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Sample records for galvanized steel operating

  1. Recycling galvanized steel: Operating experience and benefits

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A. [Metal Recovery Industries, Inc., East Chicago, IN (United States)

    1993-08-01

    In response to the increase in consumption of galvanized steel for automobiles in the last decade and the problems associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The dezinced ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant to continuously treat loose scrap, with a design capacity of 48,000 tonnes annually, has been in operation in East Chicago, Indiana since early in 1993. The first 450 t of scrap degalvanized in the pilot plant have residual zinc below 0.01% and sodium dragout below 0.01%. Use of degalvanized steel scrap decreases raw materials, environmental compliance, and opportunity costs to steel- and iron-makers. Availability of clean degalvanized scrap may enable integrated steel producers to recycle furnace dusts to the sinter plant and EAF shops to produce flat products without use of high quality scrap alternatives such as DRI, pig iron, or iron carbide. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap. The quantities of zinc available by the year 2000 from prompt and obsolete automotive scrap win approach 25% of zinc consumed in the major automotive production centers of the world. Zinc recycling from galvanized steel scrap, either before or after scrap melting, will have to be implemented.

  2. 77 FR 28404 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2012-05-14

    ...)] Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1\\ developed in the... reason of imports from Mexico of galvanized steel wire, provided for in subheadings 7217.20.30, 7217.20... galvanized steel wire from China and Mexico were sold at LTFV within the meaning of 733(b) of the Act (19 U.S...

  3. 76 FR 29266 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-05-20

    ...)] Galvanized Steel Wire From China and Mexico Determinations On the basis of the record \\1\\ developed in the... reason of imports from China and Mexico of galvanized steel wire, provided for in subheading 7217.20.30... subsidized imports of galvanized steel wire from China and Mexico. Accordingly, effective March 31, 2011, the...

  4. Tropical Weather Resistant Galvanized Steel Coated and Uncoated

    Directory of Open Access Journals (Sweden)

    Suárez-Corrales Xenia Isbel

    2014-01-01

    Full Text Available The corrosion behavior of coated and uncoated galvanized steel products is determined by exposing them to accelerated and natural climatic test. Accelerated tests were carried out in climatic chambers and natural atmospheric test in a marine-coastal station (Cojimar. The influence of tropical humid climate on these products is determined. Adhesion is an important property for a good performance, from the decorative point of view or as an additional protection. The evaluation indicates that 95% of the galvanized steel products show a good corrosion resistance; although 71% of coated galvanized products and 100% of painted galvanized products do not cover the requirements with respect to the mechanical and corrosion protection aspects. For a good efficiency and economic performance of metal mechanical industry, a correct surface treatment and coating application is required. A key point is to increase the quality by improving a better corrosion protective performance respecting uncoated galvanized steel.

  5. 76 FR 21914 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-04-19

    ... INTERNATIONAL TRADE COMMISSION [Investigation Nos. 701-TA-479 and 731-TA-1183-1184 (Preliminary)] Galvanized Steel Wire From China and Mexico AGENCY: United States International Trade Commission. ACTION: Revised schedule for the subject antidumping and countervailing duty investigations. DATES: Effective Date...

  6. Temperature Controlled Laser Joining of Aluminum to Galvanized Steel

    Science.gov (United States)

    Weller, Daniel; Simon, Jörg; Stritt, Peter; Weber, Rudolf; Graf, Thomas; Bezençon, Cyrille; Bassi, Corrado

    Reliable joining of 6000 series aluminum alloy to galvanized steel is a challenge for current manufacturing technologies. To control and limit the formation of brittle intermetallic phases, mixing of both metals in liquid state has to be avoided. It has been shown that laser weld-brazing is a possible process. Thereby the aluminum and zinc layer of the galvanized steel are molten and the steel remains solid during the process. In addition, to avoid zinc degassing, the aluminum melt bath temperature has to be below zinc boiling temperature of 907°C. To meet these requirements a temperature controlled laser process was developed, allowing to join the two materials without flux and filler material. The thickness of the intermetallic layer shows a dependency on the set temperature used to control the process. At optimum set temperature the thickness of intermetallic phases can be limited to about 5 μm. Tensile strengths of the joints of up to 75% of the aluminum base material were achieved.

  7. Finishes for Metals. Paintability of Galvanized Steel, Corrosion Resistance of Metallized Coatings.

    Science.gov (United States)

    Building Research Inst., Inc., Washington, DC.

    Two papers are presented. The first, "Report of the AISI Research Project on the Paintability of Galvanized Steel," was a project aimed at determining optimum procedures for painting bright-spangled galvanized sheet steel products using three classes of trade sales paints--metallic zinc-dust, portland cement-in-oil, and water base emulsion paints.…

  8. Corrosion of bare and galvanized steel in gypsum

    Directory of Open Access Journals (Sweden)

    Gómez, Mercedes

    1988-12-01

    Full Text Available Gypsum is a relatively low-cost building material much abounding in our country. When it is put in contact with steel, it may produce high corrosion rates due to its pH value (close to 7. This work reports the results obtained in studying the corrosion rates of bare and galvanized steel in contact with gypsum and plaster, as well as the influence curing thermal treatment applied to gypsum, enviromental relative humidity and addition of compounds with different natures and purposes may have in such process. In-situ observations, as well as the measurement of the Polarization Resistance and the weight loss have been used as measurement technics. From the results obtained it has been possible to deduce that galvanized steel has better behaviour in dry enviroments than bare steel in the same conditions and moist atmosphere induces proportionally more corrosion in galvanized steel than in bare one. Additions to gypsum do not modified these conclusions, though it may be pointed out that addition of nitrites or lime improves the behaviour of bare steel, while galvanized behaviour is not modified. The addition of lime is not recommended because phenomena of dilated along time expansion may take place.

    El yeso es un material de construcción de relativo bajo coste y que, además, es muy abundante en nuestro país. Debido a su pH cercano a la neutralidad, cuando entra en contacto con el acero, este puede corroerse a elevadas velocidades. En esta comunicación se presentan los resultados de un estudio sobre la velocidad de corrosión del acero desnudo y galvanizado en contacto con yeso y escayola y la influencia que tienen: el tratamiento térmico del curado del yeso, la humedad relativa ambiental y la adición de aditivos de diversa naturaleza y finalidad. Como técnicas de medida se han utilizado la medida de la Resistencia de Polarización y de la pérdida de peso, así como observaciones visuales. De los resultados se puede deducir que en

  9. 77 FR 17427 - Notice of Final Determination of Sales at Less Than Fair Value: Galvanized Steel Wire From Mexico

    Science.gov (United States)

    2012-03-26

    ... Determination of Sales at Less Than Fair Value: Galvanized Steel Wire From Mexico AGENCY: Import Administration... the investigation of sales at less than fair value of galvanized steel wire (galvanized wire) from... Fair Value and Postponement of Final Determination, 76 FR 68422 (November 4, 2011) (Preliminary...

  10. Coating adherence in galvanized steel assessed by acoustic emission wavelet analysis

    International Nuclear Information System (INIS)

    Gallego, Antolino; Gil, Jose F.; Vico, Juan M.; Ruzzante, Jose E.; Piotrkowski, Rosa

    2005-01-01

    Coating-substrate adherence in galvanized steel is evaluated by acoustic emission wavelet analysis in scratch tests on hot-dip galvanized samples. The acoustic emission results are compared with optical and electron microscopy observations in order to understand coating features related to adherence and to establish criteria aimed at improving the manufacture process

  11. The adhesion of epoxy cataphoretic coating on phosphatized hot-dip galvanized steel

    Directory of Open Access Journals (Sweden)

    Bajat Jelena B.

    2006-01-01

    Full Text Available The influence of hot-dip galvanized steel surface pretreatment on the adhesion of epoxy cataphoretic coating was investigated. Phosphate coatings were deposited on hot-dip galvanized steel and the influence of fluoride ions in the phosphating plating bath, as well as the deposition temperature of the plating bath, were investigated. The dry and wet adhesion of epoxy coating were measured by a standard pull-off method. The surface roughness of phosphatized galvanized steel was determined, as well as the wettability of the metal surface by emulsion of the epoxy resin in water. The adhesion of epoxy coatings on phosphatized hot-dip galvanized steel was investigated in 3wt.%NaCI.

  12. Performance evaluation of corrosion inhibitors and galvanized steel in concrete exposure specimens.

    Science.gov (United States)

    1999-01-01

    Corrosion inhibitor admixtures (CIA) and galvanized reinforcing steel (GS) are used for the corrosion protection for reinforced concrete bridges. The results of a 3.5-year evaluation of exposure specimens containing CIA from three different manufactu...

  13. Prevention of Crevice Corrosion of STS 304 Stainless Steel by a Mg-alloy Galvanic Anode

    International Nuclear Information System (INIS)

    Lim, U. J.; Yun, B. D.; Kim, J. J.

    2006-01-01

    Prevention of crevice corrosion was studied for STS 304 stainless steel using a Mg-alloy galvanic anode in solutions with various specific resistivity. The crevice corrosion and corrosion protection characteristics of the steel was investigated by the electrochemical polarization and galvanic corrosion tests. Experimental results show that the crevice corrosion of STS 304 stainless steel does not occur in solutions of high specific resistivity, but it occurs in solutions of low specific resistivity like in solutions with resistivities of 30, 60 and 115 Ω · m. With decreasing specific resistivity of the solution, the electrode potential of STS 304 stainless steel in the crevice is lowered. The potential of STS 304 stainless steel in the crevice after coupling is cathodically polarized more by decreasing specific resistivity indicating that the crevice corrosion of STS 304 stainless steel is prevented by the Mg-alloy galvanic anode

  14. Galvanic Interaction between Chalcopyrite and Pyrite with Low Alloy and High Carbon Chromium Steel Ball

    Directory of Open Access Journals (Sweden)

    Asghar Azizi

    2013-01-01

    Full Text Available This study was aimed to investigate the galvanic interaction between pyrite and chalcopyrite with two types of grinding media (low alloy and high carbon chromium steel ball in grinding of a porphyry copper sulphide ore. Results indicated that injection of different gases into mill altered the oxidation-reduction environment during grinding. High carbon chromium steel ball under nitrogen gas has the lowest galvanic current, and low alloy steel ball under oxygen gas had the highest galvanic current. Also, results showed that the media is anodic relative to pyrite and chalcopyrite, and therefore pyrite or chalcopyrite with a higher rest potential acted as the cathode, whilst the grinding media with a lower rest potential acted as the anode, when they are electrochemically contacted. It was also found that low alloy steel under oxygen produced the highest amount of EDTA extractable iron in the slurry, whilst high carbon chromium steel under nitrogen atmosphere led to the lowest amount.

  15. Thermal stress for all-ceramics rolls used in molten metal to produce stable high quality galvanized steel sheet

    OpenAIRE

    Noda, Nao-Aki; Yamada, Masahiro; Sano, Yoshikazu; Sugiyama, Shigetada; Kobayashi, Shoichi

    2008-01-01

    The zinc coated steel sheet has been mostly used for automobile and other industries because of its high corrosion resistance. This paper deals with the development of new ceramics support roll used for a continuous galvanizing pot to manufacture stable galvanizing steel sheet. Usually stainless steel rolls coated by tungsten carbide are used to support and stabilize the strip in a continuous galvanizing pot, which is filled with molten zinc. However, corrosion and abrasion arise on the roll ...

  16. Pitting, crevice and galvanic corrosion of REX stainless-steel/CoCr orthopedic implant material.

    Science.gov (United States)

    Reclaru, L; Lerf, R; Eschler, P Y; Blatter, A; Meyer, J M

    2002-08-01

    The corrosion behavior of surgical implant CoCr alloy and REX 734 steel has been investigated. The pitting or crevice corrosion potentials have been determined to reach values as high as 500 mV vs. SCE for CoCr and 450 mV vs. SCE for REX 734. The galvanic corrosion behavior of CoCr/REX 734 couples has been evaluated with various electrochemical techniques. The measurement of the corrosion current of the galvanic couple as well as its prediction by applying mixed potential theories on measured potentiodynamic polarization curves revealed low galvanic currents in the range of nanoamperes.

  17. Preventing the embrittling by hydrogen when galvanizing high-grade steel

    Energy Technology Data Exchange (ETDEWEB)

    Paatsch, W.

    1987-09-01

    Galvanic precipitation of a double layer consisting of a dull nickel layer overlaid with a brilliant zinc layer on low-alloyed high-strength steel grades leads to the forming of zinc-nickel alloy layers during the subsequent heat treatment. According to traction tests carried out on high-strength steel grades, as well as to hydrogen permeability tests, this process prevents embrittling by hydrogen which might be caused by galvanic process sequences - and creates a diffusion block at the same time. The alloy layers have an excellent corrosion resistance and temperature stability.

  18. Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

    Directory of Open Access Journals (Sweden)

    Irene Carrillo

    2011-01-01

    Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

  19. Electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy study of the corrosion behaviour of galvanized steel and electroplating steel

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M., E-mail: mlebrini@yahoo.fr [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF-LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF-LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Gengembre, L. [Unite de Catalyse et Chimie du solide UMR 8181 Bat C3, USTL, F-59655, Villeneuve d' Ascq Cedex (France); Fontaine, G. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF-LSPES UMR CNRS 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Lerasle, O.; Genet, N. [TOTAL France, Centre de Recherche de Solaize, Chemin du canal, BP 22, F-69360 Solaize (France)

    2011-02-01

    The efficiency of a formula containing 2-{l_brace}(2-hydroxyethyl)[(4-methyl-1H-1,2,3-benzotriazol-1-yl)methyl] amino{r_brace}ethanol (tolyltriazole) and decanoic acid as corrosion inhibitor for galvanized steel and electroplating steel in aqueous solution have been determined by electrochemical impedance spectroscopy (EIS) techniques. The experimental data obtained from this method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The corrosion behaviour in the presence of different concentration of decanoic acid (DA) in the formula was also investigated by EIS. Results obtained reveal that, the formula is a good inhibitor for galvanized steel and electroplating steel in aqueous solution, the better performance was obtained in the case of galvanized steel. The ability of the inhibitor to be adsorbed on the surface was dependent on the nature of metal. X-ray photoelectron spectroscopy surface analysis with inhibitor shows that it's chemisorbed at the galvanized and electroplating steel/aqueous solution interface.

  20. Electrochemical Corrosion Behavior of Carbon Steel and Hot Dip Galvanized Steel in Simulated Concrete Solution with Different pH Values

    Directory of Open Access Journals (Sweden)

    Wanchen XIE

    2017-08-01

    Full Text Available Hot dip galvanizing technology is now widely used as a method of protection for steel rebars. The corrosion behaviors of Q235 carbon steel and hot galvanized steel in a Ca(OH2 solution with a pH from 10 to 13 was investigated by electrode potential and polarization curves testing. The results indicated that carbon steel and hot galvanized steel were all passivated in a strong alkaline solution. The electrode potential of hot dip galvanized steel was lower than that of carbon steel; thus, hot dip galvanized steel can provide very good anodic protection for carbon steel. However, when the pH value reached 12.5, a polarity reversal occurred under the condition of a certain potential. Hot dip galvanized coating became a cathode, and the corrosion of carbon steel accelerated. The electrochemical behaviors and passivation abilities of hot dip galvanized steel and carbon steel were affected by pH. The higher the pH value was, the more easily they were passivated.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16675

  1. Relation between microstructure and adhesion of hot dip galvanized zinc coatings on dual phase steel

    NARCIS (Netherlands)

    Song, G. M.; Vystavel, T.; De Hosson, J. Th M.; Sloof, W. G.; van der Pers, N.M.

    The microstructure of hot dip galvanized zinc coatings on dual phase steel was investigated by electron microscopy and the coating adhesion characterized by tensile testing. The zinc coating consists of a zinc layer and columnar zeta-FeZn13 particles on top of a thin inhibition layer adjacent to the

  2. Influence of MAO Treatment on the Galvanic Corrosion Between Aluminum Alloy and 316L Steel

    Science.gov (United States)

    Yang, Yuanhang; Gu, Yanhong; Zhang, Lei; Jiao, Xiangdong; Che, Juntie

    2017-12-01

    To slow down the galvanic corrosion of aluminum alloy and 316L stainless steel in subsea water, a micro-arc oxidation (MAO) coating was prepared on the surface of the Al alloy, and no treatment was performed on the surface of the 316L. The surface morphology of MAO-coated Al alloy was evaluated using a scanning electron microscope (SEM) before and after corrosion. A micro-hardness tester was used to measure the micro-hardness. Corrosion behaviors were evaluated by open-circuit potential (OCP), potentiodynamic polarization (PDP) and electrode impedance spectroscopy (EIS) tests in a 3.5 g/L NaCl solution. The results of PDP testing show that the corrosion potential of the MAO-coated galvanic pair was more positive than that of the uncoated galvanic pair and that the corrosion current density was smaller than that of the uncoated galvanic pair. EIS results show that the impedance of the galvanic pair increased after MAO coating. SEM images show that the corrosion damage of the uncoated Al alloy was more severe than that of the MAO-coated one, and the post-corrosion images of the surface of the 316L connected with MAO-coated Al alloy were more compact than those of the 316L connected with uncoated Al alloy. A physical model was developed to discuss the influence of MAO treatment on the galvanic corrosion process and corrosion mechanism.

  3. Galvanic corrosion of Mg-Zr fuel cladding and steel immobilized in Portland cement and geopolymer at early ages

    Science.gov (United States)

    Rooses, Adrien; Lambertin, David; Chartier, David; Frizon, Fabien

    2013-04-01

    Galvanic corrosion behaviour of Mg-Zr alloy fuel cladding and steel has been studied in Ordinary Portland cement and Na-geopolymer. Portland cements implied the worse magnesium corrosion performances due to the negative effects of cement hydrates, grinding agents and gypsum on the galvanic corrosion. Galvanic corrosion in Na-geopolymer paste remains very low. Silicates and fluoride from the geopolymer activation solution significantly improve the corrosion resistance of the magnesium alloy while coupling with a cathode.

  4. Is galvanic corrosion between titanium alloy and stainless steel spinal implants a clinical concern?

    Science.gov (United States)

    Serhan, Hassan; Slivka, Michael; Albert, Todd; Kwak, S Daniel

    2004-01-01

    Surgeons are hesitant to mix components made of differing metal classes for fear of galvanic corrosion complications. However, in vitro studies have failed to show a significant potential for galvanic corrosion between titanium and stainless steel, the two primary metallic alloys used for spinal implants. Galvanic corrosion resulting from metal mixing has not been described in the literature for spinal implant systems. To determine whether galvanic potential significantly affects in vitro corrosion of titanium and stainless steel spinal implant components during cyclical compression bending. Bilateral spinal implant constructs consisting of pedicle screws, slotted connectors, 6.35-mm diameter rods and a transverse rod connector assembled in polyethylene test blocks were tested in vitro. Two constructs had stainless steel rods with mixed stainless steel (SS-SS) and titanium (SS-Ti) components, and two constructs had titanium rods with mixed stainless steel (Ti-SS) and titanium (Ti-Ti) components. Each construct was immersed in phosphate-buffered saline (pH 7.4) at 37 C and tested in cyclic compression bending using a sinusoidal load-controlling function with a peak load of 300 N and a frequency of 5 Hz until a level of 5 million cycles was reached. The samples were then removed and analyzed visually for evidence of corrosion. In addition, scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) were used to evaluate the extent of corrosion at the interconnections. None of the constructs failed during testing. Gross observation of the implant components after disassembly revealed that no corrosion had occurred on the surface of the implants that had not been in contact with another component. The Ti-Ti interfaces showed some minor signs of corrosion only detectable using SEM and EDS. The greatest amount of corrosion occurred at the SS-SS interfaces and was qualitatively less at the SS-Ti and Ti-SS interfaces. The results from this study indicate

  5. Galvanic Liquid Applied Coating System for Protection of Embedded Steel Surfaces from Corrosion

    Science.gov (United States)

    Curran, Joseph; MacDowell, Louis; Voska, N. (Technical Monitor)

    2002-01-01

    The corrosion of reinforcing steel in concrete is an insidious problem for the Kennedy Space Center, government agencies, and the general public. Existing corrosion protection systems on the market are costly, complex, and time-consuming to install, require continuous maintenance and monitoring, and require specialized skills for installation. NASA's galvanic liquid-applied coating offers companies the ability to conveniently protect embedded steel rebar surfaces from corrosion. Liquid-applied inorganic galvanic coating contains one ore more of the following metallic particles: magnesium, zinc, or indium and may contain moisture attracting compounds that facilitate the protection process. The coating is applied to the outer surface of reinforced concrete so that electrical current is established between metallic particles and surfaces of embedded steel rebar; and electric (ionic) current is responsible for providing the necessary cathodic protection for embedded rebar surfaces.

  6. Charging system with galvanic isolation and multiple operating modes

    Science.gov (United States)

    Kajouke, Lateef A.; Perisic, Milun; Ransom, Ray M.

    2013-01-08

    Systems and methods are provided for operating a charging system with galvanic isolation adapted for multiple operating modes. A vehicle charging system comprises a DC interface, an AC interface, a first conversion module coupled to the DC interface, and a second conversion module coupled to the AC interface. An isolation module is coupled between the first conversion module and the second conversion module. The isolation module comprises a transformer and a switching element coupled between the transformer and the second conversion module. The transformer and the switching element are cooperatively configured for a plurality of operating modes, wherein each operating mode of the plurality of operating modes corresponds to a respective turns ratio of the transformer.

  7. Measurement of adhesion properties between topcoat paint and metallized/galvanized steel with surface energy measurement equipment.

    Science.gov (United States)

    2013-09-01

    The objectives of this research project are: (1) Compare the adhesion properties of NEPCOAT-approved topcoat paint over : metallized or galvanized steel. Use surface-energy measuring technique to characterize the wetting properties of the liqui...

  8. Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires.

    Science.gov (United States)

    Gelfi, Marcello; Solazzi, Luigi; Poli, Sandro

    2017-03-06

    This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process. Careful visual inspections showed that the cracks are already present in the coating before the torsion test. In order to explain the origin of these cracks, systematic metallographic investigations were performed by means of optical and scanning electron microscope on both the wires and the rods that have been cold drawn to produce the wire. The chemical composition of the galvanized coatings was evaluated by means of energy dispersive spectroscopy. Micro bidimensional X-ray diffraction experiments were also performed to measure the residual stresses in the galvanized coating. The results showed that the failure is related to two main factors: the relatively high content of silicon in the steel and the unsuitable cooling rate of the rods at the exit from the galvanizing bath. The mechanism proposed to explain the origin of the defects was supported by Finite Elements Methods simulations and verified with in-plant tests. The proper countermeasures were then applied and the problem successfully solved.

  9. Influence of the Manufacturing Process on Defects in the Galvanized Coating of High Carbon Steel Wires

    Directory of Open Access Journals (Sweden)

    Marcello Gelfi

    2017-03-01

    Full Text Available This study is a detailed failure analysis of galvanized high carbon steel wires, which developed coating cracks during the torsion test performed as a quality control at the end of the manufacturing process. Careful visual inspections showed that the cracks are already present in the coating before the torsion test. In order to explain the origin of these cracks, systematic metallographic investigations were performed by means of optical and scanning electron microscope on both the wires and the rods that have been cold drawn to produce the wire. The chemical composition of the galvanized coatings was evaluated by means of energy dispersive spectroscopy. Micro bidimensional X-ray diffraction experiments were also performed to measure the residual stresses in the galvanized coating. The results showed that the failure is related to two main factors: the relatively high content of silicon in the steel and the unsuitable cooling rate of the rods at the exit from the galvanizing bath. The mechanism proposed to explain the origin of the defects was supported by Finite Elements Methods simulations and verified with in-plant tests. The proper countermeasures were then applied and the problem successfully solved.

  10. Zinc toxicity among galvanization workers in the iron and steel industry.

    Science.gov (United States)

    El Safty, Amal; El Mahgoub, Khalid; Helal, Sawsan; Abdel Maksoud, Neveen

    2008-10-01

    Galvanization is the process of coating steel or cast iron pieces with zinc, allowing complete protection against corrosion. The ultimate goal of this work was to assess the effect of occupational exposure to zinc in the galvanization process on different metals in the human body and to detect the association between zinc exposure and its effect on the respiratory system. This study was conducted in 111 subjects in one of the major companies in the iron and steel industry. There were 61 subjects (workers) who were involved in the galvanization process. Fifty adult men were chosen as a matched reference group from other departments of the company. All workers were interviewed using a special questionnaire on occupational history and chest diseases. Ventilatory functions and chest X rays were assessed in all examined workers. Also, complete blood counts were performed, and serum zinc, iron, copper, calcium, and magnesium levels were tested. This study illustrated the relation between zinc exposure in the galvanization process and high zinc levels among exposed workers, which was associated with a high prevalence rate of metal fume fever (MFF) and low blood copper and calcium levels. There was no statistically significant difference between the exposed and control groups with regards to the magnesium level. No long-term effect of metals exposure was detected on ventilatory functions or chest X rays among the exposed workers.

  11. Corrosion control of galvanized steel using a phosphate/calcium ion inhibitor mixture

    International Nuclear Information System (INIS)

    Zin, I.M.; Lyon, S.B.; Pokhmurskii, V.I.

    2003-01-01

    The corrosion inhibition of galvanized steel was studied in artificial acid rain solution using extracts of pigments normally used in organic coatings for corrosion control. It was established that a combination of zinc phosphate/molybdate and calcium ion exchange silica has a significant synergetic anticorrosion effect in the acid rain solution compared to the pigments used alone. Further, the charge transfer resistance of galvanized steel in acid rain solution saturated by the above pigment blend approaches that of strontium chromate in artificial acid rain solution. Use of the pigment blend was found to lead to development of a protective film, which is thought to be a complex mixture of calcium phosphates and zinc phosphate

  12. Relationships between environmental pollution and the corrosion of zinc and galvanized steel

    Energy Technology Data Exchange (ETDEWEB)

    Dreulle, N.; Dreulle, P.

    1973-03-01

    The corrosion spelter and galvanized steel plates used as roofing materials by air pollutants in general, and sulfur dioxide in particular was studied, and measures to be taken to abate corrosion are proposed. In atmosphere containing SO2, zinc is corroded on its surface only through the formation first of insoluble zinc sulfite and then of water-soluble zinc sulfate. A relationship between the site of exposure, the atmospheric SO2 concentration, and the rate of corrosion of zinc was established, and an increase in the rate of corrosion with relative humidity and in precipitation was determined. The rate of corrosion of spelter amounts to about 10 microns per year which corresponds to a life expectancy of about 30 years in industrial polluted air. In urban air, the life expectancy amounts to about 100 years, well over one century in rural areas. The life of galvanized steel plates increases practically linearly with the thickness of the zinc coating. Painting was found highly efficient in abating the corrosion of spelter and galvanized steel. (Air Pollut. Abstr.)

  13. Galvanic Corrosion of Mg-Zr Alloy and Steel or Graphite in Mineral Binders

    Science.gov (United States)

    Lambertin, David; Rooses, Adrien; Frizon, Fabien

    The dismantling of UNGG nuclear reactor generates numerous nuclear wastes such as fuel decanning commonly composed of Mg-Zr alloy. A conditioning strategy consists in encapsulating these wastes into a hydraulic binder in a suitable state for storage. The eventual presence of steel and graphite accompanying the magnesium wastes could imply corrosion by galvanic coupling. This work is an experimental investigation of the galvanic coupling between Mg-Zr alloy and steel or graphite using ZRA electrochemical method in Portland cement or geopolymer pastes. The lowest corrosion activity of magnesium alloy while coupled to graphite or steel cathode has been observed in geopolymer pastes. Indeed, in this binder, an efficient corrosion protection of the magnesium alloy maintains the galvanic current very low during all the hardening process. In geopolymer paste, current densities of anodised Mg-Zr alloy is not dependent of the cathode/anode surface ratio in the range of 0.1 to 5 due to the dominance of the anode resistance.

  14. A Galvanic Sensor for Monitoring the Corrosion Condition of the Concrete Reinforcing Steel: Relationship Between the Galvanic and the Corrosion Currents

    Directory of Open Access Journals (Sweden)

    Elsa Vaz Pereira

    2009-10-01

    Full Text Available This work reports a study carried out on the design and performance of galvanic and polarization resistance sensors to be embedded in concrete systems for permanent monitoring of the corrosion condition of reinforcing steel, aiming to establish a correlation between the galvanic currents, Igal, and the corrosion currents, Icorr, estimated from the polarization resistance, Rp. Sensors have been tested in saturated Ca(OH2 aqueous solutions, under a variety of conditions, simulating the most important parameters that can accelerate the corrosion of concrete reinforcing steel, such as carbonation, ingress of chloride ions, presence or absence of O2. For all the conditions, the influence of temperature (20 to 55 ºC has also been considered. From this study, it could be concluded that the galvanic currents are sensitive to the various parameters following a trend similar to that of the Rp values. A relationship between the galvanic and the corrosion current densities was obtained and the limiting values of the Igal, indicative of the state condition of the reinforcing steel for the designed sensor, were established.

  15. Research on Forming Mechanisms and Controlling Measurements for Surface Light Spot Defects of Galvanizing Steel Coils for Automobile Use

    Science.gov (United States)

    Guangmin, Wei; Haiyan, Sun; Jianqiang, Shi; Lianxuan, Wang; Haihong, Wu

    When producing high surface quality galvanizing steel coils for automobile use, there are always many light spots on the surface since Hansteel CGL No.1 has been put into operation. The defect samples were analyzed by SEM and EDS. The result shows that cause for light spot is not only one. There are more Mn and P in high strength auto sheet, which can result in difficulty to be cleaned off the oxide on the hot rolled coils, so the defects coming. This is why the defects come with high strength auto sheet. When coils galvanized, the defects can't be covered up. To the contrary, the defects will be more obvious when zinc growing on the surface. And sometimes zinc or residue can adhere to work rolls when strips passing through SPM. The deposits then press normal coating. So the light spots come more. When the defect comes from pressing, there is no defect on steel base. The causation is found and measures were taken including high pressure cleaning equipments adopted. Result shows that the defects disappeared.

  16. Effect of hot-dip galvanizing processes on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel

    Science.gov (United States)

    Kuang, Chun-fu; Zheng, Zhi-wang; Wang, Min-li; Xu, Quan; Zhang, Shen-gen

    2017-12-01

    A C-Mn dual-phase steel was soaked at 800°C for 90 s and then either rapidly cooled to 450°C and held for 30 s (process A) or rapidly cooled to 350°C and then reheated to 450°C (process B) to simulate the hot-dip galvanizing process. The influence of the hot-dip galvanizing process on the microstructure and mechanical properties of 600-MPa hot-dip galvanized dual-phase steel (DP600) was investigated using optical microscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and tensile tests. The results showed that, in the case of process A, the microstructure of DP600 was composed of ferrite, martensite, and a small amount of bainite. The granular bainite was formed in the hot-dip galvanizing stage, and martensite islands were formed in the final cooling stage after hot-dip galvanizing. By contrast, in the case of process B, the microstructure of the DP600 was composed of ferrite, martensite, bainite, and cementite. In addition, compared with the yield strength (YS) of the DP600 annealed by process A, that for the DP600 annealed by process B increased by approximately 50 MPa because of the tempering of the martensite formed during rapid cooling. The work-hardening coefficient ( n value) of the DP600 steel annealed by process B clearly decreased because the increase of the YS affected the computation result for the n value. However, the ultimate tensile strength (UTS) and elongation ( A 80) of the DP600 annealed by process B exhibited less variation compared with those of the DP600 annealed by process A. Therefore, DP600 with excellent comprehensive mechanical properties (YS = 362 MPa, UTS = 638 MPa, A 80 = 24.3%, n = 0.17) was obtained via process A.

  17. Cross-Beam Laser Joining of AA 6111 to Galvanized Steel in a Coach Peel Configuration

    Science.gov (United States)

    Yang, Guang; Mohammadpour, Masoud; Yazdian, Nima; Ma, Junjie; Carlson, Blair; Wang, Hui-Ping; Kovacevic, Radovan

    2017-06-01

    Cross-beam laser joining of aluminum alloy 6111 to hot-dip galvanized steel in the coach-peel configuration was investigated with the addition of AA 4047 filler wire. The filler material was not only brazed onto the galvanized steel but also partially fusion-welded with the aluminum panel. Through adjusting the laser power to 3.4 kW, a desirable wetting and spreading of filler wire on both panel surfaces could be achieved, and the thickness of intermetallic layer in the middle section of the interface between the weld bead and steel was less than 2 μm. To better understand the solid/liquid interfacial reaction at the brazing interface, two rotary Gaussian heat source models were introduced to simulate the temperature distribution in the molten pool by using the finite element method. Joint properties were examined in terms of microstructure and mechanical properties. During the tensile test, the fracture of coupons took place at the aluminum side rather than along the interface between the intermetallic layer and steel panel. No failure occurred during the three-point bending test.

  18. Anodized titanium and stainless steel in contact with CFRP: an electrochemical approach considering galvanic corrosion.

    Science.gov (United States)

    Mueller, Yves; Tognini, Roger; Mayer, Joerg; Virtanen, Sannakaisa

    2007-09-15

    The combination of different materials in an implant gives the opportunity to better fulfill the requirements that are needed to improve the healing process. However, using different materials increases the risk of galvanic coupling corrosion. In this study, coupling effects of gold-anodized titanium, stainless steel for biomedical applications, carbon fiber reinforced polyetheretherketone (CFRP), and CFRP containing tantalum fibers are investigated electrochemically and by long-term immersion experiments in simulated body fluid (SBF). Potentiodynamic polarization experiments (i/E curves) and electrochemical impedance spectroscopy (EIS) of the separated materials showed a passive behavior of the metallic samples. Anodized titanium showed no corrosion attacks, whereas stainless steel is highly susceptibility for localized corrosion. On the other side, an active dissolution behavior of both of the CFRPs in the given environment could be determined, leading to delaminating of the carbon fibers from the matrix. Long-term immersion experiments were carried out using a set-up especially developed to simulate coupling conditions of a point contact fixator system (PC-Fix) in a biological environment. Electrochemical data were acquired in situ during the whole immersion time. The results of the immersion experiments correlate with the findings of the electrochemical investigation. Localized corrosion attacks were found on stainless steel, whereas anodized titanium showed no corrosion attacks. No significant differences between the two CFRP types could be found. Galvanic coupling corrosion in combination with crevice conditions and possible corrosion mechanisms are discussed. Copyright 2007 Wiley Periodicals, Inc.

  19. Comparison of Metallurgical and Ultrasonic Inspections of Galvanized Steel Resistance Spot Welds

    International Nuclear Information System (INIS)

    Potter, Timothy J.; Ghaffari, Bita; Mozurkewich, George; Reverdy, Frederic; Hopkins, Deborah

    2006-01-01

    Metallurgical examination of galvanized steel resistance spot welds was used to gauge the capabilities of two ultrasonic, non-destructive, scanning techniques. One method utilized the amplitude of the echo from the weld faying surface, while the other used the spectral content of the echo train to map the fused area. The specimens were subsequently sectioned and etched, to distinguish the fused, zinc-brazed, and non-fused areas. The spectral maps better matched the metallurgical maps, while the interface-amplitude method consistently overestimated the weld size

  20. Importance of temperature, pH, and boric acid concentration on rates of hydrogen production from galvanized steel corrosion

    International Nuclear Information System (INIS)

    Loyola, V.M.

    1982-01-01

    One of the known sources of hydrogen gas within a nuclear plant containment building during a LOCA is the high temperature corrosion of galvanized steel yielding hydrogen gas. The importance of this source of hydrogen will vary depending on the severity of the accident. In an accident which resulted in core degradation, for example, the major source of hydrogen would probably be the metal-water reaction of the zircaloy cladding, and the corrosion of galvanized steel would then become a relatively minor source of hydrogen. However, in an accident in which core degradation is avoided or limited to minor damage, the corrosion of galvanized steel, and presumably of other materials as well, would then become a major contributor to the buildup of hydrogen within containment. The purpose of this paper is to present the overall effects of temperature, pH, and boric acid concentration on the rate of hydrogen generation over a broad range of each parameter

  1. Characterization of organic-inorganic hybrid coatings for corrosion protection of galvanized steel and electroplated ZnFe steel

    Directory of Open Access Journals (Sweden)

    Maria Eliziane Pires de Souza

    2006-03-01

    Full Text Available The development of hybrids materials has been extensively investigated in recent years. The combination of a wide variety of compositions and production processes had permitted the use of these materials in different applications like coatings for corrosion protection of metals. In this work organic-inorganic hybrid materials have been prepared from the hydrolysis of tetraethylorthosilicate and silanol-terminated polidymetilmetoxysilane using a sol-gel process. These materials have been applied on galvanized steel and on steel electroplated with a ZnFe. In order to evaluate the degradation behavior of these coatings, electrochemical techniques (Electrochemical Impedance Spectroscopy and Potentiodynamic Polarization were used. EIS data was fitted to an equivalent circuit from which the electrochemical parameters were obtained. Results show a good protective character of the hybrid films, when compared with uncovered specimens. The overall performance of the coating systems appears to be highly dependent on the kind of metallic coating applied to the steel.

  2. Galvanic deposition and characterization of brushite/hydroxyapatite coatings on 316L stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Blanda, Giuseppe [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Brucato, Valerio; Pavia, Francesco Carfì; Greco, Silvia [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Piazza, Salvatore; Sunseri, Carmelo [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy); Inguanta, Rosalinda, E-mail: rosalinda.inguanta@unipa.it [Laboratorio di Chimica Fisica Applicata, Dipartimento di Ingegneria Chimica Gestionale Informatica Meccanica, Università di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

    2016-07-01

    In this work, brushite and brushite/hydroxyapatite (BS, CaHPO{sub 4}·H{sub 2}O; HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) coatings were deposited on 316L stainless steel (316LSS) from a solution containing Ca(NO{sub 3}){sub 2}·4H{sub 2}O and NH{sub 4}H{sub 2}PO{sub 4} by a displacement reaction based on a galvanic contact, where zinc acts as sacrificial anode. Driving force for the cementation reaction arises from the difference in the electrochemical standard potentials of two different metallic materials (316LSS and Zn) immersed in an electrolyte, so forming a galvanic contact leading to the deposition of BS/HA on nobler metal. We found that temperature and deposition time affect coating features (morphology, structure, and composition). Deposits were characterized by means of several techniques. The morphology was investigated by scanning electron microscopy, the elemental composition was obtained by X-ray energy dispersive spectroscopy, whilst the structure was identified by Raman spectroscopy and X-ray diffraction. BS was deposited at all investigated temperatures covering the 316LSS surface. At low and moderate temperature, BS coatings were compact, uniform and with good crystalline degree. On BS layers, HA crystals were obtained at 50 °C for all deposition times, while at 25 °C, its presence was revealed only after long deposition time. Electrochemical studies show remarkable improvement in corrosion resistance. - Highlights: • Brushite/hydroxyapatite coatings were obtained by a galvanic deposition method. • Galvanic deposition is simple and cheap and does not require external power supply. • Temperature is a key parameter to control composition and morphology of coatings. • Ca/P ratio changes with deposition time, from about 1 up to an optimum value of 1.7. • Compact and adherent layer covering substrate surface were obtained on 316LSS.

  3. Numerical analysis of weld pool for galvanized steel with lap joint in GTAW

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hunchul; Park, Kyungbae; Kim, Yougjun; Cho, Jungho [Chungbuk National University, Cheongju (Korea, Republic of); Kim, Dong-Yoon; Kang, Moon-Jin [Korea Institute of Industrial Technology, Incheon (Korea, Republic of)

    2017-06-15

    Galvanized steel is widely used and its demand is growing in automotive industry due to high quality requirement for corrosion resistance. Although there are a lot of demands on using galvanized steel as automotive parts especially for outer body, it has a grave flaw in its welding process. The difficulty is low weldability due to various defects such as porosities and blow holes in weldment, which occurred during welding. A solution to prevent these defects is using hybrid welding process, with two more welding processes. One of the hybrid solutions is using Gas tungsten arc welding (GTAW) as leading position in order to remove the zinc (Zn) coating on the surface before the followed practical fusion welding process. In this research, a numerical analysis model which can predict the eliminated Zn coated layers and the area of Fusion zone (FZ). Developed numerical analysis model was validated through comparing experiment to simulation. Basically, arc heat flux, arc pressure, electromagnetic force and Marangoni flow were employed as the boundary conditions and body force terms. Governing equations such as the continuity, momentum, Volume of fluid (VOF) and energy equations were adopted as usual. In addition to previous model, concentrated arc heat flux and contact thermal conductance models are newly suggested and showed successful result. They are adopted to realize edge concentrated arc and interfacial thermal conductance in lap joint fillet arc welding. Developed numerical analysis model successfully simulated the weld pool and temperature profile therefore the predicted Zn removed area considerably coincided with experimental result.

  4. Laser fusion-brazing of aluminum alloy to galvanized steel with pure Al filler powder

    Science.gov (United States)

    Liu, Jia; Jiang, Shichun; Shi, Yan; Kuang, Yulin; Huang, Genzhe; Zhang, Hong

    2015-03-01

    The fusion-brazing connection of the dissimilar metal 5052 aluminum alloy/ST07Z steel was achieved by using the Nd:YAG laser with pure Al filler powder, and the effects of the laser power and powder feeding speed on the formation and mechanical properties of the resultant joints were investigated. The experimental results show that melting-brazing connection of 5052 aluminum alloy/galvanized steel can be successfully achieved, and the zinc plating layer has played the role of flux, assuring the brazing properties. The intermetallic compound layer was generated on the welded brazing interface. The joint exhibited a shear strength of 174 N/mm if the thickness of the intermetallic layer at the interface is about 6-7 μm.

  5. 77 FR 17430 - Galvanized Steel Wire From the People's Republic of China: Final Determination of Sales at Less...

    Science.gov (United States)

    2012-03-26

    ... the People's Republic of China: Final Determination of Sales at Less Than Fair Value AGENCY: Import... Determination of sales at less than fair value (``LTFV'') in the antidumping investigation of galvanized steel... Determination of Sales at Less Than Fair Value, 76 FR 73589 (November 29, 2011) (``Amended Preliminary...

  6. REMOVING ZINC FROM GALVANIZED STEEL SCRAP TO FEASIBLE THE BOF SLUDGE RECYCLING

    Directory of Open Access Journals (Sweden)

    Mônica Marques Caetano de Lima

    2013-06-01

    Full Text Available Galvanized steel scraps generated at Usiminas Ipatinga are recycled in BOF converters. Although they are noble products, they contain a significant quantity of zinc that escapes from the bath due to its high vapor pressure and is captured by the gas control system, appearing in BOF sludge. As BOF sludge contains high iron content, it could be recycled to the process, but due to its zinc content, it is disposed in landfills. For this reason, this study aimed to treat these scraps to remove zinc layer using a thermal treatment process. The samples were fed to a rotative furnace in an inert ambient. It was tested the hot dip galvanized and eletrogalvanized scraps, varying the zinc coating weight between 20g/m2 and 150g/m2, temperature between 700°C and 900°C and time between 3 minutes and 10 minutes. Considering these conditions, it is verified that more than 70% of the zinc layer is removed at 700°C, in 10 minutes. Dust captured is about 60% of metallic zinc and 40% as zinc oxide. Based on these results, the recycling of BOF sludge can be feasible to the ironmaking process.

  7. Moessbauer Studies of Corrosion Products Developed in Prohesion Test over Galvanized Steel Sheets

    International Nuclear Information System (INIS)

    Zapponi, M.; Perez, T.; Ramos, C.; Saragovi, C.

    2003-01-01

    Precoated galvanized steel sheets were submitted to Prohesion test (PT) and to outdoor marine exposure test (OT). The corrosion products were different in both cases. Goethite, lepidocrocite, pyrite and magnetite were found in the Prohesion test samples; the presence of akaganeite cannot be discarded. Surprisingly greigite was detected in these samples, suggesting in addition a located microbiological corrosion process. On the other hand, goethite, lepidocrocite, magnetite, akaganeite and silicates were found in outdoor exposure samples. This study allows the conclusion that in the Prohesion G-85 test the corrosion mechanism is different from that in the marine atmosphere for the analyzed samples and could not be used to predict the performance of this type of outdoor exposed materials.

  8. Effect of zinc crystals size on galvanized steel deformation and electrochemical behavior

    Directory of Open Access Journals (Sweden)

    José Daniel Culcasi

    2009-09-01

    Full Text Available Hot-dip galvanized steel sheets with different spangle sizes were deformed by means of rolling and tension. The change of preferential crystallographic orientation and of superficial characteristics due to the deformation was analyzed by means of both X-rays diffraction and optical and scanning electronic microscopy. A correlation between such changes and the involving deformation modes was intended to be done and the spangle size influence on these modes was studied. Coating reactivity change due to the deformation was investigated by means of quasi-steady DC electrochemical tests. The results allow to infer that, in great spangle samples, the main deformation mechanism is twinning whereas in small spangle ones, pyramidal slip systems happen as well. The increase of the reactivity with the deformation is greater in tension than in rolling and it is more important in small than in great spangle samples.

  9. Effect of Temperature on the Galvanic Corrosion of Cu-Ni Alloy/High Strength Steel in Seawater

    Directory of Open Access Journals (Sweden)

    Wang Chun Li

    2016-01-01

    Full Text Available The galvanic corrosion behavior of Cu-Ni Alloy(B10/high strength steel (921A has been studied using a zero-resistance ammeter (ZRA in seawater at different temperatures. As well as it was systemically investigated by weight loss measurements, electrochemical methods and scanning electron microscope.Results showed 921A acts as the anode and B10 act as the cathodes. The effect of temperature on the galvanic corrosion is important, the corrosion rate became higher with the temperature increased.

  10. Stainless and Galvanized Steel, Hydrophobic Admixture and Flexible Polymer-Cement Coating Compared in Increasing Durability of Reinforced Concrete Structures

    Science.gov (United States)

    Tittarelli, Francesca; Giosuè, Chiara; Mobili, Alessandra

    2017-08-01

    The use of stainless or galvanized steel reinforcements, a hydrophobic admixture or a flexible polymer-cement coating were compared as methods to improve the corrosion resistance of sound or cracked reinforced concrete specimens exposed to chloride rich solutions. The results show that in full immersion condition, negligible corrosion rates were detected in all cracked specimens, except those treated with the flexible polymer-cement mortar as preventive method against corrosion and the hydrophobic concrete specimens. High corrosion rates were measured in all cracked specimens exposed to wet-dry cycles, except for those reinforced with stainless steel, those treated with the flexible polymer-cement coating as restorative method against reinforcement corrosion and for hydrophobic concrete specimens reinforced with galvanized steel reinforcements.

  11. Effect of dual laser beam on dissimilar welding-brazing of aluminum to galvanized steel

    Science.gov (United States)

    Mohammadpour, Masoud; Yazdian, Nima; Yang, Guang; Wang, Hui-Ping; Carlson, Blair; Kovacevic, Radovan

    2018-01-01

    In this investigation, the joining of two types of galvanized steel and Al6022 aluminum alloy in a coach peel configuration was carried out using a laser welding-brazing process in dual-beam mode. The feasibility of this method to obtain a sound and uniform brazed bead with high surface quality at a high welding speed was investigated by employing AlSi12 as a consumable material. The effects of alloying elements on the thickness of intermetallic compound (IMC) produced at the interface of steel and aluminum, surface roughness, edge straightness and the tensile strength of the resultant joint were studied. The comprehensive study was conducted on the microstructure of joints by means of a scanning electron microscopy and EDS. Results showed that a dual-beam laser shape and high scanning speed could control the thickness of IMC as thin as 3 μm and alter the failure location from the steel-brazed interface toward the Al-brazed interface. The numerical simulation of thermal regime was conducted by the Finite Element Method (FEM), and simulation results were validated through comparative experimental data. FEM thermal modeling evidenced that the peak temperatures at the Al-steel interface were around the critical temperature range of 700-900 °C that is required for the highest growth rate of IMC. However, the time duration that the molten pool was placed inside this temperature range was less than 1 s, and this duration was too short for diffusion-control based IMC growth.

  12. Kinetics of atmospheric corrosion of mild steel, zinc, galvanized iron and aluminium at 10 exposure stations in India

    International Nuclear Information System (INIS)

    Natesan, M.; Venkatachari, G.; Palaniswamy, N.

    2006-01-01

    As a part of updating Corrosion Map of India project, atmospheric corrosion behaviour of commercially available engineering materials such as mild steel, galvanized iron, zinc and aluminium metals was studied in marine, industrial, urban, and rural environments by weight loss method at 10 exposure stations in India over a period of 5 years. The results of these studies demonstrated that galvanized iron, zinc and aluminium metals were several times more durable than mild steel. Compared to galvanized iron and zinc, aluminium provided superior protection in industrial and marine environment except at Mormugao Port Trust (MPT). It also offered much better resistance to corrosion in rural environments. At certain places, galvanized iron proved to be more durable than aluminium. The results obeyed well with the empirical kinetics equation of the form C = Kt n , where K and C are the corrosion losses in μm after 1 and 't' years of the exposure, respectively, and 'n' is a constant. Based on 'n' values, the corrosion mechanisms of these metals are predicted. The corrosion products formed on the metal samples in Chennai marine atmosphere were identified by X-ray diffraction analysis

  13. Hybrid laser-arc welding of galvanized high-strength steels in a gap-free lap-joint configuration

    Science.gov (United States)

    Yang, Shanglu

    In order to meet the industry demands for increased fuel efficiency and enhanced mechanical and structural performance of vehicles as well as provided excellent corrosion resistance, more and more galvanized advanced high-strength steels (AHSS) have been used to fabricate automobile parts such as panels, bumpers, and front rails. The automotive industry has shown tremendous interest in using laser welding to join galvanized dual phase steels because of lower heat input and higher welding speed. However, the laser welding process tends to become dramatically unstable in the presence of highly pressurized zinc vapor because of the low boiling point of zinc, around 906°C, compared to higher melting point of steel, over 1500°C. A large number of spatters are produced by expelling the liquid metal from the molten pool by the pressurized zinc vapor. Different weld defects such as blowholes and porosities appear in the welds. So far, limited information has been reported on welding of galvanized high strength dual-phase steels in a gap-free lap joint configuration. There is no open literature on the successful attainment of defect-free welds from the laser or hybrid welding of galvanized high-strength steels. To address the significant industry demand, in this study, different welding techniques and monitoring methods are used to study the features of the welding process of galvanized DP steels in a gap-free lap joint configuration. The current research covers: (i) a feasibility study on the welding of galvanized DP 980 steels in a lap joint configuration using gas tungsten arc welding (GTAW), laser welding, hybrid laser/arc welding with the common molten pool, laser welding with the assistance of GTAW preheating source and hybrid laser-variable polarity gas tungsten arc welding (Laser-VPGTAW) techniques (Chapter 2-4); (ii) a welding process monitoring of the welding techniques including the use of machine vision and acoustic emission technique (Chapter 5); (iii

  14. Evaluation of Corrosion Behavior of Galvanized Steel Treated with Conventional Conversion Coatings and a Chromate-Free Organic Inhibitor

    Directory of Open Access Journals (Sweden)

    Laura A. Hernandez-Alvarado

    2012-01-01

    Full Text Available Conventional weight loss tests and both DC and AC electrochemical techniques were used to study if an organic inhibitor containing an alkanolamine salt of a polycarboxylic acid can substitute toxic coatings as chromating and certain phosphating procedures in the protection of galvanized steel. The electrolyte used was a 0.5 M aerated NaCl solution. All tests gave concordant results, indicating that the chromate-free organic inhibitor does protect galvanized steel in this environment, even though the provided protection was less than that of the chromate conversion coating. It was observed that, after a moderate initial attack, the corrosion rate diminishes due to the appearance and growth of passivating corrosion products layers, mainly constituted by zinc hydroxychloride (Zn5(OH8CI2⋅H2O and two varieties of zinc hydroxide, among other crystalline compounds.

  15. Utilization of galvanized steel transmission lines for small electric power plants; Utilizacion de conductores de hierro galvanizado en lineas de transmission para pequenas centrales

    Energy Technology Data Exchange (ETDEWEB)

    Trejos D, Roberto [Universidad de Costa Rica, San Jose (Costa Rica). Facultad de Ingenieria

    1995-07-01

    This paper analyses the possibility to use galvanized steel cable instead of the traditional aluminium cable steel reinforced (ACSR), in very short transmission lines to be used in small scale hydroelectrical plants projects. It begins with the description of electrical and mechanical characteristics of iron based electrical conductors, followed by the comparison with ACSR conductors. Finally, a description of a practical case is made, in which steel cables have been used. The paper arrives to the conclusion that, in spite of their deficient electrical characteristics, due to their low cost, galvanizes steel conductors can be profitable to use in some cases. (author)

  16. An experimental study on fracture toughness of resistance spot welded galvanized and ungalvanized DP 450 steel sheets used in automotive body

    Energy Technology Data Exchange (ETDEWEB)

    Sevim, I.

    2016-07-01

    The purpose of this study is to determine fracture toughness of Resistance Spot Welded (RSW) Dual Phase (DP) steels. RSW of galvanized and ungalvanized DP 450 steel sheets was carried out on spot welding machine. Fracture toughness of RSW joints of galvanized and ungalvanized DP 450 steel sheets was calculated from tensile-shear tests. New empirical equations were developed using Least Squares Method (LSM) between energy release rate, fracture toughness and critical crack size depending on the relationship between hardness and fracture toughness values. Results indicated that fracture toughness of joints welded by using RSW increased exponentially while the hardness decreased. In addition, fracture toughness and energy release rate of RSW galvanized DP 450 steel sheets were lower compared to RSW ungalvanized DP 450 steel sheets which had approximately the same hardness. (Author)

  17. The effect of zinc thickness on corrosion film breakdown of Colombian galvanized steel

    Science.gov (United States)

    Sandoval-Amador, A.; E Torres Ramirez, J.; Cabrales-Villamizar, P. A.; Laverde Cataño, D.; Y Peña-Ballesteros, D.

    2017-12-01

    This work studies the corrosion behaviour of Colombian galvanized steel in solutions of chloride and sulphate ions. The effect of the thickness and exposure time on the film’s breakdown susceptibility and protectiveness of the corrosion products were studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy. The corrosion products were analysed using SEM-EDS and XRD. The samples with a higher thickness level in the zinc film (Z180) have the lowest corrosion rate. In this case, one of the products that was formed by the chemical reactions that occurred was Zinc hydroxide, which exhibits a passive behaviour as observed in the Pourbaix curves of the obtained potentials and in how the different Ph levels of the solutions worked. The sheets with the highest thickness (Z180) had the best performance, since at the end of the study they showed the least amount of damage on the surface of the zinc layer. This is because the thickness of the zinc layer favours the formation of simonkolleite, which is the corrosion product that protects the material under the conditions of the study.

  18. An environmentally acceptable primer for galvanized steel: Formulation and evaluation by SVET

    Energy Technology Data Exchange (ETDEWEB)

    Simoes, A.M.P., E-mail: alda.simoes@ist.utl.p [CIDEPINT - Centro de Investigacion y Desarrollo en Tecnologia de Pinturas (CIC-CONICET), Calle 52 e/121 y 122, 1900 La Plata (Argentina); TULisbon, Instituto Superior Tecnico, DEQB, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Carbonari, R.O.; Di Sarli, A.R.; Amo, B. del [CIDEPINT - Centro de Investigacion y Desarrollo en Tecnologia de Pinturas (CIC-CONICET), Calle 52 e/121 y 122, 1900 La Plata (Argentina); TULisbon, Instituto Superior Tecnico, DEQB, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Romagnoli, R., E-mail: estelectro@cidepint.gov.a [CIDEPINT - Centro de Investigacion y Desarrollo en Tecnologia de Pinturas (CIC-CONICET), Calle 52 e/121 y 122, 1900 La Plata (Argentina); TULisbon, Instituto Superior Tecnico, DEQB, Av. Rovisco Pais, 1049-001 Lisboa (Portugal)

    2011-01-15

    Research highlights: {yields} Chromates can be replaced successfully by aluminium phosphosilicate in paint systems. {yields} The solvents of the primer are eco-friendly ones. {yields} The primer adheres on galvanized steel and allows top-coating. {yields} The binder of the primer is compatible with other binders for top-coating. - Abstract: The object of this paper was to formulate a two-pack wash primer employing aluminium phosphosilicate as active anticorrosive pigment instead of basic zinc chromate. The anticorrosive action of the primer was evaluated by the polarization technique and the scanning vibrating electrode technique (SVET). The exposed surface was then examined by scanning electron microscopy (SEM) and the surface composition determined by energy dispersive X-ray (EDX) analysis. The primer was finally integrated in a complete paint scheme whose anticorrosive performance was evaluated by the salt spray chamber and electrochemical impedance spectroscopy. The adhesion of the primer plus a painting system was also evaluated by standard ASTM D 3359-90 test method. The wash primer pigmented with zinc chromate was used as reference. Results indicated that basic zinc chromate could be replaced by the more eco-friendly wash-primer containing aluminium phosphosilicate.

  19. Galvanic Liquid Applied Coating System For Protection of Embedded Steel Surfaces from Corrosion

    Science.gov (United States)

    Curran, Joseph; Curran, Jerome; Voska, N. (Technical Monitor)

    2002-01-01

    Corrosion of reinforcing steel in concrete is an insidious problem facing Kennedy Space Center (KSC), other Government Agencies, and the general public. These problems include KSC launch support structures, highway bridge infrastructure, and building structures such as condominium balconies. Due to these problems, the development of a Galvanic Liquid Applied Coating System would be a breakthrough technology having great commercial value for the following industries: Transportation, Infrastructure, Marine Infrastructure, Civil Engineering, and the Construction Industry. This sacrificial coating system consists of a paint matrix that may include metallic components, conducting agents, and moisture attractors. Similar systems have been used in the past with varying degrees of success. These systems have no proven history of effectiveness over the long term. In addition, these types of systems have had limited success overcoming the initial resistance between the concrete/coating interface. The coating developed at KSC incorporates methods proven to overcome the barriers that previous systems could not achieve. Successful development and continued optimization of this breakthrough system would produce great interest in NASA/KSC for corrosion engineering technology and problem solutions. Commercial patents on this technology would enhance KSC's ability to attract industry partners for similar corrosion control applications.

  20. Contribution to Kinetics of Formation of White Rust on Galvanized Steel

    International Nuclear Information System (INIS)

    Han, D. J.; Pyun, Su Il; Hahn, Y. D.

    1981-01-01

    Kinetics of formation of white rust on galvanized steel coated with various chromating solutions was studied. White rust occurs as a mixture of zinc oxide and zinc hydroxide. White rust formation rate was measured with a salt spray test as related to Cr 3+ ion amount, ratio of Cr 3+ to Cr 6+ ion(by weight) and surface roughness of the chromate film. Incubation time of white rust formation increased as the ratio of Cr 3+ to Cr 6+ ion in the chromate film increased. White rust propagation rate decreased as the amount of Cr 3+ ion increased. Surface roughness had no detectable relationship with incubation time and white rust propagation rate. Experimental results showed that kinetics of white rust formation was as follows: chromate film consists of insoluble Cr 3+ ion and soluble Cr 6+ ion, the latter act: as a corrosion inhibitor. Leaching rate of Cr 6+ ion from the film decreases with an increase of the ratio of Cr 3+ to Cr 6+ ion in the chromate film. When Cr 6+ ion is leached from the film, a bare zine layer is exposed to air and discontinuities occur in the film where white rust formation is initiated. Further white rust formation occurs due to destruction of the chromate film by chlorine ion. It is concluded that two stages of white rust formation are present and can be ascribed to Cr 6+ ion leaching and destruction of the chromate film by chlorine ion

  1. Effect of Annealing Temperature on Microstructure and Mechanical Properties of Hot-Dip Galvanizing DP600 Steel

    Science.gov (United States)

    Hai-yan, Sun; Zhi-li, Liu; Yang, Xu; Jian-qiang, Shi; Lian-xuan, Wang

    Hot-dip galvanizing dual phase steel DP600 steel grade with low Si was produced by steel plant and experiments by simulating galvanizing thermal history. The microstructure was observed and analyzed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effect of different annealing temperatures on the microstructure and mechanical properties of dual-phase steel was also discussed. The experimental results show that the dual-phase steel possesses excellent strength and elongation that match EN10346 600MPa standards. The microstructure is ferrite and martensite. TEM micrograph shows that white ferrite with black martensite islands inlay with a diameter of around 1um and the content of 14 18%. The volume will expand and phase changing take the form of shear transformation when ferrite converted to martensite. So there are high density dislocations in ferrite crystalline grain near martensite. The martensite content growing will be obvious along with annealing temperature going up. But the tendency will be weak when temperature high.

  2. Improved Corrosion and Abrasion Resistance of Organic-Inorganic Composite Coated Electro-galvanized Steels for Digital TV Panels

    International Nuclear Information System (INIS)

    Jo, Du-Hwan; Noh, Sang-Geol; Park, Jong-Tae; Kang, Choon-Ho

    2015-01-01

    Recently, household electronic industries require environmentally-friendly and highly functional steels in order to enhance the quality of human life. Customers especially require both excellent corrosion and abrasion resistant anti-fingerprint steels for digital TV panels. Thus POSCO has developed new functional electro-galvanized steels, which have double coated layers with organic-inorganic composites on the zinc surface of the steel for usage as the bottom chassis panel of TVs. The inorganic solution for the bottom layer consists of inorganic phosphate, magnesium, and zirconium compounds with a small amount of epoxy binder, and affords both improved adhesion properties by chemical conversion reactions and corrosion resistance due to a self-healing effect. The composite solution for the top layer was prepared by fine dispersion of organic-inorganic ingredients that consist of a urethane modified polyacrylate polymer, hardener, silica sol and a titanium complex inhibitor in aqueous media. Both composite solutions were coated on the steel surface by using a roll coater and then cured through an induction furnace in the electro-galvanizing line. New anti-fingerprint steel was evaluated for quality performance through such procedures as the salt spray test for corrosion resistance, tribological test for abrasion resistance, and conductivity test for surface electric conductance regarding to both types of polymer resin and coating weight of composite solution. New composite coated anti-fingerprint steels afford both better corrosion resistance and abrasion properties compared to conventional anti-fingerprint steel that mainly consists of acrylate polymers. Detailed discussions of both composite solutions and experimental results suggest that urethane modifications of acrylate polymers of composite solutions play a key role in enhanced quality performances

  3. Characterization of Sludge from the Process of Steel Tubes Chemical Treatment for Hot Galvanizing

    Directory of Open Access Journals (Sweden)

    Sofilić, U.

    2009-10-01

    Full Text Available Inadequate industrial waste management in Croatia is reflected in the non-sanitary waste disposal, low recycling levels, negligible share of waste processing technologies, insufficient control of its flows, etc.Generated industrial wastes are most frequently disposed of at producers’ own, mostly illegal landfills. There are many such landfills on the Croatian territory, and the disposed types of waste often include those that can be hazardous and represent a considerable source of environmental pollution.Past waste management in all industrial branches can be characterized in this way, which at the same time may result in the harmful impact on human health and the environment. It also represents economic loss due to low utilisation of material and energy potential of some industrial wastes. The metallurgical industry collects its production waste separately. Only a part of the generated waste is returned to the production process and some waste is occasionally used by other industries as secondary raw materials, but the largest part of it ends at producers' own landfills on site. Hazardous wastes (dust containing heavy metals, waste oils etc. are mostly disposed of in a controlled and lawful manner. Past handling of metallurgical waste was unacceptable both from the environmental and economic point of view. Therefore a systematic resolving of this important issue was initiated at the beginning of this decade. Sisak Steelworks galvanized steel pipes in the hot-dip galvanizing procedure by immersing in molten zinc. Between 1970 and 2000 Sisak Steelworks produced approximately 900 000 tonnes of galvanized pipes this way and generated around 70 000 m3 of neutralisation sludge, which was subsequently disposed of in the landfill on site. The paper presents the results of examination of physical-chemical properties of neutralisation sludge generated as waste material in the process of neutralisation of waste sulphate acid bath used in Sisak

  4. Atmospheric Corrosion of Painted Galvanized and 55%Al-Zn Steel Sheets: Results of 12 Years of Exposure

    Directory of Open Access Journals (Sweden)

    C. I. Elsner

    2012-01-01

    Full Text Available Zinc or 55%Al-Zn alloy-coated steel sheets, either bare or covered by different painting systems, have been exposed for 12 years to the action of the urban atmosphere at the CIDEPINT station located in La Plata (34° 50′ South, 57° 53′, West, province of Buenos Aires, Argentina. The samples exposed surface was evaluated through periodical visual inspections, standardized adhesion tests, and electrochemical impedance measurements. The ambient variables monitored were average annual rains and temperatures, time of wetness, sulphur and chloride concentration, relative humidity, and speed and direction of the winds. It was found that in this atmosphere, the corrosion resistance of the bare 55% Al-Zn/steel sheets was higher than of the galvanized steel, and the polyurethane painting system was more protective than the alkyd and epoxy ones, which degraded after 6-7 years of exposure.

  5. Investigations of phosphate coatings of galvanized steel sheets by a surface-analytical multi-method approach

    International Nuclear Information System (INIS)

    Bubert, H.; Garten, R.; Klockenkaemper, R.; Puderbach, H.

    1983-01-01

    Corrosion protective coatings on galvanized steel sheets have been studied by a combination of SEM, EDX, AES, ISS and SIMS. Analytical statements concerning such rough, poly-crystalline and contaminated surfaces of technical samples are quite difficult to obtain. The use of a surface-analytical multi-method approach overcomes, the intrinsic limitations of the individual method applied, thus resulting in a consistent picture of those technical surfaces. Such results can be used to examine technical faults and to optimize the technical process. (Author)

  6. Issues in recycling galvanized scrap

    Energy Technology Data Exchange (ETDEWEB)

    Koros, P.J. [LTV Steel Co., Inc., Cleveland, OH (United States); Hellickson, D.A. [General Motors Corp., Detroit, MI (United States); Dudek, F.J. [Argonne National Lab., IL (United States)

    1995-02-10

    The quality of the steel used for most galvanizing (and tinplate) applications makes scrap derived from their production and use a premier solid charge material for steelmaking. In 1989 the AISI created a Task Force to define the issues and to recommend technologically and economically sound approaches to assure continued, unhindered recyclability of the growing volume of galvanized scrap. The AISI program addressed the treatment of full-sized industrial bales of scrap. The current, on-going MRI (US)--Argonne National Laboratory program is focused on ``loose`` scrap from industrial and post-consumer sources. Results from these programs, issues of scrap management from source to steel melting, the choices for handling zinc in iron and steelmaking and the benefits/costs for removal of zinc (and lead) from scrap prior to melting in BOF and foundry operations are reviewed in this paper.

  7. Investigation of the cut-edge corrosion of organically-coated galvanized steel after accelerated atmospheric corrosion test

    Directory of Open Access Journals (Sweden)

    Reşit Yıldız

    2015-11-01

    Full Text Available The cut edge corrosion of organically coated (epoxy, polyurethane and polyester galvanized steel was investigated using electrochemical impedance spectroscopy (EIS. Measurements were performed on specimens that had been tested in an accelerated atmospheric corrosion test. The samples were subjected to 10 s fogging and 1 h awaiting cycles in an exposure cabinet (120 and 180 days with artificial acid rain solution. According to the investigation, the coatings were damaged from the cut edge into the sheet, this distance was about 0.8 cm. These defects were more pronounced at after 180 days in proportion to after 120 days.

  8. Experiments on different materials (polyamide, stainless & galvanized steel) influencing geothermal CaCO3 scaling formation: Polymorphs & elemental incorporation

    Science.gov (United States)

    Wedenig, Michael; Dietzel, Martin; Boch, Ronny; Hippler, Dorothee

    2016-04-01

    Thermal water is increasingly used for heat and electric power production providing base-load capable renewable and virtually unlimited geothermal energy. Compared to other energy sources geothermal facilities are less harmful to the environment, i.e. chemically and visually. In order to promote the economic viability of these systems compared to other traditional and renewable energy sources, production hindering processes such as corrosion and scaling of components arising from the typically high salinity thermal waters have to be considered as important economic factors. In this context, using proper materials being in contact with the thermal water is crucial and a playground for further improvements. Aim of the study presented, are basic experiments and observations of scaling and corrosive effects from hydrothermal water interacting with different materials and surfaces (stainless steel, polyamide, galvanized steel) and in particular the nucleation and growth effects of these materials regarding the precipitation of solid carbonate phases. The incorporation of Mg, Sr and Ba cations into the carbonate scalings are investigated as environmental proxy. For this purpose, hydrothermal carbonate precipitating experiments were initialized by mixing NaHCO3 and Ca-Mg-Sr-Ba-chloride solutions at temperatures ranging from 40 to 80 °C in glass reactors hosting artificial substrates of the above mentioned materials. The experiments show a strong dependence of the precipitation behaviour of calcium carbonate polymorphs on the particular material being present. Stainless steel and polyamide seem to restrict aragonite formation, whereas galvanized steel supports aragonite nucleation. Vaterite formation is promoted by polyamide surfaces. Importantly, vaterite is more soluble (less stable) compared to the other anhydrous calcium carbonate polymorphs, i.e. vaterite can be more easily re-dissolved. Thus, the use of polyamide components might reduce the amount and durability of

  9. Influence of laser beam incidence angle on laser lap welding quality of galvanized steels

    Science.gov (United States)

    Mei, Lifang; Yan, Dongbing; Chen, Genyu; Wang, Zhenhui; Chen, Shuixuan

    2017-11-01

    Based on the characteristics of laser welded structural parts of auto bodies, the influence of variation in laser beam incidence angle on the lap welding performance of galvanized auto-body sheets was studied. Lap welding tests were carried out on the galvanized sheets for auto-body application at different laser beam incidence angles by using the optimal welding parameters obtained through orthogonal experiment. The effects of incidence angle variation on seam appearance, cross-sectional shape, joint mechanical properties and microstructure of weldments were analyzed. In addition, the main factors influencing the value of incidence angle were investigated. According to the results, the weld seams had a good appearance as well as a fine, and uniform microstructure when the laser beam incidence angle was smaller than the critical incidence angle, and thus they could withstand great tensile and shear loads. Moreover, all tensile-shear specimens were fractured in the base material zone. When the laser beam incidence angle was larger than the critical incidence angle, defects like shrinkage and collapse tended to emerge, thereby resulting in the deteriorated weldability of specimens. Meanwhile, factors like the type and thickness of sheet, weld width as well as inter-sheet gap all had a certain effect on the value of laser beam incidence angle. When the sheet thickness was small and the weld width was narrow, the laser beam incidence angle could be increased appropriately. At the same time, small changes in the inter-sheet gap could greatly impact the value of incidence angle. When the inter-sheet gap was small, the laser beam incidence angle should not be too large.

  10. Corrosion inhibition in drinking water: Effect of temperature. Part I. Galvanized steel. Inhibicion de la corrosion en agua potable. Efecto de la temperatura. I parte. Acero galvanizado

    Energy Technology Data Exchange (ETDEWEB)

    Royuela, J.J.

    1994-01-01

    The corrosivity of several drinking waters, with and without addition of sodium silicate and sodium polyphosphate as inhibitor, in contact with galvanized steel, is studied in the range 20-65 degree centigree. The corrosion rate in the course of time was followed by means of the polarization resistance method. Linearity between potential and intensity of current is observed in the range-20 to + 30 mV from corrosion potential E[sub 0]. Polarization curves were also drawn with the aim to obtain the Tafel slopes. E[sub 0] values are more active when inhibitor is present. With temperature increases corrosion rate. Inhibitor addition to the waters tested means a reduction of galvanized steel corrosion of about 40%. (Author) 30 refs.

  11. Evolution of deformation heterogeneity at multiple length scales in a strongly textured zinc layer on galvanized steel

    International Nuclear Information System (INIS)

    Ghosh, A; Gurao, N P

    2015-01-01

    The evolution of heterogeneity of plastic deformation in a zinc layer has been probed at multiple length scales using a battery of characterization tools like X-ray diffraction, electron back scatter diffraction (EBSD) and digital image correlation. The experimental results indicate that plastic deformation is heterogeneous at different length scales and the value of micro, meso and macro strain by different characterization techniques shows a different value. The value of strain determined at the meso and micro length scale from EBSD and X-ray diffraction was negligible, however, the macro-strain as determined from X-ray peak shift was significant. EBSD results showed evidence of profuse {101-bar2} <101-bar1> contraction twinning in the zinc layer with higher intragranular misorientation in the twin compared to the matrix. It is therefore, inferred that the evolution of higher intergranular (between matrix and twin) strain due to prolific contraction twinning contributes to the failure of zinc layer on galvanized steel. (paper)

  12. Imposed potential measurement to evaluate the pitting corrosion resistance and the galvanic behaviour of a highly alloyed austenitic stainless steel and its weldment in a LiBr solution at temperatures up to 150ºC

    OpenAIRE

    Blasco Tamarit, María Encarnación; García García, Dionisio Miguel; García Antón, José

    2011-01-01

    Pitting corrosion resistance and galvanic behaviour of Alloy 31, a highly alloyed austenitic stainless steel (UNS N08031), and its weldment were studied in a heavy brine LiBr solution 1080 g/l at different temperatures (75–150 °C) using electrochemical techniques. The Mixed Potential Theory was used to evaluate the galvanic corrosion between the base and welded metals. Cyclic potentiodynamic curves indicate that high temperatures make passivation and repassivation of pits difficult, because t...

  13. Effects of Solution Annealing Temperature on the Galvanic Corrosion Behavior of the Super Duplex Stainless Steels

    Science.gov (United States)

    Lee, Jun-Seob; Jeon, Soon-Hyeok; Park, Yong-Soo

    2013-02-01

    This study investigated the active dissolution of super duplex stainless steel (SDSS) at various solution annealing temperatures. The active dissolutions of the α-phase and γ-phase were compared, and the effects of the surface area ratio on the active dissolutions of both phases were investigated. There were two peaks in the active-passive transition region in the potentiodynamic test in the modified green-death solution. The two peaks changed as the solution annealing temperature was increased from 1050 to 1150 °C. The solution annealing temperature difference affected the critical anodic current densities. This provides useful information for determining the appropriate solution annealing temperature in the modified green-death solution for SDSS.

  14. 76 FR 55031 - Galvanized Steel Wire From the People's Republic of China: Preliminary Affirmative Countervailing...

    Science.gov (United States)

    2011-09-06

    ... Less Than Fair Value: Static Random Access Memory Semiconductors From Taiwan, 63 FR 8909, 8932...) officials or representatives during the POI. A discussion of whether and how operational or strategic... government or CCP officials during the POI. A discussion of whether and how operational or strategic...

  15. The Characteristics of Cr-Free Coating Hot Dip Galvanized Sheet Steel

    International Nuclear Information System (INIS)

    Kim, Jong Gi; Moon, Man Been; Yun, Jeong Mo

    2011-01-01

    The greatest purpose of chromate treatment is to improve anti-corrosion by stabilizing a metal surface. Because metal surface forms a compound by absorbing oxygen or water in the air by being generally unstable, it is necessary to improve anti-corrosion of the metal by forming the metal surface with a stable film. When considering the economical efficiency and requirements together because the film of the metal surface treated with chromate has good anti-corrosion and the stability also in the air by being compact and strong, Chromate treatment has been used most up to the electronics industry from the auto industry. However, these days, because hexavalent chromium is both a toxic agent to be able to cause cancers and deadly poisonous environmental pollutant, the strong legal controls on its use is being imposed all over the world. Because of this reason, a new anti-corrosion method is being required. Also, by users' various demands, the passivations that have recently been developed require various characteristics such as conductivity, chemical resistance, alkali cleaning resistance as well as anti-corrosion. We could confirm the results such as excellent anti-corrosion compared to chromate, conductivity, chemical resistance and detergent resistance as the result of analysis of various characteristics of the galvannealed sheet steels coated with Cr-Free solution developed in this research

  16. Chemical processes of galvanized steel corrosion in the post-LOCA phase of a PWR and the prevention of sump screen clogging

    International Nuclear Information System (INIS)

    Hoffmann, W.; Kryk, H.

    2012-09-01

    The Emergency Core Coolant System has to remove the decay heat in case of a Loss of Coolant Accident (LOCA). Therefore, the emergency core cooling pumps recirculate the fluid from the sump back into the primary circuit. Sump strainers are mounted at the pump inlets to retain particles and fibrous insulation material. A fiber bed formed on strainers may act as an additional debris filter. However, a critical increase of pressure drop generated by debris or corrosion products could cause a failure of emergency cooling. Problems of insulation materials NUKON R (fiberglass) or CalSil and Aluminium may appear if containment spray systems using alkaline additives are installed. In such cases, dissolution / precipitation reactions resulting from insulation materials were observed, which increase the risk of sump screen blockage. In German NPPs, there are no containments spray systems, and insulation consists of more resistant materials like mineral wool (rock wool) and stainless steel. However, large scale experiments from AREVA have shown that sump screen clogging may be initiated by boric acid containing For generic investigations of galvanized steel corrosion behaviour under post-LOCA conditions, the down-scaled test facility KorrVA was designed consisting of a loop with trickle section (location of LOCA), bath section (sump), horizontal strainer and circulation pump. The low coolant volume (60 L) permits an easy and efficient purification between the experiments including complete removal of corrosion products. About 90 experiments were carried out with galvanized steel gratings and galvanized steel coupons in boric acid media in order to determine corrosion mechanisms depending on different experimental conditions like temperature, water chemistry and hydrodynamic conditions (flow impact, simulated by different nozzles). Practically, the fiber bed was prepared during a preliminary stage with the aim to separate effects of fiber bed formation on sump strainer clogging

  17. An experimental study on fracture toughness of resistance spot welded galvanized and ungalvanized DP 450 steel sheets used in automotive body

    Directory of Open Access Journals (Sweden)

    Sevim, Ibrahim

    2016-09-01

    Full Text Available The purpose of this study is to determine fracture toughness of Resistance Spot Welded (RSW Dual Phase (DP steels. RSW of galvanized and ungalvanized DP 450 steel sheets was carried out on spot welding machine. Fracture toughness of RSW joints of galvanized and ungalvanized DP 450 steel sheets was calculated from tensile-shear tests. New empirical equations were developed using Least Squares Method (LSM between energy release rate, fracture toughness and critical crack size depending on the relationship between hardness and fracture toughness values. Results indicated that fracture toughness of joints welded by using RSW increased exponentially while the hardness decreased. In addition, fracture toughness and energy release rate of RSW galvanized DP 450 steel sheets were lower compared to RSW ungalvanized DP 450 steel sheets which had approximately the same hardness.El objetivo de este estudio es determinar la tenacidad de fractura de los aceros dual (DP soldados por puntos de resistencia (RSW. En la máquina de soldadura por puntos se realizó la soldadura de láminas de acero DP 450 galvanizado y sin galvanizar. A partir de los ensayos de tracción-cizallamiento, se calculó la tenacidad a la fractura de las uniones del acero DP 450 galvanizado y sin galvanizar. Aplicando el método de mínimos cuadrados (LSM se desarrollaron nuevas ecuaciones empíricas entre el porcentaje de energía liberada, la tenacidad de fractura y el tamaño de grieta crítica en función de la relación entre los valores de tenacidad de fractura y de dureza. Los resultados indicaron que la tenacidad de fractura de las uniones soldadas por RSW aumentó exponencialmente, mientras que la dureza disminuyó. Además, el porcentaje de energía liberada de las láminas de acero DP 450 galvanizadas y soldadas fueron menores que en el caso de las láminas sin galvanizar a valores iguales de dureza.

  18. 76 FR 68422 - Galvanized Steel Wire From Mexico: Preliminary Determination of Sales at Less Than Fair Value and...

    Science.gov (United States)

    2011-11-04

    ... Mexico: Preliminary Determination of Sales at Less Than Fair Value and Postponement of Final... United States at less than fair value (LTFV), as provided in section 733(b) of the Tariff Act of 1930, as.... Fair Value Comparisons To determine whether respondents' sales of galvanized wire from Mexico to the...

  19. Imposed currents in galvanic cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Soestbergen, M.; Bazant, M.Z.

    2009-01-01

    We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation in the galvanic discharging mode, spontaneously generating a positive current

  20. The effect of immersion time to low carbon steel hardness and microstructure with hot dip galvanizing coating method

    Science.gov (United States)

    Hakim, A. A.; Rajagukguk, T. O.; Sumardi, S.

    2018-01-01

    Along with developing necessities of metal materials, these rise demands of quality improvements and material protections especially the mechanical properties of the material. This research used hot dip galvanizing coating method. The objectives of this research were to find out Rockwell hardness (HRb), layer thickness, micro structure and observation with Scanning Electron Microscope (SEM) from result of coating by using Hot Dip Galvanizing coating method with immersion time of 3, 6, 9, and 12 minutes at 460°C. The result shows that Highest Rockwell hardness test (HRb) was at 3 minutes immersion time with 76.012 HRb. Highest thickness result was 217.3 μm at 12 minutes immersion. Microstructure test result showed that coating was formed at eta, zeta, delta and gamma phases, while Scanning Electron Microscope (SEM) showed Fe, Zn, Mn, Si and S elements at the specimens after coating.

  1. Aerosol characterization and pulmonary responses in rats after short-term inhalation of fumes generated during resistance spot welding of galvanized steel

    Directory of Open Access Journals (Sweden)

    James M. Antonini

    Full Text Available Resistance spot welding is a common process to join metals in the automotive industry. Adhesives are often used as sealers to seams of metals that are joined. Anti-spatter compounds sometimes are sprayed onto metals to be welded to improve the weldability. Spot welding produces complex aerosols composed of metal and volatile compounds (VOCs which can cause lung disease in workers. Male Sprague-Dawley rats (n = 12/treatment group were exposed by inhalation to 25 mg/m3 of aerosol for 4 h/day × 8 days during spot welding of galvanized zinc (Zn-coated steel in the presence or absence of a glue or anti-spatter spray. Controls were exposed to filtered air. Particle size distribution and chemical composition of the generated aerosol were determined. At 1 and 7 days after exposure, bronchoalveolar lavage (BAL was performed to assess lung toxicity. The generated particles mostly were in the submicron size range with a significant number of nanometer-sized particles formed. The primary metals present in the fumes were Fe (72.5% and Zn (26.3%. The addition of the anti-spatter spray and glue did affect particle size distribution when spot welding galvanized steel, whereas they had no effect on metal composition. Multiple VOCs (e.g., methyl methacrylate, acetaldehyde, ethanol, acetone, benzene, xylene were identified when spot welding using either the glue or the anti-spatter spray that were not present when welding alone. Markers of lung injury (BAL lactate dehydrogenase and inflammation (total BAL cells/neutrophils and cytokines/chemokines were significantly elevated compared to controls 1 day after exposure to the spot welding fumes. The elevated pulmonary response was transient as lung toxicity mostly returned to control values by 7 days. The VOCs or the concentrations that they were generated during the animal exposures had no measurable effect on the pulmonary responses. Inhalation of galvanized spot welding fumes caused acute lung toxicity

  2. Problems with reliability and safety of hot dip galvanized steel structures Problemas com a confiabilidade e segurança de estruturas de aço galvanizadas a quente

    Directory of Open Access Journals (Sweden)

    L. Mraz

    2009-06-01

    Full Text Available Hot dip galvanizing is very effective means of protection against corrosion. Some recommendation concerning the steel quality are generally known and accepted. The process consists of cleaning (pickling or sand blasting and dipping the structures or pieces into liquid zinc bath. The case study of hot dip galvanized steels is presented. Some recent failures of hot dip galvanized welded structures and hot dip galvanized high strength steel screws are presented. Structures were made of S355 grade steel and MIG/MAG process was applied for welding. Large cracks were observed in the vicinity of welds after hot dip galvanizing process. The presence of both hydrogen and liquid metal embrittlement was identified and associated mainly with higher hardness of HAZ or the quenched and tempered steels. Possible cracking mechanisms are discussed. The influence of chemical composition and production process (welding, heat treatment was analyzed according to data published in literature. The solutions and recommendations for avoiding the failure in hot dip galvanized structures are proposed.Galvanização a quente é um meio muito efetivo de proteção contra a corrosão. Recomendações relativas a qualidade do aço são geralmente conhecidas e aceitas. O processo consiste de limpar (decapagem ou jateamento e mergulhar as estruturas ou partes destas em um banho de zinco líquido. O presente trabalho apresenta casos de falhas recentes em estruturas soldadas e em parafusos de aços de alta resistência galvanizados a quente. As estruturas foram fabricadas com aço do grau S355 e o processo MIG/MAG foi usado para a soldagem. Os parafusos foram fabricados com aço de alto carbono. Grandes trincas foram observadas nas proximidades das soldas após o processo de galvanização a quente. A ocorrência de fragilização tanto por hidrogênio como por metal líquido foi identificada e associada com a dureza elevada tanto da ZTA como dos aços temperados e revenidos. Os

  3. Application of artificial neural network and adaptive neuro-fuzzy inference system to investigate corrosion rate of zirconium-based nano-ceramic layer on galvanized steel in 3.5% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Mousavifard, S.M. [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Attar, M.M., E-mail: attar@aut.ac.ir [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ghanbari, A. [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Dadgar, M. [Textile Engineering Department, Neyshabur University, Neyshabur (Iran, Islamic Republic of)

    2015-08-05

    Highlights: • Film formation of Zr-based conversion coating under different conditions was investigated. • We study the effect of some parameters on anticorrosion performance of conversion coating. • Optimization of processing conditions for surface treatment of galvanized steel was obtained. • Modeling and predicting corrosion current density of treated surfaces was performed using ANN and ANFIS. - Abstract: A nano-ceramic Zr-based conversion solution was prepared and optimization of Zr concentration, pH, temperature and immersion time for the treatment of hot-dip galvanized steel (HDG) was performed. SEM microscopy was utilized to investigate the microstructure and film formation of the layer and the anticorrosion performance of conversion coating was studied using polarization test. Artificial intelligence systems (ANN and ANFIS) were applied on the data obtained from polarization test and the models for predicting corrosion current density values were attained. The outcome of these models showed proper predictability of the methods. The influence of input parameters was discussed and the optimized conditions for Zr-based conversion layer formation on the galvanized steel were obtained as follows: pH 3.8–4.5, Zr concentration of about 100 ppm, ambient temperature and immersion time of about 90 s.

  4. Grey–Taguchi method to optimize the percent zinc coating balances edge joints for galvanized steel sheets using metal inert gas pulse brazing process

    Directory of Open Access Journals (Sweden)

    Khasempong Songsorn

    2016-06-01

    Full Text Available The objective of this work was to optimize the percent zinc coating balances edge joints of galvanized steel sheets using the metal inert gas pulse brazing process. The Taguchi method and grey relational analysis were used to determine the relationship between the metal inert gas pulse brazing process parameters and percent zinc coating balances edge joints. The metal inert gas pulse brazing process parameters used in this study included wire feed speeds, arc voltages, travel speed, peak currents, and pulse frequency. The characteristics of metal inert gas pulse brazing process that were considered to find response were percent zinc coating balances edge joints on the upper edge joint (PZBEJ1, the lower edge joint (PZBEJ2, and the back sides of the edge joint (PZBEJ3. Analysis of variance was performed to determine the impact of an individual process parameter on the quality parameters. The results showed that the optimal parameters in which grey relational grade increases at the highest level were wire feed speeds at 3.25 m/min, arc voltages at 16 V, travel speeds at 0.9 m/min, peak currents at 425 A, and pulse frequency at 35 Hz. These parameters gave a 74.90% higher response value than those of the initial parameters of metal inert gas pulse brazing process.

  5. Efeito do tipo de revestimento na soldagem a ponto de aços galvanizados Effect of coating type on spot welding of galvanized steel

    Directory of Open Access Journals (Sweden)

    Tarcélio Anício da Silva

    2010-09-01

    -Cu (brass. Spot welding tests were carried out in IF steels coated in an industrial hot-dip galvanizing line with pure zinc (GI and a Zn-Fe alloy (GA. Three welding joints were evaluated: GA/GA, GI/GI and GA/GI. Dynamic weldability diagrams and electrode life were determined for each kind of joint. The results indicated that welding current increased more quickly with the number of welds for the GI/ GI joints. This result was associated with the fastest contamination of the electrode by zinc. For the GA/GI joints, welding current levels for adequate welding increased faster than for GA/GA joints but slower than for GI/GI joints. In general, the spot welding tests with GA/GI joints presented results closer to that of the GA/GA joints than to the spot welding tests with GI/GI joints. Such results showed the positive influence of the GA coating, even for joints including both coatings to improve the spot weldability of zinc coated steels.

  6. Part I. Corrosion studies of continuous alumina fiber reinforced aluminum-matrix composites. Part II. Galvanic corrosion between continuous alumina fiber reinforced aluminum-matrix composites and 4340 steel

    Science.gov (United States)

    Zhu, Jun

    Part I. The corrosion performance of continuous alumina fiber reinforced aluminum-matrix composites (CF-AMCs) was investigated in both the laboratory and field environments by comparing them with their respective monolithic matrix alloys, i.e., pure Al, A1-2wt%Cu T6, and Al 6061 T6. The corrosion initiation sites were identified by monitoring the changes in the surface morphology. Corrosion current densities and pH profiles at localized corrosion sites were measured using the scanning-vibrating electrode technique and the scanning ion-selective electrode technique, respectively. The corrosion damage of the materials immersed in various electrolytes, as well as those exposed in a humidity chamber and outdoor environments, was evaluated. Potentiodynamic polarization behavior was also studied. The corrosion initiation for the composites in 3.15 wt% NaCl occurred primarily around the Fe-rich intermetallic particles, which preferentially existed around the fiber/matrix interface on the composites. The corrosion initiation sites were also caused by physical damage (e.g., localized deformation) to the composite surface. At localized corrosion sites, the buildup of acidity was enhanced by the formation of micro-crevices resulting from fibers left in relief as the matrix corroded. The composites that were tested in exposure experiments exhibited higher corrosion rates than their monolithic alloys. The composites and their monolithic alloys were subjected to pitting corrosion when anodically polarized in the 3.15 wt% NaCl, while they passivated when anodically polarized in 0.5 M Na2SO4. The experimental results indicated that the composites exhibited inferior corrosion resistance compared to their monolithic matrix alloys. Part II. Galvanic corrosion studies were conducted on CF-AMCs coupled to 4340 steel since CF-AMCs have low density and excellent mechanical properties and are being considered as potential jacketing materials for reinforcing steel gun barrels. Coupled and

  7. Overall model of the dynamic behaviour of the steel strip in an annealing heating furnace on a hot-dip galvanizing line

    Directory of Open Access Journals (Sweden)

    Fernández, R.

    2010-10-01

    Full Text Available Predicting the temperature of the steel strip in the annealing process in a hot-dip galvanizing line (HDGL is important to ensure the physical properties of the processed material. The development of an accurate model that is capable of predicting the temperature the strip will reach according to the furnace’s variations in temperature and speed, its dimensions and the steel’s chemical properties, is a requirement that is being increasingly called for by industrial plants of this nature. This paper presents a comparative study made between several types of algorithms of Data Mining and Artificial Intelligence for the design of an efficient and overall prediction model that will allow determining the strip’s variation in temperature according to the physico-chemical specifications of the coils to be processed, and fluctuations in temperature and speed that are recorded within the annealing process. The ultimate goal is to find a model that is effectively applicable to coils of new types of steel or sizes that are being processed for the first time. This model renders it possible to fine-tune the control model in order to standardise the treatment in areas of the strip in which there is a transition between coils of different sizes or types of steel.La predicción de la temperatura de la banda de acero dentro del proceso de recocido de una planta de galvanizado continuo en caliente es importante para garantizar las propiedades físicas del material procesado. El desarrollo de un modelo preciso que sea capaz de predecir la temperatura que va a alcanzar la banda según las variaciones de temperaturas y velocidades del horno, y sus dimensiones y propiedades químicas del acero, es una necesidad cada vez más demandada por este tipo de plantas industriales. En el presente estudio se muestra una comparativa realizada entre diversos tipos de algoritmos deMinería de Datos e Inteligencia Artificial para el desarrollo de un modelo de predicci

  8. Methods and solutions for galvanic waste water treatment

    Directory of Open Access Journals (Sweden)

    Makisha Nikolay

    2017-01-01

    Full Text Available Currently galvanic sludge is considered as one of the most dangerous wastes, which are formed during purification of galvanic wastewater. The slimes of galvanic production are the most toxic industrial waste and sources of heavy metals emitted into the environment. Galvanic sludge belongs to the third hazard class; these wastes need to be deposited in special landfills for toxic waste. These polygons are complex and require significant costs. In this regard, there is a need for such methods of purification of galvanic sewage sludge, which may be used in other industries or will have fourth class of hazard or below. This article compares the main methods of purification of galvanic waste waters in general and galvanic sludge in particular, currently introducing new techniques for treating industrial effluents. One of them considers treatment of galvanic waste water by means of suspensions of ferriferous hydrosol that is an electric generated coagulant derived from waste forming, steel wool, etc. There is a sort of experience already acquired in some countries how to use of ferropericlase.

  9. Contribution to the study of the influence of zinc bath composition on corrosion resistance of coatings obtained by galvanization

    International Nuclear Information System (INIS)

    Cabrillac, Claude

    1969-01-01

    This research thesis deals with the influence of zinc purity on the corrosion resistance of a coating obtained by galvanization, and on its effect on cathodic protection. This study therefore addresses methods and tests processes (notably salt spray test) aiming at assessing the efficiency of steel protection by hot galvanization, and aims at highlighting the influence of galvanization bath purity or composition on corrosion resistance of galvanized layers

  10. 49 CFR 192.619 - Maximum allowable operating pressure: Steel or plastic pipelines.

    Science.gov (United States)

    2010-10-01

    ... plastic pipelines. 192.619 Section 192.619 Transportation Other Regulations Relating to Transportation... Operations § 192.619 Maximum allowable operating pressure: Steel or plastic pipelines. (a) No person may operate a segment of steel or plastic pipeline at a pressure that exceeds a maximum allowable operating...

  11. Reduction in Energy Consumption & Variability in Steel Foundry Operations

    Energy Technology Data Exchange (ETDEWEB)

    Frank Peters

    2005-05-04

    This project worked to improve the efficiency of the steel casting industry by reducing the variability that occurs because of process and product variation. The project focused on the post shakeout operations since roughly half of the production costs are in this area. These improvements will reduce the amount of variability, making it easier to manage the operation and improve the competitiveness. The reduction in variability will also reduce the need for many rework operations, which will result in a direct reduction of energy usage, particularly by the reduction of repeated heat treatment operations. Further energy savings will be realized from the reduction of scrap and reduced handling. Field studies were conducted at ten steel foundries that represented the U.S. steel casting industry, for a total of over 100 weeks of production observation. These studies quantified the amount of variability, and looked toward determining the source. A focus of the data collected was the grinding operations since this is a major effort in the cleaning room, and it represents the overall casting quality. The grinding was divided into two categories, expected and unexpected. Expected grinding is that in which the location of the effort is known prior to making the casting, such as smoothing parting lines, gates, and riser contacts. Unexpected grinding, which was approximately 80% of the effort, was done to improve the surfaces at weld repair locations, to rectify burnt on sand, and other surface anomalies at random locations. Unexpected grinding represents about 80% of the grinding effort. By quantifying this effort, the project raised awareness within the industry and the industry is continuing to make improvements. The field studies showed that the amount of variation of grinding operations (normalized because of the diverse set of parts studied) was very consistent across the industry. The field studies identified several specific sources that individually contributed to

  12. A flat solar collector built from galvanized steel plate, working by thermosyphonic flow, optimized for Mexican conditions; Un colector solar plano construido de lamina de acero galvanizada, operando por flujo termosifonico, optimizado para las condiciones mexicanas

    Energy Technology Data Exchange (ETDEWEB)

    Marroquin de Jesus, A; Olivares Ramirez, J.M.; Ramos Lopez, G.A.; Pless, R.C. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro (Mexico)]. E-mail: amarroquind@utsjr.edu.mx

    2009-07-15

    Design, construction, and testing of the thermal performance of a flat solar collector for domestic water heating are described. The absorbing plate is built from readily available materials: two sheets of galvanized steel, one of the channelled types, the other one flat, which are joined by electric welding. The absorber is connected to a 198-L thermotank, insulated with polyurethane foam. In terms of receiving surface, the prototype tested here has an area of 1.35 m{sup 2}, about 20% smaller than comparable copper-tube-based collectors offered in the market. Temperature measurements conducted over a 30-day period gave values which were a few degrees lower than the theoretically calculated water temperatures. Momentary thermal efficiency values between 35% and 77% were observed. The water temperature achieved the tank at the end of the day averages 65 degrees Celsius in winter weather conditions in the central Mexican highland. This design of solar water heater is well suited to Mexican conditions, as it makes use of the high local intensity of the solar radiation, and as the channel shape of the ducts minimizes bursting during the rare occurrences of freezing temperatures in the region; it also has the advantage of being manufacturable at low cost from simple materials. [Spanish] Se describe el diseno, construccion y pruebas del desempeno termico de un colector solar plano para calentamiento de agua para uso domestico. La placa absorbedora se construyo de materiales facilmente asequibles: dos placas de acero galvanizado, una del tipo acanalado y la otra plana, unidas mediante soldadura de acero electrico. La placa absorbedora esta conectada a un termotanque con capacidad de 198 L, aislado con espuma de poliuretano. La superficie receptora de este prototipo es de 1.35 m{sup 2}, aproximadamente 20% mas pequena comparado con los colectores, basados en tubos de cobre, ofertados en el mercado. Mediciones de temperatura por un periodo de 30 dias, arrojaron valores

  13. Use of plain carbon steel and configuration management program for the metal industry

    International Nuclear Information System (INIS)

    Tariq, M.M.; Kalsoom, T.

    2006-01-01

    The application of Configuration Management (CM) and structural plain carbon steels for metal industry is studied. Requirements of surface treatment and heat treatment are also defined to achieve maximum for metal industry. Triangle of materials, properties and applications is discussed with in the role of CM. Equivalent plain carbon steel have been suggested, based on structural applications. Operating conditions for the required surface treatment e.g. paint, galvanizing or other coatings are studied. Role of CM is highlighted for these activities. (author)

  14. Microgalvanic corrosion of laser-welded HSLA steels

    NARCIS (Netherlands)

    Looi, Y.M.

    2008-01-01

    Laser welding of galvanized high strength low alloy (HSLA) steels leads to the evaporation of zinc at the weld and the formation of a heat-affected-zone (HAZ). High heat input due to welding generates macro galvanic coupling between the weld and the parent metal as well as micro galvanic corrosion

  15. Welding stainless steels for structures operating at liquid helium temperature

    Energy Technology Data Exchange (ETDEWEB)

    Witherell, C.E.

    1980-04-18

    Superconducting magnets for fusion energy reactors require massive monolithic stainless steel weldments which must operate at extremely low temperatures under stresses approaching 100 ksi (700 MPa). A three-year study was conducted to determine the feasibility of producing heavy-section welds having usable levels of strength and toughness at 4.2/sup 0/K for fabrication of these structures in Type 304LN plate. Seven welding processes were evaluated. Test weldments in full-thickness plate were made under severe restraint to simulate that of actual structures. Type 316L filler metal was used for most welds. Welds deposited under some conditions and which solidify as primary austenite have exhibited intergranular embrittlement at 4.2/sup 0/K. This is believed to be associated with grain boundary metal carbides or carbonitrides precipitated during reheating of already deposited beads by subsequent passes. Weld deposits which solidify as primary delta ferrite appear immune. Through use of fully austenitic filler metals of low nitrogen content under controlled shielded metal arc welding conditions, and through use of filler metals solidifying as primary delta ferrite where only minimum residuals remain to room temperature, welds of Type 316L composition have been made with 4.2K yield strength matching that of Type 304LN plate and acceptable levels of soundness, ductility and toughness.

  16. Measurements of residual deformations of steel-aluminum conductors in operating overhead lines

    Energy Technology Data Exchange (ETDEWEB)

    Durov, E.V.; Kesel' man, L.M.; Treiger, A.S.

    1982-12-01

    Experience in the operation of overhead power lines using steel-aluminum conductors is presented. Measurements were taken on the residual deformation of the steel-aluminum lines to determine the amount of sag increase and to forecast this increase for the entire period of operation. It is recommended that the work on measuring the residual deformation in the power lines be extended to a broader range of operating conditions such as conductors, spans, and climate conditions.

  17. 49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... anomalies during construction, strength testing and anticipated operational stresses. (4) The pipe must be...

  18. 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)

  19. STUDY OF OPERATION OF ARC STEEL FURNACE WITH CONOID BAY FLUSHING OF STEEL

    Directory of Open Access Journals (Sweden)

    M. A. Murikov

    2008-01-01

    Full Text Available The construction of the arc steel-furnace bay, the application of which allows to increase the speed of flush outflow, to provide reduction of the slag carry-over with metal, is offered.

  20. Characterization of solid wastes from two different hot-dip galvanizing processes

    International Nuclear Information System (INIS)

    Delvasto, P.; Casal-Ramos, J. a.; Gonzalez-Jordan, O.; Duran-Rodriguez, N. C.; Dominguez, J. R.; Moncada, P.

    2012-01-01

    Zinc dust and zinc ash from hot-dip galvanizing industries located in Venezuela were characterized using atomic spectroscopy, scanning electron microscopy, X-Ray diffraction and infrared spectroscopy. Dust was formed during the high-pressure drying process of the galvanized pieces, in a plant that uses a steel kettle to hold the molten zinc. Ash identified as A came from the same plant as the dust, while ash identified as B came from a hot-dip galvanizing plant which use a ceramic lined galvanizing furnace. Dust contained 98 wt % Zn, in metallic form. Both ash samples contained: Zn and ZnO, while Zn 5 (OH) 8 Cl 2 xH 2 O and ZnCl 2 were only found in ash B. Globally, ash ''A'' and ash ''B'' contain 71 and 75 wt % Zn, respectively. (Author)

  1. Production of some coagulant materials from galvanizing workshop waste

    Energy Technology Data Exchange (ETDEWEB)

    Cici, M.; Cuci, Y. [Firat Univ., Elazig (Turkey). Dept. of Environmental Engineering

    1998-09-01

    The aim of this study was to investigate production of some coagulant reagents which have been widely used in all water coagulation treatments using galvanizing waste of the Karadeniz Iron-Steel Plant in Turkey. The waste sample was analyzed by atomic absorption spectrophotometry and a gravimetric procedure. With different techniques, ferric chloro sulfate, FeClSO{sub 4}, ferric sulfate, Fe{sub 2}(SO{sub 4}){sub 3}, sodium ferrate, Na{sub 2}FeO{sub 4} and potassium ferrate, K{sub 2}FeO{sub 4} were obtained from galvanizing waste under laboratory conditions. Then the composition of each reagent was identified by qualitative and quantitative analyses, separately.

  2. Failure of austenitic stainless steel tubes during steam generator operation

    OpenAIRE

    M. Głowacka; J. Łabanowski; S. Topolska

    2012-01-01

    Purpose: of this study is to analyze the causes of premature failure of steam generator coil made of austenitic stainless steel. Special attention is paid to corrosion damage processes within the welded joints.Design/methodology/approach: Examinations were conducted several segments of the coil made of seamless cold-formed pipes Ø 23x2.3 mm, of austenitic stainless steel grade X6CrNiTi18-10 according to EN 10088-1:2007. The working time of the device was 6 months. The reason for the withdrawa...

  3. Effect of radiation damage on operating safety of steel pressure vessels of nuclear reactors

    International Nuclear Information System (INIS)

    Vacek, M.; Havel, S.; Stoces, B.; Brumovsky, M.

    1980-01-01

    The effects are assessed of the environment upon mechanical properties of steel used generally for pressure vessels of light water nuclear reactors. Changes caused by radiation affect the reliability of vessels. Deterioration of steel properties is mainly due to neutron radiation. The article deals with factors bearing upon damage and with methods allowing to evaluate the reliability of vessels and predict their service life. Operating reliability of vessels is very unfavourably affected by planned and accidental reactor transients. (author)

  4. 46 CFR 54.25-10 - Low temperature operation-ferritic steels (replaces UCS-65 through UCS-67).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Low temperature operation-ferritic steels (replaces UCS... (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-10 Low temperature operation—ferritic steels (replaces UCS-65 through UCS-67). (a) Scope. (1) This...

  5. 46 CFR 54.25-15 - Low temperature operation-high alloy steels (modifies UHA-23(b) and UHA-51).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Low temperature operation-high alloy steels (modifies... (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-15 Low temperature operation—high alloy steels (modifies UHA-23(b) and UHA-51). (a) Toughness...

  6. 46 CFR 54.25-20 - Low temperature operation-ferritic steels with properties enhanced by heat treatment (modifies...

    Science.gov (United States)

    2010-10-01

    ... VESSELS Construction With Carbon, Alloy, and Heat Treated Steels § 54.25-20 Low temperature operation—ferritic steels with properties enhanced by heat treatment (modifies UHT-5(c), UHT-6, UHT-23, and UHT-82... 46 Shipping 2 2010-10-01 2010-10-01 false Low temperature operation-ferritic steels with...

  7. Experimental Study on Rebar Corrosion Using the Galvanic Sensor Combined with the Electronic Resistance Technique

    Science.gov (United States)

    Xu, Yunze; Li, Kaiqiang; Liu, Liang; Yang, Lujia; Wang, Xiaona; Huang, Yi

    2016-01-01

    In this paper, a new kind of carbon steel (CS) and stainless steel (SS) galvanic sensor system was developed for the study of rebar corrosion in different pore solution conditions. Through the special design of the CS and SS electronic coupons, the electronic resistance (ER) method and zero resistance ammeter (ZRA) technique were used simultaneously for the measurement of both the galvanic current and the corrosion depth. The corrosion processes in different solution conditions were also studied by linear polarization resistance (LPR) and the measurements of polarization curves. The test result shows that the galvanic current noise can provide detailed information of the corrosion processes. When localized corrosion occurs, the corrosion rate measured by the ER method is lower than the real corrosion rate. However, the value measured by the LPR method is higher than the real corrosion rate. The galvanic current and the corrosion current measured by the LPR method shows linear correlation in chloride-containing saturated Ca(OH)2 solution. The relationship between the corrosion current differences measured by the CS electronic coupons and the galvanic current between the CS and SS electronic coupons can also be used to evaluate the localized corrosion in reinforced concrete. PMID:27618054

  8. A Noble Approach of Process Automation in Galvanized Nut, Bolt Manufacturing Industry

    Directory of Open Access Journals (Sweden)

    Akash Samanta

    2012-05-01

    Full Text Available Corrosion costs money”, The Columbus battle institute estimates that corrosion costs Americans more than $ 220 billion annually, about 4.3% of the gross natural product [1].Now a days due to increase of pollution, the rate of corrosion is also increasing day-by-day mainly in India, so, to save the steel structures, galvanizing is the best and the simplest solution. Due to this reason galvanizing industries are increasing day-by-day since mid of 1700s.Galvanizing is a controlled metallurgical combination of zinc and steel that can provide a corrosion resistance in a wide variety of environment. In fact, the galvanized metal corrosion resistance factor can be some 70 to 80 times greater that the base metal material. Keeping in mind the importance of this industry, a noble approach of process automation in galvanized nut-bolt  manufacturing plant is presented here as nuts and bolts are the prime ingredient of any structure. In this paper the main objectives of any industry like survival, profit maximization, profit satisfying and sales growth are fulfilled. Furthermore the environmental aspects i.e. pollution control and energy saving are also considered in this paper. The whole automation process is done using programmable logic controller (PLC which has number of unique advantages like being faster, reliable, requires less maintenance and reprogrammable. The whole system has been designed and tested using GE, FANUC PLC.

  9. Deformation and fatigue behavior of hot dip galvanized coatings

    International Nuclear Information System (INIS)

    Camurri, Carlos P.; Benavente, Raul G.; Roa, Isidoro S.; Carrasco, Claudia C.

    2005-01-01

    This paper reports on the results of a study of the effect of static and dynamic stresses on hot dip galvanized coatings on SAE 1020 steel substrates. Galvanizing was performed using baths maintained at 450 deg. C, the zinc containing 0.16% Ti and 0.02% Fe and with Al and Ni in the ranges 0-0.20% and 0-0.30%, respectively. Static three-point bend tests were conducted with applied stresses in the range 428-790 MPa. Dynamic bend-fatigue tests involved stresses in the range 228-578 MPa at a cyclic frequency of 0.25 Hz for up to 700 cycles. The total crack density in the coatings was measured before and after the tests using light optical and electron microscopy. The results showed that the crack density increased as the applied stress increased and crack propagation was promoted perpendicular to the substrate. The number of cycles had no effect on the crack density and propagation at stresses lower than 386 MPa. At higher stresses the number of applied cycles contributed only to crack propagation. It was concluded that the best bath composition for preventing fatigue crack propagation is one that minimized the formation of thinner brittle layers in the galvanized coatings

  10. Welded repair joints of boiler steels following operation in creep conditions exceeding the design time of operation

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, J.; Paszkowska, H.; Zielinski, A. [Institute for Ferrous Metallurgy, Gliwice (Poland)

    2010-07-01

    The assessment of suitability for further operation for materials and welded repair joints of thick-walled main steam pipeline components, made of steel 14MoV63, as well as steam superheater outlet headers made of steel X20CrMoV121 following operation in creep conditions in time periods considerably longer than the specified calculated time of operation. Strength properties, impact strength and transition temperature into brittle condition, as well as structure condition have been evaluated. On the basis of shortened creep tests, the residual life and disposable residual life of materials and welded joints have been determined. Material properties following operation and those of fabricated circumferential welded repair joints have been compared. The condition of examined components and suitability of the fabricated welded repair joints for further operation have been assessed. (orig.)

  11. Experimental study and calculation of boiling heat transfer on steel plates during runout table operation

    International Nuclear Information System (INIS)

    Liu, Z.D.; Fraser, D.; Samarasekera, I.V.

    2002-01-01

    Within a hot strip steel mill, red hot steel is hot rolled into a long continuous slab that is led onto what is called the runout table. Temperatures of the steel at the beginning of this table are around 900 o C. Above and below the runout table are banks of water jets, sprays or water curtains that rapidly cool the steel slab. The heat transfer process itself may be considered one of the most complicated in the industrial world. The cooling process that occurs on the runout table is crucial and governs the final mechanical properties and flatness of a steel strip. However, very limited data of industrial conditions has been available and that which is available is poorly understood. To study heat transfer during runout table cooling, an industrial scale pilot runout table facility was constructed at the University of British Columbia (UBC). This paper describes the experimental details, data acquisition and data handling techniques for steel plates during water jet impingement cooling by one circular water jet from industrial headers. The effect of cooling water temperature and initial steel plate temperature as well as varying water jet diameters on heat transfer was systematically investigated. A two-dimensional finite element scheme based inverse heat conduction model was developed to calculate surface heat transfer coefficients along the impinging surface. Heat flux curves at the stagnation area were obtained for selected tests. A quantitative relationship between adjustable processing parameters and heat transfer coefficients along the impinging surface during runout table operation is discussed. The results of the study were used to upgrade an extensive process model developed at UBC. The model ties in the cooling rate and hence two dimensional temperature gradients to the resulting microstructure and final mechanical properties of the steel. This process model is widely used by major steel industries in Canada and the United States. (author)

  12. ENVIRONMENTAL AND ECONOMIC ASPECTS OF ANTICORROSION PROTECTION BY HOT-DIP GALVANIZED METHOD REBARS IN CONCRETE

    Directory of Open Access Journals (Sweden)

    Hegyi Andreea

    2015-05-01

    Full Text Available The implementation of the sustainable development concept is nowadays a key issue in almost all human activities. For the constructions domain an European strategy has already been elaborated. Among its goals are also the use of long lasting materials and the reduction of repair costs. This paper presents an interdisciplinary study concerning the efficiency of the use of hot-dip galvanized rebar for concrete structures. Experimental results about corrosion kinetics of coated and usual steel reinforcement embedded in concrete, subjected to chlorine ions attack, are analyzed. Electrochemical methods as chronoamperometry and linear polarization have been used. Corrosion potential values recorded for galvanized steel embedded in concrete indicate an uncertain corrosion activation process up to a rate of 2.5 % calcium chloride relative to concrete. For rates of 5% CaCl2 and more the corrosion process is activated. For unprotected steel bars embedded in concrete the corrosion activation process started at all calcium chloride studied rates and higher corrosion potential values has been registered than for the hot-dip galvanized ones, at the same rates. Economical assessments have been done using entire lifetime cost analysis of the reinforced concrete structures. Despite that the hotdip galvanization is a rather expansive procedure, when taking into account the whole expected life span, the use of zinc coating proves to be efficient both from structural and financial approaches.

  13. Structural and mechanical degradation of 09Mn2Si pipe steel after long-term operation

    Science.gov (United States)

    Panin, S. V.; Marushchak, P. O.; Vlasov, I. V.; Eremin, A. V.; Byakov, A. V.; Syromyatnikova, A. S.; Stankevich, R.

    2017-12-01

    A comprehensive study of the structure and impact toughness of 09Mn2Si steel used in the construction of the main gas pipeline "Mastakh-Berge-Yakutsk" (taken from the linear part with the outer diameter of 530 mm and the wall thickness of 7 mm) after 37 years of operation was carried out. A comparative analysis of results obtained for the emergency stock steel was conducted. It was shown that long-term operation does not give rise to a substantial redistribution of cementite. Deformation aging is slightly expressed and is manifested through precipitation of finely dispersed carbides in the grain bulk. The revealed structure degradation almost does not make sense under hardness measurement. The most pronounced manifestation of structure changes is related to decreasing impact toughness of 09Mn2Si steel which reaches ˜2 times under negative temperatures.

  14. Application of nuclear methods in steel-making operations of TZ VRSR

    International Nuclear Information System (INIS)

    Kisiel, B.; Adamec, V.; Komarek, P.; Pietro, S.

    1987-01-01

    The use of radionuclides and nuclear methods at the Trinec iron works has a long tradition. In the early 1960's a radioisotope laboratory was established here for this purpose, which after ten years of work was transferred to the Research Institute of Iron Metallurgy at Dobra. The initial period was focused on the study of inclusions in steel of exogenous origin using the methods of radioactive and non-radioactive tracing. In recent years the operating applications of radionuclides were integrated in the research of the technology of steel production in an oxygen converter, this first within simulated experimental melts in open-hearth furnaces, later in the run-in operation of the oxygen converter steel works. The research was focused on the contamination of steel with coke dust, on alloying additions dissolution in the ladle, the dephosphorization process, the desulfurization process, etc. At present, nuclear methods are to be used for seeking the optimal technology of the production of steel of peak quality, prospectively also of continuous casting. (author). 4 tabs

  15. 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

  16. Electrocatalysts Prepared by Galvanic Replacement

    Directory of Open Access Journals (Sweden)

    Athanasios Papaderakis

    2017-03-01

    Full Text Available Galvanic replacement is the spontaneous replacement of surface layers of a metal, M, by a more noble metal, Mnoble, when the former is treated with a solution containing the latter in ionic form, according to the general replacement reaction: nM + mMnoblen+ → nMm+ + mMnoble. The reaction is driven by the difference in the equilibrium potential of the two metal/metal ion redox couples and, to avoid parasitic cathodic processes such as oxygen reduction and (in some cases hydrogen evolution too, both oxygen levels and the pH must be optimized. The resulting bimetallic material can in principle have a Mnoble-rich shell and M-rich core (denoted as Mnoble(M leading to a possible decrease in noble metal loading and the modification of its properties by the underlying metal M. This paper reviews a number of bimetallic or ternary electrocatalytic materials prepared by galvanic replacement for fuel cell, electrolysis and electrosynthesis reactions. These include oxygen reduction, methanol, formic acid and ethanol oxidation, hydrogen evolution and oxidation, oxygen evolution, borohydride oxidation, and halide reduction. Methods for depositing the precursor metal M on the support material (electrodeposition, electroless deposition, photodeposition as well as the various options for the support are also reviewed.

  17. Application of Boundary Element Method in Galvanic Corrosion Analysis for Metallic Materials used in Nuclear Power Plant

    International Nuclear Information System (INIS)

    Zaifol Samsu; Muhamad Daud; Siti Radiah Mohd Kamarudin

    2011-01-01

    Boundary element method (BEM) is a numerical technique that used for modeling infinite domain as is the case for galvanic corrosion analysis. This paper presents the application of boundary element method for galvanic corrosion analysis between two different metallic materials. Aluminium (Al), and zinc (Zn) alloys were used separately coupled with the Carbon Steel (CS) in natural seawater. The measured conductivity of sea water is 30,800 μS/ cm at ambient temperature. Computer software system based on boundary element likes BEASY and ABAQUS can be used to accurately model and simulate the galvanic corrosion. However, the BEM based BEASY program will be used reasonably for predicting the galvanic current density distribution of coupled Al-CS and Zn-CS in this study. (author)

  18. Galvanic reduction of uranium(III) chloride from LiCl-KCl eutectic salt using gadolinium metal

    Science.gov (United States)

    Bagri, Prashant; Zhang, Chao; Simpson, Michael F.

    2017-09-01

    The drawdown of actinides is an important unit operation to enable the recycling of electrorefiner salt and minimization of waste. A new method for the drawdown of actinide chlorides from LiCl-KCl molten salt has been demonstrated here. Using the galvanic interaction between the Gd/Gd(III) and U/U(III) redox reactions, it is shown that UCl3 concentration in eutectic LiCl-KCl can be reduced from 8.06 wt.% (1.39 mol %) to 0.72 wt.% (0.12 mol %) in about an hour via plating U metal onto a steel basket. This is a simple process for returning actinides to the electrorefiner and minimizing their loss to the salt waste stream.

  19. Operation corrosion test of austenitic steel bends for supercritical coal boilers

    Directory of Open Access Journals (Sweden)

    Cizner J.

    2016-03-01

    Full Text Available Corrosion tests of both annealed and not annealed bends of HR3C and S304H steels in operation conditions of black and brown coal combustion boilers in EPRU and EDE. After a long-term exposure, the samples were assessed gravimetrically and metallographically. The comparison of annealed and unannealed states showed higher corrosion rates in the annealed state; corrosion of the sample surface did not essentially differ for compression and tensile parts of the beams. Detailed assessment of both steels is described in detail in this study.

  20. A recycling process for dezincing steel scrap

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A.; Kellner, A.W.; Harrison, J. [Metal Recovery Industries, Inc., Hamilton, ON (Canada)

    1992-08-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  1. A recycling process for dezincing steel scrap

    Energy Technology Data Exchange (ETDEWEB)

    Dudek, F.J.; Daniels, E.J. (Argonne National Lab., IL (United States)); Morgan, W.A.; Kellner, A.W.; Harrison, J. (Metal Recovery Industries, Inc., Hamilton, ON (Canada))

    1992-01-01

    In response to the several-fold increase in consumption of galvanized steel in the last decade and the problems associated with refurnacing larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is electrowon as dendritic powder. The process is effective for zinc, lead, aluminum, and cadmium removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested for batch treatment of 1,000 tons of mostly baled scrap. A pilot plant to continuously treat loose scrap is under construction. Use of degalvanized steel scrap decreases raw materials and environmental compliance costs to steel- and iron-makers, may enable integrated steel producers to recycle furnace dusts to the sinter plant, and may enable EAF production of flat products without use of DRI or pig iron. Recycling the components of galvanized steel scrap saves primary energy, decreases zinc imports, and adds value to the scrap.

  2. Corrosion in PWR stainless steel components: a TSO perspective based on operating experience and expertises

    International Nuclear Information System (INIS)

    Curieres, I. de

    2015-01-01

    Stainless steels are used commonly in many circuits of a nuclear power plant. Particularly, they are the prime materials for the inside surface of the primary circuit. Their operating experience has been good, though a number of cases of degradations due to corrosion have been reported the last ten years. This number of events is increasing and many studies of damaged parts become available. Based on the operating experience and these studies, IRSN will provide its perspective on the safety-related issues associated with the corrosion of stainless steel components. It appears that today's knowledge is not sufficient to define relevant criteria or to determine the exact set of parameters which leads to SCC (Stress Corrosion Cracking) of stainless steels. As a consequence, the best strategy remains an inspection and repair/replacement one. Moreover many cases show the influence of pollutants in the SCC events. This emphasizes the fact that chemistry parameters are strongly connected to safety issues, with respect to the stainless steels integrity

  3. Bitbus data transport by galvanic interface

    International Nuclear Information System (INIS)

    Jansweijer, P.P.M; Hogenbirk, J.J.

    1988-01-01

    For a bitbus system in a raw environment galvanic interfaces are necessary. This report offers various possibilities for implementing such an galvanic interface. One of the possibilities is described in detail. Along the objects to be controlled an apart ringline runs in behalf of the bitbus. The various bitbus components which have been mounted near these objects, are coupled to this ringline via opto-couplers. (author). 6 refs.; 9 figs

  4. Effect of confinement on bond strength of hot-dip galvanized lap splices in concrete structures

    International Nuclear Information System (INIS)

    Fakhran, Mazen

    2004-01-01

    Galvanizing the reinforcing steel is one of the methods used to protect bars against corrosion. Galvanizing is a hot dip process where the reinforcing bars are immersed in an aqueous pre flux solution of zinc ammonium chloride at a controlled temperature between 840 and 850 degrees F. In 2001, a research program was started at AUB to evaluate experimentally the effect of hot dip galvanizing on the bond capacity of tension lap splices anchored in full-scale beam specimens designed to fail in bond splitting mode. The test results indicated that the use of galvanized bars had a negligible effect on bond strength of reinforcement in normal strength. However, galvanizing caused an average of 20 percent decrease in bond strength of reinforcement in high strength concrete. The primary objective of research reported in this thesis, is the need to find a solution to eliminate the bond reduction of galvanized bars in high strength concrete. It is significant to evaluate the positive effect of the addition of transverse reinforcement in the splice region. The hypothesis to be tested is that such transverse reinforcement will insure uniform bond stress distribution over the entire splice region, thus mobilizing all bar lugs along the splice in the stress transfer mechanism between the bar and the surrounding concrete. Such mechanism might reduce the significant decrease in bond strength in high strength concrete due to galvanizing. To achieve this objective, eighteen full-scale beam specimens were tested in positive bending. Each beam was reinforced with bars spliced in a constant moment region at midspam. The splice length was chosen in such a way that the beams failed in bond splitting of the concrete cover in the splice region. The main variables were type of coating (black or galvanized bars), bar size (20, 25 and 32 mm), and amount of transverse reinforcement in the splice region (0, 2 or 4 stirrups). The test results indicated that confinement did not have a significant

  5. Synthesis and electrochemical properties of composite galvanic Ni with carbon nanomaterials and PVD Mo coatings

    International Nuclear Information System (INIS)

    Drozdovich, V.B.; Chayeuski, V.V.; Zhdanok, S.A.; Barkovskaya, M.M.

    2011-01-01

    Double layer coatings Ni – Mo were obtained by electrolytic deposition of galvanic Ni and following arc PVD deposition of molybdenum. The ion plating coatings Mo on Ni foil and composition electrolytic Ni coatings with carbon nanomaterials (CNM) deposited on mild steel has been also investigated. Composite galvanic Ni coatings with CNM and ion plating coatings Mo contain separately obtained cubic α-Mo phase as well as fragmentary solid solution Mo in Ni. Such coatings exclude hydrogenation of Ni foundation in alkaline solution and possess enlarged electrocatalytic properties while emitting hydrogen and oxygen. Availability of carbon based nanomaterials in combined coatings is cause of an active absorption hydrogen after cathodic polarization. A formation on the surface layer of nanostructure solid solution (Ni, Mo) after compression plasma flows treatment with fixed parameters of patterns Mo/Ni/ mild steel take place. (authors)

  6. Study of machinability of VP 100 steel with different levels of titanium in end milling operations

    Directory of Open Access Journals (Sweden)

    Jean Robert Pereira Rodrigues

    2015-01-01

    Full Text Available During the manufacture of a mould, machining is certainly the most important process. The composition required to provide important properties in the steels used, such as hardness, wear and corrosion resistance, results in a low machinability has resulted in a low volume of material removed by the end of life of the cutting tool, due to the strong wear generate. In this study, we investigated the behavior of steel processing VP 100 is used in manufacturing plastic injection molds. To this end, we used two versions of VP100, one with 270 and another with 350 parts per million (ppm of titanium. The tests comprise six different cutting conditions in end milling operations. We observed the volume of material removed for each tested condition, considering the evolution of flank wear of tools to a maximum of0.5 mm. Steel VP 100 with 350 ppm of Ti showed a higher volume of material removed in five of six tests showing that, in this case, a higher content of titanium improved the machinability of the steel under study.

  7. Vibration and Operational Characteristics of a Composite-Steel (Hybrid) Gear

    Science.gov (United States)

    Handschuh, Robert F.; LaBerge, Kelsen E.; DeLuca, Samuel; Pelagalli, Ryan

    2014-01-01

    Hybrid gears have been tested consisting of metallic gear teeth and shafting connected by composite web. Both free vibration and dynamic operation tests were completed at the NASA Glenn Spur Gear Fatigue Test Facility, comparing these hybrid gears to their steel counterparts. The free vibration tests indicated that the natural frequency of the hybrid gear was approximately 800 Hz lower than the steel test gear. The dynamic vibration tests were conducted at five different rotational speeds and three levels of torque in a four square test configuration. The hybrid gears were tested both as fabricated (machined, composite layup, then composite cure) and after regrinding the gear teeth to the required aerospace tolerance. The dynamic vibration tests indicated that the level of vibration for either type of gearing was sensitive to the level of load and rotational speed.

  8. Galvanic Replacement of the Liquid Metal Galinstan.

    Science.gov (United States)

    Hoshyargar, Faegheh; Crawford, Jessica; O'Mullane, Anthony P

    2017-02-01

    The galvanic replacement reaction is a highly versatile approach for the creation of a variety of nanostructured materials. However, the majority of reports are limited to the replacement of metallic nanoparticles or metal surfaces. Here we extend this elegant approach and describe the galvanic replacement of the liquid metal alloy galinstan with Ag and Au. This is achieved at a macrosized droplet to create a liquid metal marble that comprises a liquid metal core and a solid metal shell, whereby the morphology of the outer shell is determined by the concentration of metallic ions used in the solution during the galvanic replacement process. In principle, this allows one to recover precious metal ions from solution in their metallic form, which are immobilized on the liquid metal and therefore easy to recover. The reaction is also undertaken at liquid metal microdroplets created via sonication to produce Ag- and Au-based galinstan nanorice particles. These materials are characterized with SEM, XRD, TEM, SAED, EDX, XPS, UV-visible spectroscopy, and open-circuit potential versus time experiments to understand the galvanic replacement process. Finally, the nanosized materials are investigated for their catalytic activity toward the reduction of methylene blue in the presence of sodium borohydride. This approach illustrates a new avenue of research for the galvanic replacement process and, in principle, could be applied to many more systems.

  9. Epitaxial growth by monolayer restricted galvanic displacement

    Directory of Open Access Journals (Sweden)

    Vasilić Rastko

    2012-01-01

    Full Text Available The development of a new method for epitaxial growth of metals in solution by galvanic displacement of layers pre-deposited by underpotential deposition (UPD was discussed and experimentally illustrated throughout the lecture. Cyclic voltammetry (CV and scanning tunneling microscopy (STM are employed to carry out and monitor a “quasi-perfect”, two-dimensional growth of Ag on Au(111, Cu on Ag(111, and Cu on Au(111 by repetitive galvanic displacement of underpotentially deposited monolayers. A comparative study emphasizes the displacement stoichiometry as an efficient tool for thickness control during the deposition process and as a key parameter that affects the deposit morphology. The excellent quality of layers deposited by monolayer-restricted galvanic displacement is manifested by a steady UPD voltammetry and ascertained by a flat and uniform surface morphology maintained during the entire growth process.

  10. Withdrawal Strength and Bending Yield Strength of Stainless Steel Nails

    Science.gov (United States)

    Douglas R. Rammer; Samuel L. Zelinka

    2015-01-01

    It has been well established that stainless steel nails have superior corrosion performance compared to carbon steel or galvanized nails in treated wood; however, their mechanical fastening behavior is unknown. In this paper, the performance of stainless steel nails is examined with respect to two important properties used in wood connection design: withdrawal strength...

  11. Methods and solutions for galvanic waste water treatment

    OpenAIRE

    Makisha Nikolay; Yunchina Maria

    2017-01-01

    Currently galvanic sludge is considered as one of the most dangerous wastes, which are formed during purification of galvanic wastewater. The slimes of galvanic production are the most toxic industrial waste and sources of heavy metals emitted into the environment. Galvanic sludge belongs to the third hazard class; these wastes need to be deposited in special landfills for toxic waste. These polygons are complex and require significant costs. In this regard, there is a need for such methods o...

  12. Experimental Design and Data collection of a finishing end milling operation of AISI 1045 steel.

    Science.gov (United States)

    Dias Lopes, Luiz Gustavo; de Brito, Tarcísio Gonçalves; de Paiva, Anderson Paulo; Peruchi, Rogério Santana; Balestrassi, Pedro Paulo

    2016-03-01

    In this Data in Brief paper, a central composite experimental design was planned to collect the surface roughness of an end milling operation of AISI 1045 steel. The surface roughness values are supposed to suffer some kind of variation due to the action of several factors. The main objective here was to present a multivariate experimental design and data collection including control factors, noise factors, and two correlated responses, capable of achieving a reduced surface roughness with minimal variance. Lopes et al. (2016) [1], for example, explores the influence of noise factors on the process performance.

  13. Characterization of solid wastes from two different hot-dip galvanizing processes; Caracterizacion de residuos solidos procedentes de dos procesos distintos de galvanizado en caliente por inmersion

    Energy Technology Data Exchange (ETDEWEB)

    Delvasto, P.; Casal-Ramos, J. a.; Gonzalez-Jordan, O.; Duran-Rodriguez, N. C.; Dominguez, J. R.; Moncada, P.

    2012-11-01

    Zinc dust and zinc ash from hot-dip galvanizing industries located in Venezuela were characterized using atomic spectroscopy, scanning electron microscopy, X-Ray diffraction and infrared spectroscopy. Dust was formed during the high-pressure drying process of the galvanized pieces, in a plant that uses a steel kettle to hold the molten zinc. Ash identified as A came from the same plant as the dust, while ash identified as B came from a hot-dip galvanizing plant which use a ceramic lined galvanizing furnace. Dust contained 98 wt % Zn, in metallic form. Both ash samples contained: Zn and ZnO, while Zn{sub 5}(OH){sub 8}Cl{sub 2}×H{sub 2}O and ZnCl{sub 2} were only found in ash B. Globally, ash “A” and ash “B” contain 71 and 75 wt % Zn, respectively. (Author)

  14. Perspectives on coated advanced high strength steels for automotive applications

    OpenAIRE

    Bhattacharya, D.

    2011-01-01

    Advanced High Strength Steels (AHSS) is the fastest growing segment of sheet products in the automotiveindustry. Coated (galvanized or galvannealed) AHSS are the most important of this class of steels. AHSSincludes various families of steels, major among them being dual-phase, multi-phase or complex-phase, TRIPand martensitic steels. Recently, Twin Induced Plasticity (TWIP) and Quenching and Partitioning (QP) steelsare also becoming popular. Finally, press-hardened steels (PHS) are increasing...

  15. FINAL REPORT: Reduction in Energy Consumption and Variability in Steel Foundry Operations

    Energy Technology Data Exchange (ETDEWEB)

    F. Peters

    2005-05-24

    This project worked to improve the efficiency of the steel casting industry by reducing the variability that occurs because of process and product variation. The project focused on the post shakeout operations since roughly half of the production costs are in this area. These improvements will reduce the amount of variability, making it easier to manage the operation and improve the competitiveness. The reduction in variability will also reduce the need for many rework operations, which will result in a direct reduction of energy usage, particularly by the reduction of repeated heat treatment operations. Further energy savings will be realized from the reduction of scrap and reduced handling. Field studies were conducted at ten steel foundries that represented the U.S. steel casting industry, for a total of over 100 weeks of production observation. These studies quantified the amount of variability, and looked toward determining the source. A focus of the data collected was the grinding operations since this is a major effort in the cleaning room, and it represents the overall casting quality. The grinding was divided into two categories, expected and unexpected. Expected grinding is that in which the location of the effort is known prior to making the casting, such as smoothing parting lines, gates, and riser contacts. Unexpected grinding, which was approximately 80% of the effort, was done to improve the surfaces at weld repair locations, to rectify burnt on sand, and other surface anomalies at random locations. Unexpected grinding represents about 80% of the grinding effort. By quantifying this effort, the project raised awareness within the industry and the industry is continuing to make improvements. The field studies showed that the amount of variation of grinding operations (normalized because of the diverse set of parts studied) was very consistent across the industry. The field studies identified several specific sources that individually contributed to

  16. Galvanic Cells: Anodes, Cathodes, Signs and Charges

    Science.gov (United States)

    Goodwin, Alan

    2011-01-01

    Electrochemistry is a difficult subject for students at school and beyond and even for their teachers. This article explores the difficult "truth" that, when a current flows from a galvanic cell, positive ions within the cell electrolyte move towards the electrode labelled positive. This seems to contravene the basic rule that like charges repel…

  17. 78 FR 24803 - Hilco SP Rail, LLC-Acquisition and Operation Exemption-RG Steel Railroad Holding, LLC

    Science.gov (United States)

    2013-04-26

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35734] Hilco SP Rail, LLC--Acquisition and Operation Exemption--RG Steel Railroad Holding, LLC Hilco SP Rail, LLC (Hilco), a noncarrier... Holding, LLC, and operate as a common carrier over an approximately 12-mile line of railroad in Sparrows...

  18. PREDICTION OF SURFACE ROUGHNESS IN END MILLING OPERATION OF DUPLEX STAINLESS STEEL USING RESPONSE SURFACE METHODOLOGY

    Directory of Open Access Journals (Sweden)

    S. D. PHILIP

    2015-03-01

    Full Text Available Response surface methodology has been used to study the effects of the machining parameters such as spindle speed, feed rate and axial depth of cut on surface roughness of duplex stainless steel in end milling operation. Dry milling experiments were conducted with three levels of spindle speed, feed rate and axial depth of cut. A mathematical model has been developed to predict the surface roughness in terms of the machining parameters using Box-Behnken design response surface methodology. The adequacy of the model was verified using analysis of variance. The prediction equation shows that the feed rate is the most important factor that influences the surface roughness followed by axial depth of cut and spindle speed. The validity of the model was verified by conducting the confirmation experiment.

  19. Vertical Soil Profiling Using a Galvanic Contact Resistivity Scanning Approach

    Directory of Open Access Journals (Sweden)

    Luan Pan

    2014-07-01

    Full Text Available Proximal sensing of soil electromagnetic properties is widely used to map spatial land heterogeneity. The mapping instruments use galvanic contact, capacitive coupling or electromagnetic induction. Regardless of the type of instrument, the geometrical configuration between signal transmitting and receiving elements typically defines the shape of the depth response function. To assess vertical soil profiles, many modern instruments use multiple transmitter-receiver pairs. Alternatively, vertical electrical sounding can be used to measure changes in apparent soil electrical conductivity with depth at a specific location. This paper examines the possibility for the assessment of soil profiles using a dynamic surface galvanic contact resistivity scanning approach, with transmitting and receiving electrodes configured in an equatorial dipole-dipole array. An automated scanner system was developed and tested in agricultural fields with different soil profiles. While operating in the field, the distance between current injecting and measuring pairs of rolling electrodes was varied continuously from 40 to 190 cm. The preliminary evaluation included a comparison of scan results from 20 locations to shallow (less than 1.2 m deep soil profiles and to a two-layer soil profile model defined using an electromagnetic induction instrument.

  20. Vertical soil profiling using a galvanic contact resistivity scanning approach.

    Science.gov (United States)

    Pan, Luan; Adamchuk, Viacheslav I; Prasher, Shiv; Gebbers, Robin; Taylor, Richard S; Dabas, Michel

    2014-07-23

    Proximal sensing of soil electromagnetic properties is widely used to map spatial land heterogeneity. The mapping instruments use galvanic contact, capacitive coupling or electromagnetic induction. Regardless of the type of instrument, the geometrical configuration between signal transmitting and receiving elements typically defines the shape of the depth response function. To assess vertical soil profiles, many modern instruments use multiple transmitter-receiver pairs. Alternatively, vertical electrical sounding can be used to measure changes in apparent soil electrical conductivity with depth at a specific location. This paper examines the possibility for the assessment of soil profiles using a dynamic surface galvanic contact resistivity scanning approach, with transmitting and receiving electrodes configured in an equatorial dipole-dipole array. An automated scanner system was developed and tested in agricultural fields with different soil profiles. While operating in the field, the distance between current injecting and measuring pairs of rolling electrodes was varied continuously from 40 to 190 cm. The preliminary evaluation included a comparison of scan results from 20 locations to shallow (less than 1.2 m deep) soil profiles and to a two-layer soil profile model defined using an electromagnetic induction instrument.

  1. Hydrogenase-catalysed deposition of vivianite on mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Silva, S. da; Basseguy, R.; Bergel, A

    2004-05-30

    A simple device was designed with two mild steel electrodes placed face to face in the same phosphate solution and coupled through an external electrical circuit. A dialysis membrane retained hydrogenase from Ralstonia eutropha in contact with one electrode only. The simultaneous measurements of the electron flux in the electrical circuit and of nicotinamide adenine dinucleotide (NADH) production catalysed by hydrogenase proved that the enzyme induced the occurrence of cathodic and anodic micro-sites on the same electrode surface. A clear galvanic current was observed, which stopped after a few hours, because of the formation of a protective film of vivianite on the electrode that was in contact with hydrogenase. Hydrogenase in phosphate solution proved to be an effective trigger of mild steel corrosion. These results may be the basis of a new and easy-to-handle hydrogenase-catalysed phosphating process, which operates under mild conditions, avoids using toxic compounds, and is quite rapid.

  2. Steel making

    CERN Document Server

    Chakrabarti, A K

    2014-01-01

    "Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

  3. 76 FR 19382 - Galvanized Steel Wire From China and Mexico

    Science.gov (United States)

    2011-04-07

    ... of the United States, that are alleged to be sold in the United States at less than fair value and... which to make an oral presentation at the conference. A nonparty who has testimony that may aid the... presentation at the conference no later than three days before the conference. If briefs or written testimony...

  4. Kinetics of fatigue crack growth and crack paths in the old puddled steel after 100-years operating time

    Directory of Open Access Journals (Sweden)

    G. Lesiuk

    2015-10-01

    Full Text Available The goal of the authors’ investigations was determination of the fatigue crack growth in fragments of steel structures (of the puddled steel and its cyclic behavior. Tested steel elements coming from the turn of the 19th and 20th were gained from still operating ancient steel construction (a main hall of Railway Station, bridges etc.. This work is a part of investigations devoted to the phenomenon of microstructural degradation and its potential influence on their strength properties. The analysis of the obtained results indicated that those long operating steels subject to microstructure degradation processes consisting mainly in precipitation of carbides and nitrides inside ferrite grains, precipitation of carbides at ferrite grain boundaries and degeneration of pearlite areas [1, 2]. It is worth noticing that resistance of the puddled steel to fatigue crack propagation in the normalized state was higher. The authors proposed the new kinetic equation of fatigue crack growth rate in such a steel. Thus the relationship between the kinetics of degradation processes and the fatigue crack growth rate also have been shown. It is also confirmed by the materials research of the viaduct from 1885, which has not shown any significant changes in microstructure. The non-classical kinetic fatigue fracture diagrams (KFFD based on deformation ( or energy (W approach was also considered. In conjunction with the results of low- and high-cycle fatigue and gradual loss of ductility as a consequence (due to the microstructural degradation processes - it seems to be a promising construction of the new kinetics fatigue fracture diagrams with the energy approach.

  5. Preparation and characterization of 304 stainless steel/Q235 carbon steel composite material

    Directory of Open Access Journals (Sweden)

    Wenning Shen

    Full Text Available The composite material of 304 stainless steel reinforced Q235 carbon steel has been prepared by modified hot-rolling process. The resulted material was characterized by scanning electron microscope, three-electrode method, fault current impact method, electrochemical potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy. The results showed that metallurgical bond between the stainless steel layer and carbon steel substrate has been formed. The composite material exhibited good electrical conductivity and thermal stability. The average grounding resistance of the composite material was about 13/20 of dip galvanized steel. There has no surface crack and bubbling formed after fault current impact. The composite material led to a significant decrease in the corrosion current density in soil solution, compared with that of hot dip galvanized steel and bare carbon steel. On the basis polarization curve and EIS analyses, it can be concluded that the composite material showed improved anti-corrosion property than hot-dip galvanized steel. Keywords: Stainless steel, Carbon steel, Anti-corrosion, Conductivity, Electrochemical, EIS

  6. Research on common methods for evaluating the operation effect of integrated wastewater treatment facilities of iron and steel enterprises

    Science.gov (United States)

    Bingsheng, Xu

    2017-04-01

    Considering the large quantities of wastewater generated from iron and steel enterprises in China, this paper is aimed to research the common methods applied for evaluating the integrated wastewater treatment effect of iron and steel enterprises. Based on survey results on environmental protection performance, technological economy, resource & energy consumption, services and management, an indicator system for evaluating the operation effect of integrated wastewater treatment facilities is set up. By discussing the standards and industrial policies in and out of China, 27 key secondary indicators are further defined on the basis of investigation on main equipment and key processes for wastewater treatment, so as to determine the method for setting key quantitative and qualitative indicators for evaluation indicator system. It is also expected to satisfy the basic requirements of reasonable resource allocation, environmental protection and sustainable economic development, further improve the integrated wastewater treatment effect of iron and steel enterprises, and reduce the emission of hazardous substances and environmental impact.

  7. Noisy galvanic vestibular stimulation modulates the amplitude of EEG synchrony patterns.

    Directory of Open Access Journals (Sweden)

    Diana J Kim

    Full Text Available Noisy galvanic vestibular stimulation has been associated with numerous cognitive and behavioural effects, such as enhancement of visual memory in healthy individuals, improvement of visual deficits in stroke patients, as well as possibly improvement of motor function in Parkinson's disease; yet, the mechanism of action is unclear. Since Parkinson's and other neuropsychiatric diseases are characterized by maladaptive dynamics of brain rhythms, we investigated whether noisy galvanic vestibular stimulation was associated with measurable changes in EEG oscillatory rhythms within theta (4-7.5 Hz, low alpha (8-10 Hz, high alpha (10.5-12 Hz, beta (13-30 Hz and gamma (31-50 Hz bands. We recorded the EEG while simultaneously delivering noisy bilateral, bipolar stimulation at varying intensities of imperceptible currents - at 10, 26, 42, 58, 74 and 90% of sensory threshold - to ten neurologically healthy subjects. Using standard spectral analysis, we investigated the transient aftereffects of noisy stimulation on rhythms. Subsequently, using robust artifact rejection techniques and the Least Absolute Shrinkage Selection Operator regression and cross-validation, we assessed the combinations of channels and power spectral features within each EEG frequency band that were linearly related with stimulus intensity. We show that noisy galvanic vestibular stimulation predominantly leads to a mild suppression of gamma power in lateral regions immediately after stimulation, followed by delayed increase in beta and gamma power in frontal regions approximately 20-25 s after stimulation ceased. Ongoing changes in the power of each oscillatory band throughout frontal, central/parietal, occipital and bilateral electrodes predicted the intensity of galvanic vestibular stimulation in a stimulus-dependent manner, demonstrating linear effects of stimulation on brain rhythms. We propose that modulation of neural oscillations is a potential mechanism for the previously

  8. Evaluation of Galvanic Vestibular Stimulation System

    Science.gov (United States)

    Kofman, I. S.; Warren, E.; DeSoto, R.; Moroney, G.; Chastain, J.; De Dios, Y. E.; Gadd, N.; Taylor, L.; Peters, B. T.; Allen, E.; hide

    2017-01-01

    Microgravity exposure results in an adaptive central reinterpretation of information from multiple sensory sources to produce a sensorimotor state appropriate for motor actions in this unique environment, but this new adaptive state is no longer appropriate for the 1-g gravitational environment on Earth. During these gravitational transitions, astronauts experience deficits in both perceptual and motor functions including impaired postural control, disruption in spatial orientation, impaired control of locomotion that include alterations in muscle activation variability, modified lower limb kinematics, alterations in head-trunk coordination as well as reduced dynamic visual acuity. Post-flight changes in postural and locomotor control might have adverse consequences if a rapid egress was required following a long-duration mission, where support personnel may not be available to aid crewmembers. The act of emergency egress includes, but is not limited to standing, walking, climbing a ladder, jumping down, monitoring displays, actuating discrete controls, operating auxiliary equipment, and communicating with Mission Control and recovery teams while maintaining spatial orientation, mobility and postural stability in order to escape safely. The average time to recover impaired postural control and functional mobility to preflight levels of performance has been shown to be approximately two weeks after long-duration spaceflight. The postflight alterations are due in part to central reinterpretation of vestibular information caused by exposure to microgravity. In this study we will use a commonly used technique of transcutaneous electrical stimulation applied across the vestibular end organs (galvanic vestibular stimulation, GVS) to disrupt vestibular function as a simulation of post-flight disturbances. The goal of this project is an engineering human-in-the-loop evaluation of a device that can degrade performance of functional tasks (e.g. to maintain upright balance

  9. Comparison of galvanic displacement and electroless methods for ...

    Indian Academy of Sciences (India)

    Abstract. Gold nanoparticles have been deposited on synthetic calcite substrate by galvanic displacement reaction and electroless deposition methods. A comparative study has shown that electroless deposition is superior compared to galvanic displacement reaction for uniform deposition of gold nanoparticles on calcite.

  10. Metallurgical characterization, galvanic corrosion, and ionic release of orthodontic brackets coupled with Ni-Ti archwires.

    Science.gov (United States)

    Darabara, Myrsini S; Bourithis, Lefteris I; Zinelis, Spiros; Papadimitriou, George D

    2007-04-01

    In orthodontics, a combination of metallic alloys is placed into the oral cavity during medical treatment and thus the corrosion resistance and ionic release of these appliances is of vital importance. The aim of this study is to investigate the elemental composition, microstructure, hardness, corrosion properties, and ionic release of commercially available orthodontic brackets and Copper Ni-Ti archwires. Following the assessment of the elemental composition of the orthodontic wire (Copper Ni-Ti) and the six different brackets (Micro Loc, Equilibrium, OptiMESH(XRT), Gemini, Orthos2, and Rematitan), cyclic polarization curves were obtained for each material to estimate the susceptibility of each alloy to pitting corrosion in 1M lactic acid. Galvanic corrosion between the orthodontic wire and each bracket took place in 1M lactic acid for 28 days at 37 degrees C and then the ionic concentration of Nickel and Chromium was studied. The orthodontic wire is made up from a Ni-Ti alloy with copper additions, while the orthodontic brackets are manufactured by different stainless steel grades or titanium alloys. All tested wires and brackets with the exception of Gemini are not susceptible to pitting corrosion. In galvanic corrosion, following exposure for 28 days, the lowest potential difference (approximately 250 mV) appears for the orthodontic wire Copper Ni-Ti and the bracket made up from pure titanium (Rematitan) or from the stainless steel AISI 316 grade (Micro Loc). Following completion of the galvanic corrosion experiments, measurable quantities of chromium and nickel ions were found in the residual lactic acid solution. (c) 2006 Wiley Periodicals, Inc.

  11. Galvanic vestibular stimulation speeds visual memory recall.

    Science.gov (United States)

    Wilkinson, David; Nicholls, Sophie; Pattenden, Charlotte; Kilduff, Patrick; Milberg, William

    2008-08-01

    The experiments of Alessandro Volta were amongst the first to indicate that visuo-spatial function can be altered by stimulating the vestibular nerves with galvanic current. Until recently, the beneficial effects of the procedure were masked by the high levels of electrical current applied, which induced nystagmus-related gaze deviation and spatial disorientation. However, several neuropsychological studies have shown that much weaker, imperceptible currents that do not elicit unpleasant side-effects can help overcome visual loss after stroke. Here, we show that visual processing in neurologically healthy individuals can also benefit from galvanic vestibular stimulation. Participants first learnt the names of eight unfamiliar faces and then after a short delay, answered questions from memory about how pairs of these faces differed. Mean correct reaction times were significantly shorter when sub-sensory, noise-enhanced anodal stimulation was administered to the left mastoid, compared to when no stimulation was administered at all. This advantage occurred with no loss in response accuracy, and raises the possibility that the procedure may constitute a more general form of cognitive enhancement.

  12. Mössbauer and XRD study of hot dip galvanized alloy

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, E., E-mail: kuzmann@caesar.elte.hu [Eötvös Loránd University, Institute of Chemistry (Hungary); Speakman, R.; El-Sharif, M. [Glasgow Caledonian University (United Kingdom); Stichleutner, S.; Homonnay, Z. [Eötvös Loránd University, Institute of Chemistry (Hungary); Klencsár, Z. [Research Centre for Natural Sciences, HAS, Institute of Materials and Environmental Chemistry (Hungary); Sziráki, L. [Eötvös Loránd University, Institute of Chemistry (Hungary); Chisholm, C. U.; Lak, Gy. B. [Glasgow Caledonian University (United Kingdom)

    2016-12-15

    Mössbauer spectroscopy has been used to investigate the nature of the Zinc-Iron alloys present within the Hot Dip Galvanized (HDG) layers of steel with a silicon content of 0.35 %. The investigation also studied the impact of the powder coating pretreatment on the nature of the alloy layers. The acid etching process within the pretreatment process in particular would be expected to have a significant impact on the HDG layer. This study utilized {sup 57}Fe Mössbauer spectroscopy to examine identically processed samples prior to and post pre treatment. XRD and {sup 57}Fe CEMS measurements were performed on hot galvanized S355J2 + N samples, forming sandwiched structure. Both XRD and CEMS reveal the presence of dominant steel phase in accordance with its estimated occurrence on the surface of the sandwiched samples. Minor Γ-Fe3Zn10, ζ-FeZn15 and solid solution Fe-Zn as well as minor Fe-Si phases could also be identified.

  13. Economical and technological study of surface grinding versus face milling in hardened AISI D3 steel machining operations

    OpenAIRE

    Vila Pastor, Carlos; Siller, H.R.; Rodríguez, C.A.; BRUSCAS BELLIDO, GRACIA-MARIA; Serrano, J.

    2012-01-01

    This work deals with the technological and economic considerations required to select face milling vs. surface grinding operations in the manufacture of hardened steel flat surfaces for dies and moulds. In terms of technological considerations, factors such as component geometry, material and surface quality (dimensional tolerance and surface finish) are taken into account. The economic considerations include the cost of machine depreciation, labour and consumables (cutting tools in face mill...

  14. 49 CFR 192.328 - Additional construction requirements for steel pipe using alternative maximum allowable operating...

    Science.gov (United States)

    2010-10-01

    ... experienced failures indicative of systemic material defects during strength testing, including initial... 49 Transportation 3 2010-10-01 2010-10-01 false Additional construction requirements for steel... Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY...

  15. Potentiometric titration of zinc and cadmium in electrolytes of in galvanic baths

    International Nuclear Information System (INIS)

    Kosyuga, E.A.; Kalugin, A.A.; Gur'ev, I.A.

    1979-01-01

    The method of potentiometric titration of zinc and cadmium by complexone 3 in electrolytes of galvanic baths using sulphide - silver electrode for determining the finite point of titration is suggested. Copper (2) ions are proposed as indicator ions. The potentiometric determination should be performed at pH=10. The method is verified on model electrolyte solutions and on the electrolyte solutions of operating baths.The technique can be used for automatic control. The time for analysis is 10 minutes

  16. Corrosion Behavior and Oxide Film Formation of T91 Steel under Different Water Chemistry Operation Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D. Q.; Shi, C.; Li, J.; Gao, L. X. [Shanghai University of Electric Power, Shanghai (China); Lee, K. Y. [Dalian University of Technology, Dalian (China)

    2017-02-15

    The corrosion behavior of a ferritic/martensitic steel T91 exposed to an aqueous solution containing chloride and sulfate ions is investigated depending on the stimulated all-volatile treatment (AVT) and under oxygenated treatment (OT) conditions. The corrosion of T91 steel under OT condition is severe, while the corrosion under AVT condition is not. The co-existence of chloride and sulfate ions has antagonistic effect on the corrosion of T91 steel in both AVT and OT conditions. Unlike to corrosion resistance in the aqueous solution, OT pretreatment provides T91 steel lower oxidation-resistance than VAT pretreatment. From scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis, the lower corrosion resistance in the aqueous solution by VAT conditions possibly is due to the formation of pits. In addition, the lower oxidation resistance of T91 steel pretreated by OT conditions is explained as follows: the cracks formed during the immersion under OT conditions accelerated peeling-off rate of the oxide film.

  17. MICROSTRUCTURE AND MECHANICAL PROPERTIES DEGRADATION OF CrMo CREEP RESISTANT STEEL OPERATING UNDER CREEP CONDITIONS

    Directory of Open Access Journals (Sweden)

    Ján Micheľ

    2011-07-01

    Full Text Available In this contribution microstructure degradation of a steam tube is analysed. The tube is made of CrMo creep resistant steel and was in service under creep conditions at temperature 530°C and calculated stress level in the tube wall 46.5 MPa. During service life in the steel gradual micro structure changes were observed, first pearlite spheroidization, precipitation, coagulation and precipitate coarsening. Despite the fact that there were evident changes in the micro structure the strength and deformation properties of the steel (Re, Rm, A5, Z, the resistance to brittle fracture and the creep strength limit, were near to unchanged after 2.1x10 5 hours in service. The steam tube is now in service more than 2.6x10 5 h.

  18. The possibilities for reuse of steel scrap in order to obtain blades for knives

    International Nuclear Information System (INIS)

    Štrbaca, N.; Markovića, I.; Mitovskia, A.; Balanovića, L.; Živkovića, D.; Grekulović, V.

    2017-01-01

    The purpose of this study is to determine fracture toughness of Resistance Spot Welded (RSW) Dual Phase (DP) steels. RSW of galvanized and ungalvanized DP 450 steel sheets was carried out on spot welding machine. Fracture toughness of RSW joints of galvanized and ungalvanized DP 450 steel sheets was calculated from tensile-shear tests. New empirical equations were developed using Least Squares Method (LSM) between energy release rate, fracture toughness and critical crack size depending on the relationship between hardness and fracture toughness values. Results indicated that fracture toughness of joints welded by using RSW increased exponentially while the hardness decreased. In addition, fracture toughness and energy release rate of RSW galvanized DP 450 steel sheets were lower compared to RSW ungalvanized DP 450 steel sheets which had approximately the same hardness. [es

  19. Evaluation of Radiation Exposure during Construction and Operation of Concrete Bridge Reinforced with Very Low Level Radioactive Steel

    International Nuclear Information System (INIS)

    Panik, M.; Necas, V.

    2012-01-01

    A lot of nuclear power plants are approaching the end of their lifetime and they will be phased out. Decommissioning of these nuclear power plants involve complete dismantling of technologies and demolition of buildings. During this process it is produced plenty of waste material of different categories. Significant portion of decommissioning materials comprise radionuclides what is caused by contamination and activation processes mostly from the operational period of nuclear power plant. Attention in this paper is paid to waste steel from the decommissioning of nuclear power plants with the specific activity just slightly exceeding legislation limits for the unconditional release into the environment. From the traditional point of view this material should be treated, conditioned and disposed on the radioactive waste repository. Second possibility is to release this material conditionally and reuse it in chosen industrial application. Very low level radioactive steel scrap should be melted and melting products should be processed into products that can be applied in industry. First option requires considerable financial investment, human resources and repository capacity. Second option saves some financial funds and it enables to reuse and save potentially valuable material for the future. Paper comprises evaluation of external and internal exposure during construction and operation of concrete bridges that utilize very low level radioactive steel as part of their reinforcement. Two models of representative concrete bridges were created. External gamma exposure and exposure from inhalation and ingestion of radionuclides were calculated using suitable computational tools. VISIPLAN 3D ALARA planning tool was chosen for the calculation of external gamma exposure. Software GOLDSIM enables to calculate transport of radionuclides initially contained in conditionally released reinforcement steel through subsoil and sequential exposure of people caused by inhalation of

  20. Relation Between the Structural Components and Nonmetallic Inclusions and the Operating Properties of Bearing Steel

    Science.gov (United States)

    Moroz, A. N.; Glotka, A. A.

    2018-01-01

    The endurance of bearing steel ShKh15SG under cyclic bending tests is studied. The relation between the cyclic bending frequency and the ultimate bending strength is determined. It is shown that the endurance calculated by the prototype method does not match the results of full-scale tests of bearings. A new method for determining the endurance of bearings from steel ShKh15SG allowing for the distribution of nonmetallic inclusions in the carbide bands and outside them is suggested.

  1. Prevention of radioactivity in steel. Necessity of an international co-operation between industry and government

    International Nuclear Information System (INIS)

    Amedro, G.

    1999-01-01

    European steel companies will not melt radioactive contaminated scrap, even if it would be allowed to do so by legislation and proposed clearance levels. Scrap delivering companies as well as steel producing companies are well armed with scrap charge control. Additional control during steelmaking is given by analysing a crude steel sample of each heat. Regulations regarding health criteria are available on national and European level (RP43 and RP89) but are not usable in practice for the control of scrap. Problems which are at present left to be solved by each site equipped with a means of detection cover principally the following areas: Definition and detection of abnormal radioactivity without identification of the radioactive element; Common definition of alarm thresholds by suppliers and customers; Emergency isolation measures for suspect vehicles (e.g. immediate return or quarantine), notably involving illicit material from a third country; Identification, isolation, handling and destination of discovered radioactive products; Financing of associated costs; Public relations; Preventive actions. It seems to be necessary to produce a benchmark for the activity level in finished steel to determine the actual level of 'normal radioactivity' in the European steel pool. A comparison of the actual state of the art in the European steel industry due to the measures already taken would be useful. The present situation can only be efficiently improved by action in common. Industry has made large investments in detection equipment and in staff training. It has now practical experience. Additional regulatory provisions and appropriate logistical means are now awaited from government, i.e. concerning technical know-how and expertise, properly adapted equipment and in certain cases financial intervention. European directives should not constitute an impediment and should, if necessary, be adapted to needs. When the situation is clarified, future regular checks will be an

  2. Analysis of Postural Control Adaptation During Galvanic and Vibratory Stimulation

    National Research Council Canada - National Science Library

    Fransson, P

    2001-01-01

    The objective for this study was to investigate whether the postural control adaptation during galvanic stimulation of the vestibular nerve were similar to that found during vibration stimulation to the calf muscles...

  3. Forming of High-strength Steels Using a Hot-melt Dry Lubricant

    DEFF Research Database (Denmark)

    Hörnström, Sven-Erik; Karlsson, Erik; Olsson, Mikael

    2008-01-01

    steel grades and improved surface engineering treatments such as the deposition of low friction CVD and PVD coatings. In the present study the performance of a hot-melt dry lubricant in the forming of hot and cold rolled and hot-dip galvanized high strength steel has been evaluated and compared...

  4. 78 FR 44532 - Steel Threaded Rod From India: Initiation of Countervailing Duty Investigation

    Science.gov (United States)

    2013-07-24

    ... Checklist''), at Attachment II, Analysis of Industry Support for the Petitions Covering Steel Threaded Rod..., zinc coating (i.e., galvanized, whether by electroplating or hot- dipping), paint, and other similar... injury to, the domestic industry producing steel threaded rod in the United States. Also, consistent with...

  5. Stress-corrosion cracking of steels in ammonia with consideration given to OTEC design: a survey

    Energy Technology Data Exchange (ETDEWEB)

    Teel, R.B.

    1980-03-01

    Carbon steel, alloy steel, and high-strength, quenched and tempered steel, when under applied or residual stress and especially when cold formed and/or welded without subsequent thermal stress relief, are subject to failure by stress-corrosion cracking (SCC) in air-contaminated dry ammonia. Water as well as hydrazine when present in small amounts have been shown to be effective inhibitors in an all steel system. Galvanic corrosion between dissimilar metals and/or accelerated failure by SCC of stressed steel as a result of galvanic coupling may be of concern. Where water has proven effective as an inhibitor of SCC in an all steel system, it may not be adequate in a mixed metal system. With aluminum tubes, the tube sheet will either have to be solid aluminum, aluminum clad steel or some nonconductive coating will be necessary to effectively remove the cathodic alloy from the galvanic circuit. Research is required to determine the severity of the coupling effect between dissimilar alloys in ammonia under OTEC conditions; especially the possibility of accelerated SCC failures of stressed steel where the presence of an inhibitor in the ammonia may not be sufficient to override the galvanic coupling effect.

  6. Intermetallic Cu3Sn Phase Layer on Electrode’s Tip of Galvanized Resistance Spot Welding

    Directory of Open Access Journals (Sweden)

    Muhammad Anis

    2010-10-01

    Full Text Available A resistance spot welding method is commonly used in automotive industries application. In a resistance spot welding method, the copper electrode has a significant role as an electric current carrier for joining thin metal sheet. This research was focused on studying the effect of tin layer at the electrode tip for joining galvanized steel sheet. The main variable of this research is in the thickness of the intermetallic Cu3Sn layer. The result showed that the introduction of tin layer less than 1 μm in thickness on the electrode tip gives a comparable shear strength and nugget diameter distribution with the unplated electrode tip.

  7. Factors Affecting Optimal Surface Roughness of AISI 4140 Steel in Turning Operation Using Taguchi Experiment

    Science.gov (United States)

    Novareza, O.; Sulistiyarini, D. H.; Wiradmoko, R.

    2018-02-01

    This paper presents the result of using Taguchi method in turning process of medium carbon steel of AISI 4140. The primary concern is to find the optimal surface roughness after turning process. The taguchi method is used to get a combination of factors and factor levels in order to get the optimum surface roughness level. Four important factors with three levels were used in experiment based on Taguchi method. A number of 27 experiments were carried out during the research and analysed using analysis of variance (ANOVA) method. The result of surface finish was determined in Ra type surface roughness. The depth of cut was found to be the most important factors for reducing the surface roughness of AISI 4140 steel. On the contrary, the other important factors i.e. spindle speed and rake side angle of the tool were proven to be less factors that affecting the surface finish. It is interesting to see the effect of coolant composition that gained the second important factors to reduce the roughness. It may need further research to explain this result.

  8. Proposal for an alternative operative method for determination of polarisation resistance for the quantitative evaluation of corrosion of reinforcing steel in concrete cooling towers

    Energy Technology Data Exchange (ETDEWEB)

    Mitzithra, M.E., E-mail: me.mitzithra@gmail.com [EDF R& D, 6 quai Watier, 78401 Chatou Cedex (France); Université de Toulouse, UPS, INSA, LMDC, 135, Avenue de Rangueil, 31077 Toulouse Cedex 4 (France); Deby, F.; Balayssac, J.P. [Université de Toulouse, UPS, INSA, LMDC, 135, Avenue de Rangueil, 31077 Toulouse Cedex 4 (France); Salin, J. [EDF R& D, 6 quai Watier, 78401 Chatou Cedex (France)

    2015-07-15

    This paper summarises the results obtained from numerical simulations of an operational measurement mode of polarisation resistance adapted for evaluating corrosion of reinforcing steel in concrete on cooling towers. A simple operational measurement mode of R{sub p} is proposed, adapted for cooling towers prone to corrosion due to carbonation. By means of numerical experimentations, calculation diagrams and semi-empirical equations are built involving the different influencing parameters: concrete cover to steel reinforcement, concrete resistivity and current intensity injected from the counter electrode. Finally, a first application of the proposed procedure for calculating the real value of R{sub p} in laboratory conditions is presented.

  9. Environmental assessment of the hot-dip galvanization processes

    Directory of Open Access Journals (Sweden)

    T. Karkoszka

    2017-01-01

    Full Text Available Processes of the hot-dip galvanization, refraining from application of dangerous chemical substances together with the necessity of ensuring the high temperatures, both pose a special threat to the environment. Therefore, the subject of analysis was environmental impact of the hot-dip galvanization process. Here has been done the identification and the assessment of the environmental aspects as well as has been pointed at the key-aspects requiring the special supervision. The developed assessment methodology can be applied by each of the organization wanting to master the processes by minimizing their environmental influence.

  10. Steel bridges structural health monitoring based on operational modal analysis accommodating evaluation of uncertainty

    Directory of Open Access Journals (Sweden)

    Saeid Jahan

    2017-11-01

    Full Text Available Structural damage detection is based on that the dynamic response of structure will change because of damage. Hence, it is possible to estimate the location and severity of damage leads to changes in the dynamic response before and after the damage. In this study, the genetic fuzzy system has been used for bridge structural health monitoring. A key objective of using genetic algorithms is to automate the design of fuzzy systems. This method is used for damage detection of a single span railway bridge with steel girders and a concrete bridge. For studying damage detection, the numerical models of these two bridges are built with the measured dynamic characteristics. A three-dimensional finite element model and a single two-dimensional girders model of the bridge have been constructed to study usefulness of the genetic fuzzy system for damage detection and the effectiveness of modeling. After analysis to control the uncertainties, the measured frequencies are contaminated with some noise and the effect of that on the achievement of damage detection method is evaluated. The present study has shown that the natural frequency has appropriate sensitivity to different damage scenarios in the structure. In addition, the natural frequency in comparison with other modal parameters, is less affected by random noise. Increasing the number of measurement modes and using torsional modes, will lead to an accurate damage diagnosis even in symmetrical structures.

  11. Characterization of Coatings on Steel Self-Piercing Rivets for Use with Magnesium Alloys

    Science.gov (United States)

    McCune, Robert C.; Forsmark, Joy H.; Upadhyay, Vinod; Battocchi, Dante

    Incorporation of magnesium alloys in self-pierce rivet (SPR) joints poses several unique challenges among which are the creation of spurious galvanic cells and aggravated corrosion of adjacent magnesium when coated steel rivets are employed. This work firstly reviews efforts on development of coatings to steel fasteners for the diminution of galvanic corrosion when used with magnesium alloys. Secondly, approaches, based on several electrochemical methods, for the measurement of the galvanic-limiting effect of a number of commercially-available coatings to hardened 10B37 steel self-piercing rivets inserted into alloy couples incorporating several grades of magnesium are reported. Electrochemical impedance spectroscopy (EIS), zero-resistance ammeter (ZRA), corrosion potential and potential-mapping visualization methods (e.g. scanning vibrating electrode technique — SVET) are illustrated for the several rivet coatings considered.

  12. Intraoral galvanic corrosion: literature review and case report.

    Science.gov (United States)

    Meyer, R D; Meyer, J; Taloumis, L J

    1993-02-01

    This article reviewed the dental history of a patient with symptomatic electro-chemical reactions after the occlusal relationship of an existing complete gold crown and silver amalgam restoration was changed. A literature review of oral galvanism is presented with diagnostic techniques and treatment options.

  13. An Easy-to-Assemble Three-Part Galvanic Cell

    Science.gov (United States)

    Eggen, Per-Odd; Skaugrud, Brit

    2015-01-01

    The galvanic cell presented in this article is made of only three parts, is easy to assemble, and can light a red light emitting diode (LED). The three cell components consist of a piece of paper with copper sulfate, a piece of paper with sodium sulfate, and a piece of magnesium ribbon. Within less than 1 h, students have time to discuss the…

  14. Dissolved oxygen detection by galvanic displacement-induced ...

    Indian Academy of Sciences (India)

    This paper proposed a simple, efficient and sensitive electrochemical sensor for dissolved oxygen (DO) detection based on a galvanic displacement synthesized reduced graphene oxide–silver nanoparticles (RGO/Ag) composite modified grassy carbon electrode (GCE). The synthesized RGO/Ag nanocomposite was ...

  15. Effects of galvanic distortions on magnetotelluric data: Interpretation ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    quasi-static character that causes vertical shifts in MT apparent resistivity curves called “static shift”. The static shift does not have any effects on the phase variations. Usually the galvanic effects are found to be dominant in MT data except the strong induction effects obtained near deep elon- gated depression filled with ...

  16. Ferritic stainless steel composite slabs : Experimental study of longitudinal shear transfer

    OpenAIRE

    Ferrer Ballester, Miquel; Marimón Carvajal, Federico; Arrayago Luquin, Itsaso; Mirambell Arrizabalaga, Enrique

    2014-01-01

    The objective of this work is to carry out the procedure described in Eurocode 4 to evaluate the longitudinal shear transfer capability of conventional steel sheeting open-rib profile with embossments, usually rolled in conventional galvanized steel, being rolled now in ferritic stainless steel 1.4003 alloy. Finally, the results of both composite floor slabs are compared. Two methodologies have been used to evaluate the longitudinal shear resistance in composite slabs, the m-k method and t...

  17. Designing High Performance Steel Castings Today: Proceedings of the Steel Founders Society of America, Technical and Operating Conference December 7-10, 2016Chicago, IL

    Science.gov (United States)

    2016-12-10

    property values. Two (2) standard round tensile specimens shall be manufactured and tested per ASTM E8/E8M and two (2) charpy V-notch specimens...Mo alloy steels ): Yield strength (0.1% offset) – 140/160 ksi Reduction in Area – 30% min. Charpy V-Notch resistance @ - 40 +/- 20F – 20 ft-lb...

  18. Ultrasonic imaging of defects in coarse-grained steels with the decomposition of the time reversal operator.

    Science.gov (United States)

    Lopez Villaverde, Eduardo; Robert, Sébastien; Prada, Claire

    2016-07-01

    In the present work, the Synthetic Transmit Aperture (STA) imaging is combined with the Decomposition of the Time Reversal Operator (DORT) method to image a coarse grained austenitic-ferritic steel using a contact transducer array. The highly heterogeneous structure of this material produces a strong scattering noise in ultrasound images. Furthermore, the surface waves guided along the array interfere with the bulk waves backscattered by defects. In order to overcome these problems, the DORT method is applied before calculating images with the STA algorithm. The method consists in analyzing in the frequency domain the singular values and singular vectors of the full array transfer matrix. This paper first presents an analysis of the singular values of different waves contained in the data acquisition, which facilitates the identification of the subspace associated with the surface guided waves for filtering operations. Then, a filtered matrix is defined where the contribution of structural noise and guided waves are reduced. Finally, in the time domain, the STA algorithm is applied to this matrix in order to calculate an image with reduced structural noise. Experiments demonstrate that this filtering improves the signal-to-noise ratio by more than 12 dB in comparison with the STA image before filtering.

  19. Whisker Formation On Galvanic Tin Surface Layer

    Directory of Open Access Journals (Sweden)

    Radanyi A.L.

    2015-06-01

    Full Text Available The present work reports the effect of substrate composition, thickness of the tin electroplate and its morphology on pressure-induced tin whisker formation. Pure tin deposits of different thickness were obtained on a copper and brass substrates using methane sulfonic industrial bath. The deposits were compressed by a steel bearing ball forming imprint on the surface. The microstructure of tin whiskers obtained at the boundary of each imprint, their length and number were studied using both light and scanning electron microscopy. It was shown that the most intensive formation and growth of whiskers was observed in the first two hours. In general, brass substrate was shown to be more prone to whisker formation than copper independently of the tin coating thickness. The results have been compared with industrial bright tin finish on control unit socket leads and proposals have been made as to modification of the production process in order to minimize the risk of whiskering.

  20. Ion Release and Galvanic Corrosion of Different Orthodontic Brackets and Wires in Artificial Saliva.

    Science.gov (United States)

    Tahmasbi, Soodeh; Sheikh, Tahereh; Hemmati, Yasamin B

    2017-03-01

    To investigate the galvanic corrosion of brackets manufactured by four different companies coupled with stainless steel (SS) or nickel-titanium (NiTi) wires in an artificial saliva solution. A total of 24 mandibular central incisor Roth brackets of four different manufacturers (American Orthodontics, Dentaurum, Shinye, ORJ) were used in this experimental study. These brackets were immersed in artificial saliva along with SS or NiTi orthodontic wires (0.016'', round) for 28 days. The electric potential difference of each bracket/ wire coupled with a saturated calomel reference electrode was measured via a voltmeter and recorded constantly. Corrosion rate (CR) was calculated, and release of ions was measured with an atomic absorption spectrometer. Stereomicroscope was used to evaluate all samples. Then, samples with corrosion were further assessed by scanning electron microscope and energy-dispersive X-ray spectroscopy. Two-way analysis of variance was used to analyze data. Among ions evaluated, release of nickel ions from Shinye brackets was significantly higher than that of other brackets. The mean potential difference was significantly lower in specimens containing a couple of Shinye brackets and SS wire compared with other specimens. No significant difference was observed in the mean CR of various groups (p > 0.05). Microscopic evaluation showed corrosion in two samples only: Shinye bracket coupled with SS wire and American Orthodontics bracket coupled with NiTi wire. Shinye brackets coupled with SS wire showed more susceptibility to galvanic corrosion. There were no significant differences among specimens in terms of the CR or released ions except the release of Ni ions, which was higher in Shinye brackets.

  1. Performance evaluation of NEEM oil and HONGE Oil as cutting fluid in drilling operation of mild steel

    Science.gov (United States)

    Jyothi, P. N.; Susmitha, M.; Sharan, P.

    2017-04-01

    Cutting fluids are used in machining industries for improving tool life, reducing work piece and thermal deformation, improving surface finish and flushing away chips from the cutting zone. Although the application of cutting fluids increases the tool life and Machining efficiency, but it has many major problems related to environmental impacts and health hazards along with recycling & disposal. These problems gave provision for the introduction of mineral, vegetable and animal oils. These oils play an important role in improving various machining properties, including corrosion protection, lubricity, antibacterial protection, even emulsibility and chemical stability. Compared to mineral oils, vegetable oils in general possess high viscosity index, high flash point, high lubricity and low evaporative losses. Vegetable oils can be edible or non-edible oils and Various researchers have proved that edible vegetable oils viz., palm oil, coconut oil, canola oil, soya bean oil can be effectively used as eco-friendly cutting fluid in machining operations. But in present situations harnessing edible oils for lubricants formation restricts the use due to increased demands of growing population worldwide and availability. In the present work, Non-edible vegetable oil like Neem and Honge are been used as cutting fluid for drilling of Mild steel and its effect on cutting temperature, hardness and surface roughness are been investigated. Results obtained are compared with SAE 20W40 (petroleum based cutting fluid)and dry cutting condition.

  2. EVALUATION AND ACTIONS OF CLEANER PRODUCTION IN GALVANIC INDUSTRY OF THE VILLA CLARA PROVINCE

    Directory of Open Access Journals (Sweden)

    Petra G. Velazco Pedroso

    2015-10-01

    Full Text Available In this paper, the assessment results accomplished in different processes of the galvanic industry are presented and it is taking into account the application of good practices and measures of Cleaner Production. The main critical points in the processes of metallic coating were identified; and the characterization of the effluents generated by the installation is done. A number of technological changes in the processes are proposed, as well as the introduction of cleaner production measures which contribute to increase the efficiency and safety of processes, reduce risks and improvements to internal operations. It provides advantages of economic, environmental and social nature for the galvanic industry due to the minimizing of the impacts on environment, because the sewage and its pollutant load are reduced. Besides, we can save water, energy and raw materials. The economic evaluation showed the feasibility of applying the Cleaner Production (PML measures proposed with a Net Present Value (NPV of $109 696.26, and an Internal Rate of Return (IRR of 64 % value and payback period lower than two years.

  3. Clinical management of galvanic current between gold and amalgam.

    Science.gov (United States)

    Williamson, R

    1996-01-01

    Placing a strip of rubber dam or similar insulator between the contacting dissimilar restorations is a diagnostic technique for relieving and evaluating painful galvanic currents. Treatment modalities vary according to severity of pain. In cases of little or no pain, nothing is done, and corrosion products are allowed to form an insulating cover over the offending restoration. For patients with severe pain that does not improve, treatment may consist of placing a composite restoration in the amalgam restoration to break the interproximal dissimilar-metal contact. For painful currents caused by occluding restorations, a coating of unfilled light-cured resin over the offending amalgam breaks the metal contact and allows corrosion product buildup. Galvanic currents can occur and cause pain, but this is generally shortlived and should not influence the dentist's choice of an appropriate restorative material.

  4. Silver matrix composites reinforced with galvanically silvered particles

    OpenAIRE

    J. Śleziona; J. Wieczorek,

    2007-01-01

    Purpose: The paper presents the possibility of the application of metalic layers drifted with the use of the galvanic methods on the ceramic particles surface. The application of the layers was aimed at obtaining the rewetting of the reinforcing particles with the liquid silver in the course of the producing of silver matrix composites with the use of mechanical stirring method. To enable introducing of the iron powder and glass carbon powder to liquid silver the solution of covering the powd...

  5. Use of Galvanic Vestibular Feedback for a Balance Prosthesis

    OpenAIRE

    Peterka, Robert J.

    2012-01-01

    Activation of vestibular afferents by a bilateral bipolar galvanic vestibular stimulus (GVS) evokes medial-lateral (ML) body sway. By applying a GVS feedback signal that is a function of measured ML head motion, the potential exists for GVS to restore a useful vestibular contribution to ML balance control in vestibular-deficient subjects who remain responsive to GVS. A key to developing an effective balance prosthesis using GVS is to determine the functional relationship between GVS and its i...

  6. Malayaite ceramic pigments prepared with galvanic sludge as colouring agent

    OpenAIRE

    Costa, Gracia; Ribeiro, Manuel J.; Labrincha, Joao A.; Dondi, Michele; Matteucci, Francesco; Cruciani, Giuseppe

    2008-01-01

    The synthesis and characterisation of chrome?-tin red malayaite Ca(Cr,Sn)SiO5 pigments are reported. The novel approach of using a galvanizing sludge from the Cr/Ni plating process as colouring agent is investigated. The ceramic pigments were prepared using common solid state reaction process, with optimisation of milling and firing conditions. Characterisation was done by x-?ray powder diffraction, diffuse reflectance spectroscopy, and application in standard ceramic glazes. The ceramic pigm...

  7. Reprocessing of zinc galvanic waste sludge by selective precipitation

    Czech Academy of Sciences Publication Activity Database

    Jandová, J.; Maixner, J.; Grygar, Tomáš

    2002-01-01

    Roč. 46, č. 2 (2002), s. 52-55 ISSN 0862-5468 R&D Projects: GA AV ČR IBS4032004; GA ČR GA203/99/0067 Institutional research plan: CEZ:AV0Z4032918; CEZ:MSM 223100002 Keywords : galvanic sludge * recovery * zinc Subject RIV: CA - Inorganic Chemistry Impact factor: 0.354, year: 2002

  8. A Galvanic Coupling Method for Assessing Hydration Rates

    Directory of Open Access Journals (Sweden)

    Clement Ogugua Asogwa

    2016-07-01

    Full Text Available Recent advances in biomedical sensors, data acquisition techniques, microelectronics and wireless communication systems opened up the use of wearable technology for ehealth monitoring. We introduce a galvanic coupled intrabody communication for monitoring human body hydration. Studies in hydration provide the information necessary for understanding the desired fluid levels for optimal performance of the body’s physiological and metabolic processes during exercise and activities of daily living. Current measurement techniques are mostly suitable for laboratory purposes due to their complexity and technical requirements. Less technical methods such as urine color observation and skin turgor testing are subjective and cannot be integrated into a wearable device. Bioelectrical impedance methods are popular but mostly used for estimating total body water with limited accuracy and sensitive to 800 mL–1000 mL change in body fluid levels. We introduce a non-intrusive and simple method of tracking hydration rates that can detect up to 1.30 dB reduction in attenuation when as little as 100 mL of water is consumed. Our results show that galvanic coupled intrabody signal propagation can provide qualitative hydration and dehydration rates in line with changes in an individual’s urine specific gravity and body mass. The real-time changes in galvanic coupled intrabody signal attenuation can be integrated into wearable electronic devices to evaluate body fluid levels on a particular area of interest and can aid diagnosis and treatment of fluid disorders such as lymphoedema.

  9. Effects of Welding Parameters on Strength and Corrosion Behavior of Dissimilar Galvanized Q&P and TRIP Spot Welds

    Directory of Open Access Journals (Sweden)

    Pasquale Russo Spena

    2017-12-01

    Full Text Available This study investigates the effects of the main welding parameters on mechanical strength and corrosion behavior of galvanized quenching and partitioning and transformation induced plasticity spot welds, which are proposed to assemble advanced structural car elements for the automotive industry. Steel sheets have been welded with different current, clamping force, and welding time settings. The quality of the spot welds has been assessed through lap-shear and salt spray corrosion tests, also evaluating the effects of metal expulsion on strength and corrosion resistance of the joints. An energy dispersive spectrometry elemental mapping has been used to assess the damage of the galvanized zinc coating and the nature of the corrosive products. Welding current and time have the strongest influence on the shear strength of the spot welds, whereas clamping force is of minor importance. However, clamping force has the primary effect on avoiding expulsion of molten metal from the nugget during the joining process. Furthermore, clamping force has a beneficial influence on the corrosion resistance because it mainly hinders the permeation of the corrosive environment towards the spot welds. Although the welded samples can exhibit high shear strength also when a metal expulsion occurs, this phenomenon should be avoided because it enhances the damage and vaporization of the protective zinc coating.

  10. Galvanic manufacturing in the cities of Russia: potential source of ambient nanoparticles.

    Directory of Open Access Journals (Sweden)

    Kirill S Golokhvast

    Full Text Available Galvanic manufacturing is widely employed and can be found in nearly every average city in Russia. The release and accumulation of different metals (Me, depending on the technology used can be found in the vicinities of galvanic plants. Under the environmental protection act in Russia, the regulations for galvanic manufacturing do not include the regulations and safety standards for ambient ultrafine and nanosized particulate matter (PM. To assess whether Me nanoparticles (NP are among environmental pollutants caused by galvanic manufacturing, the level of Me NP were tested in urban snow samples collected around galvanic enterprises in two cities. Employing transmission electronic microscopy, energy-dispersive X-ray spectroscopy, and a laser diffraction particle size analyzer, we found that the size distribution of tested Me NP was within 10-120 nm range. This is the first study to report that Me NP of Fe, Cr, Pb, Al, Ni, Cu, and Zn were detected around galvanic shop settings.

  11. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 1: formative years, naturphilosophie, and galvanism.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    During the 1790s, Alexander von Humboldt (1769-1859), who showed an early interest in many facets of natural philosophy and natural history, delved into the controversial subject of galvanism and animal electricity, hoping to shed light on the basic nature of the nerve force. He was motivated by his broad worldview, the experiments of Luigi Galvani, who favored animal electricity in more than a few specialized fishes, and the thinking of Alessandro Volta, who accepted specialized fish electricity but was not willing to generalize to other animals, thinking Galvani's frog experiments flawed by his use of metals. Differing from many German Naturphilosophen, who shunned "violent" experiments, the newest instruments, and detailed measurement, Humboldt conducted thousands of galvanic experiments on animals and animal parts, as well as many on his own body, some of which caused him great pain. He interpreted his results as supporting some but not all of the claims made by both Galvani and Volta. Notably, because of certain negative findings and phenomenological differences, he remained skeptical about the intrinsic animal force being qualitatively identical to true electricity. Hence, he referred to a "galvanic force," not animal electricity, in his letters and publications, a theoretical position he would abandon with Volta's help early in the new century.

  12. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position

    OpenAIRE

    Hong Ju; Yuan-Feng Yang; Yun-Fei Liu; Shu-Fa Liu; Jin-Zhuo Duan; Yan Li

    2018-01-01

    The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2), titanium (TA2), and 316L stainless steel (316L SS). These electrodes were used with artificial seawater at different temperatures. The potential and current–density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled...

  13. In Situ Apparatus to Study Gas-Metal Reactions and Wettability at High Temperatures for Hot-Dip Galvanizing Applications

    Science.gov (United States)

    Koltsov, A.; Cornu, M.-J.; Scheid, J.

    2018-02-01

    The understanding of gas-metal reactions and related surface wettability at high temperatures is often limited due to the lack of in situ surface characterization. Ex situ transfers at low temperature between annealing furnace, wettability device, and analytical tools induce noticeable changes of surface composition distinct from the reality of the phenomena.Therefore, a high temperature wettability device was designed in order to allow in situ sample surface characterization by x-rays photoelectron spectroscopy after gas/metal and liquid metal/solid metal surface reactions. Such airless characterization rules out any contamination and oxidation of surfaces and reveals their real composition after heat treatment and chemical reaction. The device consists of two connected reactors, respectively, dedicated to annealing treatments and wettability measurements. Heat treatments are performed in an infrared lamp furnace in a well-controlled atmosphere conditions designed to reproduce gas-metal reactions occurring during the industrial recrystallization annealing of steels. Wetting experiments are carried out in dispensed drop configuration with the precise control of the deposited droplets kinetic energies. The spreading of drops is followed by a high-speed CCD video camera at 500-2000 frames/s in order to reach information at very low contact time. First trials have started to simulate phenomena occurring during recrystallization annealing and hot-dip galvanizing on polished pure Fe and FeAl8 wt.% samples. The results demonstrate real surface chemistry of steel samples after annealing when they are put in contact with liquid zinc alloy bath during hot-dip galvanizing. The wetting results are compared to literature data and coupled with the characterization of interfacial layers by FEG-Auger. It is fair to conclude that the results show the real interest of such in situ experimental setup for interfacial chemistry studies.

  14. OPTIMIZATION OF SURFACE ROUGHNESS OF AISI 304 AUSTENITIC STAINLESS STEEL IN DRY TURNING OPERATION USING TAGUCHI DESIGN METHOD

    Directory of Open Access Journals (Sweden)

    D. PHILIP SELVARAJ

    2010-09-01

    Full Text Available The present work is concentrated with the dry turning of AISI 304 Austenitic Stainless Steel (ASS. This paper presents the influence of cutting parameters like cutting speed, feed rate and depth of cut on the surface roughness of austenitic stainless steel during dry turning. A plan of experiments based on Taguchi’s technique has been used to acquire the data. An orthogonal array, the signal to noise (S/N ratio and the analysis of variance (ANOVA are employed to investigate the cutting characteristics of AISI 304 austenitic stainless steel bars using TiC and TiCN coated tungsten carbide cutting tool. Finally the confirmation tests that have been carried out to compare the predicted values with the experimental values confirm its effectiveness in the analysis of surface roughness.

  15. Drying Effects on Corrosion Properties of Cr(VI) and Cr(III) Treated Electrogalvanized Steel

    NARCIS (Netherlands)

    Zhang, X.; Van den Bos, C.; Sloof, W.G.; Hovestad, A.; Terryn, H.; De Wit, J.H.W.

    2006-01-01

    Drying effects on corrosion performance of Cr(VI)- and Cr(III)-treated electro-galvanized steel have been studied in NaCl solution using potentiodynamic measurements and electrochemical impedance spectroscopy (EIS). The Cr(VI) and the Cr(III) treated specimens were dried at three different

  16. Residual stress measurements on steel using neutron high resolution powder diffractometer (HRPD)

    International Nuclear Information System (INIS)

    Inawati Tanto

    1996-01-01

    Stress analysis by neutron diffraction is based on the determination of lattice strains by precise measurements of the d spacing. Residual stress measurements were made on 0.7 mm of a rolled thin steel and on 1.65 mm of a galvanized flat steel. The neutron measurements in the vertical and horizontal directions were made in transmission and reflection geometry using HRPD on the Hifar Reactor at Lucas Heights, Australia. It can be concluded that the stress arise on the weld section of the galvanized flat steel was compression. On rolled thin steel stresses were measured at the rolled and unrolled section. Datas collected were not consistent with the expectations for example the horizontal rolled measurement was expected to show compressive residual stress, however the opposite was observed. (author), 4 refs, 2 tabs, 1 figs

  17. Experience with the manufacture of 13 MnNiMo 5 4 steel for hot-operating pressure vessels

    International Nuclear Information System (INIS)

    Ackermann, W.; Reumont, G.A. von

    1977-01-01

    The composition of grade 13 MnNiMo 5 4 steel in relation to material and manufacturing characteristics has been optimised within the permissible margins. The tendency of stress relief cracking to occur has been determined with a series of relaxation samples in accordance with Murray. The chemical composition has no influence on the relaxation behaviour within the scope of range of analyses. The lives measured indicate that the steel is insensitive to stress relief cracking. The mechanical characteristics are in no way impaired by the heat shaping of the metal plate. On the contrary, an increase in the toughness characteristics is often observed because of double heat treatment. (orig.) [de

  18. Corrosion behaviour of the welded steel sheets used in automotive industry

    OpenAIRE

    D. Katundi; A. Tosun-Bayraktar; E. Bayraktar; D. Toueix

    2010-01-01

    Purpose: of this paper is to characterise the corrosion resistance in the steel sheets (Hot dip galvanizing of steel sheets) used in automotive industry. In fact, corrosion of automotive components by road salt is a widely known problem. The different parts under the car body and the interior surface of body panels suffer easily from the corrosive products deposited on roads and used mainly to melt snow. A comparison in a chemical investigation of the corrosion rate for base metals (without w...

  19. Optimal design of galvanic corrosion protection systems for offshore wind turbine support structures

    DEFF Research Database (Denmark)

    Sarhadi, Ali; Abrahamsen, Asger Bech; Stolpe, Mathias

    2018-01-01

    The current work addresses a mass/cost optimization procedure for galvanic anode cathodic protection (GACP) systems based on both cathodic protection (CP) standards and numerical simulation. An approach is developed for optimizing the number and dimensions of the galvanic anodes, distributing the...

  20. Thermal ageing of steels; from expertise and understanding of the ageing mechanisms to a maintenance strategy for operating nuclear power plants

    International Nuclear Information System (INIS)

    Bezdikian, G.; Ould, P.

    2004-01-01

    Some parts of reactor coolant circuit on Nuclear PWR power plants, elbows on primary circuit, are made in cast duplex stainless steel material. It is now identify that the mechanical characteristic of this material should be decrease under thermal ageing mainly after a long time in operation in at reactor coolant circuit temperature conditions. The sensitiveness to the thermal ageing of these components is in relation with chemical composition and the ferrite content, especially the grade of Chromium equivalent (Ceq %Cr + %Si + %Mo). In the context of justification to maintain in operation on the plants these cat duplex components, an important programme of expertises was carried out on cast elbows after removing on the plants during the Steam Generators replacements (SGR). Several expertises, performed in the objective to understand the thermal ageing phenomenon and mechanism on cast components in service on plants, were permit to validate the prediction formulas established from a large database and programme in laboratories. The expertises were based on a lot of metallurgical, mechanical and chemical characteristics of components in operation Small Angle Neutrons Scattering (SANS), Thermal Electric Power (TEP), micro hardness and toughness measurement on small specimens from boat sample (CT10-5) The expertise carried out on one SG inlet elbows from DAMPIERRE, removed a during SGR after 100000 h in operation is shown, the toughness values are very high compared to the prediction formulas. The TEP measurements performed on the specimen cut off on two elbows and the ingots of the same material aged in laboratory in furnace, are very coherent; it is confirmed that this methodology is a good indicator to follow the ageing characteristic of material. The results of expertises on aged material are a mean of validation of the methodology applied on the file of demonstration of maintaining in operation of cast duplex stainless steel sensitive to thermal ageing. So the

  1. Corrosion damage examples and brittleness affecting containing carbon steel materials of the PWR type reactors

    International Nuclear Information System (INIS)

    Millet, L.; Dordonat, M.; Guttmann, D.; Calle, P.

    1993-01-01

    Intercrystalline corrosion has been observed in carbon steel heat exchanger tubes. Waterproof turbine boxes composed of graphite rings and carbon steel, some coated with a KANIGEN chemical nickel, may develop a galvanic coupling corrosion between the graphite rings and the carbon steel body. In a steam impulsion pipe circuit, fatigue corrosion and stress corrosion cracking may appear. Brittleness of carbon steel is linked to an anomalous composition with an excess content of phosphorus and nitrogen. Lamellar wrenchings are observed on steam pipes connection. 5 refs., 3 figs

  2. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

    Cruz V, J. P.; Vite T, J.; Castillo S, M.; Vite T, M.

    2009-01-01

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  3. Gold recovery from organic solvents using galvanic stripping

    Energy Technology Data Exchange (ETDEWEB)

    Flores, C.; O`Keefe, T.J. [Univ. of Missouri, Rolla, MO (United States). Dept. of Metallurgical Engineering

    1995-08-01

    A novel process using solid metals for the direct reduction of more noble metal ions from solvent extraction organics has been developed. Base metals recovery has been the principal focus of investigations to date but feasibility tests have now also been made on galvanically stripping selected precious metals. In this study gold (III) was loaded from an aqueous HAuCl{sub 4}{center_dot}3H{sub 2}O solution into a mixed organic 40 vol.% TBP, 10 vol.% D2EHPA in kerosene. The direct precipitation of metallic gold from the loaded organic phase using zinc powder and iron, aluminum and copper slabs at 70 C was successfully demonstrated. The gold reduction rates were relatively fast even though the conductivity of the organic solutions is very low. The reaction rates were studied as a function of the variables zinc particulate size, oxygen and nitrogen atmosphere, water content in the organic phase, organic ratios and temperature. The gold morphology was usually powdery or dendritic in nature but continuous films were obtained in some instances. Activation energies were calculated and possible reaction mechanisms are discussed. In general, the results obtained were very promising and showed that gold can be successfully cemented from selected organic solvents by galvanic stripping using less noble solid metal reductants.

  4. Assessment of exposure pathways connected with construction and operation of concrete bridge reinforced with very low level radioactive steel

    International Nuclear Information System (INIS)

    Panik, M.; Necas, V.

    2012-01-01

    Large amount of low level radioactive material arises during decommissioning of nuclear power plants. Material mostly comprises metal scrap and concrete ruble. Paper deals with recycling and reuse of metal scrap and its utilization as part of reinforcement of concrete bridges under the conditional release concept. Radiation exposure originating in very low level reinforcement steel consists of several exposure pathways. Short-term radiation impact is represented mostly by external exposure pathway and it is relevant to the construction workers and users of the bridge. Long-term radiation impacts on inhabitants living near finished bridge and it is divided into inhalation and ingestion of radionuclides-internal exposure pathways. Radiation impact caused by utilization of very low level radioactive waste was calculated using simulation software VISIPLAN 3D ALARA and GOLDSIM. Results of calculations provide fair summary of possibilities of utilization of conditionally released steel as reinforcement of concrete bridges. (Authors)

  5. Evaluation of external exposure during building and operation of concrete bridges constructions that reuse the conditionally released steels - 59120

    International Nuclear Information System (INIS)

    Panik, Michal; Necas, Vladimir

    2012-01-01

    This paper presents ongoing results of the project presented at ICEM'10 [1] related to the topics of reusing the conditionally released materials from decommissioning. The subject of the reuse of conditionally released materials in this case is modeling of bridge constructions which reuse the conditionally released steel in the form of reinforcement bars for the concrete bridges. A general approach for the project was presented at ICEM'10. The activities of the project continue in evaluating the individual effective doses from the external exposure based on reused conditionally released steels separately for public and for professionals (the internal exposure will be evaluated in next stages of the project). Evaluated scenarios are related to critical groups of professionals constructing the bridges (worker's scenarios). The computer code VISIPLAN 3D ALARA 4.0 planning tool was used for the calculation of the individual effective dose for professionals. Various limits of the annual individual effective dose are used for the evaluation of calculation results. The aim of the ongoing modeling is to develop a set of data of maximal radioactivity concentration for individual radionuclides in the conditionally released steel used in the bridges model constructions in order not to exceed the limits for the individual effective dose. (authors)

  6. Comparative life cycle cost assessment of painted and hot-dip galvanized bridges.

    Science.gov (United States)

    Rossi, B; Marquart, S; Rossi, G

    2017-07-15

    The study addresses the life cycle cost assessment (LCCA) of steel bridges, focusing on the maintenance activities and the maintenance scenario. Firstly, the unit costs of maintenance activities and their durability (i.e. the time between two activities) are evaluated. Pragmatic data are provided for the environment category C4 and for three activities: Patch Up, Overcoating and Remove & Replace. A comparative LCCA for a typical hypothetic steel girder bridge is carried out, either painted or hot-dip galvanized (HDG), in the environmental class C4. The LCC versus the cumulated life is provided for both options. The initial cost of the steel unpainted option is only 50.3% of the HDG option. It is shown that after 'Overcoating' occurring at 18.5 years, the total Net Present Value (NPV) of the painted option surpasses that of the HDG option. A sensitivity analysis of the NPV to the cost and service life parameters, the escalation and discount rates is then performed. The discount and escalation rates, considerably influences the total LCC, following a non-linear trend. The total LCC decreases with the discount rate increasing and, conversely, increases with the escalation rate increasing. Secondly, the influence of the maintenance scenario on the total LCC is assessed based on a probabilistic approach. A permutation of the three independent maintenance activities assumed to occur six times over the life of the bridge is considered and a probability of occurrence is associated to each unique scenario. The most probable scenarios are then classified according to their NPV or achieved service life. This approach leads to the definition of a cost-effective maintenance scenario i.e. the scenario, within all the considered permutations, that has the minimum LCC in a range of lifespan. Besides, the probabilistic analysis also shows that, whatever the scenario, the return on investment period ranges between 18.5 years and 24.2 years. After that period, the HDG option becomes

  7. Fatigue of coated and laser hardened steels

    International Nuclear Information System (INIS)

    La Cruz, P. de.

    1990-01-01

    In the present work the effect of ion nitriding, laser hardening and hot dip galvanizing upon the fatigue limit and notch sensitivity of a B-Mn Swedish steel SS 2131 have been investigated. The fatigue tests were performed in plane reverse bending fatigue (R=1). The quenched and tempered condition was taken as the reference condition. The microstructure, microhardness, fracture surface and coating appearance of the fatigue surface treated specimens were studied. Residual stress and retained austenite measurements were also carried out. It was found that ion nitriding improves the fatigue limit by 53 % for smooth specimens and by 115 % for notched specimens. Laser hardening improves the fatigue limit by 18 % and 56 % for smooth and notched specimen respectively. Hot dip galvanizing gives a slight deterioration of the fatigue limit (9 % and 10 % for smooth and notched specimen respectively). Ion nitriding and laser hardening decrease the value of the notch sensitivity factor q by 78 % and 65 % respectively. Hot dip galvanizing does not modify it. A simple schematic model based on a residual stress distribution, has been used to explain the different effects. It seems that the presence of the higher compressive residual stresses and the higher uniformity of the microstructure may be the causes of the better fatigue performance of ion nitrided specimens. (119 refs.) (author)

  8. Development for the production of low phosphorus steel in operations at Arcelor Mittal Tubarão

    Directory of Open Access Journals (Sweden)

    Luiz-Corrêa, W.

    2013-04-01

    Full Text Available The growing demand to produce steel with lower phosphorus (P content happens in tandem with the increase in the content of this element in the ores used in the production of pig iron, leading to a constant evolution in the process of steel dephosphorization in BOF converters. Arcelor Mittal Tubarão (AMT, located in the municipality of Serra, Brazil, currently produces 5 million t of steel, but has an installed capacity of 7.5 million. This work aims at showing the development carried out in the dephosphorization of silicon-aluminium killed steel produced in the Arcelor Mittal Tubarão converters. The analysis of process variables such as flux addition, oxygen lance position and temperature at the end of blow are based on classical phosphorus partition models. The results compare phosphorus values in liquid steel before and after modifications in the variables and the refractory wear caused by the new procedures applied to AMT steelmaking converters.Con la creciente demanda de aceros cada vez más bajos en fósforo (P, junto con el constante aumento en el contenido de este elemento en el mineral utilizado para producir arrabio, es necesario un proceso en constante evolución para la eliminación de fósforo del acero en los convertidores BOF. Este artículo tiene como objetivo mostrar el desarrollo para reducir el nivel de fósforo en el acero desoxidado con aluminio y silicio producido en los convertidores de Arcelor Mittal Tubarão (AMT, empresa ubicada en el municipio de Serra, Brasil. Este complejo produce 5 millones de toneladas pero tiene una capacidad instalada de 7,5 millones. El análisis de las variables del proceso tales como adición de fundentes, temperatura y el patrón de soplado, se basó en los modelos clásicos de la partición de fósforo. Los resultados presentados comparan los valores de fósforo obtenidos en el acero líquido antes y después de los cambios realizados, y analiza el desgaste de refractarios en los

  9. Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation

    Directory of Open Access Journals (Sweden)

    Stefan Kammermeier

    2017-11-01

    Full Text Available IntroductionHuman multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation.Methods14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording.ResultsVestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects (“grand average” bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study.ConclusionGalvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level.SignificanceDifferential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

  10. Impact of Music on College Students: Analysis of Galvanic Skin Responses

    Directory of Open Access Journals (Sweden)

    Atefeh GOSHVARPOUR

    2014-12-01

    Full Text Available Purpose: The impact of music on the human body is an important trend in music research. Different kinds of music have direct and indirect effects on physiological functions and parameters in normal and pathological conditions. Among various physiological measurements, the galvanic skin response is a noninvasive, useful, simple and reproducible method of capturing the autonomic nerve response. The aim of this study is to evaluate the effect of Persian music on galvanic skin response. Basic methods: Galvanic skin response signals of 25 college students (10 women and 15 men were collected. Mean, amplitude, rise time and Lyapunov exponents of the signals were calculated. Main results: The results show that not only the galvanic skin response amplitude is higher in men subjects during rest, but it also increased to the higher values during music than that of women. In addition, the fluctuations of it increased during music in men group; while it decreased in women group. The positive values of Lyapunov exponents suggest that all galvanic skin responses have low dimensional chaos. In addition, the complexity of galvanic skin responses is decreased during music. Conclusions: Our study has shown that the same music protocol has different reflections on the galvanic skin response of women and men. Furthermore, the proposed method may serve as a quantitative measure for emotional states such as listening to the music.

  11. Growth and galvanic replacement of silver nanocubes in organic media

    Science.gov (United States)

    Polavarapu, Lakshminarayana; Liz-Marzán, Luis M.

    2013-05-01

    Although metal nanoparticles with various shapes can be prepared in polar organic solvents, little has been advanced toward the shape-controlled synthesis in non-polar solvents. We report a simple method for the synthesis of nearly monodisperse single crystalline silver nanocubes in a non-polar solvent (1,2-dichlorobenzene) by using oleylamine as both a reducing and capping agent. Mechanistic studies based on the time evolution of Ag nanoparticles revealed that multiply twinned nanocrystals form at the beginning of the reaction, which are gradually transformed into single crystalline Ag nanocubes by oxidative etching. Control experiments showed that the solvent plays an important role in the formation of such single crystalline Ag nanocubes. The effects of reaction temperature, oleylamine concentration, solvent, and the nature of the silver ion precursor on the morphology and monodispersity of the nanoparticles were systematically investigated. Additionally, the galvanic replacement reaction with HAuCl4 in an organic medium was implemented to prepare hydrophobic hollow Au-Ag nanocages with tunable localized surface plasmon resonances.Although metal nanoparticles with various shapes can be prepared in polar organic solvents, little has been advanced toward the shape-controlled synthesis in non-polar solvents. We report a simple method for the synthesis of nearly monodisperse single crystalline silver nanocubes in a non-polar solvent (1,2-dichlorobenzene) by using oleylamine as both a reducing and capping agent. Mechanistic studies based on the time evolution of Ag nanoparticles revealed that multiply twinned nanocrystals form at the beginning of the reaction, which are gradually transformed into single crystalline Ag nanocubes by oxidative etching. Control experiments showed that the solvent plays an important role in the formation of such single crystalline Ag nanocubes. The effects of reaction temperature, oleylamine concentration, solvent, and the nature of the

  12. Theory of the Spin Galvanic Effect at Oxide Interfaces

    Science.gov (United States)

    Seibold, Götz; Caprara, Sergio; Grilli, Marco; Raimondi, Roberto

    2017-12-01

    The spin galvanic effect (SGE) describes the conversion of a nonequilibrium spin polarization into a transverse charge current. Recent experiments have demonstrated a large conversion efficiency for the two-dimensional electron gas formed at the interface between two insulating oxides, LaAlO3 and SrTiO3 . Here, we analyze the SGE for oxide interfaces within a three-band model for the Ti t2 g orbitals which displays an interesting variety of effective spin-orbit couplings in the individual bands that contribute differently to the spin-charge conversion. Our analytical approach is supplemented by a numerical treatment where we also investigate the influence of disorder and temperature, which turns out to be crucial to providing an appropriate description of the experimental data.

  13. Synthesis of Supported Bimetal Catalysts using Galvanic Deposition Method.

    Science.gov (United States)

    Mahara, Yuji; Ohyama, Junya; Sawabe, Kyoichi; Satsuma, Atsushi

    2018-02-22

    Supported bimetallic catalysts have been studied because of their enhanced catalytic properties due to metal-metal interactions compared with monometallic catalysts. We focused on galvanic deposition (GD) as a bimetallization method, which achieves well-defined metal-metal interfaces by exchanging heterogeneous metals with different ionisation tendencies. We have developed Ni@Ag/SiO 2 catalysts for CO oxidation, Co@Ru/Al 2 O 3 catalysts for automotive three-way reactions and Pd-Co/Al 2 O 3 catalysts for methane combustion by using the GD method. In all cases, the catalysts prepared by the GD method showed higher catalytic activity than the corresponding monometallic and bimetallic catalysts prepared by the conventional co-impregnation method. The GD method provides contact between noble and base metals to improve the electronic state, surface structure and reducibility of noble metals. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Studies on inhibition of galvanic corrosion of lead based solders

    International Nuclear Information System (INIS)

    Perumareddi, R.; Sastri, V.S.; Elboujdaini, M.

    1999-01-01

    Exposure of Pb/Sn solder embedded in copper plates releases Pb into tap water and well water in excess of permissible level of 10 μg/L. Release of Pb has been inhibited by adding 40 ppm of silicate or 20 ppm of silicate and 20 ppm of phosphate to tap water and well water. XPS, electron microprobe and EDAX analysis of the solder surfaces show the surfaces deposits to be copper silicate and copper silicate and calcium carbonate on Pb/Sn surfaces exposed to tap and well water respectively containing silicate. The release of Pb can be explained satisfactorily on the basis of a scheme of reactions due to galvanic corrosion. (author)

  15. Design of a fixed-bed ion-exchange process for the treatment of rinse waters generated in the galvanization process using Laminaria hyperborea as natural cation exchanger.

    Science.gov (United States)

    Mazur, Luciana P; Pozdniakova, Tatiana A; Mayer, Diego A; Boaventura, Rui A R; Vilar, Vítor J P

    2016-03-01

    In this study, the removal of zinc from galvanization wastewaters was performed in a fixed bed column packed with brown macro-algae Laminaria hyperborea, acting as a natural cation exchanger (resin). The rinse wastewater presents a zinc concentration between 9 and 22 mg/L, a high concentration of light metals (mainly Na and Ca), a high conductivity (0.5-1.5 mS/cm) and a low organic content (DOC = 7-15 mg C/L). The zinc speciation diagram showed that approximately 80% of zinc is in the form of Zn(2+) and ≅20% as ZnSO4, considering the effluent matrix. From all operational conditions tested for zinc uptake (17 treatment of 2.4 m(3)/day of galvanization wastewater, resulting in an estimated reactants cost of 2.44 €/m(3). Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. The mechanisms underlying corrosion product formation and deposition in nuclear power plant circuits through the action of galvanic and thermal electromotive forces

    International Nuclear Information System (INIS)

    Brusakov, V.P.; Sedov, V.M.; Khitrov, Yu.A.; Brusov, K.N.; Razmashkin, N.V.; Versin, V.V.; Rybalchenko, I.L.

    1983-01-01

    From a theoretical standpoint, the processes of formation of corrosion products in nuclear power plant circuits, deposition of corrosion products on the circuit surfaces, formation of an equilibrium concentration of corrosion products in the coolant, and distribution of radionuclides resulting from corrosion in different parts of the circuit are considered. It is shown that the main driving forces for the mass-transfer processes in the circuits are the thermal and galvanic electromotive forces (EMF) of the microcouples. On the basis of the theoretical concepts developed the authors have obtained analytical dependences for calculating the individual stages of the process of corrosion product transfer in the circuits. The mechanisms underlying the processes which occur as a result of thermal and galvanic EMFs are considered, together with the factors influencing these processes. The results of verification of the dependences by computational methods are given and they are compared with operational data from nuclear and conventional thermal power plants and with experimental data. (author)

  17. Effect of Mg on the Microstructure and Corrosion Resistance of the Continuously Hot-Dip Galvanizing Zn-Mg Coating

    Science.gov (United States)

    Dong, Anping; Li, Baoping; Lu, Yanling; Zhu, Guoliang; Xing, Hui; Shu, Da; Sun, Baode; Wang, Jun

    2017-01-01

    The microstructure of continuously hot-dip galvanizing Zn-Mg coating was investigated in order to obtain the mechanism of the effects of Mg on the corrosion resistance. In this paper, the vertical section of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner was calculated. The results indicates that the phase composition of the Zn-0.20 wt % Al-Mg ternary phase diagram near the Al-low corner is the same as Zn-Mg binary phase diagram, suggesting Al in the Zn-Mg (ZM) coatings mainly concentrates on the interfacial layer between the coating and steel substrate. The microstructure of continuously hot-dip galvanizing ZM coatings with 0.20 wt % Al containing 1.0–3.0 wt % Mg was investigated using tunneling electron microscopy (TEM). The morphology of Zn in the coating changes from bulk to strip and finally to mesh-like, and the MgZn2 changes from rod-like to mesh-like with the Mg content increasing. Al in the ZM coatings mainly segregates at the Fe2Al5 inhibition layer and the Mg added to the Zn bath makes this inhibition layer thinner and uneven. Compared to GI coating, the time of the first red rust appears increases by more than two-fold and expansion rate of red rust reduces by more than four-fold in terms of salt spray experiment. The ZM coating containing 2.0 wt % Mg has the best corrosion resistance. The enhanced corrosion resistance of ZM coatings mainly depends on different corrosion products. PMID:28829393

  18. Review on experience in operation of steels for use as fast reactor fuel element cladding and wrappers

    International Nuclear Information System (INIS)

    Weisz, Michel.

    1978-01-01

    The informations on the behavior of steels which can be gathered from routine destructive or non-destructive examination of fast reactor cans and wrapper tubes are presented. The relative merits of swelling measurements made on specimens or on real cans are compared. The diametral deformations of all the cans of a bundle and the immersion density measurements on industrial fabrication of wrapper tubes are discussed. The swelling temperature relationships and the double peak swelling of SA316 in relation with microstructural evolution are studied. Irradiation creep is also investigated, particularly the bulging of the wrapper tubes allowing to derive mean creep rate measurements for the high dose region [fr

  19. Replacement of steel cable with synthetic rope in mountain logging operations in Castanea sativa Mill. coppice stands

    Directory of Open Access Journals (Sweden)

    Elena Canga

    2014-12-01

    Full Text Available Aim of the study: The objective of this study was to evaluate skidding from stump area to roadside with a tracked skidder (Caterpillar 3DG XL using two different types of cable (steel or synthetic.Area of study: NW of Spain.Material and methods: A time study was performed to calculate productivity for the two types of cable and two regression models were fitted to predict the productive and cycle time of the tracked skidder.Research highlights: An increase of 12.53% in productivity (m3/SMH and improvements in working conditions using synthetic rope were found.Keywords: Chestnut; synthetic rope; time study; tracked skidder.

  20. Electrochemical Determination of Hydrogen Entry to HSLA Steel during Pickling

    Directory of Open Access Journals (Sweden)

    Jari Aromaa

    2018-01-01

    Full Text Available Pickling with hydrochloric acid is a standard method to clean steel surfaces before hot-dip galvanizing. When normal low strength steels are pickled, hydrogen formed in pickling reactions does not have any significant harmful effect on the mechanical properties of steel. However, in pickling of steels with higher strength, the penetration of hydrogen into the steel may cause severe damages. The effect of pickling of high-strength low-alloy (HSLA steels was investigated using a cell construction based on the Devanathan-Stachurski method with modified anodic surface treatment and hydrogen production using acid. The penetration and the permeability of hydrogen were measured using an electrochemical cell with hydrochloric acid on the one side of the steel sample and a solution of NaOH on the other side. No protective coating, for example, palladium on the anodic side of the sample, is needed. The penetration rate of hydrogen into the steel and exit rate from the steel were lower for higher strength steel.

  1. The corrosion protection of AISI(TM) 1010 steel by organic and inorganic zinc-rich primers

    Science.gov (United States)

    Danford, M. D.; Mendrek, M. J.

    1995-01-01

    The behavior of zinc-rich primer-coated AISI 1010 steel in 3.5-percent Na-Cl was investigated using electrochemical techniques. The alternating current (ac) method of electrochemical impedance spectroscopy (EIS), in the frequency range of 0.001 to 40,000 Hz, and the direct current (dc) method of polarization resistance (PR), were used to evaluate the characteristics of an organic, epoxy zinc-rich primer and an inorganic, ethyl silicate zinc-rich primer. A dc electromechanical galvanic corrosion test was also used to determine the corrosion current of each zinc-rich primer anode coupled to a 1010 steel cathode. Duration of the EIS/PR and galvanic testing was 21 days and 24 h, respectively. The galvanic test results demonstrated a very high current between the steel cathode and both zinc-rich primer anodes (38.8 and 135.2 microns A/sq cm for the organic and inorganic primers, respectively). The results of corrosion rate determinations demonstrated a much higher corrosion rate of the zinc in the inorganic primer than in the organic primer, due primarily to the higher porosity in the former. EIS equivalent circuit parameters confirmed this conclusion. Based on this investigation, the inorganic zinc-rich primer appears to provide superior galvanic protection and is recommended for additional study for application on solid rocket booster steel hardware.

  2. Influence of stainless steel Internals on Corrosion of tower wall materials

    Science.gov (United States)

    Chen, Bing; Ren, Ke

    2017-12-01

    In view of the galvanic corrosion of the tower wall material in the tower of a refinery atmospheric vacuum distillation unit, the electrochemical behavior of Q345R steel, stainless steel (201, 304 cold-rolled plate, 304 hot rolled plate and 316L) in 3.5%NaCl solution was studied by electrochemical method. The results show that the corrosion potential of Q345R is much lower than that of stainless steel, and the corrosion rate of Q345R is higher than that of stainless steel. As the anode is etched as the anode corrosion, the anode polarizability of stainless steel shows strong polarization ability, which is anodic polarization control, and Q345R is anode Active polarization control; Q345R / 201 galvanic pair may be the most serious corrosion, and Q345R/316L galvanic couple may be relatively slight. Therefore, in the actual production of tower equipment, material design or tower to upgrade the replacement, it are recommended to use the preferred anode and cathode potential difference with the use of materials.

  3. AA6082 to DX56-Steel Laser Brazing: Process Parameter-Intermetallic Formation Correlation

    Science.gov (United States)

    Narsimhachary, D.; Pal, S.; Shariff, S. M.; Padmanabham, G.; Basu, A.

    2017-09-01

    In the present study, laser-brazed AA6082 to DX56-galvanized steel joints were investigated to understand the influence of process parameters on joint strength in terms of intermetallic layer formation. 1.5-mm-thick sheet of aluminum alloy (AA6082-T6) and galvanized steel (DX56) sheet of 0.7 mm thickness were laser-brazed with 1.5-mm-diameter Al-12% Si solid filler wire. During laser brazing, laser power (4.6 kW) and wire feed rate (3.4 m/min) were kept constant with a varying laser scan speed of 3.5, 3, 2.5, 2, 1.5, and 1 m/min. Microstructure of brazed joint reveals epitaxial growth at the aluminum side and intermetallic layer formation at steel interface. Intermetallic layer formation was confirmed by EDS analysis and XRD study. Hardness profile showed hardness drop in filler region, and failure during tensile testing was initiated through the filler region near the steel interface. As per both experimental study and numerical analysis, it was observed that intermetallic layer thickness decreases with increasing brazing speed. Zn vaporization from galvanized steel interface also affected the joint strength. It was found that high laser scan speed or faster cooling rate can be chosen for suppressing intermetallic layer formation or at least decreasing the layer thickness which results in improved mechanical properties.

  4. Corrosion of Ultrasonic spot Welded Joints of Magnesium to Steel

    Science.gov (United States)

    Pan, Tsung-Yu; Santella, Michael L.

    Mixed-metal joining, especially between magnesium and steel, is one of the critical technologies in achieving light-weighting vehicle body construction. However, galvanic corrosion between mixed metal joints is inevitable but not well quantified. In this study, 1.6 mm thick Mg AZ31B-H24 was joined to 0.8 mm thick hot-dipped galvanized (HDG) mild steel by ultrasonic spot welding in lap-shear configuration. No specific corrosion protection was applied in order to study worst-case conditions for corrosion behavior. The approach used an automotive cyclic corrosion test — Ford Arizona Proving Ground Equivalent Corrosion Cycle (APGE), which includes cycles of dipping in a salt bath, air drying, then holding in constant humidity environment. Lap-shear strength of the joints decreased linearly with the exposure cycles. All the joints were either taken out of test cycle for mechanical test or they separated within the humidity chamber before 25th cycle. X-ray diffraction analysis confirmed the formation of Mg(OH)2 deposit in the crevice between the AZ31 and steel sheets and on the surface of the AZ31. The deposit grew thicker with cycles with exerting enough force to deform the AZ31 and HDG steel and causing a gradual opening of joints. The corrosion of the AZ31 was localized and nonuniform. The most severe corrosion occurred not at the intersection of AZ31 and the steel but rather 15-20 mm away from the spot welds.

  5. Surface composition of the Be limiters and the stainless-steel torus wall after operation in UNITOR

    International Nuclear Information System (INIS)

    Martinelli, A.P.; Behrisch, R.; Hammer, H.; Hackmann, J.

    1986-12-01

    The surfaces of two Be limiters and of a test sample from the stainless-steel torus wall used in UNITOR were analyzed by RBS, PIXE, AES, and SEM/EIXE. The main foreign atoms found on the limiters are 0 (2x10 17 to 2x10 18 /cm 2 ), Fe, Ni, Cr and Sn (2x10 15 to 2x10 16 /cm 2 ). There are no large differences in the foreign atom coverage on the different surface areas of the limiters. Generally, the front surfaces of the limiters show slightly lower coverage than the sides. On limiter 2, the Sn coverage is about a factor of 4 larger than on limiter 1, indicating that the Sn source was close to this limiter. The stainless-steel test sample from the torus wall shows islands of BeO, which can be attributed to splashes or droplets eroded from the limiters during disruptions. Major erosion of the limiters occurrd only during the first 100 shots, when many discharges were terminated by disruptions. Redeposited wall material is found on the wall sample which partly covers the BeO deposits. The surface modifications of limiters and wall samples were discussed by taking into account the particle fluxes from and to the walls and limiters. (orig.)

  6. Crack growth behaviour of low-alloy steels for pressure boundary components under transient light water reactor operating conditions - CASTOC, Part II: WWER conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ernestova, M.; Zamboch, M. [Nuclear Research Institute, NRI, Rez (Czech Republic); Devrient, B.; Roth, A. [Framatome ANP GmbH, Erlangen (Germany); Ehrnsten, U. [VTT Industrial Systems, Espoo (Finland); Foehl, J.; Weissenberg, T. [Staatliche Materialpruefungsanstalt, MPA, Stuttgart (Germany); Gomez-Briceno, D.; Lapena, J. [Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, CIEMAT, Madrid (Spain); Ritter, S.; Seifert, H.P. [Paul Scherrer Institute, PSI, Villigen (Switzerland)

    2004-07-01

    One of the ageing phenomena of pressure boundary components of light water reactors (LWRs) is environmentally-assisted cracking (EAC). The project CASTOC (5. Framework Programme of the EU) was launched September 2000 with six European partners and terminated August 2003. It focused in particular on the EAC behaviour of low-alloy steels (LAS) and to some extent to weld metal, heat affected zone and the influence of an austenitic cladding. The main objective was directed to the clarification of crack growth behavior of LAS in high-temperature water due to EAC under constant load (steady-state power operation), to study the effect of transient conditions (during operation or start-up/shut-down of a plant) using their impact on time-based and cycle-based crack growth rates and to a more detailed understanding of the acting mechanisms. Autoclave tests were performed with Western and Russian type reactor pressure vessel steels under simulated boiling water reactor (BWR)/normal water chemistry (NWC) and pressurized water reactor (WWER) conditions. The investigations were performed with fracture mechanics specimens of different sizes and geometries. The applied loading comprised cyclic loads, static loads and load spectra where the static load was periodically interrupted by partial unloading. With regard to water chemistry, the oxygen content (WWER) and impurities of sulphate and chlorides (BWR) were varied beyond allowable limits for continuous operation. The current paper summarizes the most important crack growth results obtained under simulated WWER conditions. The influence of oxygen content and the effect of specimen size (C(T)25 versus C(T)50 specimens) on the crack growth rates are shown. The results are discussed in the context of the current crack growth rate curves in the corresponding nuclear codes. (authors)

  7. 77 FR 17418 - Galvanized Steel Wire From the People's Republic of China: Final Affirmative Countervailing Duty...

    Science.gov (United States)

    2012-03-26

    ... Within Liaoning Province 14. VAT Deduction on Fixed Assets 15. Import Tariff and VAT Exemptions for FIEs... ``Productive'' FIEs 28. Income Tax Exemption Program for Export-Oriented FIEs 29. Local Income Tax Exemption and Reduction Programs for ``Productive'' FIEs 30. Preferential Tax Programs for FIEs Recognized as...

  8. Investigation of Materials for Waterproofing Leaky Corrugated Galvanized Steel-Arch Magazines from the Inside.

    Science.gov (United States)

    1982-03-01

    and it was satisfactory. Majority of leaks were at the base where metal was embedded . Has a better idea on the ventilation system. Condensation is...Library ATTM: Chief. SAlEN Ohio River 45201 Nashville 37202 ATT: Laboratory Comander (Code 2636) 93555 AIN: Chief. ORNED-F ATTN: Chief, Engr Div Naval...727 ATTN: Ensign Jerry Richardson San Bruno, CA 94066 Naval Air Station Alameda, CA 94501 Commanding Officer ATTN: Mr. Clyde Bradley Comanding Officer

  9. CORROSION BEHAVIOR OF A CONVERSION COATING BASED ON ZIRCONIUM AND COLORANTS ON GALVANIZED STEEL BY ELECTRODEPOSITION

    Directory of Open Access Journals (Sweden)

    Josiane Soares Costa

    2015-06-01

    Full Text Available Corrosion performance of Zr-based coating on substrates obtained by zinc electrodeposition in an alkaline bath is compared to chromate coatings (Cr III and Cr VI. The “nano Zr” is a conversion coating formed by immersion in a hexafluorozirconic acid solution. Since the “nano Zr” coating is transparent, the addiction of a colorant provides color to the surface. In this case, the colorant, when applied after the conversion coating, conferred the yellow color to the surface. The coating produced improves the corrosion protection of the substrate. For this study the samples were analyzed by electrochemical impedance spectroscopy (EIS and accelerated corrosion test in a humidity chamber. The results showed similar behaviors between the “nano Zr”, colorant and the chromate (Cr III coating. Therefore this kind of conversion coating is a promising substitute for chromate coatings.

  10. An electrochemical study of the delamination of polymer coatings on galvanized steel

    Energy Technology Data Exchange (ETDEWEB)

    Ogle, K. [Arcelor Research, SA, Maizieres-les-Metz (France)]. E-mail: kevin.ogle@irsid.arcelor.com; Morel, S. [Arcelor Research, SA, Maizieres-les-Metz (France); Meddahi, N. [Arcelor Research, SA, Maizieres-les-Metz (France)

    2005-08-01

    The relationship between the rate of polymer delamination and the intensity of either anodic or cathodic current under the paint has been investigated for the zinc/surface treatment/polymer system by using a special electrochemical cell. Three types of surface treatment were investigated: simple alkaline degreasing, trication phosphating, and a chromate free conversion coating. Significant differences were observed for the three substrates. The alkaline resistance of the conversion coatings was determined using an ICP atomic emission spectroelectrochemical method. The results are interpreted in terms of the differing chemical stability of the conversion layers towards hydroxide generated by oxygen reduction.

  11. Evaluation of Galvanized and Galvalume/Paint Duplex Coating Systems for Steel Building Panels

    National Research Council Canada - National Science Library

    Race, Timothy

    2002-01-01

    ...) or silicone modified polyester (SMP). Specimens having these coating systems were subjected to ASTM B 117, conventional salt spray exposure testing and ASTM D 5894 Testing in the laboratory, which combines the environmental effects...

  12. Chemical pretreatment of continuous galvanized steel sheet in the automotive industry

    OpenAIRE

    Kuhm, P.

    2013-01-01

    Since several years, new products appeared on the market replacing classic phosphate – based conversioncoatings. This presentation will focus on the replacement of tricationic zinc phosphating systems for theautomotive industry. The basic chemistry and coating properties are presented.In the second part of the presentation, an outlook will be given on anti-corrosion packages for the comingdecade. An example of a very lean automotive paint shop will be discussed.

  13. 76 FR 23564 - Galvanized Steel Wire From the People's Republic of China: Initiation of Countervailing Duty...

    Science.gov (United States)

    2011-04-27

    .... Provision of Electricity for LTAR C. Income and Other Direct Taxes 1. Income Tax Credits for Domestically... support, the statute directs the Department to look to producers and workers who produce the domestic like... definition regarding the domestic like product (section 771(10) of the Act), they do so for different...

  14. Obtention and Characterization of Silane based Films for the Protection of Galvanized Steel

    OpenAIRE

    Kunst, Sandra Raquel; Matos Mandujano, José Fidel; Korb, Matias de Angelis; Malfatti, Célia de Fraga

    2011-01-01

    Se presenta un estudio del comportamiento de películas de silanos Gamma-Aminopropyl tirethoxysilano y del N-(Beta-Aminoethyl)-Gamma-Aminopropyl trimethoxysilano aplicados por el proceso de revestimiento por inmersión (dip-coating) sobre el acero galvanizado. Se usan los mecanismos de curado térmico y curado por irradiación ultravioleta. Los substratos y revestimientos a base de zinc reciben normalmente un tratamiento de superficie para mejorar la resistencia a la corrosión, pero usan cromo he...

  15. Numerical Simulation of Galvanic Corrosion Caused by Shaft Grounding Systems in Steel Ship Hulls

    National Research Council Canada - National Science Library

    Wang, Y

    2005-01-01

    The shaft grounding systems used on board HMC ships have substantially reduced the shaft-to-hull resistance and, thus, improved the performance of the shipboard impressed current cathodic protection (ICCP) system...

  16. Corrosion Degradation of Coated Aluminum Alloy Systems through Galvanic Interactions

    Science.gov (United States)

    2017-07-19

    CLASSIFICATION ... steel  316  fasteners  when  coated  with  either  a  chromated  (chromate  conversion  coating,   chromate-­‐rich  primer...aluminum  alloy   substrates   and   stainless   steel   fasteners   in   the  presence  of  an   intentional

  17. Fiber Finishes for Improving Galvanic Resistance of Imide-Based Composites

    National Research Council Canada - National Science Library

    Allred, R. E

    1998-01-01

    The objective of this program is the development and demonstration of galvanic corrosion resistant carbon/ BMI composites through the use of reactive finishes to form coatings that isolate the carbon...

  18. Thin film galvanic cell with RbAg4I5 solid electrolyte

    International Nuclear Information System (INIS)

    Bodnaruk, L.I.; Danilov, A.V.; Kulinkovich, V.E.; Aleskovskij, V.B.

    1975-01-01

    In order to decrease the size and weight and to increase the specific capacity and energy of galvanic cells, some solid electrolytes in the form of thin films are proposed. The galvanic cells were prepared by a combined method: the cathodic and anodic materials (Te and Ag) were evaporated under vacuo to cover an electrolyte layer, the latter being obtained by impregnating the porous materials with RbAg 4 I 5 acetonic solution. The most specific charge curves of the galvanic cells at various current densities are given: specific energy of the samples was 0.2 to 0.7 watt-h/kg, their capacity being 0.1 to 0.2 mah. Behaviour of the cells when stored (that of Ag(RbAg 4 I 5 ) interface in particular) was investigated, namely, the effect of the storage time on the capacity and internal resistance of the galvanic cell

  19. Galvanic Vestibular Stimulation (GVS) as an Analogue of Post-flight Sensorimotor Dysfunction

    Data.gov (United States)

    National Aeronautics and Space Administration — Aim 1A (complete): Tolerance to GVS. Dilda, V, MacDougall HG, Moore, ST. Tolerance to extended Galvanic vestibular stimulation: optimal exposure for astronaut...

  20. Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel

    DEFF Research Database (Denmark)

    Hilbert, Lisbeth Rischel

    2000-01-01

    Abstract Monitoring Techniques for Microbially Influenced Corrosion of Carbon Steel Microbially influenced corrosion (MIC) of carbon steel may occur in media with microbiological activity of especially sulphate-reducing bacteria, e.g. on pipelines buried in soil and on marine structures. MIC...... of carbon steel must be monitored on-line in order to provide an efficient protection and control the corrosion. A number of monitoring techniques is industrially used today, and the applicability and reliability of these for monitoring MIC is evaluated. Coupons and ER are recommended as necessary basic...... corrosion rates, when biofilm and corrosion products cover the steel surface. However, EIS might be used for detection of MIC. EN is a suitable technique to characterise the type of corrosion attack, but is unsuitable for corrosion rate estimation. The concentric electrodes galvanic probe arrangement...

  1. Studies into the Factors that Affects the Service Integrity of Galvanizing Kettle

    Directory of Open Access Journals (Sweden)

    Muhammed Olawale Hakeem AMUDA

    2008-12-01

    Full Text Available The finding of studies into the factors that affects optimal performance of galvanizing kettle is presented in this paper. The production schedule and history of a failed galvanizing kettle for 3-consecutively years in a hot-dip galvanizing industry was collated and analyzed. The analysis of the collated data revealed that average galvanizing temperatures for the 3-year under review were 483.9°C (2003, 482.25°C (2004 and 482°C (2005 respectively. The amount of flux, and dross produced in the corresponding years were 169.15kg and 31.6 tons, 56.31kg and 10.5 tons and 101.14 and 18.91 tonnes for 2003, 2004 and 2005 respectively. During these years, zinc consumed averaged 647, 334 and 446 tonnes respectively.Stochiometry evaluation of flux, and dross in a hot-dip galvanizing process determined flux required as 60 kg/year and dross produced as 90 slabs / month.The study revealed that the lifespan of galvanizing kettle is greatly reduced by temperature fluctuation, dross formation, excess flux additions and combinations of these factors.It is recommended that improved service integrity of galvanizing kettle is assured at galvanizing temperature of 460°C, flux consumption of 0.15 –0.20kg daily and constant removal of dross at 3-5 slabs per day. This reduces the formation of skim lines, which leads to pits on the walls of the kettle.

  2. The Galvanic Corrosion of Graphite Epoxy Composite Materials Coupled with Alloys

    Science.gov (United States)

    1975-12-01

    between them due to this potential difference (Ref 6:29). Basic corrosion textbooks describe galvanic corrosion as one of the primary forms of corrosion...from the Nernst equa- tion is the sign of the free energy change since this determines the spontaneity of the redox reaction. In an electrochemical...prediction states that corrosion will not take place unless the spon- taneous direction of a redox reaction indicates oxidation. Thus EMF and galvanic

  3. Challenges in Special Steel Making

    Science.gov (United States)

    Balachandran, G.

    2018-02-01

    Special bar quality [SBQ] is a long steel product where an assured quality is delivered by the steel mill to its customer. The bars have enhanced tolerance to higher stress application and it is demanded for specialised component making. The SBQ bars are sought for component making processing units such as closed die hot forging, hot extrusion, cold forging, machining, heat treatment, welding operations. The final component quality of the secondary processing units depends on the quality maintained at the steel maker end along with quality maintained at the fabricator end. Thus, quality control is ensured at every unit process stages. The various market segments catered to by SBQ steel segment is ever growing and is reviewed. Steel mills need adequate infrastructure and technological capability to make these higher quality steels. Some of the critical stages of processing SBQ and the critical quality maintenance parameters at the steel mill in the manufacture has been brought out.

  4. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position

    Directory of Open Access Journals (Sweden)

    Hong Ju

    2018-02-01

    Full Text Available The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2, titanium (TA2, and 316L stainless steel (316L SS. These electrodes were used with artificial seawater at different temperatures. The potential and current–density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled system. The TA2 wires acted as cathodes and were protected; the 316L SS wires acted as secondary cathodes. The temperature and electrode arrangement have important effects on the galvanic corrosion of the three-metal coupled system. The corrosion current of the HAl77-2 increased with temperature indicating enhanced anode corrosion at higher temperature. In addition, the corrosion of HAl77-2 was more significant when the HAl77-2 wires were located in the middle of the coupled system than with the other two metal arrangement styles.

  5. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position.

    Science.gov (United States)

    Ju, Hong; Yang, Yuan-Feng; Liu, Yun-Fei; Liu, Shu-Fa; Duan, Jin-Zhuo; Li, Yan

    2018-02-28

    The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2), titanium (TA2), and 316L stainless steel (316L SS). These electrodes were used with artificial seawater at different temperatures. The potential and current-density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled system. The TA2 wires acted as cathodes and were protected; the 316L SS wires acted as secondary cathodes. The temperature and electrode arrangement have important effects on the galvanic corrosion of the three-metal coupled system. The corrosion current of the HAl77-2 increased with temperature indicating enhanced anode corrosion at higher temperature. In addition, the corrosion of HAl77-2 was more significant when the HAl77-2 wires were located in the middle of the coupled system than with the other two metal arrangement styles.

  6. Mapping the Galvanic Corrosion of Three Metals Coupled with a Wire Beam Electrode: The Influence of Temperature and Relative Geometrical Position

    Science.gov (United States)

    Liu, Yun-Fei; Liu, Shu-Fa; Duan, Jin-Zhuo

    2018-01-01

    The local electrochemical properties of galvanic corrosion for three coupled metals in a desalination plant were investigated with three wire-beam electrodes as wire sensors: aluminum brass (HAl77-2), titanium (TA2), and 316L stainless steel (316L SS). These electrodes were used with artificial seawater at different temperatures. The potential and current–density distributions of the three-metal coupled system are inhomogeneous. The HAl77-2 wire anodes were corroded in the three-metal coupled system. The TA2 wires acted as cathodes and were protected; the 316L SS wires acted as secondary cathodes. The temperature and electrode arrangement have important effects on the galvanic corrosion of the three-metal coupled system. The corrosion current of the HAl77-2 increased with temperature indicating enhanced anode corrosion at higher temperature. In addition, the corrosion of HAl77-2 was more significant when the HAl77-2 wires were located in the middle of the coupled system than with the other two metal arrangement styles. PMID:29495617

  7. Importance of crevices formed between tubes and tube plate for the operational behaviour of heat exchangers

    International Nuclear Information System (INIS)

    Achten, N.; Herbsleb, G.; Wieling, N.

    1986-01-01

    It must be guaranteed by construction and manufacture of heat exchangers that primary and secondary medium are completely separated from each other. When this requirement is fullfilled, the operational use of heat exchangers can be impaired by corrosion reactions within the crevice formed between tube and tube plate which may result in corrosion damage. The various techniques which are in use to connect tubes and tube plate and which are described in the present report, must be valued with respect to the tightness of the connection as well as to the formation of crevices between tubes and tube plate. Corrosion resistant copperbase alloys and stainless steels are the most important materials which are in use for the construction of heat exchangers. The mechanisms of crevice corrosion with unalloyed and low alloy carbon steels, stainless steels, and mixed connections between tube and tube plate with these materials are described in detail. Crevice corrosion may be caused also by the formation of galvanic cells between materials of differing electrochemical response. Furthermore, the concentration of aggressive media in crevices between tubes and tube plate can lead to corrosion damage of heat exchanger tubes. For the service operation of heat exchangers without any hazard of corrosion damage in crevices between tubes and tube plate, such crevices must be avoided by proper construction and manufacture. As a model for suitable measures to avoid crevices, the manufacture of steam generators for PWR's is described. (orig.) [de

  8. EFFECT OF OPERATING CONDITIONS ON THIN LAYERS OF TITANIUM POSED ON STEEL 100C6 SUBSTRATES WITH PVD METHOD

    Directory of Open Access Journals (Sweden)

    R. Gheriani

    2015-08-01

    Full Text Available We proposed to prepare hard coatings based on titanium carbides by deposition of thin layers of pure Ti by sputtering method on steel substrates 100C6 of 1 %mass carbon. The samples were annealed under vacuum in the temperature range of 400 ° C to 1000 ° C, in order to activate the reaction between the two parts of the system which results the formation of carbides of Ti due to the diffusion of carbon from the substrate towards deposited  layers. We therefore note an improvement in mechanical properties such as hardness. To demonstrate the effect of deposition parameters, we have prepared two series, the first one with a high pressure of argon and remarkable energy of extracted atoms, and in the case of the second one the pressure and kinetic energy are relatively less important. The samples of series 2 show features more important: a compact structure and good mechanical properties. The reaction between thin films and substrates is studied by x-ray diffraction (XRD, scanning electron microscopy (SEM. The measurements of microhardness were performed with the Vickers method.

  9. Methanol oxidation at platinized copper particles prepared by galvanic replacement

    Directory of Open Access Journals (Sweden)

    Ioanna Mintsouli

    2016-04-01

    Full Text Available Bimetallic Pt-Cu particles have been prepared by galvanic replacement of Cu precursor nanoparticles, upon the treatment of the latter with a chloro-platinate acidic solution. The resulting particles, typically a few tens of nm large, were supported on high surface area carbon (Vulcan® XC–72R, Cabot and tested as electrodes. Surface electrochemistry in deaerated acid solutions was similar to that of pure Pt, indicating the existence of a Pt shell (hence the particles are denoted as Pt(Cu. Pt(Cu/C supported catalysts exhibit superior carbon monoxide and methanol oxidation activity with respect to their Pt/C analogues when compared on a per electroactive surface area basis, due to the modification of Pt activity by Cu residing in the particle core. However, as a result of large particle size and agglomeration phenomena, Pt(Cu/C are still inferior to Pt/C when compared on a mass specific activity basis.

  10. Galvanic corrosion: a microsystems device integrity and reliability concern

    Science.gov (United States)

    Miller, David C.; Hughes, William L.; Wang, Zhong L.; Gall, Ken; Stoldt, Conrad R.

    2006-01-01

    We have studied the corrosion of phosphorus-doped polySi when contacted to a gold metallization layer and exposed to various hydrofluoric acid (HF) based chemistries, including mixtures with HCl, C IIH 6O, H IIO, NH 4F, Triton-X-100, as well as vapor-based HF. Here, we utilize optical-, electron-, and atomic-force-microscopy, optical interferometry, as well as instrumented indentation ("nanoindentation") to characterize test and reference specimens exposed to the various HF solutions. These measurements provide information concerning the appearance, roughness, physical dimensions, hardness, elastic modulus, and reverse phase transformation activity of the various polysilicon specimens. In general, some of the chemistries produced time-dependent darkening or "staining" visibly seen on free surfaces, roughening and attack at grain boundaries, nano-scale pitting of the free surfaces, decrease in thickness, decrease in hardness and mechanical modulus, and diminished elbow and reverse excursion activity for those silicon specimens electrically connected to metal. Change in performance is attributed to the formation of a galvanic cell during the HF immersion, and the corresponding damage driven by an anodic current. The results here can be used to explain previous work, which focused on the change in performance of designated MEMS diagnostic structures.

  11. Use of galvanic vestibular feedback for a balance prosthesis.

    Science.gov (United States)

    Peterka, Robert J

    2012-01-01

    Activation of vestibular afferents by a bilateral bipolar galvanic vestibular stimulus (GVS) evokes medial-lateral (ML) body sway. By applying a GVS feedback signal that is a function of measured ML head motion, the potential exists for GVS to restore a useful vestibular contribution to ML balance control in vestibular-deficient subjects who remain responsive to GVS. A key to developing an effective balance prosthesis using GVS is to determine the functional relationship between GVS and its influence on the brain's internal estimate of head motion. We describe how a model-based interpretation of GVS-evoked body sway can be used to identify this functional relationship. Results indicate that the GVS-evoked internal motion estimate is effectively a low-pass filtered version of the GVS current. With preliminary data, we demonstrate that GVS feedback, compensated for the identified low-pass characteristics, can either remove the ability of a subject with normal vestibular function to use vestibular information for balance control, or can restore the ability of a subject with bilateral vestibular loss to maintain balance in a condition requiring vestibular information for balance control.

  12. Synthesis of chromium containing pigments from chromium galvanic sludges

    International Nuclear Information System (INIS)

    Andreola, F.; Barbieri, L.; Bondioli, F.; Cannio, M.; Ferrari, A.M.; Lancellotti, I.

    2008-01-01

    In this work the screening results of the scientific activity conducted on laboratory scale to valorise chromium(III) contained in the galvanic sludge as chromium precursor for ceramic pigments are reported. The valorisation of this waste as a secondary raw material (SRM) is obtained by achievement of thermal and chemical stable crystal structures able to color ceramic material. Two different pigments pink CaCr 0.04 Sn 0.97 SiO 5 and green Ca 3 Cr 2 (SiO 4 ) 3 were synthesized by solid-state reactions using dried Cr sludge as chromium oxide precursor. The obtained pigments were characterized by X-ray diffraction and SEM analysis. Furthermore the color developed in a suitable ceramic glaze was investigated in comparison with the color developed by the pigments prepared from pure Cr 2 O 3 . The characterization carried out corroborates the thermal and chemical stability of the synthesized pigments and, especially for the Cr-Sn pink pigment, the powders develop an intense color that is very similar to the color developed by the pigments obtained starting from pure Cr 2 O 3

  13. Galvanic enhancement for high pressure leaching of chalcopyrite

    Directory of Open Access Journals (Sweden)

    Kim D.H.

    2016-01-01

    Full Text Available This study was conducted to evaluate the galvanic enhancement of the pressure oxidation (POX leaching of a chalcopyrite/chalcocite concentrate, which is believed to take place via a redox reaction. Cu recoveries of >90% could be achieved during POX leaching of this chalcopyrite/chalcocite concentrate at 200°C and 0.7 MPa initial oxygen pressure within 2h in a pressure reactor lined with titanium, which were 18-28% higher than for the same leaching using the teflon liner. A slow heating time seems to produce more sulphur coating, reducing the leaching performance, yielding much lower Cu recovery when the teflon lining was used, although this does not greatly affect the other case when the reactor was lined with titanium. The introduction of an electronic conductor, in this case the titanium surface, is believed to enhance this redox process, in which the oxidation of copper minerals and sulphur to sulphate at the anodic sites (mineral surface encountered during POX leaching takes place simultaneously with the reversible oxidation/reduction of the Fe2+/Fe3+couple and oxygen reduction on titanium.

  14. The sorption-chromaticity determination of Fe(III in the waters of the galvanic production

    Directory of Open Access Journals (Sweden)

    P. T. Sukhanov

    2017-01-01

    Full Text Available Developed out express Sorption-colorimetric methods for the determination of iron in water, based on the sorption concentration of detecting component of the solution impregnated in the polyurethane foam, the formation on the surface of a colored compound and then its definition in the sorbent matrix by measuring color intensity or chromaticity characteristics. The first method is based on determining the agitation of the sample solution with a tablet impregnated with PPU known mass, from which the air bubbles are removed, the second dynamic – by sampling by suction solution in the analytical cartridge impregnated with PPU. Discoloration polyurethane indicates the presence of iron (III in water, and its content was determined by comparing the color intensity of foam tablets previously prepared color chart or chromaticity characteristics comparing analyte and standard solutions. The conditions of sorption-photometric analysis: the concentration of the photometric reagent impregnated in the foam, the degree of loading it impregnant, the phases of contact, the acidity of the environment. When using analytical cartridges lower limit of detection is 2 times higher, and the measurement error to 3.5% lower than with the tablets. The proposed test methods using polyurethane enable to carry out the analysis of wash water and the total flow of galvanizing plant before and after neutralization station “on the spot”, without the use of sophisticated instruments and highly skilled operator.

  15. Determination of the most favourable operating techniques for the radiography of very thick steel plates (98 to 238 mm) by means of the 6-MeV linear accelerator

    International Nuclear Information System (INIS)

    Lesbre, F.; Levillain, M.; Cocoual, N.

    1983-01-01

    The capabilities of a 6 MeV linear accelerator applied to the radiography of very thick steel plates are analysed and compared to the results obtained with cobalt 60 sources. The influence of the operating technique (screens and filters) is discussed [fr

  16. Petition to Object to the Proposed Operating Permit for Consolidated Environmental Management, Inc., Nucor Steel Facility in Romeville, Louisiana

    Science.gov (United States)

    This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  17. Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace.

    Science.gov (United States)

    Keane, Michael; Siert, Arlen; Stone, Samuel; Chen, Bean T

    2016-01-01

    Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr(6+)). Elemental manganese, nickel, chromium, iron emissions per unit length of weld, and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered, and analyzed by inductively coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr(6+). GMAW processes used were Surface Tension Transfer, Regulated Metal Deposition, Cold Metal Transfer, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr(6+) ranged from 50-7800 µg/min, and Cr(6+) generation rates per g electrode ranged from 1-270 µg/g. Elemental Cr generation rates spanned 13-330 µg/g. Manganese emission rates ranged from 50-300 µg/g. Nickel emission rates ranged from 4-140 µg/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as five times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes in this

  18. Galvanic interactions of HE15 /MDN138 & HE15 /MDN250 alloys in natural seawater

    Science.gov (United States)

    Parthiban, G. T.; Subramanian, G.; Muthuraman, K.; Ramakrishna Rao, P.

    2017-06-01

    HE15 is a heat treatable high strength alloy with excellent machinability find wide applications in aerospace and defence industries. In view of their excellent mechanical properties, workability, machinability, heat treatment characteristics and good resistance to general and stress corrosion cracking, MDN138 & MDN250 have been widely used in petrochemical, nuclear and aerospace industries. The galvanic corrosion behaviour of the metal combinations HE15 /MDN138 and HE15 /MDN250, with 1:1 area ratio, has been studied in natural seawater using the open well facility of CECRI's Offshore Platform at Tuticorin for a year. The open circuit potentials of MDN138, MDN250 and HE15 of the individual metal, the galvanic potential and galvanic current of the couples HE15 /MDN138 and HE15 /MDN250 were periodically monitored throughout the study period. The calcareous deposits on MDN138 and MDN250 in galvanic contact with HE15 were analyzed using XRD. The electrochemical behaviors of MDN138, MDN250 and HE15 in seawater have been studied using an electrochemical work station. The surface characteristics of MDN138 and MDN250 in galvanic contact with HE15 have been examined with scanning electron microscope. The results of the study reveal that HE15 offered required amount of protection to MDN138 & MDN250.

  19. Steel structures for nuclear facilities

    International Nuclear Information System (INIS)

    1993-01-01

    In the guide the requirements concerning design and fabrication of steel structures for nuclear facilities and documents to be submitted to the Finnish Centre for Radiation and Nuclear Safety (STUK) are presented. Furthermore, regulations concerning inspection of steel structures during construction of nuclear facilities and during their operation are set forth

  20. Galvanic Corrosion of and Ion Release from Various Orthodontic Brackets and Wires in a Fluoride-containing Mouthwash

    Directory of Open Access Journals (Sweden)

    Soodeh Tahmasbi

    2015-09-01

    Full Text Available Background and aims. This study compared the galvanic corrosion of orthodontic wires and brackets from various man-ufacturers following exposure to a fluoride mouthwash. Materials and methods. This study was conducted on 24 lower central incisor 0.022” Roth brackets of four different commercially available brands (Dentaurum, American Orthodontics, ORJ, Shinye. These brackets along with stainless steel (SS or nickel-titanium (NiTi orthodontic wires (0.016", round were immersed in Oral-B mouthwash containing 0.05% sodium fluoride for 28 days. The electric potential (EP difference of each bracket-wire couple was measured with a Satu-rated Calomel Reference Electrode (Ag/AgCl saturated with KCl via a voltmeter. The ions released in the electrolyte weremeasured with an atomic absorption spectrometer. All the specimens were assessed under a stereomicroscope and speci-mens with corrosion were analyzed with scanning electron microscopy (SEM. Data were analyzed using ANOVA. Results. The copper ions released from specimens with NiTi wire were greater than those of samples containing SS wire. ORJ brackets released more Cu ions than other samples. The Ni ions released from Shinye brackets were significantly more than those of other specimens (P < 0.05. Corrosion rate of brackets coupled with NiTi wires was higher than that of brack-ets coupled with SS wires. Light and electron microscopic observations showed greater corrosion of ORJ brackets. Conclusion. In fluoride mouthwash, Shinye and ORJ brackets exhibited greater corrosion than Dentaurum and American Orthodontics brackets. Stainless steel brackets used with NiTi wires showed greater corrosion and thus caution is recom-mended when using them.

  1. Galvanic Corrosion of and Ion Release from Various Orthodontic Brackets and Wires in a Fluoride-containing Mouthwash.

    Science.gov (United States)

    Tahmasbi, Soodeh; Ghorbani, Mohammad; Masudrad, Mahdis

    2015-01-01

    Background and aims. This study compared the galvanic corrosion of orthodontic wires and brackets from various manufacturers following exposure to a fluoride mouthwash. Materials and methods. This study was conducted on 24 lower central incisor 0.022" Roth brackets of four different commercially available brands (Dentaurum, American Orthodontics, ORJ, Shinye). These brackets along with stainless steel (SS) or nickel-titanium (NiTi) orthodontic wires (0.016", round) were immersed in Oral-B mouthwash containing 0.05% sodium fluoride for 28 days. The electric potential (EP) difference of each bracket-wire couple was measured with a Saturated Calomel Reference Electrode (Ag/AgCl saturated with KCl) via a voltmeter. The ions released in the electrolyte weremeasured with an atomic absorption spectrometer. All the specimens were assessed under a stereomicroscope and specimens with corrosion were analyzed with scanning electron microscopy (SEM). Data were analyzed using ANOVA. Results. The copper ions released from specimens with NiTi wire were greater than those of samples containing SS wire. ORJ brackets released more Cu ions than other samples. The Ni ions released from Shinye brackets were significantly more than those of other specimens (P wires was higher than that of brackets coupled with SS wires. Light and electron microscopic observations showed greater corrosion of ORJ brackets. Conclusion. In fluoride mouthwash, Shinye and ORJ brackets exhibited greater corrosion than Dentaurum and American Orthodontics brackets. Stainless steel brackets used with NiTi wires showed greater corrosion and thus caution is recommended when using them.

  2. Steels for nuclear power. I

    International Nuclear Information System (INIS)

    Bohusova, O.; Brumovsky, M.; Cukr, B.; Hatle, Z.; Protiva, K.; Stefec, R.; Urban, A.; Zidek, M.

    1976-01-01

    The principles are listed of nuclear reactor operation and the reactors are classified by neutron energy, fuel and moderator designs, purpose and type of moderator. The trend and the development of light-water reactor applications are described. The fundamental operating parameters of the WWER type reactors are indicated. The effect is discussed of neutron radiation on reactor structural materials. The characteristics are described of steel corrosion due to the contact of the steel with steam or sodium in the primary coolant circuit. The reasons for stress corrosion are given and the effects of radiation on corrosion are listed. The requirements and criteria are given for the choice of low-alloy steel for the manufacture of pressure vessels, volume compensators, steam generators, cooling conduits and containment. A survey is given of most frequently used steels for pressure vessels and of the mechanical and structural properties thereof. The basic requirements for the properties of steel used in the primary coolant circuit are as follows: sufficient strength in operating temperature, toughness, good weldability, resistance to corrosion and low brittleness following neutron irradiation. The materials are listed used for the components of light-water and breeder reactors. The production of corrosion-resistant steels is discussed with a view to raw materials, technology, steel-making processes, melting processes, induction furnace steel-making, and to selected special problems of the chemical composition of steels. The effects are mainly discussed of lead, bismuth and tin as well as of some other elements on hot working of high-alloy steels and on their structure. The problems of corrosion-resistant steel welding and of pressure vessel cladding are summed up. Also discussed is the question of the concept and safeguards of the safety of nuclear installation operation and a list is presented of most commonly used nondestructive materials testing methods. The current

  3. Spot welding of aluminium alloy sheets to coated steel sheets. Kakushu mekki koban to arumi gokin no spot yosetsusei

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, S.; Fukumura, K.; Soga, S. (Nisshin Steel Co. Ltd., Tokyo (Japan))

    1994-03-31

    Welding aluminum alloy sheets with coated steel sheets has become used frequently in association with weight reduction in automobiles. This paper describes investigations on the effects of spot welding aluminum alloy sheets with different kinds of coated steel sheets on optimal welding conditions and weld strength. An AC single-phase spot welding machine was used for an experiment using an aluminum alloy(5052)with a thickness of 1 mm(referred to as A)and different coated steel sheets with a thickness of 0.8 mm(referred to as B). The result may be summarized as follows: the weldable value of the electric current is closer to that for between the B steel sheets than the middle of that for between the As and between Bs; while the weldable current range is affected little by the coating materials when a CF electrode is used, it grows greater in aluminum coated steel sheets and hot-dip galvanized steel sheets than in alloyed hot-dip galvanized steel sheets and cold-rolled steel sheets when an R-type electrode is used; influence of the coating materials was observed in tensile shear strength and cross tensile shear strength; and any combination of metals shows fatigue strength lower than that in the A-A combination in a fatigue test of cross tensile system. 5 refs., 12 figs., 6 tabs.

  4. Photo-galvanic effect in Bi2Se3 thin films with ionic liquid gating

    Science.gov (United States)

    Pan, Yu; Richardella, Anthony; Lee, Joon Sue; Flanagan, Thomas; Samarth, Nitin

    2013-03-01

    A key challenge in three dimensional (3D) topological insulators (TIs) is to reveal the helical spin-polarized surface states via electrical transport measurements. A recent study [Nature Nanotech. 7, 96 (2012)] showed that circularly polarized light can be used to generate and control photocurrents in the 3D TI Bi2Se3, even at photon energies that are well above the bulk band gap. Symmetry considerations suggest that this ``photo-galvanic effect'' arises purely from photo-currents induced in the surface Dirac states. To gain insights into this phenomenon, we have carried out systematic measurements of the photo-galvanic effect in electrically gated MBE-grown Bi2Se3 thin films of varying thickness. By using an ionic liquid as an optically transparent gate, we map out the behavior of the photo-galvanic effect as a function of Fermi energy over a temperature range 5 K <= T <= 300 K. Supported by ONR and NSF.

  5. Electroactive Polymers as Environmentally Benign Coating Replacements for Cadmium Plating on High Strength Steels

    Science.gov (United States)

    2008-06-01

    mico -and nano- particles into the polymer film. Meghan Baronowski, Marc Pepi, Joe Hibbs and John Baronowski devised the test matrix and tested for...steel (galvanic effect) Electroplated zinc Army Voluminous white corrosion products SermeTel®(Sermatech Inc) Navy Performance hindered by complex ...geometries Zinc/nickel with E-coat topcoat Navy Performance hindered by complex geometries Zinc electroplate-alkaline bath Navy Better than acid

  6. 49 CFR 192.505 - Strength test requirements for steel pipeline to operate at a hoop stress of 30 percent or more...

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Strength test requirements for steel pipeline to...: MINIMUM FEDERAL SAFETY STANDARDS Test Requirements § 192.505 Strength test requirements for steel pipeline... as provided in paragraph (e) of this section, the strength test must be conducted by maintaining the...

  7. Prognostic investigation of galvanic corrosion precursors in aircraft structures and their detection strategy

    Science.gov (United States)

    James, Robin; Kim, Tae Hee; Narayanan, Ram M.

    2017-04-01

    Aluminum alloys have been the dominant materials for aerospace construction in the past fifty years due to their light weight, forming and alloying, and relative low cost in comparison to titanium and composites. However, in recent years, carbon fiber reinforced polymers (CFRPs) and honeycomb materials have been used in aircrafts in the quest to attain lower weight, high temperature resistance, and better fuel efficiency. When these two materials are coupled together, the structural strength of the aircraft is unparalleled, but this comes at a price, namely galvanic corrosion. Previous experimental results have shown that when CFRP composite materials are joined with high strength aluminum alloys (AA7075-T6 or AA2024-T3), galvanic corrosion occurs at the material interfaces, and the aluminum is in greater danger of corroding, particularly since carbon and aluminum are on the opposite ends of the galvanic series. In this paper, we explore the occurrence of the recognizable precursors of galvanic corrosion when CFRP plate is coupled to an aluminum alloy using SS-304 bolts and exposed to environmental degradation, which creates significant concerns for aircraft structural reliability. The galvanic corrosion software package, BEASY, is used to simulate the growth of corrosion in the designed specimen after which a microwave non-destructive testing (NDT) technique is explored to detect corrosion defects that appear at the interface of this galvanic couple. This paper also explores a loaded waveguide technique to determine the dielectric constant of the final corrosion product at the Q-band millimeter-wave frequency range (33-50 GHz), as this can be an invaluable asset in developing early detection strategies.

  8. Corrosion resistance of different metallic coatings on press-hardened steels for automotive

    Energy Technology Data Exchange (ETDEWEB)

    Dosdat, L.; Petitjean, J.; Vietoris, T. (ArcelorMittal Maizieres Automotive Products Research Centre, F-57283 Maizieres-les-Metz); Clauzeau, O. [Bohr Technologies (France)

    2011-06-15

    The corrosion resistance of laboratory press-hardened components in aluminized, galvanized or galvannealed boron steels was evaluated through VDA 621-415 cyclic test for the automotive industry. 22MnB5 uncoated steel for hot stamping and standard galvanized steel for cold forming were also included as references. Corrosion resistance after painting (cosmetic corrosion) was quantified by measuring the delamination of electro-deposited paint from scribed panels. The rusting on their edges was used for determining the cut-edge corrosion resistance. The corrosion resistance on unpainted deformed panels (perforating corrosion) was quantified by mass losses and pit depth measurements. Zinc-coated boron steels were found to be more resistant to cosmetic corrosion than the other materials, and slightly more resistant to cut-edge corrosion than the aluminized one. Red rust apparition could not be avoided due to the high iron content in all these hot-stamped coatings. The three coated boron steels showed similar performances in terms of resistance to perforation. Aluminized boron steel presents the advantage of being less sensitive to hot-stamping process deviation. Its robustness has been proved for many years on cars. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Operation PLUMBBOB. Summary Report, Test Group 57, Nevada Test Site. Extracted Version

    Science.gov (United States)

    1982-06-04

    000 fallout collectors. The sensor of each was a simple 9-inch ~ square of galvanized steel sprayed with • - alkyd resin which remained tacky for days...a . .. .. ’ . . . . . . . . • +,i ir I, I Jr "e it I r ’ r . . . . . . . . .. .. . .. a............. a,..a ~.. ... ,.a .... ,. .......... af. .i

  10. Operational modal analysis of a steel-frame, low-rise building with L-shaped construction

    Science.gov (United States)

    Sarlo, Rodrigo; Tarazaga, Pablo A.; Kasarda, Mary E.

    2017-04-01

    The Goodwin Hall Smart Infrastructure facility at Virginia Tech is a five-story "smart building" with an integrated network of 213 wired accelerometers. We utilize a subset of 68 sensors to perform high-resolution Operational Modal Analysis (OMA) of the structure under windy conditions. The low-rise, L-shaped construction and high mass, high stiffness properties of Goodwin Hall provide a unique case study in comparison to typical cases of building OMA in literature, which generally feature high-rise buildings with rectangular architectures. Our work focuses on data acquisition and feature extraction, which are two critical steps within a complete structural health monitoring approach. Our detailed methodology establishes guidelines for sensor selection and data processing applicable to this and more general cases. Modal parameters extraction using Stochastic Subspace Identification shows the first four natural frequencies, damping values, participation factors and mode shapes of the building. We hypothesize that high damping values and large differences in the participation of fundamental modes are related to the nature of the wind excitation.

  11. Effect of a Chloride Transient on the EAC Crack Growth Behaviour of Low-Alloy RPV Steels under Simulated BWR Operating Conditions (CASTOC WP 3, PSI Test 2)

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S.; Seifert, H.-P

    2002-11-01

    Within the CASTOC-project (5{sup t}h EU FW programme), the environmentally-assisted crack (EAC) growth behaviour of low-alloy reactor pressure vessel (RPV) steels is experimentally investigated under simulated transient and steady-state boiling water reactor (BWR) power operation conditions by six European laboratories. The present report is a summary of the second test of working package (WP) 3 with a NaCl transient, performed at Paul Scherrer Institut (PSI). In the first part of the experiment, an actively growing EAC crack with a crack growth rate (CGR) in the range of the 'low-sulphur SCC line' of the GE-model was generated by periodical partial unloading (PPU) in oxygenated high-temperature, high-purity water (T = 288 {sup o}C, DO = 8 ppm). Then a chloride transient of 49 ppb Cl{sup -} was applied for {approx}40 h. After this transient, the load level was reduced and the loading conditions were changed to pure cyclic loading. Thereupon a second transient with a chloride concentration of 49 ppb was applied. In both RPV steels, the first chloride transient of 49 ppb Cl{sup -} resulted in an acceleration of the EAC crack growth by more than one order of magnitude and in fast, stationary SCC crack growth during the constant load phase of the PPU cycles at K{sub I} values < 60 MPa.m{sup 1/2}. 3 h after adding chloride to the high-purity water, the EAC CGR started to increase in the high-sulphur RPV steel during the constant load phase of a PPU cycle and after 20 h a stationary EAC CGR value in the range of the 'high-sulphur SCC curve' of the GE-model was reached. After 5 h in high-purity water, the crack growth began to slow down after a partial unloading cycle and 15 h later it reached again a stationary CGR value in the range of the 'low-sulphur SCC curve' of the GE-model. The second chloride transient did not result in an acceleration of the crack growth in both investigated specimens. This was explained by crack closure effects

  12. Effect of a Chloride Transient on the EAC Crack Growth Behaviour of Low-Alloy RPV Steels under Simulated BWR Operating Conditions (CASTOC WP 3, PSI Test 2)

    International Nuclear Information System (INIS)

    Ritter, S.; Seifert, H.-P.

    2002-11-01

    Within the CASTOC-project (5 t h EU FW programme), the environmentally-assisted crack (EAC) growth behaviour of low-alloy reactor pressure vessel (RPV) steels is experimentally investigated under simulated transient and steady-state boiling water reactor (BWR) power operation conditions by six European laboratories. The present report is a summary of the second test of working package (WP) 3 with a NaCl transient, performed at Paul Scherrer Institut (PSI). In the first part of the experiment, an actively growing EAC crack with a crack growth rate (CGR) in the range of the 'low-sulphur SCC line' of the GE-model was generated by periodical partial unloading (PPU) in oxygenated high-temperature, high-purity water (T = 288 o C, DO = 8 ppm). Then a chloride transient of 49 ppb Cl - was applied for ∼40 h. After this transient, the load level was reduced and the loading conditions were changed to pure cyclic loading. Thereupon a second transient with a chloride concentration of 49 ppb was applied. In both RPV steels, the first chloride transient of 49 ppb Cl - resulted in an acceleration of the EAC crack growth by more than one order of magnitude and in fast, stationary SCC crack growth during the constant load phase of the PPU cycles at K I values 1/2 . 3 h after adding chloride to the high-purity water, the EAC CGR started to increase in the high-sulphur RPV steel during the constant load phase of a PPU cycle and after 20 h a stationary EAC CGR value in the range of the 'high-sulphur SCC curve' of the GE-model was reached. After 5 h in high-purity water, the crack growth began to slow down after a partial unloading cycle and 15 h later it reached again a stationary CGR value in the range of the 'low-sulphur SCC curve' of the GE-model. The second chloride transient did not result in an acceleration of the crack growth in both investigated specimens. This was explained by crack closure effects, which occurred in both specimens after the reduction of the load. The CGR

  13. All-Digital Galvanically-Coupled BCC Receiver Resilient to Frequency Misalignment.

    Science.gov (United States)

    Chen, Pengpeng; Yang, Huazhong; Luo, Rong; Zhao, Bo

    2017-06-01

    It is promising for wearable devices to go to a miniature size to alleviate the load of human body. One way to miniaturize the communication nodes on human body is to remove the bulky components such as antenna and crystal. Galvanically-coupled body channel communication (GC-BCC) has a great advantage over conventional wireless communications in reducing the size of wearable devices because it reuses the monitoring electrodes for signal transmission in place of antennas. To remove the crystal as well, the receiver must be immune to different types of frequency misalignments. This paper presents a GC-BCC receiver based on low power all-digital Gaussian frequency shift keying (GFSK) demodulation and clock-data recovery (CDR). A carrier tracking technique is proposed to detect and automatically adapt to the misalignment of carrier frequency. In addition, we also propose a circle-index CDR circuit to deal with the inaccuracy or drift of the clock frequency. The proposed circuit is implemented with 0.18 μm CMOS technology, and it operates at 200 kHz with a BFSK/GFSK modulation index of 1.0. Measured results show that the chip consumes 0.53 mA at a data rate of 100 kb/s. At a 10 cm body channel length, the GC-BCC receiver can tolerate a carrier misalignment up to [Formula: see text] and a clock error up to [Formula: see text], while keeping the bit error rate (BER) below 0.1%.

  14. A Student-Constructed Galvanic Cell for the Measurement of Cell Potentials at Different Temperatures

    Science.gov (United States)

    Jakubowska, Anna

    2016-01-01

    A student-made galvanic cell is proposed for temperature measurements of cell potential. This cell can be easily constructed by students, the materials needed are readily available and nontoxic, and the solution applied is in an attractive color. For this cell, the potential values are excellently reproducible at each temperature, and the…

  15. Transcranial Doppler ultrasound during galvanic labyrinth polarization depicts central vestibular processing, demonstrating bilateral vestibular projection.

    Science.gov (United States)

    Schlosser, Hans-Georg; Guldin, Wolfgang; Fritzsche, Danny; Clarke, Andrew H

    2008-07-01

    The combination of galvanic labyrinth polarization and transcranial Doppler ultrasound was employed to depict the neurovascular coupling in the cerebral vestibular areas. For galvanic stimulation, surface electrodes were attached to the right and left mastoid and two further electrodes were fixed near to each shoulder blade. Thus, each pair of electrodes (mastoid to shoulder) facilitated unilateral stimulation of the ipsilateral vestibular labyrinth. Blood flow in the middle cerebral artery and the internal carotid artery in both hemispheres was measured by means of Doppler ultrasound. The transcranial Doppler ultrasound system was head-fixed and allowed continuous monitoring of the blood flow throughout the trials. Using a series of different stimulation modes (bilateral, unilateral left, unilateral right and sham), the changes in mean blood flow velocity were evaluated by comparing baseline blood flow under resting conditions to blood flow during stimulation. A total of 18 trials were performed with each of seven volunteer subjects. Galvanic labyrinth polarization elicited a clear sensation of pendular body movement in all subjects. Significant blood flow increase (P < 0.05) in both hemispheres was observed during bilateral stimulation. Of more interest is that unilateral stimulation also elicited a significant increase in flow in both the ipsilateral and the contralateral hemispheres, demonstrating the existence of bilateral projections from each vestibular labyrinth. The combination of galvanic labyrinth polarization with transcranial Doppler ultrasound blood flow measurement provides a novel approach to the functional assessment of the vestibular system (deep cerebral structures and cortical areas). This novel technique provides a useful tool for clinical examinations.

  16. Media Research with a Galvanic Skin Response Biosensor: Some Kids Work Up a Sweat!

    Science.gov (United States)

    Clariana, Roy B.

    This study considers the galvanic skin response (GSR) of sixth-grade students (n=20) using print, video, and microcomputer segments. Subjects received all three media treatments, in randomized order. Data for analysis consisted of standardized test scores and GSR measures; a moderate positive relationship was shown between cumulative GSR and…

  17. Intracavity OptoGalvanic Spectroscopy Not Suitable for Ambient Level Radiocarbon Detection

    NARCIS (Netherlands)

    Paul, Dipayan; Meijer, Harro

    2015-01-01

    IntraCavity OptoGalvanic Spectroscopy as a radiocarbon detection technique was first reported by the Murnick group at Rutgers University, Newark, NJ, in 2008. This technique for radiocarbon detection was presented with tremendous potentials for applications in various fields of research.

  18. Standard guide for conducting and evaluating galvanic corrosion tests in electrolytes

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1981-01-01

    1.1 This guide covers conducting and evaluating galvanic corrosion tests to characterize the behavior of two dissimilar metals in electrical contact in an electrolyte under low-flow conditions. It can be adapted to wrought or cast metals and alloys. 1.2 This guide covers the selection of materials, specimen preparation, test environment, method of exposure, and method for evaluating the results to characterize the behavior of galvanic couples in an electrolyte. Note 1—Additional information on galvanic corrosion testing and examples of the conduct and evaluation of galvanic corrosion tests in electrolytes are given in Refs (1) through (7). 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicabil...

  19. The Effect of Galvanic Vestibular Stimulation on Postural Response of Down Syndrome Individuals on the Seesaw

    Science.gov (United States)

    Carvalho, R. L.; Almeida, G. L.

    2011-01-01

    In order to better understand the role of the vestibular system in postural adjustments on unstable surfaces, we analyzed the effects of galvanic vestibular stimulation (GVS) on the pattern of muscle activity and joint displacements (ankle knee and hip) of eight intellectually normal participants (control group--CG) and eight control group…

  20. Self-oscillating Galvanic Isolated Bidirectional Very High Frequency DC-DC Converter

    DEFF Research Database (Denmark)

    Pedersen, Jeppe Arnsdorf; Madsen, Mickey Pierre; Knott, Arnold

    2015-01-01

    This paper describes a galvanic isolated bidirectional Very High Frequency (VHF = 30 MHz - 300MHz) ClassE converter. The reason for increasing the switching frequency is to minimize the passive components in the converter. To make the converter topology bidirectional the rectifier has to be synch...

  1. Tool steels

    DEFF Research Database (Denmark)

    Højerslev, C.

    2001-01-01

    On designing a tool steel, its composition and heat treatment parameters are chosen to provide a hardened and tempered martensitic matrix in which carbides are evenly distributed. In this condition the matrix has an optimum combination of hardness andtoughness, the primary carbides provide...... resistance against abrasive wear and secondary carbides (if any) increase the resistance against plastic deformation. Tool steels are alloyed with carbide forming elements (Typically: vanadium, tungsten, molybdenumand chromium) furthermore some steel types contains cobalt. Addition of alloying elements...... serves primarily two purpose (i) to improve the hardenabillity and (ii) to provide harder and thermally more stable carbides than cementite. Assuming proper heattreatment, the properties of a tool steel depends on the which alloying elements are added and their respective concentrations....

  2. A review of degradation modes of low carbon steel in brine environments

    International Nuclear Information System (INIS)

    Natalie, C.A.

    1987-01-01

    A literature search was conducted to review information on degradation modes of low carbon steel in brine solutions. A computer search was used to obtain articles from 1970 to present while a manual search was conducted for articles published prior to 1970. The published articles and reports indicated that uniform corrosion occurred in sea water, geothermal brines and simulated repository brines. The uniform corrosion rate increased with decreasing pH, increasing oxygen contest of brine and increasing temperature. Pitting of low carbon steel in brine solutions was related to scale formation due to presences of sulfur and heavy metal ions or mill scale present prior to exposure. Low carbon steel did not appear to be susceptible to stress corrosion cracking, but data was limited. The presence of anaerobic bacteria greatly increased the rate of corrosion of low carbon steel as compared to sterile conditions. If sufficient hydrogen is present, low carbon steel could fail due to hydrogen embrittlement in brine solutions. However, this is an area where experimental work needs to be done under more specific conditions related to salt repositories. Corrosion fatigue and stray current corrosion require specific conditions to occur which can be avoided during waste storage and were there fore not addressed. Also, galvanic effects were not addressed as it will be possible to minimize galvanic effects by design. 226 refs., 4 tabs

  3. Photo-electrochemical Investigation of Radiation-Enhanced Galvanic Coupling and Hydrogen Permeation in TPBAR-related Materials

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, G. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-02

    Research conducted in FY17 used photo-electrochemical methods to investigate the potential for radiationenhanced galvanic coupling in tritium-producing burnable absorber rod (TPBAR) materials. Specifically, a laboratory electrochemical cell was coupled with UV light in order to perform electrochemical opencircuit voltage and galvanic current measurements, techniques that have been used successfully in previous studies to replicate galvanic processes in reactor settings. UV irradiation can mimic reactor-like behavior because, similar to both directly and indirectly ionizing radiation, UV photons with energy greater than the band gap of the material will generate free charge carriers (electrons and holes) and can substantially alter the passivating effect of metal oxides.

  4. Actions to ensure the power and utilities supplying during the start-up and regular operation of the TKCSA steel complex through island operation mode; Acoes para garantir o suprimento de energia eletrica e utilidades durante a fase de start up e de operacao regular do complexo siderurgico da TKCSA (Thyssenkrupp - Companhia Siderurgica do Atlantico) atraves do modo de operacao em ilha

    Energy Technology Data Exchange (ETDEWEB)

    Vianna, Bernardo Matoso T.; Viana, Claudio Sobreira; Vaz, Daniel; Cesario, Fabricio; Pereira, Jose Antonio; Gimenez, Marcus Vinicius O.; Pascotto, Ricardo; Freitas Neto, Roberto Soares; Riederer, Werner [ThyssenKrupp Companhia Siderurgica do Atlantico (TKCSA), Rio de Janeiro, RJ (Brazil)

    2011-12-21

    At TKCSA, the energy and media distribution has an important function in the production processes. The electrical department is responsible for the power system operation, ensuring the receiving, transformation and supplying of this media for the regular and stable operation of the electrical equipment of the steel processes, and another important assignment of the electrical power sector is to guarantee the continuous power supply for the complex, even in case of interruption caused by the external grid, since the blast furnace, steel making and continuous casting cannot be interrupted abruptly. This continuous supply of energy is guaranteed by the Island Operation Mode (IOM), which always aims to ensure the supply of electricity from the Power Plant for the blowers, technical gases distribution system, fuel gases, steam and internal distribution of electricity and industrial water for the steel mill complex. During the complex start up and the regular operation phases, these two distribution systems (electricity and media) work interconnected and are kept in operation by the IOM, being guaranteed by the permanent operation of the electrical power generation system of Power Plant. This work presents how this concept was developed, tested and implemented at TKCSA. (author)

  5. Grain Refinement of Low Carbon Martensitic Steel by Heat Treatment

    OpenAIRE

    N. V. Kolebina; V. L. Danilov; S. Frechinet

    2015-01-01

    The low-carbon steels have good corrosion and technological properties. Hot deformation is the main operation in manufacturing the parts from these steels. So one of the important properties of the material is a property of plasticity. The grain size significantly influences on the ductility properties of steel. The grain size of steel depends on the chemical composition of the crystallization process, heat treatment, and steel machining. There are plenty methods to have grain refinement. How...

  6. The industrial ecology of steel

    Energy Technology Data Exchange (ETDEWEB)

    Considine, Timothy J.; Jablonowski, Christopher; Considine, Donita M.M.; Rao, Prasad G.

    2001-03-26

    This study performs an integrated assessment of new technology adoption in the steel industry. New coke, iron, and steel production technologies are discussed, and their economic and environmental characteristics are compared. Based upon detailed plant level data on cost and physical input-output relations by process, this study develops a simple mathematical optimization model of steel process choice. This model is then expanded to a life cycle context, accounting for environmental emissions generated during the production and transportation of energy and material inputs into steelmaking. This life-cycle optimization model provides a basis for evaluating the environmental impacts of existing and new iron and steel technologies. Five different plant configurations are examined, from conventional integrated steel production to completely scrap-based operations. Two cost criteria are used to evaluate technology choice: private and social cost, with the latter including the environmental damages associated with emissions. While scrap-based technologies clearly generate lower emissions in mass terms, their emissions of sulfur dioxide and nitrogen oxides are significantly higher. Using conventional damage cost estimates reported in the literature suggests that the social costs associated with scrap-based steel production are slightly higher than with integrated steel production. This suggests that adopting a life-cycle viewpoint can substantially affect environmental assessment of new technologies. Finally, this study also examines the impacts of carbon taxes on steel production costs and technology choice.

  7. Evaluation criteria of structural steel reliability

    International Nuclear Information System (INIS)

    Zav'yalov, A.S.

    1980-01-01

    Different low-carbon and medium-carbon structural steels are investigated. It is stated that steel reliability evaluation criteria depend on the fracture mode, steel suffering from the brittle fracture under the influence of the stresses (despite their great variety) arising in articles during the production and operation. Fibrous steel fracture at the given temperature and article thickness says about its high ductility and toughness and brittle fractures are impossible. Brittle fractures take place in case of a crystalline and mixed fracture with a predominant crystalline component. Evaluation methods of article and sample steel structural strength differing greatly from real articles in a thickness (diameter) or used at temperatures higher than possible operation temperatures cannot be reliability evaluation criteria because at a great thickness (diameter) and lower operation temperatures steel fracture and its strain mode can change resulting in a sharp reliability degradation

  8. Friction stir scribe welding technique for dissimilar joining of aluminium and galvanised steel

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tianhao [Center for Friction Stir Processing, Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA; Sidhar, Harpreet [Center for Friction Stir Processing, Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA; Mishra, Rajiv S. [Center for Friction Stir Processing, Department of Materials Science and Engineering, University of North Texas, Denton, TX, USA; Hovanski, Yuri [Pacific Northwest National Laboratory, Energy Materials and Manufacturing, Richland, WA, USA; Upadhyay, Piyush [Pacific Northwest National Laboratory, Energy Materials and Manufacturing, Richland, WA, USA; Carlson, Blair [General Motors Technical Center, Warren, MI, USA

    2017-10-04

    Friction stir scribe technology, a derivative of friction stir welding, was applied for the dissimilar lap welding of an aluminum alloy and galvanized mild steel sheets. During the process, the rotating tool with a cobalt steel scribe first penetrated the top material — aluminum — and then the scribe cut the bottom material — steel. The steel was displaced into the upper material to produce a characteristic hook feature. Lap welds were shear tested, and their fracture paths were studied. Welding parameters affected the welding features including hook height, which turned out to be highly related to fracture position. Therefore, in this paper, the relationships among welding parameters, hook height, joint strength and fracture position are presented. In addition, influence of zinc coating on joint strength was also studied. Keywords: friction stir scribe technology; dissimilar material welding; zinc coating; hook height; joint strength; fracture position

  9. Study of reactions between nuclear fuel and cladding (316 stainless steel) in reactors. Influence of oxygen

    International Nuclear Information System (INIS)

    Otter, Monique.

    1980-12-01

    We have studied oxidation of 316 steel in close contact with oxides (Usub(0,74)Pusub(0,26)O 2 or UO 2 ), the stoichiometry of oxygen ranging from 2.00 to 2.5. Experiments are carried out either in a closed isothermal system or in an opened isothermal system with a fixed oxygen potential of uranium oxide. We have realized a potentiostatic device using a solid state electrotyte galvanic cell. In a closed system, the sensitized austenitic steel shows intergranular and volume oxidation probably enhanced by migration of steel components towards the fuel. Evidence of the usefulness of passivation have been obtained. We conclude that in a fast reactor sensitized cladding steel is oxydized by the constant potential of oxygen of UPuO 2 . Deposits observed in fuel can be explain by evaporation and cyclic transport phenomena that can be differents from VAN-ARKEL mechanism taking place through fission products [fr

  10. Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

    International Nuclear Information System (INIS)

    Fernandes, Kirlene Salgado; Alvarenga, Evandro de Azevedo; Lins, Vanessa de Freitas Cunha

    2011-01-01

    Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electro painting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are identified using the Fourier transform infrared spectroscopy (FTIR). (author)

  11. Inertization of heavy metals present in galvanic sludge by DC thermal plasma.

    Science.gov (United States)

    Leal Vieira Cubas, Anelise; de Medeiros Machado, Marília; de Medeiros Machado, Marina; Gross, Frederico; Magnago, Rachel Faverzani; Moecke, Elisa Helena Siegel; Gonçalvez de Souza, Ivan

    2014-01-01

    Galvanic sludge results from the treatment of effluents generated by the industrial metal surface treatment of industrial material, which consists in the deposition of a metal on a surface or a metal surface attack, for example, electrodeposition of conductors (metals) and non conductive, phosphate, anodizing, oxidation and/or printed circuit. The treatment proposed here is exposure of the galvanic sludge to the high temperatures provided by thermal plasma, a process which aims to vitrify the galvanic sludge and render metals (iron, zinc, and chromium) inert. Two different plasma reactors were assembled: with a DC transferred arc plasma torch and with a DC nontransferred arc plasma torch. In this way it was possible to verify which reactor was more efficient in the inertization of the metals and also to investigate whether the addition of quartzite sand to the sludge influences the vitrification of the material. Quantification of water content and density of the galvanic raw sludge were performed, as well as analyzes of total organic carbon (TOC) and identify the elements that make up the raw sludge through spectroscopy X-ray fluorescence (XRF). The chemical composition and the form of the pyrolyzed and vitrified sludge were analyzed by scanning electron microscopy with energy-dispersive X-ray spectrometer (SEM-EDS) analysis, which it is a analysis that shows the chemical of the sample surface. The inertization of the sludge was verified in leaching tests, where the leachate was analyzed by flame atomic absorption spectroscopy (FAAS). The results of water content and density were 64.35% and 2.994 g.cm(-3), respectively. The TOC analysis determined 1.73% of C in the sample of galvanic raw sludge, and XRF analysis determined the most stable elements in the sample, and showed the highest peaks (higher stability) were Fe, Zn, and Cr. The efficiency of the sludge inertization was 100% for chromium, 99% for zinc, and 100% for iron. The results also showed that the most

  12. Study of localized corrosion of 304 stainless steel under chloride solution droplets using the wire beam electrode

    International Nuclear Information System (INIS)

    Wang Yanhua; Wang Wei; Liu Yuanyuan; Zhong Lian; Wang Jia

    2011-01-01

    Highlights: → The galvanic current distributions of localized corrosion of stainless steel under NaCl droplet were studied. → Serious corrosion sites were preferentially located near the three-phase boundary (TPB) zone. → Stainless steel suffered more severe localized corrosion with the increase of the size of droplets. - Abstract: Localized corrosion of 304 stainless steel under droplets of 1 M sodium chloride solution was investigated by the wire beam electrode (WBE) method. It was found that the current distributions were heterogeneous with isolated anodic current peaks mostly located near the edge of the droplet. During the corrosion process, the stainless steel WBE exhibited the stochastic characteristics with the disappearance of some anodic sites. In addition, stainless steel suffered more serious localized corrosion with the increase of the droplet size. The increase of the cathodic area and the three-phase boundary (TPB) length was believed to be the reason.

  13. Effect of a Sulphate Transient on the EAC Crack Growth Behaviour of Low-Alloy RPV Steels under Simulated BWR Operating Conditions (CASTOC WP 3, PSI Test 1)

    International Nuclear Information System (INIS)

    Ritter, S.; Seifert, H. P.

    2002-03-01

    Within the CASTOC-project (5th EU FW programme), the environmentally-assisted crack (EAC) growth behaviour of low-alloy reactor pressure vessel (RPV) steels is experimentally investigated under simulated transient and steady-state boiling water reactor (BWR) power operation conditions by six European laboratories. Within WP 3 of this project, the Paul Scherrer Institut (PSI) investigates the effect of water chemistry transients on the EAC crack growth behaviour under periodical partial unloading (PPU) conditions. The present report is a summary of the first PSI test of WP 3 with a Na 2 SO 4 transient. In the first part of the report, the theoretical background on crack growth mechanisms, crack chemistry, mass transport and water chemistry transients as well as a brief literature survey on other water chemistry transient investigations is given. Furthermore, the experimental equipment and test procedure is presented, followed by a summary of the results of PSI test 1 of WP 3. Finally the results are discussed in detail and compared to literature data. In the first part of the experiment, an actively growing EAC crack was generated by PPU in oxygenated high-temperature, high-purity water (T = 288 o C, DO = 8 ppm, SO 4 2- 4 2- = 368 ppb) of the applied sulphate transient conservatively covered all sulphate transients, which might occur in BWR/normal water chemistry (NWC) practice. After the transient, outlet conductivity was lowered from ca. 1 μS/cm to less than 0.15 μS/cm within 2.6 h by a 'two-loop technique'. No accelerating effect of the sulphate transient on the EAC crack growth of both tested fracture mechanics specimens under highly oxidising BWR/NWC conditions was observed, making it impossible to deterrnine incubation or delay times. The EAC crack growth rates (CGR) before, during and after the sulphate transient were in the range of the 'low-sulphur SCC CGR' of the GE-model. This observation was attributed to 'high-sulphur' crack chemistry conditions

  14. Effect of a Sulphate Transient on the EAC Crack Growth Behaviour of Low-Alloy RPV Steels under Simulated BWR Operating Conditions (CASTOC WP 3, PSI Test 1)

    Energy Technology Data Exchange (ETDEWEB)

    Ritter, S.; Seifert, H. P

    2002-03-01

    Within the CASTOC-project (5th EU FW programme), the environmentally-assisted crack (EAC) growth behaviour of low-alloy reactor pressure vessel (RPV) steels is experimentally investigated under simulated transient and steady-state boiling water reactor (BWR) power operation conditions by six European laboratories. Within WP 3 of this project, the Paul Scherrer Institut (PSI) investigates the effect of water chemistry transients on the EAC crack growth behaviour under periodical partial unloading (PPU) conditions. The present report is a summary of the first PSI test of WP 3 with a Na{sub 2}SO{sub 4} transient. In the first part of the report, the theoretical background on crack growth mechanisms, crack chemistry, mass transport and water chemistry transients as well as a brief literature survey on other water chemistry transient investigations is given. Furthermore, the experimental equipment and test procedure is presented, followed by a summary of the results of PSI test 1 of WP 3. Finally the results are discussed in detail and compared to literature data. In the first part of the experiment, an actively growing EAC crack was generated by PPU in oxygenated high-temperature, high-purity water (T = 288 {sup o}C, DO = 8 ppm, SO{sub 4}{sup 2-} < 0.6 ppb). Then a sulphate transient was applied. The duration ({approx} 300 h) and the amount of sulphate (SO{sub 4}{sup 2-} = 368 ppb) of the applied sulphate transient conservatively covered all sulphate transients, which might occur in BWR/normal water chemistry (NWC) practice. After the transient, outlet conductivity was lowered from ca. 1 {mu}S/cm to less than 0.15 {mu}S/cm within 2.6 h by a 'two-loop technique'. No accelerating effect of the sulphate transient on the EAC crack growth of both tested fracture mechanics specimens under highly oxidising BWR/NWC conditions was observed, making it impossible to deterrnine incubation or delay times. The EAC crack growth rates (CGR) before, during and after the

  15. Optimization of resistance spot welding parameters for microalloyed steel sheets

    Science.gov (United States)

    Viňáš, Ján; Kaščák, Ľuboš; Greš, Miroslav

    2016-11-01

    The paper presents the results of resistance spot welding of hot-dip galvanized microalloyed steel sheets used in car body production. The spot welds were made with various welding currents and welding time values, but with a constant pressing force of welding electrodes. The welding current and welding time are the dominant characteristics in spot welding that affect the quality of spot welds, as well as their dimensions and load-bearing capacity. The load-bearing capacity of welded joints was evaluated by tensile test according to STN 05 1122 standard and dimensions and inner defects were evaluated by metallographic analysis by light optical microscope. Thewelding parameters of investigated microalloyed steel sheets were optimized for resistance spot welding on the pneumatic welding machine BPK 20.

  16. Aircraft Steels

    Science.gov (United States)

    2009-02-19

    70 mm (0.4 x 0.4 x 2.8 in.) in L orientation with a Charpy notch at the mid-length for SCC test under four-point bending (ASTM F 1624- 95) TESTS ...MAXIMUM STRESS INTENSITY, Kmax, IN HIGH STRENGTH STEELS For the fatigue test in 3.5% NaCl solution, the FCG per cycle, da/dN, is converted to the...NAWCADPAX/TR-2009/12 AIRCRAFT STEELS by E. U. Lee R. Taylor C. Lei H. C. Sanders 19 February 2009

  17. Large-scale synthesis of Tellurium nanostructures via galvanic displacement of metals

    Science.gov (United States)

    Kok, Kuan-Ying; Choo, Thye-Foo; Ubaidah Saidin, Nur; Rahman, Che Zuraini Che Ab

    2018-01-01

    Tellurium (Te) is an attractive semiconductor material for a wide range of applications in various functional devices including, radiation dosimeters, optical storage materials, thermoelectric or piezoelectric generators. In this work, large scale synthesis of tellurium (Te) nanostructures have been successfully carried out in different concentrations of aqueous solutions containing TeO2 and NaOH, by galvanic displacements of Zn and Al which served as the sacrificial materials. Galvanic displacement process is cost-effective and it requires no template or surfactant for the synthesis of nanostructures. By varying the concentrations of TeO2 and NaOH, etching temperatures and etching times, Te nanostructures of various forms of nanostructures were successfully obtained, ranging from one-dimensional needles and rod-like structures to more complex hierarchical structures. Microscopy examinations on the nanostructures obtained have shown that both the diameters and lengths of the Te nanostructures increased with increasing etching temperature and etching time.

  18. [What is the future for the galvanic industry in Italy and Europe].

    Science.gov (United States)

    Cavallotti, P L

    2012-01-01

    A number of European directives and burocratic constraints give difficulties to the galvanic Italian industries: The situation of the Galvanic industry in Italy is examined, with special care about the innovation perspectives needed to maintain an important role for the Italian surface treatment processes in Italy. Alternatives are already present for zinc cyanic alkaline plating and for the passivation with chromates of zinc. Difficult instead is the substitution of bright nickel and of electroless autocatalytic nickel An important process is Plating On Plastics POP and on other non conducting materials with electroless nickel The substitution of colloidal Palladium for surface activation is proposed. New innovative processes are proposed, regarding composite depositions with powders of micron or nano size, pulsed current deposition and deposition of layers with structure controlled at nanometric level. A strict cooperation among Research centres, Universities and Industries can start the renewal of a production of fundamental importance for the Italian future.

  19. A Facile Fabrication of Silver-Coated Copper Nanowires by Galvanic Replacement

    Directory of Open Access Journals (Sweden)

    Xin He

    2016-01-01

    Full Text Available We demonstrated a general strategy to fabricate silver-coated copper nanowires by a galvanic replacement, which is guided by the chemical principle that metal ions (silver ions with a relatively high reduction potential can galvanically etch nanostructure made from a less metal (copper. Well-dispersed and high-yielded copper nanowires were initially synthesized and then introduced into silver-ammonia solution for the growth of silver nanocrystals on the nanowire surfaces under vigorous oscillation. The results of X-ray diffraction, scanning electron microscope, and transmission electron microscope revealed that the silver nanocrystals were uniformly distributed on the copper nanowire surfaces to form Cu-Ag heterostructures. The concentration of silver-ammonia solution and the time of replacement reaction determine the size and density of the silver nanocrystals. Our investigation might pave the way to the synthesis of other bimetallic nanostructures via a facile, fast, and economical route.

  20. The galvanic nature of synapse and the physicochemical aspects of nerve action.

    Science.gov (United States)

    Ghouri, M S; Shibata, S

    1984-04-01

    All electrode reactions are either electrochemical oxidation or electrochemical reduction reactions and therefore membrane potentials are produced by redox reactions. Postsynaptic potentials are the result of spontaneous galvanic electrochemical changes produced by neurotransmitters. Action potentials denote microelectrolysis along the axon length. Threshold is proportional to charge and the higher the threshold the greater the potential energy. Resting membrane potential is thermodynamically controlled whereas action potential is kinetically controlled phenomenon.

  1. Substrate decomposition in galvanic displacement reaction: Contrast between gold and silver nanoparticle formation

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Tapas; Satpati, Biswarup, E-mail: biswarup.satpati@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata-700 064 (India); Kabiraj, D. [Inter-University Accelerator Centre, Aruna Asaf Ali Marg, New Delhi-110067 (India)

    2015-06-24

    We have investigated substrate decomposition during formation of silver and gold nanoparticles in galvanic displacement reaction on germanium surfaces. Silver and gold nanoparticles were synthesized by electroless deposition on sputter coated germanium thin film (∼ 200 nm) grown initially on silicon substrate. The nanoparticles formation and the substrate corrosion were studied using scanning transmission electron microscopy (STEM) and the energy dispersive X-ray (EDX) spectroscopy.

  2. Measurement and analysis of channel attenuation characteristics for an implantable galvanic coupling human-body communication.

    Science.gov (United States)

    Zhang, Shuang; Pun, Sio Hang; Mak, Peng Un; Qin, Yu-Ping; Liu, Yi-He; Vai, Mang I

    2016-11-14

    In this study, an experiment was designed to verify the low power consumption of galvanic coupling human-body communication. A silver electrode (silver content: 99%) is placed in a pig leg and a sine wave signal with the power of 0 dBm is input. Compared with radio frequency communication and antenna transmission communication, attenuation is reduced by approximately 10 to 15 dB, so channel characteristics are highly improved.

  3. Intracavity OptoGalvanic Spectroscopy not suitable for ambient level radiocarbon detection.

    Science.gov (United States)

    Paul, Dipayan; Meijer, Harro A J

    2015-09-01

    IntraCavity OptoGalvanic Spectroscopy as a radiocarbon detection technique was first reported by the Murnick group at Rutgers University, Newark, NJ, in 2008. This technique for radiocarbon detection was presented with tremendous potentials for applications in various fields of research. Significantly cheaper, this technique was portrayed as a possible complementary technique to the more expensive and complex accelerator mass spectrometry. Several groups around the world started developing this technique for various radiocarbon related applications. The IntraCavity OptoGalvanic Spectroscopy setup at the University of Groningen was constructed in 2012 in close collaboration with the Murnick group for exploring possible applications in the fields of radiocarbon dating and atmospheric monitoring. In this paper we describe a systematic evaluation of the IntraCavity OptoGalvanic Spectroscopy setup at Groningen for radiocarbon detection. Since the IntraCavity OptoGalvanic Spectroscopy setup was strictly planned for dating and atmospheric monitoring purposes, all the initial experiments were performed with CO2 samples containing contemporary levels and highly depleted levels of radiocarbon. Because of recurring failures in differentiating the two CO2 samples, with the radiocarbon concentration 3 orders of magnitude apart, CO2 samples containing elevated levels of radiocarbon were prepared in-house and experimented with. All results obtained thus far at Groningen are in sharp contrast to the results published by the Murnick group and rather support the results put forward by the Salehpour group at Uppsala University. From our extensive test work, we must conclude that the method is unsuited for ambient level radiocarbon measurements, and even highly enriched CO2 samples yield insignificant signal.

  4. Systems and methods for bi-directional energy delivery with galvanic isolation

    Science.gov (United States)

    Kajouke, Lateef A.

    2013-06-18

    Systems and methods are provided for bi-directional energy delivery. A charging system comprises a first bi-directional conversion module, a second bi-directional conversion module, and an isolation module coupled between the first bi-directional conversion module and the second bi-directional conversion module. The isolation module provides galvanic isolation between the first bi-directional conversion module and the second bi-directional conversion module.

  5. Japan steel mill perspective

    Energy Technology Data Exchange (ETDEWEB)

    Murase, K. [Kobe Steel Ltd., Tokyo (Japan)

    2004-07-01

    The international and Japan's steel industry, the coking coal market, and Japan's expectations from Canada's coal industry are discussed. Japan's steel mills are operating at full capacity. Crude steel production for the first half of 2004 was 55.8 million tons. The steel mills are profitable, but costs are high, and there are difficulties with procuring raw materials. Japan is trying to enhance the quality of coke, in order to achieve higher productivity in the production of pig iron. Economic growth is rising disproportionately in the BRICs (Brazil, Russia, India, and China), with a large increase in coking coal demand from China. On the supply side, there are several projects underway in Australia and Canada to increase production. These include new developments by Elk Valley Coal Corporation, Grande Cache Coal, Western Canadian Coal, and Northern Energy and Mining in Canada. The Elga Mine in the far eastern part of Russia is under development. But the market is expected to remain tight for some time. Japan envisions Canadian coal producers will provide a stable coal supply, expansion of production and infrastructure capabilities, and stabilization of price. 16 slides/overheads are included.

  6. Cr(VI) reduction in wastewater using a bimetallic galvanic reactor

    International Nuclear Information System (INIS)

    Lugo-Lugo, Violeta; Barrera-Diaz, Carlos; Bilyeu, Bryan; Balderas-Hernandez, Patricia; Urena-Nunez, Fernando; Sanchez-Mendieta, Victor

    2010-01-01

    The electrochemical reduction of Cr(VI)-Cr(III) in wastewater by iron and copper-iron bimetallic plates was evaluated and optimized. Iron has been used as a reducing agent, but in this work a copper-iron galvanic system in the form of bimetallic plates is applied to reducing hexavalent chromium. The optimal pH (2) and ratio of copper to iron surface areas (3.5:1) were determined in batch studies, achieving a 100% reduction in about 25 min. The Cr(VI) reduction kinetics for the bimetallic system fit a first order mechanism with a correlation of 0.9935. Thermodynamic analysis shows that the Cr(VI) reduction is possible at any pH value. However, at pH values above 3.0 for iron and 5.5 for chromium insoluble species appear, indicating that the reaction will be hindered. Continuous column studies indicate that the bimetallic copper-iron galvanic system has a reduction capacity of 9.5890 mg Cr(VI) cm -2 iron, whereas iron alone only has a capacity of 0.1269 mg Cr(VI) cm -2 . The bimetallic copper-iron galvanic system is much more effective in reducing hexavalent chromium than iron alone. The exhausted plates were analyzed by SEM, EDS, and XRD to determine the mechanism and the surface effects, especially surface fouling.

  7. Galvanic Corrosion of Lead by Iron (Oxyhydr)Oxides: Potential Impacts on Drinking Water Quality.

    Science.gov (United States)

    Trueman, Benjamin F; Sweet, Gregory A; Harding, Matthew D; Estabrook, Hayden; Bishop, D Paul; Gagnon, Graham A

    2017-06-20

    Lead exposure via drinking water remains a significant public health risk; this study explored the potential effects of upstream iron corrosion on lead mobility in water distribution systems. Specifically, galvanic corrosion of lead by iron (oxyhydr)oxides was investigated. Coupling an iron mineral cathode with metallic lead in a galvanic cell increased lead release by 531 μg L -1 on average-a 9-fold increase over uniform corrosion in the absence of iron. Cathodes were composed of spark plasma sintered Fe 3 O 4 or α-Fe 2 O 3 or field-extracted Fe 3 O 4 and α-FeOOH. Orthophosphate immobilized oxidized lead as insoluble hydroxypyromorphite, while humic acid enhanced lead mobility. Addition of a humic isolate increased lead release due to uniform corrosion by 81 μg L -1 and-upon coupling lead to a mineral cathode-release due to galvanic corrosion by 990 μg L -1 . Elevated lead in the presence of humic acid appeared to be driven by complexation, with 208 Pb and UV 254 size-exclusion chromatograms exhibiting strong correlation under these conditions (R 2 average = 0.87). A significant iron corrosion effect was consistent with field data: lead levels after lead service line replacement were greater by factors of 2.3-4.7 at sites supplied by unlined cast iron distribution mains compared with the alternative, lined ductile iron.

  8. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    . Developing a Hegelian inspired historical-sociological approach this paper however argues that national and transnational societies emerged simultaneously and in a co-evolutionary and mutually supportive fashion. In most European settings national societies did not become the central horizon of individuals...... of the European steel industry....

  9. Hegelian Steel

    DEFF Research Database (Denmark)

    Kjær, Poul F.

    2015-01-01

    Even in our globalized world the notion of national economies remain incredibly strong, just as a considerable part of the literature on transnational governance and globalization continue to rely on a zero-sum perspective concerning the relationship between the national and the transnational. De...... of the European steel industry....

  10. Very High Frequency Galvanic Isolated Offline Power Supply

    DEFF Research Database (Denmark)

    Pedersen, Jeppe Arnsdorf

    During the last decades many researchers have turned their attention to raising the operation frequency of power converters to the very high frequency (VHF) range going from 30 MHz to 300 MHz. Increasing the operating frequency of a power converter leads to smaller energy storing components...... to eliminate the switching losses. The topologies used, are inspired by radio frequency amplifiers, which are used to generate high fre-quency current for an antenna. In VHF converters this antenna is replaced by a rectifier to generate a DC voltage. Driving these type of converters can be a challenge as hard...... inverters with a single combined rectifier. The converter designed to deliver 9 W to a 60 V LED load and is achieving an efficiency of 89.4% and a power density of 2.14 W3 . The development of this converter proof that offline VHF converter can be implemented with high efficiencies even for low power applications...

  11. 49 CFR 192.371 - Service lines: Steel.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Service lines: Steel. 192.371 Section 192.371 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... § 192.371 Service lines: Steel. Each steel service line to be operated at less than 100 p.s.i. (689 kPa...

  12. Recent advances in Ti and Nb explosion welding with stainless steel for 2K operating (ILC Program)- To the proceedings of LCWS11

    OpenAIRE

    Sabirov, B.; Budagov, J.; Sissakian, A.; Shirkov, G.; Taran, Yu.; Trubnikov, G.; Dhanarai, N.; Foley, M.; Harms, E.; Mitchell, D.; Nagaitsev, S.; Soyars, W.; Rybakov, V.; Samarokov, Yu.; Zhigalov, V.

    2012-01-01

    The world first samples 0f Ti+SS and Nb+SS joints were manufactured by an explosion welding technology demonstrating a high mechanic properties and leak absence at 4.6 x 10^{-9} atm-cc/sec. Residual stresses in bimetallic joints resulting from explosion welding measured by neutron diffraction method are quite high (~1000 MPa). Thermal tempering of explosion welded Ti+SS and Nb+SS specimens leads to complete relaxation of internal stresses in Ti,Nb and Stainless steel and makes the transition ...

  13. Phosphate coating on stainless steel 304 sensitized;Recubrimiento fosfatado sobre acero inoxidable 304 sensibilizado

    Energy Technology Data Exchange (ETDEWEB)

    Cruz V, J. P. [IPN, Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Altamira, Km. 14.5 Carretera Tampico-Puerto Industrial Altamira, 89600 Altamira, Tamaulipas (Mexico); Vite T, J. [ININ, Carretera Mexico-Toluca s/n, Ocoyoacac 52750, Estado de Mexico (Mexico); Castillo S, M.; Vite T, M., E-mail: jpcruz@ipn.m [IPN, Escuela Superior de Ingenieria Mecanica y Electrica, Seccion de Estudios de Posgrado e Investigacion, Unidad Profesional -Adolfo Lopez Mateos-, Zacatenco, 07738 Mexico, D. F. (Mexico)

    2009-07-01

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  14. Electrochemical Behaviour and Galvanic Effects of Titanium Implants Coupled to Metallic Suprastructures in Artificial Saliva

    Directory of Open Access Journals (Sweden)

    Ana Mellado-Valero

    2018-01-01

    Full Text Available The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c, one nickel-chromium-titanium alloy (NiCrTi, one gold-palladium alloy (Au, and one titanium alloy (Ti6Al4V, and the galvanic effect when they are coupled to titanium implants (TiG2. It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry in artificial saliva (AS, with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys.

  15. Electrochemical Behaviour and Galvanic Effects of Titanium Implants Coupled to Metallic Suprastructures in Artificial Saliva

    Science.gov (United States)

    Mellado-Valero, Ana; Igual Muñoz, Anna; Guiñón Pina, Virginia

    2018-01-01

    The aim of the present study is to analyze the electrochemical behavior of five different dental alloys: two cobalt-chromium alloys (CoCr and CoCr-c), one nickel-chromium-titanium alloy (NiCrTi), one gold-palladium alloy (Au), and one titanium alloy (Ti6Al4V), and the galvanic effect when they are coupled to titanium implants (TiG2). It was carried out by electrochemical techniques (open circuit measurements, potentiodynamic curves and Zero-Resistance Ammetry) in artificial saliva (AS), with and without fluorides in different acidic conditions. The studied alloys are spontaneously passivated, but NiCrTi alloy has a very narrow passive domain and losses its passivity in presence of fluorides, so is not considered as a good option for implant superstructures. Variations of pH from 6.5 to 3 in artificial saliva do not change the electrochemical behavior of Ti, Ti6Al4V, and CoCr alloys, and couples, but when the pH of the artificial saliva is below 3.5 and the fluoride content is 1000 ppm Ti and Ti6Al4V starts actively dissolving, and CoCr-c superstructures coupled to Ti show acceleration of corrosion due to galvanic effects. Thus, NiCrTi is not recommended for implant superstructures because of risk of Ni ion release to the body, and fluorides should be avoided in acidic media because Ti, Ti6Al4V, and CoCr-c superstructures show galvanic corrosion. The best combinations are Ti/Ti6Al4V and Ti/CoCr as alternative of noble gold alloys. PMID:29361767

  16. 76 FR 68407 - Galvanized Steel Wire From the People's Republic of China: Preliminary Determination of Sales at...

    Science.gov (United States)

    2011-11-04

    ..., 2011, correcting this language, and clarifying that the reference to ``30 feet'' was intended to... determined that Colombia, Indonesia, the Philippines, South Africa, Thailand, and Ukraine are countries whose..., the Department determined that Colombia, Indonesia, the Philippines, South Africa, Thailand, and...

  17. 76 FR 23548 - Galvanized Steel Wire From the People's Republic of China and Mexico: Initiation of Antidumping...

    Science.gov (United States)

    2011-04-27

    ... has long treated the PRC as a non-market economy (``NME'') country and this designation remains in... product for the PRC investigation is appropriately based on FOPs valued in a surrogate market-economy... the Uruguay Round Agreements Act (``URAA''), states that an allegation of sales below COP need not be...

  18. Evaluation of anodes for galvanic cathodic prevention of steel corrosion in prestressed concrete piles in marine environments in Virginia.

    Science.gov (United States)

    1999-07-01

    Many of the major highway crossings over coastal waters in the Hampton area of Virginia are supported by prestressed concrete piles, some of which are showing signs of reinforcement corrosion. Grout jacketing alone is an inadequate protection against...

  19. Research of physical and mechanical properties of electric steel, providing for the grate bars of the roasting and sintering machines improved operational stability

    Directory of Open Access Journals (Sweden)

    Олександр Давидович Учитель

    2016-07-01

    Full Text Available The grate bars of the conveyor roasting and sintering machines work in severe, aggressive dust and gaseous medium, under cyclic modes «heating-cooling», as well as under the load of iron ore agglomerates what results in bending stress in the body of the grate bar. Consequently, electric steel grate bar must be resistant to chemical and erosion processes, high cyclically changing temperature and have high mechanical properties. The paper discusses the conditions of the grate bars of conveyor roasting and sintering machines wear, depending on the adopted loading schemes. The materials to be processed can be loaded directly from the hopper (direct download or through the use of a feeder (drum-type feeder, roller, etc.. A simplified method to predict the grate bars surface wear on the strength of a number of assumptions has been developed: normal reaction of the pallet surface to the impact of the batch is assumed constant, equal to the maximum of its value when the pallet is in horizontal position; a layer of the batch moves as a rigid body; surface batch layer sliding velocity as related to the pallet surface is taken medium during the relative motion of the layer and equal to the linear velocity of the pallets; the side faces of the grate bars wear is related to related to the surface wear by linear dependence. The dependence of the wear on the friction forces and the steel wear resistance coefficient has been found out

  20. Physical characterization of steel and stainless steel metal powders

    International Nuclear Information System (INIS)

    Lavilla, A.O.; Lucchesi, C.G.; Sandin, O.O.

    1991-01-01

    A methodology has been developed for the physical characterization of steel powders (obtained by atomization) for later sintering and for the construction of porous sheets and filtrating tubes, capable of operating at temperatures between 600 deg C and 800 deg C in corrosive atmospheres. This methodology was based on the equipment and methods used for the physical characterization of uranium oxide powders. (Author) [es

  1. A Review of Galvanically Isolated Impedance-Source DC–DC Converters

    DEFF Research Database (Denmark)

    Chub, Andrii; Vinnikov, Dmitri; Blaabjerg, Frede

    2016-01-01

    Impedance-source converters, an emerging technology in electric energy conversion, overcome limitations of conventional solutions by the use of specific impedance-source networks. Focus of this paper is on the topologies of galvanically isolated impedance-source dc-dc converters. These converters...... isolated dc-dc converters according to the element that transfers energy from the input to the output: a transformer, a coupled inductor, or their combination. This classification reveals advantages and disadvantages, as well as a wide space for further research. This paper also outlines the most promising...

  2. Modeling and Characterization of cMUT-based Devices Applied to Galvanic Isolation

    Science.gov (United States)

    Heller, Jacques; Boulmé, Audren; Alquier, Daniel; Ngo, Sophie; Perroteau, Marie; Certon, Domnique

    This paper describes a new way of using cMUT technology: galvanic isolation for power electronics. These devices work like acoustic transformers, except that piezoelectricity is replaced by cMUT technology. Primary and secondary circuits are two cMUT-based transducers respectively layered on each side of a silicon substrate, through which the ultrasonic triggering signal is transmitted. A specific model based on a commercial finite element code was implemented to simulate these devices. A particular attention was paid on the modeling of the cMUT/substrate coupling which is a key feature for the intended application. First experimental results performed for model validation are presented here and discussed.

  3. [Use of magnetic therapy combined with galvanization and tissue electrophoresis in the treatment of trophic ulcers].

    Science.gov (United States)

    Alekseenko, A V; Gusak, V V; Stoliar, V F; Iftodiĭ, A G; Tarabanchuk, V V; Shcherban, N G; Naumets, A A

    1993-01-01

    The results of treatment of 86 patients with the use of magnetotherapy in combination with galvanization and intratissue electrophoresis are presented. To create an electric field, the "Potok-1" apparatus with a density of current equal to 0.05-0.1 mA/cm2 was employed. Simultaneously, the "MAG-30" apparatus for low-frequency magnetotherapy with induction of 30 mT and area of exposure of 20 cm2 was applied to a trophic ulcer site. The use of magnetogalvanotherapy in the complex of treatment of trophic ulcers of the lower extremities is recommended.

  4. Possibility of sorption purification of chromium comprising waste waters of galvanic production by inorganic ion exchangers

    International Nuclear Information System (INIS)

    Khaynakov, S.A.; Likov, E.P.; Bortun, A.I.; Belyukov, V.N.

    1986-01-01

    Present work is devoted to possibilities of sorption purification of chromium comprising waste waters of galvanic production by inorganic ion exchangers. Thus, the comparative study of sorption of chromium ions on anion exchanger A B-17 and on inorganic ion exchangers on the basis of hydrated titanium and zirconium dioxides in static and dynamic conditions is conducted. The influence of chromium ions concentration, solutions acidity (ph=1÷12) and presence of base electrolyte on sorption is studied. The state of chromium ions sorbed by inorganic ion exchangers is studied by means of infrared spectroscopy and spectroscopy. It is defined that inorganic sorbents could be used for chromium extraction from different solutions.

  5. The Feasibility of Using a Galvanic Cell Array for Corrosion Detection and Solution Monitoring

    Science.gov (United States)

    Kolody, Mark; Calle, Luz-Marina; Zeitlin, Nancy P. (Technical Monitor)

    2003-01-01

    An initial investigation into the response of the individual galvanic couples was conducted using potentiodynamic polarization measurements of solutions under conditions of varying corrosivity. It is hypothesized that the differing electrodes may provide a means to further investigate the corrosive nature of the analyte through genetic algorithms and pattern recognition techniques. The robust design of the electrochemical sensor makes its utilization in space exploration particularly attractive. Since the electrodes are fired on a ceramic substrate at 900 C, they may be one of the most rugged sensors available for the anticipated usage.

  6. Less-Conventional Low-Consumption Galvanic Separated MOSFET-IGBT Gate Drive Supply

    Directory of Open Access Journals (Sweden)

    Jean Marie Vianney Bikorimana

    2017-01-01

    Full Text Available A simple half-bridge, galvanic separated power supply which can be short circuit proof is proposed for gate driver local supplies. The supply is made while hacking a common mode type filter as a transformer, as the transformer shows a good insulation, it has a very low parasitic capacitance between primary and secondary coils, and it is cost-effective. Very low standby losses were observed during lab experiments. This makes it compatible with energy efficient drives and solar inverters.

  7. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Petala, M., E-mail: petala@civil.auth.gr [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Tsiridis, V. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Mintsouli, I. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Pliatsikas, N. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Spanos, Th. [Department of Petroleum and Mechanical Engineering Sciences, Eastern Macedonia and Thrace Institute of Technology, Kavala, 65404 (Greece); Rebeyre, P. [ESA/ESTEC, P.O.Box 299, 2200 AG, Noordwijk (Netherlands); Darakas, E. [Department of Civil Engineering, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Patsalas, P.; Vourlias, G. [Department of Physics, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece); Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th. [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki, 54124 (Greece)

    2017-02-28

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  8. Silver deposition on stainless steel container surfaces in contact with disinfectant silver aqueous solutions

    International Nuclear Information System (INIS)

    Petala, M.; Tsiridis, V.; Mintsouli, I.; Pliatsikas, N.; Spanos, Th.; Rebeyre, P.; Darakas, E.; Patsalas, P.; Vourlias, G.; Kostoglou, M.; Sotiropoulos, S.; Karapantsios, Th.

    2017-01-01

    Highlights: • Silver is one of the biocides of water consumed in the International Space Station. • Ionic silver is depleted from potable water when in contact with stainless steel (SS). • SEM and XPS analysis reveal a uniform silver deposition over the SS surface. • Silver deposits in its metallic form, in line with a galvanic deposition mechanism. • Evidence is provided that Cr and/ or Ni oxide builds-up on SS surfaces. - Abstract: Silver is the preservative used on the Russian segment of the International Space Station (ISS) to prevent microbial proliferation within potable water supplies. Yet, in the frame of the European Automated Transfer Vehicle (ATV) missions to ISS, silver depletion from water has been detected during ground transportation of this water to launch site, thereby indicating a degradation of water quality. This study investigates the silver loss from water when in contact with stainless steel surfaces. Experiments are conducted with several types of stainless steel surfaces being exposed to water containing 10 or 0.5 mg/L silver ions. Results show that silver deposits on stainless steel surfaces even when a passivation layer protects the metallic surface. The highest protection to silver deposition is offered by acid passivated and electropolished SS 316L. SEM and XPS experiments were carried out at several locations of the sample area that was in contact with the Ag solution and found similar morphological (SEM) and compositional (sputter-etch XPS) results. The results reveal that silver deposits uniformly across the wetted surface to a thickness larger than 3 nm. Moreover, evidence is provided that silver deposits in its metallic form on all stainless steel surfaces, in line with a galvanic deposition mechanism. Combination of ICP-MS and XPS results suggests a mechanism for Ag deposition/reduction with simultaneous substrate oxidation resulting in oxide growth at the exposed stainless steel surface.

  9. How geostatistics can help you find lead and galvanized water service lines: The case of Flint, MI.

    Science.gov (United States)

    Goovaerts, Pierre

    2017-12-01

    In the aftermath of Flint drinking water crisis, most US cities have been scrambling to locate all lead service lines (LSLs) in their water supply systems. This information, which is most often inaccurate or lacking, is critical to assess compliance with the Lead and Copper Rule and to plan the replacement of lead and galvanized service lines (GSLs) as currently under way in Flint. This paper presents the first geospatial approach to predict the likelihood that a home has a LSL or GSL based on neighboring field data (i.e., house inspection) and secondary information (i.e., construction year and city records). The methodology is applied to the City of Flint where 3254 homes have been inspected by the Michigan Department of Environmental Quality to identify service line material. GSLs and LSLs were mostly observed in houses built prior to 1934 and during World War II, respectively. City records led to the over-identification of LSLs, likely because old records were not updated as these lines were being replaced. Indicator semivariograms indicated that both types of service line are spatially clustered with a range of 1.4km for LSLs and 2.8km for GSLs. This spatial autocorrelation was integrated with secondary data using residual indicator kriging to predict the probability of finding each type of material at the tax parcel level. Cross-validation analysis using Receiver Operating Characteristic (ROC) Curves demonstrated the greater accuracy of the kriging model relative to the current approach targeting houses built in the forties; in particular as more field data become available. Anticipated rates of false positives and percentages of detection were computed for different sampling strategies. This approach is flexible enough to accommodate additional sources of information, such as local code and regulatory changes, historical permit records, maintenance and operation records, or customer self-reporting. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Implementation of a galvanically isolated low-noise power supply board for multi-channel headstage preamplifiers.

    Science.gov (United States)

    Tóth, Attila; Máthé, Kálmán; Petykó, Zoltán; Szabó, Imre; Czurkó, András

    2008-06-15

    Custom made multi-channel headstage preamplifiers are traditionally powered by battery. By the use of an isolated unregulated DC/DC converter integrated circuit (DCP010512B from Texas Instruments Inc., TX, USA), here we describe the implementation of a galvanically isolated low-noise power supply board for multi-channel headstage preamplifiers. The implemented galvanically isolated power supply board provides the same quality noise free recording as the battery power supply. The non-isolated part of the power supply board is powered by standard 230 V AC/6 V DC wall mount adapter or USB cable. The described galvanically isolated power supply board can replace the batteries in preamplifier power supplies without any deterioration of the quality of recordings.

  11. A finite-element simulation of galvanic coupling intra-body communication based on the whole human body.

    Science.gov (United States)

    Song, Yong; Zhang, Kai; Hao, Qun; Hu, Lanxin; Wang, Jingwen; Shang, Fuzhou

    2012-10-09

    Simulation based on the finite-element (FE) method plays an important role in the investigation of intra-body communication (IBC). In this paper, a finite-element model of the whole body model used for the IBC simulation is proposed and verified, while the FE simulation of the galvanic coupling IBC with different signal transmission paths has been achieved. Firstly, a novel finite-element method for modeling the whole human body is proposed, and a FE model of the whole human body used for IBC simulation was developed. Secondly, the simulations of the galvanic coupling IBC with the different signal transmission paths were implemented. Finally, the feasibility of the proposed method was verified by using in vivo measurements within the frequency range of 10 kHz-5 MHz, whereby some important conclusions were deduced. Our results indicate that the proposed method will offer significant advantages in the investigation of the galvanic coupling intra-body communication.

  12. Galvanic Displacement of Gallium Arsenide Surface: A Simple and Low-Cost Method to Deposit Metal Nanoparticles and Films

    Directory of Open Access Journals (Sweden)

    Ngoc Duy Pham

    2014-01-01

    Full Text Available Herein, we report galvanic displacement of metal nanoparticles and films onto single-crystalline GaAs (100 substrates, a simple and cost-effective method to fabricate highly controlled metal/semiconductor interface. A time-resolved surface analysis of Au/GaAs system was conducted and microscopic mechanism of galvanic displacement was elucidated in detail. Quantitative temporal XPS measurements of the Au/GaAs interface showed that, initially, fast Au growth was slowed down as the deposition process proceeded. This was attributed to growing oxide layer blocking hole conduction and causing quenching of the deposition process. Addition of various inorganic acids, which function as oxide etchants, was found to enhance deposition rates by effectively removing surface oxide, with HF the most effective. Various precious metals, such as Pt and Ag, could be deposited onto GaAs through galvanic displacement, which demonstrates the versatility of the method.

  13. Cortisol, biochemical, and galvanic skin responses to music stimuli of different preference values by college students in biology and music.

    Science.gov (United States)

    VanderArk, S D; Ely, D

    1993-08-01

    The purpose of this study was to examine biochemical and galvanic skin responses to music stimuli. Specifically, 30 university biology and 30 music students' plasma levels of norepinephrine and cortisol and their galvanic skin responses were measured before and after listening to two different musical selections, one of which was preferred (liked) by the music students and not preferred (disliked) by the biology students. The music-listening sessions and the controlled silent sessions were done in an anechoic chamber. 30 biology majors and 30 music majors were in the experimental groups; 14 biology and 17 music majors comprised the control group. Analysis indicated that the cortisol levels and galvanic skin responses were significantly higher for the music majors than the biology majors. The data indicate that music majors listen more critically and analytically to music than biology majors, and cortisol levels are associated with this as increases in music majors and decreases in biology majors after the music.

  14. Development of nuclear grade stainless steels at KCSSL

    International Nuclear Information System (INIS)

    Balachandran, G.; Dhere, M.; Mahadik, A.; Hinge, N.M.; Balasubramanian, V.

    2011-01-01

    Kalyani Carpenter Special Steels Ltd is an alloy steel plant, where a variety of alloy steel grades are produced for automotive, defence, nuclear and aerospace applications. The plant has developed expertise in processing of several alloy steel grades of superior quality that meets stringent specifications. Primary steel is processed through a combination of electric arc furnace, ladle furnace and vacuum degassing where stringent control over dephosphorisation, desulphurization, deoxidation is effected to get a refined high quality steel. The molten steel is cast through continuous casting of slabs or ingot casting. In grades specific to nuclear application, the primary cast products are further subjected to electroslag remelting to achieve further freedom from inclusions and to achieve a favourable solidification grain structure, which ultimately improve the hot workability of the alloy steel. Appropriate choice of slag and operating parameters are needed for realising the required ingot quality. The present study would examine the processing and quality aspects of some important grades of steels used in nuclear industry namely ferritic 9Cr-1Mo steel, martensitic stainless steels 403, 410, precipitation hardenable 17-4 PH stainless steel and austenitic 321, 316LN stainless steel, which were made and supplied for applications to Indian nuclear industry. The expertise developed in processing the steels in terms of melting, heat treatment and their relationship to structural features and mechanical properties would be highlighted. (author)

  15. Precision machining of steel decahedrons

    Science.gov (United States)

    Abernathy, W. J.; Sealy, J. R.

    1972-01-01

    Production of highly accurate decahedron prisms from hardened stainless steel is discussed. Prism is used to check angular alignment of mounting pads of strapdown inertial guidance system. Accuracies obtainable using recommended process and details of operation are described. Photographic illustration of production device is included.

  16. Corrosion analysis of decommissioned carbon steel waste water tanks at Brookhaven National Laboratory

    International Nuclear Information System (INIS)

    Soo, P.; Roberts, T.C.

    1995-07-01

    A corrosion analysis was carried out on available sections of carbon steels taken from two decommissioned radioactive waste water tanks at Brookhaven National Laboratory. One of the 100,000 gallon tanks suffered from a pinhole failure in the wall which was subsequently patched. From the analysis it was shown that this leak, and two adjacent leaks were initiated by a discarded copper heating coil that had been dropped into the tank during service. The failure mechanism is postulated to have been galvanic attack at points of contact between the tank structure and the coil. Other leaks in the two tanks are also described in this report

  17. Electrochemical and crystallographic aspects of the corrosion of austenitic stainless steels in concentrated hot soda solutions

    International Nuclear Information System (INIS)

    Santarini, G.; Boos, J.Y.

    1976-01-01

    Some electrochemical and crystallographic aspects of stainless steel corrosion in concentrated hot soda are presented. Caustic cracking appears when the metallic surface presents an active behavior as immerged; the initial activity induces a selective dissolution of iron and chromium, and appearance of a pure nickel layer, which, by galvanic coupling, displaces the underlying surface potential towards a pseudo-passivity area; pseudo-passivity is due to the formation of a mixed oxide of the NaMO 2 type, which requires a revision of the thermodynamics bases of the alkaline corrosion interpretations. The crystallographic aspects of the mixed oxide growth enables a better understanding of the stress corrosion mechanisms [fr

  18. Silicate glasses obtained from fine silica powder modified with galvanic waste addition

    International Nuclear Information System (INIS)

    Silva, A.C.; Castanho, S.R.H. Mello

    2004-01-01

    This work presents a study of waste incorporation in silicate glass process based on the formulations of soda-lime glass compositions using two different industrial solid residues. Glass silicates were produced from the residue of silica powders retained in the filter sleeves of sanitary ceramic factories. An other waste also used as the starting material was the solid galvanic residue from metallurgical processes. Besides part of the silica contents was replaced by boron oxide to improve melting of the glasses and the behavior of both the formulations was analyzed. The temperatures for the fusion were selected based on the equilibria diagrams and the flux characteristics of the melting as a function of the glass compositions. Temperatures up to 1500 o C and annealing treatments were used. The composition and the structure of the glass specimens were studied using X-ray fluorescence and X-ray diffraction methods. The resistances of the glasses at environmental conditions by hydrolysis, acid and alkaline attack experiments were analyzed. Glasses with up to 40wt% of added galvanic solid waste and 28wt% of fine silica powder with a good chemical resistance were obtained

  19. A simple soft lithographic nanopatterning of gold on gallium arsenide via galvanic displacement.

    Science.gov (United States)

    Lim, Hyuneui; Noh, Jung-Hyun; Choi, Dae-Geun; Kim, Wan-Doo; Maboudian, Roya

    2010-08-01

    Nanoscale patterning of gold layers on GaAs substrate is demonstrated using a combination of soft lithographic molding and galvanic displacement deposition. First, an electroless deposition method has been developed to plate gold on GaAs with ease and cost-effectiveness. The electroless metallization process is performed by dipping the GaAs substrates into a gold salt solution without any reducing agents or additives. The deposition proceeds via galvanic displacement in which gold ions in the aqueous solution are reduced by electrons arising from the GaAs substrate itself. The deposition rate, surface morphology and adhesion property can be modulated by the plating parameters such as the choice of acids and the immersion time. Second, soft lithographic patterning of nanodots, nanorings, and nanolines are demonstrated on GaAs substrates with hard-polydimethylsiloxane (h-PDMS) mold and plasma etching. This method can be easily applied to the metallization and nanopatterning of gold on GaAs surfaces.

  20. Biosorption of chromium from electroplating and galvanizing industrial effluents under extreme conditions using Chlorella vulgaris

    Directory of Open Access Journals (Sweden)

    G. Sibi

    2016-07-01

    Full Text Available Hexavalent chromium [Cr(VI] is a toxic oxidized form and an important metal pollutant in the water bodies. Biosorption of chromium(VI offers a potential alternative to conventional metal removal methods. Dried biomass of Chlorella vulgaris was used as biosorbent for the removal of Cr(VI from electroplating and galvanizing industry effluents as a function of biosorbent dosage, contact time, pH, salinity and initial metal ion concentration. Batch experiments were conducted for biosorption and the optimum conditions were 1 g/L biomass, 4 h contact time, pH 2 and 2.893 mS/cm of electrical conductivity. The chromium biosorption was strictly pH dependent with a maximum Cr removal of 63.2 mg/L at pH 2. Highest Cr removal at a concentration of 81.3 mg/L was observed at Electrical conductivity (EC value of 2.893 mS/cm. A comparison of Langmuir and Freundlich isotherm models revealed that Freundlich isotherm model fitted the experimental data based on R2, qmax and standard error values. The results suggest that C. vulgaris biomass could be considered a promising low-cost biosorbent for the removal of Cr(VI from electroplating and galvanizing industry effluents. Keywords: Biosorption, Chlorella vulgaris, Microalgae, Hexavalent chromium

  1. Surface investigation and tribological mechanism of a sulfate-based lubricant deposited on zinc-coated steel sheets

    International Nuclear Information System (INIS)

    Timma, Christian; Lostak, Thomas; Janssen, Stella; Flock, Jörg; Mayer, Christian

    2016-01-01

    Highlights: • Skin-passed hot-dip galvanized (HDG-) steel sheets were coated with (NH 4 ) 2 SO 4 in a common roll-coating method. • A formation of (NH 4 ) 2 Zn(SO 4 ) * xH 2 O was observed and the reaction mainly occurred in the skin-passed areas of the surface. • Sulfate coated samples reveal a superior friction behaviour in oil-like conditions compared non-sulfated specimen. - Abstract: Phosphatation is a well-known technique to improve friction and wear behaviour of zinc coated steel, but has a variety of economic and ecologic limitations. In this study an alternative coating based on ammonium sulfate ((NH 4 ) 2 SO 4 ) is applied on skin-passed hot-dip galvanized steel sheets in order to investigate its surface chemical and tribological behaviour in a Pin-on-Disk Tribometer. Raman- and X-ray photoelectron spectroscopic results revealed a formation of ammonium zinc sulfate ((NH 4 ) 2 Zn(SO 4 ) 2 * xH 2 O) on the surface, which is primarily located in the skin-passed areas of the steel material. Sulfate coated samples exhibited a superior friction behaviour in Pin-on-Disk Tests using squalane as a model substance for oil-like lubricated conditions and a formation of a thin lubrication film is obtained in the wear track. Squalane acts as a carrier substance for ammonium zinc sulfate, leading to an effective lubrication film in the wear track.

  2. 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

  3. Electroencephalographic, Heart Rate, and Galvanic Skin Response Assessment for an Advertising Perception Study: Application to Antismoking Public Service Announcements.

    Science.gov (United States)

    Cartocci, Giulia; Caratù, Myriam; Modica, Enrica; Maglione, Anton Giulio; Rossi, Dario; Cherubino, Patrizia; Babiloni, Fabio

    2017-08-28

    The evaluation of advertising, products, and packaging is traditionally performed through methods based on self-reports and focus groups, but these approaches often appear poorly accurate in scientific terms. Neuroscience is increasingly applied to the investigation of the neurophysiological bases of the perception of and reaction to commercial stimuli to support traditional marketing methods. In this context, a particular sector or marketing is represented by public service announcements (PSAs). The objective of this protocol is to apply electroencephalography (EEG) and autonomic signal analysis to study responses to selected antismoking PSAs. Two EEG indices were employed: the frontal alpha band EEG asymmetry (the Approach Withdrawal (AW) index) and the frontal theta (effort index). Furthermore, the autonomic Emotional Index (EI) was calculated, as derived from the Galvanic Skin Response (GSR) and Heart Rate (HR) signals. The present protocol describes a series of operational and computational steps required to properly estimate, through the aforementioned indices, the emotional and cerebral reaction of a group of subjects towards a selected number of antismoking PSAs. In particular, a campaign characterized by a symbolic communication style (classified as "awarded" on the basis of the prizes received by specialized committees) obtained the highest approach values, as estimated by the AW index. A spot and an image belonging to the same PSA campaign based on the "fear arousing appeal" and with a narrative/experiential communication style (classified as "effective" on the basis of the economical/health-related improvements promoted) reported the lowest and highest effort values, respectively. This is probably due to the complexity of the storytelling (spot) and to the immediateness of the image (a lady who underwent a tracheotomy). Finally, the same "effective" campaign showed the highest EI values, possibly because of the empathy induced by the testimonial and the

  4. Plasma nitriding of steels

    CERN Document Server

    Aghajani, Hossein

    2017-01-01

    This book focuses on the effect of plasma nitriding on the properties of steels. Parameters of different grades of steels are considered, such as structural and constructional steels, stainless steels and tools steels. The reader will find within the text an introduction to nitriding treatment, the basis of plasma and its roll in nitriding. The authors also address the advantages and disadvantages of plasma nitriding in comparison with other nitriding methods. .

  5. Composite Coatings of Chromium and Nanodiamond Particles on Steel

    Directory of Open Access Journals (Sweden)

    Gidikova N.

    2017-12-01

    Full Text Available Chrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM are produced by detonation synthesis (NDDS. The composite coating (Cr+NDDS has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.

  6. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    International Nuclear Information System (INIS)

    Chartier, D.; Muzeau, B.; Stefan, L.; Sanchez-Canet, J.; Monguillon, C.

    2017-01-01

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  7. Synthesis of Hollow Gold-Silver Alloyed Nanoparticles: A "Galvanic Replacement" Experiment for Chemistry and Engineering Students

    Science.gov (United States)

    Jenkins, Samir V.; Gohman, Taylor D.; Miller, Emily K.; Chen, Jingyi

    2015-01-01

    The rapid academic and industrial development of nanotechnology has led to its implementation in laboratory teaching for undergraduate-level chemistry and engineering students. This laboratory experiment introduces the galvanic replacement reaction for synthesis of hollow metal nanoparticles and investigates the optical properties of these…

  8. Sensitivity of trunk variability and stability measures to balance impairments induced by galvanic vestibular stimulation during gait.

    NARCIS (Netherlands)

    van Schooten, K.S.; Sloot, L.H.; Bruijn, S.M.; Kingma, H; Meijer, O.G.; Pijnappels, M.A.G.M.; van Dieen, J.H.

    2011-01-01

    For targeted prevention of falls, it is necessary to identify individuals with balance impairments. To test the sensitivity of measures of variability, local stability and orbital stability of trunk kinematics to balance impairments during gait, we used galvanic vestibular stimulation (GVS) to

  9. Galvanic microparticles increase migration of human dermal fibroblasts in a wound-healing model via reactive oxygen species pathway.

    Science.gov (United States)

    Tandon, Nina; Cimetta, Elisa; Villasante, Aranzazu; Kupferstein, Nicolette; Southall, Michael D; Fassih, Ali; Xie, Junxia; Sun, Ying; Vunjak-Novakovic, Gordana

    2014-01-01

    Electrical signals have been implied in many biological mechanisms, including wound healing, which has been associated with transient electrical currents not present in intact skin. One method to generate electrical signals similar to those naturally occurring in wounds is by supplementation of galvanic particles dispersed in a cream or gel. We constructed a three-layered model of skin consisting of human dermal fibroblasts in hydrogel (mimic of dermis), a hydrogel barrier layer (mimic of epidermis) and galvanic microparticles in hydrogel (mimic of a cream containing galvanic particles applied to skin). Using this model, we investigated the effects of the properties and amounts of Cu/Zn galvanic particles on adult human dermal fibroblasts in terms of the speed of wound closing and gene expression. The collected data suggest that the effects on wound closing are due to the ROS-mediated enhancement of fibroblast migration, which is in turn mediated by the BMP/SMAD signaling pathway. These results imply that topical low-grade electric currents via microparticles could enhance wound healing. © 2013 Elsevier Inc. All rights reserved.

  10. Magnesium alloys and graphite wastes encapsulated in cementitious materials: Reduction of galvanic corrosion using alkali hydroxide activated blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Chartier, D., E-mail: david.chartier@cea.fr [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Muzeau, B. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France); Stefan, L. [AREVA NC/D& S - France/Technical Department, 1 place Jean Millier 92084 Paris La Défense (France); Sanchez-Canet, J. [Commissariat à l' Energie Atomique et aux Energies Alternatives, CEA, DEN, DTCD, SPDE, F-30207 Bagnols-sur-Cèze (France); Monguillon, C. [DEN-Service d’Etude du Comportement des Radionucléides (SECR), CEA, Université Paris-Saclay, F-91191, Gif-sur-Yvette (France)

    2017-03-15

    Highlights: • Embedded in cement, magnesium is corroded by residual water present in porosity of the matrix. • Corrosion is enhanced by galvanic phenomenon when magnesium is in contact with graphite. • Galvanic corrosion of magnesium in contact with graphite debris is shown to be severe with ordinary Portland cement. • Galvanic corrosion is significantly lowered in high alkali medium such as sodium hydroxide. • Sodium hydroxide activated blast furnace slag is a convenient binder to embed magnesium. - Abstract: Magnesium alloys and graphite from spent nuclear fuel have been stored together in La Hague plant. The packaging of these wastes is under consideration. These wastes could be mixed in a grout composed of industrially available cement (Portland, calcium aluminate…). Within the alkaline pore solution of these matrixes, magnesium alloys are imperfectly protected by a layer of Brucite resulting in a slow corrosion releasing hydrogen. As the production of this gas must be considered for the storage safety, and the quality of wasteform, it is important to select a cement matrix capable of lowering the corrosion kinetics. Many types of calcium based cements have been tested and most of them have caused strong hydrogen production when magnesium alloys and graphite are conditioned together because of galvanic corrosion. Exceptions are binders based on alkali hydroxide activated ground granulated blast furnace slag (BFS) which are presented in this article.

  11. Corrosion of steels in sour gas environments

    International Nuclear Information System (INIS)

    Twigg, R.J.

    1984-03-01

    This report presents a study on the effects of sour gas environments on steels. Emphasis is placed on alloys commonly used in the heavy water, sour gas and refining industries. In addition, 'high strength, low alloy' steels, known as 'oil country tubular goods', are included. Reference is made to the effects of hydrogen sulphide environments on austenitic steels and on certain specialty steels. Theories of hydrogen-related cracking mechanisms are outlined with emphasis placed on sulphide stress cracking and hydrogen induced cracking in carbon and low alloy steels. Methods of controlling sulphide stress cracking and hydrogen induced cracking are addressed separately. Case histories from the heavy water, refining, and sour gas industries are used to illustrate operating experience and failure mechanisms. Finally, recommendations, based largely on the author's industrial experience, are made with respect to quality assurance and inspection requirements for sour service components. Only published literature was surveyed. Abstracts were made of all references, reviewing the major sources in detail

  12. Galvanic corrosion of copper-cast iron couples in relation to the Swedish radioactive waste canister concept

    International Nuclear Information System (INIS)

    Smart, N.R.; Fennell, P.A.H.; Rance, A.P.; Werme, L.O.

    2004-01-01

    To ensure the safe encapsulation of spent nuclear fuel rods for geological disposal, SKB are considering using the Copper-Iron Canister, which consists of an outer copper canister and an inner cast iron container. The canister will be placed into boreholes in the bedrock of a geologic repository and surrounded by bentonite clay. In the unlikely event of the outer copper canister being breached, water could enter the annulus between the inner and outer canister and at points of contact between the two metals there would be a possibility of galvanic interactions. To study this effect, copper-cast iron galvanic couples were set up in a number of different environments representing possible conditions in the SKB repository. The tests investigated two artificial pore-waters and a bentonite slurry, under aerated and deaerated conditions, at 30 deg. C and 50 deg. C. The currents passing between the coupled electrodes and the potential of the couples were monitored for several months. In addition, some bimetallic crevice specimens based on the multi-crevice assembly (MCA) design were used to simulate the situation where the copper canister will be in direct contact with the cast iron inner vessel. The effect of growing an oxide film on the surface of the cast iron prior to coupling it with copper was also investigated. The electrochemical results are presented graphically in the form of electrode potentials and galvanic corrosion currents as a function of time. The galvanic currents in aerated conditions were much higher than in deaerated conditions. For example, at 30 deg. C, galvanic corrosion rates as low as 0.02 μm/year were observed for iron in groundwater after de-aeration, but of the order of 100 μm/year for the cast iron at 50 deg. C in the presence of oxygen. The galvanic currents were generally higher at 50 deg. C than at 30 deg. C. None of the MCA specimens exhibited any signs of crevice corrosion under deaerated conditions. It will be shown that in deaerated

  13. Diamondlike carbon coating as a galvanic corrosion barrier between dental implant abutments and nickel-chromium superstructures.

    Science.gov (United States)

    Ozkomur, Ahmet; Erbil, Mehmet; Akova, Tolga

    2013-01-01

    The objectives of this study were to evaluate the galvanic corrosion behavior between titanium and nickel-chromium (Ni-Cr) alloy, to investigate the effect of diamondlike carbon (DLC) coating over titanium on galvanic corrosion behavior between titanium and Ni-Cr alloy, and to evaluate the effect of DLC coating over titanium abutments on the fit and integrity of prosthetic assemblies by scanning electron microcopy (SEM). Five Ni-Cr and 10 titanium disks with a diameter of 5 mm and thickness of 3 mm were prepared. DLC coating was applied to five titanium disks. Electrode samples were prepared, and open circuit potential measurements, galvanic current measurements over platinum electrodes, and potentiodynamic polarization tests were carried out. For the SEM evaluation, 20 Ni-Cr alloy and 10 gold alloy superstructures were cast and prepared over 30 abutments. DLC coating was applied to 10 of the abutments. Following the fixation of prosthetic assemblies, the samples were embedded in acrylic resin and cross sectioned longitudinally. Internal fit evaluations were carried out through examination of the SEM images. Titanium showed more noble and electrochemically stable properties than Ni-Cr alloy. DLC coating over the cathode electrode served as an insulating film layer over the surface and prevented galvanic coupling. Results of the SEM evaluations indicated that the DLC-coated and titanium abutments showed no statistically significant difference in fit. Hence, no adverse effects on the adaptation of prosthetic components were found with the application of DLC coating over abutment surfaces. DLC coating might serve as a galvanic corrosion barrier between titanium abutments and Ni-Cr superstructures.

  14. Interfacial Microstructure and Properties of Steel/Aluminum Powder Additive

    Directory of Open Access Journals (Sweden)

    YUAN Jiang

    2017-09-01

    Full Text Available Based on first-principles density functional theory, the Fe/Al interface model of steel/aluminum laser welding was constructed by layer technique. The Fe/Al interface was studied by metal atom X (X=Sn, Sr, Zr, Ce, La.The results show that Sn, Sr and Ce preferentially displace the Al atoms at the Fe/Al interface, while La and Zr preferentially displace the Fe atoms at the Fe/Al interface. Alloying promotes the transfer of Fe/Al interfacial electrons between different orbits, enhances the ionic bond properties of Fe-Al, improves the Fe/Al interface binding capacity, improves the brittle fracture of Fe/Al interface, and the alloying effect of Sn most notable. On the basis of this, the laser lap welding test of Sn and Zr powder was carried out on 1.4mm thick DC51D+ZF galvanized steel and 1.2mm thick 6016 aluminum alloy specimen. The results show that the addition of powder can promote the flowability of the molten bath and change the composition and microstructure of the joint interface. The tensile strength of the steel/aluminum joint is 327.41MPa and the elongation is 22.93% with the addition of Sn powder, which is obviously improved compared with the addition of Zr powder and without the addition of powder.

  15. Ultrahigh carbon steels, Damascus steels, and superplasticity

    Energy Technology Data Exchange (ETDEWEB)

    Sherby, O.D. [Stanford Univ., CA (United States). Dept. of Materials Science and Engineering; Wadsworth, J. [Lawrence Livermore National Lab., CA (United States)

    1997-04-01

    The processing properties of ultrahigh carbon steels (UHCSs) have been studied at Stanford University over the past twenty years. These studies have shown that such steels (1 to 2.1% C) can be made superplastic at elevated temperature and can have remarkable mechanical properties at room temperature. It was the investigation of these UHCSs that eventually brought us to study the myths, magic, and metallurgy of ancient Damascus steels, which in fact, were also ultrahigh carbon steels. These steels were made in India as castings, known as wootz, possibly as far back as the time of Alexander the Great. The best swords are believed to have been forged in Persia from Indian wootz. This paper centers on recent work on superplastic UHCSs and on their relation to Damascus steels. 32 refs., 6 figs.

  16. Performance Evaluation of CMUT-Based Ultrasonic Transformers for Galvanic Isolation.

    Science.gov (United States)

    Heller, Jacques; Boulme, Audren; Alquier, Daniel; Ngo, Sophie; Certon, Dominique

    2018-04-01

    This paper presents the development of a novel acoustic transformer with high galvanic isolation dedicated to power switch triggering. The transformer is based on two capacitive micromachined ultrasonic transducers layered on each side of a silicon substrate; one is the primary circuit, and the other is the secondary circuit. The thickness mode resonance of the substrate is leveraged to transmit the triggering signal. The fabrication and characterization of an initial prototype is presented in this paper. All experimental results are discussed, from the electrical impedance measurements to the power efficiency measurements, for different electrical load conditions. A comparison with a specifically developed finite-element method model is done. Simulations are finally used to identify the optimization rules of this initial prototype. It is shown that the power efficiency can be increased from 35% to 60%, and the transmitted power can be increased from 1.6 to 45 mW/Volt.

  17. Galvanic vestibular stimulation: a novel modulatory countermeasure for vestibular-associated movement disorders

    Directory of Open Access Journals (Sweden)

    Carlos V. Rizzo-Sierra

    2014-01-01

    Full Text Available Motion sickness or kinetosis is the result of the abnormal neural output originated by visual, proprioceptive and vestibular mismatch, which reverses once the dysfunctional sensory information becomes coherent. The space adaptation syndrome or space sickness relates to motion sickness; it is considered to be due to yaw, pith, and roll coordinates mismatch. Several behavioural and pharmacological measures have been proposed to control these vestibular-associated movement disorders with no success. Galvanic vestibular stimulation has the potential of up-regulating disturbed sensory-motor mismatch originated by kinetosis and space sickness by modulating the GABA-related ion channels neural transmission in the inner ear. It improves the signal-to-noise ratio of the afferent proprioceptive volleys, which would ultimately modulate the motor output restoring the disordered gait, balance and human locomotion due to kinetosis, as well as the spatial disorientation generated by gravity transition.

  18. Dissolution-Induced Nanowire Synthesis on Hot-Dip Galvanized Surface in Supercritical Carbon Dioxide.

    Science.gov (United States)

    Kaleva, Aaretti; Saarimaa, Ville; Heinonen, Saara; Nikkanen, Juha-Pekka; Markkula, Antti; Väisänen, Pasi; Levänen, Erkki

    2017-07-11

    In this study, we demonstrate a rapid treatment method for producing a needle-like nanowire structure on a hot-dip galvanized sheet at a temperature of 50 °C. The processing method involved only supercritical carbon dioxide and water to induce a reaction on the zinc surface, which resulted in growth of zinc hydroxycarbonate nanowires into flower-like shapes. This artificial patina nanostructure predicts high surface area and offers interesting opportunities for its use in industrial high-end applications. The nanowires can significantly improve paint adhesion and promote electrochemical stability for organic coatings, or be converted to ZnO nanostructures by calcining to be used in various semiconductor applications.

  19. Atom probe tomography characterization of thin copper layers on aluminum deposited by galvanic displacement.

    Science.gov (United States)

    Zhang, Yi; Ai, Jiahe; Hillier, Andrew C; Hebert, Kurt R

    2012-01-24

    ″Ultrathin″ metallization layers on the order of nanometers in thickness are increasingly used in semiconductor interconnects and other nanostructures. Aqueous deposition methods are attractive methods to produce such layers due to their low cost, but formation of ultrathin layers has proven challenging, particularly on oxide-coated substrates. This work focused on the formation of thin copper layers on aluminum, by galvanic displacement from alkaline aqueous solutions. Analysis by atom probe tomography (APT) showed that continuous copper films of approximately 1 nm thickness were formed, apparently the first demonstration of deposition of ultrathin metal layers on oxidized substrates from aqueous solutions. The APT reconstructions indicate that deposited copper replaced a portion of the surface oxide film on aluminum. The results are consistent with mechanisms in which surface hydride species on aluminum mediate deposition, either by directly reducing cupric ions or by inducing electronic conduction in the oxide, thus enabling cupric ion reduction by Al metal.

  20. Flaw detection on galvanized metallic strips in real time by adaptive thresholding

    Science.gov (United States)

    Macaire, Ludovic; Postaire, Jack-Gerard

    1993-12-01

    This paper describes a vision system designed for automatic inspection of galvanized metallic strips in real-time. First, we present the image acquisition system whose two main components are a linear camera and a specific lighting device. In the second part, an original procedure is proposed in order to segment the line images at the line image acquisition rate. It consists in a fast adaptive thresholding scheme which determines global thresholds for each line image. In order to achieve an exhaustive control of the whole production, these tasks are run in real-time on a specific hardware architecture. The prototype described in the last section of this paper has been integrated on a production line to evaluate its efficacy.

  1. Dissolution-Induced Nanowire Synthesis on Hot-Dip Galvanized Surface in Supercritical Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Aaretti Kaleva

    2017-07-01

    Full Text Available In this study, we demonstrate a rapid treatment method for producing a needle-like nanowire structure on a hot-dip galvanized sheet at a temperature of 50 °C. The processing method involved only supercritical carbon dioxide and water to induce a reaction on the zinc surface, which resulted in growth of zinc hydroxycarbonate nanowires into flower-like shapes. This artificial patina nanostructure predicts high surface area and offers interesting opportunities for its use in industrial high-end applications. The nanowires can significantly improve paint adhesion and promote electrochemical stability for organic coatings, or be converted to ZnO nanostructures by calcining to be used in various semiconductor applications.

  2. GALVANIC MAGNETIC PROPERTIES OF BISMUTH THIN FILMS DOPED WITH TELLURIUM MADE BY THERMAL VACUUM EVAPORATION

    Directory of Open Access Journals (Sweden)

    V. A. Komarov

    2013-01-01

    Full Text Available The influence of n-type impurity of tellurium (concentration range from 0.005 atomic % Te to 0.15 atomic % Te on galvanic magnetic properties (resistivity, magnetic resistance and Hall constant of Bi thin films with various thicknesses was studied. The properties were measured in temperature range from 77 to 300 K. It was established that the classical size effect in the films is significant and decreases with higher concentration of Te impurity. The analysis of experimental results was carried out in approximation of the law of Jones-Schoenberg dispersion for Bi films doped with tellurium. Calculation of concentration and mobility of charge carriers in the studied films was made.

  3. Controllable galvanic synthesis of triangular Ag-Pd alloy nanoframes for efficient electrocatalytic methanol oxidation.

    Science.gov (United States)

    Xu, Lin; Luo, Zhimin; Fan, Zhanxi; Yu, Sijia; Chen, Junze; Liao, Yusen; Xue, Can

    2015-06-08

    Triangular Ag-Pd alloy nanoframes were successfully synthesized through galvanic replacement by using Ag nanoprisms as sacrificial templates. The ridge thickness of the Ag-Pd alloy nanoframes could be readily tuned by adjusting the amount of the Pd source during the reaction. These obtained triangular Ag-Pd alloy nanoframes exhibit superior electrocatalytic activity for the methanol oxidation reaction as compared with the commercial Pd/C catalyst due to the alloyed Ag-Pd composition as well as the hollow-framed structures. This work would be highly impactful in the rational design of future bimetallic alloy nanostructures with high catalytic activity for fuel cell systems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Fabrication of biomimetic superhydrophobic surface on engineering materials by a simple electroless galvanic deposition method.

    Science.gov (United States)

    Xu, Xianghui; Zhang, Zhaozhu; Yang, Jin

    2010-03-02

    We have reported an easy means in this paper to imitate the "lotus leaf" by constructing a superhydrophobic surface through a process combining both electroless galvanic deposition and self-assembly of n-octadecanethiol. Superhydrophobicity with a static water contact angle of about 169 +/- 2 degrees and a sliding angle of 0 +/- 2 degrees was achieved. Both the surface chemical compositions and morphological structures were analyzed. We have obtained a feather-like surface structure, and the thickness of the Ag film is about 10-30 microm. The stability of the superhydrophobic surface was tested under the following three conditions: (1) pH value from 1 to 13; (2) after freezing treatment at -20 degrees C; (3) at ambient temperature. It shows a notable stability in that the contact angle of the sample still remained higher than 150 degrees in different conditions. It can be concluded that our approach can provide an alternative way to fabricate stable superhydrophobic materials.

  5. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    Energy Technology Data Exchange (ETDEWEB)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-03-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed.

  6. Effects of deuterium oxide and galvanic vestibular stimulation on visual cortical cell function

    International Nuclear Information System (INIS)

    Reinis, S.; Landolt, J.P.; Weiss, D.S.; Money, K.E.

    1984-01-01

    The spontaneous and evoked unit activities of complex visual cortical cells were recorded from Brodmann's area 18 in immobilized, unanesthetized cats before, during, and after stimulation of the vestibular system. The vestibular system was stimulated by intravenous injection of deuterium oxide (D2O)--a noted nystagmogenic agent--or by direct galvanic stimulation of the labyrinth. Measures of the receptive-field areas, poststimulus time histograms, directional preferences, and the optimal speed of the light bar stimulating the cell were obtained before and after the application of D2O. Directional preferences were determined in a novel manner, using a method derived from a hierarchical clustering technique. Data were collected and analyzed from a) visual cortical cells in cats with intact labyrinths, b) visual cortical cells in cats following bilateral labrinthectomies, and c) nonvisual cortical cells in cats with intact labyrinths. The other cellular characteristics were also altered by the D2O. Galvanic stimulation of the labyrinth resembles, in its effects, the injection of D2O. In labyrinth-intact cats, the time course of area 18 spontaneous activity dramatically increased 30 min or more after D2O was administered. It peaked 2-3 h later and still had not returned to preinjection levels even 7 h after the D2O administration. In bilaterally labyrinthectomized cats, the spontaneous activity of the visual cells did not change following D2O administration. In nonvisual cells from labyrinth-intact cats, the spontaneous activity demonstrated a slight but significant decrease over time after D2O injection. In pilot studies, the cats were injected with D2O. Within 8-10 min afterward, signs of positional nystagmus commenced; and within 30 min, problems in maintaining balance were noted. This continued for 7-8 h before disappearing. In the labyrinthectomized animals, such effects were not observed

  7. Treatment and recovery of liquid wastes from galvanic process; Tratamiento y reutilizacion de efluentes liquidos generados en el proceso de galvanizado

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Dominguez, F.J.; Alonso Suarez, F.J.; Maranon Maison, E. [Dpto. de Congruccion e Ingenieria de la Fabricacion, E.T.S.I.I., Univ. de Oviedo, Oviedo (Spain)

    1997-04-01

    Within the metal finishing industry, and in particular the galvanizing industry, one of the main problems to be confronted is that of the generation and subsequent handling of liquid residues. In the specific case of galvanization, these residues are generated basically in the exhausted pickling baths employed in treating surfaces before galvanization, as well as in the rinse water used in the distinct stages of the process. The purpose of the article is to provide an overview of the large number of possibilities for reducing and recovering these effluents. (Author) 29 refs.

  8. Order to the Petition to Object to United States Steel Corporation, Granite City Works, St. Louis, Illinois, Title V Operating Permit

    Science.gov (United States)

    This document may be of assistance in applying the Title V air operating permit regulations. This document is part of the Title V Petition Database available at www2.epa.gov/title-v-operating-permits/title-v-petition-database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  9. Tunneling corrosion mechanism of the hot forged austenitic stainless steel in highly oxidizing nitric acid

    International Nuclear Information System (INIS)

    Nagano, Hiroo; Kajimura, Haruhiko

    1993-01-01

    Austenitic Stainless Steels have been used for reprocessing plants where spent nuclear fuels are dealt with in hot nitric acid. Conventional stainless steels are resistant enough to nitric acid. However, they are prone to localized corrosion when nitric acid becomes highly oxidizing with birth of oxidants such as Ce 4+ or Cr 6+ ion during the reprocessing. Pitting type corrosion, so-called tunneling or end-grain corrosion occurred on the forgings of 25%-20%-Nb stainless steel (310Nb stainless steel) in such nitric acid solutions because of transpassive corrosion. It has been well known that metal surfaces of steel products casted, forged or rolled are susceptible to the tunneling corrosion in aggressive corrosion media. Nevertheless, neither clear explanations of the mechanism nor definite countermeasures have been proposed yet. This paper describes the mechanism and countermeasures on the tunneling corrosion of stainless steels in nitric acid relevant to spent nuclear fuel reprocessing. The results obtained are as follows: both general and intergranular corrosion occur on austenitic stainless steels in boiling 8N HNO 3 with Cr 6+ ions. Tunneling corrosion is initiated and propagates at the metal surfaces of 310Nb stainless steel forgings along chromium depleted areas vertical to metal flows. The grooves due to the tunneling corrosion are of diameters of 0.5 to 2 mm with a maximum depth of 6mm depending on exposure time and Cr 6+ concentration in nitric acid. Tunneling corrosion proceeds by build up of galvanic corrosion cells with Cr depleted parts as anodes and their neighborhoods as cathodes. The Cr depleted parts are formed during solidification of ingots and still retained parallel to the metal flow even after forging. The ESR (Electro Slag Remelting) is one of the useful preventive methods to tunneling corrosion from the view point of steel homogenization

  10. Special stainless steels for sea water service

    International Nuclear Information System (INIS)

    Tomaselli, A.C.

    1983-01-01

    Very exacting demands are made on the corrosion resistance and mechanical properties of materials which in their service come into contact with seawater, and in many cases simultaneously with corrosive process solutions. The demand for higher alloy stainless steels for seawater application is rising in pace with the increasing requirements for safety and operation economy. The corrosion conditions in seawater and the resistance of stainless steels in this medium will be dealt with in the following. Sanicro 28 will then be compared with stainless steels, types AISI 304, 316 and 317, as well as with Alloy 20, Alloy 825 and SANDVIK 2RK65. (Author) [pt

  11. Corrosion of welded steel piping in domestic hot water: A case history. Corrosion de una instalacion de tubos soldados de acero galvanizado para agua caliente

    Energy Technology Data Exchange (ETDEWEB)

    Herrera, E.J.; Soria, L.; Gallardo, J.M.

    1993-01-01

    Many leaks had occurred after seven years of service in the hot sanitary water system of building. The results of the failure analysis have led to the conclusion that the reduced life of the piping system was primarily promoted by the use of a dissimilar metal (galvanized steel-copper) installation and by an excessive service temperature. Through precuations were taking to electrically insulate both types of tubing by employing dielectric fittings and water flow followed the ''rule of flow'' (zinc[yields] copper), an indirect galvanic attach on galvanized steel took place. Localized corrosion was originated by microcells formed by plating out of soluble copper. Corrosive attack was most severe at weld seams. The microstructure of the weld zone was very different from that of the surrounding pipe. In addition, some pipes presented signs of incomplete fusion (welding without filling metal) and others had protruding weld seams which produced crevice attack and erosion-corrosion, respectively. Author (10 refs.)

  12. New types of coating systems for steel sheets by high-rate evaporation in combination with plasma processes

    Energy Technology Data Exchange (ETDEWEB)

    Scheffel, B.; Metzner, C. [Fraunhofer-Institut fuer Elektronenstrahl und Plasmatechnik (FEP), Dresden (Germany); Ehlers, K.D. [Salzgitter AG Stahl und Technologie (Germany); Schuhmacher, B. [Dortmunder Oberflaechencentrum GmbH, Dortmund (Germany); Flossdorf, F.J.; Steinbeck, G. [Verein Deutscher Eisenhuettenleute (VDEh), Duesseldorf (Germany); Steffen, R. [Stahlwerke Bremen GmbH (Germany); Hagler, J. [voestalpine Stahl GmbH, Linz (Austria)

    2002-03-01

    High-rate evaporation in combination with plasma processes is a promising approach to obtain new types of steel sheet coating with improved corrosion resistance and application properties. To estimate the potential for the application of PVD-coatings (physical vapour deposition) different coating systems for steel sheet as well as for hot-dip or electro-galvanized steel sheet were designed. The samples were produced on a laboratory scale using PVD processes with very high deposition rates (in the order of 1 {mu}m s{sup -1}) as well as high-power plasma processes for the pre-treatment. The relationship between the composition, microstructure and properties of the coating systems, in particular concerning corrosion protection, abrasion during forming, phosphating and paint adhesion, were studied. It was found that the corrosion resistance of galvanized steel sheets can be considerably improved by vapour deposition of metal or inorganic films with a thickness of several hundred nanometers. Investigations on vapour deposition of titanium and stainless steel coatings on steel sheets, for applications in a severely corrosive environment, showed that the corrosion resistance in relation to the coating thickness can be significantly enhanced by means of plasma activation during the vapour deposition process. Finally, an outlook on possible industrial applications including an estimation of the process costs will be presented. For certain coating systems the results look promising. Consequently, these particular coating systems will be investigated in more detail by means of using a large-scale in-line deposition plant for metallic strips and sheets. (orig.)

  13. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    Science.gov (United States)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H.

    2015-12-01

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO2 implanted AISI 304 - examined for different implantation and annealing parameters - is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 1016 cm-2 (Ti+) and 1 × 1017 cm-2 (O+) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 1015 cm-2 (Ti+) and 1 × 1016 cm-2 (O+). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO2 inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  14. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    International Nuclear Information System (INIS)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H.

    2015-01-01

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO 2 implanted AISI 304 – examined for different implantation and annealing parameters – is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 10 16 cm −2 (Ti + ) and 1 × 10 17 cm −2 (O + ) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 10 15 cm −2 (Ti + ) and 1 × 10 16 cm −2 (O + ). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO 2 inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  15. Stoichiometric titanium dioxide ion implantation in AISI 304 stainless steel for corrosion protection

    Energy Technology Data Exchange (ETDEWEB)

    Hartwig, A.; Decker, M.; Klein, O.; Karl, H., E-mail: helmut.karl@physik.uni-augsburg.de

    2015-12-15

    The aim of this study is to evaluate the applicability of highly chemically inert titanium dioxide synthesized by ion beam implantation for corrosion protection of AISI 304 stainless steel in sodium chloride solution. More specifically, the prevention of galvanic corrosion between carbon-fiber reinforced plastic (CFRP) and AISI 304 was investigated. Corrosion performance of TiO{sub 2} implanted AISI 304 – examined for different implantation and annealing parameters – is strongly influenced by implantation fluence. Experimental results show that a fluence of 5 × 10{sup 16} cm{sup −2} (Ti{sup +}) and 1 × 10{sup 17} cm{sup −2} (O{sup +}) is sufficient to prevent pitting corrosion significantly, while galvanic corrosion with CFRP can already be noticeably reduced by an implantation fluence of 5 × 10{sup 15} cm{sup −2} (Ti{sup +}) and 1 × 10{sup 16} cm{sup −2} (O{sup +}). Surface roughness, implantation energy and annealing at 200 °C and 400 °C show only little influence on the corrosion behavior. TEM analysis indicates the existence of stoichiometric TiO{sub 2} inside the steel matrix for medium fluences and the formation of a separated metal oxide layer for high fluences.

  16. Trends in steel technology

    International Nuclear Information System (INIS)

    Anon.

    1980-01-01

    Dual phase steels, composite products, and microalloyed steels are making inroads in the automotive industry applications for bumpers, automotive parts, bodies, mechanical parts, suspension and steering equipment and truck bumpers. New steels are also used to support solar mirrors and cells, in corrosive environments in the oil and gas industry, fusion reactors, and pressure vessels in nuclear power plants

  17. Development and optimization of operational parameters of a gas-fired baking oven

    Directory of Open Access Journals (Sweden)

    Afolabi Tunde MORAKINYO

    2017-12-01

    Full Text Available This study presented the development and optimization of operational parameters of an indigenous gas-fired bread-baking oven for small-scale entrepreneur. It is an insulated rectangular box-like chamber, made of galvanized-steel sheets and having a total dimension of 920mm×650mm×600mm. This oven consists of two baking compartments and three combustion chambers. The oven characteristics were evaluated in terms of the baking capacity, baking efficiency and weight loss of the baked bread. The physical properties of the baked breads were measured and analyzed using Duncan multiple range test of one way ANOVA at significant level of p<0.05. These properties were optimized to determine the optimum baking temperature using 3D surface response plot of Statistical Release 7. The baking capacity, baking efficiency, weight loss and optimum baking temperature were: 12.5 kg/hr, 87.8%, 12.5 g, 200-220oC, respectively. The physical properties of baked bread dough were found to correspond with the imported product (control sample. These results showed that, the developed gas-fired baking oven can be adopted for baking of bread at domestic and commercial levels.

  18. Comparative Analysis of Semiconductor Power Losses of Galvanically Isolated Quasi-Z-Source and Full-Bridge Boost DC-DC Converters

    Directory of Open Access Journals (Sweden)

    Kosenko Roman

    2015-07-01

    Full Text Available This paper compares semiconductor losses of the galvanically isolated quasi-Z-source converter and full-bridge boost DC-DC converter with active clamping circuit. Operation principle of both converters is described. Short design guidelines are provided as well. Results of steady state analysis are used to calculate semiconductor power losses for both converters. Analytical expressions are derived for all types of semiconductor power losses present in these converters. The theoretical results were verified by means of numerical simulation performed in the PSIM simulation software. Its add-on module “Thermal module” was used to estimate semiconductor power losses using the datasheet parameters of the selected semiconductor devices. Results of calculations and simulation study were obtained for four operating points with different input voltage and constant input current to compare performance of the converters in renewable applications, like photovoltaic, where input voltage and power can vary significantly. Power loss breakdown is detailed and its dependence on the converter output power is analyzed. Recommendations are given for the use of the converter topologies in applications with low input voltage and relatively high input current.

  19. Prediction of Continuous Cooling Transformation Diagrams for Dual-Phase Steels from the Intercritical Region

    Science.gov (United States)

    Colla, V.; Desanctis, M.; Dimatteo, A.; Lovicu, G.; Valentini, R.

    2011-09-01

    The purpose of the present work is the implementation and validation of a model able to predict the microstructure changes and the mechanical properties in the modern high-strength dual-phase steels after the continuous annealing process line (CAPL) and galvanizing (Galv) process. Experimental continuous cooling transformation (CCT) diagrams for 13 differently alloying dual-phase steels were measured by dilatometry from the intercritical range and were used to tune the parameters of the microstructural prediction module of the model. Mechanical properties and microstructural features were measured for more than 400 dual-phase steels simulating the CAPL and Galv industrial process, and the results were used to construct the mechanical model that predicts mechanical properties from microstructural features, chemistry, and process parameters. The model was validated and proved its efficiency in reproducing the transformation kinetic and mechanical properties of dual-phase steels produced by typical industrial process. Although it is limited to the dual-phase grades and chemical compositions explored, this model will constitute a useful tool for the steel industry.

  20. Galvanic replacement mediated synthesis of hollow Pt nanocatalysts: Significance of residual Ag for the H{sub 2} evolution reaction

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, Vipul; O' Mullane, Anthony P.; Bhargava, Suresh K. [School of Applied Sciences, RMIT University, GPO Box 2476V, Melbourne VIC 3001 (Australia)

    2009-08-15

    With the increasing popularity of the galvanic replacement approach towards the development of bimetallic nanocatalysts, special emphasis has been focused on minimizing the use of expensive metal (e.g. Pt), in the finally formed nanomaterials (e.g. Ag/Pt system as a possible catalyst for fuel cells). However, the complete removal of the less active sacrificial template is generally not achieved during galvanic replacement, and its residual presence may significantly impact on the electrocatalytic properties of the final material. Here, we investigate the hydrogen evolution reaction (HER) activity of Ag nanocubes replaced with different amounts of Pt, and demonstrate how the bimetallic composition significantly affects the activity of the alloyed nanomaterial. (author)

  1. The effect of zinc bath temperature on the morphology, texture and corrosion behaviour of industrially produced hot-dip galvanized coatings

    Directory of Open Access Journals (Sweden)

    A. Bakhtiari

    2014-03-01

    Full Text Available The purpose of this work is to identify the influence of zinc bath temperature on the morphology, texture and corrosion behavior of hot-dip galvanized coatings. Hot-dip galvanized samples were prepared at temperature in the range of 450-480 °C in steps of 10 °C, which is the conventional galvanizing temperature range in the galvanizing industries. The morphology of coatings was examined with optical microscopy and scanning electron microscopy (SEM. The composition of the coating layers was determined using energy dispersive spectroscopy (EDS analysis. The texture of the coatings was evaluated using X-ray diffraction. Corrosion behavior was performed using salt spray cabinet test and Tafel extrapolation test. From the experimental results, it was found that increasing the zinc bath temperature affects the morphology of the galvanized coatings provoking the appearance of cracks in the coating structure. These cracks prevent formation of a compact structure. In addition, it was concluded that (00.2 basal plane texture component was weakened by increasing the zinc bath temperature and, conversely, appearance of (10.1 prism component, (20.1 high angle pyramidal component and low angle component prevailed. Besides, coatings with strong (00.2 texture component and weaker (20.1 components have better corrosion resistance than the coatings with weak (00.2 and strong (20.1 texture components. Furthermore, corrosion resistance of the galvanized coatings was decreased by increasing the zinc bath temperature.

  2. Weldability of Stainless Steels

    International Nuclear Information System (INIS)

    Saida, Kazuyoshi

    2010-01-01

    It gives an outline of metallographic properties of welding zone of stainless steels, generation and mechanisms of welding crack and decreasing of corrosion resistance of welding zone. It consists of seven chapters such as introduction, some kinds of stainless steels and properties, metallographic properties of welding zone, weld crack, toughness of welding zone, corrosion resistance and summary. The solidification modes of stainless steels, each solidification mode on the cross section of Fe-Cr-Ni alloy phase diagram, each solidification mode of weld stainless steels metal by electron beam welding, segregation state of alloy elements at each solidification mode, Schaeffler diagram, Delong diagram, effects of (P + S) mass content in % and Cr/Ni equivalent on solidification cracking of weld stainless steels metal, solidification crack susceptibility of weld high purity stainless steels metal, effects of trace impurity elements on solidification crack susceptibility of weld high purity stainless steels metal, ductile fracture susceptibility of weld austenitic stainless steels metal, effects of H2 and ferrite content on generation of crack of weld 25Cr-5N duplex stainless steels, effects of O and N content on toughness of weld SUS 447J1 metals, effect of ferrite content on aging toughness of weld austenitic stainless steel metal, corrosion morphology of welding zone of stainless steels, generation mechanism of knife line attack phenomenon, and corrosion potential of some kinds of metals in seawater at room temperature are illustrated. (S.Y.)

  3. The steel scrap age.

    Science.gov (United States)

    Pauliuk, Stefan; Milford, Rachel L; Müller, Daniel B; Allwood, Julian M

    2013-04-02

    Steel production accounts for 25% of industrial carbon emissions. Long-term forecasts of steel demand and scrap supply are needed to develop strategies for how the steel industry could respond to industrialization and urbanization in the developing world while simultaneously reducing its environmental impact, and in particular, its carbon footprint. We developed a dynamic stock model to estimate future final demand for steel and the available scrap for 10 world regions. Based on evidence from developed countries, we assumed that per capita in-use stocks will saturate eventually. We determined the response of the entire steel cycle to stock saturation, in particular the future split between primary and secondary steel production. During the 21st century, steel demand may peak in the developed world, China, the Middle East, Latin America, and India. As China completes its industrialization, global primary steel production may peak between 2020 and 2030 and decline thereafter. We developed a capacity model to show how extensive trade of finished steel could prolong the lifetime of the Chinese steelmaking assets. Secondary steel production will more than double by 2050, and it may surpass primary production between 2050 and 2060: the late 21st century can become the steel scrap age.

  4. Alexander von Humboldt: galvanism, animal electricity, and self-experimentation part 2: the electric eel, animal electricity, and later years.

    Science.gov (United States)

    Finger, Stanley; Piccolino, Marco; Stahnisch, Frank W

    2013-01-01

    After extensive experimentation during the 1790s, Alexander von Humboldt remained skeptical about "animal electricity" (and metallic electricity), writing instead about an ill-defined galvanic force. With his worldview and wishing to learn more, he studied electric eels in South America just as the new century began, again using his body as a scientific instrument in many of his experiments. As had been the case in the past and for many of the same reasons, some of his findings with the electric eel (and soon after, Italian torpedoes) seemed to argue against biological electricity. But he no longer used galvanic terminology when describing his electric fish experiments. The fact that he now wrote about animal electricity rather than a different "galvanic" force owed much to Alessandro Volta, who had come forth with his "pile" (battery) for multipling the physical and perceptable effects of otherwise weak electricity in 1800, while Humboldt was deep in South America. Humboldt probably read about and saw voltaic batteries in the United States in 1804, but the time he spent with Volta in 1805 was probably more significant in his conversion from a galvanic to an electrical framework for understanding nerve and muscle physiology. Although he did not continue his animal electricity research program after this time, Humboldt retained his worldview of a unified nature and continued to believe in intrinsic animal electricity. He also served as a patron to some of the most important figures in the new field of electrophysiology (e.g., Hermann Helmholtz and Emil du Bois-Reymond), helping to take the research that he had participated in to the next level.

  5. Can galvanic skin conductance be used as an objective indicator of children?s anxiety in the dental setting?

    OpenAIRE

    Najafpour, Ebrahim; Asl-Aminabadi, Naser; Nuroloyuni, Sara; Jamali, Zahra; Shirazi, Sajjad

    2017-01-01

    Background Assessment of procedural distress is essential at assisting children during invasive dental treatments. This study aimed to determine the validity and reliability of galvanic skin response as a measure for assessment of dental anxiety in children. Material and Methods 151 children, aged 5-7 years, participated in this study. Similar dental treatments were rendered to all subjects. At the beginning and end of the session, modified child dental anxiety scale (MCDAS), clinical anxiety...

  6. Study of the Reaction Rate of Gold Nanotube Synthesis from Sacrificial Silver Nanorods through the Galvanic Replacement Method

    OpenAIRE

    Sunil Kwon; Hyunbae Dong; Sang-Yup Lee

    2010-01-01

    An investigation was carried out about the gold nanotube synthesis via a galvanic replacement reaction. The progress of the gold nanotube synthesis was investigated using electron microscopy and UV-Vis spectroscopy. In addition, the reaction rates of gold nanotube formation in the early stage of the reaction were studied. The chlorine ion concentration linearly increased with the gold precursor concentration but deviated from the stoichiometric amounts. This deviation was probably due to AgCl...

  7. Changeability of tissue's magnetic remanence after galvanic-magnetostimulation in upper-back pain treatment.

    Science.gov (United States)

    Dyszkiewicz, Andrzej Jan; Kępiński, Paweł; Połeć, Paweł; Chachulski, Damian; Nowak-Kostrzewska, Ewa

    2015-11-01

    Research was conducted on parametric profiles of healthy subjects and patients with cervico-brachial pain syndrome resulting from C4/5 and/or C5/6 discopathy, including magnetic remanence of tissues in marker points 1-12 (L+R) and functional parameters, and their subsequent change after treatment in group A, using method of push-pull galvanic magnetostimulation (GMT 2.0). GMT 2.0 device, comprised of one air solenoid and three galvanic solenoids in electrolytic tubs, was designed for push-pull magnetostimulation of the head, coupled with simultaneous stimulation of the limbs. Clinical trial was conducted in Outpatient Private Clinic "VIS" under the auspices of Silesian Higher Medical School in Katowice, Poland. 55 subjects participated in the study: control group K consisted of 23 healthy individuals, whereas 33 patients in group A were treated using GMT 2.0. Only patients in group A were treated with GMT 2.0 during 40-min sessions over a period of 10 days. Parametric profile of the patients was defined using various measurements: electronic SFTR test (C-Th-shoulders), HR, RR, BDI and VAS tests, magnetic remanence in marker points 1-12 (L+R) and blood parameters: HB, ER, CREA, BIL, K(+), Na(+), Cl(-) Fe(2+), Ca(2+) and Mg(2+). There was a significant reduction in pain (VAS), increase in the range of motion (SFTR), lower depression symptoms (BDI), slower heart rate (HR), lower blood pressure (RR), greater concentration of Mg(2+), K(+), Ca(2+)ions and reduction in the concentration of BIL, CREA Fe(2+) after GMT 2.0 treatment in group A. Evaluation of magnetic remanence in marker points M1-12 (L+R) initially showed higher values in group K, which after treatment were normalized to values similar to those in group K. GMT 2.0 treatment in group A resulted in normalization of magnetic remanence, synergically with increased range of motion (SFTR test), decreased HR and RR parameters, smaller depressive trends (BDI test), as well as increased ion levels (K(+), Mg(2+), Ca(2

  8. Galvanic Replacement Coupled to Seeded Growth as a Route for Shape-Controlled Synthesis of Plasmonic Nanorattles.

    Science.gov (United States)

    Polavarapu, Lakshminarayana; Zanaga, Daniele; Altantzis, Thomas; Rodal-Cedeira, Sergio; Pastoriza-Santos, Isabel; Pérez-Juste, Jorge; Bals, Sara; Liz-Marzán, Luis M

    2016-09-14

    Shape-controlled synthesis of metal nanoparticles (NPs) requires mechanistic understanding toward the development of modern nanoscience and nanotechnology. We demonstrate here an unconventional shape transformation of Au@Ag core-shell NPs (nanorods and nanocubes) into octahedral nanorattles via room-temperature galvanic replacement coupled with seeded growth. The corresponding morphological and chemical transformations were investigated in three dimensions, using state-of-the-art X-ray energy-dispersive spectroscopy (XEDS) tomography. The addition of a reducing agent (ascorbic acid) plays a key role in this unconventional mechanistic path, in which galvanic replacement is found to dominate initially when the shell is made of Ag, while seeded growth suppresses transmetalation when a composition of Au:Ag (∼60:40) is reached in the shell, as revealed by quantitative XEDS tomography. This work not only opens new avenues toward the shape control of hollow NPs beyond the morphology of sacrificial templates, but also expands our understanding of chemical transformations in nanoscale galvanic replacement reactions. The XEDS electron tomography study presented here can be generally applied to investigate a wide range of nanoscale morphological and chemical transformations.

  9. Saccule contribution to immediate early gene induction in the gerbil brainstem with posterior canal galvanic or hypergravity stimulation

    Science.gov (United States)

    Marshburn, T. H.; Kaufman, G. D.; Purcell, I. M.; Perachio, A. A.

    1997-01-01

    Immunolabeling patterns of the immediate early gene-related protein Fos in the gerbil brainstem were studied following stimulation of the sacculus by both hypergravity and galvanic stimulation. Head-restrained, alert animals were exposed to a prolonged (1 h) inertial vector of 2 G (19.6 m/s2) head acceleration directed in a dorso-ventral head axis to maximally stimulate the sacculus. Fos-defined immunoreactivity was quantified, and the results compared to a control group. The hypergravity stimulus produced Fos immunolabeling in the dorsomedial cell column (dmcc) of the inferior olive independently of other subnuclei. Similar dmcc labeling was induced by a 30 min galvanic stimulus of up to -100 microA applied through a stimulating electrode placed unilaterally on the bony labyrinth overlying the posterior canal (PC). The pattern of vestibular afferent firing activity induced by this galvanic stimulus was quantified in anesthetized gerbils by simultaneously recording from Scarpa's ganglion. Only saccular and PC afferent neurons exhibited increases in average firing rates of 200-300%, suggesting a pattern of current spread involving only PC and saccular afferent neurons at this level of stimulation. These results suggest that alteration in saccular afferent firing rates are sufficient to induce Fos-defined genomic activation of the dmcc, and lend further evidence to the existence of a functional vestibulo-olivary-cerebellar pathway of adaptation to novel gravito-inertial environments.

  10. A study of phase and morphology changes occurring as a result of galvanic reactions with FeO nanocrystals

    Science.gov (United States)

    Onserio, Benard Obae

    Recently, iron oxide nanoparticles have attracted great attention from various research groups. This is due to their potential applications in various fields such as biomedicine, environmental remediation, storage media, catalysis, and as anode materials for lithium-ion batteries. The objective of this study is to develop a synthesis of hollow Fe3O4 nanoparticles via galvanic reaction between FeO nanocrystals and oxidizing agents in which a nanoscale Kirkendall effect occurs. The objective is based on prior results in which it was demonstrated that Cu2+ oxidized MnO nanocrystals to yield hollow Mn3O4 nanoparticles. The analogous process starting from FeO is expected to be even more thermodynamically favorable. Despite efforts to obtain FeO nanocrystals, the magnetite Fe3O 4 phase was obtained. With this sample, attempts were made towards galvanic reactions in the presence of Cu2+. The initial result of the reaction of Fe3O4 nanocrystals with Cu2+ was unexpected, and FeO was obtained; however, the result could not be reproduced. Later efforts focused on attempting to understand the galvanic reaction that took place leading to the formation of FeO. Thus reaction of Fe3O 4 with oleylamine, silver (I), and ascorbic acid were studied. Data for the phase and morphological changes of the iron oxides will be presented.

  11. Effect of dissolved oxygen, hydrazine and pH outside the crevice on the galvanic corrosion of support plate alloys

    International Nuclear Information System (INIS)

    McKubre, M.C.H.

    1985-01-01

    A study has been performed of the initial corrosion of support structure alloys in crevices of various geometries, when galvanically coupled to alloy 600. Corrosion rates were monitored continuously by measuring the galvanic current flowing in each couple, transduced by a zero impedance ammeter. Experiments were performed in a single-pass flowing electrolyte system, with AVT water pumped through alloy 600 tubing past the orifice of each crevice. Fourteen crevices were studied simultaneously in two parallel flow arms containing seven specimens each. The steady state AVT water pH/hydrazine/oxygen concentrations were controlled by microcomputer, allowing the effect of secondary water chemistry on the corrosion rate to be studied easily. Control of the crevice electrolyte composition was achieved by separately pumping electrolyte, at a low rate, directly into the crevices of the seven specimens in the lower flow arm. In addition, a high pressure syringe was used to introduce chemicals directly into the secondary or crevice electrolyte flow streams, in order to rapidly evaluate the influence of potential corrodent or corrosion control agents on the galvanic corrosion rates. Specimens were studied in the five basic geometries

  12. Galvanic skin response test: a new quantitative diagnostic method for Frey syndrome.

    Science.gov (United States)

    Tuzemen, Gokhan; Basut, Oguz; Ozmen, Omer Afsin; Coskun, Hamdi Hakan

    2013-07-01

    Frey syndrome is one of the most common complications following parotid surgery. The current most common test for objectively diagnosing Frey syndrome is Minor starch-iodine test. This test might be insufficient because its results are not quantitative and therefore tests with quantitative results are investigated. The objective of this study was to investigate the efficiency of galvanic skin response (GSR) test, which measures changes in skin resistance, as a method with quantitative results for diagnosis of Frey syndrome. Thirty patients who underwent superficial parotidectomy were assessed postoperatively (mean, 24.7 ± 25.7 months; range, 6-109 months). Patients completed a symptomatic evaluation questionnaire and underwent Minor starch-iodine test and GSR. Diagnostic validity of GSR test was found to be >2.91 following analysis. Sensitivity and specificity of this value were 100% and 55%, respectively, based on symptomatic assessment. Sensitivity and specificity were 87.5% and 57.1%, respectively, based on Minor starch-iodine test. When compared to symptomatic evaluation of patients who underwent superficial parotidectomy, GSR test was shown to be 100% sensitive in diagnosing Frey syndrome and quantitative results of GSR test could determine severity of Frey syndrome.

  13. Vitrification of galvanic solid wastes: solutions for the east area of Sao Paulo, Brazil

    International Nuclear Information System (INIS)

    Mattos, Cleiton dos Santos; Castanho, Sonia Regina Homem de Mello

    2011-01-01

    Galvanic solid waste have elevated levels of heavy metals and usually are stocked in the industry, creating a worrisome environmental liabilities. This disturbing fact is aggravated in areas densely populated as the area east of Sao Paulo, which has a pole of industrial electroplating of chrome. The present paper, we describe and provide a technological option for the disposal of waste generated by this activity using techniques that allow the incorporation of these in a glass matrix. The wastes were characterized by XRF, EDS, ICP-AES, AAS, DTA/TGA, XRD and SEM-FEG and embedded in glass and frits made from the system SiO - CaO-Na O , with additions of up to 30% by weight. The results of the analysis of residues showed the majority presence of Ni, Cr, B, Cu, Ca and S. The resulting glasses showed that heavy metals were incorporated into its structure and probably replacing the Ca and Na. In addition, the products showed specific colors indicating the possibility of use in some segments of manufacturing in ceramics with glazes, loading and pigments. (author)

  14. Galvanic vestibular stimulation may improve anterior bending posture in Parkinson's disease.

    Science.gov (United States)

    Okada, Yohei; Kita, Yorihiro; Nakamura, Junji; Kataoka, Hiroshi; Kiriyama, Takao; Ueno, Satoshi; Hiyamizu, Makoto; Morioka, Shu; Shomoto, Koji

    2015-05-06

    This study investigated the effects of binaural monopolar galvanic vestibular stimulation (GVS), which likely stimulates the bilateral vestibular system, on the anterior bending angle in patients with Parkinson's disease (PD) with anterior bending posture in a single-blind, randomized sham-controlled crossover trial. The seven PD patients completed two types of stimulation (binaural monopolar GVS and sham stimulation) applied in a random order 1 week apart. We measured each patient's anterior bending angles while he or she stood with eyes open and eyes closed before/after the stimulations. The anterior bending angles in both the eyes-open and the eyes-closed conditions were significantly reduced after the GVS. The amount of change in the eyes-closed condition post-GVS was significantly larger than that by sham stimulation. The amount of change in anterior bending angles in the GVS condition was not significantly correlated with Unified Parkinson's Disease Rating Scale motor score, disease duration, the duration of the postural deformities, and the anterior bending angles before the GVS. Binaural monopolar GVS might improve anterior bending posture in PD patients, irrespective of the duration and the severity of disease and postural deformities. Binaural monopolar GVS might be a novel treatment strategy to improve anterior bending posture in PD.

  15. In vivo non-thermal irreversible electroporation impact on rat liver galvanic apparent internal resistance

    International Nuclear Information System (INIS)

    Golberg, A; Laufer, S; Rabinowitch, H D; Rubinsky, B

    2011-01-01

    Non-thermal irreversible electroporation (NTIRE) is a biophysical phenomenon which involves application of electric field pulses to cells or tissues, causing certain rearrangements in the membrane structure leading to cell death. The treated tissue ac impedance changes induced by electroporation were shown to be the indicators for NTIRE efficiency. In a previous study we characterized in vitro tissue galvanic apparent internal resistance (GAIR) changes due to NTIRE. Here we describe an in vivo study in which we monitored the GAIR changes of a rat liver treated by NTIRE. Electrical pulses were delivered through the same Zn/Cu electrodes by which GAIR was measured. GAIR was measured before and for 3 h after the treatment at 15 min intervals. The results were compared to the established ac bioimpedance measurement method. A decrease of 33% was measured immediately after the NTIRE treatment and a 40% decrease was measured after 3 h in GAIR values; in the same time 40% and 47% decrease respectively were measured by ac bioimpedance analyses. The temperature increase due to the NTIRE was only 0.5 deg. C. The results open the way for an inexpensive, self-powered in vivo real-time NTIRE effectiveness measurement.

  16. Standard practice for conducting wire-on-bolt test for atmospheric galvanic corrosion

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers the evaluation of atmospheric galvanic corrosion of any anodic material that can be made into a wire when in contact with a cathodic material that can be made into a threaded rod. 1.2 When certain materials are used for the anode and cathode, this practice has been used to rate the corrosivity of atmospheres. 1.3 The wire-on-bolt test was first described in 1955 (1), and has since been used extensively with standard materials to determine corrosivity of atmospheres under the names CLIMAT Test (CLassify Industrial and Marine ATmospheres) (2-5) and ATCORR (ATmospheric CORRosivity) (6-9). 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations p...

  17. Synthesis of Indium Nanowires by Galvanic Displacement and Their Optical Properties

    Directory of Open Access Journals (Sweden)

    Hope Greg

    2008-01-01

    Full Text Available Abstract Single crystalline indium nanowires were prepared on Zn substrate which had been treated in concentrated sulphuric acid by galvanic displacement in the 0.002 mol L−1In2(SO43-0.002 mol L−1SeO2-0.02 mol L−1SDS-0.01 mol L−1citric acid aqueous solution. The typical diameter of indium nanowires is 30 nm and most of the nanowires are over 30 μm in length. XRD, HRTEM, SAED and structural simulation clearly demonstrate that indium nanowires are single-crystalline with the tetragonal structure, the growth direction of the nanowires is along [100] facet. The UV-Vis absorption spectra showed that indium nanowires display typical transverse resonance of SPR properties. The surfactant (SDS and the pretreatment of Zn substrate play an important role in the growth process. The mechanism of indium nanowires growth is the synergic effect of treated Zn substrate (hard template and SDS (soft template.

  18. Solvent extraction applied to the recovery of heavy metals from galvanic sludge.

    Science.gov (United States)

    Silva, J E; Paiva, A P; Soares, D; Labrincha, A; Castro, F

    2005-04-11

    In this study, a hydrometallurgical treatment involving the solvent extraction and recovery of some heavy metals from a sulphuric acid leach solution of galvanic sludge, using di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and bis-(2,4,4-trimethylpentyl)-phosphinic acid (Cyanex 272), both diluted in kerosene, has been investigated. The preliminary tests revealed the necessity to remove other metal species than zinc and nickel, contained in the leach solution, and therefore, processes to cement copper and precipitate chromium were then applied to finally obtain a Zn and Ni pregnant solution prior to solvent extraction. For the experimental conditions studied, Cyanex 272 showed a good recovery of Zn after the stripping stage using H2SO4, but D2EHPA effectively promoted a higher Zn extraction than Cyanex 272 did. The dependence of the solvent extraction method on variables such as pH, contact time and concentration of extractant, as well as the effect of different concentrations of sulphuric acid on stripping, are discussed. The discussion also includes the previous conditions developed to separate the main interfering metallic species from the leach solution in order to improve the extraction and recovery of zinc by solvent extraction. The final objective has been to achieve a solution as pure as possible to recover nickel sulphate.

  19. Effects of galvanic vestibular stimulation on visual memory recall and EEG.

    Science.gov (United States)

    Lee, Jeong-Woo; Lee, Gi-Eun; An, Ji-Hyang; Yoon, Se-Won; Heo, Myoung; Kim, Hwang-Yong

    2014-09-01

    [Purpose] This study aimed to examine the effects of galvanic vestibular stimulation (GVS) on visual memory recall and EEG. [Subjects and Methods] In the present study, 42 adults were selected and divided equally into two groups of 21 adults, the GVS group and the Sham group. The error rate was calculated as a percentage based on the total number of errors in the answers to 24 questions after stimulation, while the reaction time was measured in intervals between the time the questions were asked and the time it took the subjects to answer the questions. EEG data were obtained by attaching electrodes to the Fz, Cz, and Pz points during the question and answer phase. [Results] The error rate showed statistically significant differences in the interaction involving the time of response and group. The reaction time showed no statistically significant differences in the interaction involving the time of response and group. When relative band power parameters were analyzed, alpha waves showed no statistically significant differences in the interaction involving the time of response and group, but only the Fz area of beta waves showed statistically significant differences in the interaction involving the time of response and group. [Conclusion] GVS may improve visual memory recall in relation to a flower, a person, an animal, or a building.

  20. Asymmetry of balance responses to monaural galvanic vestibular stimulation in subjects with vestibular schwannoma.

    Science.gov (United States)

    Welgampola, Miriam S; Ramsay, Elijane; Gleeson, Michael J; Day, Brian L

    2013-09-01

    We investigated the potential of galvanic vestibular stimulation (GVS) to quantify lateralised asymmetry of the vestibulospinal pathways by measuring balance responses to monaural GVS in 10 subjects with vestibular schwannoma and 22 healthy control subjects. Subjects standing without vision were stimulated with 3 s, 1 mA direct current stimuli delivered monaurally. The mean magnitude and direction of the evoked balance responses in the horizontal plane were measured from ground-reaction forces and from displacement and velocity of the trunk. Vestibular-evoked myogenic potentials (VEMPs) to 500 Hz air and bone-conducted tones were also recorded. In healthy subjects, the magnitudes of the force, velocity and displacement responses were not significantly different for left compared to right ear stimulation. Their individual asymmetry ratios were always vestibular schwannoma had significantly smaller force, velocity and displacement responses to stimulation of the affected compared with non-affected ear. Their mean asymmetry ratios were significantly elevated for all three measures (41.2 ± 10.3%, 40.3 ± 15.1% and 21.9 ± 14.6%). Asymmetry ratios of balance responses to monaural GVS provide a quantitative and clinically applicable lateralising test of the vestibulospinal pathways. This method offers a more clinically relevant measure of standing balance than existing vestibular function tests which assess only vestibuloocular and vestibulocollic pathways. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  1. Noisy galvanic vestibular stimulation induces a sustained improvement in body balance in elderly adults.

    Science.gov (United States)

    Fujimoto, Chisato; Yamamoto, Yoshiharu; Kamogashira, Teru; Kinoshita, Makoto; Egami, Naoya; Uemura, Yukari; Togo, Fumiharu; Yamasoba, Tatsuya; Iwasaki, Shinichi

    2016-11-21

    Vestibular dysfunction causes postural instability, which is prevalent in the elderly. We previously showed that an imperceptible level of noisy galvanic vestibular stimulation (nGVS) can improve postural stability in patients with bilateral vestibulopathy during the stimulus, presumably by enhancing vestibular information processing. In this study, we investigated the after-effects of an imperceptible long-duration nGVS on body balance in elderly adults. Thirty elderly participants underwent two nGVS sessions in a randomised order. In Session 1, participants received nGVS for 30 min twice with a 4-h interval. In Session 2, participants received nGVS for 3 h. Two-legged stance tasks were performed with eyes closed while participants stood on a foam rubber surface, with and without nGVS, and parameters related to postural stability were measured using posturography. In both sessions, the postural stability was markedly improved for more than 2 h after the cessation of the stimulus and tended to decrease thereafter. The second stimulation in Session 1 caused a moderate additional improvement in body balance and promoted the sustainability of the improvement. These results suggest that nGVS can lead to a postural stability improvement in elderly adults that lasts for several hours after the cessation of the stimulus, probably via vestibular neuroplasticity.

  2. Design of PdAg Hollow Nanoflowers through Galvanic Replacement and Their Application for Ethanol Electrooxidation.

    Science.gov (United States)

    Bin, Duan; Yang, Beibei; Zhang, Ke; Wang, Caiqin; Wang, Jin; Zhong, Jiatai; Feng, Yue; Guo, Jun; Du, Yukou

    2016-11-07

    In this study, galvanic replacement provides a simple route for the synthesis of PdAg hollow nanoflower structures by using the Ag-seeds as sacrificial templates in the presence of l-ascorbic acid (reductant) and CTAC (capping agent). Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and EDS mapping were used to characterize the as-prepared PdAg hollow nanoflower catalysts, where they were alloyed nanoflower structures with hollow interiors. By maneuvering the Pd/Ag ratio, we found that the as-prepared Pd 1 Ag 3 hollow nanoflower catalysts had the optimized performance for catalytic activity toward ethanol oxidation reaction. Moreover, these as-prepared PdAg hollow nanoflower catalysts exhibited noticeably higher electrocatalytic activity as compared to pure Pd and commercial Pd/C catalysts due to the alloyed Ag-Pd composition as well as the hollow nanoflower structures. It is anticipated that this work provides a rational design of other architecturally controlled bimetallic nanocrystals for application in fuel cells. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Size Controlled Synthesis of Tellurium Nanorices by Galvanic Displacement Reaction of Aluminum

    International Nuclear Information System (INIS)

    Wu, Tingjun; Myung, Lawrence Youngjae; Zhang, Miluo; Lee, Kyu-Hwan; Lee, Yeheun Laura; Lim, Hyo-Ryong; Kim, Bum Sung; Choa, Yong-Ho; Myung, Nosang V.

    2015-01-01

    ABSTRACT: Tellurium nanostructures were synthesized by galvanic displacement reaction (GDR) of aluminum in an alkaline solution containing TeO 3 2− ions. Due to negative redox potential of Al/AlO 2 − (i.e., −2.50 V vs. sat. Ag/AgCl), TeO 3 2− (+IV) can be reduced to Te 2 2− (-I) and Te 2− (-II), which resulted in the deposition of Te (0) nanostructures in the solution via chemical reaction between Te 2 2− or Te 2− and TeO 3 2− . The deposition mechanism led to the formation of unique “rice-like” nanostructures in the solution instead of branched structures on the substrate. The sharp tips of the “rice-like” nanostructures may be attributed to the high density of surface charges at the tips. The morphology, diameter and aspect ratio of Te “rice-like” nanostructures were altered by the TeO 3 2− concentration, solution pH, reaction time and the reaction temperature. Electrochemical analytical methods, including open circuit potential (OCP) and linear polarizations (LPs), were used to investigate the reaction mechanisms. The enhancement of piezoelectric constant (d 11 ) of nanorices at small diameter was probably due to a flexoelectric effect

  4. Central adaptation to repeated galvanic vestibular stimulation: implications for pre-flight astronaut training.

    Directory of Open Access Journals (Sweden)

    Valentina Dilda

    Full Text Available Healthy subjects (N = 10 were exposed to 10-min cumulative pseudorandom bilateral bipolar Galvanic vestibular stimulation (GVS on a weekly basis for 12 weeks (120 min total exposure. During each trial subjects performed computerized dynamic posturography and eye movements were measured using digital video-oculography. Follow up tests were conducted 6 weeks and 6 months after the 12-week adaptation period. Postural performance was significantly impaired during GVS at first exposure, but recovered to baseline over a period of 7-8 weeks (70-80 min GVS exposure. This postural recovery was maintained 6 months after adaptation. In contrast, the roll vestibulo-ocular reflex response to GVS was not attenuated by repeated exposure. This suggests that GVS adaptation did not occur at the vestibular end-organs or involve changes in low-level (brainstem-mediated vestibulo-ocular or vestibulo-spinal reflexes. Faced with unreliable vestibular input, the cerebellum reweighted sensory input to emphasize veridical extra-vestibular information, such as somatosensation, vision and visceral stretch receptors, to regain postural function. After a period of recovery subjects exhibited dual adaption and the ability to rapidly switch between the perturbed (GVS and natural vestibular state for up to 6 months.

  5. Diffuse layer effects on the current in galvanic cells containing supporting electrolyte

    International Nuclear Information System (INIS)

    Soestbergen, M. van

    2010-01-01

    We study the effect of an inert supporting electrolyte on the steady-state ionic current through galvanic cells by solving the full Poisson-Nernst-Planck transport equation coupled to the generalized Frumkin-Butler-Volmer boundary equation for the electrochemical charge transfer at the electrodes. Consequently, the model presented here allows for non-zero space charge densities locally at the electrodes, thus extending the frequently used models based on the local electroneutrality condition by including diffuse layer (DL) effects. This extension is necessary since the DLs determine the ion concentration and electrical field at the reaction planes, which uniquely determine the charge transfer at the electrodes. In this work we present numerical results for systems which contain added inert supporting electrolyte using finite element discretization and compare those with semi-analytical results obtained using singular perturbation theory (limit of negligibly thin DLs). In case of negligibly thin DLs the presence of supporting electrolyte will introduce a limiting current below the classical diffusion-limiting current. Just as for systems without supporting electrolyte, the supporting electrolyte induced limiting current formally does not occur for systems having non-negligibly thin double DLs. For thin, however still finite, double layers this limit can still be seen as a steepening of the polarization curve for current vs. voltage.

  6. Assessment of gold exposure and contamination in galvanizing workplace by neutron activation analysis

    International Nuclear Information System (INIS)

    Menezes, M.A.B.C.; Amaral, A.M.; Maia, E.C.P.; Albinati, C.C.B.

    2007-01-01

    Gold is not included in the current list of elements considered essential to humans and there are many controversies related to its toxicity. According to the chemical characteristics of the element, Au 1+ is favored for binding at sites with S donor, such as sulfhydryl group (-SH) in proteins in biological systems. This tendency raises the possibility of health-related risk, mainly linked to a long-term exposure to high and low levels of gold. This paper highlights the determination of gold by instrumental neutron activation analysis (INAA) during the assessment of exposure levels to metals and possible workers' contamination in three galvanizing factories applying the same processes. This assessment is aimed at giving support to Worker's Health Awareness Program of the Municipal Department of Health of Belo Horizonte, Minas Gerais, Brazil. INAA, mix of k 0 and monostandard methods was applied to air filter, hair and toenail samples, and to urine samples. Solvent extraction of gold was carried out followed by comparative INAA. The results revealed that gold was present in all matrixes, indicating the exposure in the workplace and suggesting endogenous contamination. Is gold playing a role as a toxic element? (author)

  7. Effect of noisy galvanic vestibular stimulation on center of pressure sway of static standing posture.

    Science.gov (United States)

    Inukai, Yasuto; Otsuru, Naofumi; Masaki, Mitsuhiro; Saito, Kei; Miyaguchi, Shota; Kojima, Sho; Onishi, Hideaki

    The vestibular system is involved in the control of standing balance. Galvanic vestibular stimulation (GVS) is a noninvasive technique that can stimulate the vestibular system. In recent years, noisy GVS (nGVS) using noise current stimulation has been attempted, but it has not been clarified whether it affects postural sway in open-eye standing. The purpose of this study was to clarify the influence of nGVS on the center of pressure (COP) sway measurement in open-eye standing postural control and identify the responders of nGVS. nGVS (0.1-640 Hz) was delivered at 0.4 and 1.0 mA over the bipolar mastoid. COP sway root mean square area, sway path length, medio-lateral (ML) mean velocity, and antero-posterior (AP) mean velocity before and during nGVS in an open-eye standing posture was measured. nGVS at 0.4 and 1.0 mA significantly reduced sway path length, mean velocity. The stimulation effect of nGVS was also large in subjects with a long sway path. For subjects with high COP sway of Baseline, nGVS was effective even with stimulation for a short duration (5 s). These findings suggest that nGVS improves postural sway in an open-eye standing posture among young subjects. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Galvanic corrosion of lead coupled with titanium for nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Mani Mathew, P.; Krueger, P.A.

    1989-01-01

    In the Canadian Nuclear Fuel Waste Management Program, metals and alloys with low melting points are being evaluated for their potential application as cast matrices within used-fuel immobilization containers. This paper describes studies of galvanic corrosion between lead, candidate matrix metal and ASTM Grade-2 titanium, a candidate container-shell material. The studies were conducted under conditions that simulate a breached disposal container surrounded by a bentonite/sand mixture and emplaced in a granitic rock formation at a depth of 500-1000 m. The fractional factorial statistical design of Box Behnken was used in the tests, which covered a wide range of potential conditions that could occur in a nuclear-waste disposal vault. Test temperatures ranged from 293 to 423 K. Ionic strength and oxygen content of the simulated groundwater varied from 0.0015 to 1.37 mol and 0.02 to 8.0 mg/l, respectively. A mathematical expression was derived for the lead corrosion rates as a function of the independent variables: temperature, ionic strength, and oxygen content. This expression was used to calculate the lifetime of the additional barrier that a 25-mm thick lead layer could provide to a titanium container that eventually perforates by erosion. The results show that at least 860 years of additional barrier life could be provided by the lead matrix

  9. Fusion Framework for Emotional Electrocardiogram and Galvanic Skin Response Recognition: Applying Wavelet Transform

    Directory of Open Access Journals (Sweden)

    Atefeh Goshvarpour

    2016-09-01

    Full Text Available Introduction To extract and combine information from different modalities, fusion techniques are commonly applied to promote system performance. In this study, we aimed to examine the effectiveness of fusion techniques in emotion recognition. Materials and Methods Electrocardiogram (ECG and galvanic skin responses (GSR of 11 healthy female students (mean age: 22.73±1.68 years were collected while the subjects were listening to emotional music clips. For multi-resolution analysis of signals, wavelet transform (Coiflets 5 at level 14 was used. Moreover, a novel feature-level fusion method was employed, in which low-frequency sub-band coefficients of GSR signals and high-frequency sub-band coefficients of ECG signals were fused to reconstruct a new feature. To reduce the dimensionality of the feature vector, the absolute value of some statistical indices was calculated and considered as input of PNN classifier. To describe emotions, two-dimensional models (four quadrants of valence and arousal dimensions, valence-based emotional states, and emotional arousal were applied. Results The highest recognition rates were obtained from sigma=0.01. Mean classification rate of 100% was achieved through applying the proposed fusion methodology. However, the accuracy rates of 97.90% and 97.20% were attained for GSR and ECG signals, respectively. Conclusion Compared to the previously published articles in the field of emotion recognition using musical stimuli, promising results were obtained through application of the proposed methodology.

  10. Influence of surface modified nanoilmenite/amorphous silica composite particles on the thermal stability of cold galvanizing coating

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2018-03-01

    Full Text Available The present approach investigates the use of novel nanoilmenite/amorphous silica composite (NI/AS particles fabricated from ilmenite nanoparticles (FeTiO3 NPs and synthesized amorphous silica grains to improve thermal stability of the cold galvanizing coating. Transmission electron microscopic (TEM images demonstrated that both nanoilmenite and nanocomposite particles were of flaky-like nature and the average diameter of the particles is 20 nm. The lamellar shape of the nanocomposite and spherical nature of Zn-dust particles were illustrated by scanning electron microscopy (SEM micrographs. Different alkyd-based cold galvanizing coating formulations were modified using uniformly dispersing various amounts of the processed nanocomposite particles as a modifier to form some engineering nanocomposite coatings. Thermal stability of the nanocomposite and Zn-dust particles was determined by thermo-gravimetric analysis (TGA. From the obtained results it could be observed that the weight loss (% as a feature of the thermal stability in case of the nanocomposite particles was 2.9 compared to 85.9 for Zn-dust powder grains. Derivative thermo-gravimetric (DTG measurements were done under nitrogen atmosphere for the cured cold galvanizing coating samples heated from room temperature to 1000 °C. The obtained results revealed that the maximum decomposition temperature point in the third degradation step for 6% nanocomposite surface modified cured sample (CG-F was detected at 693 °C and was less value for unmodified conventional cold galvanizing coating (CG-A at 612 °C. The increase in thermal stability with increasing the concentration of nanocomposite particles could be mainly attributed to the interface surface interaction between the nanocomposite particles and alkyd resin matrix in which enhancing the inorganic-organic network stiffness by causing a reduction in the total free spaces and enhancement in the cross-linking density of the cured film

  11. Creep Resistance of VM12 Steel

    Directory of Open Access Journals (Sweden)

    Zieliński A.

    2016-09-01

    Full Text Available This article presents selected material characteristics of VM12 steel used for elements of boilers with super- and ultra-critical steam parameters. In particular, abridged and long-term creep tests with and without elongation measurement during testing and investigations of microstructural changes due to long-term impact of temperature and stress were carried out. The practical aspect of the use of creep test results in forecasting the durability of materials operating under creep conditions was presented. The characteristics of steels with regard to creep tests developed in this paper are used in assessment of changes in functional properties of the material of elements operating under creep conditions.

  12. Magnetic Material Assessment of a Novel Ultra-High Step-Up Converter with Single Semiconductor Switch and Galvanic Isolation for Fuel-Cell Power System

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2017-11-01

    Full Text Available In this paper, a novel step-up converter is proposed, which has the particular features of single semiconductor switch, ultra-high conversion ratio, galvanic isolation, and easy control. Therefore, the proposed converter is suitable for the applications of fuel-cell power system. Coupled inductors and switched capacitors are incorporated in the converter to obtain an ultra-high voltage ratio that is much higher than that of a conventional high step-up converter. Even if the turns ratio of coupled inductor and duty ratio are only to be 1 and 0.5, respectively, the converter can readily achieve a voltage gain of up to 18. Owing to this outstanding performance, it can also be applied to any other low voltage source for voltage boosting. In the power stage, only one active switch is used to handle the converter operation. In addition, the leakage energy of the two couple inductors can be totally recycled without any snubber, which simplifies the control mechanism and improves the conversion efficiency. Magnetic material dominates the conversion performance of the converter. Different types of iron cores are discussed for the possibility to serve as a coupled inductor. A 200 W prototype with 400 V output voltage is built to validate the proposed converter. In measurement, it indicates that the highest efficiency can be up to 94%.

  13. Study of Channel Characteristics for Galvanic-Type Intra-Body Communication Based on a Transfer Function from a Quasi-Static Field Model

    Directory of Open Access Journals (Sweden)

    Min Du

    2012-11-01

    Full Text Available Intra-Body Communication (IBC, which modulates ionic currents over the human body as the communication medium, offers a low power and reliable signal transmission method for information exchange across the body. This paper first briefly reviews the quasi-static electromagnetic (EM field modeling for a galvanic-type IBC human limb operating below 1 MHz and obtains the corresponding transfer function with correction factor using minimum mean square error (MMSE technique. Then, the IBC channel characteristics are studied through the comparison between theoretical calculations via this transfer function and experimental measurements in both frequency domain and time domain. High pass characteristics are obtained in the channel gain analysis versus different transmission distances. In addition, harmonic distortions are analyzed in both baseband and passband transmissions for square input waves. The experimental results are consistent with the calculation results from the transfer function with correction factor. Furthermore, we also explore both theoretical and simulation results for the bit-error-rate (BER performance of several common modulation schemes in the IBC system with a carrier frequency of 500 kHz. It is found that the theoretical results are in good agreement with the simulation results.

  14. Design basis for the copper/steel canister

    Energy Technology Data Exchange (ETDEWEB)

    Bowyer, W.H. [Meadow End Farm, Tilford, Farnham, Surrey (United Kingdom)

    1996-02-01

    The development of the copper/iron canister which has been proposed by SKB for the containment of high level nuclear waste has been studied from the point of view of choice of materials, manufacturing technology and quality assurance. This report describes the observations on progress which have been made between March 1995 and Feb 1996 and the result of further literature studies. A first trial canister has been produced using a fabricated steel liner and an extruded copper tubular, a second one using a fabricated tubular is at an advanced stage. A change from a fabricated steel inner canister to a proposed cast canister has been justified by a criticality argument but the technology for producing a cast canister is at present untried. The microstructure achieved in the extruded copper tubular for the first canister is unacceptable. Similar problems exist with plate used for the fabricated tubular, but some more favourable structures have been achieved already by this route. Seam welding of the first tubular failed through a suspected material problem. The second fabricated tubular welded without difficulty. Welding of lids and bottoms to the copper canister is problematical.There is as yet no satisfactory non destructive test procedures for the parent metal or the welds in the copper canister material, partly due to the coarse grain size which arise in the proposed material processed by the proposed routes. Further studies are also required on crevice corrosion, galvanic attack and stress corrosion cracking in the copper 50 ppm phosphorus alloy. 28 refs.

  15. Design basis for the copper/steel canister

    International Nuclear Information System (INIS)

    Bowyer, W.H.

    1996-02-01

    The development of the copper/iron canister which has been proposed by SKB for the containment of high level nuclear waste has been studied from the point of view of choice of materials, manufacturing technology and quality assurance. This report describes the observations on progress which have been made between March 1995 and Feb 1996 and the result of further literature studies. A first trial canister has been produced using a fabricated steel liner and an extruded copper tubular, a second one using a fabricated tubular is at an advanced stage. A change from a fabricated steel inner canister to a proposed cast canister has been justified by a criticality argument but the technology for producing a cast canister is at present untried. The microstructure achieved in the extruded copper tubular for the first canister is unacceptable. Similar problems exist with plate used for the fabricated tubular, but some more favourable structures have been achieved already by this route. Seam welding of the first tubular failed through a suspected material problem. The second fabricated tubular welded without difficulty. Welding of lids and bottoms to the copper canister is problematical.There is as yet no satisfactory non destructive test procedures for the parent metal or the welds in the copper canister material, partly due to the coarse grain size which arise in the proposed material processed by the proposed routes. Further studies are also required on crevice corrosion, galvanic attack and stress corrosion cracking in the copper 50 ppm phosphorus alloy. 28 refs

  16. DEVELOPMENT OF THE COMPLEX-ALLOYED STEEL OF INCREASED HARDENABILITY, VISCOSITY AND HEAT-RESISTANCE FOR CUTTING PARTS OF HIGH-SPEED INSTRUMENT, OPERATING IN CONDITIONS OF HEATING UP AND DYNAMIC LOADS

    Directory of Open Access Journals (Sweden)

    V. N. Fedulov

    2006-01-01

    Full Text Available The theoretical aspects of development of the complex-alloyed steel compounds for cutting parts of high-speed instrument, particularly influence of alloying elements on its structure and characteristics are considered. It is shown that combined alloying of steel by carbon, chrome, silicon, manganese, vanadium and molybdenum in a certain proportion allows to reach the intended aim, achieving at the same time increase of solidity, impact elasticity and heat stability.

  17. Heat treatments in a conventional steel to reproduce the microstructure of a nuclear grade steel

    International Nuclear Information System (INIS)

    Rosalio G, M.

    2014-01-01

    The ferritic steels used in the manufacture of pressurized vessels of Boiling Water Reactors (BWR) suffer degradation in their mechanical properties due to damage caused by the neutron fluxes of high energy bigger to a Mega electron volt (E> 1 MeV) generated in the reactor core. The materials with which the pressurized vessels of nuclear reactors cooled by light water are built correspond to low alloy ferritic steels. The effect of neutron irradiation on these steels is manifested as an increase in hardness, mechanical strength, with the consequent decrease in ductility, fracture toughness and an increase in temperature of ductile-brittle transition. The life of a BWR is 40 years, its design must be considered sufficient margin of safety because pressure forces experienced during operation, maintenance and testing of postulated accident conditions. It is necessary that under these conditions the vessel to behave ductile and likely to propagate a fracture is minimized. The vessels of light water nuclear reactors have a bainite microstructure. Specifically, the reactor vessels of the nuclear power plant of Laguna Verde (Veracruz, Mexico) are made of a steel Astm A-533, Grade B Class 1. At present they are carrying out some welding tests for the construction of a model of a BWR, however, to use nuclear grade steel such as Astm A-533 to carry out some of the welding tests, is very expensive; perform these in a conventional material provides basic information. Although the microstructure present in the conventional material does not correspond exactly to the degree of nuclear material, it can take of reference. Therefore, it is proposed to conduct a pilot study to establish the thermal treatment that reproduces the microstructure of nuclear grade steel, in conventional steel. The resulting properties of the conventional steel samples will be compared to a JRQ steel, that is a steel Astm A-533, Grade B Class 1, provided by IAEA. (Author)

  18. Production of Austenitic Steel for the LHC Superconducting Dipole Magnets

    CERN Document Server

    Bertinelli, F; Komori, T; Peiro, G; Rossi, L

    2006-01-01

    The austenitic-steel collars are an important component of the LHC dipole magnets, operating at cryogenic temperature under high mechanical stress. The required steel, known as YUS 130S, has been specifically developed for this application by Nippon Steel Corporation (NSC), who was awarded a CERN contract in 1999 for the supply of 11 500 tonnes. In 2005 - after six years of work - the contract is being successfully completed, with final production being ensured since October 2003 by Nippon Steel & Sumikin Stainless Steel Corporation (NSSC). The paper describes the steel properties, its manufacturing and quality control process, organization of production, logistics and contract follow-up. Extensive statistics have been collected relating to mechanical, physical and technological parameters. Specific attention is dedicated to measurements of magnetic permeability performed at cryogenic temperatures by CERN, the equipment used and statistical results. Reference is also made to the resulting precision of the...

  19. Multifaceted effects of noisy galvanic vestibular stimulation on manual tracking behavior in Parkinson’s disease

    Science.gov (United States)

    Lee, Soojin; Kim, Diana J.; Svenkeson, Daniel; Parras, Gabriel; Oishi, Meeko Mitsuko K.; McKeown, Martin J.

    2015-01-01

    Parkinson’s disease (PD) is a neurodegenerative movement disorder that is characterized clinically by slowness of movement, rigidity, tremor, postural instability, and often cognitive impairments. Recent studies have demonstrated altered cortico-basal ganglia rhythms in PD, which raises the possibility of a role for non-invasive stimulation therapies such as noisy galvanic vestibular stimulation (GVS). We applied noisy GVS to 12 mild-moderately affected PD subjects (Hoehn and Yahr 1.5–2.5) off medication while they performed a sinusoidal visuomotor joystick tracking task, which alternated between 2 task conditions depending on whether the displayed cursor position underestimated the actual error by 30% (‘Better’) or overestimated by 200% (‘Worse’). Either sham or subthreshold, noisy GVS (0.1–10 Hz, 1/f-type power spectrum) was applied in pseudorandom order. We used exploratory (linear discriminant analysis with bootstrapping) and confirmatory (robust multivariate linear regression) methods to determine if the presence of GVS significantly affected our ability to predict cursor position based on target variables. Variables related to displayed error were robustly seen to discriminate GVS in all subjects particularly in the Worse condition. If we considered higher frequency components of the cursor trajectory as “noise,” the signal-to-noise ratio of cursor trajectory was significantly increased during the GVS stimulation. The results suggest that noisy GVS influenced motor performance of the PD subjects, and we speculate that they were elicited through a combination of mechanisms: enhanced cingulate activity resulting in modulation of frontal midline theta rhythms, improved signal processing in neuromotor system via stochastic facilitation and/or enhanced “vigor” known to be deficient in PD subjects. Further work is required to determine if GVS has a selective effect on corrective submovements that could not be detected by the current analyses

  20. Galvanic vestibular stimulation improves arm position sense in spatial neglect: a sham-stimulation-controlled study.

    Science.gov (United States)

    Schmidt, Lena; Keller, Ingo; Utz, Kathrin S; Artinger, Frank; Stumpf, Oliver; Kerkhoff, Georg

    2013-01-01

    Disturbed arm position sense (APS) is a frequent and debilitating condition in patients with hemiparesis after stroke. Patients with neglect, in particular, show a significantly impaired contralesional APS. Currently, there is no treatment available for this disorder. Galvanic vestibular stimulation (GVS) may ameliorate neglect and extinction by activating the thalamocortical network. The present study aimed to investigate the immediate effects and aftereffects (AEs; 20 minutes) of subsensory, bipolar GVS (M = 0.6 mA current intensity) on APS in stroke patients with versus without spatial neglect and matched healthy controls. A novel optoelectronic arm position device was developed, enabling the precise measurement of the horizontal APS of both arms. In all, 10 healthy controls, 7 patients with left-sided hemiparesis and left-spatial neglect, and 15 patients with left hemiparesis but without neglect were tested. Horizontal APS was measured separately for both forearms under 4 experimental conditions (baseline without GVS, left-cathodal/right-anodal GVS, right-cathodal/left-anodal GVS, sham GVS). The immediate effects during GVS and the AEs 20 minutes after termination of GVS were examined. Patients with neglect showed an impaired contralateral APS in contrast to patients without neglect and healthy controls. Left-cathodal/right-anodal GVS improved left APS significantly, which further improved into the normal range 20 minutes poststimulation. GVS had no effect in patients without neglect but right-cathodal/left-anodal GVS worsened left APS in healthy participants significantly. GVS can significantly improve the impaired APS in neglect. Multisession GVS can be tested to induce enduring therapeutic effects.

  1. Noisy Galvanic Stimulation Improves Roll-Tilt Vestibular Perception in Healthy Subjects

    Directory of Open Access Journals (Sweden)

    Aram Keywan

    2018-03-01

    Full Text Available It has recently been demonstrated that noisy galvanic vestibular stimulation (nGVS delivered as imperceptible white noise can improve balance control via the induction of stochastic resonance. However, it is unclear whether these balance improvements are accompanied by simultaneous enhancement to vestibular motion perception. In this study, 15 healthy subjects performed 8 quiet-stance tasks on foam with eyes closed at 8 different nGVS amplitudes ranging from 0 mA (baseline to 0.5 mA. The nGVS amplitude that improved balance performance most compared to baseline was assigned as the optimal nGVS amplitude. Optimal nGVS amplitudes could be determined for 13 out of 15 subjects, who were included in the subsequent experimental procedures. The effect of nGVS delivered at the determined optimal intensity on vestibular perceptual thresholds was examined using direction-recognition tasks on a motion platform, testing roll rotations at 0.2, 0.5, and 1.0 Hz, both with active and sham nGVS stimulations. nGVS significantly reduced direction-recognition thresholds compared to the sham condition at 0.5 and 1.0 Hz, while no significant effect of nGVS was found at 0.2 Hz. Interestingly, no correlation was found between nGVS-induced improvements in balance control and vestibular motion perception at 0.5 and 1 Hz, which may suggest different mechanisms by which nGVS affects both modalities. For the first time, we show that nGVS can enhance roll vestibular motion perception. The outcomes of this study are likely to be relevant for the potential therapeutic use of nGVS in patients with balance problems.

  2. Noisy Galvanic Stimulation Improves Roll-Tilt Vestibular Perception in Healthy Subjects.

    Science.gov (United States)

    Keywan, Aram; Wuehr, Max; Pradhan, Cauchy; Jahn, Klaus

    2018-01-01

    It has recently been demonstrated that noisy galvanic vestibular stimulation (nGVS) delivered as imperceptible white noise can improve balance control via the induction of stochastic resonance. However, it is unclear whether these balance improvements are accompanied by simultaneous enhancement to vestibular motion perception. In this study, 15 healthy subjects performed 8 quiet-stance tasks on foam with eyes closed at 8 different nGVS amplitudes ranging from 0 mA (baseline) to 0.5 mA. The nGVS amplitude that improved balance performance most compared to baseline was assigned as the optimal nGVS amplitude. Optimal nGVS amplitudes could be determined for 13 out of 15 subjects, who were included in the subsequent experimental procedures. The effect of nGVS delivered at the determined optimal intensity on vestibular perceptual thresholds was examined using direction-recognition tasks on a motion platform, testing roll rotations at 0.2, 0.5, and 1.0 Hz, both with active and sham nGVS stimulations. nGVS significantly reduced direction-recognition thresholds compared to the sham condition at 0.5 and 1.0 Hz, while no significant effect of nGVS was found at 0.2 Hz. Interestingly, no correlation was found between nGVS-induced improvements in balance control and vestibular motion perception at 0.5 and 1 Hz, which may suggest different mechanisms by which nGVS affects both modalities. For the first time, we show that nGVS can enhance roll vestibular motion perception. The outcomes of this study are likely to be relevant for the potential therapeutic use of nGVS in patients with balance problems.

  3. Multifaceted Effects of Noisy Galvanic Vestibular Stimulation on Manual Tracking Behavior in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Soojin eLee

    2015-02-01

    Full Text Available Parkinson’s disease (PD is a neurodegenerative movement disorder that is characterized clinically by slowness of movement, rigidity, tremor, postural instability, and often cognitive impairments. Recent studies have demonstrated altered cortico-basal ganglia rhythms in PD, which raises the possibility of a role for non-invasive stimulation therapies such as noisy galvanic vestibular stimulation (GVS. We applied noisy GVS to 12 mild-moderately affected PD subjects (Hoehn & Yahr 1.5-2.5 off medication while they performed a sinusoidal visuomotor joystick tracking task, which alternated between 2 task conditions depending on whether the displayed cursor position underestimated the actual error by 30% (‘Better’ or overestimated by 200% (‘Worse’. Either sham or subthreshold, noisy GVS (0.1-10 Hz, 1/f-type power spectrum was applied in pseudorandom order. We used exploratory (Linear Discriminant Analysis with bootstrapping and confirmatory (robust multivariate linear regression methods to determine if the presence of GVS significantly affected our ability to predict cursor position based on target variables. Variables related to displayed error were robustly seen to discriminate GVS in all subjects particularly in the Worse condition. If we considered higher frequency components of the cursor trajectory as noise, the signal-to-noise ratio of cursor trajectory was significantly increased during the GVS stimulation. The results suggest that noisy GVS influenced motor performance of the PD subjects, and we speculate that they were elicited through a combination of mechanisms: enhanced cingulate activity resulting in modulation of frontal midline theta rhythms, improved signal processing in neuromotor system via stochastic facilitation and/or enhanced vigor known to be deficient in PD subjects. Further work is required to determine if GVS has a selective effect on corrective submovements that could not be detected by the current analyses.

  4. The reactor vessel steels

    International Nuclear Information System (INIS)

    Bilous, W.; Hajewska, E.; Szteke, W.; Przyborska, M.; Wasiak, J.; Wieczorkowski, M.

    2005-01-01

    In the paper the fundamental steels using in the construction of pressure vessel water reactor are discussed. The properties of these steels as well as the influence of neutron irradiation on its degradation in the time of exploitation are also done. (authors)

  5. Modern Steel Framed Schools.

    Science.gov (United States)

    American Inst. of Steel Construction, Inc., New York, NY.

    In view of the cost of structural framing for school buildings, ten steel-framed schools are examined to review the economical advantages of steel for school construction. These schools do not resemble each other in size, shape, arrangement or unit cost; some are original in concept and architecture, and others are conservative. Cost and…

  6. Ultrahigh Carbon Steel.

    Science.gov (United States)

    1984-10-01

    Wadsworth, "On the Bulat (Damascus Steels)", Bull. Metals Museum, 4 (1979), pp. 7-23. A 17...34 ’ ." ." ." . .’~.. ." .- .. . .. ,..-.. . . . . -. . . . . .’% ,d ,".. r~~; -W .- & .j2!* . * ~ (8) J. Wadsworth and 0. D. Sherby, "On the Bulat - Damascus Steels Re- visited", Prog. Mater. Sci., 25

  7. Austenitic stainless steels for cryogenic service

    International Nuclear Information System (INIS)

    Dalder, E.N.C.; Juhas, M.C.

    1985-01-01

    Presently available information on austenitic Fe-Cr-Ni stainless steel plate, welds, and castings for service below 77 K are reviewed with the intent (1) of developing systematic relationships between mechanical properties, composition, microstructure, and processing, and (2) of assessing the adequacy of these data bases in the design, fabrication, and operation of engineering systems at 4 K

  8. Effect of Loading Transients on the EAC Crack Growth Behaviour of Low-Alloy RPV Steels under Simulated BWR Operating Conditions (CASTOC WP 3, PSI Tests 3 and 4)

    International Nuclear Information System (INIS)

    Ritter, S.; Seifert, H.-P.

    2003-04-01

    Within the CASTOC-project (5 t h EU FW programme), the environmentally-assisted crack (EAC) growth behaviour of low-alloy reactor pressure vessel (RPV) steels is experimentally investigated under simulated transient and steady-state boiling water reactor (BWR) power operation conditions by six European laboratories. The present report is a summary of the third and fourth test of working package (WP) 3 with loading transients, performed at Paul Scherrer Institut (PSI). Two different low-alloy steels (20 MnMoNi 5 5, 0.015 wt.% S and 22 NiMoCr 3 7, 0.007 wt. %S) were investigated in oxygenated high-temperature, high-purity water (T = 240 o C, DO = 400 ppb) in a daisy chain at two different load ratios (R = 0.8 and 0.2). In the first part of the experiments, asymmetrical saw tooth loading with different rise times Δt R of the load and different loading frequencies were applied. Then the loading conditions were changed to an asymmetrical trapezoid waveform loading (periodical partial unloading, PPU) and the hold time Δt H at maximum load was varied. In the final phase of WP 3 PSI tests 3 and 4 the SCC behaviour was investigated under constant load. With decreasing loading frequency the corrosion fatigue (CF) crack advance per cycle Δa/ΔN EAC of material A increased. Sustained EAC crack growth could be maintained down to low frequencies of 10 -5 Hz. The time-based crack growth rate (CGR) da/dt EAC decreased with decreasing frequency. In material B no effect of the loading frequency could be resolved. Up to a hold time of 1 h at maximum constant load the CGR da/dt EAC seemed to be independent of the hold time. Above hold times of 1 h the CGR decreased and dropped down to CGR values in the range or below the BWR VIP 60 SCC disposition lines. This behaviour was observed in both investigated materials. The cycle-based CGR Δa/ΔN EAC remained approximately constant with increasing hold time. The low-frequency corrosion fatigue (LFCF) CGR Δa/ΔN EAC of material A and B

  9. Surface investigation and tribological mechanism of a sulfate-based lubricant deposited on zinc-coated steel sheets

    Energy Technology Data Exchange (ETDEWEB)

    Timma, Christian, E-mail: christian.timma@thyssenkrupp.com [ThyssenKrupp Steel Europe AG, Technology & Innovation, Kaiser-Wilhelm Str. 100, 47166 Duisburg (Germany); University of Duisburg-Essen, Faculty of Chemistry, CENIDE, Universitätsstraße 7, 45141 Essen (Germany); Lostak, Thomas; Janssen, Stella; Flock, Jörg [ThyssenKrupp Steel Europe AG, Technology & Innovation, Kaiser-Wilhelm Str. 100, 47166 Duisburg (Germany); Mayer, Christian [University of Duisburg-Essen, Faculty of Chemistry, CENIDE, Universitätsstraße 7, 45141 Essen (Germany)

    2016-12-30

    Highlights: • Skin-passed hot-dip galvanized (HDG-) steel sheets were coated with (NH{sub 4}){sub 2}SO{sub 4} in a common roll-coating method. • A formation of (NH{sub 4}){sub 2}Zn(SO{sub 4}) * xH{sub 2}O was observed and the reaction mainly occurred in the skin-passed areas of the surface. • Sulfate coated samples reveal a superior friction behaviour in oil-like conditions compared non-sulfated specimen. - Abstract: Phosphatation is a well-known technique to improve friction and wear behaviour of zinc coated steel, but has a variety of economic and ecologic limitations. In this study an alternative coating based on ammonium sulfate ((NH{sub 4}){sub 2}SO{sub 4}) is applied on skin-passed hot-dip galvanized steel sheets in order to investigate its surface chemical and tribological behaviour in a Pin-on-Disk Tribometer. Raman- and X-ray photoelectron spectroscopic results revealed a formation of ammonium zinc sulfate ((NH{sub 4}){sub 2}Zn(SO{sub 4}){sub 2} * xH{sub 2}O) on the surface, which is primarily located in the skin-passed areas of the steel material. Sulfate coated samples exhibited a superior friction behaviour in Pin-on-Disk Tests using squalane as a model substance for oil-like lubricated conditions and a formation of a thin lubrication film is obtained in the wear track. Squalane acts as a carrier substance for ammonium zinc sulfate, leading to an effective lubrication film in the wear track.

  10. Effect of 1,2,4-triazole on galvanic corrosion between cobalt and copper in CMP based alkaline slurry

    Science.gov (United States)

    Fu, Lei; Liu, Yuling; Wang, Chenwei; Han, Linan

    2018-04-01

    Cobalt has become a new type of barrier material with its unique advantages since the copper-interconnects in the great-large scale integrated circuits (GLSI) into 10 nm and below technical nodes, but cobalt and copper have severe galvanic corrosion during chemical–mechanical flattening. The effect of 1,2,4-triazole on Co/Cu galvanic corrosion in alkaline slurry and the control of rate selectivity of copper and cobalt were investigated in this work. The results of electrochemical experiments and polishing experiments had indicated that a certain concentration of 1,2,4-triazole could form a layer of insoluble and dense passive film on the surface of cobalt and copper, which reduced the corrosion potential difference between cobalt and copper. Meantime, the removal rate of cobalt and copper could be effectively controlled according to demand during the CMP process. When the study optimized slurry was composed of 0.5 wt% colloidal silica, 0.1 %vol. hydrogen peroxide, 0.05 wt% FA/O, 345 ppm 1,2,4-triazole, cobalt had higher corrosion potential than copper and the galvanic corrosion could be reduced effectively when the corrosion potential difference between them decreased to 1 mV and the galvanic corrosion current density reached 0.02 nA/cm2. Meanwhile, the removal rate of Co was 62.396 nm/min, the removal rate of Cu was 47.328 nm/min, so that the removal rate ratio of cobalt and copper was 1.32 : 1, which was a good amendment to the dishing pits. The contact potential corrosion of Co/Cu was very weak, which could be better for meeting the requirements of the barrier CMP. Project supported by the Major National Science and Technology Special Projects (No. 2016ZX02301003-004-007), the Natural Science Foundation of Hebei Province, China (No. F2015202267), and the Outstanding Young Science and Technology Innovation Fund of Hebei University of Technology (No. 2015007).

  11. Influence of the doping type and level on the morphology of porous Si formed by galvanic etching

    Energy Technology Data Exchange (ETDEWEB)

    Pyatilova, O. V., E-mail: 5ilova87@gmail.com; Gavrilov, S. A.; Shilyaeva, Yu. I. [Zelenograd, National Research University of Electronic Technology (MIET) (Russian Federation); Pavlov, A. A. [Russian Academy of Sciences, Institute of Nanotechnology of Microelectronics (Russian Federation); Shaman, Yu. P. [Zelenograd, Scientific-Manufacturing Complex “Technological Centre” MIET (Russian Federation); Dudin, A. A. [Russian Academy of Sciences, Institute of Nanotechnology of Microelectronics (Russian Federation)

    2017-02-15

    The formation of porous silicon (por-Si) layers by the galvanic etching of single-crystal Si samples (doped with boron or phosphorus) in an HF/C{sub 2}H{sub 5}OH/H{sub 2}O{sub 2} solution is investigated. The por-Si layers are analyzed by the capillary condensation of nitrogen and scanning electron microscopy (SEM). The dependences of the morphological characteristics of por-Si (pore diameter, specific surface area, pore volume, and thickness of the pore walls), which determine the por-Si combustion kinetics, on the dopant type and initial wafer resistivity are established.

  12. Analysis and Modeling of the Galvanic Skin Response Spontaneous Component in the context of Intelligent Biofeedback Systems Development

    Science.gov (United States)

    Unakafov, A.

    2009-01-01

    The paper presents an approach to galvanic skin response (GSR) spontaneous component analysis and modeling. In the study a classification of biofeedback training methods is given, importance of intelligent methods development is shown. The INTENS method, which is perspective for intellectualization, is presented. An important problem of biofeedback training method intellectualization - estimation of the GSR spontaneous component - is solved in the main part of the work. Its main characteristics are described; results of GSR spontaneous component modeling are shown. Results of small research of an optimum material for GSR probes are presented.

  13. Aspects of materials handling systems in the steel fabrication environment

    OpenAIRE

    2012-01-01

    M.Ing. This dissertation covers a literature survey of materials handling and plant layout in the steel fabrication environment. It covers some of the elements and principles of materials handling and how they interact with and influence the effective flow of materials in an operation. Some of the current materials handling methods and systems of a specific South African steel fabrication operation are then investigated. By using the information from the literature study, an evaluation is ...

  14. Standard Test Method for Measurement of Hydrogen Embrittlement Threshold in Steel by the Incremental Step Loading Technique

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method establishes a procedure to measure the susceptibility of steel to a time-delayed failure such as that caused by hydrogen. It does so by measuring the threshold for the onset of subcritical crack growth using standard fracture mechanics specimens, irregular-shaped specimens such as notched round bars, or actual product such as fasteners (2) (threaded or unthreaded) springs or components as identified in SAE J78, J81, and J1237. 1.2 This test method is used to evaluate quantitatively: 1.2.1 The relative susceptibility of steels of different composition or a steel with different heat treatments; 1.2.2 The effect of residual hydrogen in the steel as a result of processing, such as melting, thermal mechanical working, surface treatments, coatings, and electroplating; 1.2.3 The effect of hydrogen introduced into the steel caused by external environmental sources of hydrogen, such as fluids and cleaners maintenance chemicals, petrochemical products, and galvanic coupling in an aqueous enviro...

  15. Hydrothermal–galvanic couple synthesis of directionally oriented BaTiO3 thin films on TiN-coated substrates

    International Nuclear Information System (INIS)

    Yang, Chia-Jung; Tsai, Di-You; Chan, Pei-Hsuan; Wu, Chu-Tsun; Lu, Fu-Hsing

    2013-01-01

    BaTiO 3 films were synthesized on TiN-coated Si substrate below 100 °C by a hydrothermal–galvanic couple technique in barium contained alkaline solutions. X-ray diffraction and electron backscatter diffraction results show that the BaTiO 3 thin films were directionally oriented grown on the TiN/Si substrates, i.e., (111) BaTiO 3 over (111) TiN. The surface morphologies revealed that BaTiO 3 nucleated and grew over the TiN surface with a single layer. From kinetic analyses, the growth rates of BaTiO 3 films prepared by the hydrothermal–galvanic couple technique were faster than a hydrothermal method. The galvanic effects were confirmed by investigating the induced currents and energies. The galvanic currents were generated and controlled by both the dissolution of TiN and the formation of BaTiO 3 . The output electric energies increased rapidly with the reaction time and leveled off at the full coverage of BaTiO 3 . - Highlights: • Cubic BaTiO 3 films are synthesized by a hydrothermal–galvanic couple method (HT–GC). • Growth rates of BaTiO 3 films made by HT–GC are faster than a hydrothermal method. • BaTiO 3 films are directionally oriented grown on the TiN/Si substrates. • Galvanic currents are controlled by dissolution of TiN and formation of BaTiO 3

  16. Thermal aging of primary coolant pipe steel

    International Nuclear Information System (INIS)

    Miller, M.K.; Bentley, J.; Brenner, S.S.; Spitznagel, J.A.

    1985-01-01

    The long term mechanical integrity of the pipes used to carry the primary cooling water in a pressurized water nuclear reactor is of the utmost importance for safe operation. A combined atom probe field-ion microscopy (APFIM) and transmission electron microscopy (TEM) study was performed to characterize the microstructure of this cast stainless steel and to determine the changes that occur during long-term low-temperature thermal aging. The material used in this investigation was a commercial CF 8 type stainless. The steel was examined in the as-cast, unaged condition and also after aging for 7500 h at 673K. 3 refs., 4 figs., 2 tabs

  17. Effect of Ultrasonic Nano-Crystal Surface Modification (UNSM) on the Passivation Behavior of Aged 316L Stainless Steel.

    Science.gov (United States)

    Kim, Ki-Tae; Lee, Jung-Hee; Kim, Young-Sik

    2017-06-27

    Stainless steels have good corrosion resistance in many environments but welding or aging can decrease their resistance. This work focused on the effect of aging time and ultrasonic nano-crystal surface modification on the passivation behavior of 316L stainless steel. In the case of slightly sensitized 316L stainless steel, increasing the aging time drastically decreased the pitting potential, increased the passive current density, and decreased the resistance of the passive film, even though aging did not form chromium carbide and a chromium depletion zone. This behavior is due to the micro-galvanic corrosion between the matrix and carbon segregated area, and this shows the importance of carbon segregation in grain boundaries to the pitting corrosion resistance of stainless steel, in addition to the formation of the chromium depletion zone. UNSM (Ultrasonic Nano Crystal Surface Modification)-treatment to the slightly sensitized 316L stainless steel increased the pitting potential, decreased the passive current density, and increased the resistance of the passive film. However, in the case of heavily sensitized 316L stainless steel, UNSM-treatment decreased the pitting potential, increased the passive current density, and decreased the resistance of the passive film. This behavior is due to the dual effects of the UNSM-treatment. That is, the UNSM-treatment reduced the carbon segregation, regardless of whether the stainless steel 316L was slightly or heavily sensitized. However, since this treatment made mechanical flaws in the outer surface in the case of the heavily sensitized stainless steel, UNSM-treatment may eliminate chromium carbide, and this flaw can be a pitting initiation site, and therefore decrease the pitting corrosion resistance.

  18. Fabrication of dendritic silver-coated copper powders by galvanic displacement reaction and their thermal stability against oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yu-Seon [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Farad Materials Co., Ltd., Suwon 16419 (Korea, Republic of); An, Chang Yong; Kannan, Padmanathan Karthick; Seo, Nary [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Zhuo, Kai [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Farad Materials Co., Ltd., Suwon 16419 (Korea, Republic of); Yoo, Tae Kyong [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Chung, Chan-Hwa, E-mail: chchung@skku.edu [School of Chemical Engineering, Sungkyunkwan University, Suwon 16419 (Korea, Republic of); Farad Materials Co., Ltd., Suwon 16419 (Korea, Republic of)

    2016-12-15

    Highlights: • The dendritic silver-coated copper powders with high specific surface area have been prepared using a simple wet chemical reduction process at room temperature. • It is found that the Cu starts to be oxidized into Cu{sub 2}O followed by CuO at elevated temperatures. • The more amount of Ag-coating provides the less oxidation, which confirms that the Ag-shell prevents the Cu-core from oxidation. • The resistivity of dendritic 33.27 wt.% Ag-coated Cu powders was measured to 25.67 μΩ cm after the annealing at 150 °C for 30 min. - Abstract: Two steps of wet chemical processes have been developed for the preparation of core-shell nanostructures of copper and silver, which is a facile and low cost method for the production of large quantity of dendritic powders. First step involves a galvanic displacement reaction with hydrogen evolution which is the motive force of spontaneous electrochemical reaction. To achieve the core-shell structure, silver has been coated on the dendritic copper using the galvanic displacement reaction. The dendritic silver-coated copper powders exhibit high surface-area, excellent conductivity, and good oxidation resistance. It has been found that silver-coated copper powders maintain the electrical conductivity even after annealing at 150 °C for several to tens of minutes, thus it is a promising material and an alternative to pure silver powders in printed electronics application.

  19. Bit error rate estimation for galvanic-type intra-body communication using experimental eye-diagram and jitter characteristics.

    Science.gov (United States)

    Li, Jia Wen; Chen, Xi Mei; Pun, Sio Hang; Mak, Peng Un; Gao, Yue Ming; Vai, Mang I; Du, Min

    2013-01-01

    Bit error rate (BER), which indicates the reliability of communicate channel, is one of the most important values in all kinds of communication system, including intra-body communication (IBC). In order to know more about IBC channel, this paper presents a new method of BER estimation for galvanic-type IBC using experimental eye-diagram and jitter characteristics. To lay the foundation for our methodology, the fundamental relationships between eye-diagram, jitter and BER are first reviewed. Then experiments based on human lower arm IBC are carried out using quadrature phase shift keying (QPSK) modulation scheme and 500 KHz carries frequency. In our IBC experiments, the symbol rate is from 10 Ksps to 100 Ksps, with two transmitted power settings, 0 dBm and -5 dBm. Finally, the BER results were obtained after calculation by experimental data through the relationships among eye-diagram, jitter and BER. These results are then compared with theoretical values and they show good agreement, especially when SNR is between 6 dB to 11 dB. Additionally, these results demonstrate assuming the noise of galvanic-type IBC channel as Additive White Gaussian Noise (AWGN) in previous study is applicable.

  20. Design of steel cylindrical tanks

    OpenAIRE

    Hlastec, Jan

    2012-01-01

    The thesis deals with the area of steel shell structures. Presented is the design process of steel cylindrical tanks using Eurocode standards. I dealt with the plastic limit states and stability limit state of steel shell structures. A program for the calculation of cylindrical steel tanks for the limit state of strength and stability is made in Matlab. The focus of this work is on understanding the design process of cylindrical steel tanks and creating a computer program in Matlab. Create...

  1. Electrochemical synthesis and characterisation of hybrid materials polypyrrole/dodecatungstophosphate as protective agents against steel corrosion

    Science.gov (United States)

    Bonastre Cano, Jose Antonio

    The losses caused by the effect of the corrosion are of the order of 2-3,5% of the GDP of the developed countries or developing only in direct costs, losses in structures or products. This figure doubles by the indirect costs, losses of productivity or demands for delays. Beside the possible losses of human lives, any intent leaded to the decrease of the corrosion in rusty metals is a commendable objective from the point of view of the protection of the environment. Building industry employing reinforced concrete is able to project some structural elements (pillars, wrought, beam, etc.) in principle free of corrosion, assuring during many years the useful life of the work in service. However, the reinforced concrete would be' a perfect solution if the indefinite permanency of the passive state of the steel could be guaranteed. Indeed, although the steel is protected against corrosion due to basic pH which provides the cement, the severe action of saline media or the effect of CO2 can diminish this protection conditions beginning the corrosion in steel elements. Type-p doped conducting polymers, as polypyrrole, are firm candidates to protect carbon steel providing galvanic protection by stabilising the passive layer of Fe oxides initially grown. Doping the polymeric matrix with polioxometalates, concretely phosphotungstate PW12O403-, is a very interesting hypothesis due to their oxidising effect, improving the anodic protection by the hybrid material electrosynthesised on carbon steel substrate. First in the present work, a new method was developed by cyclic voltammetry in LiClO4 + acetonitrile medium in order to diminish the unavoidable oxidation of carbon steel when the electrosyntesis of the hybrid material polypyrrole/PW12O403- is carrying out. The beginning potential of polypyrrole polymerisation is about 0.8 V (vs. Ag/AgCl), a positive potential where oxidation of Fe substrate is high, not allowing the electrodeposition of the hybrid material. On the other

  2. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    Chopra, O.K.; Chung, H.M.

    1985-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450 0 C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the α' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450 0 C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450 0 C. 18 refs., 13 figs

  3. Large steel components of nuclear power stations

    International Nuclear Information System (INIS)

    Nielsen, A.

    1974-12-01

    A broad review is given of the present situation with regard to control of the safety of steel components. To give an impression of the failure of steel constructions in general, the best known accidents of recent years are discussed as well as the measures taken to avoid such occurences in future. In this context, one section deals with the brittle fracture of steel. The concept of accident probability is discussed in connection with the heavy demands made on nuclear plants. This is followed by a review of a number of possibilities for reducing the probability of accidents. An explanation is given of why simple over-sizing is of no use but methods for control during manufacture and operation are. Hereunder the basis for the mechanics of fracture is simply presented to elucidate the connection between defect, load and toughness of steel, since this relationship determines the accident probability. The significance of pressure testing is dealt with. Finally mention is made of a couple of possibilities of evading steel pressure vessels as means of confinement for nuclear energy producing reactions. (author)

  4. Glass Stronger than Steel

    Science.gov (United States)

    Yarris, Lynn

    2011-03-28

    A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of steel or any other known material, has been developed and tested by a collaboration of researchers from Berkeley Lab and Caltech.

  5. Structural amorphous steels

    International Nuclear Information System (INIS)

    Lu, Z.P.; Liu, C.T.; Porter, W.D.; Thompson, J.R.

    2004-01-01

    Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist's dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed

  6. Steel Strapping Evaluation

    National Research Council Canada - National Science Library

    Haas, Bradley

    1996-01-01

    ... (ARDEC) to perform salt-fog accelerated-aging testing on 1 - 1/4-inch steel strapping to determine whether Delta, style III, painted seals are a suitable alternative to currently utilized seals...

  7. Metallurgy: Printing steels

    Science.gov (United States)

    Todd, Iain

    2018-01-01

    Additive manufacturing has been used to fabricate a common stainless steel, which imparts a unique microstructure to this material, making it stronger and more ductile than that produced with conventional methods.

  8. Current measurement method for characterization of fast switching power semiconductors with Silicon Steel Current Transformer

    DEFF Research Database (Denmark)

    Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig

    2015-01-01

    , it compensates the mechanical size limitations of the Pearson current monitor. Finally, experimental studied are carried out with both discrete Silicon Carbide (SiC) MOSFET and high current (1000A) Silicon (Si) IGBT power modules. The experimental results validate the effectiveness of the proposed method.......This paper proposes a novel current measurement method with Silicon Steel Current Transformer (SSCT) for the characterization of fast switching power semiconductors. First, the existing current sensors for characterization of fast switching power semiconductors are experimentally evaluated...... regarding three essential qualities: high bandwidth, suitable physical size, and galvanic isolation. Then, the proposed current measurement method with SSCT is mathematically analyzed, which proves that the proposed method has the capability of measuring fast switching current. Simultaneously...

  9. An electroplated copper–silver alloy as antibacterial coating on stainless steel

    DEFF Research Database (Denmark)

    Ciacotich, Nicole; Din, Rameez Ud; Sloth, Jens Jørgen

    2018-01-01

    electroplated with a copper-silver alloy with the aim of developing antibacterial surfaces for the medical and health care sector. The microstructural characterization showed a porous microstructure of electroplated copper-silver coating and a homogeneous alloy with presence of interstitial silver. The copper-silver......Transfer and growth of pathogenic microorganisms must be prevented in many areas such as the clinical sector. One element of transfer is the adhesion of pathogens to different surfaces and the purpose of the present study was to develop and investigate the antibacterial efficacy of stainless steel...... alloy coating showed active corrosion behavior in chloride-containing environments. ICP-MS measurements revealed a selective and localized dissolution of copper ions in wet conditions due to its galvanic coupling with silver. No live bacteria adhered to the copper-silver surfaces when exposed...

  10. Complex approach mechanical properties and formability assessment of selected deep-drawing steels

    Directory of Open Access Journals (Sweden)

    J. Štaba

    2009-07-01

    Full Text Available The paper analyses the properties of deep-drawing sheets of three grades (Re = 320 to 475 MPa, surface-treated with hot-dip galvanizing, made of microalloyed steels. Deformation properties are assessed using tensile tests, technological Erichsen or cupping tests. These characteristics, as well as the behaviour of the surface layer, are also investigated under dynamic conditions (modified Erichsen test using a drop tester, or using flat bending fatigue tests. Using microscopic analysis the deformation properties of the surface layer are evaluated. The results show the compactness of the surface layer, high deformation characteristics, as well as fatigue properties of the investigated deep-drawing materials, suitable for application in the automotive industry.

  11. Life after Steel

    Science.gov (United States)

    Mangan, Katherine

    2013-01-01

    Bobby Curran grew up in a working-class neighborhood in Baltimore, finished high school, and followed his grandfather's steel-toed bootprints straight to Sparrows Point, a 3,000-acre sprawl of industry on the Chesapeake Bay. College was not part of the plan. A gritty but well-paying job at the RG Steel plant was Mr. Curran's ticket to a secure…

  12. High Nitrogen Stainless Steel

    Science.gov (United States)

    2011-07-19

    crack growth (FCG) test (ASTM E 647-95a) - square bar specimen of 0.4x0.4x2.8 in. in L-orientation with a Charpy notch at the mid- length for SCC...Hydrogen Embrittlement in Steel by the Increment Loading Technique. Fractography: After the stress-life fatigue tests , the fracture surface morphology...NAWCADPAX/TR-2011/162 HIGH NITROGEN STAINLESS STEEL by E. U. Lee R. Taylor 19 July 2011 Approved for

  13. Ferrium M54 Steel

    Science.gov (United States)

    2015-03-18

    coated specimens of Ferrium M54 steel were subjected to electrochemical measurement, microstructure examination, mechanical testing in air, fatigue...counsel on fatigue crack growth testing . NAWCADPAX/TIM-2014/292 1 INTRODUCTION High strength steels developed in the 1940’s and 1950’s... Charpy notch at the mid-length for SCC test under four-point bending (ASTM F 1624) - flat plate specimen of 4 x 4 x 1/8 in. for electrochemical

  14. A comparison of the tribological behaviour of steel/steel, steel/DLC and DLC/DLC contact when lubricated with mineral and biodegradable oils

    OpenAIRE

    Kalin, Mitjan; Vižintin, Jože

    2015-01-01

    Diamond-like carbon (DLC) coatings, which can nowadays be applied to many highly loaded mechanical components, sometimes need to operate under lubricated conditions. It is reasonable to expect that in steel/DLC contacts, at least the steel counter body will behave according to conventional lubrication mechanisms and will interact with lubricants and additives in the contact. However, in DLC/DLC contacts, such mechanisms are still unclear. For example, the "inertness" of DLC coatings raises se...

  15. Low-temperature creep of austenitic stainless steels

    Science.gov (United States)

    Reed, R. P.; Walsh, R. P.

    2017-09-01

    Plastic deformation under constant load (creep) in austenitic stainless steels has been measured at temperatures ranging from 4 K to room temperature. Low-temperature creep data taken from past and unreported austenitic stainless steel studies are analyzed and reviewed. Creep at cryogenic temperatures of common austenitic steels, such as AISI 304, 310 316, and nitrogen-strengthened steels, such as 304HN and 3116LN, are included. Analyses suggests that logarithmic creep (creep strain dependent on the log of test time) best describe austenitic stainless steel behavior in the secondary creep stage and that the slope of creep strain versus log time is dependent on the applied stress/yield strength ratio. The role of cold work, strain-induced martensitic transformations, and stacking fault energy on low-temperature creep behavior is discussed. The engineering significance of creep on cryogenic structures is discussed in terms of the total creep strain under constant load over their operational lifetime at allowable stress levels.

  16. Articles comprising ferritic stainless steels

    Science.gov (United States)

    Rakowski, James M.

    2016-06-28

    An article of manufacture comprises a ferritic stainless steel that includes a near-surface region depleted of silicon relative to a remainder of the ferritic stainless steel. The article has a reduced tendency to form an electrically resistive silica layer including silicon derived from the steel when the article is subjected to high temperature oxidizing conditions. The ferritic stainless steel is selected from the group comprising AISI Type 430 stainless steel, AISI Type 439 stainless steel, AISI Type 441 stainless steel, AISI Type 444 stainless steel, and E-BRITE.RTM. alloy, also known as UNS 44627 stainless steel. In certain embodiments, the article of manufacture is a fuel cell interconnect for a solid oxide fuel cell.

  17. Carbon steel corrosion induced by sulphate-reducing bacteria in artificial seawater: electrochemical and morphological characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Paula, Mariana Silva de; Goncalves, Marcia Monteiro Machado; Rola, Monick Alves da Cruz; Maciel, Diana Jose; Senna, Lilian Ferreira de; Lago, Dalva Cristina Baptista do, E-mail: sdp.mari@gmail.com, E-mail: marciamg@uerj.br, E-mail: monickcruz@yahoo.com.br, E-mail: dijmaciel@gmail.com, E-mail: lsenna@uerj.br, E-mail: dalva@uerj.br [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Instituto de Quimica

    2016-10-15

    In this work, the corrosion behavior of carbon steel AISI 1020 was evaluated in artificial seawater in the presence of mixed sulfate-reducing bacteria (SRB) culture isolated from the rust of a pipeline. The corrosion evaluation was performed by electrochemical techniques (open circuit potential (E{sub ocp}), polarization curves and electrochemical impedance spectroscopy (EIS)), while the formation of a biofilm and corrosion products were observed by scanning electron microscopy (SEM) and X-ray energy dispersive spectroscopy (EDS). The presence of SRB in the medium shifted the open circuit potential to more positive values and increased the corrosion rate of the steel. Electrochemical and morphological techniques confirmed the presence of a biofilm on the steel surface. EDS spectra data showed the presence of sulfur in the corrosion products. After removing the biofilm, localized corrosion was observed on the surface, confirming that localized corrosion had occurred. The biogenic sulfide may lead to the formation of galvanic cells and contributes to cathodic depolarization. (author)

  18. A gauged finite-element potential formulation for accurate inductive and galvanic modelling of 3-D electromagnetic problems

    Science.gov (United States)

    Ansari, S. M.; Farquharson, C. G.; MacLachlan, S. P.

    2017-07-01

    In this paper, a new finite-element solution to the potential formulation of the geophysical electromagnetic (EM) problem that explicitly implements the Coulomb gauge, and that accurately computes the potentials and hence inductive and galvanic components, is proposed. The modelling scheme is based on using unstructured tetrahedral meshes for domain subdivision, which enables both realistic Earth models of complex geometries to be considered and efficient spatially variable refinement of the mesh to be done. For the finite-element discretization edge and nodal elements are used for approximating the vector and scalar potentials respectively. The issue of non-unique, incorrect potentials from the numerical solution of the usual incomplete-gauged potential system is demonstrated for a benchmark model from the literature that uses an electric-type EM source, through investigating the interface continuity conditions for both the normal and tangential components of the potential vectors, and by showing inconsistent results obtained from iterative and direct linear equation solvers. By explicitly introducing the Coulomb gauge condition as an extra equation, and by augmenting the Helmholtz equation with the gradient of a Lagrange multiplier, an explicitly gauged system for the potential formulation is formed. The solution to the discretized form of this system is validated for the above-mentioned example and for another classic example that uses a magnetic EM source. In order to stabilize the iterative solution of the gauged system, a block diagonal pre-conditioning scheme that is based upon the Schur complement of the potential system is used. For all examples, both the iterative and direct solvers produce the same responses for the potentials, demonstrating the uniqueness of the numerical solution for the potentials and fixing the problems with the interface conditions between cells observed for the incomplete-gauged system. These solutions of the gauged system also

  19. Response of ferritic steels to nonsteady loading at elevated temperatures

    International Nuclear Information System (INIS)

    Swindeman, R.W.

    1984-01-01

    High-temperature operating experience is lacking in pressure vessel materials that have strength levels above 586 MPa. Because of their tendency toward strain softening, we have been concerned about their behavior under nonsteady loading. Testing was undertaken to explore the extent of softening produced by monotonic and cyclic strains. The specific materials included bainitic 2 1/4Cr-1Mo steel, a micro-alloyed version of 2 1/4Cr-1Mo steel, a micro-alloyed version of 2 1/4Cr-1Mo steel containing vanadium, titanium, and boron, and a martensitic 9Cr-1Mo-V-Nb steel. Tests included tensile, creep, variable stress creep, relaxation, strain cycling, stress cycling, and non-isothermal creep ratchetting experiments. We found that these steels had very low uniform elongation and exhibited small strains to the onset of tertiary creep compared to annealed 2 1/4Cr-1Mo steel. Repeated relaxation test data also indicated a limited capacity for strain hardening. Reversal strains produced softening. The degree of softening increased with increased initial strength level. We concluded that the high strength bainitic and martensitic steels should perform well when used under conditions where severe cyclic operation does not occur

  20. PROTECTIVE LAYERS OF IRON AND NICKEL ALUMINIDES ON STEEL

    Directory of Open Access Journals (Sweden)

    Milena Voděrová

    2013-07-01

    Full Text Available Intermediary phases Ni-Al and Fe-Al are promising materials due to their superior properties such as hardness and good resistance against oxidation at high temperatures. Moreover, Fe-Al phases are resistant in sulphur - containing atmospheres. Because of these characteristics, the above mentioned intermetallic phases seem to be prospective for the use in many technical applications such as energetics, chemical or automotive industry in a form of a bulk material or coatings. Presently, the protective aluminide layer is usually prepared by thermal spraying. Nevertheless, this method is not suitable for complex-shaped components. Therefore, the aim of this work was to find an alternative way to prepare layers consisting of nickel or iron aluminides by other technique than thermal spraying. At first, carbon steel samples were coated using galvanic or electroless nickel plating. Coated samples were subsequently submerged into molten aluminium at various temperatures and process durations. The influence of the temperature and duration on the intermetallic phase growth was studied by scanning electron and light microscopy. Thickness and microhardness of the intermetallic layer was also measured.

  1. PROTECTIVE LAYERS OF IRON AND NICKEL ALUMINIDES ON STEEL

    Directory of Open Access Journals (Sweden)

    Milena Voderova

    2013-05-01

    Full Text Available Intermediary phases Ni-Al and Fe-Al are promising materials due to their superior properties such as hardness and good resistance against oxidation at high temperatures. Moreover, Fe-Al phases are resistant in sulphur - containing atmospheres. Because of these characteristics, the above mentioned intermetallic phases seem to be prospective for the use in many technical applications such as energetics, chemical or automotive industry in a form of a bulk material or coatings. Presently, the protective aluminide layer is usually prepared by thermal spraying. Nevertheless, this method is not suitable for complex-shaped components. Therefore, the aim of this work was to find an alternative way to prepare layers consisting of nickel or iron aluminides by other technique than thermal spraying. At first, carbon steel samples were coated using galvanic or electroless nickel plating. Coated samples were subsequently submerged into molten aluminium at various temperatures and process durations. The influence of the temperature and duration on the intermetallic phase growth was studied by scanning electron and light microscopy. Thickness and microhardness of the intermetallic layer was also measured.

  2. Steel fiber reinforced concrete

    International Nuclear Information System (INIS)

    Baloch, S.U.

    2005-01-01

    Steel-Fiber Reinforced Concrete is constructed by adding short fibers of small cross-sectional size .to the fresh concrete. These fibers reinforce the concrete in all directions, as they are randomly oriented. The improved mechanical properties of concrete include ductility, impact-resistance, compressive, tensile and flexural strength and abrasion-resistance. These uniqlte properties of the fiber- reinforcement can be exploited to great advantage in concrete structural members containing both conventional bar-reinforcement and steel fibers. The improvements in mechanical properties of cementitious materials resulting from steel-fiber reinforcement depend on the type, geometry, volume fraction and material-properties of fibers, the matrix mix proportions and the fiber-matrix interfacial bond characteristics. Effects of steel fibers on the mechanical properties of concrete have been investigated in this paper through a comprehensive testing-programme, by varying the fiber volume fraction and the aspect-ratio (Lid) of fibers. Significant improvements are observed in compressive, tensile, flexural strength and impact-resistance of concrete, accompanied by marked improvement in ductility. optimum fiber-volume fraction and aspect-ratio of steel fibers is identified. Test results are analyzed in details and relevant conclusions drawn. The research is finally concluded with future research needs. (author)

  3. Integrity of Magnox reactor steel pressure vessels

    International Nuclear Information System (INIS)

    Flewitt, P.E.J.; Williams, G.H.; Wright, M.B.

    1993-01-01

    The background to the safety assessment of the steel reactor pressure vessels for Magnox power stations is reviewed. The evolved philosophy adopted for the 1991 safety cases prepared for the continued operation of four Magnox power stations operated by Nuclear Electric plc is described together with different aspects of the multielement integrity argument. The main revisions to the mechanical property data are addressed together with the assessment methodology adopted and their implications for the overall integrity argument formulated for the continued safe operation of these reactor pressure vessels are discussed. (author)

  4. Integrity of Magnox reactor steel pressure vessels

    International Nuclear Information System (INIS)

    Flewitt, P.E.J.; Williams, G.H.; Wright, M.B.

    1992-01-01

    The background to the safety assessment of the steel reactor pressure vessels for Magnox power stations is reviewed. The evolved philosophy adopted for the 1991 safety cases prepared for the continued operation of four Magnox power stations operated by Nuclear Electric plc is described, together with different aspects of the multi-legged integrity argument. The main revisions to the materials mechanical property data are addressed together with the assessment methodology adopted and their implications for the overall integrity argument formulated for the continued safe operation of these reactor pressure vessels. (author)

  5. Tailoring galvanic replacement reaction for the preparation of Pt/Ag bimetallic hollow nanostructures with controlled number of voids.

    Science.gov (United States)

    Zhang, Weiqing; Yang, Jizheng; Lu, Xianmao

    2012-08-28

    Here we report the synthesis of Pt/Ag bimetallic nanostructures with controlled number of void spaces via a tailored galvanic replacement reaction (GRR). Ag nanocubes (NCs) were employed as the template to react with Pt ions in the presence of HCl. The use of HCl in the GRR caused rapid precipitation of AgCl, which grew on the surface of Ag NCs and acted as a removable secondary template for the deposition of Pt. The number of nucleation sites for AgCl was tailored by controlling the amount of HCl added to the Ag NCs or by introducing PVP to the reaction. This strategy led to the formation of Pt/Ag hollow nanoboxes, dimers, multimers, or popcorn-shaped nanostructures consisting of one, two, or multiple hollow domains. Due to the presence of large void space and porous walls, these nanostructures exhibited high surface area and improved catalytic activity for methanol oxidation reaction.

  6. How the vestibular system interacts with somatosensory perception: a sham-controlled study with galvanic vestibular stimulation.

    Science.gov (United States)

    Ferrè, Elisa R; Day, Brian L; Bottini, Gabriella; Haggard, Patrick

    2013-08-29

    The vestibular system has widespread interactions with other sensory modalities. Here we investigate whether vestibular stimulation modulates somatosensory function, by assessing the ability to detect faint tactile stimuli to the fingertips of the left and right hand with or without galvanic vestibular stimulation (GVS). We found that left anodal and right cathodal GVS, significantly enhanced sensitivity to mild shocks on either hand, without affecting response bias. There was no such effect with either right anodal and left cathodal GVS or sham stimulation. Further, the enhancement of somatosensory sensitivity following GVS does not strongly depend on the duration of GVS, or the interval between GVS and tactile stimulation. Vestibular inputs reach the somatosensory cortex, increasing the sensitivity of perceptual circuitry. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Kinetics of chalcopyrite galvanic leaching using sulfate media at the low temperature in the GalvanoxTM process

    Directory of Open Access Journals (Sweden)

    Soghra Salehi

    2016-12-01

    Full Text Available In this research work, the dissolution of chalcopyrite was investigated under atmospheric pressure, with sulfate media at low temperatures, in 30°C to 50°C. In the galvanic interaction between chalcopyrite and pyrite, pyrite is used as a leaching catalyst. Effects of different parameters such as temperature, stirring speed, pyrite to chalcopyrite ratio, particle size, and solution potential were examined. Results showed that maximum copper recovery in low temperature was achieved after 24 hours, under the following condition: stirring speed of 800 rpm, pyrite to chalcopyrite ratio 4, solution potential 440 mV, temperature 50°C, and particle size of -38 microns. In addition, kinetic studies indicated that chalcopyrite dissolution with pyrite followed the shrinking core model, and the reaction was controlled by the surface reaction. Activation energy (Ea was calculated as 88 kJ/mol.

  8. [Document for assessing chemical and carcinogenic risk in the galvanic industry. Experience of the ASL 13 in Piemonte].

    Science.gov (United States)

    Castelli, A; Calò, B; Cucco, I; Lazzarotto, W

    2008-01-01

    To reduce the professional risks linked to exposure in the galvanic industries, in this Regional project, we gave particular attention to the analysis of the documents which evaluated both chemical and cancerogenous risk. Under Legislative Decree n. 626/1994 we examined the documents of 45 different companies. In many cases, we found a poor technical-scientific level. These documents were practically unusable and moreover were difficult to interpret for workers in this field. Motivations are probably to lead back to the complexity of the problem and to the insufficient sensibility of the responsible of the prevention in respect of risks with long-term effect, which are not immediately connected to the exposure.

  9. Study of the circular photo-galvanic effect in electrically gated (Bi,Sb)2Te3 thin films

    Science.gov (United States)

    Pan, Yu; Pillsbury, Timothy; Richardella, Anthony; Flanagan, Thomas; Samarth, Nitin

    Illumination with circularly polarized light is known to produce a helicity dependent photocurrent in topological insulators such as Bi2Se3 [Nature Nanotech. 7, 96 (2012)]. Symmetry considerations suggest that this ``circular photo-galvanic effect'' (CPGE) arises purely from the surface. However, whether or not the CPGE is directly related to optical excitations from the helical surface states is still under debate. To clarify the origin of the CPGE, we first compare the helicity dependent photocurrent in intrinsic (Bi,Sb)2Te3 to Cr doped (Bi,Sb)2Te3 thin films in which the Dirac surface states are perturbed by magnetic coupling. Secondly, we discuss the tunable CPGE in electrically gated (Bi,Sb)2Te3 thin films excited by optical excitations at different wavelengths. The dependence on the chemical potential and the photon energy of the excitation unveils the origin of the CPGE. Funded by ONR.

  10. Robert Hare's Theory of Galvanism: A Study of Heat and Electricity in Early Nineteenth-Century American Chemistry.

    Science.gov (United States)

    Fisher, Amy

    2018-04-09

    As a professor of chemistry at the University of Pennsylvania, Robert Hare actively shaped early American science. He participated in a large network of scholars, including Joseph Henry, François Arago, and Jacob Berzelius, and experimented with and wrote extensively about electricity and its associated chemical and thermal phenomena. In the early nineteenth century, prominent chemists such as Berzelius and Humphry Davy proclaimed that a revolution had occurred in chemistry through electrical research. Examining Robert Hare's contributions to this discourse, this paper analyzes how Hare's study of electricity and the caloric theory of heat led him to propose a new theory of galvanism. It also examines the reception of Hare's work in America and Great Britain, highlighting the contributions of early American chemists to the development of electrochemistry.

  11. Lap-joint testing of precoated steel materials

    Directory of Open Access Journals (Sweden)

    Chico, B.

    2003-12-01

    Full Text Available In industry, particularly in the building construction, lap-joint technology for precoated steel sheet materials has undergone rapid development. However, standars for lap-joint testing are lacking. This work analyses the behaviour of four precoated steel materials commonly used in the building industry: 55 % Al-Zn and hot dip galvanized, painted and unpainted. Two-year atmospheric exposure tests have been carried out in Madrid and Avilés (Spain, complemented by accelerated weathering tests in climatic cabinets. The latter have consisted of two salt fog/humidity/drying cycles: VDA cycle 621-415 and the "CENIM cycle", which has been designed to adequately simulate the behaviour of materials in this type of joints.

    En la industria en general y, particularmente, en la industria de la construcción, las tecnologías sobre uniones solapadas han experimentado un rápido desarrollo. Sin embargo, no son abundantes los ensayos para este tipo de uniones. Este trabajo analiza el comportamiento de cuatro materiales de acero pre-recubierto comúnmente usados en la industria de la construcción: 55 % Al-Zn y galvanizado por inmersión en caliente, con recubrimiento orgánico y sin él. Se han realizado ensayos de exposición natural durante dos años en las atmósferas de Madrid y Avilés (España, complementados con ensayos de envejecimiento acelerado en cámaras climáticas. En estos últimos se han ensayado dos ciclos de proyección niebla salina/humedad/secado: ciclo VDA 621-415 y un ciclo desarrollado en el CENIM diseñado.

  12. Process to Continuously Melt, Refine and Cast High Quality Steel

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    The purpose of this project is to conduct research and development targeted at designing a revolutionary steelmaking process. This process will deliver high quality steel from scrap to the casting mold in one continuous process and will be safer, more productive, and less capital intensive to build and operate than conventional steelmaking. The new process will produce higher quality steel faster than traditional batch processes while consuming less energy and other resources.

  13. Automatic surface inspection of pickled steel strips at Kawasaki Steel Chiba Works

    International Nuclear Information System (INIS)

    Okuno, M.; Torao, A.; Tomura, Y.; Tsujimoto, M.

    1999-01-01

    Conventional optical surface inspection systems for pickled steels have a problem in reliable inspection due to their varied surface nature. In order to solve this problem, new thresholding and classifying techniques were studied, and their performances were proved satisfactory in field tests. A new CCD-based inspection system using these techniques was installed in the No. 6 Pickling Line in Chiba Works, Kawasaki Steel Corporation. The camera arrangement of the system had been experimentally optimized. The system has been fully operational and has brought various benefits such as decrease in troubles caused by surface defects in the following processes. (author)

  14. Continuous steel production and apparatus

    Science.gov (United States)

    Peaslee, Kent D [Rolla, MO; Peter, Jorg J [McMinnville, OR; Robertson, David G. C. [Rolla, MO; Thomas, Brian G [Champaign, IL; Zhang, Lifeng [Trondheim, NO

    2009-11-17

    A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

  15. Thermochemical surface engineering of steels

    DEFF Research Database (Denmark)

    Thermochemical Surface Engineering of Steels provides a comprehensive scientific overview of the principles and different techniques involved in thermochemical surface engineering, including thermodynamics, kinetics principles, process technologies and techniques for enhanced performance of steels...

  16. Galvanic displacement synthesis of Al/Ni core–shell pigments and their low infrared emissivity application

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Le, E-mail: yuanle.cn@gmail.com [Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039 (China); National Engineering Research Center of Electromagnetic Radiation Control Materials, UESTC, Chengdu, 610054 (China); Hu, Juan [Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039 (China); Weng, Xiaolong [National Engineering Research Center of Electromagnetic Radiation Control Materials, UESTC, Chengdu, 610054 (China); Zhang, Qingyong [Center for Advanced Materials and Energy, Xihua University, Chengdu, 610039 (China); Deng, Longjiang [National Engineering Research Center of Electromagnetic Radiation Control Materials, UESTC, Chengdu, 610054 (China)

    2016-06-15

    We have successfully developed a magnetic Al/Ni core–shell pigment via a galvanic displacement reaction to obtain low infrared emissivity pigment with low lightness and visible light reflectance. Al/Ni core–shell particles were prepared via a simple one-step synthetic method where Ni was deposited onto the Al surface at the expense of Al atoms. The influence of pH and the amount of NH{sub 4}F complexing agent on phase structure, surface morphology, optical and magnetic properties were studied systematically. The neutral condition and high concentration of NH{sub 4}F forms smooth, flat, uniform and dense Ni shell on the surface of flake Al particles, which can significantly reduce the lightness and visible light reflectance but slightly increase the infrared emissivity. When the core–shell pigments are prepared in neutral pH solution at NH{sub 4}F = 11.2 g/L, the lightness (L{sup *}) and visual light reflectivity can be reduced by 12.6 and 0.46, respectively versus uncoated flake Al pigments, but the infrared emissivity is only increased by 0.02. The color changes from brilliant silver to gray black and the saturation magnetization value is 6.59 emu/g. Therefore, these Al/Ni magnetic composite pigments can be used as a novel low infrared emissivity pigment to improve the multispectral stealth performance of low-E coatings in the visual, IR and Radar wavebands. - Highlights: • Prepared magnetic Al/Ni core–shell pigment with low lightness and low emissivity. • Used one-pot galvanic displacement reaction to form smooth and dense Ni shell. • Show enhanced stealth performance in the visual, IR and Radar wavebands. • The lightness and visible light reflectance was decreased by 12.6 and 0.46. • But the infrared emissivity was only increases by 0.02.

  17. Fatigue damage of steel components

    DEFF Research Database (Denmark)

    Fæster, Søren; Zhang, Xiaodan; Huang, Xiaoxu

    2014-01-01

    Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials......Railway rails and the inner ring in roller bearings in wind turbines are both experiencing steel-to-steel contact in small areas with huge loads resulting in extremely high stresses in the base materials...

  18. Coated 4340 Steel

    Science.gov (United States)

    2013-08-26

    NAWCADPAX/TR-2013/252 4 MECHANICAL TEST Single edge notched, square-bar ( Charpy ) specimens, bare or coated, were tested under four-point bending at...Treated 4340 Steel Tested in Air NAWCADPAX/TR-2013/252 APPENDIX 100 150 200 250 300 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07 1.E+08 M ax . S tr es s ( ks i...Fatigue Life, N (cycle) Bare No. 1 ST No. 3 ST Figure 10: Stress-Life Fatigue Curves for Bare and Surface-Treated 4340 Steel Tested in 3.5% NaCl

  19. Joining uranium to steel

    International Nuclear Information System (INIS)

    Perkins, M.A.

    1976-05-01

    A method has been devised which will allow the joining of uranium to steel by fusion welding through the use of an intermediate material. Uranium-0.5 titanium was joined to AISI 304L stainless steel by using a vanadium insert. Also, a method is now available for selecting possible filler metals when two entirely dissimilar metals need to be joined. This method allows a quantitative ranking to be made of the possible filler metals and thus the most likely candidate can be selected

  20. A-3 steel work completed

    Science.gov (United States)

    2009-01-01

    Stennis Space Center engineers celebrated a key milestone in construction of the A-3 Test Stand on April 9 - completion of structural steel work. Workers with Lafayette (La.) Steel Erector Inc. placed the last structural steel beam atop the stand during a noon ceremony attended by more than 100 workers and guests.

  1. A Tale of Wootz Steel

    Indian Academy of Sciences (India)

    Damascus steels were not replicated in Europe until 1821. The pattern welded composite swords are the essence of the Samurai and Viking. 3. The Role of Wootz Steel in the Development of. Modern Metallurgy. For centuries iron and steel were thought as being two elements belonging to the ferrous family, just as copper, ...

  2. A Tale of Wootz Steel

    Indian Academy of Sciences (India)

    Mediterranean sources including one from the time of Alexander. (3rd c. BC), who was said to have been presented with 100 talents of Indian steel. Arabs took ingots of wootz steel to Damascus following which a thriving industry developed there for making weapons and armour of this steel, the renown of which has given.

  3. Advanced coking process control at Rautaruukki Steel

    Energy Technology Data Exchange (ETDEWEB)

    Ritamaki, O.; Luhtaniemi, H. [Rautaruukki Engineering (Finland)

    1999-12-01

    The paper presents the latest development of the Coking Process Management System (CPMS) at Raahe Steel. The latest third generation system is based on the previous system with the addition of fuzzy logic controllers. (The previous second generation system was based simultaneous feed forward and feedback control.) The system development has resulted in balanced coke oven battery heating, decreased variation in process regulation between shifts and increase of process information for operators. The economic results are very satisfactory. 7 figs.

  4. 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)....

  5. 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

  6. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 ... Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/006/01/0084-0088 ...

  7. Guns, Germs and Steel

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 1. Guns, Germs and Steel - A Short History of Everybody for the Last 13,000 years. Suri Venkatachalam. Book Review Volume 6 Issue 1 January 2001 pp 84-88. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Special steel production on common carbon steel production line

    Science.gov (United States)

    Pi, Huachun; Han, Jingtao; Hu, Haiping; Bian, Ruisheng; Kang, Jianjun; Xu, Manlin

    2004-06-01

    The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron & Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended.

  9. Special steel production on common carbon steel production line

    International Nuclear Information System (INIS)

    Pi Huachun; Han Jingtao; Hu Haiping; Bian Ruisheng; Kang Jianjun; Xu Manlin

    2004-01-01

    The equipment and technology of small bar tandem rolling line of Shijiazhuang Iron and Steel Co. in China has reached the 90's international advanced level in the 20th century, but products on the line are mostly of common carbon steel. Currently there are few steel plants in China to produce 45 steel bars for cold drawing, which is a kind of shortage product. Development of 45 steel for cold drawing has a wide market outlook in China. In this paper, continuous cooling transformation (CCT) curve of 45 steel for cold drawing used for rolling was set out first. According to the CCT curve, we determined some key temperature points such as Ac3 temperature and Ac1 temperature during the cooling procedure and discussed the precipitation microstructure at different cooling rate. Then by studying thermal treatment process of 45 steel bars for cold drawing, the influence of cooling time on microstructure was analyzed and the optimum cooling speed has been found. All results concluded from the above studies are the basis of regulating controlled cooling process of 45 steel bars for cold drawing. Finally, the feasible production process of 45 steel bars for cold drawing on common carbon steel production line combined with the field condition was recommended

  10. Newly developed electrical steel for high-frequency use

    Science.gov (United States)

    Komatsubara, M.; Sadahiro, K.; Kondo, O.; Takamiya, T.; Honda, A.

    2002-04-01

    For high-frequency appliances, a new magnetic material was developed, and its properties were investigated and compared with conventional electrical steel and 6.5% Si steel. The new material has extremely low iron loss at high frequencies over 5 kHz as well as 6.5% Si steel, which was obtained by increasing electric resistivity, or by reducing its eddy current loss. Generally, increasing resistivity makes steels brittle and deteriorates their workability. However, the developed material showed a good workability with the effect of Cr addition. This material has a good property of pulse response, and also showed an excellent performance for power electronics device using an active filter operated at 15 kHz.

  11. Assessing The Stregth And Weldability Of Historic Structural Steel

    Science.gov (United States)

    Dudkiewicz, Jacek; Gosowski, Bronisław; Organek, Piotr

    2015-09-01

    In practice, in the design stage of revitalization, renovation or reinforcement, there is often a need to determine the strength of steel as well as its weldability. The strength of steel can be determined in two ways: directly through destructive testing or indirectly - by the Brinell hardness test. In the case of weldability, this turns out to be much more difficult, because there are three groups of factors which determine this property, i.e.: local weldability, operative weldability, and overall weldability. This paper presents the results of the verification of the relationship between the hardness and strength of three grades of steel from the early twentieth century. The evaluation of the overall weldability of structural steels is discussed in an analytical approach preceding costly weldability tests. An assessment based on selected indicators of weldability can only lead to confusion.

  12. Assessing The Stregth And Weldability Of Historic Structural Steel

    Directory of Open Access Journals (Sweden)

    Dudkiewicz Jacek

    2015-09-01

    Full Text Available In practice, in the design stage of revitalization, renovation or reinforcement, there is often a need to determine the strength of steel as well as its weldability. The strength of steel can be determined in two ways: directly through destructive testing or indirectly - by the Brinell hardness test. In the case of weldability, this turns out to be much more difficult, because there are three groups of factors which determine this property, i.e.: local weldability, operative weldability, and overall weldability. This paper presents the results of the verification of the relationship between the hardness and strength of three grades of steel from the early twentieth century. The evaluation of the overall weldability of structural steels is discussed in an analytical approach preceding costly weldability tests. An assessment based on selected indicators of weldability can only lead to confusion.

  13. Designing high-temperature steels via surface science and thermodynamics

    Science.gov (United States)

    Gross, Cameron T.; Jiang, Zilin; Mathai, Allan; Chung, Yip-Wah

    2016-06-01

    Electricity in many countries such as the US and China is produced by burning fossil fuels in steam-turbine-driven power plants. The efficiency of these power plants can be improved by increasing the operating temperature of the steam generator. In this work, we adopted a combined surface science and computational thermodynamics approach to the design of high-temperature, corrosion-resistant steels for this application. The result is a low-carbon ferritic steel with nanosized transition metal monocarbide precipitates that are thermally stable, as verified by atom probe tomography. High-temperature Vickers hardness measurements demonstrated that these steels maintain their strength for extended periods at 700 °C. We hypothesize that the improved strength of these steels is derived from the semi-coherent interfaces of these thermally stable, nanosized precipitates exerting drag forces on impinging dislocations, thus maintaining strength at elevated temperatures.

  14. Corrosion in lithium-stainless steel thermal-convection systems

    International Nuclear Information System (INIS)

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

    1980-01-01

    The corrosion of types 304L and 316 austenitic stainless steel by flowing lithium was studied in thermal-convection loops operated at 500 to 650 0 C. Both weight and compositional changes were measured on specimens distributed throughout each loop and were combined with metallographic examinations to evaluate the corrosion processes. The corrosion rate and mass transfer characteristics did not significantly differ between the two austenitic stainless steels. Addition of 500 or 1700 wt ppM N to purified lithium did not increase the dissolution rate or change the attack mode of type 316 stainless steel. Adding 5 wt % Al to the lithium reduced the weight loss of this steel by a factor of 5 relative to a pure lithium-thermal-convection loop

  15. Clean cast steel technology. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Bates, C.E.; Griffin, J.A.

    1998-06-01

    This report documents the results obtained from the Clean Cast Steel Technology Program financially supported by the DOE Metal Casting Competitiveness Research Program and industry. The primary objective of this program is to develop technology for delivering steel free of oxide macroinclusions to mold cavities. The overall objective is to improve the quality of cast steel by developing and demonstrating the technology for substantially reducing surface and sub-surface oxide inclusions. Two approaches are discussed here. A total of 23 castings were produced by submerge pouring along with sixty conventionally poured castings. The submerged poured castings contained, on average, 96% fewer observable surface inclusions (11.9 vs 0.4) compared to the conventionally poured cast parts. The variation in the population of surface inclusions also decreased by 88% from 5.5 to 0.7. The machinability of the casting was also improved by submerged pouring. The submerge poured castings required fewer cutting tool changes and less operator intervention during machining. Subsequent to these trials, the foundry has decided to purchase more shrouds for continued experimentation on other problem castings where submerge pouring is possible. An examination of melting and pouring practices in four foundries has been carried out. Three of the four foundries showed significant improvement in casting quality by manipulating the melting practice. These melting practice variables can be grouped into two separate categories. The first category is the pouring and filling practice. The second category concerns the concentration of oxidizable elements contained in the steel. Silicon, manganese, and aluminum concentrations were important factors in all four foundries. Clean heats can consistently be produced through improved melting practice and reducing exposure of the steel to atmospheric oxygen during pouring and filling.

  16. Aging degradation of cast stainless steel

    International Nuclear Information System (INIS)

    Chopra, O.K.; Chung, H.M.

    1986-10-01

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich α' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by α' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 450 0 C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450 0 C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed

  17. Immobilization of heavy metals arising sludge galvanic, in glass ceramic material; Imobilizacao de metais pesados oriundos de lodo galvanico em material vitreo

    Energy Technology Data Exchange (ETDEWEB)

    Felisberto, R., E-mail: regina.felisberto@poa.ifrs.edu.br [Instituto Federal do Rio Grande do Sul (IFRS), Porto Alegre, RS (Brazil); Santos, M.C.; Basegio, T.; Bergmann, C.P. [Universidade Federal do Rio Grande do Sul (PPGEM/UFRGS), Porto Alegre, RS (Brazil)

    2016-07-01

    The use of galvanic sludge in the glass-ceramic formulation for immobilizing environmentally harmful materials is consolidated in more developed countries as raw material in the formulation of new materials. In this work, we have used galvanic sludge provided by a metallurgical company located in Vale dos Sinos, RS. The sludge was dried at 105°C and mixed with soda-lime glass in proportions of 1, 5, 10 and 20%, relative to the glass mass. Its composition was determined by FRX, and evaluated for leaching (NBR 10005) and solubilization (NBR 10006). The specimens (CPs) were burned at temperatures 750, 800 and 850°C, also submitted to the tests. The sludge, Class I - dangerous, presented Se content greater than provisions of NBR 10004. It was possible to immobilize the heavy metals at a temperature of 850°C for specimens of the F1 formulation, having been thus classified as Class II B Inert Residue. (author)

  18. Steel Creek primary producers: Periphyton and seston, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    International Nuclear Information System (INIS)

    Bowers, J.A.; Toole, M.A.; van Duyn, Y.

    1992-02-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor and to protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to assess various components of the system and identify and changes due to the operation of L-Reactor or discharge from L Lake. An intensive ecological assessment program prior to the construction of the lake provided baseline data with which to compare data accumulated after the lake was filled and began discharging into the creek. The Department of Energy must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems. This report summarizes the results of six years' data from Steel Creek under the L-Lake/Steel Creek Monitoring Program. L Lake is discussed separately from Steel Creek in Volumes NAI-SR-138 through NAI-SR-143

  19. Steel Creek primary producers: Periphyton and seston, L-Lake/Steel Creek Biological Monitoring Program, January 1986--December 1991

    Energy Technology Data Exchange (ETDEWEB)

    Bowers, J.A. [Westinghouse Savannah River Co., Aiken, SC (United States); Toole, M.A.; van Duyn, Y. [Normandeau Associates Inc., New Ellenton, SC (United States)

    1992-02-01

    The Savannah River Site (SRS) encompasses 300 sq mi of the Atlantic Coastal Plain in west-central South Carolina. Five major tributaries of the Savannah River -- Upper Three Runs Creek, Four Mile Creek, Pen Branch, Steel Creek, and Lower Three Runs Creek -- drain the site. In 1985, L Lake, a 400-hectare cooling reservoir, was built on the upper reaches of Steel Creek to receive effluent from the restart of L-Reactor and to protect the lower reaches from thermal impacts. The Steel Creek Biological Monitoring Program was designed to assess various components of the system and identify and changes due to the operation of L-Reactor or discharge from L Lake. An intensive ecological assessment program prior to the construction of the lake provided baseline data with which to compare data accumulated after the lake was filled and began discharging into the creek. The Department of Energy must demonstrate that the operation of L-Reactor will not significantly alter the established aquatic ecosystems. This report summarizes the results of six years` data from Steel Creek under the L-Lake/Steel Creek Monitoring Program. L Lake is discussed separately from Steel Creek in Volumes NAI-SR-138 through NAI-SR-143.

  20. Corrosion of Steel in Concrete – Potential Monitoring and Electrochemical Impedance Spectroscopy during Corrosion Initiation and Propagation

    DEFF Research Database (Denmark)

    Küter, Andre; Mason, Thomas O.; Geiker, Mette Rica

    2005-01-01

    included grit blasting, electrochemical and hydrochloric acid cleaning (HCl) as well as weathering. The results indicate that the investigated treatments of the carbon steel surface have no major effect on the initiation period, which was approximately 20 days under the actual conditions. The galvanized......A reinforced mortar specimen that allows potential measurements and electrochemical impedance spectroscopy (EIS) immediately after preparation was designed and tested. The specimen consists of a mortar cylinder with a central rebar and a concentric arrangement of embedded Ru/Ir activated titanium...... wires. The wires can act as both reference and counter electrode during EIS and, thus, no external electrode is required. The defined geometry solves reproducibility problems involved with application of an external reference electrode for EIS. Changes of the electromotive force (EMF) between rebar...