Data Exchange (ETDEWEB)

    Chambreuil-Paret, A

    1997-09-19

    The austenitic steels in a hot chlorinated medium present a rupture which is macroscopically fragile, discontinuous and formed with crystallographic facets. The interpretation of these facies crystallographic character is a key for the understanding of the stress corrosion damages. The first aim of this work is then to study into details the micro fractography of 316 L steels mono and polycrystals. Two types of rupture are observed: a very fragile rupture which stresses on the possibility of the interatomic bonds weakening by the corrosive medium Mg Cl{sub 2} and a discontinuous rupture (at the micron scale) on the sliding planes which is in good agreement with the corrosion enhanced plasticity model. The second aim of this work is to search for controlling the stress corrosion by the mean of a pre-strain hardening. Two types of pre-strain hardening have been tested. A pre-strain hardening with a monotonic strain is negative. Indeed, the first cracks starts very early and the cracks propagation velocity is increased. This is explained by the corrosion enhanced plasticity model through the intensifying of the local corrosion-deformation interactions. On the other hand, a cyclic pre-strain hardening is particularly favourable. The first micro strains starts later and the strain on breaking point levels are increased. The delay of the starting of the first strains is explained by a surface distortion structure which is very homogeneous. At last, the dislocations structure created in fatigue at saturation is a planar structure of low energy which reduces the corrosion-deformation interactions, source of micro strains. (O.M.) 139 refs.

  10. TEM characterisation of stress corrosion cracks in nickel based alloys: effect of chromium content and chemistry of environment; Caracterisation par MET de fissures de corrosion sous contrainte d'alliages a base de nickel: influence de la teneur en chrome et de la chimie du milieu

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    Delabrouille, F

    2004-11-15

    Stress corrosion cracking (SCC) is a damaging mode of alloys used in pressurized water reactors, particularly of nickel based alloys constituting the vapour generator tubes. Cracks appear on both primary and secondary sides of the tubes, and more frequently in locations where the environment is not well defined. SCC sensitivity of nickel based alloys depends of their chromium content, which lead to the replacement of alloy 600 (15 % Cr) by alloy 690 (30 % Cr) but this phenomenon is not yet very well understood. The goal of this thesis is two fold: i) observe the effect of chromium content on corrosion and ii) characterize the effect of environment on the damaging process of GV tubes. For this purpose, one industrial tube and several synthetic alloys - with controlled chromium content - have been studied. Various characterisation techniques were used to study the corrosion products on the surface and within the SCC cracks: SIMS; TEM - FEG: thin foil preparation, HAADF, EELS, EDX. The effect of chromium content and surface preparation on the generalised corrosion was evidenced for synthetic alloys. Moreover, we observed the penetration of oxygen along triple junctions of grain boundaries few micrometers under the free surface. SCC tests show the positive effect of chromium for contents varying from 5 to 30 % wt. Plastic deformation induces a modification of the structure, and thus of the protective character, of the internal chromium rich oxide layer. SCC cracks which developed in different chemical environments were characterised by TEM. The oxides which are formed within the cracks are different from what is observed on the free surface, which reveals a modification of medium and electrochemical conditions in the crack. Finally we were able to evidence some structural characteristics of the corrosion products (in the cracks and on the surface) which turn to be a signature of the chemical environment. (author)

  11. TEM characterisation of stress corrosion cracks in nickel based alloys: effect of chromium content and chemistry of environment; Caracterisation par MET de fissures de corrosion sous contrainte d'alliages a base de nickel: influence de la teneur en chrome et de la chimie du milieu

    Energy Technology Data Exchange (ETDEWEB)

    Delabrouille, F

    2004-11-15

    Stress corrosion cracking (SCC) is a damaging mode of alloys used in pressurized water reactors, particularly of nickel based alloys constituting the vapour generator tubes. Cracks appear on both primary and secondary sides of the tubes, and more frequently in locations where the environment is not well defined. SCC sensitivity of nickel based alloys depends of their chromium content, which lead to the replacement of alloy 600 (15 % Cr) by alloy 690 (30 % Cr) but this phenomenon is not yet very well understood. The goal of this thesis is two fold: i) observe the effect of chromium content on corrosion and ii) characterize the effect of environment on the damaging process of GV tubes. For this purpose, one industrial tube and several synthetic alloys - with controlled chromium content - have been studied. Various characterisation techniques were used to study the corrosion products on the surface and within the SCC cracks: SIMS; TEM - FEG: thin foil preparation, HAADF, EELS, EDX. The effect of chromium content and surface preparation on the generalised corrosion was evidenced for synthetic alloys. Moreover, we observed the penetration of oxygen along triple junctions of grain boundaries few micrometers under the free surface. SCC tests show the positive effect of chromium for contents varying from 5 to 30 % wt. Plastic deformation induces a modification of the structure, and thus of the protective character, of the internal chromium rich oxide layer. SCC cracks which developed in different chemical environments were characterised by TEM. The oxides which are formed within the cracks are different from what is observed on the free surface, which reveals a modification of medium and electrochemical conditions in the crack. Finally we were able to evidence some structural characteristics of the corrosion products (in the cracks and on the surface) which turn to be a signature of the chemical environment. (author)

  12. Part of the hydrogen in the intergranular crack by stress corrosion in primary circuit for the 600 and 690 nickel base alloys; Role de l'hydrogene dans le mecanisme de fissuration intergranulaire par corrosion sous contrainte en milieu primaire des alliages base nickel 600 et 690

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    Odemer, G.; Coudurier, A.; Jambon, F.; Chene, J. [CEA Saclay, Dept. de Physico-Chimie (DPC/SCCME/LECA), 91 - Gif sur Yvette (France); Odemer, G.; Coudurier, A.; Chene, J. [Evry Univ., UMR 8587 CNRS / CEA, LAMBE, 91 (France)

    2007-07-01

    The aim of this study is, in a first part, to characterize the hydrogen embrittlement sensitivity of the 600 and 690 based alloys in order to better understand the hydrogen role in the stress corrosion mechanism which appears in theses alloys in the primary circuit of the PWR type reactors. The authors studies how the hydrogen embrittlement is resulting from an interaction between the hydrogen and the plastic deformation. (A.L.B.)

  13. Influence of localized deformation on A-286 austenitic stainless steel stress corrosion cracking in PWR primary water; Influence de la localisation de la deformation sur la corrosion sous contrainte de l'acier inoxydable austenitique A-286 en milieu primaire des REP

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    Savoie, M

    2007-01-15

    Irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steels is known to be a critical issue for structural components of nuclear reactor cores. The deformation of irradiated austenitic stainless steels is extremely heterogeneous and localized in deformation bands that may play a significant role in IASCC. In this study, an original approach is proposed to determine the influence of localized deformation on austenitic stainless steels SCC in simulated PWR primary water. The approach consists in (i) performing low cycle fatigue tests on austenitic stainless steel A-286 strengthened by {gamma}' precipitates Ni{sub 3}(Ti,Al) in order to shear and dissolve the precipitates in intense slip bands, leading to a localization of the deformation within and in (ii) assessing the influence of these {gamma}'-free localized deformation bands on A-286 SCC by means of comparative CERT tests performed on specimens with similar yield strength, containing or not {gamma}'-free localized deformation bands. Results show that strain localization significantly promotes A-286 SCC in simulated PWR primary water at 320 and 360 C. Moreover, A-286 is a precipitation-hardening austenitic stainless steel used for applications in light water reactors. The second objective of this work is to gain insights into the influence of heat treatment and metallurgical structure on A-286 SCC susceptibility in PWR primary water. The results obtained demonstrate a strong correlation between yield strength and SCC susceptibility of A-286 in PWR primary water at 320 and 360 C. (author)

  14. Evolution de la perméabilité d'agrégats de sels sous contrainte liée à des circulations de fluides : dissolution, colmatage, déformation

    OpenAIRE

    Chen , Tao

    1994-01-01

    Le but de ce travail est d'étudier l'évolution de la perméabilité d'agrégats de sels sous contrainte lorsque les fluides circulant dans ces agrégats peuvent réagir avec le solide par des dissolutions et/ou des colmatages. Des essais de circulation de divers fluides à travers des échantillons de briques de sels sous contrainte ont permis de suivre l'évolution de la composition des fluides en cours d'essai. L'évolution des matériaux a été aussi caractérisée en cours d'essai (mesure de vitesse a...

  15. Méthode multi-échelle pour la modélisation du flambage des tôles minces sous contraintes résiduelles - Application au laminage

    OpenAIRE

    Nakhoul , Rebecca; Montmitonnet , Pierre; Potier-Ferry , Michel

    2013-01-01

    National audience; Dans le laminage à froid, l'apparition d'une distribution hétérogène de contraintes résiduelles peut engendrer le flambage de la tôle laminée, entraînant un " défaut de planéité ". L'objectif est de définir un modèle macroscopique simple décrivant les modes et amplitudes de flambage d'une tôle sous l'effet des contraintes résiduelles issues du laminage. Le présent article présente une nouvelle méthode bi-échelle [1,2] comme une alternative du modèle de flambage développé da...

  16. Tractographie globale sous contraintes anatomiques

    OpenAIRE

    Teillac , Achille

    2017-01-01

    This work aims at developing a method inferring white matter fibers reconstructed using a global spin-glass approach constrained by anatomical prior knowledge. Unlike usual methods building fibers independently from one another, our markovian approach reconstructs the whole tractogram in an unique process by minimizing the global energy depending on the spin glass configuration (position, orientation, length and connection(s)) and the match with the local diffusion process in order to increas...

  17. Intergranular Pressure Solution in Nacl: Grain-To-Grain Contact Experiments under the Optical Microscope Dissolution sous contrainte dans NaCl : expériences de contact grain à grain sous microscope optique

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    Spiers C. J.

    2006-12-01

    effective diffusivity varying with contact force and on-going convergence. The results agree broadly with those of previous compaction creep experiments performed using wet halite powder. Discrepancies with other workers results for single-contact dissolution experiments can be explained in terms of differences in experimental configuration and competition between driving forces. La dissolution sous contrainte (IPS - Intergranular Pressure Solution représente un mécanisme de lithification, de compaction et de déformation à l'échelle géologique pour une large gamme de roches. Les études expérimentales d'IPS réalisées sur des agrégats de quartz n'ont pas été couronnées de succès en raison d'un taux faible d'IPS, et les expériences IPS réalisées en utilisant une halite saturée comme analogue de roche (Spiers et Schutjens, 1990 ; Hickman et Evans, 1991 ont laissé des incertitudes quant au détail des mécanismes IPS et à la structure/saturation au contact du grain dans ce matériau. La présente étude fait état de quatre expériences de dissolution de contact réalisées sous microscope optique afin d'étudier le mécanisme et la cinétique de l'IPS pour des contacts simples halite/halite et halite/verre, chargés en eau salée (température ambiante. Des forces normales de contact dans la gamme de 1,0 à 2,6 N ont été appliquées en présence d'eau salée saturée en NaCl, induisant des pressions de 0,8 à 7,4 MPa. Des pertes de masse et des convergences - fonction du temps - ont été observées pour tous les contacts. Dans tous les cas, le fait de charger le contact (ou d'augmenter la charge sur le contact a conduit à la formation immédiate d'une morphologie de contact rugueuse, composée d'un motif d'îles et de canaux, contrôlé par des caractéristiques cristallographiques, à l'échelle de quelques microns. Cette microstructure non équilibrée a évolué dans le temps vers une face de contact optiquement plate. Le processus de convergence

  18. Contribution of the low cycle fatigue on ultra high purity Ni-Cr-Fe alloys and on Ni monocrystals to the understanding of the hydrogen role in stress corrosion cracking for the alloys 600 and 690; Apport de la fatigue oligocyclique sur alliages Ni-Cr-Fe d'ultra haute purete et sur monocristaux de Ni a la comprehension sous contrainte des alliages 600 et 69O

    Energy Technology Data Exchange (ETDEWEB)

    Renaudot, N

    1999-06-01

    We discuss the role of hydrogen in cracking of Ni base alloys used for pressurised water reactor (PWR) primary tubes (alloy 600 and 690). Cracking can be explained by a Stress Corrosion Cracking (SCC) phenomenon. For this purpose, Low cycle fatigue (R = - 1) under cathodic charging at room temperature is conducted to study hydrogen effects on propagation of cracks mechanically initiated by the formation of Persistent Slip Bands (PSB). Low cycle fatigue on Ultra High Purity specimens (Ni, alloy 600 and 690) reveals the very important hydrogen effect on crack propagation rate, whatever the Cr content in the Ni base alloy. If Cr seems to have an effect over-hydrogen penetration in specimens (by a protective film formation), it have no beneficial effect when hydrogen have diffused ahead of a crack tip. Propagation rates (transgranular or intergranular) are highly increased, no matter of the absence of impurities like sulphur. Then, in PWR, the difference in the behaviour of alloy 600 and 690 could be due to a slower microcrack propagation rate for alloy 690. Protective films could play an important role in this difference, which is to study. Low cycle fatigue on Ni single crystals oriented for single slip shows, for the first time on bulk specimen, a macroscopic softening which can be explained. by hydrogen-dislocation interactions. Moreover, a simple quantitative model based on these interactions results in the same softening as the one observed experimentally. These results allow to validate experimentally one of the most important steps in the 'Corrosion Enhanced Plasticity (CEP) model', i.e. the softening ahead of a stress corrosion crack tip by hydrogen dislocation interactions. This is of importance because this model can explain cracking in numerous FCC materials-environment couple. (author)

  19. Texturation à froid sous contraintes triaxiales de phase à haute T_c de Bi(Pb)SrCaCuO préréagie

    Science.gov (United States)

    Langlois, P.; Massat, H.; Suryanarayanan, R.

    1994-11-01

    The alignment of grains in isostatically precompacted samples of prereacted Bi{1,8}Pb{0,4}Sr{2,0}Ca{2,2}Cu{3,0}O{10,3 + x} powder has been achieved by compressive plastic deformation under isostatic pressure at room temperature. Isostatic pressures were in the range 0.1 to 1 GPa and deformation rates were led up to 57 %. Prior to sintering, X-ray diffraction measurements corroborate an expected high- T_c phase purity of nearly 85 % and indicate that the as-deformed samples have been textured with the (c-axes parallel to the pressing direction whilst a.c. susceptibility measurements ascertain a high transition temperature around 107 K. Intergranular connection does not occur until sintering at 850 ^{circ}C for 80 h and measurements indicate then that the texture has been retained. Superconducting properties themselves show sensitivity to texture through anisotropy-related distinctive irreversibility lines. L'alignement de grains de poudre Bi{1,8}Pb{0,4}Sr{2,0}Ca{2,2}Cu{3,0}O{10,3 + x} préréagie a été réalisé par déformation plastique à température ambiante d'échantillons précompactés isostatiquement et comprimés sous pression isostatique, la gamme des pressions isostatiques allant de 0,1 à 1 GPa et les taux de déformation atteignant 57 %. Les mesures de diffraction de rayons X corroborent la pureté de phase à haute T_c proche de 85 % attendue et indiquent que les échantillons ainsi déformés ont été texturés avec les plans ab perpendiculaires à la direction de compression. Les mesures de susceptibilité alternative avèrent une température élevée de transition à environ 107 K mais la connexion intergranulaire n'est assurée qu'après un frittage à 850 ^{circ}C pendant 80 h dont on vérifie qu'il conserve la texture. Enfin, la sensibilité des propriétés supraconductrices à la texturation est évaluée par le biais de lignes d'irréversibilité distinctes en fonction de l'anisotropie.

  20. La contrainte client

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    Guillaume Tiffon

    2011-04-01

    Full Text Available Cet article montre que le contact client a beau être ambivalent, dans la mesure où il est à la fois source de contrainte et de reconnaissance, dans certains cas, comme celui des caissières, il constitue avant tout une contrainte, en ce que les clients contrôlent le travail qui s’opère « sous leurs yeux », tandis que, dans d’autres cas, comme celui des kinésithérapeutes, il contribue avant tout à donner du sens au travail et, par là, à susciter l’engagement des travailleurs. L’article souligne ainsi combien la contrainte client revêt des modalités différentes selon la configuration, spatiale et temporelle, dans laquelle se déroule la relation de service, et le différentiel de compétences entre les protagonistes engagés dans cette relation.The client constraint. A comparative analysis of cashiers and physiotherapistsThis article shows that despite the ambivalence of client contact, insofar as it is both a source of constraint and recognition, in some cases, as the ones of cashiers, it isprimarily a constraint: clients control the work that takes place “before their eyes”, whereas in other cases – as in the ones of physiotherapists – it contributes to give meaning to work and, thereby, to arouse the commitment of workers. The article highlights how the client constraint takes on different forms depending on thespatial and temporal configuration where the service relation runs, and the skills differential between the protagonists involved in this relation.El apremio de los clientes. Análisis comparativo entre las cajeras de supermercado y los kinesiterapeutasEn este artículo se demuestra que aunque el contacto con los clientes puede ser percibido como agradable, en realidad en la mayoría de los casos el cliente es percibido como un peso puesto que estos « controlan » visualmente el trabajo de las cajeras mientras que en otras profesiones como es el caso de los kinesiterapeutas la presencia del paciente

  1. Analysis of stress intensity factors for a new mechanical corrosion specimen; Analyse du facteur d`intensite de contrainte pour une nouvelle eprouvette de mecanique corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Rassineux, B; Crouzet, D; Le Hong, S

    1996-03-01

    Electricite de France is conducting a research program to determine corrosion cracking rates in the steam generators Alloy 600 tubes of the primary system. The objective is to correlate the cracking rates with the specimen stress intensity factor K{sub I}. One of the samples selected for the purpose of this study is the longitudinal notched specimen TEL (TEL: ``Tubulaire a Entailles Longitudinales``). This paper presents the analysis of the stress intensity factor and its experimental validation. The stress intensity factor has been evaluated for different loads using 3D finite element calculations with the Hellen-Parks and G({theta}) methods. Both crack initiation and propagation are considered. As an assessment of the method, the numerical simulations are in good agreement with the fatigue crack growth rates measured experimentally for TEL and compact tension (CT) specimens. (authors). 8 refs., 6 figs., 2 tabs.

  2. Some problems on the aqueous corrosion of structural materials in nuclear engineering; Problemes de corrosion aqueuse de materiaux de structure dans les constructions nucleaires

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    Coriou, H; Grall, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    The purpose of this report is to give a comprehensive view of some aqueous corrosion studies which have been carried out with various materials for utilization either in nuclear reactors or in irradiated fuel treatment plants. The various subjects are listed below. Austenitic Fe-Ni-Cr alloys: the behaviour of austenitic Fe-Ni-Cr alloys in nitric medium and in the presence of hexavalent chromium; the stress corrosion of austenitic alloys in alkaline media at high temperatures; the stress corrosion of austenitic Fe-Ni-Cr alloys in 650 C steam. Ferritic steels: corrosion of low alloy steels in water at 25 and 360 C; zirconium alloys; the behaviour of ultrapure zirconium in water and steam at high temperature. (authors) [French] On presente un ensemble d'etudes de corrosion en milieu aqueux effectuees sur des materiaux utilises, soit dans la construction des reacteurs soit pour la realisation des usines de traitement des combustibles irradies. Les differents sujets etudies sont les suivants. Les alliages austenitiques Fer-Nickel-Chrome: comportement d'alliages austenitiques fer-nickel-chrome en milieu nitrique en presence de chrome hexavalent; Corrosion sous contrainte d'alliages austenitiques dans les milieux alcalins a haute temperature; Corrosion sous contrainte dans la vapeur a 650 C d'alliages austenitiques fer-nickel-chrome. Les aciers ferritiques; Corrosion d'aciers faiblement allies dans l'eau a 25 et 360 C; le zirconium et ses alliages; Comportement du zirconium tres pur dans l'eau et la vapeur a haute temperature. (auteurs)

  3. Les objets sous contrainte. Gages, saisies, confiscation, vol, pillage, recel…

    Directory of Open Access Journals (Sweden)

    Laurent Feller

    2009-09-01

    Full Text Available Cette table ronde s’inscrit dans le cadre d’une réflexion menée sur la valeur des choses au Moyen Âge, c’est-à-dire sur les conditions empiriques et théoriques de l’évaluation ; un groupe de travail conjoint du LAMOP (UMR 8589, Paris 1-CNRS et du CSIC de Madrid organise une série de tables rondes. La première s’est tenue à Madrid en novembre 2008 et a eu comme thème : « Circulation et remploi des objets au Moyen Âge ».Les objets circulent parfois malgré la volonté de leurs propriétaires, en ...

  4. Towards a quantification of stress corrosion mechanisms: numerical simulations of hydrogen-dislocations at the very crack tip; Vers une quantification des mecanismes de corrosion sous contrainte: simulations numeriques des interactions hydrogene-dislocations en pointe de fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chateau, J.P

    1999-01-05

    We discuss the respective roles played by anodic dissolution and hydrogen in SCC mechanisms of f.c.c. materials, by studying the fracture of copper in nitrite for which we compare the results with that previously obtained in 316L steel in hot chloride. It is surprising to note that even the crystallographies at the scale of the micron are different, the macroscopic inclination of the fracture surfaces are the same. In the case of 316L steel, the formation of strong pile-ups in the presence of hydrogen leads to a zigzag fracture along alternated slip planes in the most general case. In the absence of hydrogen, as in copper, this mechanism effectively disappears. Furthermore, numerical simulations of crack shielding by dislocations emitted on one plane predict the macroscopic inclination. It shows that it is due to the mere dissolution which confines slip activity at the very crack tip in f.c.c. materials. In order to quantify the mechanism involved in 316L steel, we developed simulations which numerically solve the coupled diffusion and elasticity equations for hydrogen in the presence of a crack and shielding dislocations. They reproduce the mechanisms of hydrogen segregation on edge dislocations and of a localised softening effect by decreasing pair interactions. These mechanisms lead to i) a localisation of hydrogen embrittlement along the activated slip planes, ii) an increase of the dislocation density in pile-ups, and iii) a decrease of the cross slip probability. These three factors enhance micro-fracture at the head of a pile-up, which is responsible of thezigzag fracture. Introducing the free surface effects for hydrogen, we point out a new mechanism: the inhibition of dislocation sources at the crack tip, which is relevant with the brittle fracture surfaces observed in some cases in 316L steel. The quantification of these different mechanisms allows to give a relation between the local fracture possibility and the macroscopic parameters. A general law for softening is proposed, and we show that micro-fracture occurs for realistic values of three key parameters: hydrogen concentration, decrease of k{sub lc} and obstacle resistance. (author)

  5. Etude de la propagation sous critique dans les fibres de verre par relaxation de la charge

    OpenAIRE

    R'Mili , M.; Godin , N.; Lamon , J.

    2011-01-01

    International audience; Plusieurs fibres inorganiques de type verre ou céramique (à base de carbure de silicium) sont très sensibles à la propagation sous critique de fissures, activée chimiquement ou thermiquement. Dans ce cas la rupture survient d'une façon prématurée à un niveau de contrainte relativement bas comparé à la contrainte de rupture. Cet article propose une approche statistique de la rupture en fatigue statique fondée sur l'analyse de la rupture des fibres dans une mèche sollici...

  6. Atmospheric corrosion of uranium-carbon alloys; Corrosion atmospherique des alliages uranium-carbone

    Energy Technology Data Exchange (ETDEWEB)

    Rousset, P; Accary, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    The authors study the corrosion of uranium-carbon alloys having compositions close to that of the mono-carbide; they show that the extent of the observed corrosion effects increases with the water vapour content of the surrounding gas and they conclude that the atmospheric corrosion of these alloys is due essentially to the humidity of the air, the effect of the oxygen being very slight at room temperature. They show that the optimum conditions for preserving U-C alloys are either a vacuum or a perfectly dry argon atmosphere. The authors have also established that the type of corrosion involved is a corrosion which 'cracks under stress' and is transgranular (it can also be intergranular in the case of sub-stoichiometric alloys). They propose, finally, two hypotheses for explaining this mechanism, one of which is illustrated by the existence, at the fissure interface, of corrosion products which can play the role of 'corners' in the mono-carbide grains. (authors) [French] Les auteurs etudient la corrosion des alliages uranium-carbone de composition voisine du monocarbure; ils montrent que l'importance des effets de la corrosion observee augmente avec la teneur en vapeur d'eau du milieu gazeux ambiant et concluent que la corrosion atmospherique de ces alliages est due essentiellement a l'humidite de l'air, l'action de l'oxygene de l'air etant tres faible a la temperature ambiante. Ils indiquent que les conditions optimales de conservation des alliages U-C sont le vide ou une atmosphere d'argon parfaitement desseches. D'autre part, les auteurs etablissent que le type de corrosion mis en jeu est une corrosion 'fissurante sous contrainte', transgranulaire (pouvant egalement etre intergranulaire dans le cas d'alliages sous-stoechiometriques). Ils proposent enfin deux hypotheses pour rendre compte de ce mecanisme, dont l'une est illustree par la mise en evidence, a l'interface des fissures, de produits de corrosion pouvant jouer le role de 'coins' dans les grains de

  7. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  8. Évolution des contraintes résiduelles dans la couche de diffusion d’un acier modèle Fe-Cr-C nitruré

    DEFF Research Database (Denmark)

    Jegou, Sébastien; Barrallier, Laurent; Somers, Marcel A. J.

    2011-01-01

    Limiter la fatigue et la corrosion des pièces est possible grâce à une nitruration. Des contraintes résiduelles en découlent. Le rôle de la diffusion du carbone sur le développement de ces contraintes a été étudié sur un acier modèle Fe-3%m.Cr-0.35%m.C.......Limiter la fatigue et la corrosion des pièces est possible grâce à une nitruration. Des contraintes résiduelles en découlent. Le rôle de la diffusion du carbone sur le développement de ces contraintes a été étudié sur un acier modèle Fe-3%m.Cr-0.35%m.C....

  9. Le sous-titrage : une pratique à la marge de la traduction

    Directory of Open Access Journals (Sweden)

    Dumas, Louise

    2014-12-01

    Full Text Available Le sous-titre interlinguistique est un objet difficile à appréhender théoriquement. S'il permet d'aller d'une langue à une autre, il implique aussi un passage de l'écoute à la lecture et du cinéma à l'écriture. Le caractère interlinguistique est souvent mis en avant pour amener à considérer le sous-titrage comme une traduction. Sa complexité médiologique suggère toutefois qu'il est plus qu'une traduction. En même temps, les fortes contraintes (exigence de brièveté, de lisibilité, de cohérence avec l'image cinématographique auxquelles il est soumis font qu'il est moins qu'une traduction – moins exact, moins long, moins « équivalent » au texte original. Le présent travail se propose de réfléchir de manière théorique aux rapports entre sous-titrage et traduction. Pour ce faire, nous confronterons le sous-titrage aux concepts fondamentaux de la traductologie. Premièrement, le passage de l'oral à l'écrit opéré dans les sous-titres est intimement lié à la distinction traductologique entre traduction et interprétariat. Pour pouvoir condenser les dialogues, résumer leur contenu, le sous-titreur est amené à les interpréter, ce qui permet de souligner l'étroite parenté entre traduction, interprétariat et interprétation. Deuxièmement, les fortes contraintes auxquelles sont soumis les sous-titres invitent à s'interroger sur la notion d'équivalence qui se trouve normalement au principe de toute traduction. Toutes les théories traductologiques insistent sur le fait qu'une équivalence n'est jamais parfaite et que le traducteur privilégie certains niveaux d'équivalence : en poussant à l'extrême cette dynamique de sélection constitutive de l'équivalence, on peut considérer que les sous-titres sont équivalents aux dialogues. En tant que cas limite, le sous-titrage permet de tester les concepts fondamentaux de la traductologie et de définir leurs limites.

  10. New facts in mechanism, development and inspection of stress corrosion vulnerability in gas trunk lines; Nouveaux elements dans le mecanisme, le developpement et le diagnostic de la vulnerabilite a la corrosion sous tension des conduites de gaz principales

    Energy Technology Data Exchange (ETDEWEB)

    Ott, K. [Tyumentransgaz, (Russian Federation)

    2000-07-01

    Stress corrosion cracking (SCC) of the buried pipelines has been acknowledged a serious problem long ago. The author's researches (1) for a long period of time have established that SCC occurrence in pipe metal is affected by a combination of three factors: - Metal quality - availability of structural reasons contributing to occurrence and development of original microcracks; - Appropriate level of active stresses (considering inner residual stresses in the structure of metal), exceeding threshold level for occurrence and development of microcracks at rated operating conditions of the pipeline; - Availability of corrosive environment saturated with soil microorganisms, its access to the metal surface and interaction of the environment and metal structure. Operating failure mechanism and kinetics were proposed for buried pipelines - they give insight into, and enable to classify SCC cases as a local bio-corrosion process occurring in abnormal, in terms of content non-metallic spots, and offer to explain, in full, the features of the process that were hard to interpret before. (author)

  11. Détection binaire distribuée sous contraintes de communication

    OpenAIRE

    Katz , Gil

    2017-01-01

    In recents years, interest has been growing in research of different autonomous systems. From the self-dring car to the Internet of Things (IoT), it is clear that the ability of automated systems to make autonomous decisions in a timely manner is crucial in the 21st century. These systems will often operate under stricts constains over their resources. In this thesis, an information-theoric approach is taken to this problem, in hope that a fundamental understanding of the limitations and pers...

  12. Etude hydromecanique d'une fracture en cisaillement sous contrainte normale constante

    Science.gov (United States)

    Lamontagne, Eric

    This research study deals with the effects of shear direction and injection flow rate on the flow directional anisotropy for a given normal stress. It presents experimental works on hydromechanical shear behaviour of a fracture under constant normal stress conditions that permits the characterisation of the intrinsic hydraulic transmissivity in relation with the directional anisotropy of the roughness morphology on the fracture surfaces. Tests were performed on mortar replicas of a natural fracture so that the fracture roughness and void space geometry were kept the same for each test. The experimental work program was performed through direct shear tests on the fracture replicas in four shear directions under four constant normal stress levels. The application of the normal stress was followed by several injections of fluid under constant flow rate. Then, for each defined shear displacement, several injections of fluid were done at different flow rate but under constant flow rate. The test results show that: (1) for the whole shear tests, the global intrinsic transmissivity is included within an enveloping zone of about one order of size. The transmissivity curves within the enveloping zone has a particularity to increase about two orders of size in the first millimetre of shear displacement and subsequently stabilised rapidly; (2) the highest dilatancy do not correspond necessarily with the highest intrinsic transmissivity so that, the behaviour of the global intrinsic transmissivity is not directly proportional to the fracture dilatancy during shear; (3) after the peak shear stress, the divergence is more marked between the global intrinsic transmissivity curves at various flow rate; (4) after peak shear strength and the beginning of asperity degradation, the gradual passage to residual friction shear behaviour causes a directional flow anisotropy and a reorientation of the flow chenalisation direction sub perpendicularly to the shear direction; (5) the anisotropy is not to develop equally between the two sense in the perpendicular direction to shear direction. In order to characterise the dynamics of the flow pattern in the fracture, a statistical analysis of the surfaces morphology of the fracture and the casting of void space geometry were performed before and after shear. A statistical analysis of asperity heights, on the global scale of the fracture surfaces, permits to characterise the fracture morphology and put in evidence a large morphological structure on which are superposed smaller asperities of variable dimensions. This large dimension structure generate a higher level landing occupying more than half of the fracture area. The study of the surfaces morphology of the fracture, performed with the geostatistical mean asperity heights variogram by direction before shearing, show the presence of two entangled morphologic structure families (28 and 15 mm). This same study done after shearing shows that the asperity degradation seems associated with the reduction of the global intrinsic transmissivity of the fracture. Finally, the void spaces morphology evaluated by casting techniques, during the shear tests, has permitted to verify the contacts evolution with the increasing shear displacement and visualised flow chenalisation during fracture shearing.

  13. Contraintes de taille dans les mots composés : quand la phonologie entre en concurrence avec les contraintes morphologiques

    Directory of Open Access Journals (Sweden)

    Villoing Florence

    2012-07-01

    Full Text Available Cette communication porte sur les contraintes phonologiques qui pèsent sur la formation des mots construits dans le cadre théorique de la morphologie lexématique (Anderson 1992, Aronoff 1994, Fradin 2003. En étudiant les données du français, les travaux de Lignon (à paraître, Plénat (2009 & Roché (2003 ont montré que des contraintes de taille étaient à l’œuvre dans plusieurs constructions morphologiques. L’objectif de cet article est d’étudier cette hypothèse sur les mots composés Verbe-Nom du français (Villoing 2009. L’analyse quantitative des données du corpus montre clairement que les verbes des mots composés VN du français sont soumis à des contraintes de taille et doivent répondre au format d’un monosyllabe. La contrainte pèse moins lourdement sur les noms qui parviennent à s’imposer plus facilement que les verbes avec une taille supérieure. Cependant, la majorité des mots composés VN tend à ne pas dépasser trois syllabes (leur format optimal étant de deux ou trois syllabes, révélant ainsi l'influence des contraintes de taille sur le mot composé lui-même. La mise au jour de ces contraintes permet d'expliquer l’absence de certains verbes dans le corpus de composés VN, répondant pourtant bien aux propriétés sémantiques attendues : les verbes construits par affixation (absence de suffixés en -iser, -ifier; très rares cas de préfixés, les verbes du 2ème groupe, les verbes de taille supérieure à trois syllabes. En outre, cet article met au jour un cas de concurrence entre contrainte morphologique et contrainte phonologique au sein d'une construction morphologique, et montre comment la première l'emporte sur la dernière, bien que la contrainte phonologique contraigne fortement le choix du verbe et du nom de base. Il donne également à voir comment la contrainte phonologique parvient néanmoins à influencer le choix de bases sémantiquement peu conformes aux attentes de la règle.

  14. Le cerveau sous effet placebo

    OpenAIRE

    Touzet , Claude

    2017-01-01

    International audience; Comment le fait de croire qu’on nous injecte de la morphine (alors qu’il s’agit de sérum physiologique) peut-il faire disparaître la douleur ? Investigation sur le cerveau sous placebo.

  15. The energy in all states: data, constraints, stakes; L'energie sous toutes ses formes: donnees, contraintes, enjeux

    Energy Technology Data Exchange (ETDEWEB)

    Balian, R [Academie des Sciences, 92 - Gif sur Yvette (France); Combarnous, M [Bordeaux-1 Univ., LEPT-ENSAM, 33 - Talence (France); Lucas, J; Fauvarque, J F [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France); Madet, D [Electricite de France (EDF), 75 - Paris (France); Bal, J L [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France); Jourde, P [CEA Cadarache, GENEC, 13 - Saint-Paul-lez-Durance (France); Tissot, B [Commission Nationale d' Evaluation, 75 - Paris (France); Leconte, Ph [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares DDIN, 91 - Gif Sur Yvette (France); Doubre, H [Paris-11 Univ., IN2P3/CNRS, 91 - Orsay (France); Alleau, Th [Association Francaise de l' Hydrogene, AFH2, 75 - Paris (France); Durup, G [Mining Research Institute (United States); Le Treut, H [Ecole Nationale Superieure, 75 - Paris (France); Tubiana, M [Institut Gustave Roussy, 94 - Villejuif (France); [Centre Antoine Beclere, Paris (France); Masse, R [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France); Lebot, B [Agence Internationale de l' Energie, 75 - Paris (France); Babusiaux, D [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Saab, A E [Electricite de France (EDF), 75 - Paris (France)

    2002-07-01

    This documents brings together papers presented at the physics summer school of august 2001 on the energy. The following topics are discussed: the constraints bound to the physics and the scales, the renewable energies, the future of the nuclear energy and the fossil energies, the energy storage problems, the environmental and sanitary aspects, the energy mastership and economy. (A.L.B.)

  16. The energy in all states: data, constraints, stakes; L'energie sous toutes ses formes: donnees, contraintes, enjeux

    Energy Technology Data Exchange (ETDEWEB)

    Balian, R. [Academie des Sciences, 92 - Gif sur Yvette (France); Combarnous, M. [Bordeaux-1 Univ., LEPT-ENSAM, 33 - Talence (France); Lucas, J.; Fauvarque, J.F. [Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France); Madet, D. [Electricite de France (EDF), 75 - Paris (France); Bal, J.L. [Agence de l' Environnement et de la Maitrise de l' Energie, ADEME, 75 - Paris (France); Jourde, P. [CEA Cadarache, GENEC, 13 - Saint-Paul-lez-Durance (France); Tissot, B. [Commission Nationale d' Evaluation, 75 - Paris (France); Leconte, Ph. [CEA Saclay, Dir. du Developpement et de l' Innovation Nucleares DDIN, 91 - Gif Sur Yvette (France); Doubre, H. [Paris-11 Univ., IN2P3/CNRS, 91 - Orsay (France); Alleau, Th. [Association Francaise de l' Hydrogene, AFH2, 75 - Paris (France); Durup, G. [Mining Research Institute (United States); Le Treut, H. [Ecole Nationale Superieure, 75 - Paris (France); Tubiana, M. [Institut Gustave Roussy, 94 - Villejuif (France)]|[Centre Antoine Beclere, Paris (France); Masse, R. [Office de Protection contre les Rayonnements Ionisants, 78 - le Vesinet (France); Lebot, B. [Agence Internationale de l' Energie, 75 - Paris (France); Babusiaux, D. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Saab, A.E. [Electricite de France (EDF), 75 - Paris (France)

    2002-07-01

    This documents brings together papers presented at the physics summer school of august 2001 on the energy. The following topics are discussed: the constraints bound to the physics and the scales, the renewable energies, the future of the nuclear energy and the fossil energies, the energy storage problems, the environmental and sanitary aspects, the energy mastership and economy. (A.L.B.)

  17. Hydrogen cracking and stress corrosion of pipeline steels. Contribution of the cracking mechanisms study to the understanding of the in-service damage and to the definition of a ranking test; Fissuration assistee par l'hydrogene et corrosion sous contrainte des aciers de pipelines. Apports de l'etude des mecanismes de fissuration a la comprehension de l'endommagement de service et a la definition d'un test de classification

    Energy Technology Data Exchange (ETDEWEB)

    Le Friant, D.

    2000-12-19

    This work is based on the study of the cracking of a French oil transmission pipeline protected by a cathodic protection system. The objective is to identify field parameters, which contribute to the cracks propagation, and to assess changes in the operating conditions, which could lead to a mitigation of the phenomenon. We have focused on the study of the micro-mechanisms by means of slow strain rate tests. Then, cyclic loading tests were carried out to investigate cracks propagation mechanisms. Smooth and pre-notched specimens were tested at free and cathodic potential. Hydrogen is responsible for crack advance through changes in the local steels properties. Such effects take place when two phenomenons occur: favourable conditions for hydrogen entry and, a localisation of hydrogen and its effects. In particular, we have shown the essential role of a dynamic loading in promoting hydrogen entry into the steel (especially at the very crack tip). At cathodic potential, hydrogen-related effects are exacerbated by the presence of MnS inclusions which leads to the initiation of internal cracks (HIC) and to a SOHIC-like crack morphology. At free potential, the lesser amount of available hydrogen give localisation-related effects a greater importance. Cracking is then related to a hydrogen-induced SCC mechanism. Three parameters are involved in the field cracking: operating pressure variations, period of over-protection and a sensitive steels microstructure (MnS). Cathodic protection appears to be the most efficient field parameter to mitigate the phenomenon: it requires a better control of the polarisation level. Finally, a ranking test is outlined from the study of the cracking mechanisms. (author)

  18. Influence de la contrainte moyenne sur la tenue en fatigue de l ...

    African Journals Online (AJOL)

    Dans ce cadre, le présent document montre l\\'influence de la contrainte moyenne sur l\\'amplitude des contraintes de deux alliages d\\'aluminium, le 1200 et le 5005 ... This model is near to experimental reality for the Al alloy1200 but badly estimate the effect of means stress on the stress amplitudes for the Al alloy 5005 H18.

  19. SOUS LES PAVÉS: LA PLAGE!

    DEFF Research Database (Denmark)

    Clemmensen, Thomas Juel

    2017-01-01

    kunstnerbevægelse situationisterne brugte parolen sous les pavés: la plage! blev stranden associeret med det frie naturlige rum i kontrast til den brolagte gade, der repræsenterede samfundets undertrykkende orden. Men udtrykket kan samtidig minde os om geologiens allestedsnærværende karakter. Geologien findes lige...

  20. Study of hydrogen migration produced during the corrosion of PWR reactors fuel cans in zircaloy 4 and zirconia; Etude du transport de l`hydrogene produit lors de la corrosion des gaines d`elements combustibles des reacteurs a eau sous pression dans la zircone et le zircaloy-4

    Energy Technology Data Exchange (ETDEWEB)

    Aufore, L

    1997-12-12

    The corrosion of Zircaloy-4-claddings by water from the primary circuit of nuclear power plant goes hand in hand with the release of hydrogen which penetrates the oxide and then the metal. This work focuses on the mechanisms of hydrogen transport in oxide and in metal. Hydrogen transport in oxide is studied on the basis of corrosion tests performed in the autoclave at 360 deg C. These tests are performed on Zircaloy-4 claddings under different chemical conditions (pure water, and pure water with lithium hydroxide). The distribution of hydrogen in oxide film is measured by SIMS. Hydrogen profiles in the oxide are dependent on the oxide microstructure and vary with oxidation time. These observations are confirmed by experiments in which some samples, previously oxidized in the autoclave, are immersed in heavy water. In the oxide layer, two zones are observed: one external porous zone and one internal dense zone. Deuterium diffusion coefficients in dense oxide are determined using SIMS profiles and Fischer diffusion model. Hydrogen transport in metal is also studied by means of gas-phase permeation experiments. These are set up at different temperature (400-500 deg. C) and under different hydrogen pressures and make it possible to determine the hydrogen diffusion coefficients in a Zircaloy-4 cladding under experimental conditions. All these results lead us to discuss of hydrogen transport evolution in cladding during oxidation. A model taking into account hydrogen transport in oxide and in metal, and the hydrides precipitations is proposed. (author) 110 refs.

  1. Clichy-sous-Bois (France) operation

    Energy Technology Data Exchange (ETDEWEB)

    Dechamp, A

    1984-09-01

    The geothermal plant of Clichy-sous-Bois has been operating for 2 years and covers the needs of 3,400 equivalent-dwellings, including a sport-hall, 2 schools, the town-hall and 7 low-cost groups of flats. Geothermal energy covers 65% of the energy yearly global consumption for heating and sanitary hot water, i.e. 35,151 MWh. Thus, 3,195 TOE are saved each year. In December, 1979, the town of Clichy-sous-bois delegated their sponsorship to the Societe d'equipement et d'amenagement du territoire du departement de la Seine-Saint-Denis - SODETAT 93 for the realization of the geothermal operation. The production and injection wells were drilled between July and September, 1981. The Dogger aquifer was encountered at 1,800 m deep, with a temperature of 70,8/sup 0/C and an exploitation yield of 200m/sup 3//h. Surface works started in March 1982 and were completed in November of the same year. Apart from the geothermal power plant, the network comprises 11 exchange substations and a distribution network of 2,700 m long with 7,000 m of underground pipes. This plant is exploited by the Compagnie francaise d'exploitation thermique (COFRETH) within the framework of a farmout contract for 20 years, including: production, transportation and public distribution of geothermal heat all over the city of Clichy-sous-Bois.

  2. Aphasie : Contraintes vs Gouvernement, le cas des clusters

    Directory of Open Access Journals (Sweden)

    Prince Typhanie

    2012-07-01

    Full Text Available L'objet de ce travail est de comprendre les processus phonologiques qui structurent le langage : pathologique ou non. Notre approche apparie phonologie et aphasiologie. Nous proposons ici une analyse de ces processus phonologiques à travers l'étude des groupes consonantiques dans les structures syllabiques dont ils dépendent. Le cas des clusters apparaît essentiel dans cette problématique. Cet objet n'est que trop peu exploité dans les travaux aphasiologiques alors qu'il s'avère central dans les approches phonologiques par les problèmes représentationnels qu'il pose : relations ou absence de relations entre les consonnes, hétérosyllabicité ou ambisyllabicité. Notre étude prend en compte : - une dimension segmentale : à travers la notion de complexité, - une dimension syllabique : par les relations de gouvernement imposées sur les représentations phonologiques. Nous postulons que ce n'est qu'en considérant l'interrelation de ces dimensions que l'on peut produire une explication des désordres phonologiques observés en pathologie et montrer que des régularités émergent. Dans cet article, nous exposons les traitements proposées à l'aphasie à travers deux cadres phonologiques : la Théorie de l'Optimalité [OT] et la Théorie des Contraintes et des Stratégies de Réparation [TCSR]. Il s'agit d'observer les apports et limites rencontrés par ces modèles. Ensuite, à partir de la Phonologie du Gouvernement, cadre dans lequel nous nous situons, depuis [KLV : 1985] jusqu'à [Scheer : 2010], nous analysons les données et exposons une explication des phénomènes tant au niveau segmental que syllabique. L'étude est basée sur un échantillon de 15 aphasiques (Broca, Wernicke, Conduction de l'unité Neuro- Vasculaire du CHU de Nantes : tous souffrent d'une aphasie consécutive à une lésion cérébrale. Les données ont été récoltées au maximum 72h après le traumatisme à partir d'un protocole expérimental destiné

  3. Radiculoplexopathie, anticorps anti Yo et cancer ovarien sous ...

    African Journals Online (AJOL)

    Les radiculo-plexopathies au cours des cancers sont le plus souvent d'origine métastatique. Leur origine dysimmune est rare. Nous rapportons un cas de radiculoplexopathie d'évolution favorable sous traitement immunomodulateur, survenue chez une patiente porteuse d'un carcinome ovarien bilatéral sous ...

  4. Palatability of sous vide processed chicken breast.

    Science.gov (United States)

    Turner, B E; Larick, D K

    1996-08-01

    The influences of brine composition, internal temperature, heating rate, and storage periods up to 28 d on flavor, texture, and color of sous vide processed chicken breast were evaluated. Pectoralis major muscles containing water and sodium chloride, with or without sodium lactate, were browned and vacuum packaged. Sous vide processing was by fast or slow heating to an internal temperature of 77 or 94 C. Product was evaluated after 0, 14, and 28 d storage at 4 C. Quality was evaluated by gas chromatographic analyses of flavor volatiles, shear, color, and sensory panels. Incorporation of sodium lactate into brine did not influence oxidative stability (as measured by headspace gas chromatography) or sensory warmed-over flavor. Presence of sodium lactate did result in enhanced fresh roasted or meaty and saltiness sensory scores as well as a more yellow color. The more rapid heating rate decreased sulfur-containing compounds and did not influence other volatile concentrations. Products processed to 94 C were less juicy, less tender, and contained higher quantities of alcohols and hydrocarbons than those processed to 77 C. Storage resulted in a decline in fresh roasted or meaty flavor note and an increase in warmed-over flavor note and quantities of alcohols, aldehydes and ketones, hydrocarbons, and total headspace volatiles.

  5. Tambaqui (Colossoma macropomum sous vide: characterization and quality parameters

    Directory of Open Access Journals (Sweden)

    Fabiane de Cássia Pontes Ramos

    2016-02-01

    Full Text Available The objective of this study was to evaluate the microbiological, physical and physico-chemical quality parameters of sous vide preparation of pen-reared tambaqui (Colossoma macropomum. To prepare the tambaqui sous vide, 200 g of fillet, 50 g of basil sauce (1:4 fish fillet:sauce ratio and 10 mL of 5% sodium lactate were used. The product was then vacuum-packaged, pasteurized at 65 ºC for 12.5 min and refrigerated. The presence of Salmonella spp., sulfite-reducing Clostridium and Listeria monocytogenes was not detected in the samples analyzed. The coliform count at 45 ºC and coagulase-positive staphylococci were below the limit (103 permitted by the law in vigor. Water retention capacity and chloride content analyses revealed that the tambaqui fillet differed significantly (P<0.05 from the sous vide because of the addition of basil sauce. The total volatile basic nitrogen (TVB-N and thiobarbituric acid reactive substances (TBARS content of the fillet and sous vide were below the limits established by the law, indicating good quality. The lightness (L* and yellow color (b* of the fillet and the sous vide did not differ significantly (P>0.05, but the red color (a* decreased in the sous vide, which is related to the addition of basil sauce. The chroma (C* and hue angle (ho differed significantly (P<0.05, and the fillet samples were lighter in color, whereas the sous vide was characterized by yellow color. The n-6/n-3 ratios found for the fillet and the sous vide are within the recommended values, which is important for human metabolism. The fillet and sous vide also had high calcium, zinc, magnesium and potassium concentrations. It is concluded that tambaqui sous vide is a good source of nutrients, rich in fatty acids and minerals essential for human health.

  6. Corrosion and corrosion control

    International Nuclear Information System (INIS)

    Khanna, A.S.; Totlani, M.K.

    1995-01-01

    Corrosion has always been associated with structures, plants, installations and equipment exposed to aggressive environments. It effects economy, safety and product reliability. Monitoring of component corrosion has thus become an essential requirement for the plant health and safety. Protection methods such as appropriate coatings, cathodic protection and use of inhibitors have become essential design parameters. High temperature corrosion, especially hot corrosion, is still a difficult concept to accommodate in corrosion allowance; there is a lack of harmonized system of performance testing of materials at high temperatures. In order to discuss and deliberate on these aspects, National Association for Corrosion Engineers International organised a National Conference on Corrosion and its Control in Bombay during November 28-30, 1995. This volume contains papers presented at the symposium. Paper relevant to INIS is indexed separately. refs., figs., tabs

  7. Dictionary corrosion and corrosion control

    International Nuclear Information System (INIS)

    1985-01-01

    This dictionary has 13000 entries in both languages. Keywords and extensive accompanying information simplify the choice of word for the user. The following topics are covered: Theoretical principles of corrosion; Corrosion of the metals and alloys most frequently used in engineering. Types of corrosion - (chemical-, electro-chemical, biological corrosion); forms of corrosion (superficial, pitting, selective, intercrystalline and stress corrosion; vibrational corrosion cracking); erosion and cavitation. Methods of corrosion control (material selection, temporary corrosion protection media, paint and plastics coatings, electro-chemical coatings, corrosion prevention by treatment of the corrosive media); Corrosion testing methods. (orig./HP) [de

  8. Lipoblastome de la fosse sous temporale

    Science.gov (United States)

    Najib, Jaafar; Aniba, Khalid; Laghmari, Mehdi; Lmejjati, Mohammed; Ghannane, Houssine; Benali, Said Ait; Ennadam, Hind; Mrabti, Hind; Idrissi, Nadia Cherif

    2014-01-01

    Le lipoblastome est une tumeur bénigne rare, formée d'adypocytes immatures associés à la présence d'une matrice myxoide, de septas fibreux, et d'une architecture lobulaire. Il survient généralement chez le nourrisson et l'enfant. Cette tumeur touche dans la majorité des cas les tissus sous-cutanés des extrémités et du tronc. Elle est extrèmement rare au niveau de la tète et du cou. Un total de moins de 100 cas a été rapporté précédemment dans la littérature. PMID:25918563

  9. The Sous Vide Revolution: Coming Full Circle and Beyond

    OpenAIRE

    Hoeche, Ulrich

    2016-01-01

    For the purpose of this research, academic material and online sources were utilised to clarify the meaning of the key term sous vide. The Sous Vide Advisory Committee (1991) says ‘Sous Vide (also known as Cuisine en Papillote) is an interrupted catering system in which raw or par-cooked food is sealed into a vacuumised laminated plastic pouch or container, heat treated by controlled cooking, rapidly cooled and then reheated for service after a period of chilled storage’. According to Herb...

  10. Multi variable control of a switched ignition device: efficiency improvement under various constraints; Commande multivariable d`un moteur a allumage commande: Amelioration du rendement sous differentes contraintes

    Energy Technology Data Exchange (ETDEWEB)

    Chaumerliac, V

    1995-03-09

    Spark-ignition engine control needs substantial improvement for various reasons: a non-linear and multivariable process, the strictness of anti-pollution constraints, the necessity of fuel economy, the variable running conditions, the aging, the reliability and the cost. The improvement of engine efficiency will be involved in this context and with the pollution constraints. This work develops a system approach and its philosophy is based on a suitable description of the main dynamics. A compartmentalized model of a spark-ignition engine and the dynamic of the vehicle is presented. The aim of this modeling is to have a good representativeness in transients and to describe the behavior of the outputs useful for control. The multivariable control is split in two independent systems. The first one controls the spark advance control to obtain the maximum torque. The second one controls the throttle and the electronic fuel injection device to have lower pollutant emissions. The spark advance closed loop control uses information measured with either a cylinder pressure sensor or a torque sensor. These studies have achieved to an adaptive tuning on engine bench. A new actuator, the electronic throttle control, can provide a higher degree of precision for the fuel/air ratio regulation system, particularly during fast accelerations and decelerations. An intake manifold pressure control is developed to coordinate the air and fuel flows. A delay strategy and a simple compensation of fuel supply dynamics allow to obtain good results on engine bench. Uncoupling the acceleration pedal and the throttle command is a promising way to improve engine efficiency and reduce exhaust emission during transient phases. (author) 59 refs.

  11. Commande de systèmes linéaires sous contraintes fréquentielles et temporelles – Application au lanceur flexible

    OpenAIRE

    Chambon , Emmanuel

    2016-01-01

    In modern control design problems, both frequency- and time-domain requirements are usually considered such that the resulting control law satisfies the specifications. Novel non-smooth optimisation techniques can be used to achieve multiple frequency-domain specifications over a family of linear models. Examples of applications include robust control design where multiple critical models for different values of the uncertain parameters are considered. This is illustrated in this thesis manus...

  12. Contraintes d'adoption des technologies de gestion de la fertilite des ...

    African Journals Online (AJOL)

    La baisse de fertilité des sols, l'une des principales contraintes du secteur agricole au Togo, sévit encore plus dans la riziculture irriguée où les terres sont exploitées chaque année sans jachère. Face à cette situation, diverses solutions comme les technologies de gestion de la fertilité des sols ont été proposées.

  13. contraintes d'adoption des technologies de gestion de la fertilite des ...

    African Journals Online (AJOL)

    La baisse de fertilité des sols, l'une des principales contraintes du secteur agricole au Togo, sévit encore plus dans la riziculture irriguée où les terres sont exploitées chaque année sans jachère. Face à cette situation, diverses solutions comme les technologies de gestion de la fertilité des sols ont été proposées.

  14. La base sous-marine de Bordeaux, sous le béton la culture

    Directory of Open Access Journals (Sweden)

    Mathieu Marsan

    2012-06-01

    Full Text Available Active à peine plus d’un an pendant l’Occupation, la base sous-marine de Bordeaux cristallise encore les souvenirs douloureux des heures sombres du Port de la Lune. Le bunker attire pourtant depuis les années 1960 des artistes, cinéastes, plasticiens et musiciens fascinés par l’esprit du lieu. Institutionnalisée au début des années 1990, la base sous-marine devient un espace dédié au nautisme avant d’être consacrée à l’art contemporain au début du XXIe siècle. Aujourd’hui au cœur du projet d’aménagement des bassins à flot du quartier de Bacalan, la base sous-marine questionne et intrigue ses visiteurs sur son passé, mais aussi – et surtout – sur son avenir.Build during the German occupation, the submarine base of Bordeaux active during hardly more than a year still crystallizes the painful memories of the dark hours of the « Port de la Lune ». Nevertheless, the bunker attracts artists, film-makers, visual artists and musicians fascinated by the spirit of the place since the 1960’s. Institutionalized at the beginning of 1990’s, the submarine base became a space dedicated to the yachting before contemporary art at the beginning of the XXIth century. Nowadays at the heart of the project of redevelopment of the wet docks in the urban area of Bacalan, the submarine base questions and intrigues its visitors on its past, but also – and especially – on its future.

  15. Fertilité des sols agricoles sous vigne et sous blé de la région de ...

    African Journals Online (AJOL)

    L'objectif de ce travail est l'évaluation agronomique de la qualité du sol sous vigne et sous blé dans la région Mohammedia-Benslimane au Maroc, à travers les indicateurs chimiques de la qualité du sol (pH, CE, CaCO3, Carbone organique total, Azote, Phosphore et Potassium). Les résultats de cette étude montrent que ...

  16. Corrosion cracking

    International Nuclear Information System (INIS)

    Goel, V.S.

    1985-01-01

    This book presents the papers given at a conference on alloy corrosion cracking. Topics considered at the conference included the effect of niobium addition on intergranular stress corrosion cracking, corrosion-fatigue cracking in fossil-fueled-boilers, fracture toughness, fracture modes, hydrogen-induced thresholds, electrochemical and hydrogen permeation studies, the effect of seawater on fatigue crack propagation of wells for offshore structures, the corrosion fatigue of carbon steels in seawater, and stress corrosion cracking and the mechanical strength of alloy 600

  17. Corrosion engineering

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, M.G.

    1986-01-01

    This book emphasizes the engineering approach to handling corrosion. It presents corrosion data by corrosives or environments rather than by materials. It discusses the corrosion engineering of noble metals, ''exotic'' metals, non-metallics, coatings, mechanical properties, and corrosion testing, as well as modern concepts. New sections have been added on fracture mechanics, laser alloying, nuclear waste isolation, solar energy, geothermal energy, and the Statue of Liberty. Special isocorrosion charts, developed by the author, are introduced as a quick way to look at candidates for a particular corrosive.

  18. Étude de l'état de contrainte du sol et des organes de travail des ...

    African Journals Online (AJOL)

    SARAH

    30 déc. 2013 ... Biodiversité des emballages-feuilles végétales utilisées dans ... contrainte du sol lors du processus d'interaction avec différents organes de travail des machines .... paramètres suivants : erreur combinée: 0,1%, classe de.

  19. Transhumance en République du Bénin : états des lieux et contraintes

    African Journals Online (AJOL)

    Les résultats ont également permis de voir qu'elle est confrontée à des problèmes d'alimentation, de variabilités climatiques, des textes règlementaires, de conflits et de disponibilités des infrastructures pastorales. Il ressort également que la transhumance demeure sous la forte influence des systèmes de culture surtout ...

  20. Deep geothermal energy: the Soultz-sous-Forets experience

    International Nuclear Information System (INIS)

    Genter, A.; Guenot, N.; Graff, J.J.

    2010-01-01

    This paper presents the mining exploitation project of the geothermal heat at Soultz-sous-Forets, located 50 km NE of Strasbourg (Bas Rhin, France). A geothermal power plant, inaugurated mid-2008, will commercialize its own power generation soon. This power plant is owned by a consortium of French-German industrialists through the European economical interest group for the mining exploitation of heat. The paper presents the geological characteristics of the hot dry rock geothermal reservoir, the deep geothermal wells, the hydraulic stimulation of the reservoir rock, the surface equipments of the power plants and the production pumps, the activities of the site in 2008 and 2009 and the perspectives of development of this energy source in France in the light of the Soultz-sous-Forets site experience. (J.S.)

  1. L’algoculture et ses contraintes géographiques en Chine

    Directory of Open Access Journals (Sweden)

    Sophie Litzler

    2012-02-01

    Full Text Available La production aquacole mondiale a un taux de croissance annuel moyen de 6,2 % (2003-2008. La production des végétaux marins suit cette tendance avec 15,8 millions de tonnes d’algues cultivées. La Chine est le premier cultivateur mondial avec 10 millions de tonnes mais en 2008 elle a signalé une baisse de 13 % de sa production aquacole. Cet article souhaite montrer en quoi de nouvelles contraintes géographiques peuvent limiter le développement de l’algoculture malgré le grand potentiel de la filière. Nous présenterons un état des lieux mondial de cette activité puis une typologie de ces contraintes. Nous illustrerons cet axe de recherche par des études de cas sur la Chine.The global aquaculture production has an average annual growth rate of 6.2 per cent (2003-2008. The production of marine plants follows this trend with 15.8 million tons of seaweed farmed. China is the first world farming country with 10 million, tons but in 2008 it reported a 13 per cent drop in its production. Based on this observation, this article intends to show the geographical restrictions that may limit the development of seaweed farming. We shall present an overview of this activity on a global scale then we shall expose a typology of these restrictions. Finally we shall illustrate this research with several case studies.

  2. La violence dans les services sociaux: situation dans les services d'aide contrainte du canton du Jura

    OpenAIRE

    Durand, Loriane; Favre, Eliane

    2017-01-01

    Mon Travail de Bachelor a pour but premier de prendre connaissance de la situation de la violence dans les services d’aide contrainte du canton du Jura. La violence est-elle une réalité ? De quels types de violence s’agit-il ? Pourquoi cette violence, quelles en sont les raisons ? Cette violence augmente-t-elle le stress dans la profession d’assistant social ?

  3. Oxidation of steel heated in CO{sub 2} medium under pressure; Oxydation d'un acier ordinaire chauffe dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R.; Leclercq, D.; Bunard, C. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Behaviour of low-alloyed steels heated in CO{sub 2} medium under pressure is reported. Tests are carried out in the range of erature reached in the CO{sub 2} cooled reactors (vessel, thermal shield, pipes). The observed weight increases are small, even after more than a thousand hours of heating at 350 deg. C, but oxidation curve looks like progressing linearly. Furthermore, the oxide formed under a pressure of 15 kg/cm{sup 2} is undoubtedly more compact and adherent than the one formed under a pressure of 1 kg/cm{sup 2}. Finally, for practical use, CO{sub 2} steel pipes surface has to be sand blast and pickled. A following phosphatizing protects it from atmospheric corrosion during assembling, but these treatments have no influence on the behaviour of these steels heated in CO{sub 2}. (author)Fren. [French] On etudie le comportement d'aciers au carbone faiblement allies, chauffes dans le gaz carbonique sous pression, aux temperatures atteintes dans les reacteurs refroidis par ce gaz (caisson, bouclier thermique, canalisations). Les augmentations de poids observees sont faibles, meme apres plus de 1000 heures de chauffage a 350 deg. C, mais l'oxydation semble se poursuivre lineairement. De plus, l'oxyde forme dans le gaz carbonique sous pression de 15 kg/cm{sup 2} est nettement plus compact et adherent que celui forme sous pression atmospherique de gaz carbonique. Enfin, dans la pratique, les surfaces d'acier du circuit de gaz carbonique sont necessairement sablees ou decapees; une phosphatation ulterieure le protege de la corrosion atmospherique pendant le montage. Ces traitements sont sans influence sur le comportement de ces aciers dans le gaz carbonique a chaud. (auteur)

  4. Oxidation of steel heated in CO{sub 2} medium under pressure; Oxydation d'un acier ordinaire chauffe dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Darras, R; Leclercq, D; Bunard, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Behaviour of low-alloyed steels heated in CO{sub 2} medium under pressure is reported. Tests are carried out in the range of erature reached in the CO{sub 2} cooled reactors (vessel, thermal shield, pipes). The observed weight increases are small, even after more than a thousand hours of heating at 350 deg. C, but oxidation curve looks like progressing linearly. Furthermore, the oxide formed under a pressure of 15 kg/cm{sup 2} is undoubtedly more compact and adherent than the one formed under a pressure of 1 kg/cm{sup 2}. Finally, for practical use, CO{sub 2} steel pipes surface has to be sand blast and pickled. A following phosphatizing protects it from atmospheric corrosion during assembling, but these treatments have no influence on the behaviour of these steels heated in CO{sub 2}. (author)Fren. [French] On etudie le comportement d'aciers au carbone faiblement allies, chauffes dans le gaz carbonique sous pression, aux temperatures atteintes dans les reacteurs refroidis par ce gaz (caisson, bouclier thermique, canalisations). Les augmentations de poids observees sont faibles, meme apres plus de 1000 heures de chauffage a 350 deg. C, mais l'oxydation semble se poursuivre lineairement. De plus, l'oxyde forme dans le gaz carbonique sous pression de 15 kg/cm{sup 2} est nettement plus compact et adherent que celui forme sous pression atmospherique de gaz carbonique. Enfin, dans la pratique, les surfaces d'acier du circuit de gaz carbonique sont necessairement sablees ou decapees; une phosphatation ulterieure le protege de la corrosion atmospherique pendant le montage. Ces traitements sont sans influence sur le comportement de ces aciers dans le gaz carbonique a chaud. (auteur)

  5. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  6. Plate forme L3 informatique sous application android

    OpenAIRE

    BENDEDDOUCHE, Rida; BENAMARA, Mohammed El Amin

    2014-01-01

    Ce travail est présenté dans le cadre de notre projet de fin d’étude licence en informatique. Nous sommes actuellement dans une étape de transition de l’informatique fixe à l’informatique mobile. De jour en jour l’optimisation des smartphones ne cesse d’augmenter et cela grâce aux applications mobiles. Les smartphones utilisent plusieurs systèmes d’exploitation, une grande partie est sous Android. Les Smartphones et tablettes ont été conçus pour faciliter la vie quotidienne. En partant de ce ...

  7. Composes inter-halogenes sous pression: etude des transformations structurales dans le monobromure d'iode sous forme dense

    Science.gov (United States)

    Bouchard, Alexandre

    La famille des composes halogenes et inter-halogenes representent des solides moleculaires adoptant des phases denses communes avec des solides moleculaires diatomiques comme l'azote et l'hydrogene. Parmi les transformations structurales et electroniques induites sous haute pression et observees dans ces solides, on note, entre autres, la dissociation moleculaire et la metallisation. De plus, l'etude des phases denses de l'iode a permis recemment l'observation d'une structure cristalline possedant une modulation dite incommensurable, c'est-a-dire une modulation possedant une periodicite differente de celle de la structure cristalline, jetant ainsi une lumiere nouvelle sur le processus de dissociation moleculaire dans les solides halogenes. Dans ce memoire, on propose d'etudier les changements structuraux dans monobromure d'iode (IBr), un compose inter-halogene possedant des proprietes structurales semblables a celles de deux composes halogenes, soit l'iode (I 2) et le brome (Br2) sous leur forme solide. Des experiences de diffraction des rayons X de poudres en utilisant un rayonnement synchrotron ont ete realisees a temperature ambiante sur l'IBr en variant la pression jusqu'aux environs de 60 GPa. La nature chimique particuliere du compose IBr a necessite la mise au point de techniques de chargement d'echantillon destinees a preserver l'integrite chimique de la substance utilisee. On rapporte egalement l'observation d'une phase de l'IBr presentant une modulation incommensurable. Les phases observees dans l'IBr permettent d'etablir des paralleles avec les phases denses rapportees dans I2 et Br2 par le biais d'un modele phenomenologique decrivant la sequence structurale des solides halogenes sous forme condensee.

  8. Le harcèlement organisationnel des relations sous emprise

    CERN Document Server

    Guhel, Cécile

    2014-01-01

    Le lien entre harcèlement et emprise professionnelle est bien réel. Il est aussi puissant que destructeur. L'aide extérieure est importante mais la prise de conscience du sujet et sa mise à distance sont primordiales pour le retour à Soi. Un facteur de risque organisationnel est un facteur qui relève de l'organisation et qui comporte le risque ou la probabilité qu'un tel comportement abusif voie le jour et qu'il ait des effets négatifs. Un tel facteur peut également contribuer à la persistance ou à l'aggravation du comportement. En abordant la relation d'emprise sous l'éclairage de différentes théories psychologiques, cela vous permettra d'observer les mécanismes intrapsychiques conscients et inconscients qui sous-tendent les comportements de l'instigateur de la relation d'emprise d'une part, et de sa victime d'autre part. Enfin, à travers trois témoignages, de salariées en poste, vous découvrirez combien la parole sur le travail est importante dans la prise de conscience du processus de de...

  9. Changes in Meat Quality Characteristics of the Sous-vide Cooked Chicken Breast during Refrigerated Storage.

    Science.gov (United States)

    Hong, Go-Eun; Kim, Ji-Han; Ahn, Su-Jin; Lee, Chi-Ho

    2015-01-01

    This study was performed to investigate the changes in meat quality characteristics of the sous vide cooked chicken breast during refrigerated storage at 4℃ for 14 d between before and after sous-vide cooking. Cooking loss and shear force were significantly increased, whereas expressible drip was significantly decreased along with reduction in the water holding capacity in both of two groups. Redness of meat juice was significantly (p<0.05) increased during storage, and considerably increased in the refrigerated samples after sous-vide cooked at the 7 to 10 d. The thiobarbituric acid reactive substances (TBARS) was significantly increased and was higher in the refrigerator stored chicken breast samples after sous-vide cooking. The volatile basic nitrogen (VBN) value was significantly increased in both groups, but the VBN value of the stored raw meat sample before sous-vide cooking was increased at an early storage, while the VBN value of the stored sample after sous-vide cooking was increased gradually in this study. Total viable counts and coliform counts were significantly decreased during storage, and coliforms were not detected after 7 d of storage in both groups. Salmonella spp. was not detected during the whole studied period. The outcome of this research can provide preliminary data that could be used to apply for further study of chicken breast using sous-vide cooking method that could be attractive to consumers.

  10. Pollution urbaine : la France sous le dôme

    OpenAIRE

    Laurent, Eloi

    2017-01-01

    Un an exactement après avoir accueilli la COP21, Paris suffoquait début décembre sous un dôme de pollution, mais aussi Lyon, Villeurbanne, Marseille, Avignon, Rouen ou Grenoble. Airparif, qui a relevé un niveau de particules fines de 146 µg/m3 à Paris en moyenne pour le 1er décembre, précisait dans un communiqué qu’il s’agissait là d’un des pics hivernaux de pollution les plus sévères de ces dix dernières années, les précédents remontant à janvier 2009 et décembre 2007.

  11. Corrosion in airframes

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  12. La physique des tas de sable Description phénoménologique de la propagation des contraintes dans les matériaux granulaires

    Science.gov (United States)

    Claudin, Ph.

    ène : les forces que l'on applique à un empilement sont majoritairement supportées et véhiculées par une fraction seulement des grains, qui forment alors de véritables chaînes de force ou voûtes. Il en découle par exemple que le profil de pression sous un tas de sable dépend de la manière dont celui-ci a été construit. Pour décrire quantitativement ces effets, nous avons proposé une relation phénoménologique de friction entre les voûtes. Les équations différentielles qui en résultent sont de type hyperbolique. Cela signifie en particulier qu'il existe des lignes privilégiées de propagation appelées caractéristiques, que nous avons fait coïncider avec ces voûtes. Ces modèles reproduisent bien les données expérimentales, et permettent entre autres d'expliquer la présence d'une dépression au centre du tas lorsque celui-ci est construit avec un entonnoir. Ils améliorent également les prédictions du modèle de Janssen pour le silo. Nous nous sommes aussi intéressés aux fluctuations de ces contraintes, et nous avons mis en évidence le caractère fragile i.e. réarrangeant d'un empilement granulaire. Ceci a particulièrement été étudié au sein d'un modèle scalaire très simple qui permet de visualiser les variations de la structure interne d'un système granulaire et les changements dans la distribution des forces qui en résulte.

  13. Corrosion inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, A O

    1965-12-29

    An acid corrosion-inhibiting composition consists essentially of a sugar, and an alkali metal salt selected from the group consisting of iodides and bromides. The weight ratio of the sugar to the alkali metal salt is between 2:1 and about 20,000:1. Also, a corrosion- inhibited phosphoric acid composition comprising at least about 20 wt% of phosphoric acid and between about 0.1 wt% and about 10 wt% of molasses, and between about 0.0005 wt% and about 1 wt% of potassium iodide. The weight ratio of molasses to iodide is greater than about 2:1. (11 claims)

  14. Corrosion inhibitors

    International Nuclear Information System (INIS)

    El Ashry, El Sayed H.; El Nemr, Ahmed; Esawy, Sami A.; Ragab, Safaa

    2006-01-01

    The corrosion inhibition efficiencies of some triazole, oxadiazole and thiadiazole derivatives for steel in presence of acidic medium have been studied by using AM1, PM3, MINDO/3 and MNDO semi-empirical SCF molecular orbital methods. Geometric structures, total negative charge on the molecule (TNC), highest occupied molecular energy level (E HOMO ), lowest unoccupied molecular energy level (E LUMO ), core-core repulsion (CCR), dipole moment (μ) and linear solvation energy terms, molecular volume (V i ) and dipolar-polarization (π *), were correlated to corrosion inhibition efficiency. Four equations were proposed to calculate corrosion inhibition efficiency. The agreement with the experimental data was found to be satisfactory; the standard deviations between the calculated and experimental results ranged between ±0.03 and ±4.18. The inhibition efficiency was closely related to orbital energies (E HOMO and E LUMO ) and μ. The correlation between quantum parameters and experimental inhibition efficiency has been validated by single point calculations for the semi-empirical AM1 structures using B3LYP/6-31G** as a higher level of theory. The proposed equations were applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds

  15. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  16. Vacuum welding of metals; Soudage des metaux sous vide

    Energy Technology Data Exchange (ETDEWEB)

    Stohr, J A; Briola, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    This new welding process has been developed by the Commissariat a l'Energie Atomique (CEA) in France. The edges of the work-pieces are melted by the impact of an electron beam produced by an electron gun. Welding is carried out in a vacuum of 10{sup -4} to 10{sup -8} mm of mercury. The welding machine consists, diagrammatically, of: a) a metal enclosure in which a vacuum is produced; b) a cathode for electron emission, a high-voltage generator for accelerating these electrons, a focusing device; c) a mechanical device for moving (rotating) the work-piece. Advantages of the process: 1) possible welding of highly oxidizable metals (e.g. zirconium); 2) fabrication of high-vacuum-sealed metal containers; 3) production of very deeply penetrated welds. Therefore, this new process is particularly advantageous for atomic power applications, the fabrication of electron tubes and, more generally, for all industries in which very special metals are used. (author) [French] Ce procede de soudage a ete recemment mis au point au Commissariat a l'Energie Atomique en France (CEA). Il consiste a utiliser, pour fondre les levres des pieces a souder, l'impact d'un faisceau d'electrons produit par un canon a electrons. Le soudage s'effectue sous un vide de 10{sup -4} a 10{sup -8} mm de mercure. La machine a souder se compose schematiquement: a) d'une enceinte metallique ou l'on fait le vide; b) d'une cathode emettant des electrons, d'un generateur H.T. permettant d'accelerer ces electrons d'un dispositif de focalisation; c) d'un dispositif mecanique permettant le deplacement (rotation) de la piece a souder. Avantages de ce procede: 1) possibilite de souder les metaux tres oxydables (exemple: zirconium); 2) realisation de 'containers' metalliques fermes sous vide pousse; 3) obtention de profondeurs de soudures considerables. Ce nouveau procede est donc particulierement interessant pour l ' energie atomique, la fabrication des tubes electroniques et, en general, toutes les industries

  17. Corrosion/95 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1995-01-01

    The papers in this conference represent the latest technological advances in corrosion control and prevention. The following subject areas are covered: cathodic protection in natural waters; materials for fossil fuel combustion and conversion systems; modern problems in atmospheric corrosion; innovative ideas for controlling the decaying infrastructure; deposits and their effects on corrosion in industry; volatile high temperature and non aqueous corrosion inhibitors; corrosion of light-weight and precoated metals for automotive application; refining industry corrosion; corrosion in pulp and paper industry; arctic/cold weather corrosion; materials selection for waste incinerators and associated equipment; corrosion measurement technology; environmental cracking of materials; advancing technology in the coating industry; corrosion in gas treating; green inhibition; recent advances in corrosion control of rail equipment; velocity effects and erosion corrosion in oil and gas production; marine corrosion; corrosion of materials in nuclear systems; underground corrosion control; corrosion in potable and industrial water systems in buildings and its impact on environmental compliance; deposit related boiler tube failures; boiler systems monitoring and control; recent developments and experiences in reactive metals; microbiologically influenced corrosion; corrosion and corrosion control for steel reinforced concrete; international symposium on the use of 12 and 13 Cr stainless steels in oil and gas production environments; subsea corrosion /erosion monitoring in production facilities; fiberglass reinforced pipe and tubulars in oilfield service; corrosion control technology in power transmission and distribution; mechanisms and methods of scale and deposit control; closing the loop -- results oriented cooling system monitoring and control; and minimization of aqueous discharge

  18. Heat extraction from deep rocks at Soultz-sous-Forets

    International Nuclear Information System (INIS)

    Gerard, A.; Baumgaeriner, J.; Baria, R.

    1996-01-01

    A European coordinated research program for the study of hot-dry-rock systems is in progress at Soultz-sous-Forets (Alsace, France). The aim of this project is the extraction of heat from the granite batholiths distributed along the Rhine graben. The technique used involves important forced water circulations under relatively low-pressures using the natural geologic fractures network. The region concerned extends about 3000 km 2 under both the French and the German territories. The program started in 1987 with preliminary scientific investigations followed by a feasibility study. In December 1995, two deep wells, GPK1 (3600 m) and GPK2 (3900 m) were available and equipped for hydraulic testing. Temperatures encountered can reach 168 C at 3800 m with a geothermal gradient exceeding 3.5 C/100 m below 3600 m. The tests performed have shown that the hydraulic performances of these wells can be considerably improved using a simple well stimulation technique. (J.S.). 1 fig

  19. Aircraft Corrosion

    Science.gov (United States)

    1981-08-01

    attribud au choix de traitements et de rev~tements spproprids. Au contrairo, dens d’sutros structures des corrosions iirportsntea se sont msnifestdes...au traitement . micaniqus qui provoque une compression de surface - h1l’spplication i1’une double protection comportant oxydation snodique et...chlore mais dans une proportion semblable b cells d’une eau de vil)e ; - lea solides, d’aprbs lea analyses chimique et criatallographique, paraissaiont

  20. Corrosion Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Corrosion Testing Facility is part of the Army Corrosion Office (ACO). It is a fully functional atmospheric exposure site, called the Corrosion Instrumented Test...

  1. Introduction to the reliability study of IGBT switching cells under strong constraints; Introduction a l'etude de la fiabilite des cellules de commutation a IGBT sous fortes contraintes

    Energy Technology Data Exchange (ETDEWEB)

    Vallon, J.

    2003-12-15

    The reliability approach in power electronics is a complex problem including the coupling of current / voltage surges, physical and technological imperfections, from the die to the power circuit. First of all, we define a methodology based on the monitoring of a great number of components, during a long time campaign. Components are 600 V-50 A-20 kHz IGBT-diodes modules working in PWM inverter cells owing to an original opposition method. An exhaustive study of cell-switching failure modes allowed us to design a suitable and efficient protection. Afterwards, a complete reliability test bench was carried out with electrical and thermal monitoring. A preliminary screening protocol was also applied. The first results are presented in this thesis. (author)

  2. Développement urbain fractal sous contraintes d'accessibilités - Modèles et outils d'aide à la décision pour l'aménagement urbain

    OpenAIRE

    Frankhauser , Pierre; Tannier , Cécile; Houot , Hélène; Vuidel , Gilles

    2010-01-01

    77; Ce projet fait suite à une recherche financée par le PREDIT intitulée " Vers des déplacements périurbains plus durables - Proposition de modèles fractals opérationnels d'urbanisation " (Dir. P. Frankhauser - Participants : H. Houot, C. Tannier et G. Vuidel)1. Ce premier projet, réalisé entre juillet 2005 et juin 2007, a posé les bases du présent projet, à savoir la définition de ses fondements conceptuels et de ses principes méthodologiques. Le présent projet a pour but de compléter la mé...

  3. Study and simulation of a multi-lithology stratigraphic model under maximum erosion rate constraint; Etude et simulation d'un modele statigraphique multi-lithologique sous contrainte de taux d'erosion maximal

    Energy Technology Data Exchange (ETDEWEB)

    Gervais, V.

    2004-11-01

    The subject of this report is the study and simulation of a model describing the infill of sedimentary basins on large scales in time and space. It simulates the evolution through time of the sediment layer in terms of geometry and rock properties. A parabolic equation is coupled to an hyperbolic equation by an input boundary condition at the top of the basin. The model also considers a unilaterality constraint on the erosion rate. In the first part of the report, the mathematical model is described and particular solutions are defined. The second part deals with the definition of numerical schemes and the simulation of the model. In the first chap-ter, finite volume numerical schemes are defined and studied. The Newton algorithm adapted to the unilateral constraint used to solve the schemes is given, followed by numerical results in terms of performance and accuracy. In the second chapter, a preconditioning strategy to solve the linear system by an iterative solver at each Newton iteration is defined, and numerical results are given. In the last part, a simplified model is considered in which a variable is decoupled from the other unknowns and satisfies a parabolic equation. A weak formulation is defined for the remaining coupled equations, for which the existence of a unique solution is obtained. The proof uses the convergence of a numerical scheme. (author)

  4. Corrosion of beryllium oxide; Corrosion de l'oxyde de beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Elston, J; Caillat, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Data are reported on the volatilization rate of beryllium oxide in moist air depending on temperature and water vapour concentration. They are concerned with powder samples or sintered shapes of various densities. For sintered samples, the volatilization rate is very low under the following conditions: - temperature: 1300 deg. C, - water vapour concentration in moist air: 25 g/m{sup 3}, - flow rate: 12 I/hour corresponding to a speed of 40 m/hour on the surface of the sample. For calcinated powders (1300 deg. C), grain growth has been observed under a stream of moist air at 1100 deg. C. For instance, grain size changes from 0,5 to at least 2 microns after 500 hours of exposure at this temperature. Furthermore, results data are reported on corrosion of sintered beryllium oxide in pressurized water. At 250 deg. C, under a pressure of 40 kg/cm{sup 2} water is very slightly corrosive; however, internal strains are revealed. Finally, some features on the corrosion in liquid sodium are exposed. (author)Fren. [French] La volatilisation de l'oxyde de beryllium dans l'air humide est etudiee en fonction de la temperature pour differentes teneurs de vapeur d'eau. Les essais decrits portent sur de l'oxyde de beryllium en poudre ou sur des echantillons d'oxyde de beryllium fritte de differentes densites. Avec un debit d'air de 12 I/h contenant 25 g de vapeur par m{sup 3} correspondant a une vitesse de 40 m/h sur la surface de l'echantillon, la volatilisation des frittes a 1300 deg. C reste tres faible. Sur de la poudre d'oxyde de beryllium calcinee initialement a 1300 deg. C, on observe un grossissement de la taille des grains sous l'influence de l'air humide a 1100 deg. C. Par exemple, elle passe de 0,5 a au moins 2 microns apres 500 heures d'exposition a cette temperature. On donne d'autre part les resultats d'une etude de la corrosion de frittes d'oxyde de beryllium par l'eau, en autoclave. A 250 deg. C, sous une pression de 40 kg/cm{sup 2}, l'action de l'eau reste tres

  5. Al-Ḥudayyda sous occupation ottomane (1849-1918

    Directory of Open Access Journals (Sweden)

    Patrice Chevalier

    2011-12-01

    Full Text Available Petit port de pêche situé sur les côtes de la mer Rouge, al-Ḥudayyda change progressivement de statut et de dimensions avec l’arrivée de l’armée ottomane en 1839. Al-Ḥudayyda se voit alors choisi comme l’un des points stratégiques (militaire et politique du dispositif colonial ottoman.Grâce aux différentes infrastructures mises en place par l’administration ottomane, mais aussi grâce à l’ouverture du canal de Suez en 1869, le village attire peu à peu une population multi-ethnique et cosmopolite venue y commercer ou simplement y trouver refuge, dans un contexte politique régional passablement agité. D’une centaine de Yéménites à l’origine, il compte 42 000 âmes à la veille de la première guerre mondiale.La cohabitation sous administration ottomane va-t-elle générer ou non des échanges ou emprunts entre les différentes communautés ? Les Ottomans vont-ils réussir à transcender les multiples appartenances identitaires au profit d’une appartenance citoyenne à l’empire, comme le prévoit leur ambitieux programme de réformes ? La ville d’al- Ḥudayyda sera-t-elle dotée d’une identité spécifique suffisamment forte pour que les individus appartenant aux différentes communautés présentes s’identifient à la ville ? Voilà quelques-unes des questions auxquelles cet article tente de répondre.

  6. Corrosion technology. V. 1

    International Nuclear Information System (INIS)

    Khan, I.H.

    1989-01-01

    This book has been produced for dissemination of information on corrosion technology, corrosion hazards and its control. Chapter one of this book presents an overall view of the subject and chapter 2-5 deals with electrochemical basics, types of corrosion, pourbaix diagrams and form of corrosion. The author explains polarization/kinetics of corrosion, passivity, aqueous corrosion and corrosion testing and monitoring in 6-11 chapters. The author hopes it will provide incentive to all those interested in the corrosion technology. (A.B.)

  7. Corrosion/94 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    The approximately 500 papers from this conference are divided into the following sections: Rail transit systems--stray current corrosion problems and control; Total quality in the coatings industry; Deterioration mechanisms of alloys at high temperatures--prevention and remediation; Research needs and new developments in oxygen scavengers; Computers in corrosion control--knowledge based system; Corrosion and corrosivity sensors; Corrosion and corrosion control of steel reinforced concrete structures; Microbiologically influenced corrosion; Practical applications in mitigating CO 2 corrosion; Mineral scale deposit control in oilfield-related operations; Corrosion of materials in nuclear systems; Testing nonmetallics for life prediction; Refinery industry corrosion; Underground corrosion control; Mechanisms and applications of deposit and scale control additives; Corrosion in power transmission and distribution systems; Corrosion inhibitor testing and field application in oil and gas systems; Decontamination technology; Ozone in cooling water applications, testing, and mechanisms; Corrosion of water and sewage treatment, collection, and distribution systems; Environmental cracking of materials; Metallurgy of oil and gas field equipment; Corrosion measurement technology; Duplex stainless steels in the chemical process industries; Corrosion in the pulp and paper industry; Advances in cooling water treatment; Marine corrosion; Performance of materials in environments applicable to fossil energy systems; Environmental degradation of and methods of protection for military and aerospace materials; Rail equipment corrosion; Cathodic protection in natural waters; Characterization of air pollution control system environments; and Deposit-related problems in industrial boilers. Papers have been processed separately for inclusion on the data base

  8. Machine for extrusion under vacuum; Machine de fluage sous vide

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In a study of the behaviour of easily oxidised metals during the extrusion process, it is first necessary to find an effective mean of fighting corrosion, since this, even when barely detectable, has an important influence on the validity of the results recorded. The neatest and also the most efficient of all the methods tried consists in creating a vacuum around the test piece. Working on this principle, and at the same time respecting the conventional rules for extrusion tests (loading the sample after stabilisation at the testing temperature, differential measurements of lengthening, etc.) we found it necessary to construct an original machine. (author) [French] L'etude du comportement au fluage des materiaux facilement oxydables exige, en premier lieu, une lutte efficace contre la corrosion qui, meme a peine decelable, prend une part preponderante quant a la validite des resultats enregistres. La solution la plus elegante, et, a vrai dire, la plus energique parmi toutes les methodes essayees, consiste a realiser le vide autour de l'eprouvette d'essai. Partant de ce principe, et pour sauvegarder les regles classiques de l'essai de fluage (mise en charge de l'eprouvette apres stabilisation en temperature d'essai, mesures differentielles des allongements, etc.) nous nous sommes trouves dans la necessite de construire une machine inedite. (auteur)

  9. Machine for extrusion under vacuum; Machine de fluage sous vide

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In a study of the behaviour of easily oxidised metals during the extrusion process, it is first necessary to find an effective mean of fighting corrosion, since this, even when barely detectable, has an important influence on the validity of the results recorded. The neatest and also the most efficient of all the methods tried consists in creating a vacuum around the test piece. Working on this principle, and at the same time respecting the conventional rules for extrusion tests (loading the sample after stabilisation at the testing temperature, differential measurements of lengthening, etc.) we found it necessary to construct an original machine. (author) [French] L'etude du comportement au fluage des materiaux facilement oxydables exige, en premier lieu, une lutte efficace contre la corrosion qui, meme a peine decelable, prend une part preponderante quant a la validite des resultats enregistres. La solution la plus elegante, et, a vrai dire, la plus energique parmi toutes les methodes essayees, consiste a realiser le vide autour de l'eprouvette d'essai. Partant de ce principe, et pour sauvegarder les regles classiques de l'essai de fluage (mise en charge de l'eprouvette apres stabilisation en temperature d'essai, mesures differentielles des allongements, etc.) nous nous sommes trouves dans la necessite de construire une machine inedite. (auteur)

  10. Accelerated Corrosion Testing

    Science.gov (United States)

    1982-12-01

    Treaty Organization, Brussels, 1971), p. 449. 14. D. 0. Sprowls, T. J. Summerson, G. M. Ugianski, S. G. Epstein, and H. L. Craig , Jr., in Stress...National Association of Corrosion Engineers Houston, TX, 1972). 22. H. L. Craig , Jr. (ed.), Stress Corrosion-New Approaches, ASTM-STP- 610 (American...62. M. Hishida and H. Nakada, Corrosion 33 (11) 403 (1977). b3. D. C. Deegan and B. E. Wilde, Corrosion 34 (6), 19 (1978). 64. S. Orman, Corrosion Sci

  11. Methods for determining thermal stresses values. Some examples relating to nuclear reactors; Methodes de determination des contraintes thermiques. Quelques exemples d'application aux reacteurs

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J; Gautier, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Peres, A [Israel Institute of Technology, Dept. of Nuclear Science Technion (Israel)

    1958-07-01

    As modern techniques develop more elaborate machines, and make their way towards higher and higher temperatures and pressures, the thermal stresses become a matter of major importance in the design of mechanical structures. In the first part of this paper, the authors examine the problem from a theoretical standpoint, and try to evaluate the aptitude and limitation of mathematical techniques to attain the quantitative values of thermal stresses. This paper deals mainly with the experimental methods to measure thermal stresses. The authors show some examples relating to nuclear reactors. (author)Fren. [French] Au fur et a mesure que la technique moderne developpe des machines plus poussees et s'oriente vers des temperatures et des pressions toujours plus elevees, les contraintes thermiques deviennent un facteur d'importance capitale dans le calcul des structures mecaniques. Les auteurs examinent d'abord l'aspect theorique du probleme, ainsi que l'aptitude et les limites du calcul pour exprimer quantitativement la valeur des contraintes thermiques. Les auteurs exposent principalement, ensuite, les methodes experimentales qui permettent de mesurer ces contraintes, et illustrent cet expose de quelques exemples relatifs aux installations nucleaires. (auteur)

  12. Corrosion/96 conference papers

    International Nuclear Information System (INIS)

    Anon.

    1996-01-01

    Topics covered by this conference include: cathodic protection in natural waters; cleaning and repassivation of building HVAC systems; worldwide opportunities in flue gas desulfurization; advancements in materials technology for use in oil and gas service; fossil fuel combustion and conversion; technology of corrosion inhibitors; computers in corrosion control--modeling and information processing; recent experiences and advances of austenitic alloys; managing corrosion with plastics; corrosion measurement technology; corrosion inhibitors for concrete; refining industry; advances in corrosion control for rail and tank trailer equipment; CO 2 corrosion--mechanisms and control; microbiologically influenced corrosion; corrosion in nuclear systems; role of corrosion in boiler failures; effects of water reuse on monitoring and control technology in cooling water applications; methods and mechanisms of scale and deposit control; corrosion detection in petroleum production lines; underground corrosion control; environmental cracking--relating laboratory results and field behavior; corrosion control in reinforced concrete structures; corrosion and its control in aerospace and military hardware; injection and process addition facilities; progress reports on the results of reinspection of deaerators inspected or repaired per RP0590 criteria; near 100% volume solids coating technology and application methods; materials performance in high temperature environments containing halides; impact of toxicity studies on use of corrosion/scale inhibitors; mineral scale deposit control in oilfield related operations; corrosion in gas treating; marine corrosion; cold climate corrosion; corrosion in the pulp and paper industry; gaseous chlorine alternatives in cooling water systems; practical applications of ozone in recirculating cooling water systems; and water reuse in industry. Over 400 papers from this conference have been processed separately for inclusion on the data base

  13. Development of Pangasius steaks by improved sous-vide technology and its process optimization.

    Science.gov (United States)

    Kumari, Namita; Singh, Chongtham Baru; Kumar, Raushan; Martin Xavier, K A; Lekshmi, Manjusha; Venkateshwarlu, Gudipati; Balange, Amjad K

    2016-11-01

    The present study embarked on the objective of optimizing improved sous - vide processing condition for development of ready-to-cook Pangasius steaks with extended shelf-life using response surface methodology. For the development of improved sous - vide cooked product, Pangasius steaks were treated with additional hurdles in various combinations for optimization. Based on the study, suitable combination of chitosan and spices was selected which enhanced antimicrobial and oxidative stability of the product. The Box-Behnken experimental design with 15 trials per model was adopted for designing the experiment to know the effect of independent variables, namely chitosan concentration (X 1 ), cooking time (X 2 ) and cooking temperature (X 3 ) on dependent variable i.e. TBARS value (Y 1 ). From RSM generated model, the optimum condition for sous - vide processing of Pangasius steaks were 1.08% chitosan concentration, 70.93 °C of cooking temperature and 16.48 min for cooking time and predicted minimum value of multiple response optimal condition was Y = 0.855 mg MDA/Kg of fish. The high correlation coefficient (R 2  = 0.975) between the model and the experimental data showed that the model was able to efficiently predict processing condition for development of sous - vide processed Pangasius steaks. This research may help the processing industries and Pangasius fish farmer as it provides an alternative low cost technology for the proper utilization of Pangasius .

  14. Catastrophes caused by corrosion

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    For many years, huge attention has been paid to the problem of corrosion damage and destruction of metallic materials. Experience shows that failures due to corrosion problems are very important, and statistics at the world level shows that the damage resulting from the effects of various forms of corrosion is substantial and that, for example, in industrialized countries it reaches 4-5% of national incomes. Significant funds are determined annually for the prevention and control of corrosion...

  15. Modelling of Corrosion Cracks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed.......Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed....

  16. Oxidation of iron and steels by carbon dioxide under pressure (1962); Oxydation du fer et des aciers par l'anhydride carbonique sous pression (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Colombie, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    After having developed one of the first thermo-balances to operate under pressure, we have studied the influence of the pressure on the corrosion of iron and steels by carbon dioxide. The corrosion was followed by three different methods simultaneously: by the oxidation kinetics, by micrographs, and by radiocrystallography. We have been able to show that the influence of the pressure is not negligible and we have provided much experimental evidence: oxidation kinetics, micrographic aspects, surface precipitation of carbon, metal carburization, the texture of the magnetite layer. All these phenomena are certainly modified by changes in the carbon dioxide pressure. In order to interpret most of our results we have been led to believe that the phenomenon of corrosion by CO{sub 2} depends on secondary reactions localised at the oxide-gas interface. This would constitute a major difference between the oxidation by CO{sub 2} and that by oxygen. (author) [French] Apres avoir etudie et mis au point une des premieres thermobalances fonctionnant sous pression, nous avons etudie l'influence de la pression sur la corrosion du fer et des aciers par l'anhydride carbonique. Notre etude a ete conduite simultanement sur trois plans differents: etude des cinetiques d'oxydation, etude micrographique et etude radiocristallographique. Nous avons pu montrer que l'influence de la pression n'etait pas negligeable et nous en avons fourni un faisceau de preuves experimentales important: cinetiques d'oxydation, aspect micrographique, precipitation superficielle de carbone, carburation du metal, texture de la couche de magnetite. Tous ces phenomenes sont sans aucun doute modifies par une variation de pression du gaz carbonique. Pour interpreter la plupart de nos resultats, nous avons ete conduits a penser que le phenomene de corrosion par CO{sub 2} etait tributaire de reactions secondaires localisees a l'interface oxyde-gaz. Ce serait la une des differences fondamentales entre l'oxydation par

  17. Erosion-corrosion

    International Nuclear Information System (INIS)

    Aghili, B.

    1999-05-01

    A literature study on erosion-corrosion of pipings in the nuclear industry was performed. Occurred incidents are reviewed, and the mechanism driving the erosion-corrosion is described. Factors that influence the effect in negative or positive direction are treated, as well as programs for control and inspection. Finally, examples of failures from databases on erosion-corrosion are given in an attachment

  18. Microbiological corrosion of metals

    International Nuclear Information System (INIS)

    Vladislavlev, V.V.

    1992-01-01

    Problems is considered of development of the microbiological corrosion of the NPP equipment. The main attention is paid to the selective character of microbiological corrosion in zones of welded joints of austenitic steels. It is noted that the presence of technological defects promotes growth of corrosional damages. Methods for microbiological corrosion protection are discussed

  19. Management of Reinforcement Corrosion

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Møller, Per

    Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management...... of reinforcement corrosion....

  20. Corrosion of metallic materials. Dry corrosion, aqueous corrosion and corrosion by liquid metal, methods of protection

    International Nuclear Information System (INIS)

    Helie, Max

    2015-01-01

    This book is based on a course on materials given in an engineering school. The author first gives an overview of metallurgy issues: metallic materials (pure metals, metallic alloys), defects of crystal lattices (point defects, linear defects or dislocations), equilibrium diagrams, steels and cast, thermal processing of steels, stainless steels, aluminium and its alloys, copper and its alloys. The second part addresses the properties and characterization of surfaces and interfaces: singularity of a metal surface, surface energy of a metal, energy of grain boundaries, adsorption at a material surface, metal-electrolyte interface, surface oxide-electrolyte interface, techniques of surface analysis. The third chapter addresses the electrochemical aspects of corrosion: description of the corrosion phenomenon, free enthalpy of a compound and free enthalpy of a reaction, case of dry corrosion (thermodynamic aspect, Ellingham diagram, oxidation mechanisms, experimental study, macroscopic modelling), case of aqueous corrosion (electrochemical thermodynamics and kinetics, experimental determination of corrosion rate). The fourth part addresses the different forms of aqueous corrosion: generalized corrosion (atmospheric corrosion, mechanisms and tests), localized corrosion (galvanic, pitting, cracking, intergranular, erosion and cavitation), particular cases of stress cracking (stress corrosion, fatigue-corrosion, embrittlement by hydrogen), and bi-corrosion (of non alloyed steels, of stainless steels, and of aluminium and copper alloys). The sixth chapter addresses the struggle and the protection against aqueous corrosion: methods of prevention, scope of use of main alloys, geometry-based protection of pieces, use of corrosion inhibitors, use of organic or metallic coatings, electrochemical protection. The last chapter proposes an overview of corrosion types in industrial practices: in the automotive industry, in the oil industry, in the aircraft industry, and in the

  1. Fighting corrosion in India

    Energy Technology Data Exchange (ETDEWEB)

    Rajagopalan, K S; Rangaswamy, N S

    1979-03-01

    A survey covers the cost of corrosion in India; methods of preventing corrosion in industrial plants; some case histories, including the prevention of corrosion in pipes through which fuels are pumped to storage and the stress-corrosion cracking of evaporators in fertilizer plants; estimates of the increase in demand in 1979-89 for anticorrosion products and processes developed by the Central Electrochemical Research Institute (CECRI) at Karaikudi, India; industries that may face corrosion problems requiring assistance from CECRI, including the light and heavy engineering structural, and transport industries and the chemical industry; and some areas identified for major efforts, including the establishment of a Corrosion Advisory Board with regional centers and the expansion of the Tropical Corrosion Testing Station at Mandapam Camp, Tamil Nadu.

  2. Une localisation exceptionnelle de la tuberculose vertébrale Mal de Pott sous-occipital

    Science.gov (United States)

    Yahyaoui, Sana; Majdoub, Senda; Zaghouani, Houneida; Fradj, Hosni Ben; Bakir, Dejla; Bouajina, Elyes; Kraiem, Chakib

    2013-01-01

    Le mal de Pott est la forme la plus commune de la tuberculose osseuse touchant essentiellement le rachis dorso-lombaire. La localisation sous-occipitale reste exceptionnelle. Le diagnostic de cette entité est le plus souvent tardif ce qui expose à des complications graves. Les radiographies standard ne sont parlantes qu’à un stade tardif de la maladie, d'où l'intérêt de l'imagerie moderne notamment la tomodensitométrie (TDM) et l'imagerie par résonance magnétique (IRM) qui permettent un diagnostic précoce. Nous rapportons un nouveau cas de tuberculose sous-occipitale. Le diagnostic était posé sur l'imagerie en coupe et confirmé histologiquement à la biopsie transorale. Sont rappelés les aspects en imagerie de cette localisation particulière du mal de Pott. PMID:23819005

  3. Spécificités du sous-titrage pour enfants malentendants

    OpenAIRE

    Comitre-Narvaez, Isabel

    2016-01-01

    Ce travail aborde la spécificité multisémiotique du texte audiovisuel qui est à l’origine de nombreux défis que le traducteur audiovisuel doit relever. Il explore les rapports intersémiotiques qui s’établissent entre le code verbal et le code visuel et se concentre sur les particularités du sous-titrage pour sourds et malentendants dans la “compensation” du déficit auditif, essentiellement son rapport spécifique à l’image. À cet égard, Gottlieb signale que le succès du sous-titrage dépend du ...

  4. Profil lipidique des personnes vivant avec le VIH sous antirétroviral ...

    African Journals Online (AJOL)

    Au regard des connaissances actuelles, aucune étude n'est disponible au Bénin sur le profil lipidique des personnes vivant avec le VIH. L'objectif de la présente étude est de décrire le profil lipidique des personnes vivant avec le VIH sous antirétroviral suivies au CHU-O/P de Porto-Novo. Il s'est agi d'une étude ...

  5. statut de la matiere organique des cambisols et des lixisols sous

    African Journals Online (AJOL)

    Administrateur

    L'étude vise à évaluer la matière organique des Cambisols et des Lixisols sous formations naturelles de longue durée en zone climatique nord-soudanienne et à établir, les relations entre ... sont supérieures à celles des sols des zones sahélienne et sud-soudanienne. ... globale a eu une corrélation positive avec le pH.

  6. Volatile compound profile of sous-vide cooked lamb loins at different temperature-time combinations.

    Science.gov (United States)

    Roldán, Mar; Ruiz, Jorge; Del Pulgar, José Sánchez; Pérez-Palacios, Trinidad; Antequera, Teresa

    2015-02-01

    Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60 and 80°C) and time (6 and 24h) to assess the effect on the volatile compound profile. Major chemical families in cooked samples were aliphatic hydrocarbons and aldehydes. The volatile compound profile in sous-vide cooked lamb loin was affected by the cooking temperature and time. Volatile compounds arising from lipid oxidation presented a high abundance in samples cooked at low or moderate cooking conditions (60°C for 6 and 24h, 80°C for 6h), while a more intense time and temperature combination (80°C for 24h) resulted on a higher concentration of volatile compounds arising from Strecker degradations of amino acids, as 2-methylpropanal and 3-methylbutanal. Therefore, sous-vide cooking at moderately high temperatures for long times would result in the formation of a stronger meaty flavor and roast notes in lamb meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Influence de la protection cathodique sur le comportement électrochimique des couches de corrosion d'acier au carbone

    OpenAIRE

    Tran Tron Long , Mai; Sutter , Eliane; Tribollet , Bernard

    2013-01-01

    11 pages, www.mattech-journal.org; International audience; Les propriétés électrochimiques de la couche de dépôts de corrosion formée à la surface des coupons d'acier E24 immergés pendant plusieurs années dans l'eau de mer sous différentes conditions de protection cathodique ont éteé'tudiées à l'aide de la spectroscopie d'impédance électrochimique et de mesures globale et locale de courant. Les résultats obtenus montrent que la couche de dépôts dont le comportement est déterminé par sa sous-c...

  8. Corrosion principles and surface modification

    International Nuclear Information System (INIS)

    Kruger, J.

    1982-01-01

    This chapter examines the important strategies provided by the newer ideas of corrosion science and engineering that surface modification techniques must utilize to help prevent corrosion, especially the most damaging kind of aqueous corrosion, localized corrosion. Provides a brief introduction to the principles underlying the phenomenon of corrosion in order to use them to discuss surface modification strategies to combat corrosion. Discusses the electrochemistry of corrosion; the thermodynamics of corrosion; the kinetics of corrosion; thermodynamic strategies; and kinetic strategies (formation of more protective passive films; resistance to breakdown; ductility; repassivation)

  9. Compatibility of various magnesium alloys with pressurized carbon dioxide at high temperatures; Compatibilite de divers alliages de magnesium avec le gaz carbonique sous pression aux temperatures elevees

    Energy Technology Data Exchange (ETDEWEB)

    Dewanckel, B; David, R; Hulin, C; Leclercq, D [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

    1968-07-01

    This work on the compatibility of magnesium alloys with pressurized carbon dioxide has been carried out along three lines: - testing of special alloys containing additions of zirconium, manganese, cerium, zinc, beryllium and yttrium. The results are satisfactory, generally speaking, and the corrosion kinetics are often comparable to those of conventional magnesium-zirconium alloy; - influence of the quality of the carbon dioxide, in particular the presence of water vapour or of carbon monoxide in this gas. It appears that oxidation is reduced if the carbon dioxide contains traces of water vapour, but is more pronounced if carbon monoxide is also present; - study of certain phenomena related to corrosion: size changes in the samples during tests, structural modifications in the alloys (grain-size changes, formation of a cortical zone in the case of alloys containing zirconium). The influence of thermal cycling has also been studied in a few specific tests. The results obtained make it possible to compare the behaviour of various alloys under varying conditions of long-term use, and to choose, if required, the best composition for a given application. (authors) [French] Ce travail sur la compatibilite des alliages de magnesium avec le gaz carbonique sous pression a ete particulierement oriente dans trois directions: - epreuve, d'alliages speciaux comportant des additions de zirconium, manganese, cerium, zinc, beryllium et yttrium. Les resultats sont generalement satisfaisants et les cinetiques de corrosion souvent comparables a celles de l'alliage magnesium-zirconium classique; - influence de la qualite du gaz carbonique, et notamment de la presence de vapeur d'eau ou d'oxyde de carbone dans ce gaz. Il est apparu que l'oxydation est reduite si le gaz carbonique contient des traces d'eau, mais accrue si l'oxyde de carbone est egalement present; - etude de certains phenomenes lies a la corrosion: variations dimensionnelles des echantillons au cours des essais

  10. Monitoring Microbially Influenced Corrosion

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    and diffusional effects and unreliable corrosion rates, when biofilm and ferrous sulphide corrosion products cover the steel surface. Corrosion rates can be overestimated by a factor of 10 to 100 by electrochemical techniques. Weight loss coupons and ER are recommended as necessary basic monitoring techniques......Abstract Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria (SRB). The applicability and reliability of a number of corrosion monitoring techniques for monitoring MIC has been evaluated in experiments....... EIS might be used for detection of MIC as the appearance of very large capacitances can be attributed to the combined ferrous sulphide and biofilm formation. Capacitance correlates directly with sulphide concentration in sterile sulphide media. Keywords: Corrosion monitoring, carbon steel, MIC, SRB...

  11. SRB seawater corrosion project

    Science.gov (United States)

    Bozack, M. J.

    1991-01-01

    The corrosion behavior of 2219 aluminum when exposed to seawater was characterized. Controlled corrosion experiments at three different temperatures (30, 60 and 100 C) and two different environments (seawater and 3.5 percent salt solution) were designed to elucidate the initial stages in the corrosion process. It was found that 2219 aluminum is an active catalytic surface for growth of Al2O3, NaCl, and MgO. Formation of Al2O3 is favored at lower temperatures, while MgO is favored at higher temperatures. Visible corrosion products are formed within 30 minutes after seawater exposure. Corrosion characteristics in 3.5 percent salt solution are different than corrosion in seawater. Techniques utilized were: (1) scanning electron microscopy, (2) energy dispersive x-ray spectroscopy, and (3) Auger electron spectroscopy.

  12. Microbiological and other characteristics of chicken breast meat following electron-beam and sous-vide treatments

    International Nuclear Information System (INIS)

    Shamsuzzaman, K.; Chuaqui-Offermanns, N.; Lucht, L.; McDougall, T.; Borsa, J.

    1992-01-01

    The combined effects of radiation and sous-vide treatment of chicken breast meat were investigated with respect to survival and growth of Listeria monocytogenes, shelf life, thiamine content, and sensory qualities. Chicken breasts were inoculated with L. monocytogenes 81-861 (10(5) CFU/G), vacuum-packed, irradiated with electron beam (EB) up to 2.9 kGy, and cooked to an internal temperature of 65.6 degrees C. Sous-vide treatment alone had marginal lethal effect on the L. monocytogenes; the residual inoculum reached 10(7) CFU/g after 8 weeks at 2 degrees C. However, after the combined treatments of sous-vide and EB at 2.9 kGy, the organism remained undetectable during the 8-week storage period. Parallel studies on uninoculated breast meat revealed that sous-vide samples had a shelf life of less than 6 weeks without EB treatment, whereas samples that were irradiated and then received sous-vide treatment had a shelf life of at least 8 weeks. There was a slight reduction in thiamine levels as a result of the EB treatment, but there was essentially no additional loss of thiamine due to the subsequent sous-vide treatment and storage at 2 degrees C. Electron-beam treatment had very little effect on the odor and flavor of the reheated samples. It was concluded that EB treatment combined with, sous-vide treatment can greatly enhance the microbial safety and shelf life of chicken breast meat

  13. Corrosion control. 2. ed.

    International Nuclear Information System (INIS)

    Bradford, S.A.

    2001-01-01

    The purpose of this text is to train engineers and technologists not just to understand corrosion but to control it. Materials selection, coatings, chemical inhibitors, cathodic and anodic protection, and equipment design are covered in separate chapters. High-temperature oxidation is discussed in the final two chapters ne on oxidation theory and one on controlling oxidation by alloying and with coatings. This book treats corrosion and high-temperature oxidation separately. Corrosion is divided into three groups: (1) chemical dissolution including uniform attack, (2) electrochemical corrosion from either metallurgical or environmental cells, and (3) stress-assisted corrosion. Corrosion is logically grouped according to mechanisms rather than arbitrarily separated into different types of corrosion as if they were unrelated. For those university students and industry personnel who approach corrosion theory very hesitantly, this text will present the electrochemical reactions responsible for corrosion summed up in only five simple half-cell reactions. When these are combined on a polarization diagram, which is also explained in detail, the electrochemical processes become obvious. For those who want a text stripped bare of electrochemical theory, several noted sections can be omitted without loss of continuity. However, the author has presented the material in such a manner that these sections are not beyond the abilities of any high school graduate who is interested in technology

  14. Coatings and Corrosion Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The mission of the Coatings and Corrosion Laboratory is to develop and analyze the effectiveness of innovative coatings test procedures while evaluating the...

  15. Corrosion in the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Brondel, D [Sedco Forex, Montrouge (France); Edwards, R [Schlumberger Well Services, Columbus, OH (United States); Hayman, A [Etudes et Productions Schlumberger, Clamart (France); Hill, D [Schlumberger Dowell, Tulsa, OK (United States); Mehta, S [Schlumberger Dowell, St. Austell (United Kingdom); Semerad, T [Mobil Oil Indonesia, Inc., Sumatra (Indonesia)

    1994-04-01

    Corrosion costs the oil industry billions of dollars a year, a fact that makes the role of the corrosion engineer an increasingly important one. Attention is paid to how corrosion affects every aspect of exploration and production, from offshore rigs to casing. Also the role of corrosion agents such as drilling and production fluids is reviewed. Methods of control and techniques to monitor corrosion are discussed, along with an explanation of the chemical causes of corrosion. 21 figs., 32 refs.

  16. Determination of stresses in a sheath connected to a rod; Determination des contraintes dans une gaine liee a un barreau

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, J L; Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    gaine, toujours astreinte a suivre les dilatations du barreau, va re le siege de contraintes. C'est a la determination de celles-ci que vise la presente etude. (auteur)

  17. Corrosion evaluation technology

    International Nuclear Information System (INIS)

    Kim, Uh Chul; Han, Jeong Ho; Nho, Kye Ho; Lee, Eun Hee; Kim, Hong Pyo; Hwang, Seong Sik; Lee, Deok Hyun; Hur, Do Haeng; Kim, Kyung Mo.

    1997-09-01

    A multifrequency ACPD system was assembled which can measure very small crack. Stress corrosion cracking test system with SSRT operating high temperature was installed. Stress corrosion cracking test of newly developed alloy 600 and existing alloy 600 was carried out in steam atmosphere of 400 deg C. No crack was observed in both materials within a test period of 2,000 hrs. Corrosion fatigue test system operating at high temperature was installed in which fatigue crack was measured by CDPD. Lead enhanced the SCC of the Alloy 600 in high temperature water, had a tendency to modify a cracking morphology from intergranular to transgranular. Pit initiation preferentially occurred at Ti-rich carbide. Resistance to pit initiation decreased with increasing temperature up to 300 deg C. Test loop for erosion corrosion was designed and fabricated. Thin layer activation technique was very effective in measuring erosion corrosion. Erosion corrosion of a part of secondary side pipe was evaluated by the Check Family Codes of EPRI. Calculated values of pipe thickness by Check Family Codes coincided with the pipe thickness measured by UT with an error of ± 20%. Literature review on turbine failure showed that failure usually occurred in low pressure turbine rotor disc and causes of failure are stress corrosion cracking and corrosion fatigue. (author). 12 refs., 20 tabs., 77 figs

  18. Aluminum Corrosion and Turbidity

    International Nuclear Information System (INIS)

    Longtin, F.B.

    2003-01-01

    Aluminum corrosion and turbidity formation in reactors correlate with fuel sheath temperature. To further substantiate this correlation, discharged fuel elements from R-3, P-2 and K-2 cycles were examined for extent of corrosion and evidence of breaking off of the oxide film. This report discusses this study

  19. Demystifying Controlling Copper Corrosion

    Science.gov (United States)

    The LCR systematically misses the highest health and corrosion risk sites for copper. Additionally, there are growing concerns for WWTP copper in sludges and discharge levels. There are many corrosion control differences between copper and lead. This talk explains the sometimes c...

  20. Archaeological analogs and corrosion

    International Nuclear Information System (INIS)

    David, D.

    2008-01-01

    In the framework of the high level and long life radioactive wastes disposal deep underground, the ANDRA built a research program on the material corrosion. In particular they aim to design containers for a very long time storage. Laboratory experiments are in progress and can be completed by the analysis of metallic archaeological objects and their corrosion after hundred years. (A.L.B.)

  1. Thermograms of the combined High Hydrostatic Pressure and Sous-vide treated Longissimus dorsi of pork

    Science.gov (United States)

    Kenesei, Gy; Jónás, G.; Salamon, B.; Dalmadi, I.

    2017-10-01

    In this work, slices of Longissimus dorsi of pork was used as raw material to establish the effects of the sous-vide technology and the high hydrostatic pressure treatments (and their combinations) on meat. The state of the proteins in meat has a very important effect on several quality parameters of the product, such as weight loss, water holding capacity, organoleptic properties. Therefore it is important to follow and analyse the denaturation of the protein content during food processing. The samples were cooked sous-vide (60 °C, 5-480 minutes) or pressurized (100-600 MPa, 5 minutes, room temperature). Also two steps treatments were studied combining both technologies, applying high hydrostatic pressure treatment (300 or 600 MPa, 5 minutes, room temperature) after or previous to sous-vide cooking (60 °C, 30 minutes). The changes in the condition of meat proteins were followed by a differential scanning calorimeter. The DSC curves were analysed using the unit’s own software where denaturation heat was determined. Thermograms show through the change of the sample’s protein state the dissimilar effect of the treatments. Using the Polar Qualification System -previously proved to be effective with NIR measurements- the spectral information was reduced to a two dimensional polar co-ordinate system where each DSC curve is represented by a “quality point”. As a new experiment the applied PQS data reduction method compared to the traditional thermal analysis data processing gave us less information on the differences of our samples although the results are promising as we were able to detect the same trends and characteristics.

  2. Erosion and erosion-corrosion

    International Nuclear Information System (INIS)

    Isomoto, Yoshinori

    2008-01-01

    It is very difficult to interpret the technical term of erosion-corrosion' which is sometimes encountered in piping systems of power plants, because of complicated mechanisms and several confusing definitions of erosion-corrosion phenomena. 'FAC (flow accelerated corrosion)' is recently introduced as wall thinning of materials in power plant systems, as a representative of 'erosion-corrosion'. FAC is, however, not necessarily well understood and compared with erosion-corrosion. This paper describes firstly the origin, definition and fundamental understandings of erosion and erosion-corrosion, in order to reconsider and reconfirm the phenomena of erosion, erosion-corrosion and FAC. Next, typical mapping of erosion, corrosion, erosion-corrosion and FAC are introduced in flow velocity and environmental corrosiveness axes. The concept of damage rate in erosion-corrosion is finally discussed, connecting dissolution rate, mass transfer of metal ions in a metal oxide film and film growth. (author)

  3. Exploratory shaft liner corrosion estimate

    International Nuclear Information System (INIS)

    Duncan, D.R.

    1985-10-01

    An estimate of expected corrosion degradation during the 100-year design life of the Exploratory Shaft (ES) is presented. The basis for the estimate is a brief literature survey of corrosion data, in addition to data taken by the Basalt Waste Isolation Project. The scope of the study is expected corrosion environment of the ES, the corrosion modes of general corrosion, pitting and crevice corrosion, dissimilar metal corrosion, and environmentally assisted cracking. The expected internal and external environment of the shaft liner is described in detail and estimated effects of each corrosion mode are given. The maximum amount of general corrosion degradation was estimated to be 70 mils at the exterior and 48 mils at the interior, at the shaft bottom. Corrosion at welds or mechanical joints could be significant, dependent on design. After a final determination of corrosion allowance has been established by the project it will be added to the design criteria. 10 refs., 6 figs., 5 tabs

  4. Corrosion fatigue of steels

    International Nuclear Information System (INIS)

    Spaehn, H.; Wagner, G.H.

    1976-01-01

    Corrosion fatigue phenomena can be classified into two main groups according to the electrochemical state of the metal surface in the presence of electrolytes: the active and the passive state with an important sub-group of corrosion fatigue in the unstable passive state. The allowable stress for structures exposed to the conjoint action of corrosion and fatigue is influenced by many factors: kind of media, number of cycles, frequency, mean stress, size, notches, loading mode, alloy composition and mechanical strength. A critical literature review shows contradictory results if a classification by the electrochemical surface state is not applied. Case histories and counter measures illustrate the practical importance of corrosion fatigue in many branches of industry as well as the urgent need for a better knowledge about the mutual influence of the phenomena to get rules by which the engineer can appraise the risk of corrosion fatigue. (orig.) [de

  5. Long-time water level observations at the HDR-testsite Soultz-sous-Forets

    Energy Technology Data Exchange (ETDEWEB)

    Dornstaedter, J; Heinemann-Glutsch, B; Zaske, J [GTC-Kappelmeyer GmbH, Karlsruhe (Germany)

    1997-12-01

    Pressure or water level measurements have been performed by GTC in different wells at the geothermal testsite Soultz-sous-Forets for six years now. The water lever variations are mainly influenced by earth tides, barometric pressure variations, hydraulic testing and stimulation. The small scale variations are influenced by tidal and barometric forcing functions, the large scale variations by hydraulic testing and stimulation. By analyzing such measurements it is possible to get important information about the hydrualic connections between the boreholes, as well as aquifer parameters. (orig./AKF)

  6. Leuconostoc rapi sp. nov., isolated from sous-vide cooked rutabaga

    DEFF Research Database (Denmark)

    Lyhs, Ulrike; Snauwaert, I.; Pihlajaviita, S.

    2015-01-01

    A Gram-positive, ovoid lactic acid bacterium, strain LMG 27676T, was isolated from a spoiled sous-vide cooked rutabaga. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the genus Leuconostoc, with Leuconostoc kimchi and Leuconostoc miyukkimchii as nearest neighbours (99.......1 and 98.8% 16S rRNA gene sequence similarity towards the type strain, respectively). Phylogenetic analysis of the 16S rRNA gene, multilocus sequence analysis of the pheS, rpoA and atpA genes, and biochemical and genotypic characteristics allowed to differentiate strain LMG 27676T from all established...

  7. Changes provoked by boiling, steaming and sous-vide cooking in the lipid and volatile profile of European sea bass.

    Science.gov (United States)

    Nieva-Echevarría, Bárbara; Manzanos, María J; Goicoechea, Encarnación; Guillén, María D

    2017-09-01

    This study aims to shed light on the changes provoked by boiling, steaming and sous-vide cooking on the lipids and volatile profile of farmed and wild European sea bass meat. None of the cooking techniques provoked changes due to hydrolytic or oxidation processes detectable by 1 H NMR on sea bass lipids. The lipid profile of main and minor lipidic components was maintained after cooking. However, study by SPME-GC/MS evidenced that steaming and sous-vide cooking modified the volatile profile of sea bass meat, especially in farmed specimens. The compounds generated came from the occurrence, to a very small extent, of lipid and protein degradation. By contrast, boiling scarcely modified the initial characteristics of raw sea bass. Thus, from a sensory point of view and considering the odour-active compounds generated, steaming and sous-vide cooking provoked more noticeable changes than boiling, especially in farmed sea bass meat. Copyright © 2017. Published by Elsevier Ltd.

  8. Automated Methods Of Corrosion Measurements

    DEFF Research Database (Denmark)

    Bech-Nielsen, Gregers; Andersen, Jens Enevold Thaulov; Reeve, John Ch

    1997-01-01

    The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell.......The chapter describes the following automated measurements: Corrosion Measurements by Titration, Imaging Corrosion by Scanning Probe Microscopy, Critical Pitting Temperature and Application of the Electrochemical Hydrogen Permeation Cell....

  9. Les effets potentiels du taping chez une population adulte souffrant d'un conflit sous-acromial

    OpenAIRE

    Roch, Sylvie; Thétaz, Alain; Balthazard, Pierre

    2012-01-01

    Introduction : Le conflit sous-acromial est une pathologie fréquente qui touche une grande partie de la population. Quelques revues de la littérature recommandent une prise en charge spécifique, mais peu d’études proposent le taping comme adjuvant aux traitements préconisés. Ainsi ce travail de bachelor a pour objectif de déterminer les effets potentiels du taping chez une population adulte souffrant de conflit sous-acromial. Méthodologie : Notre recherche d’études s’est effectuée de janvier ...

  10. Vacuum brazing of metals (1961); Brassure sous vide des metaux (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Lapujoulade, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    We have studied brazing in vacuum aiming its application for the making of containers and apparatus meant for high vacuum (p < 10{sup -8} torr). We first define the wettability of a brazing alloy on a metal and we remind the influence of the various parameters which act on this wettability (nature of the solid, of the liquid, geometrical and physicochemical state of the surface, metallurgical reactions occurring at the interface, temperature, time). We give then the results of the tests carried out in order to determine the conditions of wettability in vacuum of some brazing alloys on metals which can be used for the above mentioned apparatus (stainless steel, aluminium, bronze, titanium, zirconium, kovar, nickel, copper). (author) [French] Nous avons etudie la brasure sous vide en vue de son application a la construction d'enceintes et apparelilage destines a l'obtention des vides eleves (p < 10{sup -8} torr). Nous definissons d'abord la mouillabilite d'une brasure sur un metal et nous rappelons l'influence des differents parametres qui agissent sur cette mouillabilite (nature du solide, du liquide, etat geometrique et physico-chimique de la surface, reactions metallurgiques a l'interface, temperature, temps). Nous donnons ensuite les resultats des essais effectues dans le but de determiner les conditions de mouillabilite sous vide de certaines brassures sur des metaux utilisables dans les constructions mentionnees ci-dessus (acier inoxydable, bronze d'aluminium, titane, zirconium, kovar, nickel, cuivre). (auteur)

  11. Corrosion in power industry

    International Nuclear Information System (INIS)

    Ventakeshwarlu, K.S.

    1979-01-01

    A brief account of the problem areas encountered as a result of corrosion in the electrical power industry including nuclear power industry is given and some of the measures contemplated and/or implemented to control corrosion are outlined. The corrosion problems in the steam generators and cladding tubes of the nuclear power plant have an added dimension of radioactivation which leads to contamination and radiation field. Importance of monitoring water quality and controlling water chemistry by addition of chemicals is emphasised. (M.G.B.)

  12. Corrosion of reactor materials

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1963-01-15

    Much operational experience and many experimental results have accumulated in recent years regarding corrosion of reactor materials, particularly since the 1958 Geneva Conference on the Peaceful Uses of Atomic Energy, where these problems were also discussed. It was, felt that a survey and critical appraisal of the results obtained during this period had become necessary and, in response to this need, IAEA organized a Conference on the Corrosion of Reactor Materials at Salzburg, Austria (4-9 June 1962). It covered many of the theoretical, experimental and engineering problems relating to the corrosion phenomena which occur in nuclear reactors as well as in the adjacent circuits

  13. Modelling reinforcement corrosion in concrete

    DEFF Research Database (Denmark)

    Michel, Alexander; Geiker, Mette Rica; Stang, Henrik

    2012-01-01

    A physio-chemical model for the simulation of reinforcement corrosion in concrete struc-tures was developed. The model allows for simulation of initiation and subsequent propaga-tion of reinforcement corrosion. Corrosion is assumed to be initiated once a defined critical chloride threshold......, a numerical example is pre-sented, that illustrates the formation of corrosion cells as well as propagation of corrosion in a reinforced concrete structure....

  14. Corrosion of PWR steam generators

    International Nuclear Information System (INIS)

    Garnsey, R.

    1979-01-01

    Some designs of pressurized water reactor (PWR) steam generators have experienced a variety of corrosion problems which include stress corrosion cracking, tube thinning, pitting, fatigue, erosion-corrosion and support plate corrosion resulting in 'denting'. Large international research programmes have been mounted to investigate the phenomena. The operational experience is reviewed and mechanisms which have been proposed to explain the corrosion damage are presented. The implications for design development and for boiler and feedwater control are discussed. (author)

  15. Corrosion of valve metals

    International Nuclear Information System (INIS)

    Draley, J.E.

    1976-01-01

    A general survey related to the corrosion of valve metals or film-forming metals. The way these metals corrode with some general examples is described. Valve metals form relatively perfect oxide films with little breakdown or leakage when anodized

  16. Corrosion in Electronics

    DEFF Research Database (Denmark)

    Ambat, Rajan; Gudla, Helene Virginie Conseil; Verdingovas, Vadimas

    2017-01-01

    Electronic control units, power modules, and consumer electronics are used today in a wide variety of varying climatic conditions. Varying external climatic conditions of temperature and humidity can cause an uncontrolled local climate inside the device enclosure. Uncontrolled humidity together...... and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in the presence of water film formed due to humidity exposure and bias conditions on the PCBA surface. This article provides a short review of the corrosion reliability issues of electronics due...... to the use of electronics under varying humidity conditions. Important PCBA aspects, which are fundamental to the corrosion cell formation under humid conditions, are discussed. Effect of hygroscopic residues from the process and service and their role in assisting water film build up and corrosion...

  17. Microbiologically Influenced Corrosion

    Science.gov (United States)

    2009-01-01

    species grow as multicel- lular filaments called hyphae forming a mycelium, some fungal species also grow as single cells. Sexual and asexual...reinforced fluorinated 18 MICROBIOLOGICALLY INFLUENCED CORROSION polyimide composites due to hyphae penetration into resin interiors. The

  18. Carbon Dioxide Corrosion:

    DEFF Research Database (Denmark)

    Fosbøl, Philip Loldrup

    2008-01-01

    CO2 corrosion is a general problem in the industry and it is expensive. The focus of this study is an oil gas production related problem. CO2 corrosion is observed in offshore natural gas transportation pipelines. A general overview of the problem is presented in chapter 1. The chemical system...... with the basic thermodynamics of electrolytes in chapter 2, the extension and general description of electrolyte mass transport in chapter 3, and the electrochemical kinetics of corrosion in chapter 4. A literature overview of CO2 corrosion is shown in chapter 5 and possible extensions of the models...... and validated against heat capacity data. The model is also fitted to experimental data produced and shown in chapter 8 for SLE in the Na2CO3-NaHCO3-MEG-H2O system. The application of the above model is shown in chapter 9. Here the thermodynamic correction factors are calculated. These show how the diffusion...

  19. BWR steel containment corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Tan, C.P.; Bagchi, G.

    1996-04-01

    The report describes regulatory actions taken after corrosion was discovered in the drywell at the Oyster Creek Plant and in the torus at the Nine Mile Point 1 Plant. The report describes the causes of corrosion, requirements for monitoring corrosion, and measures to mitigate the corrosive environment for the two plants. The report describes the issuances of generic letters and information notices either to collect information to determine whether the problem is generic or to alert the licensees of similar plants about the existence of such a problem. Implementation of measures to enhance the containment performance under severe accident conditions is discussed. A study by Brookhaven National Laboratory (BNL) of the performance of a degraded containment under severe accident conditions is summarized. The details of the BNL study are in the appendix to the report.

  20. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  1. Thermal and radiation induced polymerisation of carbon sub-oxide; Polymerisation thermique et sous rayonnement du sous-oxyde de carbone

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Michel

    1964-03-15

    This research thesis addresses the study of the polymerisation of carbon sub-oxide (C{sub 3}O{sub 2}) in gaseous phase. As this work is related to other researches dealing with the reactions of the graphite-CO{sub 2} system which occur in graphite-moderated nuclear reactors, a first intention was to study the behaviour of C{sub 3}O{sub 2} when submitted to radiations. Preliminary tests showed that the most remarkable result of this action was the formation of a polymer. It was also noticed that the polymerisation of this gas was spontaneous however slower at room temperature. The research thus focused on this polymerisation, and on the formula of the obtained polymer. After some generalities, the author reports the preparation, purification and storage and conservation of the carbon sub-oxide. The next parts report the kinetic study of thermal polymerisation, the study of polymerisation under γ rays, the study of the obtained polymer by using visible, UV and infrared spectroscopy, electronic paramagnetic resonance, and semi-conductivity measurements [French] Le but de ce travail est l'etude de la polymerisation du sous-oxyde de carbone, C{sub 3}O{sub 2}, en phase gazeuse. Ce travail est en relation avec d'autres recherches concernant les reactions du systeme graphite-CO{sub 2} qui se produisent dans les reacteurs nucleaires de la filiere moderee au graphite. Notre premiere intention etait donc d'etudier le comportement de C{sub 3}O{sub 2} sous l'action des rayonnements. Or des essais preliminaires nous ont rapidement montre que le resultat le plus marquant de cette action etait l'obtention d'un polymere. On a egalement remarque que ce gaz polymerisait spontanement - quoique moins rapidement - a la temperature ambiante. Notre etude s'est donc circonscrite a cette polymerisation, avec ou sans rayonnements, ainsi qu'a son aboutissement: le polymere, dont nous avons tente d'eclaircir la formule. Au terme de cette etude, bien que certains points ne soient pas encore

  2. Corrosion of beryllium

    International Nuclear Information System (INIS)

    Mueller, J.J.; Adolphson, D.R.

    1987-01-01

    The corrosion behavior of beryllium in aqueous and elevated-temperature oxidizing environments has been extensively studied for early-intended use of beryllium in nuclear reactors and in jet and rocket propulsion systems. Since that time, beryllium has been used as a structural material in les corrosive environments. Its primary applications include gyro systems, mirror and reentry vehicle structures, and aircraft brakes. Only a small amount of information has been published that is directly related to the evaluation of beryllium for service in the less severe or normal atmospheric environments associated with these applications. Despite the lack of published data on the corrosion of beryllium in atmospheric environments, much can be deduced about its corrosion behavior from studies of aqueous corrosion and the experiences of fabricators and users in applying, handling, processing, storing, and shipping beryllium components. The methods of corrosion protection implemented to resist water and high-temperature gaseous environments provide useful information on methods that can be applied to protect beryllium for service in future long-term structural applications

  3. Monitoring corrosion rates and localised corrosion in low conductivity water

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2006-01-01

    Monitoring of low corrosion rates and localised corrosion in a media with low conductivity is a challenge. In municipal district heating, quality control may be improved by implementing on-line corrosion monitoring if a suitable technique can be identified to measure both uniform and localised...... corrosion. Electrochemical techniques (LPR, EIS, crevice corrosion current) as well as direct measurement techniques (high-sensitive electrical resistance, weight loss) have been applied in operating plants. Changes in the corrosion processes are best monitored in non-aggressive, low conductivity media...

  4. Effect of sous vide processing on physicochemical, ultrastructural, microbial and sensory changes in vacuum packaged chicken sausages.

    Science.gov (United States)

    Naveena, B M; Khansole, Panjab S; Shashi Kumar, M; Krishnaiah, N; Kulkarni, Vinayak V; Deepak, S J

    2017-01-01

    The processing of sous vide chicken sausages was optimized under vacuum packaging condition and cooking at 100 ℃ for 30 min (SV30), 60 min (SV60) and 120 min (SV120) and compared with aerobically cooked control at 100 ℃ for 30 min. Sous vide processing of chicken sausages (SV30) produced higher (p emulsion ultra-structure due to SV30 processing relative to control sausages. Sous vide processing of chicken sausages enriched with rosemary diterpene phenols retained the freshness and quality up to 120 days during storage at 4 ± 1 ℃ relative to control sausages that were spoiled on 20th day. Lipid oxidation and microbial growth remained below the spoilage levels for all the SV-processed sausages throughout the storage and addition of rosemary diterpene mixture at 0.02% v/w reduced the microbial growth and improved (p < 0.05) the sensory attributes. Our results demonstrate that sous vide processing minimizes lipid oxidation and microbial growth of chicken sausages with improved product quality and shelf-life at 4 ± 1 ℃. © The Author(s) 2016.

  5. Hot pressing of U-UC cermets and stoichiometric uranium monocarbide; Preparation par frittage sous charge de cermets U-UC et de monocarbure stoechiometrique

    Energy Technology Data Exchange (ETDEWEB)

    Dubuisson, J; Houyvet, A; Le Boulbin, E; Lucas, R; Moranville, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    High density fuels, either in uranium monocarbide or in U-UC cermets have been prepared on laboratory-scale, by hot pressing of mixtures of uranium powder and graphite in suitable proportions. Uranium powder is prepared by calcium reduction of UO{sub 2} followed by an acetic leaching at low temperature. An adequate protection-treatment permits the manipulation of the powder in the open air. Uranium and Graphite powders are intimately mixed and then hot pressed in a double effect graphite die at a temperature of 900-1000 deg. C under a charge of 200 kg/cm{sup 2} during 3 hours. A special design of the die avoids the breaking of the graphite during the sintering. In this way, samples are prepared, the characteristics of which are: 1) {+-} 5 pour cent of homogeneity for a ratio height/diameter = 2. 2) almost theoretical density (98 pour cent) 3) low concentration of unreacted carbon (heat treatment of stoichiometric monocarbide can be useful for completion of reaction) 4) the micrographic examination shows: - a network of monocarbide surrounding uranium in the case of low concentration cermets (<2,5 per cent C) - two networks intimately mixed for high concentration cermets (<2,5 per cent C) - a fine grain structure for the monocarbide (10 u). 5) In every case, the X rays examinations show a fine grain structure without any orientation, and no UC{sub 2}. Some indications are given on the physical (thermal cycling, conductibility) and chemical properties (corrosion, reaction with cladding materials). (author)Fren. [French] Une methode de preparation de combustibles de haute densite, soit en monocarbure d'uranium, soit en cermets U-UC, a ete mise au point au laboratoire. Il s'agit du frittage sous charge de melanges de poudres d'uranium et de graphite en proportion convenable. La poudre d'uranium est elaboree par calciothermie de l'oxyde UO{sub 2} suivie d'un lavage acetique a basse temperature. Un traitement de protection adequat pe sa manipulation a l'air. Les poudres

  6. Corrosion and anticorrosion. Industrial practice

    International Nuclear Information System (INIS)

    Beranger, G.; Mazille, H.

    2002-01-01

    This book comprises 14 chapters written with the collaboration of about 50 French experts of corrosion. It is complementary to another volume entitled 'corrosion of metals and alloys' and published by the same editor. This volume comprises two parts: part 1 presents the basic notions of corrosion phenomena, the properties of surfaces, the electrochemical properties of corrosion etc.. Part 2 describes the most frequent forms of corrosion encountered in industrial environments and corresponding to specific problems of protection: marine environment, atmospheric corrosion, galvanic corrosion, tribo-corrosion, stress corrosion etc.. The first 8 chapters (part 1) treat of the corrosion problems encountered in different industries and processes: oil and gas production, chemical industry, phosphoric acid industry, PWR-type power plants, corrosion of automobile vehicles, civil engineering and buildings, corrosion of biomaterials, non-destructive testing for the monitoring of corrosion. The other chapters (part 2) deal with anticorrosion and protective coatings and means: choice of materials, coatings and surface treatments, thick organic coatings and enamels, paints, corrosion inhibitors and cathodic protection. (J.S.)

  7. Guide pour la rédaction de cahiers des charges pour la sous-traitance en mécano-soudage

    CERN Document Server

    Cheminat, Olivier

    2016-01-01

    Ce rapport est principalement dédié aux rédacteurs de cahiers des charges lors de sous-traitance en soudage. Le choix de faire sous-traiter une fabrication et le choix du sous-traitant revêtent une triple dimension technique, économique et stratégique. Un sous-traitant n'est pas un simple fournisseur ; il est un véritable partenaire technique pour le donneur d'ordre qui lui confie la réalisation d'un produit qu'il a lui-même conçu. La sous-traitance nécessite alors, outre un audit préalable du partenaire, un suivi en continu, à distance, et une communication entre le donneur d'ordre et le sous-traitant. Le cahier des charges est un des éléments de cette communication. C'est un outil essentiel, notamment lorsque le marché est soumis à des normes, imposées par contrat entre le donneur d'ordre et le sous-traitant. Ce présent document est un guide pour la rédaction du document de consultation, afin d'être le plus précis et exhaustif possible, mais il ne saurait être utilisé pour établi...

  8. Registration of vehicles at the Gex sous-préfecture: now by appointment only

    CERN Multimedia

    2016-01-01

    The Gex sous-préfecture has informed CERN that it has taken the following steps in order to reduce waiting times at its counters for the issue of carte grise vehicle registration certificates. As of 1 February 2016, you must book an appointment via the website http://www.rdv.ain.gouv.fr/ for all services relating to the registration of vehicles, in particular the:   change of the holder of a registration certificate, issue of a certificat de situation administrative (administrative status certificate required for the sale of a vehicle), change of marital status (or company name in the case of legal entities), change of address, change in the technical specification of the vehicle, corrections to registration certificates, equests for duplicates (loss or theft of registration certificates), registration of a diplomatic vehicle (CERN), registration of a new vehicle, registration of vehicles purchased tax-free in the Pays de Gex free zone (formerly TTW series), and import of vehicles (from ...

  9. Patrimonialiser les bases de sous-marins et le Mur de l’Atlantique

    OpenAIRE

    Prelorenzo, Claude

    2014-01-01

    Le Mur de l’Atlantique court de la frontière espagnole jusqu’au nord de la Norvège. Au sein de ce dispositif sont installées cinq bases de sous-marins : Dunkerque, Saint-Nazaire, Lorient, La Rochelle et Bordeaux. Après une période de purgatoire, liée aux souvenirs trop frais des bombardements qu’ils ont attirés sur les villes, les édifices du mur sont entrés dans la sphère de la culture et du tourisme. Nous posons alors la question suivante : de quoi ces édifices portent-ils témoignage, et no...

  10. Raconter l’Histoire (sous la direction de Prstojevic A.

    Directory of Open Access Journals (Sweden)

    Sophie Thiriar

    2011-10-01

    Full Text Available Sous le titre Raconter l’Histoire, Alexandre Prstojevic a réuni treize articles, faisant suite à deux colloques qui ont eu lieu à Paris en mai 2006 et à Montréal en octobre de la même année. Treize pointures du monde slave se sont intéressées pour l’occasion à la représentation littéraire et cinématographique de l’histoire – principalement celle de l’Europe centrale et orientale – après le spectacle mortifère des deux guerres mondiales. Suite aux multiples expériences déshumanisantes dont est...

  11. Scintigraphy of the Pericerebral Subarachnoidspaces; Scintigraphie des Espaces Sous-Arachnoidiens Pericerebraux

    Energy Technology Data Exchange (ETDEWEB)

    Oberson, R.; Martini, T. [Institut Universitaire de Radiologie Medicale, Hopital Cantonal, Lausanne (Switzerland)

    1969-05-15

    -auricular shunt of the C.S.F. in cases of symptomatic hydrocephalus of traumatic or occult origin in adult or child patients. The study was based on an analysis of over 100 scintigrams of the pericerebral subarachnoid cavities. From this, the authors were gradually able to work out the normal and pathological symptomatology of this field, from the point of view of both cisternal morphology and fluid hydrodynamics. (author) [French] L'exploration des espaces sous-arachnoiediens pericerebraux par les radioisotopes (cisternographie radioisotopique ou 'RISA- cisternography' ) prend une place de plus en plus importante parmi les techniques neuroradioisotopiques de diagnostic. Elle fournit de precieux renseignements sur la permeabilite des espaces sous-arachnoiediens et sur la dynamique du liquide cephalo-rachidien (LCR). On doit actuellement la considerer comme indispensable et irremplacable dans le diagnostic de certaines affections neurologiques, tout comme la gamma-encephalographie et les techniques neuroradiologiques plus classiques (angiographie et pneumographie cerebrales). En effet, cet examen est seul a preciser l'aspect morphologique global des espaces sous-arachnoiediens pericerebraux; tout en renseignant sur la permeabilite des citernes pericerebrales et des sillons de la convexite, il fournit une image scintigraphique typique et symetrique, facile a observer, de face et de profil, des voies principales de circulation du LCR cisternal. L'image scintigraphique d'une citerne indique qu'elle est permeable et que l'espace sous-jacent l'est aussi. Du point de vue dynamique, la cisternographie radioisotopique, outre la demonstration par voie scintigraphique de la permeabilite des citernes, met en evidence le schema normal ou pathologique de la dynamique du LCR. Le schema normal de progression du LCR est actuellement bien etabli. Il est du plus haut interet de le connaitre afin de distinguer deja quelques syndromes pathologiques: la presence d'une fistule de LCR (la

  12. Evaluation of corrosive behavior of SAE 5155 by corrosion environment

    International Nuclear Information System (INIS)

    An, Jae Pil; Park, Keyung Dong

    2005-01-01

    In this study, the influence of shot peening and corrosive condition for corrosion property was investigated on immersed in 3.5% NaCl, 10% HNO 3 + 3% HF, 6% FeCl 3 . The immersion test was performed on two kinds of specimen. The immersion periods was performed 30days. Corrosion potential, weight loss were investigated from experimental results. From test results, the effect of shot peening on the corrosion was evaluated

  13. Microbiologically induced corrosion

    International Nuclear Information System (INIS)

    Stein, A.A.

    1988-01-01

    Biological attack is a problem that can affect all metallic materials in a variety of environments and systems. In the power industry, corrosion studies have focused on condensers and service water systems where slime, barnacles, clams, and other macro-organisms are easily detected. Efforts have been made to eliminate the effect of these organisms through the use of chlorination, backflushing, organic coating, or thermal shock. The objective is to maintain component performance by eliminating biofouling and reducing metallic corrosion. Recently, corrosion of power plant components by micro-organisms (bacteria) has been identified even in very clean systems. A system's first exposure to microbiologically induced corrosion (MIC) occurs during its first exposure to an aqueous environment, such as during hydrotest or wet layup. Corrosion of buried pipelines by sulfate-reducing bacteria has been studied by the petrochemical industry for years. This paper discusses various methods of diagnosing, monitoring, and controlling MIC in a variety of systems, as well as indicates areas where further study is needed

  14. Corrosion failure analysis as related to prevention of corrosion failures

    International Nuclear Information System (INIS)

    Suss, H.

    1977-10-01

    The factors and conditions which have contributed to many of the corrosion related service failures are discussed based on a review of actual case histories. The anti-corrosion devices which developed as a result of these failure analyses are reviewed, and the method which must be adopted and used to take advantage of the available corrosion prevention techniques is discussed

  15. Corrosion testing facilities in India

    International Nuclear Information System (INIS)

    Viswanathan, R.; Subramanian, Venu

    1981-01-01

    Major types of corrosion tests, establishment of specifications on corrosion testing and scope of their application in practice are briefly described. Important organizations in the world which publish specifications/standards are listed. Indian organizations which undertake corrosion testing and test facilities available at them are also listed. Finally in an appendix, a comprehensive list of specifications relevant to corrosion testing is given. It is arranged under the headings: environmental testing, humidity tests, salt spray/fog tests, immersion tests, specification corrosion phenomena, (tests) with respect to special corrosion media, (tests) with respect to specific corrosion prevention methods, and specific corrosion tests using electrical and electrochemical methods (principles). Each entry in the list furnishes information about: nature of the test, standard number, and its specific application. (M.G.B.)

  16. Acid corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Chen, N G

    1964-04-28

    An acid corrosion inhibitor is prepared by a 2-stage vacuum evaporation of effluents obtained from the ammonia columns of the coking oven plant. The effluent, leaving a scrubber in which the phenols are removed at a temperature of 98$C, passes through a quartz filter and flows into a heated chamber in which it is used for preheating a solution circulating through a vacuum unit, maintaining the temperature of the solution at 55$ to 60$C. The effluent enters a large tank in which it is boiled at 55$ to 60$C under 635 to 640 mm Hg pressure. Double evaporation of this solution yields a very effective acid corrosion inhibitor. Its corrosion-preventing effect is 97.9% compared with 90.1% for thiourea and 88.5% for urotropin under identical conditions.

  17. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  18. Corrosion Monitoring System

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Russ Braunling

    2004-10-31

    The Corrosion Monitoring System (CMS) program developed and demonstrated a continuously on-line system that provides real-time corrosion information. The program focused on detecting pitting corrosion in its early stages. A new invention called the Intelligent Ultrasonic Probe (IUP) was patented on the program. The IUP uses ultrasonic guided waves to detect small defects and a Synthetic Aperture Focusing Technique (SAFT) algorithm to provide an image of the pits. Testing of the CMS demonstrated the capability to detect pits with dimensionality in the sub-millimeter range. The CMS was tested in both the laboratory and in a pulp and paper industrial plant. The system is capable of monitoring the plant from a remote location using the internet.

  19. Stochastic theory of fatigue corrosion

    Science.gov (United States)

    Hu, Haiyun

    1999-10-01

    A stochastic theory of corrosion has been constructed. The stochastic equations are described giving the transportation corrosion rate and fluctuation corrosion coefficient. In addition the pit diameter distribution function, the average pit diameter and the most probable pit diameter including other related empirical formula have been derived. In order to clarify the effect of stress range on the initiation and growth behaviour of pitting corrosion, round smooth specimen were tested under cyclic loading in 3.5% NaCl solution.

  20. Corrosion-resistant metal surfaces

    Science.gov (United States)

    Sugama, Toshifumi [Wading River, NY

    2009-03-24

    The present invention relates to metal surfaces having thereon an ultrathin (e.g., less than ten nanometer thickness) corrosion-resistant film, thereby rendering the metal surfaces corrosion-resistant. The corrosion-resistant film includes an at least partially crosslinked amido-functionalized silanol component in combination with rare-earth metal oxide nanoparticles. The invention also relates to methods for producing such corrosion-resistant films.

  1. Rhenium corrosion in chloride melts

    International Nuclear Information System (INIS)

    Stepanov, A.D.; Shkol'nikov, S.N.; Vetyukov, M.M.

    1989-01-01

    The results investigating rhenium corrosion in chloride melts containing sodium, potassium and chromium ions by a gravimetry potentials in argon atmosphere in a sealing quarth cell are described. Rhenium corrosion is shown to be rather considerable in melts containing CrCl 2 . The value of corrosion rate depending on temperature is determined

  2. Accelerated cyclic corrosion tests

    Directory of Open Access Journals (Sweden)

    Prošek T.

    2016-06-01

    Full Text Available Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

  3. Achievments of corrosion science and corrosion protection technology

    International Nuclear Information System (INIS)

    Fontana, M.; Stehjl, R.

    1985-01-01

    Problems of corrosion-mechanical strength of metals, effect of corrosive media on creep characteristics are presented. New concepts of the mechanism of corrosion cracking and its relation to hydrogen embrittlement are described. Kinetics and mechanism of hydrogen embrittlement effect on the process of corrosion cracking of different steels and alloys are considered. The dependence of such types of failure on various structural factors is shown. Data on corrosion cracking of high-strength aluminium and titanium alloys, mechanism of the processes and protective methods are given

  4. Mesures de contraintes in-situ. Méthode de relaxation des carottes Measuring in-Situ Stresses. Relaxation Method with Core Samples

    Directory of Open Access Journals (Sweden)

    Perreau P.

    2006-11-01

    Full Text Available Dans cet article, on se propose de présenter les premiers résultats de l'étude de la méthode d'évaluation des contraintes par mesure de déformations différées d'une carotte après son extraction. Le travail correspondant a été réalisé dans le cadre du projet ARTEP Fracturation hydraulique . Les principes de cette méthode et les quelques éléments d'interprétation récemment publiés dans la littérature sont exposés dans un premier temps. Les résultats de deux campagnes de mesures sur deux puits de la SNEA-P (Soudron, novembre 1985 et Lanot, juillet 1986 sont ensuite présentés. Ces essais ont mis en évidence que les déformations différées d'une carotte dues au relachement des contraintes sont effectivement mesurables. Cependant, une interprétation quantitative de ces mesures nécessite une amélioration des conditions expérimentales (stabilisation thermique, stabilisation de l'état de saturation. This article describes the first results of research on a method of evaluating stresses by measuring the differred deformations of a core sample after it has been extracted. The corresponding research was done within the framework of an ARTEP project on Hydraulic Fracturing . The principles of this method and several interpretation aspects published recently in the literature are described in the first part. Then the results of two measurement campaigns using two SNEA-P wells (Soudron in November 1985 and Lanot in July 1986 are described. These tests revealed that the differed deformations of a core sample due to the relaxing of stresses can effectively be measured. However, a quantitative interpretation of these measurements requires an improvement to be made in the experimental conditions (thermal stabilization, stabilization of the state of saturation.

  5. Corrosion resistant cemented carbide

    International Nuclear Information System (INIS)

    Hong, J.

    1990-01-01

    This paper describes a corrosion resistant cemented carbide composite. It comprises: a granular tungsten carbide phase, a semi-continuous solid solution carbide phase extending closely adjacent at least a portion of the grains of tungsten carbide for enhancing corrosion resistance, and a substantially continuous metal binder phase. The cemented carbide composite consisting essentially of an effective amount of an anti-corrosion additive, from about 4 to about 16 percent by weight metal binder phase, and with the remaining portion being from about 84 to about 96 percent by weight metal carbide wherein the metal carbide consists essentially of from about 4 to about 30 percent by weight of a transition metal carbide or mixtures thereof selected from Group IVB and of the Periodic Table of Elements and from about 70 to about 96 percent tungsten carbide. The metal binder phase consists essentially of nickel and from about 10 to about 25 percent by weight chromium, the effective amount of an anti-corrosion additive being selected from the group consisting essentially of copper, silver, tine and combinations thereof

  6. Corrosion resistant steel

    International Nuclear Information System (INIS)

    Zubchenko, A.S.; Borisov, V.P.; Latyshev, V.B.

    1980-01-01

    Corrosion resistant steel for production of sheets and tubes containing C, Mn, Cr, Si, Fe is suggested. It is alloyed with vanadium and cerium for improving tensile properties and ductility. The steel can be melted by a conventional method in electric-arc or induction furnaces. The mentioned steel is intended to be used as a substitute for nickel-bearing austenitic steels

  7. Corrosion in seawater systems

    International Nuclear Information System (INIS)

    Henrikson, S.

    1988-01-01

    Highly alloyed stainless steels have been exposed to natural chlorinated and chlorine-free seawater at 35 deg. C. Simulated tube-tubesheet joints, weld joints and galvanic couples with titanium, 90/10 CuNi and NiAl bronze were tested and evaluated for corrosion. The corrosion rates of various anode materials - zinc, aluminium and soft iron - were also determined. Finally the risk of hydrogen embrittlement of tubes of ferritic stainless steels and titanium as a consequence of cathodic protection was studied. An attempt was also made to explain the cracking mechanism of the ferritic steels by means of transmission electron microscopy. One important conclusion of the project is that chlorinated seawater is considerably more corrosive to stainless steels than chlorine-free water, whereas chlorination reduces the rate of galvanic corrosion of copper materials coupled to stainless steels. Hydrogen embrittlement of ferritic stainless steels and titanium as a consequence of cathodic protection of carbon steel or cast iron in the same structure can be avoided by strict potentiostatic control of the applied potential. (author)

  8. Corrosion resistant composite materials

    International Nuclear Information System (INIS)

    Ul'yanin, E.A.

    1986-01-01

    Foundations for corrosion-resistant composite materials design are considered with account of components compatibility. Fibrous and lamellar composites with metal matrix, dispersion-hardened steels and alloys, refractory metal carbides-, borides-, nitrides-, silicides-based composites are described. Cermet compositions and fields of their application, such as protective coatings for operation in agressive media at high temperatures, are presented

  9. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  10. Les particules illocutoires, variable d’ajustement de la traduction sous-titrante au cinéma

    Directory of Open Access Journals (Sweden)

    Ève Vayssière

    2010-12-01

    Full Text Available Die illokutiven Partikel fungieren als Anpassungsvariable, die beim Übersetzungsakt zur Untertitelung von Filmen entweder weggelassen werden oder erscheinen. Wenn sie einfach gelöscht werden, ergeben sich weder grammatikalische Störungen noch Informationsverlust. Das Auftauchen dieser Partikel in den deutschen Untertiteln zeigt jedoch, wie wichtig sie sind: Als Partikel der Oralität tragen sie zur Idiomatizität bei.Les particules illocutoires sont des variables d’ajustement lors de l’acte de traduction sous-titrante au cinéma, elles peuvent être supprimées sans que cela occasionne de dysfonctionnement grammatical et elles disparaissent lors de la traduction en français sans que cela occasionne une perte d’informations. Leur apparition dans les sous-titres allemands montre néanmoins leur importance : particules de l’oralité, elles sont vecteur d’« idiomaticité ».

  11. Corrosion potential analysis system

    Science.gov (United States)

    Kiefer, Karl F.

    1998-03-01

    Many cities in the northeastern U.S. transport electrical power from place to place via underground cables, which utilize voltages from 68 kv to 348 kv. These cables are placed in seamless steel pipe to protect the conductors. These buried pipe-type-cables (PTCs) are carefully designed and constantly pressurized with transformer oil to prevent any possible contamination. A protective coating placed on the outside diameter of the pipe during manufacture protects the steel pipe from the soil environment. Notwithstanding the protection mechanisms available, the pipes remain vulnerable to electrochemical corrosion processes. If undetected, corrosion can cause the pipes to leak transformer oil into the environment. These leaks can assume serious proportions due to the constant pressure on the inside of the pipe. A need exists for a detection system that can dynamically monitor the corrosive potential on the length of the pipe and dynamically adjust cathodic protection to counter local and global changes in the cathodic environment surrounding the pipes. The northeastern United States contains approximately 1000 miles of this pipe. This milage is critical to the transportation and distribution of power. So critical, that each of the pipe runs has a redundant double running parallel to it. Invocon, Inc. proposed and tested a technically unique and cost effective solution to detect critical corrosion potential and to communicate that information to a central data collection and analysis location. Invocon's solution utilizes the steel of the casing pipe as a communication medium. Each data gathering station on the pipe can act as a relay for information gathered elsewhere on the pipe. These stations must have 'smart' network configuration algorithms that constantly test various communication paths and determine the best and most power efficient route through which information should flow. Each network station also performs data acquisition and analysis tasks that ultimately

  12. Patrimonialiser les bases de sous-marins et le Mur de l’Atlantique

    Directory of Open Access Journals (Sweden)

    Claude Prelorenzo

    2011-06-01

    Full Text Available Le Mur de l’Atlantique court de la frontière espagnole jusqu’au nord de la Norvège. Au sein de ce dispositif sont installées cinq bases de sous-marins : Dunkerque, Saint-Nazaire, Lorient, La Rochelle et Bordeaux. Après une période de purgatoire, liée aux souvenirs trop frais des bombardements qu’ils ont attirés sur les villes, les édifices du mur sont entrés dans la sphère de la culture et du tourisme. Nous posons alors la question suivante : de quoi ces édifices portent-ils témoignage, et nous envisageons plusieurs aspects : leur évident modernisme qui les situe à un moment de l’histoire de l’architecture, leur hétérogénéité qui fait de ces bâtiments des sortes d’ovni, sans aucun rapport ni d’échelle ni de forme avec l’architecture civile, une technique d’enfouissement et de camouflage génératrice d’un nouveau paysage. Mais ces édifices peuvent-ils être exonérés de leur but guerrier ? Quel est le message de leur recyclage dans le culturel, le festif ou le commercial ? Deux bases de sous-marins sont plus particulièrement présentées, celle de Saint-Nazaire et celle de Lorient.The Atlantic Wall stretches from the Spanish border to northern Norway. Within this system there are five bases for submarines: Dunkirk, Saint-Nazaire, Lorient, La Rochelle and Bordeaux. After a period of purgatory, with the painful memories of the wartime air raids which destroyed the cities around the bases, the buildings which the Atlantic Wall comprises have now entered the spheres of culture and tourism. What do these buildings bear witness to? Their frank modernism puts them at a precise moment in the history of architecture. Their heterogeneity makes them like UFOs, without any relation of scale or form to civil architecture. Their specific techniques of dissimulation and camouflage created new landscapes. But can these buildings be freed from the memories of their original military purpose? What message is

  13. Effects of combined electron-beam irradiation and sous-vide treatments on microbiological and other qualities of chicken breast meat

    International Nuclear Information System (INIS)

    Shamsuzzaman, K.; Lucht, L.; Chuaqui-Offermanns, N.

    1994-01-01

    The microbiological safety, refrigeration shelf-life, and nutritional quality of chicken breast meat were investigated following combined electron-beam irradiation and cooking under vacuum (sous-vide). Chicken breast meat inoculated with 10 6 CFU/g of Listeria monocytogenes was irradiated with an electron beam at doses up to 3.1 kGy under vacuum in barrier bags, cooked in a boiling water bath for 3 min 45 s (previously determined to achieve an internal temperature of 71.1 o C), and stored at 8 o C for up to 5 weeks. Listeria was undetectable in samples treated with combined sous-vide and irradiation at 3.1 kGy, but the organism survived the sous-vide treatment without irradiation and multiplied during storage. A similar study, conducted with uninoculated chicken breast meat, revealed that the product which received both irradiation (3 kGy) and sous-vide treatment had a shelf-life of at least 8 weeks at 8 o C, whereas the unirradiated samples treated sous-vide spoiled in 16 days. Listeria was undetectable in combination treated samples, but some of the unirradiated sous-vide samples tested after long storage showed high levels of Listeria. Some loss of thiamine occurred with the combined treatments. (author)

  14. Mobile evaporator corrosion test results

    International Nuclear Information System (INIS)

    Rozeveld, A.; Chamberlain, D.B.

    1997-05-01

    Laboratory corrosion tests were conducted on eight candidates to select a durable and cost-effective alloy for use in mobile evaporators to process radioactive waste solutions. Based on an extensive literature survey of corrosion data, three stainless steel alloys (304L, 316L, AL-6XN), four nickel-based alloys (825, 625, 690, G-30), and titanium were selected for testing. The corrosion tests included vapor phase, liquid junction (interface), liquid immersion, and crevice corrosion tests on plain and welded samples of candidate materials. Tests were conducted at 80 degrees C for 45 days in two different test solutions: a nitric acid solution. to simulate evaporator conditions during the processing of the cesium ion-exchange eluant and a highly alkaline sodium hydroxide solution to simulate the composition of Tank 241-AW-101 during evaporation. All of the alloys exhibited excellent corrosion resistance in the alkaline test solution. Corrosion rates were very low and localized corrosion was not observed. Results from the nitric acid tests showed that only 316L stainless steel did not meet our performance criteria. The 316L welded interface and crevice specimens had rates of 22.2 mpy and 21.8 mpy, respectively, which exceeds the maximum corrosion rate of 20 mpy. The other welded samples had about the same corrosion resistance as the plain samples. None of the welded samples showed preferential weld or heat-affected zone (HAZ) attack. Vapor corrosion was negligible for all alloys. All of the alloys except 316L exhibited either open-quotes satisfactoryclose quotes (2-20 mpy) or open-quotes excellentclose quotes (<2 mpy) corrosion resistance as defined by National Association of Corrosion Engineers. However, many of the alloys experienced intergranular corrosion in the nitric acid test solution, which could indicate a susceptibility to stress corrosion cracking (SCC) in this environment

  15. Production durable de légumes sous-utilisés en vue d'améliorer la ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Production durable de légumes sous-utilisés en vue d'améliorer la sécurité alimentaire en milieu ruralrity (Les légumes indigènes revêtent une importance capitale pour les femmes pauvres vivant en milieu rural, mais ont reçu, à ce jour, peu d'attention de la part des milieux de la recherche, du développement et des ...

  16. Integral modeling and financial impact of the geothermal situation and power plant at Soultz-sous-Forets

    International Nuclear Information System (INIS)

    Heidinger, Ph.

    2010-01-01

    The science about deep Enhanced Geothermal Systems (EGS) is still an emerging process and for further spreading economics is the key of the technology. To understand the financial situation, a program for economic evaluation was developed. This software (Euronaut) is completely modularized and considers all cash flows. Projects like an EGS are wrapped into tree-like structures. Based on the results which were gained at Soultz-sous-Forets, two configurations were designed. The first EGS configuration consists of a simplified two well (doublet) system where the dependencies of all components (mainly the reservoir, wells, pumps and the heat-to-power conversion unit) are physically and economically linked together. The realization of these dependencies and their complex interactions enable a sensitivity analysis of the borehole depth and reservoir depth, respectively. As a result, depth dependent effective costs and revenues of an EGS plant with the geohydrological characteristics of Soultz-sous-Forets are determined. As a future development, the second configuration will adapt the actual situation at Soultz-sous-Forets with the individual features of all four wells (GPK1 - GPK4). Then, this model can be used for all kinds of sensitivity analyses to clarify the impact of certain components or to optimize the operation scheme; e.g. the flow rates. (author)

  17. Improvement of microbiological safety of sous-vide meals by gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, J. E-mail: huto@omega.kee.hu; Polyak-Feher, K.; Andrassy, E.; Meszaros, L

    2002-03-01

    Experimental batches of smoked-cured pork in stewed beans sauce were inoculated with spores of psychrotrophic Bacillus cereus, more heat and radiation resistant than spores of non-proteolytic C. botulinum. After vacuum packaging, the meals were treated with combinations of pasteurizing heat treatments and gamma irradiation of 5 kGy. Prior and after treatments, and periodically during storage at 10 deg. C, total aerobic and total anerobic viable cell counts, and selectively, the viable cell counts of B. cereus and sulphite-reducing clostridia have been determined. The effects of the treatment order as well as addition of nisin to enhance the preservative efficiency of the physical treatments were also studied. Heat-sensitization of bacterial spores surviving irradiation occurred. The quality-friendly sous-vide cooking in combination with this medium dose gamma irradiation and/or nisin addition increased considerably the microbiological safety and the keeping quality of the meals studied. However, approx. 40% loss of thiamin content occurred as an effect of combination treatments, and adverse sensorial effects may also limit the feasible radiation doses or the usable concentrations of nisin.

  18. Improvement of microbiological safety of sous-vide meals by gamma radiation

    International Nuclear Information System (INIS)

    Farkas, J.; Polyak-Feher, K.; Andrassy, E.; Meszaros, L.

    2002-01-01

    Experimental batches of smoked-cured pork in stewed beans sauce were inoculated with spores of psychrotrophic Bacillus cereus, more heat and radiation resistant than spores of non-proteolytic C. botulinum. After vacuum packaging, the meals were treated with combinations of pasteurizing heat treatments and gamma irradiation of 5 kGy. Prior and after treatments, and periodically during storage at 10 deg. C, total aerobic and total anerobic viable cell counts, and selectively, the viable cell counts of B. cereus and sulphite-reducing clostridia have been determined. The effects of the treatment order as well as addition of nisin to enhance the preservative efficiency of the physical treatments were also studied. Heat-sensitization of bacterial spores surviving irradiation occurred. The quality-friendly sous-vide cooking in combination with this medium dose gamma irradiation and/or nisin addition increased considerably the microbiological safety and the keeping quality of the meals studied. However, approx. 40% loss of thiamin content occurred as an effect of combination treatments, and adverse sensorial effects may also limit the feasible radiation doses or the usable concentrations of nisin

  19. Shelf Life of Chicken Meat Balls Submitted to Sous Vide Treatment

    Directory of Open Access Journals (Sweden)

    ÖP Can

    2015-06-01

    Full Text Available The objective of this study was to investigate the appropriate temperature for processing storage of chicken meatballs made of minced chicken meat with the sous vide method. The chicken meatballs were prepared and separated into four experimental groups according to the application of heat treatment (10 and 20 minutes and storage time (+2 and +10°C. Sensory, microbiological (total aerobic mesophilic bacteria, total psychrotrophs, lactic acidbacteria, Enterobacteriaceae, Clostridiumperfringens, Listeria spp., chemical (pH, thiobarbituric acid, color (L*, a*, b* values, and texture profile analyses were performed on meatball samples. Cl. perfringens and Listeria spp. were not detected in meatball samples during the storage period. Samples cooked at 10 minute and stored at +2°C the highest count of total aerobic mesophilic bacteria (p<0.05. For lipid oxidation, interaction was observed between cooking time and storage temperature, with higher TBARs values for samples stored at 10 °C, while cooking time and storage temperature showed no influence on the color and textural analysis parameters. For the treatments evaluated, cooking time x storage temperature seem affect more microbiological and chemical parameters than color and textural parameters of chicken meatballs.

  20. Fuel elements for pressurised-gas reactors; Elements combustibles des piles a gaz sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Stohr, J A; Englander, M; Gauthron, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The design and fabrication of fuel elements for the first CO{sub 2} pressurized reactors have induced to investigate: various cladding materials, natural uranium base fuels, canning processes. The main analogical tests used in connection with the fuel element study are described. These various tests have enabled, among others, the fabrication of the fuel element for the EL2 reactor. Lastly, future solutions for electrical power producing reactors are foreseen. (author)Fren. [French] L'etude et la realisation d'elements combustibles pour les premieres piles a CO{sub 2} sous pression ont conduit a examiner: les divers materiaux de gaine, les combustibles a base d'uranium naturel, les modes de gainage. Les principaux essais analogiques ayant servi au cours de l'etude de la cartouche sont decrits. Ces divers essais ont notamment permis la realisation de la cartouche de la pile EL2. Enfin sont envisagees les solutions futures pour les piles productrices d'energie electrique. (auteur)

  1. Installation for analytic chemistry under irradiation; Installation de chimie analytique sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Fradin, J; Azoeuf, P; Guillon, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    An installation has been set up for carrying out manipulations and chemical analyses on radioactive products. It is completely remote-controlled and is of linear shape, 15 metres long; it is made up of three zones: - an active zone containing the apparatus, - a rear zone giving access to the active zone, - a forward zone independent of the two others and completely protected from which the remote-control of the apparatus is effected. The whole assembly has been designed so that each apparatus corresponding to an analytical technique is set up in a sealed enclosure. The sealed enclosures are interconnected by a conveyor. After three years operation, a critical review is now made of the installation. (authors) [French] L'installation a ete realisee pour effectuer des manipulations et des analyses chimiques sur des produits radioactifs. Elle est totalement telecommandee et se presente sous une forme lineaire de 15 metres de longueur et comporte trois zones: - une zone active d'appareillage, - une zone arriere d'intervention, - une zone avant independante des deux premieres et totalement protegee, ou s'operent les telecommandes de l'appareillage. L'ensemble a ete concu de facon a ce que chaque appareillage correspondant a une technique d'analyse soit implante dans une enceinte etanche. Les enceintes etanches sont reliees entre elles par un convoyeur. Apres trois annees de fonctionnement nous faisons le bilan et les critiques de l'installation. (auteurs)

  2. Corrosion Evaluation and Corrosion Control of Steam Generators

    International Nuclear Information System (INIS)

    Maeng, W. Y.; Kim, U. C.; Sung, K. W.; Na, J. W.; Lee, Y. H.; Lee, D. H.; Kim, K. M.

    2008-06-01

    Corrosion damage significantly influences the integrity and efficiency of steam generator. Corrosion problems of steam generator are unsolved issues until now even though much effort is made around world. Especially the stress corrosion cracking of heat exchange materials is the first issue to be solved. The corrosion protection method of steam generator is important and urgent for the guarantee of nuclear plant's integrity. The objectives of this study are 1) to evaluate the corrosion properties of steam generator materials, 2) to optimize the water chemistry of steam generator and 3) to develop the corrosion protection method of primary and secondary sides of steam generator. The results will be reflected to the water chemistry guideline for improving the integrity and efficiency of steam generator in domestic power plants

  3. Stress corrosion and corrosion fatigue crack growth monitoring in metals

    International Nuclear Information System (INIS)

    Senadheera, T.; Shipilov, S.A.

    2003-01-01

    Environmentally assisted cracking (including stress corrosion cracking and corrosion fatigue) is one of the major causes for materials failure in a wide variety of industries. It is extremely important to understand the mechanism(s) of environmentally assisted crack propagation in structural materials so as to choose correctly from among the various possibilities-alloying elements, heat treatment of steels, parameters of cathodic protection, and inhibitors-to prevent in-service failures due to stress corrosion cracking and corrosion fatigue. An important step towards understanding the mechanism of environmentally assisted crack propagation is designing a testing machine for crack growth monitoring and that simultaneously provides measurement of electrochemical parameters. In the present paper, a direct current (DC) potential drop method for monitoring crack propagation in metals and a testing machine that uses this method and allows for measuring electrochemical parameters during stress corrosion and corrosion fatigue crack growth are described. (author)

  4. Corrosion Evaluation and Corrosion Control of Steam Generators

    Energy Technology Data Exchange (ETDEWEB)

    Maeng, W. Y.; Kim, U. C.; Sung, K. W.; Na, J. W.; Lee, Y. H.; Lee, D. H.; Kim, K. M

    2008-06-15

    Corrosion damage significantly influences the integrity and efficiency of steam generator. Corrosion problems of steam generator are unsolved issues until now even though much effort is made around world. Especially the stress corrosion cracking of heat exchange materials is the first issue to be solved. The corrosion protection method of steam generator is important and urgent for the guarantee of nuclear plant's integrity. The objectives of this study are 1) to evaluate the corrosion properties of steam generator materials, 2) to optimize the water chemistry of steam generator and 3) to develop the corrosion protection method of primary and secondary sides of steam generator. The results will be reflected to the water chemistry guideline for improving the integrity and efficiency of steam generator in domestic power plants.

  5. Scanning reference electrode techniques in localized corrosion

    International Nuclear Information System (INIS)

    Isaacs, H.S.; Vyas, B.

    1979-04-01

    The principles, advantages, and implementations of scanning reference electrode techniques are reviewed. Data related to pitting, intergranular corrosion, welds and stress corrosion cracking are presented. The technique locates the position of localized corrosion and can be used to monitor the development of corrosion and changes in the corrosion rate under a wide range of conditions

  6. Corrosion control for low-cost reliability

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This conference was held September 19-24, 1993 in Houston, Texas to provide a forum for exchange of state-of-the-art information on corrosion. Topics of interest focus on the following: atmospheric corrosion; chemical process industry corrosion; high temperature corrosion; and corrosion of plant materials. Individual papers have been processed separately for inclusion in the appropriate data bases

  7. CHECWORKS integrated software for corrosion control

    International Nuclear Information System (INIS)

    Schefski, C.; Pietralik; Hazelton, T.

    1997-01-01

    CHECWORKS, a comprehensive software package for managing Flow-Accelerated Corrosion (FAC, also called erosion-corrosion and flow-assisted corrosion) concerns, is expanding to include other systems and other aspects of corrosion control in CANDU reactors. This paper will outline CHECWORKS applications at various CANDU stations and further plans for CHECWORKS to become a code for comprehensive corrosion control management. (author)

  8. Les tuméfactions sous mandibulaires: à propos de 42 cas et revue de la literature

    Science.gov (United States)

    Darouassi, Youssef; Mliha Touati, Mohamed; Chihani, Mehdi; Nadour, Karim; Ammar, Haddou; Bouaity, Brahim

    2014-01-01

    Les tuméfactions de la région sous mandibulaire sont une entité pathologique fréquente, caractérisées par un tableau clinique et une démarche diagnostique stéréotypée, et une unicité presque constante au plan chirurgical. Notre travail est une étude rétrospective sur une période de 5 an d'une série consécutive de 42 cas de tuméfactions sous mandibulaires qui ont été colligés au service d'oto-rhino-laryngologie et de chirurgie cervico-faciale de l'hôpital militaire Avicenne de Marrakech. L’âge moyen des patients était de 41 ans. Une prédominance masculine a été retrouvée. Le tableau clinique a été dominé par la tuméfaction sous mandibulaire. Tous les patients ont bénéficié d'une échographie cervicale. La tomodensitométrie cervicale a été réalisée chez 7 patients. La première étiologie était la sous maxillite chronique lithiasique dans 39,02% des cas. Le traitement était chirurgical dans tous les cas. En comparant les résultats avec ceux rapportés dans la littérature, nous allons discuter les différents aspects diagnostiques et thérapeutiques des étiologies les plus fréquentes. Les tuméfactions de la région sous mandibulaire sont fréquentes, nécessitant une démarche diagnostique rigoureuse et une prise en charge thérapeutique adaptée. PMID:25469195

  9. Corrosion of copper by chlorine trifluoride; Corrosion du cuivre par le trifluorure de chlore

    Energy Technology Data Exchange (ETDEWEB)

    Vincent, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    chlore a ete effectuee, et controlee par chromatographie gazeuse, microsublimation et spectrographie infra-rouge. Les essais ont porte sur des cuivres de differentes puretes, principalement sur le cuivre a 99,999, sous forme de monocristaux. Ils ont comporte des cinetiques et la caracterisation des produits de corrosion dans differentes conditions de temperature et de pression. Les cinetiques ont montre des reactions du meme ordre de grandeur que celles obtenues avec le fluor-element. A pression atmospherique, il se forme du fluorure cuivrique et du chlorure cuivreux. La presence de ce compose permet d'ecarter definitivement l'assimilation du ClF{sub 3} a un simple agent fluorant. Aux basses pressions, un compose inconnu a ete caracterise. Il existe une tres forte presomption pour qu'il s'agisse du fluorure cuivreux instable, qui n'a pas pu etre encore isole. Un phenomene de germination a ete mis en evidence, montrant les analogies des phases initiales de fluoration avec celles de l'oxydation. Des effets importants resultant de la dissociation des fluorures de cuivre et de la solubilite du chlore dans ce metal ont ete mis en evidence. En dernier lieu, des essais ont montre l'influence considerable de la purete de la phase gazeuse et de la nature des parois sur les vitesses de corrosion qui peuvent dans certains cas etre multipliees par plusieurs puissances de dix. (auteur)

  10. Anti-Corrosion Coating

    Science.gov (United States)

    1986-01-01

    SuperSpan RM 8000 is an anti-corrosion coating which effectively counteracts acid degradation, abrasive wear, and cracking in power industry facilities. It was developed by RM Industrial Products Company, Inc. with NERAC assistance. It had previously been necessary to shut down plants to repair or replace corroded duct-work in coal burning utilities. NASA-developed technology was especially useful in areas relating to thermoconductivity of carbon steel and the bonding characteristics of polymers. The product has sold well.

  11. Corrosion in power engineering

    International Nuclear Information System (INIS)

    1988-03-01

    The proceedings contain the full texts of 25 papers of which 10 fall under the INIS Subject Scope. They concern the problems of corrosion in WWER type nuclear power plants. The topics include structural materials and equipment of the primary and the secondary circuits of nuclear power plants, components used in disposal of spent nuclear fuel, sodium valves for fast reactors and basic study of the properties of materials used in nuclear power. (Z.M.). 12 figs., 6 tabs., 46 refs

  12. Air corrosion in storing

    International Nuclear Information System (INIS)

    Mazaudier, F.; Feron, D.; Baklouti, M.; Midoux, N.

    2001-01-01

    The air corrosiveness of a radioactive waste package has been estimated in a store inside which the environmental conditions are supposed to be rather close to the outside ones. It is expressed according to the ISO 9223 standard, from the humidification value and the amounts of sulfur dioxide and chlorine ions. A computer code has been perfected too; the thermal behaviour of the package can then been determined. (O.M.)

  13. Corrosion Protection of Aluminum

    Science.gov (United States)

    Dalrymple, R. S.; Nelson, W. B.

    1963-07-01

    Treatment of aluminum-base metal surfaces in an autoclave with an aqueous chromic acid solution of 0.5 to 3% by weight and of pH below 2 for 20 to 50 hrs at 160 to 180 deg C produces an extremely corrosion-resistant aluminum oxidechromium film on the surface. A chromic acid concentration of 1 to 2% and a pH of about 1 are preferred.

  14. Corrosion of beryllium oxide

    International Nuclear Information System (INIS)

    Elston, J.; Caillat, R.

    1958-01-01

    Data are reported on the volatilization rate of beryllium oxide in moist air depending on temperature and water vapour concentration. They are concerned with powder samples or sintered shapes of various densities. For sintered samples, the volatilization rate is very low under the following conditions: - temperature: 1300 deg. C, - water vapour concentration in moist air: 25 g/m 3 , - flow rate: 12 I/hour corresponding to a speed of 40 m/hour on the surface of the sample. For calcinated powders (1300 deg. C), grain growth has been observed under a stream of moist air at 1100 deg. C. For instance, grain size changes from 0,5 to at least 2 microns after 500 hours of exposure at this temperature. Furthermore, results data are reported on corrosion of sintered beryllium oxide in pressurized water. At 250 deg. C, under a pressure of 40 kg/cm 2 water is very slightly corrosive; however, internal strains are revealed. Finally, some features on the corrosion in liquid sodium are exposed. (author) [fr

  15. Zircaloy-4 corrosion in PWR's

    International Nuclear Information System (INIS)

    Fyfitch, S.; Smalley, W.R.; Roberts, E.

    1985-01-01

    Zircaloy-4 waterside corrosion has been studied extensively in the nuclear industry for a number of years. Following the early crud-related corrosion failures in the Saxton test reactor, Westinghouse undertook numerous programs to minimize crud deposition on fuel rods in power reactors through primary coolant chemistry control. Modern plants today are operating with improved coolant chemistry guidelines, and crud deposition levels are very low in proportion to earlier experience. Zircaloy-4 corrosion under a variety of coolant chemistry, heat flux and exposure conditions has been studied extensively. Experience to date, even in relatively high coolant temperature plants, has indicated that -for both fuel cladding and structural components- Zircaloy-4 waterside corrosion performance has been excellent. Recognizing future industry trends, however, which will result in Zircaloy-4 being subjected to ever increasing corrosion duties, Westinghouse will continue accumulating Zircaloy-4 corrosion experience in large power plants. 13 refs.

  16. Nuclear corrosion science and engineering

    CERN Document Server

    2012-01-01

    Understanding corrosion mechanisms, the systems and materials they affect, and the methods necessary for accurately measuring their incidence is of critical importance to the nuclear industry for the safe, economic and competitive running of its plants. This book reviews the fundamentals of nuclear corrosion. Corrosion of nuclear materials, i.e. the interaction between these materials and their environments, is a major issue for plant safety as well as for operation and economic competitiveness. Understanding these corrosion mechanisms, the systems and materials they affect, and the methods to accurately measure their incidence is of critical importance to the nuclear industry. Combining assessment techniques and analytical models into this understanding allows operators to predict the service life of corrosion-affected nuclear plant materials, and to apply the most appropriate maintenance and mitigation options to ensure safe long term operation. This book critically reviews the fundamental corrosion mechani...

  17. Pipe Lines – External Corrosion

    Directory of Open Access Journals (Sweden)

    Dan Babor

    2008-01-01

    Full Text Available Two areas of corrosion occur in pipe lines: corrosion from the medium carried inside the pipes; corrosion attack upon the outside of the pipes (underground corrosion. Electrolytic processes are also involved in underground corrosion. Here the moisture content of the soil acts as an electrolyte, and the ions required to conduct the current are supplied by water-soluble salts (chlorides, sulfates, etc. present in the soil. The nature and amount of these soluble materials can vary within a wide range, which is seen from the varying electrical conductivity and pH (varies between 3 and 10. Therefore the characteristics of a soil will be an important factor in under-ground corrosion.

  18. Accelerated Stress-Corrosion Testing

    Science.gov (United States)

    1986-01-01

    Test procedures for accelerated stress-corrosion testing of high-strength aluminum alloys faster and provide more quantitative information than traditional pass/fail tests. Method uses data from tests on specimen sets exposed to corrosive environment at several levels of applied static tensile stress for selected exposure times then subsequently tensile tested to failure. Method potentially applicable to other degrading phenomena (such as fatigue, corrosion fatigue, fretting, wear, and creep) that promote development and growth of cracklike flaws within material.

  19. Corrosion of fuel assembly materials

    International Nuclear Information System (INIS)

    Noe, M.; Frejaville, G.; Beslu, P.

    1985-08-01

    Corrosion of zircaloy-4 is reviewed in relation with previsions of improvement in PWRs performance: higher fuel burnup; increase coolant temperature, implying nucleate boiling on the hot clad surfaces; increase duration of the cycle due to load-follow operation. Actual knowledge on corrosion rates, based partly on laboratory tests, is insufficient to insure that external clad corrosion will not constitute a limitation to these improvements. Therefore, additional testing within representative conditions is felt necessary [fr

  20. Corrosion Monitors for Embedded Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Alex L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pfeifer, Kent B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Casias, Adrian L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sorensen, Neil R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Missert, Nancy A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-05-01

    We have developed and characterized novel in-situ corrosion sensors to monitor and quantify the corrosive potential and history of localized environments. Embedded corrosion sensors can provide information to aid health assessments of internal electrical components including connectors, microelectronics, wires, and other susceptible parts. When combined with other data (e.g. temperature and humidity), theory, and computational simulation, the reliability of monitored systems can be predicted with higher fidelity.

  1. Les enseignantes et enseignants sont-ils égaux face aux contraintes organisationnelles au sein des établissements du second degré ?

    OpenAIRE

    Cau-Bareille, Dominique

    2016-01-01

    Cet article présente une partie des résultats d’une recherche-action menée en France dans le champ de l’enseignement du second degré à la demande de deux syndicats. Celle-ci visait à comprendre les rapports de genre au sein des établissements et à éclairer les problèmes de harcèlement au travail évoqués plutôt par des femmes. Nous aborderons ici cette problématique sous l’angle des formes d’engagements dans l’activité professionnelle, en croisant le modèle ergonomique de l’activité de travail...

  2. Evaluation of steel corrosion by numerical analysis

    OpenAIRE

    Kawahigashi, Tatsuo

    2017-01-01

    Recently, various non-destructive and numerical methods have been used and many cases of steel corrosion are examined. For example, methods of evaluating corrosion through various numerical methods and evaluating macrocell corrosion and micro-cell corrosion using measurements have been proposed. However, there are few reports on estimating of corrosion loss with distinguishing the macro-cell and micro-cell corrosion and with resembling an actuality phenomenon. In this study, for distinguishin...

  3. Sigand : une application SIG sous androïd (tablette de la gestion des chantiers

    Directory of Open Access Journals (Sweden)

    CHAKIB SAFAR BATI

    2016-12-01

    Full Text Available L’introduction de données terrain pour les études environnementales ou de gestion de l’espace, régionales ou locales est une nécessité incontournable pour la validation des traitements et des interprétations mais aussi pour fournir des compléments d’informations aux divers travaux. Mais ce retour terrain est également de plus en plus demandé pour les gestionnaires de chantiers et de projets qui ont une exigence de contrôle ou de suivi et donc d’une information temps réel sur l’avancement des travaux, autrement pour introduire de nouvelles informations sur la base de données géoréférencées. Les avancées technologiques en matière de manipulation de l’information géographique (GPS, tablette graphique, téléphone portable, réalité augmentée permettent d’espérer la mise à dispositiondes professionnels, voire d’un plus large public, des outils adéquats pour de tels travaux. Actuellement, les outils d’élaboration, de gestion et d’exploitation des bases de données géographiques (solutions SIG ne sont pas encore complètement opérationnels en version « tablette » ; des applications telles que Qgis ou ArcGis sous Androïd attendent encore des développements. Nous présentons ici la première version d’une application SIG sous Androïd (disponible sur tablette pour la gestion en temps réel des chantiers qui permet de charger des couches vectorielles et de les mettre à jour sur le terrain en fonction de l’observation directe ; les couches (préalablement géoréférencées sont projetées sur des fonds cartographiques fournis par un serveur cartographique Google Maps (Route, Satellite, terrain; dans le cas d’absence de connexion internet, le fond cartographique est ramené d’un cache. Nous utilisons SpatialiteAndroïd pour le stockage et la manipulation des données géographiques. Le contrôleur de cartes Google Maps est employé pour afficher en mode cartographique les données stockées dans

  4. High pressure experimental water loop; Cellule experimentale a eau sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Grenon, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Terny, M [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France)

    1958-07-01

    A high pressure experimental water loop has been made for studying the detection and evolution of cladding failure in a pressurized reactor. The loop has been designed for a maximum temperature of 360 deg. C, a maximum of 160 kg/cm{sup 2} and flow rates up to 5 m{sup 3}/h. The entire loop consists of several parts: a main circuit with a canned rotor circulation pump, steam pressurizer, heating tubes, two hydro-cyclones (one de-gasser and one decanter) and one tubular heat exchanger; a continuous purification loop, connected in parallel, comprising pressure reducing valves and resin pots which also allow studies of the stability of resins under pressure, temperature and radiation; following the gas separator is a gas loop for studying the recombination of the radiolytic gases in the steam phase. The preceding circuits, as well as others, return to a low pressure storage circuit. The cold water of the low pressure storage flask is continuously reintroduced into the high pressure main circuit by means of a return pump at a maximum head of 160 kg /cm{sup 2}, and adjusted to the pressurizer level. This loop is also a testing bench for the tight high pressure apparatus. The circulating pump and the connecting flanges (Oak Ridge type) are water-tight. The feed pump and the pressure reducing valves are not; the un-tight ones have a system of leak recovery. To permanently check the tightness the circuit has been fitted with a leak detection system (similar to the HRT one). (author)Fren. [French] Une cellule experimentale a eau sous pression a ete realisee pour l'etude de l'evolution et de la detection de ruptures de gaines dans le cas d'un reacteur pressurise. Les performances de ce circuit sont: 350 deg. C maximum pour la temperature et 160 kg/cm{sup 2} maximum pour la pression, le debit pouvant atteindre 5 m{sup 3}/h. Le circuit complet est constitue de plusieurs parties: un circuit principal avec pompe de circulation a rotor immerge, preiseur a vapeur, tubes chaudieres

  5. Investigation of persistent Multiplets at the EGS reservoir of Soultz-Sous-Forêts, France

    Science.gov (United States)

    Lengliné, O.; Cauchie, L.; Schmittbuhl, J.

    2017-12-01

    During the exploitation of geothermal reservoirs, abundant seismicity is generally observed, especially during phases of hydraulic stimulations. The induced seismicity at the Enhanced Geothermal System of Soultz-Sous-Forêts in France, has been thoroughly studied over the years of exploitation. The mechanism at its origin has been related to both fluid pressure increases during stimulation and aseismic creeping movements. The fluid-induced seismic events often exhibit a high degree of similarity and the mechanism at the origin of these repeated events is thought to be associated with slow slip process where asperities on the rupture zone act several times.To have a better understanding of the mechanisms associated with such events and on the damaged zones involved during the hydraulic stimulations, we investigate the behavior of the multiplets and their persistent nature over several water injection intervals. For this purpose, we analyzed large datasets recorded from a borehole seismic network for several water injection periods (1993, 2000). For each stimulation interval, thousands of events are recorded at depth. We detected the events using a STA/LTA approach and classified them into families of comparable waveforms using an approach based on cross-correlation analysis. Classification of the seismic events is then improved depending on their location within the multiplets. For this purpose, inter-event distances within multiplets are examined and determined from cross-correlation analysis between pairs of events. These distances are then compared to the source dimensions derived from the estimation of the corner frequencies estimation. The multiplets properties (location, events size) are then investigated within and over several hydraulic tests. Hopefully these steps will lead to increase the knowledge on the repetitive nature of these events and the investigation of their persistence will outline the heterogeneities of the structures (regional stress

  6. Corrosion and stress corrosion cracking in supercritical water

    Science.gov (United States)

    Was, G. S.; Ampornrat, P.; Gupta, G.; Teysseyre, S.; West, E. A.; Allen, T. R.; Sridharan, K.; Tan, L.; Chen, Y.; Ren, X.; Pister, C.

    2007-09-01

    Supercritical water (SCW) has attracted increasing attention since SCW boiler power plants were implemented to increase the efficiency of fossil-based power plants. The SCW reactor (SCWR) design has been selected as one of the Generation IV reactor concepts because of its higher thermal efficiency and plant simplification as compared to current light water reactors (LWRs). Reactor operating conditions call for a core coolant temperature between 280 °C and 620 °C at a pressure of 25 MPa and maximum expected neutron damage levels to any replaceable or permanent core component of 15 dpa (thermal reactor design) and 100 dpa (fast reactor design). Irradiation-induced changes in microstructure (swelling, radiation-induced segregation (RIS), hardening, phase stability) and mechanical properties (strength, thermal and irradiation-induced creep, fatigue) are also major concerns. Throughout the core, corrosion, stress corrosion cracking, and the effect of irradiation on these degradation modes are critical issues. This paper reviews the current understanding of the response of candidate materials for SCWR systems, focusing on the corrosion and stress corrosion cracking response, and highlights the design trade-offs associated with certain alloy systems. Ferritic-martensitic steels generally have the best resistance to stress corrosion cracking, but suffer from the worst oxidation. Austenitic stainless steels and Ni-base alloys have better oxidation resistance but are more susceptible to stress corrosion cracking. The promise of grain boundary engineering and surface modification in addressing corrosion and stress corrosion cracking performance is discussed.

  7. Archaeological analogs and corrosion; Analogues archeologiques et corrosion

    Energy Technology Data Exchange (ETDEWEB)

    David, D

    2008-07-01

    In the framework of the high level and long life radioactive wastes disposal deep underground, the ANDRA built a research program on the material corrosion. In particular they aim to design containers for a very long time storage. Laboratory experiments are in progress and can be completed by the analysis of metallic archaeological objects and their corrosion after hundred years. (A.L.B.)

  8. Phytochemicals as Green Corrosion Inhibitors in Various Corrosive ...

    African Journals Online (AJOL)

    There is an intensive effort underway to develop new plant origin corrosion inhibitors for metal subjected to various environmental conditions. These efforts have been motivated by the desire to replace toxic inhibitors used for mitigation of corrosion of various metals and alloys in aqueous solutions. Plants represent a class ...

  9. Shadow Corrosion Mechanism of Zircaloy

    International Nuclear Information System (INIS)

    Ullberg, Mats; Lysell, Gunnar; Nystrand, Ann-Charlotte

    2004-02-01

    Local corrosion enhancement appears on zirconium-base alloys in-core in boiling water reactors when the zirconium alloy is in close proximity to another metal. The visual appearance often resembles a shadow of the other component. The phenomenon is therefore referred to as 'shadow corrosion'. Shadow corrosion has been known for more than 25 years. Mechanisms based on either galvanic corrosion or local radiolysis effects have been proposed as explanations. Both types of mechanism have seemed to explain some facets of the phenomenon. Normally, shadow corrosion is of no practical significance. However, an enhanced and potentially serious form of shadow corrosion was discovered in 1996. This discovery stimulated new experiments that fully supported neither of the longstanding theories. Thus, there is till now no generally accepted understanding of the shadow corrosion phenomenon. The aim of the present investigation was to analyse the available data and to identify, if possible, a plausible mechanism of shadow corrosion. It was found that the experimental evidence is, with a few exceptions, remarkably consistent with a galvanic mechanism. The main exception is that shadow corrosion may occur also when the two metals are nominally electrically insulated. One way to account for the main exception could be to invoke the effect of photoconductivity. Photoconductivity results when a semiconductor or an insulator is irradiated with photons of UV or higher energy. The photons elevate electrons from the valence band to the conduction band, thereby raising the electron conductivity of the solid. In particular, photoconductivity lowers the electrical resistance of the normally insulating oxide on zirconium base alloys. Photoconductivity therefore also has the potential to explain why shadow corrosion is only seen in, or in proximity to, a nuclear reactor core. The suggested mechanism of shadow corrosion can be tested in a reasonably simple experiment in a research reactor

  10. General Corrosion and Localized Corrosion of Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon

    2004-10-01

    The waste package design for the License Application is a double-wall waste package underneath a protective drip shield (BSC 2004 [DIRS 168489]; BSC 2004 [DIRS 169480]). The purpose and scope of this model report is to document models for general and localized corrosion of the waste package outer barrier (WPOB) to be used in evaluating waste package performance. The WPOB is constructed of Alloy 22 (UNS N06022), a highly corrosion-resistant nickel-based alloy. The inner vessel of the waste package is constructed of Stainless Steel Type 316 (UNS S31600). Before it fails, the Alloy 22 WPOB protects the Stainless Steel Type 316 inner vessel from exposure to the external environment and any significant degradation. The Stainless Steel Type 316 inner vessel provides structural stability to the thinner Alloy 22 WPOB. Although the waste package inner vessel would also provide some performance for waste containment and potentially decrease the rate of radionuclide transport after WPOB breach before it fails, the potential performance of the inner vessel is far less than that of the more corrosion-resistant Alloy 22 WPOB. For this reason, the corrosion performance of the waste package inner vessel is conservatively ignored in this report and the total system performance assessment for the license application (TSPA-LA). Treatment of seismic and igneous events and their consequences on waste package outer barrier performance are not specifically discussed in this report, although the general and localized corrosion models developed in this report are suitable for use in these scenarios. The localized corrosion processes considered in this report are pitting corrosion and crevice corrosion. Stress corrosion cracking is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]).

  11. Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R; Darras, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l'alliage Mg-Zr se comporte nettement mieux que le magnesium pur et surtout que l

  12. Corrosion of magnesium and some magnesium alloys in gas cooled reactors; Corrosion du magnesium et de certains de ses alliages dans les piles refroidies par gaz

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R.; Darras, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The results of corrosion tests on magnesium and some magnesium alloys (Mg-Zr and Mg-Zr-Zn) in moist air (like G1 reactor) and in CO{sub 2}: (like G2, G3, EDF1 reactors) are reported. The maximum temperature for exposure of magnesium to moist air without any risk of corrosion is 350 deg. C. Indeed, the oxidation rate follows a linear law above 350 deg. C although it reaches a constant level and keeps on very low under 350 deg. C. However, as far as corrosion is concerned this temperature limit can be raised up to 500 deg. C if moist air is very slightly charged with fluorinated compounds. Under pressure of CO{sub 2}, these three materials oxidate much more slowly even if 500 deg. C is reached. The higher is the temperature, the higher is the constant level of the weight increase and the quicker is reached this one. However, Mg-Zr alloy behaves quite better than pure magnesium and especially than Mg-Zr-Zn alloy. (author)Fren. [French] On expose essentiellement les resultats d'etudes sur la corrosion du magnesium et de certains de ses alliages (Mg-Zr et Mg-Zr-Zn) dans l'air humide (cas de la pile G1) et dans le gaz carbonique (cas des piles G2, G3, EDF1, etc...). La temperature limite d'exposition du magnesium dans l'air humide sans risque de corrosion se situe a 350 deg. C; en effet l'oxydation a un caractere lineaire au-dessus de cette temperature, alors qu'elle atteint un palier et reste tres limitee au-dessous de 350 deg. C. Du point de vue de la corrosion, cette temperature limite d'emploi peut cependant etre elevee jusqu'a 500 deg. C si l'on introduit dans l'air humide de tres faibles teneurs de composes fluores. Dans le gaz carbonique sous pression, l'oxydation est beaucoup plus faible, meme jusqu'a 50g. C pour les trois materiaux: l'augmentation de poids atteint un palier d'autant plus eleve et ceci d'autant plus rapidement que la temperature est elle-meme plus elevee. Cependant, l

  13. Corrosion mapping in pipelines

    International Nuclear Information System (INIS)

    Zscherpel, U.; Alekseychuk, O.; Bellon, C.; Ewert, U.; Rost, P.; Schmid, M.

    2002-01-01

    In a joint research project, BASF AG and BAM analyzed the state of the art of tangential radiography of pipes and developed more efficient methods of evaluation. Various PC applications were developed and tested: 1. A program for routine evaluation of digital radiographic images. 2. 3D simulation of the tangential projection of pipes for common radiation sources and various different detectors. 3. Preliminary work on combined evaluation of digital projections and wall thickness changes in radiation direction resulted in a new manner of image display, i.e. the so-called 'corrosion mapping', in which the wall thickness is displayed as a 2D picture above the pipe surface [de

  14. Microbiologically Influenced Corrosion

    Science.gov (United States)

    2015-11-05

    high in water content, are less corrosive owing to their elevated viscosity and resulting low conductivity (᝺-7 S/cm) [30]. Asphaltenes and resins...wet surface to a water-wet surface. Sludge deposits are combinations of hydrocarbons, sand, clay , corTosion prod- ucts, and biomass that can reach 50...fine clay sun·ounded by a film of water. Under low flow conditions, these particles precipitate and form a sludge deposit. 27.4 TESTING 27 .4.1 A

  15. Corrosion of Ceramic Materials

    Science.gov (United States)

    Opila, Elizabeth J.; Jacobson, Nathan S.

    1999-01-01

    Non-oxide ceramics are promising materials for a range of high temperature applications. Selected current and future applications are listed. In all such applications, the ceramics are exposed to high temperature gases. Therefore it is critical to understand the response of these materials to their environment. The variables to be considered here include both the type of ceramic and the environment to which it is exposed. Non-oxide ceramics include borides, nitrides, and carbides. Most high temperature corrosion environments contain oxygen and hence the emphasis of this chapter will be on oxidation processes.

  16. Corrosion management in nuclear industry

    International Nuclear Information System (INIS)

    Kamachi Mudali, U.

    2012-01-01

    Corrosion is a major degradation mechanism of metals and alloys which significantly affects the global economy with an average loss of 3.5% of GDP of several countries in many important industrial sectors including chemical, petrochemical, power, oil, refinery, fertilizer etc. The demand for higher efficiency and achieving name plate capacity, in addition to ever increasing temperatures, pressures and complexities in equipment geometry of industrial processes, necessitate utmost care in adopting appropriate corrosion management strategies in selecting, designing, fabricating and utilising various materials and coatings for engineering applications in industries. Corrosion control and prevention is an important focus area as the savings achieved from practicing corrosion control and prevention would bring significant benefits to the industry. Towards this, advanced corrosion management strategies starting from design, manufacturing, operation, maintenance, in-service inspection and online monitoring are essential. At the Indira Gandhi Centre for Atomic Research (IGCAR) strategic corrosion management efforts have been pursued in order to provide solutions to practical problems emerging in the plants, in addition to innovative efforts to provide insight into mechanism and understanding of corrosion of various engineering materials and coatings. In this presentation the author highlights how the nuclear industry benefited from the practical approach to successful corrosion management, particularly with respect to fast breeder reactor programme involving both reactor and associated reprocessing plants. (author)

  17. New technologies - new corrosion problems

    International Nuclear Information System (INIS)

    Heitz, E.

    1994-01-01

    Adequate resistance of materials to corrosion is equally important for classical and for new technologies. This article considers the economic consequences of corrosion damage and, in addition to the long-known GNP orientation, presents a new approach to the estimation of the costs of corrosion and corrosion protection via maintenance and especially corrosion-related maintenance. The significance of ''high-tech'', ''medium-tech'' and ''low-tech'' material and corrosion problems is assessed. Selected examples taken from new technologies in the areas of power engineering, environmental engineering, chemical engineering, and biotechnology demonstrate the great significance of the problems. It is concluded that corrosion research and corrosion prevention technology will never come to an end but will constantly face new problems. Two technologies are of particular interest since they focus attention on new methods of investigation: microelectronics and final disposal of radioactive wastes. The article closes by considering the importance of the transfer of experience and technology. Since the manufacturs and operators of machines and plant do not generally have access to the very latest knowledge, they should be kept informed through advisory services, experimental studies, databases, and further education. (orig.) [de

  18. Corrosion inhibitors. Manufacture and technology

    International Nuclear Information System (INIS)

    Ranney, M.W.

    1976-01-01

    Detailed information is presented relating to corrosion inhibitors. Areas covered include: cooling water, boilers and water supply plants; oil well and refinery operations; fuel and lubricant additives for automotive use; hydraulic fluids and machine tool lubes; grease compositions; metal surface treatments and coatings; and general processes for corrosion inhibitors

  19. DPC materials and corrosion environments.

    Energy Technology Data Exchange (ETDEWEB)

    Ilgen, Anastasia Gennadyevna; Bryan, Charles R.; Teich-McGoldrick, Stephanie; Hardin, Ernest

    2014-10-01

    After an exposition of the materials used in DPCs and the factors controlling material corrosion in disposal environments, a survey is given of the corrosion rates, mechanisms, and products for commonly used stainless steels. Research needs are then identified for predicting stability of DPC materials in disposal environments. Stainless steel corrosion rates may be low enough to sustain DPC basket structural integrity for performance periods of as long as 10,000 years, especially in reducing conditions. Uncertainties include basket component design, disposal environment conditions, and the in-package chemical environment including any localized effects from radiolysis. Prospective disposal overpack materials exist for most disposal environments, including both corrosion allowance and corrosion resistant materials. Whereas the behavior of corrosion allowance materials is understood for a wide range of corrosion environments, demonstrating corrosion resistance could be more technically challenging and require environment-specific testing. A preliminary screening of the existing inventory of DPCs and other types of canisters is described, according to the type of closure, whether they can be readily transported, and what types of materials are used in basket construction.

  20. Long-term corrosion studies

    International Nuclear Information System (INIS)

    Gdowski, G.

    1998-01-01

    The scope of this activity is to assess the long-term corrosion properties of metallic materials under consideration for fabricating waste package containers. Three classes of metals are to be assessed: corrosion resistant, intermediate corrosion resistant, and corrosion allowance. Corrosion properties to be evaluated are general, pitting and crevice corrosion, stress-corrosion cracking, and galvanic corrosion. The performance of these materials will be investigated under conditions that are considered relevant to the potential emplacement site. Testing in four aqueous solutions, and vapor phases above them, and at two temperatures are planned for this activity. (The environmental conditions, test metals, and matrix are described in detail in Section 3.0.) The purpose and objective of this activity is to obtain the kinetic and mechanistic information on degradation of metallic alloys currently being considered for waste package containers. This information will be used to provide assistance to (1) waste package design (metal barrier selection) (E-20-90 to E-20-92), (2) waste package performance assessment activities (SIP-PA-2), (3) model development (E-20-75 to E-20-89). and (4) repository license application

  1. Fatigue and Corrosion in Metals

    CERN Document Server

    Milella, Pietro Paolo

    2013-01-01

    This textbook, suitable for students, researchers and engineers, gathers the experience of more than 20 years of teaching fracture mechanics, fatigue and corrosion to professional engineers and running experimental tests and verifications to solve practical problems in engineering applications. As such, it is a comprehensive blend of fundamental knowledge and technical tools to address the issues of fatigue and corrosion. The book initiates with a systematic description of fatigue from a phenomenological point of view, since the early signs of submicroscopic damage in few surface grains and continues describing, step by step, how these precursors develop to become mechanically small cracks and, eventually, macrocracks whose growth is governed by fracture mechanics. But fracture mechanics is also introduced to analyze stress corrosion and corrosion assisted fatigue in a rather advanced fashion. The author dedicates a particular attention to corrosion starting with an electrochemical treatment that mechanical e...

  2. IN DRIFT CORROSION PRODUCTS

    Energy Technology Data Exchange (ETDEWEB)

    D.M. Jolley

    1999-12-02

    As directed by a written development plan (CRWMS M&O 1999a), a conceptual model for steel and corrosion products in the engineered barrier system (EBS) is to be developed. The purpose of this conceptual model is to assist Performance Assessment Operations (PAO) and its Engineered Barrier Performance Department in modeling the geochemical environment within a repository drift, thus allowing PAO to provide a more detailed and complete in-drift geochemical model abstraction and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near-Field Environment (NFE) Revision 2 (NRC 1999). This document provides the conceptual framework for the in-drift corrosion products sub-model to be used in subsequent PAO analyses including the EBS physical and chemical model abstraction effort. This model has been developed to serve as a basis for the in-drift geochemical analyses performed by PAO. However, the concepts discussed within this report may also apply to some near and far-field geochemical processes and may have conceptual application within the unsaturated zone (UZ) and saturated zone (SZ) transport modeling efforts.

  3. Faulting mechanisms and stress regime at the European HDR site of Soultz-sous-Forets, France

    International Nuclear Information System (INIS)

    Cuenot, Nicolas; Charlety, Jean; Haessler, Henri; Dorbath, Louis

    2006-01-01

    The state of stress and its implications for shear on fault planes during fluid injection are crucial issues for the HDR (Hot Dry Rock) or EGS (Enhanced or Engineered Geothermal System) concept. This is especially true for hydraulic stimulation experiments, aimed at enhancing the connectivity of a borehole to the natural fracture network, since they tend to induce the shearing of fractures, which is controlled by the local stress regime. During the 2000 and 2003 stimulation tests at Soultz-sous-Forets, France, about 10,000 microearthquakes were located with a surface seismological network. Hundreds of double-couple (DC) focal mechanisms were automatically determined from first-motion polarities using the FPFIT program [Reasenberg, P.A., Oppenheimer, D., 1985. FPFIT, FPPLOT and FPPAGE: Fortran computer programs for calculating and displaying earthquake fault-plane solutions. US Geological Survey Open-File Report 85-739, 25 pp.]. The majority of these mechanisms indicate normal-faulting movement with a more or less pronounced strike-slip component. Some quasi-pure strike-slip events also occurred, especially in the deeper part of the stimulated rock volume, at more than 5 km depth. Although we found a double-couple solution for all events, we tried to observe and quantify the proportion of the non-double-couple (NDC) component in the seismic moment tensor for several microseisms from the 2003 data. The study shows that the NDC is higher for the events in the vicinity of the injection well than for the events far from the well. We used the method of Rivera and Cisternas [Rivera, L., Cisternas, A., 1990. Stress tensor and fault-plane solutions for a population of earthquakes. Bull. Seismol. Soc. Am. 80, 600-614.] to perform the inversion of the deviatoric part of the stress tensor from P-wave polarities. This method was applied to different datasets from the 2000 test, taken from the shallower and deeper parts of the stimulated region. The results show a stable

  4. Faulting mechanisms and stress regime at the European HDR site of Soultz-sous-Forets, France

    Energy Technology Data Exchange (ETDEWEB)

    Cuenot, Nicolas; Charlety, Jean; Haessler, Henri [Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre (IPGS-EOST), 5 rue Rene Descartes, 67084 Strasbourg Cedex (France); Dorbath, Louis [Institut de Physique du Globe de Strasbourg, Ecole et Observatoire des Sciences de la Terre (IPGS-EOST), 5 rue Rene Descartes, 67084 Strasbourg Cedex (France); Institut de Recherche pour le Developpement, Laboratoire des Mecanismes et Transferts en Geologie (IRD, LMTG), 14 Avenue Edouard Belin, 31400 Toulouse (France)

    2006-10-15

    The state of stress and its implications for shear on fault planes during fluid injection are crucial issues for the HDR (Hot Dry Rock) or EGS (Enhanced or Engineered Geothermal System) concept. This is especially true for hydraulic stimulation experiments, aimed at enhancing the connectivity of a borehole to the natural fracture network, since they tend to induce the shearing of fractures, which is controlled by the local stress regime. During the 2000 and 2003 stimulation tests at Soultz-sous-Forets, France, about 10,000 microearthquakes were located with a surface seismological network. Hundreds of double-couple (DC) focal mechanisms were automatically determined from first-motion polarities using the FPFIT program [Reasenberg, P.A., Oppenheimer, D., 1985. FPFIT, FPPLOT and FPPAGE: Fortran computer programs for calculating and displaying earthquake fault-plane solutions. US Geological Survey Open-File Report 85-739, 25 pp.]. The majority of these mechanisms indicate normal-faulting movement with a more or less pronounced strike-slip component. Some quasi-pure strike-slip events also occurred, especially in the deeper part of the stimulated rock volume, at more than 5 km depth. Although we found a double-couple solution for all events, we tried to observe and quantify the proportion of the non-double-couple (NDC) component in the seismic moment tensor for several microseisms from the 2003 data. The study shows that the NDC is higher for the events in the vicinity of the injection well than for the events far from the well. We used the method of Rivera and Cisternas [Rivera, L., Cisternas, A., 1990. Stress tensor and fault-plane solutions for a population of earthquakes. Bull. Seismol. Soc. Am. 80, 600-614.] to perform the inversion of the deviatoric part of the stress tensor from P-wave polarities. This method was applied to different datasets from the 2000 test, taken from the shallower and deeper parts of the stimulated region. The results show a stable

  5. Review of corrosion causes and corrosion control in a technical facility

    International Nuclear Information System (INIS)

    Charng, T.; Lansing, F.

    1982-06-01

    Causes of corrosion of metals and their alloys are reviewed. The corrosion mechanism is explained by electrochemical reaction theory. The causes and methods of controlling of both physiochemical corrosion and biological corrosion are presented. Factors which influence the rate of corrosion are also discussed

  6. Corrosion detection of nanowires by magnetic sensors

    KAUST Repository

    Kosel, Jü rgen; Amara, Selma; Ivanov, Iurii; Blanco, Mario

    2017-01-01

    Disclosed are various embodiments related to a corrosion detection device for detecting corrosive environments. A corrosion detection device comprises a magnetic sensor and at least one magnetic nanowire disposed on the magnetic sensor. The magnetic sensor is configured to detect corrosion of the one or more magnetic nanowires based at least in part on a magnetic field of the one or more magnetic nanowires.

  7. Recognition and Analysis of Corrosion Failure Mechanisms

    Directory of Open Access Journals (Sweden)

    Steven Suess

    2006-02-01

    Full Text Available Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, material evaluation, data review and conclusion procurement. In analyzing corrosion failures, one must recognize the wide range of common corrosion mechanisms. The features of any corrosion failure give strong clues as to the most likely cause of the corrosion. This article details a proven approach to properly determining the root cause of a failure, and includes pictographic illustrations of the most common corrosion mechanisms, including general corrosion, pitting, galvanic corrosion, dealloying, crevice corrosion, microbiologically-influenced corrosion (MIC, corrosion fatigue, stress corrosion cracking (SCC, intergranular corrosion, fretting, erosion corrosion and hydrogen damage.

  8. Corrosion detection of nanowires by magnetic sensors

    KAUST Repository

    Kosel, Jürgen

    2017-10-05

    Disclosed are various embodiments related to a corrosion detection device for detecting corrosive environments. A corrosion detection device comprises a magnetic sensor and at least one magnetic nanowire disposed on the magnetic sensor. The magnetic sensor is configured to detect corrosion of the one or more magnetic nanowires based at least in part on a magnetic field of the one or more magnetic nanowires.

  9. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  10. Improvement of PWR reliability by corrosion prevention

    International Nuclear Information System (INIS)

    Takamatsu, Hiroshi

    1999-01-01

    Since first PWR in Japan started commercial operation in 1970, we have encountered the various modes of corrosion on primary and secondary side components. We have paid much efforts for resolving these corrosion problems, that is, investigating the causes of corrosion and establishing the countermeasures for these corrosion. We summarize these efforts in this article. (author)

  11. 49 CFR 172.442 - CORROSIVE label.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false CORROSIVE label. 172.442 Section 172.442... SECURITY PLANS Labeling § 172.442 CORROSIVE label. (a) Except for size and color, the CORROSIVE label must... CORROSIVE label must be white in the top half and black in the lower half. [Amdt. 172-123, 56 FR 66259, Dec...

  12. Traduction audiovisuelle : quand le sous-titrage à destination des personnes sourdes et malentendantes se rencontrent dans le film "Le Prénom"

    OpenAIRE

    Horii, Anaïk

    2015-01-01

    La traduction audiovisuelle est riche en méthodes de traduction : doublage, voice over, sur-titrage, audiodescription, etc. Ce mémoire se concentre sur la méthode du sous-titrage ainsi que sur celle du sous-titrage à destination des personnes sourdes et malentendantes. Le but était de comparer ces deux méthodes de traduction interlinguistique (dans les deux cas pour un public germanophone) en s'attardant sur les références culturelles ainsi que sur les langages populaire, familier et argotiqu...

  13. Influence of Sous Vide and water immersion processing on polyacetylene content and instrumental color of parsnip (Pastinaca sativa) disks.

    Science.gov (United States)

    Rawson, Ashish; Koidis, Anastasios; Rai, Dilip K; Tuohy, Maria; Brunton, Nigel

    2010-07-14

    The effect of blanching (95 +/- 3 degrees C) followed by sous vide (SV) processing (90 degrees C for 10 min) on levels of two polyacetylenes in parsnip disks immediately after processing and during chill storage was studied and compared with the effect of water immersion (WI) processing (70 degrees C for 2 min.). Blanching had the greatest influence on the retention of polyacetylenes in sous vide processed parsnip disks resulting in significant decreases of 24.5 and 24% of falcarinol (1) and falcarindiol (2) respectively (p processing did not result in additional significant losses in polyacetylenes compared to blanched samples. Subsequent anaerobic storage of SV processed samples resulted in a significant decrease in 1 levels (p levels was observed (p > 0.05). 1 levels in WI processed samples were significantly higher than in SV samples (p processing with losses of up to 70% occurring after 5 days storage. 1 type polyacetylene undergoes degradation such as oxidation, dehydrogenation when thermally treated forming oxidized form of 1 type molecules, in this case falcarindione, dehydrofalcarinol, dehydrofalcarinone. Thermal processing had a significant effect on instrumental color of parsnip samples compared to minimally processed in both SV and WI processed samples resulting in parsnip disks becoming darker, yellower and browner following processing and storage.

  14. High temperature corrosion of metals

    International Nuclear Information System (INIS)

    Quadakkers, W.J.; Schuster, H.; Ennis, P.J.

    1988-08-01

    This paper covers three main topics: 1. high temperature oxidation of metals and alloys, 2. corrosion in sulfur containing environments and 3. structural changes caused by corrosion. The following 21 subjects are discussed: Influence of implanted yttrium and lanthanum on the oxidation behaviour of beta-NiA1; influence of reactive elements on the adherence and protective properties of alumina scales; problems related to the application of very fine markers in studying the mechanism of thin scale formation; oxidation behaviour of chromia forming Co-Cr-Al alloys with or without reactive element additions; growth and properties of chromia-scales on high-temperature alloys; quantification of the depletion zone in high temperature alloys after oxidation in process gas; effects of HC1 and of N2 in the oxidation of Fe-20Cr; investigation under nuclear safety aspects of Zircaloy-4 oxidation kinetics at high temperatures in air; on the sulfide corrosion of metallic materials; high temperature sulfide corrosion of Mn, Nb and Nb-Si alloys; corrosion behaviour or NiCrAl-based alloys in air and air-SO2 gas mixtures; sulfidation of cobalt at high temperatures; preoxidation for sulfidation protection; fireside corrosion and application of additives in electric utility boilers; transport properties of scales with complex defect structures; observations of whiskers and pyramids during high temperature corrosion of iron in SO2; corrosion and creep of alloy 800H under simulated coal gasification conditions; microstructural changes of HK 40 cast alloy caused by exploitation in tubes in steam reformer installation; microstructural changes during exposure in corrosive environments and their effect on mechanical properties; coatings against carburization; mathematical modeling of carbon diffusion and carbide precipitation in Ni-Cr-based alloys. (MM)

  15. Corrosion protection and control using nanomaterials

    CERN Document Server

    Cook, R

    2012-01-01

    This book covers the use of nanomaterials to prevent corrosion. The first section deals with the fundamentals of corrosion prevention using nanomaterials. Part two includes a series of case studies and applications of nanomaterials for corrosion control.$bCorrosion is an expensive and potentially dangerous problem in many industries. The potential application of different nanostructured materials in corrosion protection, prevention and control is a subject of increasing interest. Corrosion protection and control using nanomaterials explores the potential use of nanotechnology in corrosion control. The book is divided into two parts. Part one looks at the fundamentals of corrosion behaviour and the manufacture of nanocrystalline materials. Chapters discuss the impact of nanotechnology in reducing corrosion cost, and investigate the influence of various factors including thermodynamics, kinetics and grain size on the corrosion behaviour of nanocrystalline materials. There are also chapters on electrodeposition ...

  16. Experimental study of chemical-mechanical coupling during percolation of reactive fluid through rocks under stress, in the context of the CO{sub 2} geological sequestration; Etude experimentale du couplage chimie-mecanique lors de la percolation d'un fluide reactif dans des roches sous contrainte, dans le contexte de la sequestration geologique du CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, Y

    2006-10-15

    CO{sub 2} injection into geological repositories will induce chemical and mechanical instabilities. The study of these instabilities is based on experimental deformation of natural rock samples under stress, in the presence of fluids containing, or not, dissolved CO{sub 2}. Triaxial cells used for the experiments permitted an independent control and measurement of stress, temperature, fluid pressure and composition. Vertical strains were measured during several months, with a resolution of 1.10{sup -12} s{sup -1} on the strain rate. Simultaneously, fluids were analysed in order to quantify fluid-rock interactions. For limestone samples, percolation of CO{sub 2}-rich fluids increases strain rate by a factor 1.7 up to 5; on the other hand, sandstone deformation remained almost the same. Increase in strain rate with limestone samples was explained by injected water acidification by the CO{sub 2} which increases rock solubility and reaction kinetics. On the opposite, small effect of CO{sub 2} on quartz explains the absence of deformation. X-ray observations confirmed the importance of rock composition and structure on the porosity evolution. Numerical simulations of rock elastic properties showed increasing shear stress into the sample. Measured deformation showed an evolution of reservoir rocks mechanical properties. It was interpreted as the consequence of pressure solution mechanisms both at grains contacts and on grain free surfaces. (author)

  17. Stress, microstructure and evolution under ion irradiation in thin films grown by ion beam sputtering: modelling and application to interfacial effects in metallic multilayers; Contraintes, microstructure et sollicitation sous irradiation aux ions de films minces elabores par pulverisation ionique: modelisation et application a l'etude des effets interfaciaux dans des multicouches metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Debelle, A

    2006-09-15

    We have investigated the formation of the interfacial chemical mixing in Mo/Ni multilayers, and particularly the influence of ballistic effects during the growth. For this purpose, hetero-epitaxial b.c.c./f.c.c. Mo(110)/Ni(111) multilayers were grown by two deposition methods: thermal evaporation and direct ion beam sputtering. As a preliminary, an accurate description of the stress state in pure sputtered Mo thin films was required. Microstructural and stress state analyses were essentially carried out by X-ray diffraction, and ion irradiation was used as a powerful tool to control the stress level. We showed that thermal evaporated thin films exhibit a weak tensile growth stress ({approx} 0.6 GPa) that can be accounted for by the grain boundary relaxation model, whereas sputtered thin films develop large compressive growth stress (- 2 to - 4 GPa). This latter results from the bombardment of the growing film by the energetic particles involved during the sputtering process (atomic peening phenomenon), which induces the formation of defects in the layers, generating volume distortions. We thus developed a stress model that includes a hydrostatic stress component to account for these volume strains. This model allowed us to determine the 'unstressed and free of defects lattice parameter' a{sub 0}, solely linked to chemical effects. For epitaxial Mo layers, it was possible to separate coherency stress from growth stress due to their distinct kinetic evolution during ion irradiation. Therefore, the stress analysis enabled us to determine the a{sub 0} values in Mo sub-layers of Mo/Ni superlattices. A tendency to the formation of an interfacial alloy is observed independently of the growth conditions, which suggests that thermodynamic forces favour the exchange mechanism. However, the extent of the intermixing effect is clearly enhanced by ballistic effects. (author)

  18. Stress, microstructure and evolution under ion irradiation in thin films grown by ion beam sputtering: modelling and application to interfacial effects in metallic multilayers; Contraintes, microstructure et sollicitation sous irradiation aux ions de films minces elabores par pulverisation ionique: modelisation et application a l'etude des effets interfaciaux dans des multicouches metalliques

    Energy Technology Data Exchange (ETDEWEB)

    Debelle, A

    2006-09-15

    We have investigated the formation of the interfacial chemical mixing in Mo/Ni multilayers, and particularly the influence of ballistic effects during the growth. For this purpose, hetero-epitaxial b.c.c./f.c.c. Mo(110)/Ni(111) multilayers were grown by two deposition methods: thermal evaporation and direct ion beam sputtering. As a preliminary, an accurate description of the stress state in pure sputtered Mo thin films was required. Microstructural and stress state analyses were essentially carried out by X-ray diffraction, and ion irradiation was used as a powerful tool to control the stress level. We showed that thermal evaporated thin films exhibit a weak tensile growth stress ({approx} 0.6 GPa) that can be accounted for by the grain boundary relaxation model, whereas sputtered thin films develop large compressive growth stress (- 2 to - 4 GPa). This latter results from the bombardment of the growing film by the energetic particles involved during the sputtering process (atomic peening phenomenon), which induces the formation of defects in the layers, generating volume distortions. We thus developed a stress model that includes a hydrostatic stress component to account for these volume strains. This model allowed us to determine the 'unstressed and free of defects lattice parameter' a{sub 0}, solely linked to chemical effects. For epitaxial Mo layers, it was possible to separate coherency stress from growth stress due to their distinct kinetic evolution during ion irradiation. Therefore, the stress analysis enabled us to determine the a{sub 0} values in Mo sub-layers of Mo/Ni superlattices. A tendency to the formation of an interfacial alloy is observed independently of the growth conditions, which suggests that thermodynamic forces favour the exchange mechanism. However, the extent of the intermixing effect is clearly enhanced by ballistic effects. (author)

  19. Cracking and corrosion recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Suik, H. [Tallinn Technical University, Horizon Pulp and Paper, Tallinn (Estonia)

    1998-12-31

    The corrosion of heat surfaces and the cracking the drums are the main problems of the recovery boiler. These phenomena have been appeared during long-term operation of boiler `Mitsubishi - 315` erected at 1964. Depth of the crack is depending on the number of shutdowns and on operation time. Corrosion intensity of different heat surfaces is varying depend on the metal temperature and the conditions at place of positioning of tube. The lowest intensity of corrosion is on the bank tubes and the greatest is on the tubes of the second stage superheater and on the tubes at the openings of air ports. (orig.) 5 refs.

  20. Corrosion-resistant coating development

    Energy Technology Data Exchange (ETDEWEB)

    Stinton, D.P.; Kupp, D.M.; Martin, R.L. [Oak Ridge National Lab., TN (United States)

    1997-12-01

    SiC-based heat exchangers have been identified as the prime candidate material for use as heat exchangers in advanced combined cycle power plants. Unfortunately, hot corrosion of the SiC-based materials created by alkali metal salts present in the combustion gases dictates the need for corrosion-resistant coatings. The well-documented corrosion resistance of CS-50 combined with its low (and tailorable) coefficient of thermal expansion and low modulus makes CS-50 an ideal candidate for this application. Coatings produced by gelcasting and traditional particulate processing have been evaluated.

  1. Cracking and corrosion recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Suik, H [Tallinn Technical University, Horizon Pulp and Paper, Tallinn (Estonia)

    1999-12-31

    The corrosion of heat surfaces and the cracking the drums are the main problems of the recovery boiler. These phenomena have been appeared during long-term operation of boiler `Mitsubishi - 315` erected at 1964. Depth of the crack is depending on the number of shutdowns and on operation time. Corrosion intensity of different heat surfaces is varying depend on the metal temperature and the conditions at place of positioning of tube. The lowest intensity of corrosion is on the bank tubes and the greatest is on the tubes of the second stage superheater and on the tubes at the openings of air ports. (orig.) 5 refs.

  2. Assessing resistance of stabilized corrosion resistant steels to intergranular corrosion

    International Nuclear Information System (INIS)

    Karas, A.; Cihal, V. Jr.; Vanek, V.; Herzan, J.; Protiva, K.; Cihal, V.

    1987-01-01

    Resistance to intergranular corrosion was determined for four types of titanium-stabilized steels from the coefficients of stabilization efficiency according to the degree the chemical composition was known. The ATA SUPER steel showed the highest resistance parameter value. The resistance of this type of steel of a specific composition, showing a relatively low value of mean nitrogen content was compared with steel of an optimized chemical composition and with low-carbon niobium stabilized, molybdenum modified steels. The comparison showed guarantees of a sufficient resistance of the steel to intergranular corrosion. The method of assessing the resistance to intergranular corrosion using the calculation of the minimum content of Cr', i.e., the effective chromium content, and the maximum effective carbon content C' giving the resistance parameter k seems to be prospective for practical use in the production of corrosion resistant steels. (author). 1 tab., 5 figs., 15 refs

  3. Corrosion and corrosion fatigue of airframe aluminum alloys

    Science.gov (United States)

    Chen, G. S.; Gao, M.; Harlow, D. G.; Wei, R. P.

    1994-01-01

    Localized corrosion and corrosion fatigue crack nucleation and growth are recognized as degradation mechanisms that effect the durability and integrity of commercial transport aircraft. Mechanically based understanding is needed to aid the development of effective methodologies for assessing durability and integrity of airframe components. As a part of the methodology development, experiments on pitting corrosion, and on corrosion fatigue crack nucleation and early growth from these pits were conducted. Pitting was found to be associated with constituent particles in the alloys and pit growth often involved coalescence of individual particle-nucleated pits, both laterally and in depth. Fatigue cracks typically nucleated from one of the larger pits that formed by a cluster of particles. The size of pit at which fatigue crack nucleates is a function of stress level and fatigue loading frequency. The experimental results are summarized, and their implications on service performance and life prediction are discussed.

  4. pitting corrosion susceptibility pitting corrosion susceptibility of aisi

    African Journals Online (AJOL)

    eobe

    2DEPARTMENT OF MECHANICAL ENGINEERING, UNIVERSITY OF BENIN, BENIN- CITY, EDO STATE, NIGERIA. E-mail addresses: ... fluids and aggressive chemicals. Pitting corrosion ... the kitchen, food manufacturing and dispensing and.

  5. Corrosion resistant ceramic materials

    Science.gov (United States)

    Kaun, T.D.

    1996-07-23

    Ceramic materials are disclosed which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200--550 C or organic salt (including SO{sub 2} and SO{sub 2}Cl{sub 2}) at temperatures of 25--200 C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components. 1 fig.

  6. Mortar fights acid corrosion

    Energy Technology Data Exchange (ETDEWEB)

    1982-05-14

    The burning of coal or oil to produce heat required to operate a power boiler also generates a severe corrosion problem within the interior of the duct and stacks used to emit the flue gas into the atmosphere. How can concrete and steel be protected from the effects of acid attack, when the acids are carried in a gas form, or come into direct contact with the steel or concrete from spillage or immersion conditions. Industry in North America has found that the solution to this problem is to build an outside concrete column, in this case of Portland cement, and inside that column, build a totally independent brick liner bonded with Sauereisen mortar.

  7. Erosion--corrosion

    International Nuclear Information System (INIS)

    Vyas, B.

    1978-01-01

    The deterioration of materials by corrosion or erosion by itself presents a formidable problem and for this reason investigators have studied these two phenomena independently. In fact, there are very few systematic studies on E-C and the majority of references mention it only in passing. In most real systems, however, the two destructive processes take place simultaneously, hence the purpose of this review is to present the various interactions between the chemical and mechanical agents leading to accelerated degradation of the material. The papers cited in the review are those that lead to a better understanding of the process involved in the accelerated rate of material loss under E-C conditions

  8. Corrosion resistant ceramic materials

    Science.gov (United States)

    Kaun, Thomas D.

    1996-01-01

    Ceramic materials which exhibit stability in severely-corrosive environments having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These sulfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

  9. Critical Study of Corrosion Damaged Concrete Structures

    OpenAIRE

    Sallehuddin Shah Ayop; John Cairns

    2013-01-01

    Corrosion of steel reinforcement in concrete is one of the major problems with respect to the durability of reinforced concrete structures. The degradation of the structure strength due to reinforcement corrosion decreases its design life. This paper presents the literature study on the influence of the corrosion on concrete structure starting from the mechanism of the corrosion until the deterioration stage and the structural effects of corrosion on concrete structures.

  10. Corrosion testing and prediction in SCWO environments

    International Nuclear Information System (INIS)

    Kriksunov, L.B.; Macdonald, D.D.

    1995-01-01

    The authors review recent advances in corrosion monitoring and modeling in SCWO systems. Techniques and results of experimental corrosion measurements at high temperatures are presented. Results of modeling corrosion in high subcritical and supercritical aqueous systems indicate the primary importance of density of water in corrosion processes. A phenomenological model has been developed to simulate corrosion processes at nearcritical and supercritical temperatures in SCWO systems. They discuss as well the construction of Pourbaix diagrams for metals in SCW

  11. Review on stress corrosion and corrosion fatigue failure of centrifugal compressor impeller

    Science.gov (United States)

    Sun, Jiao; Chen, Songying; Qu, Yanpeng; Li, Jianfeng

    2015-03-01

    Corrosion failure, especially stress corrosion cracking and corrosion fatigue, is the main cause of centrifugal compressor impeller failure. And it is concealed and destructive. This paper summarizes the main theories of stress corrosion cracking and corrosion fatigue and its latest developments, and it also points out that existing stress corrosion cracking theories can be reduced to the anodic dissolution (AD), the hydrogen-induced cracking (HIC), and the combined AD and HIC mechanisms. The corrosion behavior and the mechanism of corrosion fatigue in the crack propagation stage are similar to stress corrosion cracking. The effects of stress ratio, loading frequency, and corrosive medium on the corrosion fatigue crack propagation rate are analyzed and summarized. The corrosion behavior and the mechanism of stress corrosion cracking and corrosion fatigue in corrosive environments, which contain sulfide, chlorides, and carbonate, are analyzed. The working environments of the centrifugal compressor impeller show the behavior and the mechanism of stress corrosion cracking and corrosion fatigue in different corrosive environments. The current research methods for centrifugal compressor impeller corrosion failure are analyzed. Physical analysis, numerical simulation, and the fluid-structure interaction method play an increasingly important role in the research on impeller deformation and stress distribution caused by the joint action of aerodynamic load and centrifugal load.

  12. Metallurgy of stress corrosion cracking

    International Nuclear Information System (INIS)

    Donovan, J.A.

    1973-01-01

    The susceptibility of metals and alloys to stress corrosion is discussed in terms of the relationship between structural characteristics (crystal structure, grains, and second phases) and defects (vacancies, dislocations, and cracks) that exist in metals and alloys. (U.S.)

  13. Heated Aluminum Tanks Resist Corrosion

    Science.gov (United States)

    Johnson, L. E.

    1983-01-01

    Simple expedient of heating foam-insulated aluminum alloy tanks prevents corrosion by salt-laden moisture. Relatively-small temperature difference between such tank and surrounding air will ensure life of tank is extended by many years.

  14. Corrosion resistant neutron absorbing coatings

    Science.gov (United States)

    Choi, Jor-Shan [El Cerrito, CA; Farmer, Joseph C [Tracy, CA; Lee, Chuck K [Hayward, CA; Walker, Jeffrey [Gaithersburg, MD; Russell, Paige [Las Vegas, NV; Kirkwood, Jon [Saint Leonard, MD; Yang, Nancy [Lafayette, CA; Champagne, Victor [Oxford, PA

    2012-05-29

    A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

  15. Dictionary corrosion and corrosion control. English-German/German-English. Fachwoerterbuch Korrosion und Korrosionsschutz. Englisch-Deutsch/Deutsch-Englisch

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    This dictionary has 13000 entries in both languages. Keywords and extensive accompanying information simplify the choice of word for the user. The following topics are covered: Theoretical principles of corrosion; Corrosion of the metals and alloys most frequently used in engineering. Types of corrosion - (chemical-, electro-chemical, biological corrosion); forms of corrosion (superficial, pitting, selective, intercrystalline and stress corrosion; vibrational corrosion cracking); erosion and cavitation. Methods of corrosion control (material selection, temporary corrosion protection media, paint and plastics coatings, electro-chemical coatings, corrosion prevention by treatment of the corrosive media); Corrosion testing methods.

  16. Determination of the Quality and Shelf Life of Sous Vide Cooked Turkey Cutlet Stored at 4 and 12ºC

    Directory of Open Access Journals (Sweden)

    IT Akoğlu

    Full Text Available ABSTRACT The aim of this study was to determine the quality and shelf life of sous vide turkey cutlet stored at 4 and 12ºC. Samples were packaged under vacuum into polyamide-polypropylene pouches, cooked using sous vide technology (65ºC/40 min, chilled at 3ºC and stored at 4 and 12ºC for 5 weeks. Microbial (TMAB, lactic acid bacteria, Enterobacteriaceae, moulds and yeasts, Salmonella spp., L. monocytogenes, Cl. perfringens, physical-chemical (pH, water activity, TBARS, L*a*b* colour, texture profile analysis and shear force and sensory (appearance, colour, odour, flavour, juiciness, chewiness and acceptance parameters were determined. According to the results of mesophilic bacterial counts and sensory analysis, the shelf life of the sous vide turkey cutlet, cooked at 65ºC for 40 min, was determined as 28 days at 4ºC while 15 days at 12ºC. Salmonella spp., L. monocytogenes, Cl. perfringens were not detected in turkey cutlet samples during the storage period. It was detected that sous vide cooked provided convenient ready-to-eat foods and a long shelf life for turkey cutlet.

  17. Change in physical and chemical characteristics related to the binomial time-temperature used in sous pasteurization see Tambaqui (Colossoma macropomum

    Directory of Open Access Journals (Sweden)

    H.C.A. Kato

    2016-02-01

    Full Text Available The goal of this study was to evaluate sous vide fish and assess the influence of time and temperature on the pasteurization process through quality parameters. The raw material (tambaqui fillets and the sous vide underwent physical, physicochemical, and microbiological analyses. A sauce was prepared containing soy sauce, water, horseradish and garlic flakes. The product's pasteurization parameters of time and temperature were defined according to a 22 central composite rotatable design (CCRD, and the dependent variables were water holding capacity (WHC and instrumental texture aiming at obtaining high WHC values for the product to maintain the desired juiciness. The microbiological analysis required by legislation have indicated that the fish fillets and sous vide were within de standard. The values of total coliforms found in the samples (fillets and sous vide analyzed were below the critical level of 10² CFU/g. The counts of sulphite-reducing clostridia and psychrotrophic and mesophilic bacteria on plates in the samples were <1x10 CFU/g. In conclusion, temperature was the most important factor in the pasteurization process, significantly contributing to the quality of the final product. The mathematical models proposed were considered predictive for each response.

  18. A review on pipeline corrosion, in-line inspection (ILI), and corrosion growth rate models

    International Nuclear Information System (INIS)

    Vanaei, H.R.; Eslami, A.; Egbewande, A.

    2017-01-01

    Pipelines are the very important energy transmission systems. Over time, pipelines can corrode. While corrosion could be detected by in-line inspection (ILI) tools, corrosion growth rate prediction in pipelines is usually done through corrosion rate models. For pipeline integrity management and planning selecting the proper corrosion ILI tool and also corrosion growth rate model is important and can lead to significant savings and safer pipe operation. In this paper common forms of pipeline corrosion, state of the art ILI tools, and also corrosion growth rate models are reviewed. The common forms of pipeline corrosion introduced in this paper are Uniform/General Corrosion, Pitting Corrosion, Cavitation and Erosion Corrosion, Stray Current Corrosion, Micro-Bacterial Influenced Corrosion (MIC). The ILI corrosion detection tools assessed in this study are Magnetic Flux Leakage (MFL), Circumferential MFL, Tri-axial MFL, and Ultrasonic Wall Measurement (UT). The corrosion growth rate models considered in this study are single-value corrosion rate model, linear corrosion growth rate model, non-linear corrosion growth rate model, Monte-Carlo method, Markov model, TD-GEVD, TI-GEVD model, Gamma Process, and BMWD model. Strengths and limitations of ILI detection tools, and also corrosion predictive models with some practical examples are discussed. This paper could be useful for those whom are supporting pipeline integrity management and planning. - Highlights: • Different forms of pipeline corrosion are explained. • Common In-Line Inspection (ILI) tools and corrosion growth rate models are introduced. • Strength and limitations of corrosion growth rate models/ILI tools are discussed. • For pipeline integrity management programs using more than one corrosion growth rate model/ILI tool is suggested.

  19. Corrosion behavior of corrosion resistant alloys in stimulation acids

    Energy Technology Data Exchange (ETDEWEB)

    Cheldi, Tiziana [ENI E and P Division, 20097 San Donato Milanese Milano (Italy); Piccolo, Eugenio Lo; Scoppio, Lucrezia [Centro Sviluppo Materiali, via Castel Romano 100, 00128 Rome (Italy)

    2004-07-01

    In the oil and gas industry, selection of CRAs for downhole tubulars is generally based on resistance to corrosive species in the production environment containing CO{sub 2}, H{sub 2}S, chloride and in some case elemental sulphur. However, there are non-production environments to which these materials must also be resistant for either short term or prolonged duration; these environments include stimulation acids, brine and completion fluids. This paper reports the main results of a laboratory study performed to evaluate the corrosion and stress corrosion behaviour to the acidizing treatments of the most used CRAs for production tubing and casing. Laboratory tests were performed to simulate both 'active' and 'spent' acids operative phases, selecting various environmental conditions. The selected steel pipes were a low alloyed steel, martensitic, super-martensitic, duplex 22 Cr, superduplex 25 Cr and super-austenitic stainless steels (25 Cr 35 Ni). Results obtained in the 'active' acid environments over the temperature range of 100-140 deg. C, showed that the blend acids with HCl at high concentration and HCl + HF represented too much severe conditions, where preventing high general corrosion and heavy localised corrosion by inhibition package becomes very difficult, especially for duplex steel pipe, where, in some case, the specimens were completely dissolved into the solution. On the contrary, all steels pipes were successfully protected by inhibitor when organic acid solution (HCOOH + CH{sub 3}COOH) were used. Furthermore, different effectiveness on corrosion protection was showed by the tested inhibitors packages: e.g. in the 90% HCl at 12% + 10 CH{sub 3}COOH acid blend. In 'spent' acid environments, all steel pipes showed to be less susceptible to the localised and general corrosion attack. Moreover, no Sulphide Stress Corrosion Cracking (SSC) was observed. Only one super-austenitic stainless steel U-bend specimen showed

  20. Corrosion control in nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    Steele, D.F.

    1986-01-01

    This article looks in detail at tribology-related hazards of corrosion in irradiated fuel reprocessing plants and tries to identify and minimize problems which could contribute to disaster. First, the corrosion process is explained. Then the corrosion aspects at each of four stages in reprocessing are examined, with particular reference to oxide fuel reprocessing. The four stages are fuel receipt and storage, fuel breakdown and dissolution, solvent extraction and product concentration and waste management. Results from laboratory and plant corrosion trails are used at the plant design stage to prevent corrosion problems arising. Operational procedures which minimize corrosion if it cannot be prevented at the design stage, are used. (UK)

  1. A Theoretical Model for Metal Corrosion Degradation

    Directory of Open Access Journals (Sweden)

    David V. Svintradze

    2010-01-01

    Full Text Available Many aluminum and stainless steel alloys contain thin oxide layers on the metal surface which greatly reduce the corrosion rate. Pitting corrosion, a result of localized breakdown of such films, results in accelerated dissolution of the underlying metal through pits. Many researchers have studied pitting corrosion for several decades and the exact governing equation for corrosion pit degradation has not been obtained. In this study, the governing equation for corrosion degradation due to pitting corrosion behavior was derived from solid-state physics and some solutions and simulations are presented and discussed.

  2. General Corrosion and Localized Corrosion of the Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua

    2004-09-16

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847]).

  3. General Corrosion and Localized Corrosion of the Drip Shield

    International Nuclear Information System (INIS)

    F. Hua

    2004-01-01

    The repository design includes a drip shield (BSC 2004 [DIRS 168489]) that provides protection for the waste package both as a barrier to seepage water contact and a physical barrier to potential rockfall. The purpose of the process-level models developed in this report is to model dry oxidation, general corrosion, and localized corrosion of the drip shield plate material, which is made of Ti Grade 7. This document is prepared according to ''Technical Work Plan For: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The models developed in this report are used by the waste package degradation analyses for TSPA-LA and serve as a basis to determine the performance of the drip shield. The drip shield may suffer from other forms of failure such as the hydrogen induced cracking (HIC) or stress corrosion cracking (SCC), or both. Stress corrosion cracking of the drip shield material is discussed in ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]). Hydrogen induced cracking of the drip shield material is discussed in ''Hydrogen Induced Cracking of Drip Shield'' (BSC 2004 [DIRS 169847])

  4. Concrete cover cracking with reinforcement corrosion of RC beam during chloride-induced corrosion process

    International Nuclear Information System (INIS)

    Zhang Ruijin; Castel, Arnaud; Francois, Raoul

    2010-01-01

    This paper deals with the evolution of the corrosion pattern based on two beams corroded by 14 years (beam B1CL1) and 23 years (beam B2CL1) of conservation in a chloride environment. The experimental results indicate that, at the cracking initiation stage and the first stage of cracking propagation, localized corrosion due to chloride ingress is the predominant corrosion pattern and pitting corrosion is the main factor that influences the cracking process. As corrosion cracking increases, general corrosion develops rapidly and gradually becomes predominant in the second stage of cracking propagation. A comparison between existing models and experimental results illustrates that, although Vidal et al.'s model can better predict the reinforcement corrosion of beam B1CL1 under localized corrosion, it cannot predict the corrosion of beam B2CL1 under general corrosion. Also, Rodriguez's model, derived from the general corrosion due to electrically accelerated corrosion experiments, cannot match natural chloride corrosion irrespective of whether corrosion is localized or general. Thus, for natural general corrosion in the second stage of cracking propagation, a new model based on the parameter of average steel cross-section loss is put forward to predict steel corrosion from corrosion cracking.

  5. PLANTS AS A SOURCE OF GREEN CORROSION INHIBITORS ...

    African Journals Online (AJOL)

    Mgina

    Acacia senegal) exhibit good inhibition characteristics to corrosion on mild steel under fresh water medium and the ... as corrosion inhibitors for metals in various corrosive media ..... alloy corrosion in chloride solution", J. Appl. Electrochem.

  6. Influence of Citric Acid on the Pink Color and Characteristics of Sous Vide Processed Chicken Breasts During Chill Storage

    Science.gov (United States)

    Lim, Ki-Won

    2015-01-01

    Chicken breast dipped with citric acid (CA) was treated by sous vide processing and stored in a refrigerated state for 0, 3, 6, 9, and 14 d. A non-dipped control group (CON) and three groups dipped in different concentrations of citric acid concentration were analyzed (0.5%, 0.5CIT; 2.0%, 2CIT and 5.0%, 5CIT; w/v). Cooking yield and moisture content increased due to the citric acid. While the redness of the juice and meat in all groups showed significant increase during storage, the redness of the citric acid groups was reduced compared to the control group (pacid reactive substances (TBARS) were generally lower in the citric acid-treated samples than in untreated ones, indicating extended shelf life of the cooked chicken breast dipped in citric acid solution. The shear force of the 2CIT and 5CIT groups was significantly lower (pcitric acid concentrations. PMID:26761885

  7. Effect of different temperature-time combinations on lipid and protein oxidation of sous-vide cooked lamb loins.

    Science.gov (United States)

    Roldan, Mar; Antequera, Teresa; Armenteros, Monica; Ruiz, Jorge

    2014-04-15

    Forty-five lamb loins were subjected to sous-vide cooking at different combinations of temperature (60, 70 and 80 °C) and time (6, 12 and 24 h) to assess the effect on the oxidative stability of lipids and proteins. Heating induced both lipid and protein oxidation in lamb loins. Higher cooking temperature-time combinations increased conjugated dienes and decreased thiobarbituric reactive substances (TBARS) values and hexanal. Total protein carbonyls increased throughout time at all cooking temperatures considered, while α-aminoadipic (AAS) and γ-glutamic semialdehydes (GGS) increased when cooking at 60 °C but not at 80 °C. Links between the decrease in secondary compounds from lipid oxidation due to cooking at higher temperatures and for longer times with the increased levels of 3-methylbutanal and greater differences between total protein carbonyls and AAS plus GGS were hypothesised. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Les images en géographie sous l’angledes humanités numériques

    Directory of Open Access Journals (Sweden)

    Gaëlle Hallair

    2009-04-01

    Full Text Available L’article présente une méthodologie pour conserver, stocker, inventorier, archiver, numériser, indexer, valoriser et diffuser des archives géographiques sous l’angle des Digital humanities. L’article applique cette méthodologie aux images en géographie avant de présenter un projet de plate-forme documentaire concernant les plaques de verres du fonds Emmanuel de Martonne hébergées actuellement par l’UMR CNRS 8586 PRODIG.This article points out the methodology of Digital humanities to preserve, to stock, to make an inventory, to digitize, to index, to enhance the value und to spread geographical archives. It applies this methodology to geographical visual documents and presents a database project about photographic plates of the Emmanuel de Martonne’s collection localised in the research center PRODIG (UMR CNRS 8586.

  9. Lille, place financière intermédiaire sous la Révolution et l’Empire

    OpenAIRE

    De Oliveira, Matthieu

    2011-01-01

    Dernière grande place négociante et financière avant la frontière septentrionale, Lille joue pleinement son rôle d’intermédiaire entre les marchés parisiens au Sud et belgo-hollandais au Nord sous la Révolution et l’Empire. La déclaration de guerre en 1792 puis la départementalisation des territoires conquis ne font que renforcer la position nodale des acteurs économiques et financiers de la place. Au premier rang d’entre eux, François Briansiaux mobilise efficacement son important réseau de ...

  10. Contraint's theory and relativistic dynamics

    International Nuclear Information System (INIS)

    Longhi, G.; Lusanna, L.

    1987-01-01

    The purpose of this Workshop was to examine the current situation of relativistic dynamics. In particular, Dirac-Bergmann's theory of constraints, which lies at the heart of gauge theories, general relativity, relativistic mechanics and string theories, was chosen as the unifying theoretical framework best suited to investigate such a field. The papers discussed were on general relativity; relativistic mechanics; particle physics and mathematical physics. Also discussed were the problems of classical and quantum level, namely the identification of the classical observables of constrained systems, the equivalence of the nonequivalence of the various ways to quantize such systems; the problem of the anomalies; the best geometrical approach to the theory of constraints; the possibility of unifying all the treatments of relativistic mechanics. This book compiles the papers presented at proceedings of relativistic dynamics and constraints theory

  11. Orientation de la contrainte tectonique pans l'Europe de l'Ouest à partir des ovalisations de trous de forages Orientation of Tectonic Stress in Western Europe from Borehole Breakouts

    Directory of Open Access Journals (Sweden)

    Janot P.

    2006-11-01

    Full Text Available La recherche de l'orientation de la contrainte majeure horizontale actuelle à partir de l'ovalisation des trous de forages (Synthèse exposée dans le numéro mai-juin 1988 de la Revue de l'institut Français du Pétrole, permet de déceler la direction des systèmes de fractures ouvertes en condition de fond. L'ovalisation des trous de forages, détectée par la Pendagemétrie 4 patins en relation avec l'écaillage d'un secteur des parois du sondage, conduit, après tri de l'information, à la connaissance de la direction de la contrainte majeure horizontale actuelle, localement, au voisinage du puits. L'établissement d'une carte de ces orientations pour l'Europe de l'Ouest, de l'Italie à la Norvège, montre une grande cohérence dans les directions obtenues par cette méthode. Cette cohérence s'explique par l'orientation générale des forces nées de la collision actuelle des plaques Afrique (à laquelle appartient l'Italie et Europe (Aquitaine, Bassin Parisien, mer du Nord. Cependant, cette carte met en évidence un certain nombre d'anomalies (Fossé Rhénan, ouest du bassin de Paris, Grabens de mer du Nord par rapport à l'orientation générale de la contrainte actuelle. Ces anomalies (déviation plus ou moins importante de la contrainte s'expliquent, du fait de leur localisation, par l'influence d'accidents tectoniques profonds liés aux anciennes directions de phases orogéniques : calédonienne hercynienne et laramienne. La recherche de ces anomalies pourrait être un moyen de détection de la proximité de ces grands traits structuraux majeurs du socle. Research on the orientation of current major horizontal stress from borehole breakouts (cf. synthesis report in the May-June 1988 issue of the Revue de l'Institut Français du Pétrole reveals the direction of open fracture systems under downhole conditions. Borehole breakout, detected by 4-pad dipmetering in relation to the scaling of one sector of borehole walls leads, after the

  12. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  13. A new corrosion monitoring technique

    International Nuclear Information System (INIS)

    Brown, Gerald K.

    2000-01-01

    Internal Corrosion Monitoring has relied upon 5 basic techniques. Little improvement in performance has been achieved in any of these. Many newer internal corrosion monitoring techniques have proved of little value in the field although some have instances of success in the laboratory. Industry has many high value hydrocarbon applications requiring corrosion rate monitoring for real-time problem solving and control. The high value of assets and the cost of asset replacement makes it necessary to practice cost effective process and corrosion control with sensitivity beyond the 5 basic techniques. This new metal loss technology offers this sensitivity. Traditional metal loss technology today provides either high sensitivity with short life, or conversely, long life but with substantially reduced sensitivity. The new metal loss technology offers an improved working life of sensors without significantly compromising performance. The paper discusses the limitations of existing on-line technologies and describes the performance of a new technology. This new metal loss technology was introduced at NACE Corrosion 99'. Since that time several field projects have been completed or are ongoing. This paper will discuss the new metal loss technology and report on some of the data that has been obtained.(author)

  14. Corrosion effects on friction factors

    International Nuclear Information System (INIS)

    Magleby, H.L.; Shaffer, S.J.

    1996-01-01

    This paper presents the results of NRC-sponsored material specimen tests that were performed to determine if corrosion increases the friction factors of sliding surfaces of motor-operated gate valves, which could require higher forces to close and open safety-related valves when subjected to their design basis differential pressures. Friction tests were performed with uncorroded specimens and specimens subjected to accelerated corrosion. Preliminary tests at ambient conditions showed that corrosion increased the friction factors, indicating the need for additional tests duplicating valve operating parameters at hot conditions. The additional tests showed friction factors of corroded specimens were 0.1 to 0.2 higher than for uncorroded specimens, and that the friction factors of the corroded specimens were not very dependent on contact stress or corrosion film thickness. The measured values of friction factors for the three corrosion films tested (simulating three operating times) were in the range of 0.3 to 0.4. The friction factor for even the shortest simulated operating time was essentially the same as the others, indicating that the friction factors appear to reach a plateau and that the plateau is reached quickly

  15. Hanford transuranic storage corrosion review

    International Nuclear Information System (INIS)

    Nelson, J.L.; Divine, J.R.

    1980-12-01

    The rate of atmospheric corrosion of the transuranic (TRU) waste drums at the US Department of Energy's Hanford Project, near Richland, Washington, was evaluated by Pacific Northwest Laboratory (PNL). The rate of corrosion is principally contingent upon the effects of humidity, airborne pollutants, and temperature. Results of the study indicate that actual penetration of barrels due to atmospheric corrosion will probably not occur within the 20-year specified recovery period. Several other US burial sites were surveyed, and it appears that there is sufficient uncertainty in the available data to prevent a clearcut statement of the corrosion rate at a specific site. Laboratory and site tests are recommended before any definite conclusions can be made. The corrosion potential at the Hanford TRU waste site could be reduced by a combination of changes in drum materials (for example, using galvanized barrels instead of the currently used mild steel barrels), environmental exposure conditions (for example, covering the barrels in one of numerous possible ways), and storage conditions

  16. Notes on the measurement of stress by resistance gauges in the presence of a magnetic field; Note sur les mesures de contraintes par jauges a fil resistant en presence de champ magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Armand, G; Lapujoulade, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1961-07-01

    The technique of stress measurement by resistance gauges is well known. Although it is not yet perfect it possesses many advantages and shows great possibilities. In the presence of a magnetic field the measurement is perturbed by certain phenomena, and we have undertaken to calculate their order of magnitude with a view to establishing the error involved in the measurement. Our problem was to measure the stresses on the various parts of the magnet in the synchrotron Saturne. It is known that the induction passes from a value of about nil to 15000 gauss in 0.8 second, and returns to zero in the same time interval; this cycle recurs every 3.2 seconds. In order to isolate the effects the problem of measurements in a static field will be examined first, after which the results obtained will be extended to the case of dynamic fields. (author) [French] La technique de mesure de contraintes par jauges a fil resistant est bien connue. Elle presente de nombreux avantages, beaucoup de possibilites, bien que n'etant pas encore parfaite. En presence de champ magnetique, la mesure est perturbee par un certain nombre de phenomenes dont nous avons ete conduits a chiffrer l'ordre de grandeur afin de connaitre l'erreur commise lors de la mesure. Precisons qu'il s'agissait pour nous de mesurer les contraintes sur les differents organes de l'aimant du synchrotron Saturne. L'on sait que la valeur de l'induction au droit de l'entrefer passe d'une valeur sensiblement nulle a 15000 gauss en 0,8 secondes, pour revenir ensuite a zero pendant un temps egal au precedent; le cycle ci-dessus se reproduit toutes les 3,2 secondes. Afin de separer les effets, nous examinerons d'abord le probleme des mesures en champ statique puis nous etendrons les resultats obtenus au cas des champs dynamiques. (auteur)

  17. Behaviour of uranium under irradiation; Comportement de l'uranium sous irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Adda, Y; Mustelier, J P; Quere, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    phase alloys (U Nb, U Mo) the size and distribution of the bubbles are greatly influenced by the existence of a polygonization lattice, formed before irradiation, inside the grains. During high temperature annealings the bubbles situated on the polygonization lattice grow much faster than those which are distributed inside the crystal. In the case of uranium the bubbles are either distributed at random, or grouped in flat accumulations which can give rise to transgranular cracks, according to the state of the metal and the irradiation temperature. At high temperature an intergranular de-cohesion is also observed. (authors) [French] On expose les principaux resultats obtenus dans l'etude de la formation des defauts introduits dans l'uranium par la fission a basse temperature. Par irradiation a 20 K on a pu evaluer le nombre de paires de Frenkel produites par une fission. L'analyse des courbes de variation de resistivite electrique a permis de preciser l'etendue des pointes de deplacement (deplacement Spike) et le mecanisme de la creation des defauts dus a la fission. Des irradiations a 77 K ont apporte des precisions supplementaires et indiquent un comportement different de l'uranium recristallise et ecroui. On a etudie la diffusion des gaz rares a partir d'alliages metal-gaz rare obtenus par decharge electrique et d'echantillons d'uranium irradie. Le degagement des gaz rares sous vide n'est controle par un processus de diffusion simple que dans le cas ou la teneur en gaz rare est tres faible (U tres faiblement irradie). Par contre quand la teneur en gaz rare est plus forte (echantillons prepares par decharge electrique) le degagement du gaz se produit par formation, croissance et coalescence de bulles; le coefficient de diffusion apparent est alors tres different du coefficient vrai et ne peut etre utilise dans les calculs de gonflement. Dans le cas d'un processus de diffusion simple on a etudie les differents facteurs qui regissent le phenomene. On a montre en

  18. Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

    Science.gov (United States)

    Huang, B. S.; Yin, W. F.; Sang, D. H.; Jiang, Z. Y.

    2012-10-01

    The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 °C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr5S8 phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

  19. Quantitative measures of corrosion and prevention: application to corrosion in agriculture

    NARCIS (Netherlands)

    Schouten, J.C.; Gellings, P.J.

    1987-01-01

    The corrosion protection factor (c.p.f.) and the corrosion condition (c.c.) are simple instruments for the study and evaluation of the contribution and efficiency of several methods of corrosion prevention and control. The application of c.p.f. and c.c. to corrosion and prevention in agriculture in

  20. Some observations about the Incoloy 800 corrosion

    International Nuclear Information System (INIS)

    Baptista, W.; Sathler, L.; Mattos, O.R.

    1985-01-01

    The chemical and electrochemical characteristics of synthetic solutions similar to those inside the occluded cell corrosion - OCC (pitting, cracks from stress corrosion) of incoloy 800, 25 0 C are studied. (E.G.) [pt

  1. Rail base corrosion and cracking prevention

    Science.gov (United States)

    2014-07-01

    Rail base corrosion combined with fatigue or damage can significantly reduce rail life. Studies were done to examine the relative contribution of damage, corrosion, and fatigue on rail life. The combined effects can be separated into constituent fact...

  2. Corrosion studies on PREPP waste form

    International Nuclear Information System (INIS)

    Welch, J.M.; Neilson, R.M. Jr.

    1984-05-01

    Deformation or Failure Test and Accelerated Corrosion Test procedures were conducted to investigate the effect of formulation variables on the corrosion of oversize waste in Process Experimental Pilot Plant (PREPP) concrete waste forms. The Deformation or Failure Test did not indicate substantial waste form swelling from corrosion. The presence or absence of corrosion inhibitor was the most significant factor relative to measured half-cell potentials identified in the Accelerated Corrosion Test. However, corrosion inhibitor was determined to be only marginally beneficial. While this study produced no evidence that corrosion is of sufficient magnitude to produce serious degradation of PREPP waste forms, the need for corrosion rate testing is suggested. 11 references, 4 figures, 8 tables

  3. Corrosion problems in light water nuclear reactors

    International Nuclear Information System (INIS)

    Berry, W.E.

    1984-01-01

    The corrosion problems encountered during the author's career are reviewed. Attention is given to the development of Zircaloys and attendant factors that affect corrosion; the caustic and chloride stress corrosion cracking (SCC) of austenitic stainless steel steam generator tubing; the qualification of Inconel Alloy 600 for steam generator tubing and the subsequent corrosion problem of secondary side wastage, caustic SCC, pitting, intergranular attack, denting, and primary side SCC; and SCC in weld and furnace sensitized stainless steel piping and internals in boiling water reactor primary coolants. Also mentioned are corrosion of metallic uranium alloy fuels; corrosion of aluminum and niobium candidate fuel element claddings; crevice corrosion and seizing of stainless steel journal-sleeve combinations; SCC of precipitation hardened and martensitic stainless steels; low temperature SCC of welded austenitic stainless steels by chloride, fluoride, and sulfur oxy-anions; and corrosion problems experienced by condensers

  4. Accelerated Test Method for Corrosion Protective Coatings

    Data.gov (United States)

    National Aeronautics and Space Administration — This project seeks to develop a new accelerated corrosion test method that predicts the long-term corrosion protection performance of spaceport structure coatings as...

  5. Microencapsulation of Corrosion Indicators for Smart Coatings

    Science.gov (United States)

    Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott T.; Calle, Luz M.; Hanna,Joshua S.; Rawlins, James W.

    2011-01-01

    A multifunctional smart coating for the autonomous detection, indication, and control of corrosion is been developed based on microencapsulation technology. This paper summarizes the development, optimization, and testing of microcapsules specifically designed for early detection and indication of corrosion when incorporated into a smart coating. Results from experiments designed to test the ability of the microcapsules to detect and indicate corrosion, when blended into several paint systems, show that these experimental coatings generate a color change, indicative of spot specific corrosion events, that can be observed with the naked eye within hours rather than the hundreds of hours or months typical of the standard accelerated corrosion test protocols.. Key words: smart coating, corrosion detection, microencapsulation, microcapsule, pH-sensitive microcapsule, corrosion indicator, corrosion sensing paint

  6. Corrosion monitoring using FSM technology

    International Nuclear Information System (INIS)

    Strommen, R.; Horn, H.; Gartland, P.O.; Wold, K.; Haroun, M.

    1995-01-01

    FSM is a non-intrusive monitoring technique based on a patented principle, developed for the purpose of detection and monitoring of both general and localized corrosion, erosion, and cracking in steel and metal structures, piping systems, and vessels. Since 1991, FSM has been used for a wide range of applications, including for buried and open pipelines, process piping offshore, subsea pipelines and flowlines, applications in the nuclear power industry, and in materials, research in general. This paper describes typical applications of the FSM technology, and presents operational experience from some of the land-based and subsea installations. The paper also describes recent enhancements in the FSM technology and in the analysis of FSM readings, allowing for monitoring and detailed quantification of pitting and mesa corrosion, and of corrosion in welds

  7. Corrosion of Al-7075 by uranium hexafluoride

    International Nuclear Information System (INIS)

    1989-01-01

    The results of the Al-7075 corrosion by uranium hexafluoride are presented in this work. The kinetic study shows that corrosion process occurs by two temperature dependent mechanism and that the alloy can be safely used up to 140 0 C. The corrosion film is formed by uranium oxifluoride with variable composition in depth. Two alternative corrosion models are proposed in order to explain the experimental results, as well as the tests taht will be carried out to confirm one of them [pt

  8. Erosion–corrosion and corrosion properties of DLC coated low temperature Erosion–corrosion and corrosion properties of DLC coated low temperature

    DEFF Research Database (Denmark)

    Jellesen, Morten Stendahl; Christiansen, Thomas; Hilbert, Lisbeth Rischel

    2009-01-01

    of AISI 316 as substrate for DLC coatings are investigated. Corrosion and erosion–corrosion measurements were carried out on low temperature nitrided stainless steel AISI 316 and on low temperature nitrided stainless steel AISI 316 with a top layer of DLC. The combination of DLC and low temperature...... nitriding dramatically reduces the amount of erosion–corrosion of stainless steel under impingement of particles in a corrosive medium....

  9. Microbiologically Influenced Corrosion: Causative Organisms and Mechanisms

    Science.gov (United States)

    2012-01-31

    enviromental composition as a potential method for reversing microbiologically influenced corrosion, Corrosion (NAC’E) International. Houston. Texas...International fellow and associate editor for Biofouling, The Journal of Bioadhesion and Biofilm Research. J. Lee is a Materials and Corrosion Engineer

  10. Corrosion and chemical resistant masonry materials handbook

    National Research Council Canada - National Science Library

    Sheppard, Walter Lee

    1986-01-01

    ... and other equipment. But few other than chemists and chemical engineers identify "corrosion" as chemical degradation or destruction of a material, and therefore, something that can happen to nonmetals (concrete, plastics, brick, timber, etc.) as well as to nletals. The National Association of Corrosion Engineers so defined "corrosion" over thirty years ago but this f...

  11. Corrosion of reinforcement induced by environment containing ...

    Indian Academy of Sciences (India)

    Unknown

    carbonation and chlorides causing corrosion of steel reinforcement. ... interesting and important when the evaluation of the service life of the ... preferably in the areas of industrial and transport activities. ... For controlling the embedded corrosion sensors, elec- .... danger of corrosion of reinforcement seems to be more.

  12. Solutions of corrosion Problems in advanced Technologies

    DEFF Research Database (Denmark)

    Montgomery, Melanie; Karlsson, Asger

    1999-01-01

    Austenitic and ferritic steels were exposed in the superheater area of a straw-fired CHP plant. The specimens were exposed for 1400 hours at 450-600°C. The rate of corrosion was assessed based on unattacked metal remaining. The corrosion products and course of corrosion for the various steel types...

  13. Corrosion resistance of zirconium in nitric acid

    International Nuclear Information System (INIS)

    Kajimura, H.; Morikawa, H.; Nagano, H.

    1987-01-01

    Slow strain rate tests are effected on zirconium in boiling nitric acid to study the influence of nitric acid concentration, of oxidizing ions (Cr and Ce) and of electric potential. Corrosion resistance is excellent and stress corrosion cracking occurs only for severe conditions: 350 mV over electric potential for corrosion with nitric acid concentration of 40 % [fr

  14. Tests on dynamic corrosion by water. Influence of the passage of a heat flux on the corrosion kinetics. pH measurement in water at high temperature; Essais de corrosion dynamique par l'eau. Influence du passage d'un flux thermique sur la cinetique de corrosion. Mesure du pH dans l'eau a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H.; Grall, L.; Hure, J.; Saint-James, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Berthod [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France); Le peintre [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France)

    1958-07-01

    'eau sous pression a une temperature voisine de 280 deg. C, la vitesse de circulation atteint 6 m/s. On etudie, du point de vue de la corrosion, les resultats obtenus, sur des gaines en aluminium, en attachant beaucoup d'attention aux phenomenes de cavitation susceptibles de causer de graves degats dans certaines circonstances particulieres. Apres avoir mis au point un dispositif d'electrode en verre pouvant supporter des pressions elevees les auteurs ont fait des recherches concernant les materiaux susceptibles de fonctionner comme electrode d'hydrogene et capables de resister convenablement a la corrosion par l'eau a 200 deg. C. Diverses possibilites ont ete examinees: electrodes de verres speciaux, de quartz, metallique, a membrane etc. On donne les resultats des differents essais et les limites pratiques d'utilisation. (auteur)

  15. Tests on dynamic corrosion by water. Influence of the passage of a heat flux on the corrosion kinetics. pH measurement in water at high temperature; Essais de corrosion dynamique par l'eau. Influence du passage d'un flux thermique sur la cinetique de corrosion. Mesure du pH dans l'eau a haute temperature

    Energy Technology Data Exchange (ETDEWEB)

    Coriou, H; Grall, L; Hure, J; Saint-James, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Berthod, [Societe Grenobloise d' Etudes et d' Applications Hydrauliques, 38 (France); peintre, Le [Centre National de la Recherche Scientifique (CNRS), 38 - Grenoble (France)

    1958-07-01

    The passage of a heat flux through the surface of a metal placed in a corrosive medium influences the rate of corrosion, these being higher than under adiabatic conditions. The apparatus developed for corrosion tests is described, it is possible to obtain with this equipment: 1) Heat fluxes greater than 200 W/cm{sup 2}, across aluminium canning, which is cooled by water (temperature 50 deg. C), circulating with flow rates of the order of 5 to 6 m/s. 2) Heat fluxes which can go up to 150 W/cm{sup 2}, across canning of zircaloy or stainless steel. The cooling fluid is pressurized water at a temperature around 280 deg. C, the flow-rate of circulation reaching 6 m/s. The results obtained on aluminium canning are studied from the viewpoint of corrosion, paying particular attention to cavitation phenomena which can cause serious damage in certain special circumstances. After developing a glass electrode system capable of supporting high pressures, the authors have investigated materials capable of functioning as a hydrogen electrode and of resisting satisfactorily corrosion by water at 200 deg. C. Various possibilities have been examined: electrodes of special glasses, quartz, metals, with a membrane etc... The results of the various tests and the practical limits of utilisation are given. (author)Fren. [French] Le passage d'un flux thermique a travers la surface d'un metal place dans un milieu corrosif influence les vitesses de corrosion, celles-ci etant plus elevees que dans des conditions adiabatiques. On decrit les appareils mis au point, pour essais de corrosion. Ils permettent d'obtenir: 1) A travers des gaine aluminium des flux thermiques depassant 200 W /cm{sup 2}. Les gaines sont refroidies par l'eau (temperature 50 deg. C), circulant a des vitesses de l'ordre de 5 a 6 m/s. 2) A travers des gaines en zircaloy ou acier inoxydable des flux thermiques pouvant s'elever a 150 W/cm{sup 2}. Le fluide de refroidissement est de l'eau sous pression a une temperature

  16. Morphological kinetics and localized corrosion

    International Nuclear Information System (INIS)

    Santarini, G.

    1992-01-01

    A phenomenological modeling is proposed for physicochemical systems that evolve by initiation and growth of well distinct defects. It consists in a mathematical treatment of data on the evolution of defect distribution, which leads to the knowledge of evolution parameters ultimately usable for behaviour predictions. A method is given for calculating a validity parameter which quantifies the pertinence of the choice for analytical representations. An example of application to localized corrosion is given with the intergranular stress corrosion cracking of Alloy 600 in high temperature water. (Author). 6 refs

  17. High temperature corrosion in gasifiers

    Directory of Open Access Journals (Sweden)

    Bakker Wate

    2004-01-01

    Full Text Available Several commercial scale coal gasification combined cycle power plants have been built and successfully operated during the last 5-10 years. Supporting research on materials of construction has been carried out for the last 20 years by EPRI and others. Emphasis was on metallic alloys for heat exchangers and other components in contact with hot corrosive gases at high temperatures. In this paper major high temperature corrosion mechanisms, materials performance in presently operating gasifiers and future research needs will be discussed.

  18. Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

    Energy Technology Data Exchange (ETDEWEB)

    Huang, B.S., E-mail: yinwenfeng2010@163.com [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Yin, W.F. [College of Mechatronic Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Sang, D.H. [Sheng Li Construction Group International Engineering Department, Shandong, Dongying, 257000 (China); Jiang, Z.Y. [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer The corrosion of a carbon-manganese steel and a stainless steel in sulfur and/or naphthenic acid media was investigated. Black-Right-Pointing-Pointer The corrosion rate of the carbon-manganese steel increased with the increase of the acid value and sulfur content. Black-Right-Pointing-Pointer The critical values of the concentration of sulfur and acid for corrosion rate of the stainless steel were ascertained respectively. Black-Right-Pointing-Pointer The stainless steel is superior to the carbon-manganese steel in corrosion resistance because of the presence of stable Cr{sub 5}S{sub 8} phases. - Abstract: The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 Degree-Sign C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr{sub 5}S{sub 8} phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

  19. Corrosion and corrosion protection of support structures for offshore wind energy devices (OWEA)

    Energy Technology Data Exchange (ETDEWEB)

    Momber, A. [Muehlhan AG, Schlinckstrasse 3, D-21107 Hamburg (Germany)

    2011-05-15

    The paper provides a review about the corrosion and corrosion protection of offshore wind energy devices (OWEA). Firstly, special features resulting from location and operation of OWEA are being discussed. Secondly, types of corrosion and corrosion phenomena are summarized in a systematic way. Finally, practical solutions to the corrosion protection of OWEA, including steel allowances, cathodic protection and coatings and linings, are discussed. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. Utilisation des sous-produits agroalimentaires dans l’alimentation des poissons d’élevage en Côte d’Ivoire

    Directory of Open Access Journals (Sweden)

    Kimou Nestor B.

    2016-03-01

    Full Text Available Cette étude évalue l’impact de l’utilisation des sous-produits agroalimentaires dans l’alimentation des poissons d’élevage en Côte d’Ivoire. Une enquête a été réalisée en 2013 dans quinze principales zones piscicoles sur les caractéristiques technico-économiques des fermes, le profil socio-économique des promoteurs et les pratiques aquacoles, particulièrement l’alimentation des poissons. Les résultats révèlent que 71 % des pisciculteurs enquêtés utilisent des sous-produits agricoles durant au moins un stade de production. Parmi eux, 53 % utilisent exclusivement des sous-produits. Le son de riz (52 % et le mélange de sons de riz et de maïs (28 % sont les plus utilisés. Les prix moyens de ces sous-produits varient entre 20 et 105 FCFA/kg. Oreochromis niloticus et Heterotis niloticus sont les principales espèces élevées en polyculture sur les fermes. Les sous-produits sont utilisés en système semi-intensif, extensif et en rizipisciculture, en majorité en zone rurale. Les pisciculteurs sont pour la plupart des agriculteurs, âgés de plus de 40 ans. Les taux d’utilisation des sous-produits sont plus élevés dans les régions de l’Ouest, du Centre-Ouest et du Sud-Ouest de la Côte d’Ivoire, par rapport à celles du Sud et de l’Est. Les rendements des fermes sont relativement faibles (544 à 2445 kg/ha/an, avec des gains moyens quotidiens de 0,87 et 9,97 g/j pour le tilapia et l’heterotis respectivement. L’analyse des stratégies des acteurs suggère la nécessité de définir des mécanismes d’accompagnement et de financement de la pisciculture, afin que ces acteurs puissent améliorer les formulations alimentaires à partir des matières premières locales et accessibles.

  1. 219-S CORROSION STUDY

    International Nuclear Information System (INIS)

    DIVINE, J.R.; PARSONS, G.L.

    2008-01-01

    A minor leak was detected in a drain line for Hood 2B located in the 222-S Laboratory. The line transfers radioactive waste, spent analytical standards, and chemicals used in various analytical procedures. Details are in the report provided by David Comstock, 2B NDE June 2008, work package LAB-WO-07-2012. Including the noted leak, the 222-S Laboratory has experienced two drain line leaks in approximately the last two years of operation. As a consequence, CH2M HILL Hanford Group, Inc. (CH2M HILL) requested the support of ChemMet, Ltd., PC (ChemMet) at the Hanford Site 222-S Laboratory. The corrosion expertise from ChemMet was required prior to preparation of a compatibility assessment for the 222-S Laboratory waste transfer system to assure the expected life of the piping system is extended as much as practicable. The system includes piping within the 222-S Laboratory and the 219-S Waste Storage and Transfer Facility and Operations Process. The ChemMet support was required for an assessment by 222-S staff to analyze what improvements to operational activities may be implemented to extend the tank/piping system life. This assessment will include a summary of the various material types, age, and locations throughout the facility. The assessment will also include a discussion of materials that are safe for drain line disposal on a regular basis, materials that are safe for disposal on a case-by-case basis including specific additional requirements such as flushing, neutralization to a specific pH, and materials prohibited from disposal. The assessment shall include adequate information for 222-S Laboratory personnel to make informed decisions in the future disposal of specific material types by discussing types of compatibility of system materials and potential wastes. The assessment is expected to contain some listing of acceptable waste materials but is not anticipated to be a complete or comprehensive list. Finally the assessment will encompass a brief discussion of

  2. EUROCORR 2007 - The European corrosion congress - Progress by corrosion control. Book of Abstracts

    International Nuclear Information System (INIS)

    2007-01-01

    This book of abstracts contains lectures, workshops and posters which were held on the European Corrosion Congress 2007 in Freiburg (Germany). The main topics of the sessions and posters are: 1. Corrosion and scale inhibition; 2. Corrosion by hot gases and combustion products; 3. Nuclear corrosion; 4. Environment sensitive fracture; 5. Surface Science; 6. Physico-chemical methods of corrosion testing; 7. Marine corrosion; 8. Microbial corrosion; 9. Corrosion of steel in concrete; 10. Corrosion in oil and gas production; 11. Coatings; 12. Corrosion in the refinery industry; 13. Cathodic protection; 14. Automotive Corrosion; 15. Corrosion of polymer materials. The main topics of the workshops are: 1. High temperature corrosion in the chemical, refinery and petrochemical industries; 2. Bio-Tribocorrosion; 3. Stress corrosion cracking in nuclear power plants; 4. Corrosion monitoring in nuclear systems; 5. Cathodic protection for marine and offshore environments; 6. Self-healing properties of new surface treatments; 7. Bio-Tribocorrosion - Cost 533/Eureka-ENIWEP-Meeting; 8. Drinking water systems; 9. Heat exchangers for seawater cooling

  3. General Corrosion and Localized Corrosion of Waste Package Outer Barrier

    Energy Technology Data Exchange (ETDEWEB)

    Farmer, J.C.; McCright, R.D.

    2000-01-28

    Alloy 22 is an extremely Corrosion Resistant Material, with a very stable passive film. Based upon exposures in the LTCTF, the GC rates of Alloy 22 are typically below the level of detection, with four outliers having reported rates up to 0.75 #mu#m per year. In any event, over the 10,000 year life of the repository, GC of the Alloy 22 (assumed to be 2 cm thick) should not be life limiting. Because measured corrosion potentials are far below threshold potentials, localized breakdown of the passive film is unlikely under plausible conditions, even in SSW at 120 deg C. The pH in ambient-temperature crevices formed from Alloy 22 have been determined experimentally, with only modest lowering of the crevice pH observed under plausible conditions. Extreme lowering of the crevice pH was only observed under situations where the applied potential at the crevice mouth was sufficient to result in catastrophic breakdown of the passive film above the threshold potential in non-buffered conditions not characteristic of the Yucca Mountain environment. In cases where naturally ocurring buffers are present in the crevice solution, little or no lowering of the pH was observed, even with significant applied potential. With exposures of twelve months, no evidence of crevice corrosion has been observed in SDW, SCW and SAW at temperatures up to 90 deg C. An abstracted model has been presented, with parameters determined experimentally, that should enable performance assessment to account for the general and localized corrosion of this material. A feature of this model is the use of the materials specification to limit the range of corrosion and threshold potentials, thereby making sure that substandard materials prone to localized attack are avoided. Model validation will be covered in part by a companion SMR on abstraction of this model.

  4. Liquid metal corrosion considerations in alloy development

    International Nuclear Information System (INIS)

    Tortorelli, P.F.; DeVan, J.H.

    1984-01-01

    Liquid metal corrosion can be an important consideration in developing alloys for fusion and fast breeder reactors and other applications. Because of the many different forms of liquid metal corrosion (dissolution, alloying, carbon transfer, etc.), alloy optimization based on corrosion resistance depends on a number of factors such as the application temperatures, the particular liquid metal, and the level and nature of impurities in the liquid and solid metals. The present paper reviews the various forms of corrosion by lithium, lead, and sodium and indicates how such corrosion reactions can influence the alloy development process

  5. Corrosion measurement using flux gate magnetometer

    International Nuclear Information System (INIS)

    Rashdi Shah Ahmad; Chong Cheong Wei

    2001-01-01

    The ability of fluxgate magnetometer to detect and measure quantitatively the magnetic field generated by electrochemical corrosion is presented. In this study, each sample (iron plate) was exposed to a range of increasingly corrosive environment. During the exposure, we measured the magnetic field above the sample for specific duration of time. The result shows that there is a clear relationship between corrosivity of the environment and the change in magnitude of magnetic field that was generated by the corrosion reaction. Therefore, the measurement of magnetic field might be used to determine the corrosion rates. (Author)

  6. Nodular Corrosion Characteristics of Zirconium Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Gil; Jeong, Y. H.; Park, S. Y.; Lee, D. J

    2003-01-15

    This study was reported the effect of the nodular corrosion on the nuclear reactor environmental along with metallurgical influence, also suggested experimental scheme related to evaluate nodular corrosion characteristics of Zr-1 Nb alloy. Remedial strategies against the nodular corrosion should firstly develop plan to assess the effect of the water quality condition (Oxygen, Hydrogen) as well as the boiling on the nodular corrosion, secondarily establish plan to control heat treatment process to keep a good resistance on nodular corrosion in Zr-1Nb alloy as former western reactor did.

  7. Assessing Level and Effectiveness of Corrosion Education in the UAE

    Directory of Open Access Journals (Sweden)

    Hwee Ling Lim

    2012-01-01

    Full Text Available The consequences of corrosion can be minimized by an engineering workforce well trained in corrosion fundamentals and management. Since the United Arab Emirates incurs the second highest cost of corrosion after Saudi Arabia, this paper examined the quality of corrosion education in the UAE. Surveys with academia and industry respondents showed that dedicated corrosion courses and engineering courses that integrated corrosion into the curricula were available in UAE universities, but graduates had insufficient knowledge of corrosion engineering and superficial understanding of corrosion in real-life design contexts. The effectiveness of corrosion education is determined by both competence in corrosion knowledge/skills and availability of resources (faculty and research. Though most departments would not hire new corrosion-specialist faculty, department research efforts and industry partnerships in corrosion research were present. The paper concluded with recommendations for improving knowledge and skills of future engineers in corrosion and enhancing corrosion instruction to better meet industry needs.

  8. Erosion corrosion in wet steam

    International Nuclear Information System (INIS)

    Tavast, J.

    1988-03-01

    The effect of different remedies against erosion corrosion in wet steam has been studied in Barsebaeck 1. Accessible steam systems were inspected in 1984, 1985 and 1986. The effect of hydrogen peroxide injection of the transport of corrosion products in the condensate and feed water systems has also been followed through chemical analyses. The most important results of the project are: - Low alloy chromium steels with a chromium content of 1-2% have shown excellent resistance to erosion corrosion in wet steam. - A thermally sprayed coating has shown good resistance to erosion corrosion in wet steam. In a few areas with restricted accessibility minor attacks have been found. A thermally sprayed aluminium oxide coating has given poor results. - Large areas in the moisture separator/reheater and in steam extraction no. 3 have been passivated by injection of 20 ppb hydrogen peroxide to the high pressure steam. In other inspected systems no significant effect was found. Measurements of the wall thickness in steam extraction no. 3 showed a reduced rate of attack. - The injection of 20 ppb hydrogen peroxide has not resulted in any significant reduction of the iron level result is contrary to that of earlier tests. An increase to 40 ppb resulted in a slight decrease of the iron level. - None of the feared disadvantages with hydrogen peroxide injection has been observed. The chromium and cobalt levels did not increase during the injection. Neither did the lifetime of the precoat condensate filters decrease. (author)

  9. Corrosion of austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M C.M. [Instituto Nacional de Tecnologia, Rio de Janeiro (Brazil)

    1977-01-01

    Types of corrosion observed in a heat exchanger pipe and on a support of still of molasses fermented wort, both in austenitic stainless steel, are focused. Not only are the causes which might have had any kind of influence on them examined, but also the measures adopted in order to avoid and lessen its occurence.

  10. Automated methods of corrosion measurement

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov; Bech-Nielsen, Gregers; Reeve, John Ch

    1997-01-01

    to revise assumptions regarding the basis of the method, which sometimes leads to the discovery of as-yet unnoticed phenomena. The present selection of automated methods for corrosion measurements is not motivated simply by the fact that a certain measurement can be performed automatically. Automation...... is applied to nearly all types of measurements today....

  11. Stress corrosion in gaseous environment

    International Nuclear Information System (INIS)

    Miannay, Dominique.

    1980-06-01

    The combined influences of a stress and a gaseous environment on materials can lead to brittleness and to unexpected delayed failure by stress corrosion cracking, fatigue cracking and creep. The most important parameters affering the material, the environment, the chemical reaction and the stress are emphasized and experimental works are described. Some trends for further research are given [fr

  12. Effect of the cooking method (grilling, roasting, frying and sous-vide) on the oxidation of thiols, tryptophan, alkaline amino acids and protein cross-linking in jerky chicken

    OpenAIRE

    Silva, Fábio A. P.; Ferreira, Valquíria C. S.; Madruga, Marta S.; Estévez, Mario

    2016-01-01

    Broiler breast (pectoralis major) meat was submitted to salting with NaCl + NaNO3 followed by a drying process to produce jerky-type chicken. The final product (raw broiler charqui) was desalted and then cooked using grilled, roasted, fried and sous-vide techniques. Sous-vide cooked samples showed lowest results of moisture loss compared to roasted and fried ones. Fatty acid profile suffered minor changes after cooking of broiler charqui. Regarding to protein oxidation, tryptophan fluorescenc...

  13. The dual role of microbes in corrosion.

    Science.gov (United States)

    Kip, Nardy; van Veen, Johannes A

    2015-03-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion.

  14. The dual role of microbes in corrosion

    Science.gov (United States)

    Kip, Nardy; van Veen, Johannes A

    2015-01-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion. PMID:25259571

  15. Corrosion engineering in nuclear power industry

    International Nuclear Information System (INIS)

    Prazak, M.; Tlamsa, J.; Jirousova, D.; Silber, K.

    1990-01-01

    Corrosion problems in nuclear power industry are discussed from the point of view of anticorrosion measures, whose aim is not only increasing the lifetime of the equipment but, first of all, securing ecological safety. A brief description is given of causes of corrosion damage that occurred at Czechoslovak nuclear power plants and which could have been prevented. These involve the corrosion of large-volume radioactive waste tanks made of the CSN 17247 steel and of waste piping of an ion exchange station made of the same material, a crack in a steam generator collector, contamination of primary circuit water with iron, and corrosion of CrNi corrosion-resistant steel in a spent fuel store. It is concluded that if a sufficient insight into the corrosion relationships exists and a reasonable volume of data is available concerning the corrosion state during the nuclear facility performance, the required safety can be achieved without adopting extremely costly anticorrosion measures. (Z.M.)

  16. Corrosion Rate Monitoring in District Heating Systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Nielsen, Lars Vendelbo; Andersen, A.

    2005-01-01

    be applicable, and if on-line monitoring could improve the quality control. Water quality monitoring was applied as well as corrosion rate monitoring with linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), electrical resistance (ER) technique, mass loss and a crevice corrosion......Quality control in district heating systems to keep uniform corrosion rates low and localized corrosion minimal is based on water quality control. Side-stream units equipped with carbon steel probes for online monitoring were mounted in district heating plants to investigate which techniques would...... cell for localized corrosion risk estimation. Important variations in corrosion rate due to changes in make-up water quality were detected with the continuous monitoring provided by ER and crevice cell, while LPR gave unreliable corrosion rates. The acquisition time of two-three days for EIS...

  17. Evolutionary Computation Techniques for Predicting Atmospheric Corrosion

    Directory of Open Access Journals (Sweden)

    Amine Marref

    2013-01-01

    Full Text Available Corrosion occurs in many engineering structures such as bridges, pipelines, and refineries and leads to the destruction of materials in a gradual manner and thus shortening their lifespan. It is therefore crucial to assess the structural integrity of engineering structures which are approaching or exceeding their designed lifespan in order to ensure their correct functioning, for example, carrying ability and safety. An understanding of corrosion and an ability to predict corrosion rate of a material in a particular environment plays a vital role in evaluating the residual life of the material. In this paper we investigate the use of genetic programming and genetic algorithms in the derivation of corrosion-rate expressions for steel and zinc. Genetic programming is used to automatically evolve corrosion-rate expressions while a genetic algorithm is used to evolve the parameters of an already engineered corrosion-rate expression. We show that both evolutionary techniques yield corrosion-rate expressions that have good accuracy.

  18. Corrosion mechanism applicable to biodegradable magnesium implants

    Energy Technology Data Exchange (ETDEWEB)

    Atrens, Andrej, E-mail: Andrejs.Atrens@uq.edu.au [University of Queensland, Division of Materials, Brisbane, Qld 4072 (Australia); Liu Ming; Zainal Abidin, Nor Ishida [University of Queensland, Division of Materials, Brisbane, Qld 4072 (Australia)

    2011-12-15

    Much of our understanding of the Mg corrosion mechanism is based on research using aggressive chloride based solutions like 3% NaCl, which are appropriate for understand the corrosion for applications such as auto construction. The chloride ions tend to cause break down of the partly protective surface film on the Mg alloy surface. The corrosion rate increases with exposure time until steady state is reached, which may take several weeks. An overview is provided of the aspects which determine the corrosion of Mg alloys: (i) measurement details; (ii) impurity elements Fe, Ni, Cu and Co; (iii) second phases; (iv) surface films and surface condition and (v) stress corrosion cracking (SCC). This understanding is used to help understand Mg corrosion for Mg as a biodegradable implant for medical applications. Solutions that elucidate these applications tend to form surface films and the corrosion rate tends to decrease with immersion time.

  19. Predicting the Performance of Organic Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    David A. Winkler

    2017-12-01

    Full Text Available The withdrawal of effective but toxic corrosion inhibitors has provided an impetus for the discovery of new, benign organic compounds to fill that role. Concurrently, developments in the high-throughput synthesis of organic compounds, the establishment of large libraries of available chemicals, accelerated corrosion inhibition testing technologies, and the increased capability of machine learning methods have made discovery of new corrosion inhibitors much faster and cheaper than it used to be. We summarize these technical developments in the corrosion inhibition field and describe how data-driven machine learning methods can generate models linking molecular properties to corrosion inhibition that can be used to predict the performance of materials not yet synthesized or tested. We briefly summarize the literature on quantitative structure–property relationships models of small organic molecule corrosion inhibitors. The success of these models provides a paradigm for rapid discovery of novel, effective corrosion inhibitors for a range of metals and alloys in diverse environments.

  20. Corrosion Control in the Aerospace Industry

    Science.gov (United States)

    Calle, Luz Marina; Li, Wenyan; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it..

  1. Corrosion of Metal-Matrix Composites with Aluminium Alloy Substrate

    Directory of Open Access Journals (Sweden)

    B. Bobic

    2010-03-01

    Full Text Available The corrosion behaviour of MMCs with aluminium alloy matrix was presented. The corrosion characteristics of boron-, graphite-, silicon carbide-, alumina- and mica- reinforced aluminium MMCs were reviewed. The reinforcing phase influence on MMCs corrosion rate as well as on various corrosion forms (galvanic, pitting, stress corrosion cracking, corrosion fatique, tribocorrosion was discussed. Some corrosion protection methods of aluminium based MMCs were described

  2. PH measurement under pressure and at high temperatures; Mesure du pH sous pression et a temperature elevee

    Energy Technology Data Exchange (ETDEWEB)

    Fournie, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Le Peintre, M; Mahieu, C [Centre National de la Recherche Scientifique (CNRS), 91 - Gif-sur-Yvette (France)

    1961-07-01

    In the first part the development and operation of a glass electrode under pressure at room temperature is described. The pressure equilibrium between the inside and outside of the glass membrane several centimetres thick is obtained instantaneously by means of a siphon. The use of a silicone oil as electrical insulator makes possible the working of the glass electrode with the siphon at high pressures (100 kg/cm{sup 2}). In the second part, we determined the pH of various buffer solutions up to 250 deg. C using a cell of our design having two hydrogen electrodes. The values thus obtained for the buffer solutions make it possible to verify and calibrate the pH electrodes independently of the oxido-reduction potential of the medium. In the third part we give the results obtained up to 200 deg. C with the glass electrodes developed in conjunction with the Societe St Gobain. (author) [French] Dans une premiere partie, nous exposons la mise au point et le fonctionnement d'une electrode en verre sous pression a la temperature ordinaire. L'equilibrage instantane de la pression a l'interieur et a l'exterieur de la membrane en verre de quelques diziemes de millimetres d'epaisseur s'effectue par l'intermediaire d'un siphon. L'emploi d'une huile de silicone comme isolant electrique a permis le fonctionnement de l'electrode en verre a siphon sous haute pression (1000 kg/cm{sup 2}). Dans une deuxieme partie, nous avons determine jusqu'a 250 deg. C les valeurs du pH des diverses solutions tampons avec une cellule de notre conception a deux electrodes d'hydrogene. Les valeurs des solutions tampons ainsi obtenues permettent de verifier et d'etalonner les electrodes a pH independantes du potentiel d'oxydo-reduction du milieu. Dans une troisieme partie, nous relatons les resultats obtenus jusqu'a 200 deg. C avec les electrodes en verre mis au point en collaboration avec la Societe Saint-Gobain. (auteur)

  3. NASA's Corrosion Technology Laboratory at the Kennedy Space Center: Anticipating, Managing, and Preventing Corrosion

    Science.gov (United States)

    Calle, Luz Marina

    2015-01-01

    The marine environment at NASAs Kennedy Space Center (KSC) has been documented by ASM International (formerly American Society for Metals) as the most corrosive in North America. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pads were rendered even more severe by the highly corrosive hydrochloric acid (HCl) generated by the solid rocket boosters (SRBs). Numerous failures at the launch pads are caused by corrosion. The structural integrity of ground infrastructure and flight hardware is critical to the success, safety, cost, and sustainability of space missions. NASA has over fifty years of experience dealing with unexpected failures caused by corrosion and has developed expertise in corrosion control in the launch and other environments. The Corrosion Technology Laboratory at KSC evolved, from what started as an atmospheric exposure test site near NASAs launch pads, into a capability that provides technical innovations and engineering services in all areas of corrosion for NASA, external partners, and customers.This paper provides a chronological overview of NASAs role in anticipating, managing, and preventing corrosion in highly corrosive environments. One important challenge in managing and preventing corrosion involves the detrimental impact on humans and the environment of what have been very effective corrosion control strategies. This challenge has motivated the development of new corrosion control technologies that are more effective and environmentally friendly. Strategies for improved corrosion protection and durability can have a huge impact on the economic sustainability of human spaceflight operations.

  4. Measurements for uranium-light water subcritical assembly; Mesures pour ensemble sous-critique uranium-eau legere d'enseignement

    Energy Technology Data Exchange (ETDEWEB)

    Barre, J Y [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1964-07-01

    The aim of this report is to determine the matter Laplacian of a subcritical assembly, done for educational purposes, using natural uranium combustible and light water for the moderator and the reflector. (M.B.) [French] L'objet de ce rapport est la determination du Laplacien matiere d'un reseau sous-critique, destine a l'enseignement, utilisant comme combustible l'uranium naturel et comme moderateur et reflecteur l'eau naturelle. (M.B.)

  5. Future and benefits of corrosion research

    International Nuclear Information System (INIS)

    Staehle, Roger W.

    2002-01-01

    The subject of corrosion is a design science. The subject of stress analysis is a design science as is the subject of heat transfer. When the subject of corrosion is considered in the framework design a clear framework of the priorities and objectives becomes apparent. Further, corrosion becomes a more explicit and important subject in the overall design, manufacturing, and operation phases of equipment: in this framework, the funding and support of corrosion work is necessary to the designers and users of equipment. The subject of corrosion is usually less important in the early stages of operation of equipment: in these early stages, the subjects. Corrosion becomes important to the longer term reliability and safety of equipment. Corrosion is often a principal determiner of design life. Corrosion is often more important after the manufacturing warranty is expired: therefore the subject is often more important to the user than to the manufacturer. In order that the subject of corrosion is considered and incorporated in the design as well as in user specifications, there must be a language and means of easily understood communication between the design-operation community and the corrosion community. For example, the designers do not understand the language of 'pitting potential': rather, they understand design life and permissible stress. Thus, corrosion must be put into terms that can be understood and utilized by designers and operators. Two methodologies have been developed for communicating effectively between the corrosion and the design communities: these are the 'Corrosion Based Design Approach' and the 'Location for Analysis Matrix.' These provide simple check off lists to designers for asking questions and assuring that credible answers have been obtained on issues that affect reliable and economic performance. Both of these subject are discussed in this presentation. The future of corrosion research is its effective linkage with design and operation of

  6. Corrosion Cost and Corrosion Map of Korea - Based on the Data from 2005 to 2010

    International Nuclear Information System (INIS)

    Kim, Y. S.; Lim, H. K.; Kim, J. J.; Hwang, W. S.; Park, Y. S.

    2011-01-01

    Corrosion of metallic materials occurs by the reaction with corrosive environment such as atmosphere, marine, soil, urban, high temperature etc. In general, reduction of thickness and cracking and degradation are resulted from corrosion. Corrosion in all industrial facilities and infrastructure causes large economic losses as well as a large number of accidents. Economic loss by corrosion has been reported to be nearly 1-6% of GNP or GDP. In order to reduce corrosion damage of industrial facilities, corrosion map as well as a systematic investigation of the loss of corrosion in each industrial sector is needed. The Corrosion Science Society of Korea in collaboration with 15 universities and institutes has started to survey on the cost of corrosion and corrosion map of Korea since 2005. This work presents the results of the survey on cost of corrosion by Uhlig, Hoar, and input-output methods, and the evaluation of atmospheric corrosion rate of carbon steel, weathering steel, galvanized steel, copper, and aluminum in Korea. The total corrosion cost was estimated in terms of the percentage of the GDP of industry sectors and the total GDP of Korea. According to the result of Input/output method, corrosion cost of Korea was calculated as 2.9% to GDP (2005). Time of wetness was shown to be categories 3 to 4 in all exposure areas. A definite seasonal difference was observed in Korea. In summer and fall, time of wetness was higher than in other seasons. Because of short exposure period (12 months), significant corrosion trends depending upon materials and exposure corrosion environments were not revealed even though increased mass loss and decreased corrosion rate by exposure time

  7. Application of Advanced Material for Turbomachinery and Rocket Propulsion

    Science.gov (United States)

    1988-10-01

    de fatigue oligocyclique sous charges nominales a 6t6 r~alisi avec succ~s. L’instrumentation en jauges de contrainte a confirm6 lea niveaux de...thermocouples, peintures thermosensibles et jauges de contraintes de fagon A mieux 6valuer leur comportement dans l’environnement du moteur. Aucune anomalie n’s

  8. Microfracture pattern compared to core-scale fractures in the borehole of Soultz-sous-Forets granite, Rhine graben, France

    Energy Technology Data Exchange (ETDEWEB)

    Dezayes, C.; Villemin, T. [Universite de Savoie (France). Laboratoire de Geodynamique des Chaines Alpines, UPRES-A CNRS 5025; Pecher, A. [Universite Joseph Fourier, Grenoble (France). Laboratoire de Geodynamique des Chaines Alpines, UPRES-A CNRS 5025

    2000-07-01

    Microfractures appearing in thin section as fluid inclusion trails in quartz crystals were studied in four core samples of Soultz-sous-Forets granite. Their orientations in four series of three mutually perpendicular thin sections were estimated using a previously described apparent dip method and a new method involving measurements of strike and apparent dips. Three samples display three microfracture sets and one sample displays two sets. In all samples, one set is nearly vertical and strikes N-S. In two samples, one and two sets are nearly vertical and strike E-W. In two samples, two sets strike NW-SE: one is vertical, the other dips gently to the NE (or SW). Comparing microfracture and mesofractures sets in the same cores shows that (1) the N-S microfacture set is always dominant at both scales and (2) all other microfracture sets have no mesoscopic counterpart. The N-S microfracture sets could have been created during E-W extension of earliest Cenozoic age (Rhine Graben rifting). Differences between the two scales are explained by a {sigma}{sub 1}/{sigma}{sub 2} switching which occurred at the crystal scale and generated mutually perpendicular cracks.

  9. Studies and support for the EGS reservoirs at Soultz-sous-Forets. April 2004 - May 2009. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Portier, S.; Vuataz, F.-D. [Centre de Recherche en Geothermie (CREGE), Neuchatel (Switzerland)

    2009-08-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at the activities carried out during the period from April 2004 up to May 2009 at Soultz-sous-Forets, France, in connection with the enhanced geothermal systems (EGS) at that location. The report describes the work performed by the Swiss EGS Research and Development group involved in the Soultz project. The principal target set was to install and operate a power plant, enabling the deep reservoir/heat exchanger to be operated, evaluated and improved under realistic conditions. The Swiss contributors have been participating in several work packages: Short and long term tests and medium-term tests of the three-well reservoir/heat exchanger system, development and up-scaling, technical and economic design of larger, industrial, EGS units and the development of stimulation methodology for EGS. The exchange of findings obtained during this project phase is discussed, as is the state-of-the-art of EGS stimulation methods, the interpretation of logging data. Also, seismic /-hydraulic factors, the evaluation of the production/injection performance of the boreholes and reservoir development strategies are discussed as are the modelling of geochemical impact of forced fluid circulation in the deep geothermal reservoir and the results of chemical stimulation tests performed on site.

  10. Efficacy of Combined Sous Vide-Microwave Cooking for Foodborne Pathogen Inactivation in Ready-to-Eat Chicory Stems.

    Science.gov (United States)

    Renna, Massimiliano; Gonnella, Maria; de Candia, Silvia; Serio, Francesco; Baruzzi, Federico

    2017-07-01

    There is a variety of different food processing methods, which can be used to prepare ready-to-eat foods. However, the need to preserve the freshness and nutritional qualities leads to the application of mild technologies which may be insufficient to inactivate microbial pathogens. In this work, fresh chicory stems were packed under a vacuum in films, which were transparent to microwaves. These were then exposed to microwaves for different periods of time. The application of sous vide microwave cooking (SV-MW, 900 W, 2450 MHz), controlled naturally occurring mesophilic aerobic bacteria, yeasts and molds for up to 30 d when vacuum-packed vegetables were stored at 4 °C. In addition, the process lethality of the SV-MW 90 s cooking was experimentally validated. This treatment led to 6.07 ± 0.7 and 4.92 ± 0.65 log cfu/g reduction of Escherichia coli and Listeria monocytogenes inoculated over the chicory stems (100 g), respectively. With an initial load of 9 log cfu/g for both pathogens, less than 10 cfu/g of surviving cells were found after 90 s cooking. This shows that short-time microwave cooking can be used to effectively pasteurize vacuum-packed chicory stems, achieving >5 log cfu/g reduction of E. coli and L. monocytogenes. © 2017 Institute of Food Technologists®.

  11. Electrochemical characterisation speeds up prediction of corrosion behaviour

    Energy Technology Data Exchange (ETDEWEB)

    Schuring, E.W.; Hooijmans, J.W. [ECN Environment and Energy Engineering, Petten (Netherlands)

    2013-04-15

    The contents of this presentation show the following elements: Introduction; Corrosion in real life; Why Electrochemical characterisation of corrosion; Applications (corrosion resistance coatings, corrosion behaviour (brazed) joints); Available electrochemical corrosion techniques; Standards; Conclusions. In the Conclusions the corrosion screening method is summarized: ECN method fast; within 1h -1 week results depending on test method; Fast pre-selection of promising materials/combinations (cost savings); Determining of corrosion initiation; Determination of corrosion mechanisms and propagation; Life time predictions possible; Strong combination with metallographic post-investigation; Ranking materials / constructions for corrosion performance.

  12. Corrosion strength monitoring of NPP component residual lifetime

    International Nuclear Information System (INIS)

    Denisov, V.G.; Belous, V.N.; Arzhaev, A.I.; Shuvalov, V.A.

    1994-01-01

    Importance of corrosion and fatigue monitoring; types of corrosion determine the NPP equipment life; why automated on-line corrosion and fatigue monitoring is preferable; major stages of lifetime monitoring system development; major groups of sensors for corrosion and strength monitoring system; high temperature on-line monitoring of water chemistry and corrosion; the RBMK-1000 NPP unit automatic water chemistry and corrosion monitoring scheme; examples of pitting, crevice and general corrosion forecast calculations on the basis of corrosion monitoring data; scheme of an experimental facility for water chemistry and corrosion monitoring sensor testing. 2 figs., 4 tabs

  13. Microencapsulation Technology for Corrosion Mitigation by Smart Coatings

    Science.gov (United States)

    Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.

    2011-01-01

    A multifunctional, smart coating for the autonomous control of corrosion is being developed based on micro-encapsulation technology. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection effectiveness. This paper summarizes the development, optimization, and testing of microcapsules specifically designed to be incorporated into a smart coating that will deliver corrosion inhibitors to mitigate corrosion autonomously. Key words: smart coating, corrosion inhibition, microencapsulation, microcapsule, pH sensitive microcapsule, corrosion inhibitor, corrosion protection pain

  14. Corrosion characteristics of K-claddings

    International Nuclear Information System (INIS)

    Park, J. Y.; Choi, B. K.; Jung, Y. H.; Jung, Y. H.

    2004-01-01

    The Improvement of the corrosion resistance of nuclear fuel claddings is the critical issue for the successful development of the high burn-up fuel. KAERI have developed the K-claddings having a superior corrosion resistance by controlling the alloying element addition and optimizing the manufacturing process. The comparative evaluation of the corrosion resistance for K-claddings and the foreign claddings was performed and the effect of the heat treatment on the corrosion behavior of K-claddings was also examined. Corrosion tests were carried out in the conditions of 360 .deg. C pure water, PWR-simulating loop and 400 .deg. C steam, From the results of the corrosion tests, it was found that the corrosion resistance of K-claddings is superior to those of Zry4 and A claddings and K6 showed a better corrosion resistance than K3. The corrosion behavior of K-cladding was strongly influenced by the final annealing rather than the intermediate annealing, and the corrosion resistance increased with decreasing the final annealing temperature

  15. Current status of studies on nodular corrosion

    International Nuclear Information System (INIS)

    Yasuda, Takayoshi; Kawasaki, Satoru; Echigoya, Hironori; Kinoshita, Yutaka; Kubota, Hiroyuki; Konishi, Takao; Yamanaka, Tuneyasu.

    1993-01-01

    The studies on nodular corrosion formed on the outer surface of BWR fuel cladding tubes were reviewed. Main factors affecting the corrosion behavior were material and environmental conditions and combined effect. The effects of such material conditions as fabrication process, alloy elements, texture and surface treatment and environmental factors as neutron irradiation, thermo-hydrodynamic, water chemistry, purity of the coolant and contact with foreign metals on the corrosion phenomena were surveyed. Out-of-reactor corrosion test methods and models for the corrosion mechanism were also reviewed. Suppression of the accumulated annealing temperature during tube reduction process improved the nodular corrosion resistance of Zircaloys. Improved resistance for the nodular corrosion was reported for the unirradiated Zircaloys with some additives. Detailed irradiation test under the BWR conditions is needed to confirm the trend. Concerning the environmental factors, boiling on the cladding surface due to heat flux reduces the nodular corrosion susceptibility, while oxidizing radical generated from dissolved oxygen accelerates the corrosion. Concerning corrosion mechanisms, importance of such phenomena as the depleted zone of alloying elements in zirconium matrix, reduction of H + to H 2 in oxide layer, electrochemical property of precipitates, crystallographic anisotropy of oxidation rates were revealed. (author) 59 refs

  16. Protecting solar collector systems from corrosion

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    The main cause of the reduced life of a solar heating system is corrosion of the exterior parts and the internal components. This report outlines ways of reducing the cost of solar heating by reducing the corrosion in solar heating systems, and hence increasing the system's service life. Mechanisms for corrosion are discussed: these include galvanic corrosion and crevice corrosion. Means of minimizing corrosion at the design stage are then described. Such methods, when designing the solar collector, involve ensuring proper drainage of exterior water; eliminating situations where moisture, dirt and pollutants may collect; preventing condensation inside the collector; using proper gaskets and sealants at appropriate places; and selecting optimum materials and coatings. Interior corrosion can be minimized at the design stage by choosing a good heat transfer fluid and corrosion inhibitor, in the case of systems where liquids are used; ensuring a low enough flow rate to avoid erosion; designing the system to avoid crevices; and avoiding situations where galvanic corrosion could occur. Other procedures are given for minimizing corrosion in the construction and operation of solar heating systems. 7 figs., 7 tabs.

  17. Corrosion and protection of magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ghali, E. [Laval Univ., Quebec City, PQ (Canada). Dept. of Mining and Metallurgy

    2000-07-01

    The oxide film on magnesium offers considerable surface protection in rural and some industrial environments and the corrosion rate lies between that of aluminum and low carbon steels. Galvanic coupling of magnesium alloys, high impurity content such as Ni, Fe, Cu and surface contamination are detrimental for corrosion resistance of magnesium alloys. Alloying elements can form secondary particles which are noble to the Mg matrix, thereby facilitating corrosion, or enrich the corrosion product thereby possibly inhibiting the corrosion rate. Bimetallic corrosion resistance can be increased by fluxless melt protection, choice of compatible alloys, insulating materials, and new high-purity alloys. Magnesium is relatively insensible to oxygen concentration. Pitting, corrosion in the crevices, filiform corrosion are observed. Granular corrosion of magnesium alloys is possible due to the cathodic grain-boundary constituent. More homogeneous microstructures tend to improve corrosion resistance. Under fatigue loading conditions, microcrack initiation in Mg alloys is related to slip in preferentially oriented grains. Coating that exclude the corrosive environments can provide the primary defense against corrosion fatigue. Magnesium alloys that contain neither aluminum nor zinc are the most SCC resistant. Compressive surface residual stresses as that created by short peening increase SCC resistance. Cathodic polarization or cladding with a SCC resistant sheet alloy are good alternatives. Effective corrosion prevention for magnesium alloy components and assemblies should start at the design stage. Selective surface preparation, chemical treatment and coatings are recommended. Oil application, wax coating, anodizing, electroplating, and painting are possible alternatives. Recently, it is found that a magnesium hydride layer, created on the magnesium surface by cathodic charging in aqueous solution is a good base for painting. (orig.)

  18. Degradation of aged plants by corrosion: 'Long cell action' in unresolved corrosion issues

    International Nuclear Information System (INIS)

    Saji, Genn

    2009-01-01

    In a series of previously published papers the author has identified that 'long cell action' corrosion plays a pivotal role in practically all unresolved corrosion issues for all types of nuclear power plants (e.g. PWR/VVER, BWR/RBMK and CANDU). Some of these unresolved issues are IGSCC, PWSCC, AOA and FAC (erosion-corrosion). In conventional corrosion science it is well established that 'long cell action' can seriously accelerate or suppress the local cell corrosion activities. Although long cell action is another fundamental mechanism of corrosion, especially in a 'soil corrosion' arena, potential involvement of this corrosion process has never been studied in nuclear and fossil power plants as far as the author has been able to establish. The author believes that the omission of this basic corrosion mechanism is the root cause of practically all un-resolved corrosion issues. In this paper, the author further elaborated on his assessment to other key corrosion issues, e.g. steam generator and turbine corrosion issues, while briefly summarizing previous discussions for completeness purposes, as well as introducing additional experimental and theoretical evidence of this basic corrosion mechanism. Due to the importance of this potential mechanism the author is calling for institutional review activities and further verification experiments in the form of a joint international project.

  19. 49 CFR 192.477 - Internal corrosion control: Monitoring.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control: Monitoring. 192.477... Control § 192.477 Internal corrosion control: Monitoring. If corrosive gas is being transported, coupons... internal corrosion. Each coupon or other means of monitoring internal corrosion must be checked two times...

  20. Nuclear waste glass corrosion mechanisms

    International Nuclear Information System (INIS)

    Jantzen, C.M.

    1987-04-01

    Dissolution of nuclear waste glass occurs by corrosion mechanisms similar to those of other solids, e.g., metallurgical and mineralogic systems. Metallurgical phenomena such as active corrosion, passivation and immunity have been observed to be a function of the glass composition and the solution pH. Hydration thermodynamics was used to quantify the role of glass composition and its effect on the solution pH during dissolution. A wide compositional range of natural, lunar, medieval, and nuclear waste glasses, as well as some glass-ceramics were investigated. The factors observed to affect dissolution in deionized water are pertinent to the dissolution of glass in natural environments such as the groundwaters anticipated to interact with nuclear waste glass in a geologic repository. The effects of imposed pH and oxidation potential (Eh) conditions existing in natural environments on glass dissolution is described in the context of Pourbaix diagrams, pH potential diagrams, for glass

  1. Mechanisms of metal dusting corrosion

    DEFF Research Database (Denmark)

    Hummelshøj, Thomas Strabo

    In this thesis the early stages of metal dusting corrosion is addressed; the development of carbon expanded austenite, C, and the decomposition hereof into carbides. Later stages of metal dusting corrosion are explored by a systematic study of stainless steel foils exposed to metal dusting...... deformed stainless steel flakes is transformed to expanded martensite/austenite during low-temperature carburization. Various experimental procedures to experimentally determine the concentration dependent diffusion coefficient of carbon in expanded austenite are evaluated. The most promising procedure...... powders and flakes. The nature of the decomposition products, carbides of the form M23C6 and M7C3, were evaluated by X-ray diffraction, light optical microscopy, scanning electron microscopy and thermodynamic modelling. The decomposition was found to be dependent on several parameters such as thermal...

  2. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    Daniel, B.

    1988-09-01

    This report assesses the factors which cause preferential attack to occur in carbon steel fusion welds. It was concluded that the main factors were: the inclusion content of the weld metal, the potential of the weld metal being less noble than that of the parent, and the presence of low-temperature transformation products in the heat-affected zone of the weld. These factors should be minimized or eliminated as appropriate so that the corrosion allowances determined for carbon steel waste drums is also adequate for the welds. An experimental/theoretical approach is recommended to evaluate the relative corrosion resistance of welds prepared from BS 4360 grade 43A steel to that of the parent material. (author)

  3. Tri-Service Corrosion Conference

    Science.gov (United States)

    2002-01-18

    Video- Thermographie. M.S. Thesis, University Magdeburg , Germany 5. N. Meyendorf et al. (2001) Early Detection of Corrosion in Aircraft Structures...We serve as a bridge between developers and users, helping transition technologies into operational use. For more information, contact: Major...scrapers, tractors, fork lifts and material trucks. • Engineer-Trlr - trailered engineering equipment including, fixed bridge , fuel pump module, water

  4. Stress Corrosion of Ceramic Materials.

    Science.gov (United States)

    1986-08-01

    rupture directly, or are hydrolyzed by the water in the environment. This type of reaction is known to be important to the corrosion of glass in basic...covered .ith silanol groups so that the surface is virtually uncharged. As the pH is increased, the surface gradually hydrolyzes forming silanolate...is plotted assuming a decay distance of 0.3 nm. The data on lecithin is obtained by a non-fracture technique in which the layer spacing is determined

  5. Corrosion and Corrosion Fatigue of Aluminum Alloys: Chemistry, Micromechanics and Reliability

    National Research Council Canada - National Science Library

    Wei, Robert

    1998-01-01

    ... No. F49620-98-1-0198, to further develop a basic mechanistic understanding of the damage evolution processes of localized corrosion and corrosion fatigue crack nucleation and growth in aluminum alloys...

  6. Chemical cleaning, decontamination and corrosion

    International Nuclear Information System (INIS)

    Gadiyar, H.S.; Das Chintamani; Gaonkar, K.B.

    1991-01-01

    Chemical cleaning of process equipments and pipings in chemical/petrochemical industries is necessitated for improving operation, for preventing premature failures and for avoiding contamination. In developing a chemical formulation for cleaning equipments, the important aspects to be considered include (i) effective removal of corrosion products and scales, (ii) minimum corrosion of the base metal, (iii) easy to handle chemicals and (iv) economic viability. As on date, a wide variety of chemical formulations are available, many of them are either proprietory or patented. For evolving an effective formulation, knowledge of the oxides of various metals and alloys on the one hand and acid concentration, complexing agents and inhibitors to be incorporated on the other, is quite essential. Organic acids like citric acid, acetic acid and formic acid are more popular ones, often used with EDTA for effective removal of corrosion products from ferrous components. The report enumerates some of the concepts in developing effective formulations for chemical cleaning of carbon steel components and further, makes an attempt to suggest simple formulations to be developed for chemical decontamination. (author). 6 refs., 3 fi gs., 4 tabs

  7. Galvanic corrosion of beryllium welds

    International Nuclear Information System (INIS)

    Hill, M.A.; Butt, D.P.; Lillard, R.S.

    1997-01-01

    Beryllium is difficult to weld because it is highly susceptible to cracking. The most commonly used filler metal in beryllium welds is Al-12 wt.% Si. Beryllium has been successfully welded using Al-Si filler metal with more than 30 wt.% Al. This filler creates an aluminum-rich fusion zone with a low melting point that tends to backfill cracks. Drawbacks to adding a filler metal include a reduction in service temperature, a lowering of the tensile strength of the weld, and the possibility for galvanic corrosion to occur at the weld. To evaluate the degree of interaction between Be and Al-Si in an actual weld, sections from a mock beryllium weldment were exposed to 0.1 M Cl - solution. Results indicate that the galvanic couple between Be and the Al-Si weld material results in the cathodic protection of the weld and of the anodic dissolution of the bulk Be material. While the cathodic protection of Al is generally inefficient, the high anodic dissolution rate of the bulk Be during pitting corrosion combined with the insulating properties of the Be oxide afford some protection of the Al-Si weld material. Although dissolution of the Be precipitate in the weld material does occur, no corrosion of the Al-Si matrix was observed

  8. Metal corrosion inhibitors and ecology

    International Nuclear Information System (INIS)

    Krasts, H.; Svarce, J.; Berge, B.

    1999-01-01

    The use of metal corrosion inhibitors in water is one of the cheapest method to protect metals against corrosion. However, the used inhibitors can come to surface water in the course of time and can become as source of environmental pollution. It is important to co-ordinate amount of substances in the elaborated inhibitors not only with demands for metal protection, but also with demands for quality of surface water and drinking water according to normative statements: 3.5 mg/l (as PO 4 ) for hexametaphosphate, tripolyphosphate and phosphonate; 40 mg/l (as SiO 2 for silicate, up to 1 mg/l for CU 2+ ; up to 5 mg/l for Zn 2+ ; up to 1 mg/l for B; up to 0.5 mg/l for Mo 2+ . The examples of the elaborated inhibitors are given. Many organic substances can be used as corrosion inhibitors, but there is shortage of standard methods for their analysis in water in Latvia. Removing of salt's deposits from boilers needs elaboration of a separate normative statement for dispersing waste water which content chloride at high concentration and heavy metals. (authors)

  9. Aluminum corrosion product release kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, Matt, E-mail: Matthew.Edwards@cnl.ca; Semmler, Jaleh; Guzonas, Dave; Chen, Hui Qun; Toor, Arshad; Hoendermis, Seanna

    2015-07-15

    Highlights: • Release of Al corrosion product was measured in simulated post-LOCA sump solutions. • Increased boron was found to enhance Al release kinetics at similar pH. • Models of Al release as functions of time, temperature, and pH were developed. - Abstract: The kinetics of aluminum corrosion product release was examined in solutions representative of post-LOCA sump water for both pressurized water and pressurized heavy-water reactors. Coupons of AA 6061 T6 were exposed to solutions in the pH 7–11 range at 40, 60, 90 and 130 °C. Solution samples were analyzed by inductively coupled plasma atomic emission spectroscopy, and coupon samples were analyzed by secondary ion mass spectrometry. The results show a distinct “boron effect” on the release kinetics, expected to be caused by an increase in the solubility of the aluminum corrosion products. New models were developed to describe both sets of data as functions of temperature, time, and pH (where applicable)

  10. Corrosion of steel in concrete

    International Nuclear Information System (INIS)

    Preece, C.M.

    1982-10-01

    A comparative study has been made of those properties of Massiv and Standard cements which are considered to determine their ability to protect steel reinforcement from corroding. Saturated Massiv cement has a higher evaporabel water content, but a significantly finer pore structure than has saturated Standard cement. This fine structure resulted in an electrical resistivity ten times higher and chloride diffusivity ten times lower than those of Standard cement. Electrochemical measurements have shown that the passive current density of steel in Massiv mortar is higher than that of steel in Standard mortar, but the higher current should lead to a more rapid decrease in potential to a level at which neither chloride attack of hydrogen evolution will occur. Whereas steel in Standard mortar was found to be highly susceptible to crevice corrosion, no such attack has been observed in Massiv mortar. Moreover, the initiation of chloride induced corrosion and the subsequent rates of corrosion were both lower in Massiv mortar than in Standard mortar. Thus, it may be predicted that Massiv cement would provide greater protection for steel reinforcement in underground structures exposed to chloride containing ground water than would Standard cement. (author)

  11. Evaluation of corrosion attack of chimney liners

    Directory of Open Access Journals (Sweden)

    Blahetová M.

    2016-06-01

    Full Text Available The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241 was particularly high content of halides (chlorides and fluorides, which caused a severe pitting corrosion, which led up to the perforation of the liner material. Simultaneous reduction of the thickness of the used sheets was due to by the general corrosion, which was caused by the sulfur in the solid fuel. The condensation then led to acid environment and therefore the corrosion below the dew point of the sulfuric acid has occurred. All is documented by metallographic analysis and microanalysis of the corrosion products.

  12. Electrochemical corrosion testing of metal waste forms

    International Nuclear Information System (INIS)

    Abraham, D. P.; Peterson, J. J.; Katyal, H. K.; Keiser, D. D.; Hilton, B. A.

    1999-01-01

    Electrochemical corrosion tests have been conducted on simulated stainless steel-zirconium (SS-Zr) metal waste form (MWF) samples. The uniform aqueous corrosion behavior of the samples in various test solutions was measured by the polarization resistance technique. The data show that the MWF corrosion rates are very low in groundwaters representative of the proposed Yucca Mountain repository. Galvanic corrosion measurements were also conducted on MWF samples that were coupled to an alloy that has been proposed for the inner lining of the high-level nuclear waste container. The experiments show that the steady-state galvanic corrosion currents are small. Galvanic corrosion will, hence, not be an important mechanism of radionuclide release from the MWF alloys

  13. Corrosion monitoring during a chemical cleaning

    International Nuclear Information System (INIS)

    Delepine, J.; Feron, D.; Roy, M.

    1994-01-01

    In order to estimate the possible corrosion induced by the chemical cleaning, a corrosion monitoring has been realized during the cleaning of the secondary circuit (including the model boiler) of ORION loop. It included coupons and electrodes and has required a preliminary setting in laboratory. The electrochemical device which was used during the chemical cleaning included two reference electrodes (Ag/AgCl) and eight metallic electrodes (carbon steel, stainless steel, Alloy 600 and Alloy 690) for free corrosion potential monitoring, three other carbon steel electrodes for instantaneous corrosion rate measurements by polarization resistance and three coupling devices with different surface ratios between carbon steel and Alloy 600. The results showed a good agreement between corrosion rates measured by weight losses on coupons or by electrochemistry (polarization resistance), and an increase of the carbon steel corrosion rate when it was coupled with Alloy 600. (authors). 5 figs., 2 tabs., 3 refs

  14. Corrosion-Activated Micro-Containers for Environmentally Friendly Corrosion Protective Coatings

    Science.gov (United States)

    Li, Wenyan; Buhrow, J. W.; Zhang, X.; Johnsey, M. N.; Pearman, B. P.; Jolley, S. T.; Calle, L. M.

    2016-01-01

    This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry. The NASA Kennedy Space Centers Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion

  15. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove

    1997-01-01

    In this paper the corrosion properties of laser welded AISI 316L stainless steel are examined. A number of different welds has been performed to test the influence of the weld parameters of the resulting corrosion properties. It has been chosen to use the potential independent critical pitting...... temperature (CPT) test as corrosion test. The following welding parameters are varied: Welding speed, lsser power, focus point position and laser operation mode (CW or pulsed)....

  16. Natural analogues of nuclear waste glass corrosion

    International Nuclear Information System (INIS)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-01

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses

  17. Internal corrosion control of northern pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Papavinasam, S.

    2005-02-01

    The general causes of internal corrosion in pipelines were discussed along with the methods to control them. Efficient methods are needed to determine chemical efficiency for mitigating internal corrosion in transmission pipelines, particularly those used in environmentally sensitive regions in the Arctic where harsh environmental conditions prevail. According to the Office of Pipeline Safety, 15 per cent of pipeline failures in the United States from 1994 to 2000 were caused by internal corrosion. Since pipelines in the United States are slightly older than Canadian pipelines, internal corrosion is a significant issue from a Canadian perspective. There are 306,618 km of energy-related pipelines in western Canada. Between April 2001 and March 2002 there were 808 failures, of which 425 failures resulted from internal corrosion. The approach to control internal corrosion comprises of dehydrating the gases at production facilities; controlling the quality of corrosive gases such as carbon dioxide and hydrogen sulphide; and, using internal coatings. The approaches to control internal corrosion are appropriate, when supplemented by adequate integrity management program to ensure that corrosive liquids do not collect, over the operational lifetime of the pipelines, at localized areas. It was suggested that modeling of pipeline operations may need improvement. This paper described the causes, prediction and control of internal pitting corrosion. It was concluded that carbon steel equipment can continue to be used reliably and safely as pipeline materials for northern pipelines if the causes that lead to internal corrosion are scientifically and accurately predicted, and if corrosion inhibitors are properly evaluated and applied. 5 figs.

  18. Anodizing of aluminum with improved corrosion properties

    International Nuclear Information System (INIS)

    John, P.; Khan, I.U.

    2010-01-01

    Anodizing of aluminum was studied in sulphuric/oxalic/boric acid electroiyte system. The corrosion resistance of the anodic oxide coating of aluminum was determined by potentiodynamic polarization test and scanning electron microscope (SEM) was used to investigate the surface morphology before and after corrosion test. It was found that the oxide coating obtained by this method showed better corrosion resistance with no significant difference in surface morphology. (author)

  19. Preventing Corrosion by Controlling Cathodic Reaction Kinetics

    Science.gov (United States)

    2016-03-25

    3. DATES COVERED (From - To) 09/23/15 - 04/22/16 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Preventing Corrosion by Controlling Cathodic Reaction...Preventing corrosion by controlling cathodic reaction kinetics Progress Report for Period: 1 SEP 2015-31 MAR 2016 John Keith Department of...25 March 2016 Preventing corrosion by controlling cathodic reaction kinetics Annual Summary Report: FY16 PI: John Keith, 412-624-7016,jakeith

  20. Recognition and Analysis of Corrosion Failure Mechanisms

    OpenAIRE

    Steven Suess

    2006-01-01

    Corrosion has a vast impact on the global and domestic economy, and currently incurs losses of nearly $300 billion annually to the U.S. economy alone. Because of the huge impact of corrosion, it is imperative to have a systematic approach to recognizing and mitigating corrosion problems as soon as possible after they become apparent. A proper failure analysis includes collection of pertinent background data and service history, followed by visual inspection, photographic documentation, materi...

  1. The oxidation and corrosion of ODS alloys

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.

    1990-01-01

    The oxidation and hot corrosion of high temperature oxide dispersion strengthened (ODS) alloys are reviewed. The environmental resistance of such alloys are classified by oxide growth rate, oxide volatility, oxide spalling, and hot corrosion limitations. Also discussed are environmentally resistant coatings for ODS materials. It is concluded that ODS NiCrAl and FeCrAl alloys are highly oxidation and corrosion resistant and can probably be used uncoated.

  2. Oxidation And Hot Corrosion Of ODS Alloy

    Science.gov (United States)

    Lowell, Carl E.; Barrett, Charles A.

    1993-01-01

    Report reviews oxidation and hot corrosion of oxide-dispersion-strengthened (ODS) alloys, intended for use at high temperatures. Classifies environmental resistances of such alloys by rates of growth of oxides, volatilities of oxides, spalling of oxides, and limitations imposed by hot corrosion. Also discusses environmentally resistant coatings for ODS materials. Concludes ODS NICrAl and FeCrAl alloys highly resistant to oxidation and corrosion and can be used uncoated.

  3. Ferritic stainless steels: corrosion resistance + economy

    International Nuclear Information System (INIS)

    Remus, A.L.

    1976-01-01

    Ferritic stainless steels provide corrosion resistance at lower cost. They include Type 409, Type 439, 18SR, 20-Mo (1.6 Mo), 18-2 (2 Mo), 26-1S, E-Brite 26-1, 29 Cr-4 Mo, and 29 Cr-4 Mo-2 Ni. Their corrosion and mechanical properties are examined. Resistance to stress-corrosion cracking is an advantage compared to austenitic types

  4. Natural analogues of nuclear waste glass corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Abrajano, T.A. Jr.; Ebert, W.L.; Luo, J.S.

    1999-01-06

    This report reviews and summarizes studies performed to characterize the products and processes involved in the corrosion of natural glasses. Studies are also reviewed and evaluated on how well the corrosion of natural glasses in natural environments serves as an analogue for the corrosion of high-level radioactive waste glasses in an engineered geologic disposal system. A wide range of natural and experimental corrosion studies has been performed on three major groups of natural glasses: tektite, obsidian, and basalt. Studies of the corrosion of natural glass attempt to characterize both the nature of alteration products and the reaction kinetics. Information available on natural glass was then compared to corresponding information on the corrosion of nuclear waste glasses, specifically to resolve two key questions: (1) whether one or more natural glasses behave similarly to nuclear waste glasses in laboratory tests, and (2) how these similarities can be used to support projections of the long-term corrosion of nuclear waste glasses. The corrosion behavior of basaltic glasses was most similar to that of nuclear waste glasses, but the corrosion of tektite and obsidian glasses involves certain processes that also occur during the corrosion of nuclear waste glasses. The reactions and processes that control basalt glass dissolution are similar to those that are important in nuclear waste glass dissolution. The key reaction of the overall corrosion mechanism is network hydrolysis, which eventually breaks down the glass network structure that remains after the initial ion-exchange and diffusion processes. This review also highlights some unresolved issues related to the application of an analogue approach to predicting long-term behavior of nuclear waste glass corrosion, such as discrepancies between experimental and field-based estimates of kinetic parameters for basaltic glasses.

  5. Optimising corrosion monitoring in district heating systems

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel; Thorarinsdottir, R.I.; Andersen, A.

    2002-01-01

    A three-year project - financially supported by the Nordic Industrial Fund - on monitoring of corrosion in district heating systems has been initiated with participation of researchers and industrial partners in Denmark, Finland, Iceland, Norway and Sweden. The primary objective of the project...... is to improve the quality control in district heating systems by corrosion monitoring. In Danish systems electrochemical impedance spectroscopy (EIS), linear polarisation resistance (LPR), high-sensitive electrical resistance (ER) technology, crevice corrosion probes, as well as weight loss coupons...

  6. Colorimetric visualization of tin corrosion: A method for early stage corrosion detection on printed circuit boards

    DEFF Research Database (Denmark)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2017-01-01

    A majority of printed circuit board surfaces are covered with tin, therefore tin corrosion under humid conditions and movement of tin ions under the influence of an electric field plays an important role in the corrosion failure development. Tracking tin corrosion products spread on the printed c...

  7. Corrosion problems of PWR steam generators

    International Nuclear Information System (INIS)

    Urbancik, L.; Kostal, M.

    Literature data are assessed on corrosion failures of steam generator tubes made of INCONEL 600 or INCOLOY 800. It was found that both alloys with high nickel content showed good stability in a corrosion environment while being sensitive to carbide formation on grain boundaries. The gradual depletion of chromium results from the material and corrosion resistance deteriorates. INCOLOY 800 whose chromium carbide precipitation on grain boundaries in pure water and steam is negligible up to 75O degC and which is not subject to corrosion attacks in the above media and in an oxidizing environment at a temperature to about 700 degC shows the best corrosion resistance. Its favourable properties were tested in long-term operation in the Peach Bottom 1 nuclear power plant where no failures due to corrosion of this material have been recorded since 1967. In view of oxygenic-acid surface corrosion, it is necessary to work in a neutral or slightly basic environment should any one of the two alloys be used for steam generator construction. The results are summed up of an analysis conducted for the Beznau I NOK reactor. Water treatment with ash-free amines can be used as prevention against chemical corrosion mechanisms, although the treatment itself does not ensure corrosion resistance of steam generator key components. (J.B.)

  8. New corrosion issues in gas sweetening plants

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G. (CLI International and Asperger Technologies, Houston, TX (United States))

    Gas treating plants are experiencing corrosion problems which impact on efficiency and safety. While general corrosion is not particularly hazardous in the gas processing industry, local corrosion is very dangerous since it has several different mechanisms, all of which have dangerously high rates, and it occurs at locations which are hard to find and hard to predict. A newly discovered, velocity-dependent type of corrosion is reported. It is related to yet-undefined species which cause excessively high corrosion in areas of turbulence. This accelerated corrosion is not due to erosion or cavitation, but to a diffusion-limited reaction accelerated by turbulence. A full-flow test loop was built to evaluate the corrosiveness of gas plant solutions at their normal temperature and flow rates. Test runs were conducted with Co[sub 2]-loaded amine solutions for periods of 12 days. Carbon steel specimens mounted in the test loop were examined and corrosion rates calculated. Chromium alloys were shown to be attacked by corrodents in the low-velocity part of the loop and very aggressively attacked in the high-velocity part. The tests demonstrate the need for rigorous monitoring of corrosion in areas of higher velocity such as piping elbows and other points of turbulence. 5 refs., 2 figs., 3 tabs.

  9. Boric Acid Corrosion of Concrete Rebar

    Directory of Open Access Journals (Sweden)

    Yang L.

    2013-07-01

    Full Text Available Borated water leakage through spent fuel pools (SFPs at pressurized water reactors is a concern because it could cause corrosion of reinforcement steel in the concrete structure and compromise the integrity of the structure. Because corrosion rate of carbon steel in concrete in the presence of boric acid is lacking in published literature and available data are equivocal on the effect of boric acid on rebar corrosion, corrosion rate measurements were conducted in this study using several test methods. Rebar corrosion rates were measured in (i borated water flowing in a simulated concrete crack, (ii borated water flowing over a concrete surface, (iii borated water that has reacted with concrete, and (iv 2,400 ppm boric acid solutions with pH adjusted to a range of 6.0 to 7.7. The corrosion rates were measured using coupled multielectrode array sensor (CMAS and linear polarization resistance (LPR probes, both made using carbon steel. The results indicate that rebar corrosion rates are low (~1 μm/yr or lesswhen the solution pH is ~7.1 or higher. Below pH ~7.1, the corrosion rate increases with decreasing pH and can reach ~100 μm/yr in solutions with pH less than ~6.7. The threshold pH for carbon steel corrosion in borated solution is between 6.8 and 7.3.

  10. Development of Flow Accelerated Corrosion Reduction Technology

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Min Bum; Choi, Won Yeol; Lee, Jong Chan; Lim, Dong Seok; Kwon, Byung Il; Ku, Hee Kwon; Kim, Jong Uk [FNC Tech, Yongin (Korea, Republic of)

    2015-10-15

    Development of flow accelerated corrosion reduction technology is necessary for prevent this kind of accidents. This study deals with development of flow accelerated corrosion reduction technology through platinum injection and developed of flow accelerated corrosion reduction technology by imitating water chemical condition in PWR secondary system in practice. In addition, in order to get reliability of water chemical simulator in PWR secondary system, analyzed and compared with test result through CFD analysis. This study composed test device that can simulate water chemical environment in PWR secondary system, in order to develop flow accelerated corrosion reduction , and evaluated the ratio of corrosion in water chemical environment in PWR secondary system. In conclusion, corrosion ratio of low alloy steel material that includes more Cr and Mo was lower. And the results were confirmed to be the maximum corrosion rate in the case that replicate the 90 elbow. Additionally, inserted Pt nano particle for developing flow accelerated corrosion rate reduction technology, the test results, it was confirmed for about 80% of the flow accelerated corrosion rate reduction than before input.

  11. Corrosion Fatigue in District Heating Water Tanks

    DEFF Research Database (Denmark)

    Maahn, Ernst Emanuel

    1996-01-01

    Three candidate materials for construction of buffer tanks for district heating water have been tested for corrosion fatigue properties in a district heating water environment. The investigation included Slow Strain Rate Testing of plain tensile specimens, crack initiation testing by corrosion...... fatigue of plain tensile specimens and crack growth rate determination for Compact Tensile Specimens under corrosion fatigue conditions. The three materials are equal with respect to stress corrosion sensibility and crack initiation. Crack growth rate is increased with a factor of 4-6 relative to an inert...

  12. Corrosion problems in PWR steam generators

    International Nuclear Information System (INIS)

    Weber, J.; Suery, P.

    1976-01-01

    Examinations on pulled steam generator tubes from the Swiss nuclear power plants Beznau I and II, together with some laboratory tests, may be summarized as follows: Corrosion problems in vertical U-tube steam generators with Alloy 600 as tube material are localized towards relatively narrow regions above the tube sheet where thermohydraulic conditions and, as a consequence thereof, chemical conditions are uncontrolled. Within these zones Alloy 600 is not sufficienthy resistent to caustic or phosphate attack (caustic stress corrosion cracking and general corrosion, resp.). The mechanisms of several corrosion phenomena are not fully understood. (orig.) [de

  13. Fighting corrosion in air pollution control systems

    International Nuclear Information System (INIS)

    Rittenhouse, R.C.

    1991-01-01

    This paper reports that materials is the name of the game for corrosion prevention in air pollution control equipment. Whether the system is already in place, a retrofit, are specified for a new power pant, preventing corrosion is critical, because such deterioration easily undermines reliability. Hence, materials can heavily influence power plant compliance to the 1990 Clean Air Act amendments. Flue gas desulfurization (FGD) systems, perhaps the most vulnerable area to corrosion, are expected to be the method of choice for sulfur removal in many power plants in the near term. Components of these systems have various degrees of susceptibility to corrosion and related problems

  14. Emerging Corrosion Inhibitors for Interfacial Coating

    Directory of Open Access Journals (Sweden)

    Mona Taghavikish

    2017-12-01

    Full Text Available Corrosion is a deterioration of a metal due to reaction with environment. The use of corrosion inhibitors is one of the most effective ways of protecting metal surfaces against corrosion. Their effectiveness is related to the chemical composition, their molecular structures and affinities for adsorption on the metal surface. This review focuses on the potential of ionic liquid, polyionic liquid (PIL and graphene as promising corrosion inhibitors in emerging coatings due to their remarkable properties and various embedment or fabrication strategies. The review begins with a precise description of the synthesis, characterization and structure-property-performance relationship of such inhibitors for anti-corrosion coatings. It establishes a platform for the formation of new generation of PIL based coatings and shows that PIL corrosion inhibitors with various heteroatoms in different form can be employed for corrosion protection with higher barrier properties and protection of metal surface. However, such study is still in its infancy and there is significant scope to further develop new structures of PIL based corrosion inhibitors and coatings and study their behaviour in protection of metals. Besides, it is identified that the combination of ionic liquid, PIL and graphene could possibly contribute to the development of the ultimate corrosion inhibitor based coating.

  15. Corrosion behavior of 2205 duplex stainless steel.

    Science.gov (United States)

    Platt, J A; Guzman, A; Zuccari, A; Thornburg, D W; Rhodes, B F; Oshida, Y; Moore, B K

    1997-07-01

    The corrosion of 2205 duplex stainless steel was compared with that of AISI type 316L stainless steel. The 2205 stainless steel is a potential orthodontic bracket material with low nickel content (4 to 6 wt%), whereas the 316L stainless steel (nickel content: 10 to 14 wt%) is a currently used bracket material. Both stainless steels were subjected to electrochemical and immersion (crevice) corrosion tests in 37 degrees C, 0.9 wt% sodium chloride solution. Electrochemical testing indicates that 2205 has a longer passivation range than 316L. The corrosion rate of 2205 was 0.416 MPY (milli-inch per year), whereas 316L exhibited 0.647 MPY. When 2205 was coupled to 316L with equal surface area ratio, the corrosion rate of 2205 reduced to 0.260 MPY, indicating that 316L stainless steel behaved like a sacrificial anode. When 316L is coupled with NiTi, TMA, or stainless steel arch wire and was subjected to the immersion corrosion test, it was found that 316L suffered from crevice corrosion. On the other hand, 2205 stainless steel did not show any localized crevice corrosion, although the surface of 2205 was covered with corrosion products, formed when coupled to NiTi and stainless steel wires. This study indicates that considering corrosion resistance, 2205 duplex stainless steel is an improved alternative to 316L for orthodontic bracket fabrication when used in conjunction with titanium, its alloys, or stainless steel arch wires.

  16. Kinetics of steel corrosion in water

    International Nuclear Information System (INIS)

    Vettegren', V.I.; Bashkarev, A.Ya.; Danchukov, K.G.; Morozov, G.I.

    2003-01-01

    Kinetics of corrosion damage accumulation in steels of different composition (Cr-Ni-Mo-Ti, Cr-Ni-Mn-N-V, Cr-Ni-N-Mn-Mo, Cr-Ni-Nb, Cr-Ni-Ti, Cr-Mn-Ni, Mn-Al-Nb-Si, Mn-Cr-Al-Si and Mn-Al-Si) in NaCl solution and in sea water was studied. It is shown that degree of corrosion damage relates to time according to the first order reaction expression. The values of corrosion activation energy and of parameter characterizing protection properties of corrosion film are determined [ru

  17. Influence of corrosion layers on quantitative analysis

    International Nuclear Information System (INIS)

    Denker, A.; Bohne, W.; Opitz-Coutureau, J.; Rauschenberg, J.; Roehrich, J.; Strub, E.

    2005-01-01

    Art historians and restorers in charge of ancient metal objects are often reluctant to remove the corrosion layer evolved over time, as this would change the appearance of the artefact dramatically. Therefore, when an elemental analysis of the objects is required, this has to be done by penetrating the corrosion layer. In this work the influence of corrosion was studied on Chinese and Roman coins, where removal of oxidized material was possible. Measurements on spots with and without corrosion are presented and the results discussed

  18. Recent Corrosion Research Trends in Weld Joints

    International Nuclear Information System (INIS)

    Kim, Hwan Tae; Kil, Sang Cheol; Hwang, Woon Suk

    2007-01-01

    The increasing interest in the corrosion properties of weld joints in the corrosive environment is placing stringent demands on the manufacturing techniques and performance requirements, and the manufacture employs the high quality and efficiency welding process to produce welds. Welding plays an important role in the fabrication of chemical plants, nuclear power plant, ship construction, and this has led to an increasing attention to the corrosion resistant weld joints. This paper covers recent technical trends of welding technologies for corrosion resistance properties including the COMPENDEX DB analysis of welding materials, welding process, and welding fabrications

  19. Corrosion probe. Innovative technology summary report

    International Nuclear Information System (INIS)

    1999-05-01

    Over 253 million liters of high-level waste (HLW) generated from plutonium production is stored in mild steel tanks at the Department of Energy (DOE) Hanford Site. Corrosion monitoring of double-shell storage tanks (DSTs) is currently performed at Hanford using a combination of process knowledge and tank waste sampling and analysis. Available technologies for corrosion monitoring have progressed to a point where it is feasible to monitor and control corrosion by on-line monitoring of the corrosion process and direct addition of corrosion inhibitors. The electrochemical noise (EN) technique deploys EN-based corrosion monitoring probes into storage tanks. This system is specifically designed to measure corrosion rates and detect changes in waste chemistry that trigger the onset of pitting and cracking. These on-line probes can determine whether additional corrosion inhibitor is required and, if so, provide information on an effective end point to the corrosion inhibitor addition procedure. This report describes the technology, its performance, its application, costs, regulatory and policy issues, and lessons learned

  20. Corrosion of steel structures in sea-bed sediment

    Indian Academy of Sciences (India)

    Unknown

    corrosion mechanism, measurement of metal corrosion rate, corrosion ... cables, steel rigs, pipelines and other marine facilities, is ..... make high strength steel material to crack with stress ... of SBS has yet been very limited, and selection of.

  1. corrosion response of low carbon steel in tropical road mud

    African Journals Online (AJOL)

    Dr Obe

    Corrosion Mitigation efforts using readily available anti- corrosion coatings to protect low carbon steel test coupons against the ... The following protective coating devices were effective: ..... 2 West, J.M (1986): Basic Corrosion and Oxidation,.

  2. Propagation of steel corrosion in concrete: Experimental and numerical investigations

    DEFF Research Database (Denmark)

    Michel, Alexander; Otieno, M.; Stang, Henrik

    2016-01-01

    This paper focuses on experimental and numerical investigations of the propagation phase of reinforcement corrosion to determine anodic and cathodic Tafel constants and exchange current densities, from corrosion current density and corrosion potential measurements. The experimental program includ...

  3. Analysis of corrosive environmental factors of seabed sediment

    Indian Academy of Sciences (India)

    Unknown

    Seabed sediment; corrosion; environmental factors. 1. Introduction. The corrosion ... plays an important role in the corrosion behaviour of steel in sediment. Figure 2b shows the change in oxidation-reduction po- tential, Eh with distance from ...

  4. Corrosion problems and solutions in oil refining and petrochemical industry

    CERN Document Server

    Groysman, Alec

    2017-01-01

    This book addresses corrosion problems and their solutions at facilities in the oil refining and petrochemical industry, including cooling water and boiler feed water units. Further, it describes and analyzes corrosion control actions, corrosion monitoring, and corrosion management. Corrosion problems are a perennial issue in the oil refining and petrochemical industry, as they lead to a deterioration of the functional properties of metallic equipment and harm the environment – both of which need to be protected for the sake of current and future generations. Accordingly, this book examines and analyzes typical and atypical corrosion failure cases and their prevention at refineries and petrochemical facilities, including problems with: pipelines, tanks, furnaces, distillation columns, absorbers, heat exchangers, and pumps. In addition, it describes naphthenic acid corrosion, stress corrosion cracking, hydrogen damages, sulfidic corrosion, microbiologically induced corrosion, erosion-corrosion, and corrosion...

  5. Corrosion process studies in a nuclear waste container

    International Nuclear Information System (INIS)

    Guasp, Ruben A.; Lanzani, Liliana A.; Coronel, Pascual; Bruzzoni, Pablo; Semino, Carlos J.

    1999-01-01

    Latest results on corrosion behavior studies on high activity nuclear waste container are reported. Corrosion evaluation on lead base alloys and modeling to predict carbon steel external container cover generalized corrosion, are the main issues of these studies. (author)

  6. Assessing Level and Effectiveness of Corrosion Education in the UAE

    OpenAIRE

    Lim, Hwee Ling

    2012-01-01

    The consequences of corrosion can be minimized by an engineering workforce well trained in corrosion fundamentals and management. Since the United Arab Emirates incurs the second highest cost of corrosion after Saudi Arabia, this paper examined the quality of corrosion education in the UAE. Surveys with academia and industry respondents showed that dedicated corrosion courses and engineering courses that integrated corrosion into the curricula were available in UAE universities, but graduates...

  7. Events as Power Source: Wireless Sustainable Corrosion Monitoring

    OpenAIRE

    Sun, Guodong; Qiao, Guofu; Zhao, Lin; Chen, Zhibo

    2013-01-01

    This study presents and implements a corrosion-monitoring wireless sensor platform, EPS (Events as Power Source), which monitors the corrosion events in reinforced concrete (RC) structures, while being powered by the micro-energy released from the corrosion process. In EPS, the proposed corrosion-sensing device serves both as the signal source for identifying corrosion and as the power source for driving the sensor mote, because the corrosion process (event) releases electric energy; this is ...

  8. Corrosion test by low-temperature coal tar

    Energy Technology Data Exchange (ETDEWEB)

    Ando, S; Yamamoto, S

    1952-01-01

    Corrosive actions of various fractions of low-temperature coal tar against mild steel or Cr 13-steel were compared at their boiling states. Corrosions became severe when the boiling points exceeded 240/sup 0/. The acidic fractions were more corrosive. In all instances, corrosion was excessive at the beginning of immersion testing and then gradually became mild; boiling accelerated the corrosion. Cr 13-steel was corrosion-resistant to low-temperature coal-tar fractions.

  9. Corrosion '98: 53. annual conference and exposition, proceedings

    International Nuclear Information System (INIS)

    Anon.

    1998-01-01

    This conference was divided into the following sections: Corrosion in Gas Treating; Problems and Solutions in Commercial Building Water Systems; Green Corrosion/Scale Inhibitors; Atmospheric Corrosion; AIRPOL Update/98; Rubber Lining--Answers to Many Problems; Interference Problems; Environmental Assisted Cracking: Fundamental Research and Industrial Applications; Corrosion in Nuclear Systems; New Developments in Scale and Deposit Control; Corrosion and Corrosion Protection in the Transportation Industries; What's All the Noise About--Electrochemical That Is; Refining Industry Corrosion; Corrosion Problems in Military Hardware: Case Histories, Fixes and Lessons Learned; Cathodic Protection Test Methods and Instrumentation for Underground and On-grade Pipelines and Tanks; Recent Developments in Volatile Corrosion Inhibitors; Corrosion in Supercritical Fluids; Microbiologically Influenced Corrosion; Advances in Understanding and Controlling CO 2 Corrosion; Managing Corrosion with Plastics; Material Developments for Use in Exploration and Production Environments; Corrosion in Cold Regions; The Effect of Downsizing and Outsourcing on Cooling System Monitoring and Control Practices; New Developments in Mechanical and Chemical Industrial Cleaning; Mineral Scale Deposit Control in Oilfield Related Operations; Biocides in Cooling Water; Corrosion and Corrosion Control of Reinforced Concrete Structures; Materials Performance for Fossil Energy Conversion Systems; Marine corrosion; Thermal Spray--Coating and Corrosion Control; Flow Effects on Corrosion in Oil and Gas Production; Corrosion Measurement Technologies; Internal Pipeline Monitoring--Corrosion Monitoring, Intelligent Pigging and Leak Detection; Cathodic Protection in Natural Waters; Corrosion in Radioactive Liquid Waste Systems; On-line Hydrogen Permeation Monitoring Equipment and Techniques, State of the Art; Water Reuse and Recovery; Performance of Materials in High Temperature Environments; Advances in Motor

  10. Effets Seebeck et Nernst dans les cuprates: Etude de la reconstruction de la surface de Fermi sous champ magnetique intense

    Science.gov (United States)

    Laliberte, Francis

    2010-06-01

    Ce memoire presente des mesures de transport thermoelectrique, les effets Seebeck et Nernst, dans une serie d'echantillons de supraconducteurs a haute temperature critique. Des resultats obtenus recemment au Laboratoire National des Champs Magnetiques Intenses a Grenoble sur La1.7Eu0.2Sr0.1 CuO4, La1.675Eu0.2Sr0.125CuO 4, La1.64Eu0.2Sr0.16CuO4, La1.74Eu0.1Sr0.16CuO4 et La 1.4Nd0.4Sr0.2CuO4 sont analyses. Une attention particuliere est accordee aux equations de la theorie semi-classique du transport et leur validite est verifiee. La procedure experimentale et les materiaux utilises pour concevoir les montages de mesures sont expliques en detail. Enfin, un chapitre est dedie a l'explication et l'interpretation des resultats de transport thermoelectrique sur YBa2Cu3O6+delta publies au cours de l'hiver 2010 dans les revues Nature et Physical Review Letters. Les donnees d'effet Seebeck dans les echantillons de La 1.8-x,Eu0.2SrxCuO 4, ou un changement de signe est observe, permettent de conclure a la presence d'une poche d'electrons dans la surface de Fermi qui domine le transport a basse temperature dans la region sous-dopee du diagramme de phase. Cette conclusion est similaire a celle obtenue par des mesures d'effet Hall dans YBa 2Cu3O6+delta et elle cadre bien dans un scenario de reconstruction de la surface de Fermi. Les donnees d'effet Nernst recueillies indiquent que la contribution des fluctuations supraconductrices est limitee a un modeste intervalle de temperature au-dessus de la temperature critique.

  11. Developpement d'un modele analytique pour l'analyse en elasticite lineaire de champs de deformation et contrainte au sein d'un polycristal. comparaison avec la methode des elements finis =

    Science.gov (United States)

    Bretin, Remy

    L'endommagement par fatigue des materiaux est un probleme courant dans de nombreux domaines, dont celui de l'aeronautique. Afin de prevenir la rupture par fatigue des materiaux il est necessaire de determiner leur duree de vie en fatigue. Malheureusement, dues aux nombreuses heterogeneites presentes, la duree de vie en fatigue peut fortement varier entre deux pieces identiques faites dans le meme materiau ayant subi les memes traitements. Il est donc necessaire de considerer ces heterogeneites dans nos modeles afin d'avoir une meilleure estimation de la duree de vie des materiaux. Comme premiere etape vers une meilleure consideration des heterogeneites dans nos modeles, une etude en elasticite lineaire de l'influence des orientations cristallographiques sur les champs de deformations et de contraintes dans un polycristal a ete realisee a l'aide de la methode des elements finis. Des correlations ont pu etre etablies a partir des resultats obtenus, et un modele analytique en elasticite lineaire prenant en compte les distributions d'orientations cristallographiques et les effets de voisinage a pu etre developpe. Ce modele repose sur les bases des modeles d'homogeneisation classique, comme le schema auto-coherent, et reprend aussi les principes de voisinage des automates cellulaires. En prenant pour reference les resultats des analyses elements finis, le modele analytique ici developpe a montre avoir une precision deux fois plus grande que le modele auto-coherent, quel que soit le materiau etudie.

  12. La pollution des sols des champs d’épandage d’eaux usées, contrainte et/ou ressource pour le développement durable en plaine de Bessancourt-Herblay-Pierrelaye

    Directory of Open Access Journals (Sweden)

    Vincent Mandinaud

    2005-11-01

    Full Text Available Historiquement affectés à l’assainissement des eaux usées brutes et à l’amendement des sols, les champs d’épandage de la ville de Paris, puis du SIAAP, sont au début de l’année 1997 en passe d’être publiquement reconnus pollués par des Eléments Traces Métalliques (ETM . Différentes opérations participent de ce double processus de reconsidération des risques associés à l’épandage et de requalification des entités territoriales concernées. La présentation dynamique des prises et des contraintes développées, en plaine de Bessancourt-Herblay-Pierrelaye singulièrement, permet de montrer comment la pollution des sols peut (réactiver localement une réflexion collective sur un développement territorial durable.

  13. NASA's Corrosion Technology Laboratory at the Kennedy Space Center: Anticipating, Managing, and Preventing Corrosion

    Science.gov (United States)

    Calle, Luz Marina

    2014-01-01

    Corrosion is the degradation of a material that results from its interaction with the environment. The marine environment at NASAs Kennedy Space Center (KSC) has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the United States. With the introduction of the Space Shuttle in 1981, the already highly corrosive conditions at the launch pads were rendered even more severe by the 70 tons of highly corrosive hydrochloric acid that were generated by the solid rocket boosters. Numerous failures at the launch pads are caused by corrosion.The structural integrity of ground infrastructure and flight hardware is critical to the success, safety, cost, and sustainability of space missions. As a result of fifty years of experience with launch and ground operations in a natural marine environment that is highly corrosive, NASAs Corrosion Technology Laboratory at KSC is a major source of corrosion control expertise in the launch and other environments. Throughout its history, the Laboratory has evolved from what started as an atmospheric exposure facility near NASAs launch pads into a world-wide recognized capability that provides technical innovations and engineering services in all areas of corrosion for NASA and external customers.This presentation will provide a historical overview of the role of NASAs Corrosion Technology in anticipating, managing, and preventing corrosion. One important challenge in managing and preventing corrosion involves the detrimental impact on humans and the environment of what have been very effective corrosion control strategies. This challenge has motivated the development of new corrosion control technologies that are more effective and environmentally friendly. Strategies for improved corrosion protection and durability can have a huge impact on the economic sustainability of human spaceflight operations.

  14. Environmental Friendly Coatings and Corrosion Prevention For Flight Hardware Project

    Science.gov (United States)

    Calle, Luz

    2014-01-01

    Identify, test and develop qualification criteria for environmentally friendly corrosion protective coatings and corrosion preventative compounds (CPC's) for flight hardware an ground support equipment.

  15. Materials corrosion and protection at high temperatures

    International Nuclear Information System (INIS)

    Balbaud, F.; Desgranges, Clara; Martinelli, Laure; Rouillard, Fabien; Duhamel, Cecile; Marchetti, Loic; Perrin, Stephane; Molins, Regine; Chevalier, S.; Heintz, O.; David, N.; Fiorani, J.M.; Vilasi, M.; Wouters, Y.; Galerie, A.; Mangelinck, D.; Viguier, B.; Monceau, D.; Soustelle, M.; Pijolat, M.; Favergeon, J.; Brancherie, D.; Moulin, G.; Dawi, K.; Wolski, K.; Barnier, V.; Rebillat, F.; Lavigne, O.; Brossard, J.M.; Ropital, F.; Mougin, J.

    2011-01-01

    This book was made from the lectures given in 2010 at the thematic school on 'materials corrosion and protection at high temperatures'. It gathers the contributions from scientists and engineers coming from various communities and presents a state-of-the-art of the scientific and technological developments concerning the behaviour of materials at high temperature, in aggressive environments and in various domains (aerospace, nuclear, energy valorization, and chemical industries). It supplies pedagogical tools to grasp high temperature corrosion thanks to the understanding of oxidation mechanisms. It proposes some protection solutions for materials and structures. Content: 1 - corrosion costs; macro-economical and metallurgical approach; 2 - basic concepts of thermo-chemistry; 3 - introduction to the Calphad (calculation of phase diagrams) method; 4 - use of the thermodynamic tool: application to pack-cementation; 5 - elements of crystallography and of real solids description; 6 - diffusion in solids; 7 - notions of mechanics inside crystals; 8 - high temperature corrosion: phenomena, models, simulations; 9 - pseudo-stationary regime in heterogeneous kinetics; 10 - nucleation, growth and kinetic models; 11 - test experiments in heterogeneous kinetics; 12 - mechanical aspects of metal/oxide systems; 13 - coupling phenomena in high temperature oxidation; 14 - other corrosion types; 15 - methods of oxidized surfaces analysis at micro- and nano-scales; 16 - use of SIMS in the study of high temperature corrosion of metals and alloys; 17 - oxidation of ceramics and of ceramic matrix composite materials; 18 - protective coatings against corrosion and oxidation; 19 - high temperature corrosion in the 4. generation of nuclear reactor systems; 20 - heat exchangers corrosion in municipal waste energy valorization facilities; 21 - high temperature corrosion in oil refining and petrochemistry; 22 - high temperature corrosion in new energies industry. (J.S.)

  16. Corrosion potential monitoring in nuclear power environments

    International Nuclear Information System (INIS)

    Molander, A.

    2004-01-01

    Full text of publication follows: corrosion monitoring. The corrosion potential is usually an important parameter or even the prime parameter for many types of corrosion processes. One typical example of the strong influence of the corrosion potential on corrosion performance is stress corrosion of sensitized stainless steel in pure high temperature water corresponding to boiling water conditions. The use of in-plant monitoring to follow the effect of hydrogen addition to mitigate stress corrosion in boiling water reactors is now a well-established technique. However, different relations between the corrosion potential of stainless steel and the oxidant concentration have been published and only recently an improved understanding of the electrochemical reactions and other conditions that determine the corrosion potential in BWR systems have been reached. This improved knowledge will be reviewed in this paper. Electrochemical measurements has also been performed in PWR systems and mainly the feedwater system on the secondary side of PWRs. The measurements performed so far have shown that electrochemical measurements are a very sensitive tool to detect and follow oxygen transients in the feedwater system. Also determinations of the minimum hydrazine dosage to the feedwater have been performed. However, PWR secondary side monitoring has not yet been utilized to the same level as BWR hydrogen water chemistry surveillance. The future potential of corrosion potential monitoring will be discussed. Electrochemical measurements are also performed in other reactor systems and in other types of reactors. Experiences will be briefly reviewed. In a BWR on hydrogen water chemistry and in the PWR secondary system the corrosion potentials show a large variation between different system parts. To postulate the material behavior at different locations the local chemical and electrochemical conditions must be known. Thus, modeling of chemical and electrochemical conditions along

  17. Screening of soil corrosivity by field testing: Results and design of an electrochemical soil corrosion probe

    DEFF Research Database (Denmark)

    Nielsen, Lars vendelbo; Bruun, Niels Kåre

    1996-01-01

    The corrosivity of different types of soil have been assessed by exposing carbon-steel plates at 50 different locations in Denmark for an extended period of time. The investigations included weight loss measurements and analysis of the chemical compositions of the corrosion products formed...... on the plates during exposure. An electrochemical soil corrosion probe has been designed and manufactured allowing for simultaneous measurements of several qauntities to predict corrosion. The probe consists of individual sections capable of measuring redox-potential, corrosion potential, soil resistivity...

  18. High Temperature Corrosion under Laboratory Conditions Simulating Biomass-Firing: A Comprehensive Characterization of Corrosion Products

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi; Montgomery, Melanie; Jappe Frandsen, Flemming

    2014-01-01

    characterization of the corrosion products. The corrosion products consisted of three layers: i) the outermost layer consisting of a mixed layer of K2SO4 and FexOy on a partly molten layer of the initial deposit, ii) the middle layer consists of spinel (FeCr2O4) and Fe2O3, and iii) the innermost layer is a sponge......-like Ni3S2 containing layer. At the corrosion front, Cl-rich protrusions were observed. Results indicate that selective corrosion of Fe and Cr by Cl, active oxidation and sulphidation attack of Ni are possible corrosion mechanisms....

  19. Effect of Flow Velocity on Corrosion Rate and Corrosion Protection Current of Marine Material

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seong Jong [Kunsan National University, Kunsan (Korea, Republic of); Han, Min Su; Jang, Seok Ki; Kim, Seong Jong [Mokpo National Maritime University, Mokpo (Korea, Republic of)

    2015-10-15

    In spite of highly advanced paint coating techniques, corrosion damage of marine metal and alloys increase more and more due to inherent micro-cracks and porosities in coatings formed during the coating process. Furthermore, flowing seawater conditions promote the breakdown of the protective oxide of the materials introducing more oxygen into marine environments, leading to the acceleration of corrosion. Various corrosion protection methods are available to prevent steel from marine corrosion. Cathodic protection is one of the useful corrosion protection methods by which the potential of the corroded metal is intentionally lowered to an immune state having the advantage of providing additional protection barriers to steel exposed to aqueous corrosion or soil corrosion, in addition to the coating. In the present investigation, the effect of flow velocity was examined for the determination of the optimum corrosion protection current density in cathodic protection as well as the corrosion rate of the steel. It is demonstrated from the result that the material corrosion under dynamic flowing conditions seems more prone to corrosion than under static conditions.

  20. The Effects of Corrosive Chemicals on Corrosion Rate of Steel Reinforcement Bars: II. Swamp Sludges

    Directory of Open Access Journals (Sweden)

    Henki Ashadi

    2010-10-01

    Full Text Available A polluted environment will influence the building age. The objective of this research was to find out the influence of corrosive chemicals within the sludge swamp area with the corrosion rate of steel concrete. Corrosion in steel concrete usually occur in acid area which contain of SO42-, Cl- and NO3-. The research treatment used by emerging ST 37 andST 60 within 60 days in 'polluted' sludge swamp area. Three variation of 'polluted' swamp sludge were made by increasing the concentration a corrosive unsure up to 1X, 5X and 10X. The corrosion rate measured by using an Immersion Method. The result of Immersion test showed that sulphate had a greatest influence to corrosion rate of ST 37 and ST 60 and followed by chloride and nitrate. Corrosion rate value for ST 37 was 17.58 mpy and for ST 60 was 12.47 mpy.

  1. General Corrosion and Localized Corrosion of the Drip Shield

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua; K. Mon

    2003-06-24

    The recommended waste package (WP) design is described in BSC (2001a). The design includes a double-wall WP underneath a protective drip shield (DS) (BSC 2003a). The purpose of the process-level models developed in this report is to model dry oxidation (DOX), general corrosion (GC) and localized corrosion (LC) of the DS plate material, which is made of Ti Grade 7. The DS design also includes structural supports fabricated from Ti Grade 24. Degradation of Ti Grade 24 is not considered in this report. The DS provides protection for the waste package outer barrier (WPOB) both as a barrier to seepage water contact and a physical barrier to potential rockfall. This Model Report (MR) serves as a feed to the Integrated Waste Package Degradation Model (IWPD) analyses, and was developed in accordance with the Technical Work Plan (TWP) (BSC 2002a). The models contained in this report serve as a basis to determine whether or not the performance requirements for the DS can be met.

  2. General Corrosion and Localized Corrosion of the Drip Shield

    International Nuclear Information System (INIS)

    Hua, F.; Mon, K.

    2003-01-01

    The recommended waste package (WP) design is described in BSC (2001a). The design includes a double-wall WP underneath a protective drip shield (DS) (BSC 2003a). The purpose of the process-level models developed in this report is to model dry oxidation (DOX), general corrosion (GC) and localized corrosion (LC) of the DS plate material, which is made of Ti Grade 7. The DS design also includes structural supports fabricated from Ti Grade 24. Degradation of Ti Grade 24 is not considered in this report. The DS provides protection for the waste package outer barrier (WPOB) both as a barrier to seepage water contact and a physical barrier to potential rockfall. This Model Report (MR) serves as a feed to the Integrated Waste Package Degradation Model (IWPD) analyses, and was developed in accordance with the Technical Work Plan (TWP) (BSC 2002a). The models contained in this report serve as a basis to determine whether or not the performance requirements for the DS can be met

  3. Silicate glasses corrosion. Texture analysis of the corrosion layer

    International Nuclear Information System (INIS)

    Portal, Sabine

    2001-01-01

    We have studied the kinetic and the texture evolution of the corroded layer that forms on glass surfaces exposed to acidic solutions. The corroded layer is depleted in alkali cations and is produced by an ion exchange mechanism. It is porous and shows a lower refractive index than the one of the bulk glass. Spectroscopic ellipsometry allows determining the thickness of the layer and its refractive index. Several other techniques have been developed for characterizing the corrosion behaviour of glass surfaces: porosity is thus investigated by adsorption-desorption of nitrogen; the thickness and the composition of the layer are studied by secondary ion mass spectroscopy (S.I.M.S.); sodium concentration in the solution has been analyzed by atomic absorption. This study shows the importance of leaching conditions and glass preparation. The type of drying employed is susceptible to modify the texture and the structure of the layer. The layers produced in the early stages of the leaching process are not easily detectable. The different results lead however to the same conclusion: after a strong increase of porosity, a densification of the layer is observed with increasing time. The evolution of the layer texture could therefore modify the kinetic of the glass corrosion. (author) [fr

  4. Corrosion protected reversing heat exchanger

    International Nuclear Information System (INIS)

    Zawierucha, R.

    1984-01-01

    A reversing heat exchanger of the plate and fin type having multiple aluminum parting sheets in a stacked arrangement with corrugated fins separating the sheets to form multiple flow paths, means for closing the ends of the sheets, an input manifold arrangement of headers for the warm end of of the exchanger and an output manifold arrangement for the cold end of the exchanger with the input air feed stream header and the waste gas exhaust header having an alloy of zinc and aluminum coated on the inside surface for providing corrosion protection to the stack

  5. Galvanic corrosion in odontological alloys

    International Nuclear Information System (INIS)

    Riesgo, O.; Bianchi, G.L.; Duffo, G.S.

    1993-01-01

    Galvanic corrosion can occur when different alloys are placed in direct contact within the oral cavity or within tissues. Concern has been expressed associated with the coupling of selected restorative materials as well as implant material with various alloys used for restorative procedures. This could be critical if the crown or bridge had subgingival finish line with a metallic zone in contact with the tissue, and the implant was made in titanium alloy. The present work shows the results of galvanic coupling studies done on implants of titanium alloy connected to nickel-chromium and cobalt-chromium alloys. (Author)

  6. Corrosion Chemistry in Inhibited HDA.

    Science.gov (United States)

    1980-11-30

    which are likely to resemble authentic Modified HDA corrosion products, and reactions of a range of metal fluorides with difluorphosphoric acid have i...Introduction 10 (b) Solutions of HF in nitric acid and in HDA 10 (c) Solutions of PF5 in HDA 10 (d) Solutions of HPO 2 F2 in HDA 15 (e) Solutions of...of metals with HPO F in HDA 2 2 solution. 166 Iron. 166 Nickel. 166 (c) Reactions of metal fluorides with difluorophosphoric acid . 169 B-FeF 3.3H 2 0

  7. [Microbiological corrosion of aluminum alloys].

    Science.gov (United States)

    Smirnov, V F; Belov, D V; Sokolova, T N; Kuzina, O V; Kartashov, V R

    2008-01-01

    Biological corrosion of ADO quality aluminum and aluminum-based construction materials (alloys V65, D16, and D16T) was studied. Thirteen microscopic fungus species and six bacterial species proved to be able to attack aluminum and its alloys. It was found that biocorrosion of metals by microscopic fungi and bacteria was mediated by certain exometabolites. Experiments on biocorrosion of the materials by the microscopic fungus Alternaria alternata, the most active biodegrader, demonstrated that the micromycete attack started with the appearance of exudate with pH 8-9 on end faces of the samples.

  8. Corrosion effects on soda lime glass

    NARCIS (Netherlands)

    Veer, F.A.; Rodichev, Y.M.

    2010-01-01

    Although soda lime glass is the most common used transparent material in architecture, little is known about the corrosion effects on long term strength and the interaction between corrosion and defects. Extensive testing on soda lime bars under different environmental conditions and different

  9. Computer-Aided Corrosion Program Management

    Science.gov (United States)

    MacDowell, Louis

    2010-01-01

    This viewgraph presentation reviews Computer-Aided Corrosion Program Management at John F. Kennedy Space Center. The contents include: 1) Corrosion at the Kennedy Space Center (KSC); 2) Requirements and Objectives; 3) Program Description, Background and History; 4) Approach and Implementation; 5) Challenges; 6) Lessons Learned; 7) Successes and Benefits; and 8) Summary and Conclusions.

  10. Drywell corrosion stopped at Oyster Creek

    International Nuclear Information System (INIS)

    Lipford, B.L.; Flynn, J.C.

    1993-01-01

    This article describes the detection of corrosion on the drywell containment vessel of Oyster Creek Nuclear Plant and the application of a protective coating to repair the drywell. The topics of the article include drywell design features, identification of the problem, initial action, drywell corrosion, failure of cathodic protection, long-term repair, and repair results

  11. A Course in Electrochemical and Corrosion Engineering.

    Science.gov (United States)

    Van Zee, John

    1985-01-01

    Describes a course designed to show similarities between electrochemistry and corrosion engineering and to show graduate students that electrochemical and corrosion engineering can be accomplished by extending their knowledge of chemical engineering models. Includes course outline, textbooks selected, and teaching methods used. (JN)

  12. Dissolution properties of cerium dibutylphosphate corrosion inhibitors

    NARCIS (Netherlands)

    Soestbergen, van M.; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

    2013-01-01

    The corrosion inhibitor cerium dibutylphosphate, Ce(dbp)3, prevents corrosion by cerium and dbp deposition at the alkaline cathode and acidic anode respectively. The pH dependent Ce(dbp)3 solubility seems to play an essential role in the inhibition degree. We found that Ce(dbp)3 scarcely dissolves

  13. Corrosion and compatibility in liquid alkali metals

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The literature dealing with liquid alkali metal corrosion of vanadium and its alloys is reviewed in the following subsections. Attention is given to both lithium and sodium data. Preceding this review, a brief outline of the current state of understanding of liquid metal corrosion mechanisms is provided

  14. EXTRACT OF COMBRETUM MICRANTHUM AS CORROSION ...

    African Journals Online (AJOL)

    user

    2016-10-04

    Oct 4, 2016 ... methanol extract CM is a good adsorption inhibitor for the corrosion of Al-Si-Mg in 3.5wt% NaCl solution. Tafel polarization analysis indicates that the studied plant extract is a mixed ..... (2008). [2] Shreir, L. L., Jarman, R. A. and Burstein, G. T.. Corrosion ... [6] Maqsood Ahmad Malik, Mohammad Ali Hashim,.

  15. Modeling of Corrosion-induced Concrete Damage

    DEFF Research Database (Denmark)

    Thybo, Anna Emilie A.; Michel, Alexander; Stang, Henrik

    2013-01-01

    In the present paper a finite element model is introduced to simulate corrosion-induced damage in concrete. The model takes into account the penetration of corrosion products into the concrete as well as non-uniform formation of corrosion products around the reinforcement. To ac-count for the non...... of corrosion products affects both the time-to cover cracking and the crack width at the concrete surface.......In the present paper a finite element model is introduced to simulate corrosion-induced damage in concrete. The model takes into account the penetration of corrosion products into the concrete as well as non-uniform formation of corrosion products around the reinforcement. To ac-count for the non......-uniform formation of corrosion products at the concrete/reinforcement interface, a deterministic approach is used. The model gives good estimates of both deformations in the con-crete/reinforcement interface and crack width when compared to experimental data. Further, it is shown that non-uniform deposition...

  16. Microbiologically influenced corrosion in ship ballast tanks

    NARCIS (Netherlands)

    Heyer, A.

    2013-01-01

    Microbiologically influenced corrosion (MIC) is known to be a dangerous process in ship tanks due to its rapid and yet unpredictable occurrence, leading to extremely fast local corrosion, possibly jeopardizing the structural integrity, in a relatively short time. This project focuses on a

  17. 49 CFR 193.2625 - Corrosion protection.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Corrosion protection. 193.2625 Section 193.2625 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...: FEDERAL SAFETY STANDARDS Maintenance § 193.2625 Corrosion protection. (a) Each operator shall determine...

  18. Corrosion problems in nuclear power industry

    International Nuclear Information System (INIS)

    Flis, J.; Janik-Czachor, M.

    1980-01-01

    Characteristics were given of steels and alloys used in the PWR nuclear power plants and of water used in the primary and secondary systems. Corrosion damages of materials and installations were described. It was indicated that the damages were due mainly to stress corrosion cracking. Main preventive methods were listed. (author)

  19. Corrosion mechanism of copper in palm biodiesel

    International Nuclear Information System (INIS)

    Fazal, M.A.; Haseeb, A.S.M.A.; Masjuki, H.H.

    2013-01-01

    Highlights: ► Corrosion of copper in biodiesel increases with the increase of immersion time. ► The corrosion patina is found to be composed of CuO, Cu 2 O, CuCO 3 and Cu(OH) 2 . ► Green CuCO 3 was found as the major corrosion product. ► The mechanisms governing corrosion of copper in palm biodiesel are discussed. - Abstract: Biodiesel is a promising alternative fuel. However, it causes enhanced corrosion of automotive materials, especially of copper based components. In the present study, corrosion mechanism of copper was investigated by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Compositional change of biodiesel due to the exposure of copper was also investigated. Corrosion patina on copper is found to be composed of Cu 2 O, CuO, Cu(OH) 2 and CuCO 3. Dissolved O 2 , H 2 O, CO 2 and RCOO − radical in biodiesel seem to be the leading factors in enhancing the corrosiveness of biodiesel.

  20. Downhole corrosion mechanisms and mitigation strategies

    Energy Technology Data Exchange (ETDEWEB)

    McDougall, D. [Baker Hughes Canada, Calgary, AB (Canada)

    2010-07-01

    Pipeline corrosion refers to its deterioration because of a reaction with its environment. Although the physical condition of the metal at the anode initiates the corrosion process, it is the chemistry and composition of the electrolyte that controls the rate of the corrosion reaction and the severity of the corrosion. This presentation described the role of corrosion rate accelerators, with particular reference to dissolved gases such as oxygen, hydrogen sulfides and carbon dioxide, as well as pH levels, salinity, flow rate, temperature and presence of solids such as iron sulfides and sulfur. The effects of these accelerators were shown to be additive. Mitigation strategies include using materials such as resistant metal alloys or fiberglass, and applying coatings and chemical inhibitors. The importance of corrosion monitoring was also emphasized, with particular reference to the value of examining the number of corrosion related failures that have occurred over a fixed period of time. It was concluded that the ability to analyze samples of failed materials results in a better understanding of the cause of the failure, and is an integral part of designing any successful corrosion control program. tabs., figs.

  1. A South African corrosion research contribution

    International Nuclear Information System (INIS)

    Robinson, F.P.A.

    1980-01-01

    This paper contains the historical background to the setting up of the S.A. Corrosion Institute. The Metallurgy Department of the University of the Witwatersrand has been a training ground for corrosion scientists and engineers. Most of the research and development carried out has been devoted to stainless steels and more particularly to studying the effects of different alloying elements

  2. Localized corrosion problems in water reactors

    International Nuclear Information System (INIS)

    Coriou, Henri.

    1977-01-01

    Main localized etching on the structure materials of water reactors are studied: stress corrosion on stainless steel 304 (B.W.R), stress corrosion, 'wall thinning' and denting of Inconel 600 vapor generator tubes (P.W.R.). Some mechanisms are examined and practical exemples in reactors are described. Various possible cures are presented [fr

  3. Internal Corrosion Detection in Liquids Pipelines

    Science.gov (United States)

    2012-01-01

    PHMSA project DTRS56-05-T-0005 "Development of ICDA for Liquid Petroleum Pipelines" led to the development of a Direct Assessment (DA) protocol to prioritize locations of possible internal corrosion. The underlying basis LP-ICDA is simple; corrosion ...

  4. Bridging of inspection with corrosion management

    International Nuclear Information System (INIS)

    Zamaluddin Ali; Mohd Hawari Hassan; Rohana Jaafar

    2009-01-01

    Formerly, Inspection and Corrosion Engineers have less interaction and sharing of information to each other even they are working in the same plant or organization. Inspection finding either from visual inspection or NDT techniques rarely shared with corrosion engineers. Similarly corrosion engineers rarely discussed their corrosion prediction and potential damage mechanism with inspection engineers. A demanding request of more holistic plant safety and asset integrity promoted the introduction and implementation of Risk Based Inspection (RBI). RBI analysis demands the input mainly from both disciplines i.e. Inspection and Corrosion Engineers. Most of RBI methodologies are once-off analysis approach which also promoted once-off interaction between Inspection and Corrosion Engineers. PETRONAS has developed a methodology with supporting software, integrating both Inspection and Corrosion disciplines. PETRONAS Risk Based Inspection (PRBI) is intended to promote continuous integration of Inspection and Corrosion management of the plant through out the whole life cycle starting from the design stage to fabrication, operation and decommissions stage. (author)

  5. The dual role of microbes in corrosion

    NARCIS (Netherlands)

    Kip, D.J.; Van Veen, J.A.

    2015-01-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced

  6. Glove corrosive liquid immersion and permeability study

    International Nuclear Information System (INIS)

    Middleton, H.W.

    1977-01-01

    The Occupational Safety and Health Administration's requirement for protective equipment for personnel working with chemical hazards resulted in a study of gloves used in work with corrosive liquids. Gloves of different materials and weights were tested using ASTM methods, in various corrosive liquids. Results show the best material for gloves used for different lengths of time in the liquids

  7. The corrosion behavior of DWPF glasses

    International Nuclear Information System (INIS)

    Ebert, W.L.; Bates, J.K.

    1995-01-01

    The authors analyzed the corroded surfaces of reference glasses developed for the Defense Waste Processing Facility (DWPF) to characterize their corrosion behavior. The corrosion mechanism of nuclear waste glasses must be known in order to provide source terms describing radionuclide release for performance assessment calculations. Different DWPF reference glasses were corroded under conditions that highlighted various aspects of the corrosion process and led to different extents of corrosion. The glasses corroded by similar mechanisms, and a phenomenological description of their corrosion behavior is presented here. The initial leaching of soluble glass components results in the formation of an amorphous gel layer on the glass surface. The gel layer is a transient phase that transforms into a layer of clay crystallites, which equilibrates with the solution as corrosion continues. The clay layer does not act as a barrier to either water penetration or glass dissolution, which continues beneath it, and may eventually separate from the glass. Solubility limits for glass components may be established by the eventual precipitation of secondary phases; thus, corrosion of the glass becomes controlled by the chemical equilibrium between the solution and the assemblage of secondary phases. In effect, the solution is an intermediate phase through which the glass transforms to an energetically more favorable assemblage of phases. Implications regarding the prediction of long-term glass corrosion behavior are discussed

  8. INVESTIGATIONS ON THE CORROSION OF CONSTRUCTIONAL ...

    African Journals Online (AJOL)

    BCSE

    The corrosion behavior of three constructional steels used in Senegal, S235, .... the attack is deep and the pits propagate in depth with a high current density. ..... Equivalent electrical circuit parameters for the corrosion process of S355 and ...

  9. Threshold Corrosion Fatigue of Welded Shipbuilding Steels.

    Science.gov (United States)

    1992-01-01

    8. J. C. Walter, E. Olbjorn, 0. Allstad and G. Elde, "Safety Against Corrosion Fatigue Offshore," Publication No. 94, Det Norske Ventas , Horik...Offshore. Publication No;. 94;, Det Norske Ventas , Horik, Norway, April 1976. 18. C. E. Jaske, D. Broek, J. E. Slater, W. E. Anderson. Corrosion Fatigue

  10. Electrochemical corrosion measurements on noble electrodeposits

    DEFF Research Database (Denmark)

    Christoffersen, Lasse; Maahn, Ernst Emanuel

    1998-01-01

    Novel electrodeposits are compared with hard chrome and electroless Ni-P with respect to production, corrosion resistance and hardness.......Novel electrodeposits are compared with hard chrome and electroless Ni-P with respect to production, corrosion resistance and hardness....

  11. Corrosion Behaviour of New Zr Alloys

    DEFF Research Database (Denmark)

    Tolksdorf, E.

    1974-01-01

    Corrosion studies have indicated that the most promising replacements for Zicaloy-2 are ZrCrFe, ZrVFe and probably ZrNbTa, provided they are in their optimized condition. These alloys are conventionally manufactured alloys. An internally oxidized ZrMgO alloy is even superior, from the corrosion...

  12. Corrosion of technical ceramics by molten aluminium

    NARCIS (Netherlands)

    Schwabe, U.; Wolff, L.R.; Loo, van F.J.J.; Ziegler, G.; With, de G.; Terpstra, R.A.; Metselaar, R.

    1989-01-01

    Corrosion investigations on various types of nonoxide technical ceramic materials, two types of silicon nitride (HIPRBSN and RBSN) and two types of silicon carbide (HIPSIC and SiSiC), were carried out in aluminum (Al99.99) melts. HIPRBSN showed nearly no corrosion attack under the most severe

  13. CORROSION RATE OF STEELS DX51D AND S220GD IN DIFFERENT CORROSION ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    Alina Crina CIUBOTARIU

    2016-06-01

    Full Text Available Corrosion in the marine environment is an important issue because the costs causes by marine corrosion increased year upon year. It is necessary a correctly approach to materials selection, protection and corrosion control to reduce this burden of wasted materials, wasted energy and wasted money. Many different types of corrosion attack can be observed to structures, ships and other equipment used in sea water service. Shipping containers are exposed to various corrosive mediums like as airborne salt, industrial pollutants, rain and saltwater. Transport damage during loading onto and unloading off trucks, train beds and ships breaches the paint coating which further contributes to corrosion. The result is shortened container life and high costs for container repair or replacement. The paper intends to evaluate, by gravimetric method, the corrosion rate and corrosion penetration rate of two types of carbon steel DX51D and S220GD. Carbon steel DX51D and hot-dip galvanized steel S220GD are used in marine and industrial applications for buildings cargo vessels, container ships and oil tankers. For testing it was used different corrosive environments: 5% NaOH solution; 5% HCL solution and 0.5M NaCl solution. The samples were immersed in 400mL of testing solution for exposure period of 28 days. Periodically at 3 days, 7 days, 14 days, 21 days and 28 days was measured de mass loss and evaluate the corrosion rate and corrosion stability coefficient. The steel DX51D was stable in 5% NaOH solution for 28 days, the values of corrosion stability coefficient was 7 after 3 days and 6 after 28 days of immersion in corrosive medium. In 5% HCL solution steels DX51D and S220GD was completely corroded in 21 days with a corrosion stability coefficient equal with 9 for 7 days and 8 for 21 days of immersion in corrosive solution. It was observed a good resistance for 3 days in 0.5M NaCl solution with a corrosion stability coefficient equal with 5, but after that

  14. Corrosion of high-density sintered tungsten alloys

    International Nuclear Information System (INIS)

    Batten, J.J.; Moore, B.T.

    1989-01-01

    In comparative corrosion tests, the corrosion resistance of an Australian tungsten alloy (95% W, 3.5% Ni, 1.5% Fe) was found to be superior to three other tungsten alloys and, under certain conditions, even more corrosion-resistant than pure tungsten. Corrosion resistance was evaluated after immersion in both distilled water and 5% sodium chloride solutions, and in cyclic humidity and salt mist environments. For all but the Australian alloy, the rate of corrosion in sodium chloride solution was markedly less than that in distilated water. In all cases, alloys containing copper had the greatest corrosion rates. Corrosion mechanisms were investigated using a scanning electron microscope, analysis of corrosion products and galvanic corrosion studies. For the alloys, corrosion was attributed primarily to a galvanic reaction. Whether the tungsten or binder phase of the alloy became anodic, and thus was attacked preferentially, depended upon alloy composition and corrosion environment. 16 refs., 4 tabs., 4 figs

  15. Aspects of high temperature corrosion of boiler tubes

    Energy Technology Data Exchange (ETDEWEB)

    Spiegel, M.; Bendick, W. [Salzgitter-Mannesmann-Forschung GmbH, Duisburg (Germany)

    2008-07-01

    The development of new boiler steels for power generation has to consider significant creep strength as well as oxidation and corrosion resistance. High temperature corrosion of boiler materials concerns steam oxidation as well as fireside corrosion of parts, in contact with the flue gas. It will be shown that depending on the quality of the fuel, especially chlorine and sulphur are responsible for most of the fireside corrosion problems. Corrosion mechanisms will be presented for flue gas induced corrosion (HCl) and deposit induced corrosion (chlorides and sulfates). Especially for the 700 C technology, deposit induced corrosion issues have to be considered and the mechanisms of corrosion by molten sulfates 'Hot Corrosion' will be explained. Finally, an overview will be given on the selection of suitable materials in order to minimise corrosion relates failures. (orig.)

  16. Launch Pad Coatings for Smart Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Bucherl, Cori N.; Li, Wenyan; Buhrow, Jerry W.; Curran, Jerome P.; Whitten, Mary C.

    2010-01-01

    Corrosion is the degradation of a material as a result of its interaction with the environment. The environment at the KSC launch pads has been documented by ASM International (formerly American Society for Metals) as the most corrosive in the US. The 70 tons of highly corrosive hydrochloric acid that are generated by the solid rocket boosters during a launch exacerbate the corrosiveness of the environment at the pads. Numerous failures at the pads are caused by the pitting of stainless steels, rebar corrosion, and the degradation of concrete. Corrosion control of launch pad structures relies on the use of coatings selected from the qualified products list (QPL) of the NASA Standard 5008A for Protective Coating of Carbon Steel, Stainless Steel, and Aluminum on Launch Structures, Facilities, and Ground Support Equipment. This standard was developed to establish uniform engineering practices and methods and to ensure the inclusion of essential criteria in the coating of ground support equipment (GSE) and facilities used by or for NASA. This standard is applicable to GSE and facilities that support space vehicle or payload programs or projects and to critical facilities at all NASA locations worldwide. Environmental regulation changes have dramatically reduced the production, handling, use, and availability of conventional protective coatings for application to KSC launch structures and ground support equipment. Current attrition rate of qualified KSC coatings will drastically limit the number of commercial off the shelf (COTS) products available for the Constellation Program (CxP) ground operations (GO). CxP GO identified corrosion detection and control technologies as a critical, initial capability technology need for ground processing of Ares I and Ares V to meet Constellation Architecture Requirements Document (CARD) CxP 70000 operability requirements for reduced ground processing complexity, streamlined integrated testing, and operations phase affordability

  17. Steam generator corrosion 2007; Dampferzeugerkorrosion 2007

    Energy Technology Data Exchange (ETDEWEB)

    Born, M. (ed.)

    2007-07-01

    Between 8th and 9th November, 2007, SAXONIA Standortentwicklungs- und -verwertungsgesellschaft GmbH (Freiberg, Federal Republic of Germany) performed the 3rd Freiberger discussion conference ''Fireside boiler corrosion''. The topics of the lectures are: (a) Steam generator corrosion - an infinite history (Franz W. Alvert); (b) CFD computations for thermal waste treatment plants - a contribution for the damage recognition and remedy (Klaus Goerner, Thomas Klasen); (c) Experiences with the use of corrosion probes (Siegfried R. Horn, Ferdinand Haider, Barbara Waldmann, Ragnar Warnecke); (d) Use of additives for the limitation of the high temperature chlorine corrosion as an option apart from other measures to the corrosion protection (Wolfgang Spiegel); (e) Current research results and aims of research with respect to chlorine corrosion (Ragnar Warnecke); (f) Systematics of the corrosion phenomena - notes for the enterprise and corrosion protection (Thomas Herzog, Wolfgang Spiegel, Werner Schmidl); (g) Corrosion protection by cladding in steam generators of waste incinerators (Joerg Metschke); (h) Corrosion protection and wear protection by means of thermal spraying in steam generators (Dietmar Bendix); (i) Review of thick film nickelized components as an effective protection against high-temperature corrosion (Johann-Wilhelm Ansey); (j) Fireproof materials for waste incinerators - characteristics and profile of requirement (Johannes Imle); (k) Service life-relevant aspects of fireproof linings in the thermal recycling of waste (Till Osthoevener and Wolfgang Kollenberg); (l) Alternatives to the fireproof material in the heating space (Heino Sinn); (m) Cladding: Inconal 625 contra 686 - Fundamentals / applications in boiler construction and plant construction (Wolfgang Hoffmeister); (n) Thin films as efficient corrosion barriers - thermal spray coating in waste incinerators and biomass firing (Ruediger W. Schuelein, Steffen Hoehne, Friedrich

  18. Brigitte SIMONOT et Gabriel GALLEZOT (2009) (dir.), L’entonnoir : Google sous la loupe des sciences de l’information et de la communication

    OpenAIRE

    Bonaccorsi, Julia

    2013-01-01

    Ce titre annonce d’emblée une posture critique et, plus largement, une promesse de dévoilement. L’approche communicationnelle, affirmée dès le sous-titre, saisit Google comme un objet de recherche à construire à distance des discours promotionnels ou pamphlétaires. La recherche collective prend appui sur une perspective sociotechnique, mais également sociopolitique du moteur de recherche et de ses usages, pour interroger la production de valeurs par la société Google. Le moteur est scruté au ...

  19. Corrosion study in molten fluoride salt

    International Nuclear Information System (INIS)

    Keny, S.J.; Kumbhar, A.G.; Rangarajan, S.; Gupta, V.K.; Maheshwari, N.K.; Vijayan, P.K.

    2013-01-01

    Corrosion behaviors of two alloys viz. Inconel 625 and Inconel 617 were tested in molten fluoride salts of lithium, sodium and potassium (FLiNaK) in the temperature range of 550-750 ℃ in a nickel lined Inconel vessel. Electrochemical polarization (Tafel plot) technique was used for this purpose. For both alloys, the corrosion rate was found to increase sharply beyond 650 ℃ . At 600 ℃ , Inconel 625 showed a decreasing trend in the corrosion rate over a period of 24 hours, probably due to changes in the surface conditions. After fifteen days, re-testing of Inconel 625 in the same melt showed an increase in the corrosion rate. Inconel 625 was found to be more corrosion resistant than Inconel 617. (author)

  20. Fuel corrosion processes under waste disposal conditions

    International Nuclear Information System (INIS)

    Shoesmith, D.W.

    1999-09-01

    Under the oxidizing conditions likely to be encountered in the Yucca Mountain Repository, fuel dissolution is a corrosion process involving the coupling of the anodic dissolution of the fuel with the cathodic reduction of oxidants available within the repository. The oxidants potentially available to drive fuel corrosion are environmental oxygen, supplied by the transport through the permeable rock of the mountain and molecular and radical species produced by the radiolysis of available aerated water. The mechanism of these coupled anodic and cathodic reactions is reviewed in detail. While gaps in understanding remain, many kinetic features of these reactions have been studied in considerable detail, and a reasonably justified mechanism for fuel corrosion is available. The corrosion rate is determined primarily by environmental factors rather than the properties of the fuel. Thus, with the exception of increase in rate due to an increase in surface area, pre-oxidation of the fuel has little effect on the corrosion rate

  1. Microencapsulation Technologies for Corrosion Protective Coating Applications

    Science.gov (United States)

    Li, Wenyan; Buhrow, Jerry; Jolley, Scott; Calle, Luz; Pearman, Benjamin; Zhang, Xuejun

    2015-01-01

    Microencapsulation technologies for functional smart Coatings for autonomous corrosion control have been a research area of strong emphasis during the last decade. This work concerns the development of pH sensitive micro-containers (microparticles and microcapsules) for autonomous corrosion control. This paper presents an overview of the state-of-the-art in the field of microencapsulation for corrosion control applications, as well as the technical details of the pH sensitive microcontainer approach, such as selection criteria for corrosion indicators and corrosion inhibitors; the development and optimization of encapsulation methods; function evaluation before and after incorporation of the microcontainers into coatings; and further optimization to improve coating compatibility and performance.

  2. Passive Corrosion Behavior of Alloy 22

    International Nuclear Information System (INIS)

    R.B. Rebak; J.H. Payer

    2006-01-01

    Alloy 22 (NO6022) was designed to stand the most aggressive industrial applications, including both reducing and oxidizing acids. Even in the most aggressive environments, if the temperature is lower than 150 F (66 C) Alloy 22 would remain in the passive state having particularly low corrosion rates. In multi-ionic solutions that may simulate the behavior of concentrated ground water, even at near boiling temperatures, the corrosion rate of Alloy 22 is only a few nano-meters per year because the alloy is in the complete passive state. The corrosion rate of passive Alloy 22 decreases as the time increases. Immersion corrosion testing also show that the newer generation of Ni-Cr-Mo alloys may offer a better corrosion resistance than Alloy 22 only in some highly aggressive conditions such as in hot acids

  3. Corrosion and Environmental Degradation, 2 Volume Set

    Science.gov (United States)

    Schütze, Michael; Cahn, Robert W.; Haasen, Peter; Kramer, E. J.

    2001-06-01

    Corrosion and corrosion protection is one of most important topics in applied materials science. Corrosion science is not only important from an economic point of view, but, due to its interdisciplinary nature combining metallurgy, materials physics and electrochemistry, it is also of high scientific interest. Nowadays corrosion science even gets new impetus from surface science and polymer chemistry. This two-volume reference work belonging to the well renown series Materials Science and Tehcnology provides the reader with a sound and broad survey on the whole subject - from the fundamentals to the latest research results. Written by a team of international top-experts it will become an indispensable reference for any materials scientist, physicist or chemist involved in corrosion science.

  4. Fuel corrosion processes under waste disposal conditions

    International Nuclear Information System (INIS)

    Shoesmith, D.W.

    2000-01-01

    The release of the majority of radionuclides from spent nuclear fuel under permanent disposal conditions will be controlled by the rate of dissolution of the UO 2 fuel matrix. In this manuscript the mechanism of the coupled anodic (fuel dissolution) and cathodic (oxidant reduction) reactions which constitute the overall fuel corrosion process is reviewed, and the many published observations on fuel corrosion under disposal conditions discussed. The primary emphasis is on summarizing the overall mechanistic behaviour and establishing the primary factors likely to control fuel corrosion. Included are discussions on the influence of various oxidants including radiolytic ones, pH, temperature, groundwater composition, and the formation of corrosion product deposits. The relevance of the data recorded on unirradiated UO 2 to the interpretation of spent fuel behaviour is included. Based on the review, the data used to develop fuel corrosion models under the conditions anticipated in Yucca Mountain (NV, USA) are evaluated

  5. Corrosion behaviour of cladded nickel base alloys

    International Nuclear Information System (INIS)

    Brandl, W.; Ruczinski, D.; Nolde, M.; Blum, J.

    1995-01-01

    As a consequence of the high cost of nickel base alloys their use as surface layers is convenient. In this paper the properties of SA-as well as RES-cladded NiMo 16Cr16Ti and NiCr21Mo14W being produced in single and multi-layer technique are compared and discussed with respect to their corrosion behaviour. Decisive criteria describing the qualities of the claddings are the mass loss, the susceptibility against intergranular corrosion and the pitting corrosion resistance. The results prove that RES cladding is the most suitable technique to produce corrosion resistant nickel base coatings. The corrosion behaviour of a two-layer RES deposition shows a better resistance against pitting than a three layer SAW cladding. 7 refs

  6. Numerical Study of Corrosion Crack Opening

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Frandsen, Henrik Lund; Svensson, Staffan

    2008-01-01

    is proportional. More recently, the constant of proportionality, the so-called crack-corrosion index, has been studied further with respect to its dependence on the diameter of the reinforcement and the concrete cover. In the present paper the above-mentioned work is presented and extended with more realistic 3D......-models of the cracked concrete beam. The crack-corrosion index is evaluated for a variation of different parameters, i.e. bar diameter, concrete cover, crack length and type of corrosion product. This paper is an extended version of a paper by Thoft-Christensen et al. (2005) presented at the IFIP WG 7.5 Conference...... for the corrosion crack opening. Experiments and theoretical analysis by a numerical method, FEM, support that the relation between the reduction of the reinforcement bar diameter due to corrosion and the corresponding increase in crack width for a given time interval, measured on the surface of a concrete specimen...

  7. High Temperature Corrosion on Biodust Firing

    DEFF Research Database (Denmark)

    Okoro, Sunday Chukwudi

    The high content of alkali metals and chlorine in biomass gives rise to fouling/slagging and corrosion of heat exchange components, such as superheaters, in biomass fired power plants. Increasing the lifetime of these components, and in addition, preventing unwarranted plant shutdowns due...... to their failure, requires understanding of the complex corrosion mechanisms, as well as development of materials that are resistant to corrosion under biomass firing conditions, thereby motivating the current work. To understand the mechanisms of corrosion attack, comprehensive analysis of corrosion products...... by the combined use of complementary information from microscopy, energy dispersive X-ray spectroscopy and various X-ray diffraction characterization techniques. In light of the wide variation in operating conditions in biomass fired power plants, systematic and well-controlled, but realistic laboratory scale...

  8. Some proposed mechanisms for internal cladding corrosion

    International Nuclear Information System (INIS)

    Bradbury, M.H.; Pickering, S.; Whitlow, W.H.

    1977-01-01

    In spite of extensive research during recent years, a comprehensive model for internal cladding corrosion in fast reactor oxide fuel pins has not yet been established. In this paper, a model is proposed which accounts for many of the features normally associated with this type of corrosion. The model is composed of a number of parts which describe the chronological sequence of events at the fuel/cladding interface. The corrosion reaction is visualised as being primarily chemical in character, involving the cladding steel, the fuel and the more aggressive fission products, notably caesium in the presence of oxygen. The model attempts to explain how corrosion starts, how it depends on the oxygen potential, why it occurs non-uniformly; also covered are phase changes within the cladding steel and morphological features such as the intergranular form of attack and the distribution of corrosion products in the fuel/cladding gap. (author)

  9. Stress corrosion of low alloy steel forgings

    International Nuclear Information System (INIS)

    Thornton, D.V.; Mould, P.B.; Patrick, E.C.

    1976-01-01

    The catastrophic failure of a steam turbine rotor disc at Hinkley Point 'A' Power station was shown to have been caused by the growth of a stress corrosion crack to critical dimensions. This failure has promoted great interest in the stress corrosion susceptibility of medium strength low alloy steel forgings in steam environments. Consequently, initiation and growth of stress corrosion cracks of typical disc steels have been investigated in steam and also in water at 95 0 C. Cracking has been shown to occur, predominantly in an intergranular manner, with growth rates of between 10 -9 and 10 -7 mm sec. -1 . It is observed that corrosion pitting and oxide penetration prior to the establishment of a stress corrosion crack in the plain samples. (author)

  10. Water side corrosion prevention in boilers

    International Nuclear Information System (INIS)

    Zeid, A.

    1993-01-01

    Corrosion may be defined as a naturally occurring physical and chemical deterioration of a material due to reaction with the environment or surrounding atmosphere. In boilers the material is subjected on both sides to two different media which may cause severe corrosion. At the water side the content of O 2 considered one of the principal factors which determine the extent of corrosion in the boiler tubes. This paper deals with certain conditions that result in the increase of O 2 in the boiler water and hence increase the corrosion rate, to minimize the effect of these conditions a chemical treatment was carried out the results obtained indicated the success of the treatment procedure in corrosion prevention and boiler material protection. The treatment is traditional. But the study indicates how a simple mean could be applied to solve a serious problem. 4 tab

  11. Some proposed mechanisms for internal cladding corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, M H; Pickering, S; Whitlow, W H [EURATOM (United Kingdom)

    1977-04-01

    In spite of extensive research during recent years, a comprehensive model for internal cladding corrosion in fast reactor oxide fuel pins has not yet been established. In this paper, a model is proposed which accounts for many of the features normally associated with this type of corrosion. The model is composed of a number of parts which describe the chronological sequence of events at the fuel/cladding interface. The corrosion reaction is visualised as being primarily chemical in character, involving the cladding steel, the fuel and the more aggressive fission products, notably caesium in the presence of oxygen. The model attempts to explain how corrosion starts, how it depends on the oxygen potential, why it occurs non-uniformly; also covered are phase changes within the cladding steel and morphological features such as the intergranular form of attack and the distribution of corrosion products in the fuel/cladding gap. (author)

  12. Inhibition of aluminum corrosion using Opuntia extract

    International Nuclear Information System (INIS)

    El-Etre, A.Y.

    2003-01-01

    The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions

  13. Corrosion surveillance in spent fuel storage pools

    International Nuclear Information System (INIS)

    Howell, J.P.

    1996-01-01

    In mid-1991, corrosion of aluminum-clad spent nuclear fuel was observed in the light-water filled basins at the Savannah River site. A corrosion surveillance program was initiated in the P, K, L-Reactor basins and in the Receiving Basin for Offsite Fuels (RBOF). This program verified the aggressive nature of the pitting corrosion and provided recommendations for changes in basin operations to permit extended longer term interim storage. The changes were implemented during 1994--1996 and have resulted in significantly improved basin water quality with conductivity in the 1--3 microS/cm range. Under these improved conditions, no new pitting has been observed over the last three years. This paper describes the corrosion surveillance program at SRS and what has been learned about the corrosion of aluminum-clad in spent fuel storage pools

  14. Fuel corrosion processes under waste disposal conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D.W. [Univ. of Western Ontario, Dept. of Chemistry, London, Ontario (Canada)

    1999-09-01

    Under the oxidizing conditions likely to be encountered in the Yucca Mountain Repository, fuel dissolution is a corrosion process involving the coupling of the anodic dissolution of the fuel with the cathodic reduction of oxidants available within the repository. The oxidants potentially available to drive fuel corrosion are environmental oxygen, supplied by the transport through the permeable rock of the mountain and molecular and radical species produced by the radiolysis of available aerated water. The mechanism of these coupled anodic and cathodic reactions is reviewed in detail. While gaps in understanding remain, many kinetic features of these reactions have been studied in considerable detail, and a reasonably justified mechanism for fuel corrosion is available. The corrosion rate is determined primarily by environmental factors rather than the properties of the fuel. Thus, with the exception of increase in rate due to an increase in surface area, pre-oxidation of the fuel has little effect on the corrosion rate.

  15. Corrosion protection with eco-friendly inhibitors

    Science.gov (United States)

    Shahid, Muhammad

    2011-12-01

    Corrosion occurs as a result of the interaction of a metal with its environment. The extent of corrosion depends on the type of metal, the existing conditions in the environment and the type of aggressive ions present in the medium. For example, CO3-2 and NO-3 produce an insoluble deposit on the surface of iron, resulting in the isolation of metal and consequent decrease of corrosion. On the other hand, halide ions are adsorbed selectively on the metal surface and prevent formation of the oxide phase on the metal surface, resulting in continuous corrosion. Iron, aluminum and their alloys are widely used, both domestically and industrially. Linear alkylbenzene and linear alkylbenzene sulfonate are commonly used as detergents. They have also been found together in waste water. It is claimed that these chemicals act as inhibitors for stainless steel and aluminum. Release of toxic gases as a result of corrosion in pipelines may lead in certain cases to air pollution and possible health hazards. Therefore, there are two ways to look at the relationship between corrosion and pollution: (i) corrosion of metals and alloys due to environmental pollution and (ii) environmental pollution as a result of corrosion protection. This paper encompasses the two scenarios and possible remedies for various cases, using 'green' inhibitors obtained either from plant extracts or from pharmaceutical compounds. In the present study, the effect of piperacillin sodium as a corrosion inhibitor for mild steel was investigated using a weight-loss method as well as a three-electrode dc electrochemical technique. It was found that the corrosion rate decreased as the concentration of the inhibitor increased up to 9×10-4 M 93% efficiency was exhibited at this concentration.

  16. Improvements in zirconium alloy corrosion resistance

    International Nuclear Information System (INIS)

    Kilp, G.R.; Thornburg, D.R.; Comstock, R.J.

    1990-01-01

    The corrosion rates of a series of Zircaloy 4 and Zr-Nb alloys were evaluated in long-term (exceeding 500 days in some cases) autoclave tests. The testing was done at various conditions including 633 K (680 F) water, 633 K (650 F) water, 633 k (680 F) lithiated water (70 PPM/0.01 molal lithium), and 673 K (750 F) steam. Materials evaluated are from the following three groups: (1) standard Zircaloy 4; (2) Zircaloy 4 with tightened controls on chemistry limits and heat-treatment history; and (3) Zr-Nb alloys. To optimize the corrosion resistance of the Zircaloy 4 material, the effects of specific chemistry controls (tighter limits on nitrogen, oxygen, silicon, carbon and tin) were evaluated. Also the effects of the thermal history, as measured by integrated annealing of ''A'' time were determined. The ''A'' times ranged from 0.1x10 -18 (h) to 46x10 -18 (h). A material referred to as ''Improved Zircaloy 4'', having optimized chemistry and ''A'' time levels for reduced corrosion, has been developed and tested. This material has a reduced and more uniform corrosion rate compared to the prior Zircaloy 4 material. Alternative alloys were also evaluated for potential improvement in cladding corrosion resistance. ZIRLO TM material was chosen for development and has been included in the long-term corrosion testing. Demonstration fuel assemblies using ZIRLO cladding are now operating in a commercial reactor. The results for the various test conditions and compositions are reported and the relative corrosion characteristics summarized. Based on the BR-3 data, there is a ranking correspondence between in-reactor corrosion and autoclave testing in lithiated water. In particular, the ZIRLO material has significantly improved relative corrosion resistance in the lithiated water tests. Reduced Zircaloy-4 corrosion rates are also obtained from the tighter controls on the chemistry (specifically lower tin, nitrogen, and carbon; higher silicon; and reduced oxygen variability) and ''A

  17. Ultrasonic monitoring of pitting corrosion

    Science.gov (United States)

    Jarvis, A. J. C.; Cegla, F. B.; Bazaz, H.; Lozev, M.

    2013-01-01

    Exposure to corrosive substances in high temperature environments can cause damage accumulation in structural steels, particularly in the chemical and petrochemical industries. The interaction mechanisms are complex and varied; however initial damage propagation often manifests itself in the form of localized areas of increased material loss. Recent development of an ultrasonic wall thickness monitoring sensor capable of withstanding temperatures in excess of 500°C has allowed permanent monitoring within such hostile environments, providing information on how the shape of a pulse which has reflected from a corroding surface can change over time. Reconstructing localized corrosion depth and position may be possible by tracking such changes in reflected pulse shape, providing extra information on the state of the backwall and whether process conditions should be altered to increase plant life. This paper aims to experimentally investigate the effect certain localized features have on reflected pulse shape by `growing' artificial defects into the backwall while wall thickness is monitored using the sensor. The size and complexity of the three dimensional scattering problem lead to the development of a semi-analytical simulation based on the distributed point source method (DPSM) which is capable of simulating pulse reflection from complex surfaces measuring approximately 17×10λ Comparison to experimental results show that amplitude changes are predicted to within approximately 1dB and that pulse shape changes are accurately modelled. All experiments were carried out at room temperature, measurements at high temperature will be studied in the future.

  18. Corrosion inhibitors 26. Pt. 1

    International Nuclear Information System (INIS)

    Horner, L.; Pliefke, E.

    1981-01-01

    The analysis of the protective coating produced during the corrosion of copper in the presence of 2-aminopyrimidine (2-AP) is consistent with the composition [Cu 1 + -2-AP-Cl]sub(n). The individual units form a three-dimensional macro-structure via chloride bridging and hydrogen bonding. The assignment of the structure was supported by NMR, IR, UV and magnetic susceptibility measurements and an X-ray investigation using the Debye-Scherrer powder method. The thermal behaviour of the coating was studied by mass-spectral and DTA (differential thermal analysis) methods. Radiochemical experiments were carried out using active copper samples (i.e. containing 64 Cu), or using added 64 CuCl and 64 CuCl 2 in the corrosion of non-active copper both in the presence and absence of added 2-AP. The results elucidate the exchange reactions at the copper surface between dissolved and metallic components. The equilibrium between Cu 2 + and metallic copper on the one hand and 2 Cu 1 + ions on the other is central to the problem, as is also the dissociation of the [Cu 1 + -2-AP-Cl]sub(n) complex. The concepts here developed were confirmed by studies of the autoxidation of CuCl and CuO in the presence and absence of 2-AP. (orig.)

  19. East Carnduff Unit: corrosion problems

    Energy Technology Data Exchange (ETDEWEB)

    Banks, C D

    1966-07-01

    Waterflooding of the East Carnduff Unit began in late 1962. The first injection line leak was discovered April 29, 1965. The first 6 leaks in the East Carnduff Unit occurred within a period of less than one month--a very startling and serious warning of pending problems. Analysis of the pipe removed showed a deep pit covered by a severe scale in the piping fitting. Several remedial actions were tried in order to develop the present inhibition program. First, the lines were cleaned as well as possible utilizing rubber pig spheres with normal injection pressure. This proved very effective and 2 passes wiped out most of the scale in the lines. Only one line required acid. After the lines had been cleaned, a water treating rate of an organic amine corrosion inhibitor, 10 ppm of the scale inhibitor, and bactericide at the rate of 40 ppm slugs 2 days per month was initiated. The above treating program is in use at the present time and is maintaining a very low leak frequency. This experience has demonstrated 2 important points in waterflood operations: (1) a bare piping system in warm brine service requires constant attention to insure that it is being kept clean; and (2) reliance cannot be placed on any one method of checking corrosion rates.

  20. Effect of the cooking method (grilling, roasting, frying and sous-vide) on the oxidation of thiols, tryptophan, alkaline amino acids and protein cross-linking in jerky chicken.

    Science.gov (United States)

    Silva, Fábio A P; Ferreira, Valquíria C S; Madruga, Marta S; Estévez, Mario

    2016-08-01

    Broiler breast ( pectoralis major ) meat was submitted to salting with NaCl + NaNO 3 followed by a drying process to produce jerky-type chicken. The final product (raw broiler charqui) was desalted and then cooked using grilled, roasted, fried and sous-vide techniques. Sous-vide cooked samples showed lowest results of moisture loss compared to roasted and fried ones. Fatty acid profile suffered minor changes after cooking of broiler charqui. Regarding to protein oxidation, tryptophan fluorescence, protein carbonylation and disulphide bonds formation of chicken charqui were affected by cooking temperature while free thiol groups, Schiff base formation and hardness were mostly impacted by the length of cooking. Instrumental color of broiler charqui was affected by the type of cooking, being closely related with Maillard products formation. In conclusion, sous-vide technique seems to be the most advantageous cooking method to obtain high-quality ready-to-eat chicken charqui.

  1. Pipeline corrosion prevention by pH stabilization or corrosion inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Nyborg, Rolf [Institute for Energy Technology, Oslo (Norway)

    2009-07-01

    In many offshore oil and gas projects the pipeline costs are a considerable part of the investment and can become prohibitively high if the corrosivity of the fluid necessitates the use of corrosion resistant alloys instead of carbon steel. Development of more robust and reliable methods for internal corrosion control can increase the application range of carbon steel and therefore have a large economic impact. Corrosion control of carbon steel pipelines has traditionally often been managed by the use of corrosion inhibitors. The pH stabilization technique has been successfully used for corrosion control of several large wet gas pipelines in the last years. This method has advantages over film forming corrosion inhibitors when no or little formation water is produced. The use of corrosion inhibitors in multiphase pipelines implies several challenges which are not fully accounted for in traditional corrosion inhibitor testing procedures. Specialized test procedures have been developed to take account for the presence of emulsions dispersions and sand and clay particles in corrosion inhibitor testing. (author)

  2. Corrosion of circulating water pipings in thermal and nuclear power stations and corrosion prevention measures

    International Nuclear Information System (INIS)

    Hachiya, Minoru

    1982-01-01

    In the age of energy conservation at present, the power generation facilities have been examined from the viewpoint of performance, endurance and economy, and in particular, the prevention of the loss due to the corrosion of various facilities is one of most important problems. Since circulating water pipings are in contact with sea water and soil, the peculiar corrosion phenomena are brought about on their external and internal surfaces. Namely, the pitting corrosion due to the environment of soil quality difference, the defects of coating and the contact with reinforcing bars in concrete occurs on the external surface, and the overall corrosion due to the increase of flow velocity and the pitting corrosion due to the defects of coating, the contact with different kinds of metals and the gap in corrosion-resistant steel occur on the internal surface. As the measures for corrosion prevention, corrosion-preventive coating and electric corrosion prevention are applied. The principle, the potential and current density, the system, the design procedure and the examples of application of electric corrosion prevention are described. (Kako, I.)

  3. Exposure testing of fasteners in preservative treated wood: Gravimetric corrosion rates and corrosion product analyses

    Energy Technology Data Exchange (ETDEWEB)

    Zelinka, Samuel L., E-mail: szelinka@fs.fed.u [USDA Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726 (United States); Sichel, Rebecca J. [College of Engineering, University of Wisconsin, Madison, WI 53706 (United States); Stone, Donald S. [Department of Materials Science and Engineering, College of Engineering, University of Wisconsin, Madison, WI 53706 (United States)

    2010-12-15

    Research highlights: {yields} The composition of the corrosion products was similar for the nail head and shank. {yields} Reduced copper was not detected on any of the fasteners. {yields} Measured corrosion rates were between 1 and 35 {mu}m year{sup -1}. - Abstract: Research was conducted to determine the corrosion rates of metals in preservative treated wood and also understand the mechanism of metal corrosion in treated wood. Steel and hot-dip galvanized steel fasteners were embedded in wood treated with one of six preservative treatments and exposed to 27 {sup o}C at 100% relative humidity for 1 year. The corrosion rate was determined gravimetrically and the corrosion products were analyzed with scanning electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. Although the accepted mechanism of corrosion in treated wood involves the reduction of cupric ions from the wood preservative, no reduced copper was found on the corrosion surfaces. The galvanized corrosion products contained sulfates, whereas the steel corrosion products consisted of iron oxides and hydroxides. The possible implications and limitations of this research on fasteners used in building applications are discussed.

  4. Prévision de l'épaisseur du film passif d'un acier inoxydable 316L soumis au fretting corrosion grâce au Point Defect Model, PDM Predicting the steady state thickness of passive films with the Point Defect Model in fretting corrosion experiments

    Directory of Open Access Journals (Sweden)

    Geringer Jean

    2013-11-01

    Full Text Available Les implants orthopédiques de hanche ont une durée de vie d'environ 15 ans. Par exemple, la tige fémorale d'un tel implant peut être réalisée en acier inoxydable 316L ou 316LN. Le fretting corrosion, frottement sous petits déplacements, peut se produire pendant la marche humaine en raison des chargements répétés entre le métal de la prothèse et l'os. Plusieurs investigations expérimentales du fretting corrosion ont été entreprises. Cette couche passive de quelques nanomètres, à température ambiante, est le point clef sur lequel repose le développement de notre civilisation, selon certains auteurs. Ce travail vise à prédire les épaisseurs de cette couche passive de l'acier inoxydable soumis au fretting corrosion, avec une attention spécifique sur le rôle des protéines. Le modèle utilisé est basé sur le Point Defect Model, PDM (à une échelle microscopique et une amélioration de ce modèle en prenant en compte le processus de frottement sous petits débattements. L'algorithme génétique a été utilisé pour optimiser la convergence du problème. Les résultats les plus importants sont, comme démontré avec les essais expérimentaux, que l'albumine, la protéine étudiée, empêche les dégradations de l'acier inoxydable aux plus faibles concentrations d'ions chlorure ; ensuite, aux plus fortes concentrations de chlorures, un temps d'incubation est nécessaire pour détruire le film passif. Some implants have approximately a lifetime of 15 years. The femoral stem, for example, should be made of 316L/316LN stainless steel. Fretting corrosion, friction under small displacements, should occur during human gait, due to repeated loadings and un-loadings, between stainless steel and bone for instance. Some experimental investigations of fretting corrosion have been practiced. As well known, metallic alloys and especially stainless steels are covered with a passive film that prevents from the corrosion and degradation

  5. 49 CFR 192.461 - External corrosion control: Protective coating.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false External corrosion control: Protective coating... for Corrosion Control § 192.461 External corrosion control: Protective coating. (a) Each external protective coating, whether conductive or insulating, applied for the purpose of external corrosion control...

  6. System for corrosion monitoring in pipeline applying fuzzy logic mathematics

    Science.gov (United States)

    Kuzyakov, O. N.; Kolosova, A. L.; Andreeva, M. A.

    2018-05-01

    A list of factors influencing corrosion rate on the external side of underground pipeline is determined. Principles of constructing a corrosion monitoring system are described; the system performance algorithm and program are elaborated. A comparative analysis of methods for calculating corrosion rate is undertaken. Fuzzy logic mathematics is applied to reduce calculations while considering a wider range of corrosion factors.

  7. To the corrosion of austenitic steels in sodium loops

    International Nuclear Information System (INIS)

    Schad, M.

    1978-03-01

    This report describes the comparison between experimental corrosion and calculated corrosion effects on austenitic steels exposed to liquid sodium. As basis for the calculations served a diffusion model. The comparison showed that the model is able to predict the corrosion effects. In addition the model was used to calculate the corrosion effect along an actual fuel rod. (orig.) [de

  8. 49 CFR 193.2631 - Internal corrosion control.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control. 193.2631 Section 193... GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2631 Internal corrosion control. Each component that is subject to internal corrosive attack must be protected from internal corrosion by— (a...

  9. 49 CFR 192.475 - Internal corrosion control: General.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Internal corrosion control: General. 192.475... Control § 192.475 Internal corrosion control: General. (a) Corrosive gas may not be transported by... taken to minimize internal corrosion. (b) Whenever any pipe is removed from a pipeline for any reason...

  10. Corrosion of aluminium in soft drinks.

    Science.gov (United States)

    Seruga, M; Hasenay, D

    1996-04-01

    The corrosion of aluminium (Al) in several brands of soft drinks (cola- and citrate-based drinks) has been studied, using an electrochemical method, namely potentiodynamic polarization. The results show that the corrosion of Al in soft drinks is a very slow, time-dependent and complex process, strongly influenced by the passivation, complexation and adsorption processes. The corrosion of Al in these drinks occurs principally due to the presence of acids: citric acid in citrate-based drinks and orthophosphoric acid in cola-based drinks. The corrosion rate of Al rose with an increase in the acidity of soft drinks, i.e. with increase of the content of total acids. The corrosion rates are much higher in the cola-based drinks than those in citrate-based drinks, due to the facts that: (1) orthophosphoric acid is more corrosive to Al than is citric acid, (2) a quite different passive oxide layer (with different properties) is formed on Al, depending on whether the drink is cola or citrate based. The method of potentiodynamic polarization was shown as being very suitable for the study of corrosion of Al in soft drinks, especially if it is combined with some non-electrochemical method, e.g. graphite furnace atomic absorption spectrometry (GFAAS).

  11. Corrosion in the nuclear power industry

    International Nuclear Information System (INIS)

    Danko, J.C.

    1987-01-01

    This article reviews the major corrosion problems in light water reactors, the research on the corrosion mechanism(s), and the development of engineering solutions and their implementation. To understand the occurrence of corrosion problems, a brief historical perspective of the corrosion design basis of commercial light water reactors, boiling water, and pressurized water reactors is necessary. Although corrosion was considered in the plant designs, it was not viewed as a serious problem. This was based on the results of laboratory experiments and in-reactor tests that did not indicate any major corrosion problems with the materials selected for the plant construction. However, the laboratory tests did not necessarily reproduce the reactor operating conditions and the early in-reactor test did not fully represent the commercial reactor conditions in all cases, and, finally, the test times were indeed of short duration relative to the plant design lifetime of 40 years. Thus, the design basis for the materials selection was determined on the favorable but limited test data that were available, and corrosion limitations on component integrity were therefore not anticipated

  12. Corrosion protection of reusable surgical instruments.

    Science.gov (United States)

    Shah, Sadiq; Bernardo, Mildred

    2002-01-01

    To understand the corrosion properties of surgical scissors, 416 stainless steel disks and custom electrodes were used as simulated surfaces under various conditions. These simulated surfaces were exposed to tap water and 400-ppm synthetic hard water as Ca2CO3 under different conditions. The samples were evaluated by various techniques for corrosion potential and the impact of environmental conditions on the integrity of the passive film. The electrodes were used to monitor the corrosion behavior by potentiodynamic polarization technique in water both in the presence and absence of a cleaning product. The surface topography of the 416 stainless steel disks was characterized by visual observations and scanning electron microscopy (SEM), and the surface chemistry of the passive film on the surface of the scissors was characterized by x-ray photoelectron spectroscopy (XPS). The results suggest that surgical instruments made from 416 stainless steel are not susceptible to uniform corrosion; however, they do undergo localized corrosion. The use of suitable cleaning products can offer protection against localized corrosion during the cleaning step. More importantly, the use of potentiodynamic polarization techniques allowed for a quick and convenient approach to evaluate the corrosion properties of surgical instruments under a variety of simulated-use environmental conditions.

  13. Task E container corrosion studies: Annual report

    International Nuclear Information System (INIS)

    Bunnell, L.R.; Doremus, L.A.; Topping, J.B.; Duncan, D.R.

    1994-06-01

    The Pacific Northwest Laboratory is conducting the Solid Waste Technology Support Program (SWTSP) for Westinghouse Hanford Company (WHC). Task E is the Container Corrosion Study Portion of the SWTSP that will perform testing to provide defensible data on the corrosion of low-carbon steel, as used in drums to contain chemical and radioactive wastes at the Hanford Site. A second objective of Task E is to provide and test practical alternative materials that have higher corrosion resistance than low-carbon steel. The scope of work for fiscal year (FY) 1993 included initial testing of mild steel specimens buried in Hanford soils or exposed to atmospheric corrosion in metal storage sheds. During FY 1993, progress was made in three areas of Task E. First, exposure of test materials began at the Soil Corrosion Test Site where low-carbon steel specimens were placed in the soil in five test shafts at depths of 9 m (30 ft). Second, the corrosion measurement of low-carbon steel in the soil of two solid waste trenches continued. The total exposure time is ∼ 500 days. Third, an atmospheric corrosion test of low-carbon steel was put initiated in a metal shed (Building 2401-W) in the 200 West Area. This annual report describes the Task E efforts and provides a current status

  14. Corrosion induced failure analysis of subsea pipelines

    International Nuclear Information System (INIS)

    Yang, Yongsheng; Khan, Faisal; Thodi, Premkumar; Abbassi, Rouzbeh

    2017-01-01

    Pipeline corrosion is one of the main causes of subsea pipeline failure. It is necessary to monitor and analyze pipeline condition to effectively predict likely failure. This paper presents an approach to analyze the observed abnormal events to assess the condition of subsea pipelines. First, it focuses on establishing a systematic corrosion failure model by Bow-Tie (BT) analysis, and subsequently the BT model is mapped into a Bayesian Network (BN) model. The BN model facilitates the modelling of interdependency of identified corrosion causes, as well as the updating of failure probabilities depending on the arrival of new information. Furthermore, an Object-Oriented Bayesian Network (OOBN) has been developed to better structure the network and to provide an efficient updating algorithm. Based on this OOBN model, probability updating and probability adaptation are performed at regular intervals to estimate the failure probabilities due to corrosion and potential consequences. This results in an interval-based condition assessment of subsea pipeline subjected to corrosion. The estimated failure probabilities would help prioritize action to prevent and control failures. Practical application of the developed model is demonstrated using a case study. - Highlights: • A Bow-Tie (BT) based corrosion failure model linking causation with the potential losses. • A novel Object-Oriented Bayesian Network (OOBN) based corrosion failure risk model. • Probability of failure updating and adaptation with respect to time using OOBN model. • Application of the proposed model to develop and test strategies to minimize failure risk.

  15. Marine atmospheric corrosion of carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Morcillo, M.; Alcantara, J.; Diaz, I.; Chico, B.; Simancas, J.; Fuente, D. de la

    2015-07-01

    Basic research on marine atmospheric corrosion of carbon steels is a relatively young scientific field and there continue to be great gaps in this area of knowledge. The presence of akaganeite in the corrosion products that form on steel when it is exposed to marine atmospheres leads to a notable increase in the corrosion rate. This work addresses the following issues: (a) environmental conditions necessary for akaganeite formation; (b) characterisation of akaganeite in the corrosion products formed; (c) corrosion mechanisms of carbon steel in marine atmospheres; (d) exfoliation of rust layers formed in highly aggressive marine atmospheres; (e) long-term corrosion rate prediction; and (f) behaviour of weathering steels. Field research has been carried out at Cabo Vilano wind farm (Camarinas, Galicia) in a wide range of atmospheric salinities and laboratory work involving the use of conventional atmospheric corrosion techniques and near-surface and bulk sensitive analytical techniques: scanning electron microscopy (SEM)/energy dispersive spectrometry (EDS), X-ray diffraction (XRD), Mossbauer spectroscopy and SEM/μRaman spectroscopy. (Author)

  16. Steel corrosion in radioactive waste storage tanks

    International Nuclear Information System (INIS)

    Carranza, Ricardo M.; Giordano, Celia M.; Saenz, E.; Weier, Dennis R.

    2004-01-01

    A collaborative study is being conducted by CNEA and USDOE (Department of Energy of the United States of America) to investigate the effects of tank waste chemistry on radioactive waste storage tank corrosion. Radioactive waste is stored in underground storage tanks that contain a combination of salts, consisting primarily of sodium nitrate, sodium nitrite and sodium hydroxide. The USDOE, Office of River Protection at the Hanford Site, has identified a need to conduct a laboratory study to better understand the effects of radioactive waste chemistry on the corrosion of waste storage tanks at the Hanford Site. The USDOE science need (RL-WT079-S Double-Shell Tanks Corrosion Chemistry) called for a multi year effort to identify waste chemistries and temperatures within the double-shell tank (DST) operating limits for corrosion control and operating temperature range that may not provide the expected corrosion protection and to evaluate future operations for the conditions outside the existing corrosion database. Assessment of corrosion damage using simulated (non-radioactive) waste is being made of the double-shell tank wall carbon steel alloy. Evaluation of the influence of exposure time, and electrolyte composition and/or concentration is being also conducted. (author) [es

  17. Physicochemical and microbiological changes during the refrigerated storage of lamb loins sous-vide cooked at different combinations of time and temperature.

    Science.gov (United States)

    Roldán, Mar; Antequera, Teresa; Hernández, Alejandro; Ruiz, Jorge

    2015-10-01

    This study aimed to determine the influence of cooking temperature (either 60 ℃ or 80 ℃) and time (6 h or 24 h) on the physicochemical (weight loss, moisture content, instrumental color, instrumental texture, lipid and protein oxidation) and microbiological changes underwent by sous-vide cooked lamb loins during refrigerated storage for 30 days. There was a slight trend to decreasing weight losses in some of the cooking treatments, but only in samples cooked at 60 ℃ for 6 h it was paralleled with an increase in moisture content. The only noteworthy oxidative change was a marked decrease in conjugated dienes after two weeks of storage in samples cooked at 80 ℃ for 24 h. Neither instrumental texture nor color showed noticeable variations during the storage. Microbial population remained quite low during the whole refrigerated storage. Overall, most of the studied parameters showed only scarce changes throughout 30 days of refrigerated storage that most likely would not influence the quality of sous-vide cooked loin lambs. © The Author(s) 2014.

  18. Oxidation of ordinary steels or alloys heated in carbon dioxide under pressure; Oxydation d'aciers ordinaires ou allies chauffes dans le gaz carbonique sous pression

    Energy Technology Data Exchange (ETDEWEB)

    Leclercq, D; Chevilliard, C; Darras, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Selection tests were carried out on commercial steels from the viewpoint of their resistance to oxidation in carbon dioxide, under 25 atmospheres pressure, between 350 and 600 deg. C. Comparative curve of oxidation kinetics were obtained, from which the influence of various additive elements can be found; small amounts of aluminium particularly seem to be favourable in the case of only slightly alloyed steels. (author) [French] Des essais de selection d'aciers commerciaux ont ete effectues quant a leur resistance a l'oxydation dans le gaz carbonique, sous pression de 25 atmospheres, ente 350 et 600 deg. C. Des courbes comparatives de cinetique d'oxydation ont ete obtenues, ce qui permet de degager l'influence de divers elements d'addition; de faibles teneurs en aluminium apparaissent notamment favorables dans le cas des aciers peu allies. L'acier inoxydable 18-8 a egalement ete etudie, notamment sous forme de tubes minces. Son comportement est bon jusqu'au moins 600 deg. C dans ces conditions. (auteur)

  19. Effect of different temperature-time combinations on physicochemical, microbiological, textural and structural features of sous-vide cooked lamb loins.

    Science.gov (United States)

    Roldán, Mar; Antequera, Teresa; Martín, Alberto; Mayoral, Ana Isabel; Ruiz, Jorge

    2013-03-01

    Lamb loins were subjected to sous-vide cooking at different combinations of temperature (60, 70, and 80 °C) and time (6, 12, and 24 h). Different physicochemical, histological and structural parameters were studied. Increasing cooking temperatures led to higher weight losses and lower moisture contents, whereas the effect of cooking time on these variables was limited. Samples cooked at 60 °C showed the highest lightness and redness, while increasing cooking temperature and cooking time produced higher yellowness values. Most textural variables in a texture profile analysis showed a marked interaction between cooking temperature and time. Samples cooked for 24h showed significantly lower values for most of the studied textural parameters for all the temperatures considered. Connective tissue granulation at 60 °C and gelation at 70 °C were observed in the SEM micrographs. The sous-vide cooking of lamb loins dramatically reduced microbial population even with the less intense heat treatment studied (60 °C-6 h). Copyright © 2012 Elsevier Ltd. All rights reserved.

  20. Méthode d'estimation des tassements des sols fins sous les remblais d'infrastructures ferroviaires pour lignes à grande vitesse

    Science.gov (United States)

    Said Alami, Soukaina; Reiffsteck, Philippe; Cuira, Fahd

    2018-02-01

    Le besoin de maîtriser les déformations des sols sous les remblais destinés à recevoir les structures de lignes à grande vitesse, en fait un enjeu important pour ces projets. Toutefois, de nombreuses difficultés ont été soulevées liées principalement au grand nombre d'incertitudes qui entourent le phénomène. En effet, la caractérisation géologique et géotechnique dépend de sondages et d'essais où le risque de remaniement est important et dont l'interprétation est, souvent, délicate. Cet article présente une procédure de calcul qui permettrait en pratique d'évaluer le tassement sous remblai avec une bonne précision et qui a été validée sur un certain nombre d'ouvrages. Pour cela, des corrections sont introduites aux méthodes usuelles de calcul permettant d'approcher les valeurs mesurées sur chantier.

  1. Corrosion problems of materials for mechanical, power and chemical engineering

    International Nuclear Information System (INIS)

    Bouska, P.; Cihal, V.; Malik, K.; Vyklicky, M.; Stefec, R.

    1988-01-01

    The proceedings contain 47 contributions, out of which 8 have been inputted in INIS. These are concerned with various corrosion problems of WWER primary circuit components and their testing. The factors affecting the corrosion resistance are analyzed, the simultaneous corrosion action of decontamination of steels is assessed, and the corrosion cracking of special steels is dealt with. The effects of deformation on the corrosion characteristics are examined for steel to be used in fast reactors. The corrosion potentials were measured for various steels. A testing facility for corrosion-mechanical tests is briefly described. (M.D.). 5 figs., 5 tabs., 25 refs

  2. Atmospheric corrosion of metals in industrial city environment

    Directory of Open Access Journals (Sweden)

    Elzbieta Kusmierek

    2015-06-01

    Full Text Available Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust.

  3. Atmospheric corrosion of metals in industrial city environment.

    Science.gov (United States)

    Kusmierek, Elzbieta; Chrzescijanska, Ewa

    2015-06-01

    Atmospheric corrosion is a significant problem given destruction of various materials, especially metals. The corrosion investigation in the industrial city environment was carried out during one year exposure. Corrosion potential was determined using the potentiometric method. The highest effect of corrosion processes was observed during the winter season due to increased air pollution. Corrosion of samples pre-treated in tannic acid before the exposure was more difficult compared with the samples without pretreatment. The corrosion products determined with the SEM/EDS method prove that the most corrosive pollutants present in the industrial city air are SO2, CO2, chlorides and dust.

  4. Virtual Instrumentation Corrosion Controller for Natural Gas Pipelines

    Science.gov (United States)

    Gopalakrishnan, J.; Agnihotri, G.; Deshpande, D. M.

    2012-12-01

    Corrosion is an electrochemical process. Corrosion in natural gas (methane) pipelines leads to leakages. Corrosion occurs when anode and cathode are connected through electrolyte. Rate of corrosion in metallic pipeline can be controlled by impressing current to it and thereby making it to act as cathode of corrosion cell. Technologically advanced and energy efficient corrosion controller is required to protect natural gas pipelines. Proposed virtual instrumentation (VI) based corrosion controller precisely controls the external corrosion in underground metallic pipelines, enhances its life and ensures safety. Designing and development of proportional-integral-differential (PID) corrosion controller using VI (LabVIEW) is carried out. When the designed controller is deployed at field, it maintains the pipe to soil potential (PSP) within safe operating limit and not entering into over/under protection zone. Horizontal deployment of this technique can be done to protect all metallic structure, oil pipelines, which need corrosion protection.

  5. Corrosion and alteration of materials from the nuclear industry

    International Nuclear Information System (INIS)

    Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Feron, D.; Guerin, Y.; Latge, C.; Limoge, Y.; Madic, C.; Santarini, G.; Seiler, J.M.; Vernaz, E.; Richet, C.

    2010-01-01

    The control of the corrosion phenomenon is of prime importance for the nuclear industry. The efficiency and the safety of facilities can be affected by this phenomenon. The nuclear industry has to face corrosion for a large variety of materials submitted to various environments. Metallic corrosion operates in the hot and aqueous environment of water reactors which represent the most common reactor type in the world. Progresses made in the control of the corrosion of the different components of these reactors allow to improve their safety. Corrosion is present in the facilities of the back-end of the fuel cycle as well (corrosion in acid environment in fuel reprocessing plants, corrosion of waste containers in disposal and storage facilities, etc). The future nuclear systems will widen even more the range of materials to be studied and the situations in which they will be placed (corrosion by liquid metals or by helium impurities). Very often, corrosion looks like a patchwork of particular cases in its description. The encountered corrosion problems and their study are presented in this book according to chapters representing the main sectors of the nuclear industry and classified with respect to their phenomenology. This monograph illustrates the researches in progress and presents some results of particular importance obtained recently. Content: 1 - Introduction: context, stakes and goals; definition of corrosion; a complex science; corrosion in the nuclear industry; 2 - corrosion in water reactors - phenomenology, mechanisms, remedies: A - uniform corrosion: mechanisms, uniform corrosion of fuel cladding, in-situ measurement of generalized corrosion rate by electrochemical methods, uniform corrosion of nickel alloys, characterization of the passive layer and growth mechanisms, the PACTOLE code - an integrating tool, influence of water chemistry on corrosion and contamination, radiolysis impact on uniform corrosion; B - stress corrosion: stress corrosion cracking

  6. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  7. The resistance of titanium to pitting, microbially induced corrosion and corrosion in unsaturated conditions

    Energy Technology Data Exchange (ETDEWEB)

    Shoesmith, D W; Ikeda, B M

    1997-04-01

    Titanium and its alloys (Grades-2, -12, -16) are candidate materials for Canadian nuclear waste containers on the basis of their apparent immunity to many localized corrosion processes. This simplifies markedly the effort needed to justify the use of these materials and to develop models to predict the lifetimes of containers. Here we review the pitting, microbially influenced corrosion (MIC), and corrosion under unsaturated conditions, of titanium. For all these processes, the properties of the passive oxide film are paramount in determining the metal`s resistance to corrosion. A review of these oxide properties is included and the conditions to which the metal must be exposed if localized corrosion is to occur are defined. Since these conditions cannot be achieved under Canadian waste vault conditions, it can be concluded that pitting and MIC will not occur and that corrosion under unsaturated conditions is extremely unlikely. (author) 114 refs., 1 tab., 18 figs.

  8. The resistance of titanium to pitting, microbially induced corrosion and corrosion in unsaturated conditions

    International Nuclear Information System (INIS)

    Shoesmith, D.W.; Ikeda, B.M.

    1997-04-01

    Titanium and its alloys (Grades-2, -12, -16) are candidate materials for Canadian nuclear waste containers on the basis of their apparent immunity to many localized corrosion processes. This simplifies markedly the effort needed to justify the use of these materials and to develop models to predict the lifetimes of containers. Here we review the pitting, microbially influenced corrosion (MIC), and corrosion under unsaturated conditions, of titanium. For all these processes, the properties of the passive oxide film are paramount in determining the metal's resistance to corrosion. A review of these oxide properties is included and the conditions to which the metal must be exposed if localized corrosion is to occur are defined. Since these conditions cannot be achieved under Canadian waste vault conditions, it can be concluded that pitting and MIC will not occur and that corrosion under unsaturated conditions is extremely unlikely. (author)

  9. A STUDY OF CORROSION AND STRESS CORROSION CRACKING OF CARBON STEEL NUCLEAR WASTE STORAGE TANKS

    International Nuclear Information System (INIS)

    BOOMER, K.D.

    2007-01-01

    The Hanford reservation Tank Farms in Washington State has 177 underground storage tanks that contain approximately 50 million gallons of liquid legacy radioactive waste from cold war plutonium production. These tanks will continue to store waste until it is treated and disposed. These nuclear wastes were converted to highly alkaline pH wastes to protect the carbon steel storage tanks from corrosion. However, the carbon steel is still susceptible to localized corrosion and stress corrosion cracking. The waste chemistry varies from tank to tank, and contains various combinations of hydroxide, nitrate, nitrite, chloride, carbonate, aluminate and other species. The effect of each of these species and any synergistic effects on localized corrosion and stress corrosion cracking of carbon steel have been investigated with electrochemical polarization, slow strain rate, and crack growth rate testing. The effect of solution chemistry, pH, temperature and applied potential are all considered and their role in the corrosion behavior will be discussed

  10. Characterization of Corrosion Products on Carbon Steel Exposed to Natural Weathering and to Accelerated Corrosion Tests

    Directory of Open Access Journals (Sweden)

    Renato Altobelli Antunes

    2014-01-01

    Full Text Available The aim of this work was to compare the corrosion products formed on carbon steel plates submitted to atmospheric corrosion in urban and industrial atmospheres with those formed after accelerated corrosion tests. The corrosion products were characterized by X-ray diffraction, Mössbauer spectroscopy, and Raman spectroscopy. The specimens were exposed to natural weathering in both atmospheres for nine months. The morphologies of the corrosion products were evaluated using scanning electron microscopy. The main product found was lepidocrocite. Goethite and magnetite were also found on the corroded specimens but in lower concentrations. The results showed that the accelerated test based on the ASTM B117 procedure presented poor correlation with the atmospheric corrosion tests whereas an alternated fog/dry cycle combined with UV radiation exposure provided better correlation.

  11. Real time corrosion monitoring in atmosphere using automated battery driven corrosion loggers

    DEFF Research Database (Denmark)

    Prosek, T.; Kouril, M.; Hilbert, Lisbeth Rischel

    2008-01-01

    diminishes due to corrosion. Zinc, iron, copper and nickel sensors at several thicknesses are available. Sensitivity of the corrosion measurement varies from 1 to 10 nm depending on the type and thickness of the sensor. Changes in the air corrosivity can be thus detected within hours or even tens of minutes......A logger enabling continuous measurement of corrosion rate of selected metals in indoor and outdoor atmospheres has been developed. Principle of the measurement method is based on the increasing electrical resistance of a measuring element made of the material concerned as its cross-sectional area....... The logger lifetime in medium corrosive environments is designed to be 2 years with full autonomy. Data on the sensor corrosion rate are available any time through GPRS connection or by a non-contact inductive reading without the need of retracting the logger from the exposure site....

  12. Radiation-induced corrosion of stellite-6

    International Nuclear Information System (INIS)

    Behazin, M.; Wren, J.C.

    2012-09-01

    Stellite-6 is a Co-based (58%) alloy that is used for components that require high wear-resistance, such as valve facings and ball bearings in nuclear reactors. In the reactor core, stable 59 Co can be neutron activated by absorption of a neutron to become the radioactive isotope, 60 Co. The 60 Co that is created constitutes a safety hazard for plant workers who have to perform maintenance on the reactor. One of the operational and safety issues in a nuclear reactor is the potential corrosion of Co-based alloys and the introduction of dissolved Co ions into the reactor core. While the corrosion of Stellite-6 has been studied its corrosion behaviour with ionizing radiation present has not been well established. Corrosion kinetics depend on both the aqueous redox conditions and the physical and chemical nature of the alloy surface. The high radiation fields present in a reactor core will cause water to decompose to a range of redox-active species (both highly oxidizing (e.g., ·OH, H 2 O 2 ) and highly reducing (e.g., ·eaq - , ·O 2 - )). These species can significantly influence corrosion kinetics. The effect of γ-radiation on the corrosion of Stellite-6 at pH 10.6 was investigated at temperatures ≤ 150 deg. C. Since the corrosion rate depends strongly on the type of oxide that is present on the material surface, the focus of this corrosion study was to establish the mechanism by which radiolysis affects the nature of the oxide that is present on Stellite-6. The results show that γ-radiation (at a dose rate of 5.5 kGy.h -1 ) increases the corrosion potential on Stellite-6 from -0.7 VSCE to 0.12 VSCE . The corrosion potential without irradiation present is in a potential range where oxidation is limited to the formation of a Co (OH) 2 and CoCr 2 O 4 outer oxide layer on a pre-existing Cr 2 O 3 film. The corrosion potential with irradiation is in a potential range where further oxidation of Co (OH) 2 to CoOOH also occurs. However, since CoOOH is less soluble than

  13. Corrosion control in electric power plants

    International Nuclear Information System (INIS)

    Syrett, B.C.

    1992-01-01

    This paper reports that corrosion of components in power plants costs the US electric power utility industry billions of dollars each year. Through the Electric Power Research Institute's (EPRI) research and development, several approaches have been developed to reduce these huge costs. They include improved materials selection procedures, coatings, cathodic protection, inhibitors, removal of aggressive species from the environment, and on-line corrosion monitoring. In addition, as part of an on-going technology transfer effort, EPRI is developing databases and expert systems that will help utilities obtain corrosion information and guide them in materials selection and failure analysis

  14. Stress corrosion of alloy 600: mechanism proposition

    International Nuclear Information System (INIS)

    Magnin, T.

    1993-01-01

    A fissuring model by stress corrosion based on interactions corrosion-plasticity on the fissure top is proposed to describe the generally intergranular bursting of INCONEL 600 in the PWR. The calculation shows, and some observations check experimentally, that a pseudo intergranular cracking bound to the zigzag micro facets formation along the joints may be so that a completely intergranular bursting. This pseudo intergranular mode makes up a signature of the proposed mechanism. It may be suggested that it may exist one continuity mechanism between the trans and intergranular cracking by stress corrosion of ductile cubic centered faces materials. 2 figs

  15. Corrosion products in power generating systems

    International Nuclear Information System (INIS)

    Lister, D.H.

    1980-06-01

    The important mechanisms of corrosion and corrosion product movement and fouling in the heat transport systems of thermal electric generating stations are reviewed. Oil- and coal-fired boilers are considered, along with nuclear power systems - both direct and indirect cycle. Thus, the fireside and waterside in conventional plants, and the primary coolant and steam-raising circuits in water-cooled reactors, are discussed. Corrosion products in organic- and liquid-metal-cooled reactors also are shown to cause problems if not controlled, while their beneficial effects on the cooling water side of condensers are described. (auth)

  16. Corrosion Characteristics of the SMART Materials

    Energy Technology Data Exchange (ETDEWEB)

    Baek, Jong Hyuk; Jeong, Y. H.; Choi, B. K.; Soh, J. R.; Lee, D. J.; Choi, B. S

    2000-05-01

    This report summarized the corrosion characteristics of the candidate steam generator tubes (PT-7M, ASTM Gr.2, Inconel-600), which are considering as the core materials in SMART. Also, this evaluated the waterchemstry conditions of commercial power plant including the PWR, BWR, WWER, PHWR, RBMK plants in comparison with that of SMART. And this report described that the microstructures of as-received PT-7M, ASTM Gr.2, and Inconel-600 as the candidate materials of fuel cladding and steam generator tubes and characterized the corrosion properties of the materials, which were tested systematically in the conditions of standard, ammonia solution and ammonia nodular to evaluate the corrosion resistance.

  17. Corrosion Characteristics of the SMART Materials

    International Nuclear Information System (INIS)

    Baek, Jong Hyuk; Jeong, Y. H.; Choi, B. K.; Soh, J. R.; Lee, D. J.; Choi, B. S.

    2000-05-01

    This report summarized the corrosion characteristics of the candidate steam generator tubes (PT-7M, ASTM Gr.2, Inconel-600), which are considering as the core materials in SMART. Also, this evaluated the waterchemstry conditions of commercial power plant including the PWR, BWR, WWER, PHWR, RBMK plants in comparison with that of SMART. And this report described that the microstructures of as-received PT-7M, ASTM Gr.2, and Inconel-600 as the candidate materials of fuel cladding and steam generator tubes and characterized the corrosion properties of the materials, which were tested systematically in the conditions of standard, ammonia solution and ammonia nodular to evaluate the corrosion resistance

  18. The Leakage determination on corrosion fretting machine

    International Nuclear Information System (INIS)

    Sriyono; Satmoko, Ari; Hafid, Abdul; Febrianto; Prasetio, Joko; Abtokhi; Sumarno, Edy; Handoyo, Ismu; Hidayati, Nur Rahmah; Histori

    1998-01-01

    Fretting machine is an experimental loop to learn fretting corrosion phenomena wich is caused by loading and vibration. On the steam generator, one of the corrosion process that's occurred, it can be caused by vibration between tubes and bending material. Because of high flow rate inside the tube, the high frequency vibration will appeared so it can make the corrosion on bending material more faster. This process can be simulate by fretting machine. This machine has already damage because of leakage. So it will be repaired by dismantling, radiography testing and redrawing. from the result of radiography, the leakage is caused by cracking on bellows seals of the dynamic main support

  19. In plant corrosion potential monitoring

    International Nuclear Information System (INIS)

    Rosborg, B.; Molander, A.

    1997-01-01

    Examples of in plant redox and corrosion potential monitoring in light water reactors are given. All examples are from reactors in Sweden. The measurements have either been performed in side-stream autoclaves connected to the reactor systems by sampling lines, or in-situ in the system piping itself. Potential monitoring can give quite different results depending upon the experimental method. For environments with small concentrations of oxidants sampling lines can introduce large errors. During such circumstances in-situ measurements are necessary. Electrochemical monitoring is a valuable technique as a complement to conventional water chemistry follow-up in plants. It can be used for water chemistry surveillance and can reveal unintentional and harmful water chemistry transients. (author). 15 figs

  20. In plant corrosion potential monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Rosborg, B; Molander, A [Studsvik Material AB, Nykoeping (Sweden)

    1997-02-01

    Examples of in plant redox and corrosion potential monitoring in light water reactors are given. All examples are from reactors in Sweden. The measurements have either been performed in side-stream autoclaves connected to the reactor systems by sampling lines, or in-situ in the system piping itself. Potential monitoring can give quite different results depending upon the experimental method. For environments with small concentrations of oxidants sampling lines can introduce large errors. During such circumstances in-situ measurements are necessary. Electrochemical monitoring is a valuable technique as a complement to conventional water chemistry follow-up in plants. It can be used for water chemistry surveillance and can reveal unintentional and harmful water chemistry transients. (author). 15 figs.