Center for Corrosion Science and Engineering

Washington, DC, United States

Center for Corrosion Science and Engineering

Washington, DC, United States
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Horton D.J.,Center for Corrosion Science and Engineering | Strom M.J.,Center for Corrosion Science and Engineering | Tagert J.P.,Center for Corrosion Science and Engineering | Cassidy P.,Washington Technology
NACE - International Corrosion Conference Series | Year: 2017

Thermal spray non-skid (TSN) coatings are multifunctional coatings typically used on Navy flight decks to withstand extreme temperatures, provide a non-skid surface profile and serve as a barrier coating to the mild steel substrate. When the corrosion barrier coating is breached, TSN must provide sacrificial corrosion protection to the substrate. TSN coatings can have a high porosity and can be susceptible to micro-cracking under certain loading conditions (i.e., flight deck buckling). As a result, there is a motivation to apply sealants to increase the barrier protection capability and extend the service life of TSN. The desire to have both an effective barrier coating to protect the thermal spray while maintaining sacrificial protection of the substrate requires an intricate synergy between these methods of protection. An effective barrier coating aims to minimize exposed surface area and, when damaged, to prevent damaged areas from spreading over time. Conversely, a sacrificial layer requires a large exposed surface area proximate to the damaged area in order to maintain long term protection of the substrate. The objective of this work is to investigate this synergy in order to elucidate the factors that have the greatest influence over the corrosion protection properties and failure modes of TSN. Corrosion protection properties of TSN were determined as a function of cathodic protection efficacy and how sealants might reduce effective anodic surface area on both near and long term time scales. To evaluate these factors TSN coating were initially evaluated to determine the surface area of asapplied TSN coatings. The coatings were subjected to controlled anodic discharge cycles to determine characteristic changes in behavior. Coating degradation was characterized using a combination of impedance spectroscopy and electron microscopy to quantify protection strength and loss of available active surface area as a function of different coatings and simulated exposure conditions (i.e., salt spray, extreme temperature, etc.). © 2017 by NACE International.

Horton D.J.,Center for Corrosion Science and Engineering | Anderson R.M.,U.S. Navy | Sanders C.E.,Center for Corrosion Science and Engineering | Davis R.S.,U.S. Navy | Lemieux E.J.,Center for Corrosion Science and Engineering
NACE - International Corrosion Conference Series | Year: 2017

Often the most severe maritime environmental degradation for ships occurs just above the waterline within the splash zone where periodic wet-dry cycles accelerate corrosion. Similarly, increased corrosion also occurs at coastal areas where nearby wave action generates more sea-spray aerosols. These areas are subjected to typical degradation through atmospheric deposition and stressors such as UV light but also have an increased time of wetness (ToW) and higher chloride deposition rate compared to atmospheric exposure alone. It has been seen previously that elevated ToW and chloride loading are correlated to higher corrosion rates of various materials. The objective of this work was to compare the effect on corrosion of different field exposure conditions: atmospheric exposure in a medium chloride environment, atmospheric exposure with periodic seawater spray, cyclic alternate immersion, and a typical accelerated atmospheric testing protocol (GM 9540). Test materials included copper alloy, silver, and carbon steel. Oxide analysis was performed using coulometric reduction and used in conjunction with microscopy, glow discharge optical emission spectrometery and x-ray diffraction to determine the type of surface films present, the presence of specific species and film thickness for the exposed materials. In addition to a comparison of different exposure methods, a time-resolved comparison between atmospheric exposure and atmospheric exposure with the addition of seawater spray was made. © 2017 by NACE International.

Groenenboom M.C.,University of Pittsburgh | Anderson R.M.,National Research Council Italy | Horton D.J.,Center for Corrosion Science and Engineering | Basdogan Y.,University of Pittsburgh | And 3 more authors.
Journal of Physical Chemistry C | Year: 2017

The oxygen reduction reaction (ORR) is a major factor that drives galvanic corrosion. To better understand how to tune materials to better inhibit catalytic ORR, we have identified an in silico procedure for predicting elemental dopants that would cause common, natively formed titanium oxides to better suppress this reaction. In this work, we created an amorphous TiO2 surface model that is in good agreement with experimental radial distribution function data and contains reaction sites capable of replicating experimental ORR overpotentials. Dopant performance trends predicted with our quantum chemistry model mirrored experimental results, and our top three predicted dopants (Mn, Al, and V, each present at doping concentrations of 1%) were experimentally verified to lower ORR currents under alkaline conditions by up to 77% vs the undoped material. These results show the robustness of calculated thermodynamic descriptors for identifying poor, TiO2-based ORR catalysts. This also opens the possibility of using quantum chemistry to guide the design of coating materials that would better resist the ORR and presumably galvanic corrosion. © 2017 American Chemical Society.

News Article | April 11, 2016

A five-member team of researchers from the U.S. Naval Research Laboratory (NRL) Center for Corrosion Science and Engineering received the Office of Naval Research (ONR) Prize for Affordability, Aug. 26, at an award ceremony held at ONR in Alexandria, Va. The award honors materials research engineers James Martin, head of the Marine Coatings Science Section, Jimmy Tagert, and John Wegand; research chemist, Dr. Erick Iezzi; and physical scientist technician, Paul Slebodnick for significant contributions to an overall reduction in the total ownership costs associated with corrosion control of Navy ships and submarines and achievements in the development and transition of nonskid and topside coatings to the fleet. The team formulated, synthesized, and commercialized topside and nonskid coatings having longer life, high durability, improved weathering resistance and color stability, to replace both legacy nonskid decking and topside coatings. The Navy installs nearly 3.7 million square feet of non-skid coatings per year that typically cost over $56 million annually. Conventional epoxy based nonskids have a 12 to 36 month lifecycle, while topside coatings have a 24 to 36 month life. The new NRL-developed polysiloxane system doubles or triples the life expectancy of this system. For topside coatings, not only are lifetimes increased, but also installation costs are reduced by up to 28 percent through the reduced number of coats over conventional systems. As a result, polysiloxane coatings systems have been qualified and approved for use by Naval Sea Systems Command (NAVSEA) and have been mandated for all topside depot level maintenance availabilities. The NRL polysiloxane nonskid decking system is planned for qualification in 2015. At present, the nonskid coatings system has exceeded the one-year flight deck requirement on-board the USS Theodore Roosevelt (CVN 71), has outperformed all previous nonskids on-board the USS Michigan (SSGN 727), and is still performing well on-board the USS Bulkeley (DDG 84). On Navy submarines, this system is the only system ever to pass the submarine nonskid requirements. The Center for Corrosion Science and Engineering (CCSE) conducts broad scientific and engineering programs to understand and reduce the effects of the marine environment on naval systems. Within the CCSE, the Marine Coatings Science Section conducts basic and applied research to synthesize and produce advanced, multi-functional marine coatings technology for all naval environments including immersion, alternate immersion and atmospheric exposures typical of Navy and Marine Corps platforms. About the U.S. Naval Research Laboratory The U.S. Naval Research Laboratory provides the advanced scientific capabilities required to bolster our country's position of global naval leadership. The Laboratory, with a total complement of approximately 2,500 personnel, is located in southwest Washington, D.C., with other major sites at the Stennis Space Center, Miss., and Monterey, Calif. NRL has served the Navy and the nation for over 90 years and continues to advance research further than you can imagine. For more information, visit the NRL website or join the conversation on Twitter, Facebook, and YouTube.

Policastro S.A.,Center for Corrosion Science and Engineering | Hangarter C.M.,Excet Inc. | Horton D.J.,Center for Corrosion Science and Engineering | Wollmershauser J.A.,U.S. Navy | Roeper D.F.,Excet Inc.
Journal of the Electrochemical Society | Year: 2016

The electrochemical behavior of oxides of three Ti-based binary alloys, Ti99Co1, Ti99Sn1, and Ti99Cr1, are investigated using electrochemical impedance spectroscopy, Mott-Schottky analysis and cyclic voltammetry. It is found that native amorphous TiO2 can be doped in order to change the oxide's electronic properties and thereby reduce oxygen reduction rates in an alkaline solution, with the greatest reduction seen for the Ti99Sn1 alloy. © 2016 The Electrochemical Society.

Hangarter C.M.,Excet Inc. | Policastro S.A.,Center for Corrosion Science and Engineering | Martin F.J.,Center for Corrosion Science and Engineering
ECS Transactions | Year: 2015

A mechanistic understanding of how electrolyte composition and metal oxide can influence corrosion kinetics in the electrolytes formed from atmospheric processes is investigated. Galvanic couples between aluminum alloys and titanium or stainless steel fasteners exposed to electrolytes formed from atmospheric processes lead to very different corrosion rates. The differences in cathodic current capacity for materials exposed to the same electrolyte at the same aeration level reinforces the fact that oxide microstructure plays a role in catalyzing reduction reactions, though the kinetics of the reaction rates may not be predicted from a simple galvanic series. Also of interest are the changes in reaction rates from acidification of the electrolyte. This suggests that the electrolyte is changing the oxide microstructure or that new reduction reactions are supported and that material loss rates can be orders of magnitude higher for acidified atmospheric electrolytes. © The Electrochemical Society.

Heuer A.H.,Case Western Reserve University | Kahn H.,Case Western Reserve University | O'Donnell L.J.,Case Western Reserve University | Ernst F.,Case Western Reserve University | And 4 more authors.
Electrochemical and Solid-State Letters | Year: 2010

Interstitial hardening of the martensitic stainless steel PH13-8 Mo has been achieved by low temperature gas-phase carburization. After treatment, hardness is increased to a depth of ≈50 μm, with a surface hardness that is twice the core hardness and a corresponding improvement in pin-on-disk wear resistance. Pitting potential is increased by ≈0.5 V in 0.6 M NaCl. Elemental analysis and X-ray diffraction suggest the formation of a thin (≈2 μm) carbidic surface layer that is both wear and corrosion resistant. © 2010 The Electrochemical Society.

Kahn H.,Case Western Reserve University | Heuer A.H.,Case Western Reserve University | Michal G.M.,Case Western Reserve University | Ernst F.,Case Western Reserve University | And 5 more authors.
Surface Engineering | Year: 2012

The mechanical properties and corrosion resistance of duplex (ferrite-austenite) grade 2205 stainless steel have been substantially improved by interstitial hardening using low temperature carburisation. The austenite phase of the duplex stainless steel responds to low temperature carburisation in a similar manner as single phase austenitic stainless steels, forming 'expanded' austenite (also called S phase). The surface layer that forms on the ferritic portion of 2205 steel consists of a paraequilibrium carbide, a carbide with the same metal composition as the underlying ferrite. This two-phase case has about three times the Vickers hardness of non-treated material, an improved ultimate tensile strength and increased fatigue resistance, and much improved crevice corrosion resistance. © 2012 Institute of Materials, Minerals and Mining.

Policastro S.A.,U.S. Naval Academy | Auyeung R.C.Y.,U.S. Navy | Martin F.J.,Center for Corrosion Science and Engineering | Rayne R.J.,U.S. Navy | And 4 more authors.
Journal of the Electrochemical Society | Year: 2012

A novel experimental technique for making electrochemical measurements on individual phase or isolated regions of a metal or alloy is reported. The technique, called Selective Masking by Photolithography (SMP), uses a hardened photoresist coating to mask the excluded portions of the sample and 355 nm laser pulses are employed to expose individual grains or regions of interest. The size of the exposed area can range from tens of microns to millimeters. Localized electrochemical DC and AC measurements and critical pitting temperature determinations for the two phases in a duplex stainless steel were used to show the utility and viability of SMP. © 2011 The Electrochemical Society.

Holtz R.L.,U.S. Navy | Pao P.S.,U.S. Navy | Bayles R.A.,Center for Corrosion Science and Engineering | Longazel T.M.,Center for Corrosion Science and Engineering | Goswami R.,SAIC
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2012

The fatigue crack growth behavior of aluminum alloy 5083-H131 has been systematically studied as a function of degree of sensitization for aging at 448 K (175C). Fatigue crack growth rates were measured at load ratios of 0.1 and 0.85, in vacuum, air, and a corrosive aqueous environment containing 1 pct NaCl with dilute inhibitor. Sensitization does not affect the fatigue crack growth behavior of Al 5083-H131 significantly in vacuum or air, at low- or high-load ratio. For high-load ratio, in the 1 pct NaCl+inhibitor solution, the threshold drops by nearly 50 pct during the first 200 hours of aging, then it degrades more slowly for longer aging times up to 2000 hours. The change in aging behavior at approximately 200 hours seems to be correlated with the transition from partial coverage of the grain boundaries by b Al3Mg2 phase, to continuous full b coverage. ASTMG-67mass loss levels below approximately 30 mg/cm2 do not exhibit degraded corrosion-fatigue properties for R = 0.85, but degradation of the threshold is rapid for higher mass loss levels. © The Minerals, Metals & Materials Society and ASM International 2011.

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