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At least 1,711 records · Page 95

Corrosion resistant neutron absorbing coatings

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

36 MATERIALS SCIENCE↗

Coupon Surveillance For Corrosion Monitoring In Nuclear Fuel Basin

Aluminum and stainless steel coupons were put into a nuclear fuel basin to monitor the effect of water chemistry on the corrosion of fuel cladding. These coupons have been monitored for over ten years. The corrosion and pitting data is being used to model the kinetics and estimate the damage that is occurring to the fuel cladding.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Corrosion Control Measures For Liquid Radioactive Waste Storage Tanks At The Savannah River Site

The Savannah River Site has stored radioactive wastes in large, underground, carbon steel tanks for approximately 60 years. An assessment of potential degradation mechanisms determined that the tanks may be vulnerable to nitrate- induced pitting corrosion and stress corrosion cracking. Controls on the solution chemistry and temperature of the wastes are in place to mitigate these mechanisms. These controls are based upon a series of experiments performed using simulated solutions on materials used for construction of the tanks. The technical bases and evolution of these controls is presented in this paper.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Corrosion resistant neutron absorbing coatings

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

36 MATERIALS SCIENCE↗

Influence of Temperature on CaO-MgO-Al2O3-SiO2 (CMAS) Corrosion on Thermal Barrier Coatings

Higher operating temperature improves the energy efficiency in gas turbine engines and thermal barrier coatings are applied to protect the blades from high temperature and dust corrosion. Dust composed by CaO-MgO-Al2O3-SiO2 (CMAS) can melt and react with pyrochlore zirconates thermal barrier materials and degrade the performance or cause failure of the coatings. This paper discusses the relationship of the reaction product and corrosion temperature.

20 FOSSIL-FUELED POWER PLANTS↗

Corrosion Tests with Developmental Iron Phosphate Glass Waste Forms

Corrosion tests are in progress to assess the dissolution behavior of developmental iron phosphate waste forms for salt waste from electrochemical separation operations. Specimens cut from materials made at PNNL to represent a range of waste salt loadings in prototype composition DPF-5 and a range of iron oxide loadings in prototype composition DPF-3 were subjected to modified ASTM C1308 tests to assess the compositional effects on the relative durabilities and retention of immobilized salt cations. The materials were composed of different amounts of glass and crystalline phases. The test results show both the intrinsic durability of the material and the salt cation retention decrease as the total amount of salt cations added to the material is increased. The results of ASTM C1220 and ASTM C1285 tests conducted with materials DPF5-280 and DPF5-336, which contained about 28% and 34% salt cations (on a mass oxide basis) and bounded the durabilities of the other materials, show that solution feedback does not attenuate the dissolution rate. This suggests the degradation of iron phosphate waste forms can be modelled by using a constant rate that probably depends on the composition and volume fraction of the glass phase. A reference composition should be formulated and used in tests to determine those dependencies. The ASTM C1220 and ASTM C1285 tests with DPF5-280 and DPF5-336 remain in progress to corrode the specimens enough to distinguish the relative extents of glass and crystalline phase corrosion by microscopic examinations. Those results are expected to provide insights regarding the relative dissolution rates of crystalline and glass phases and impact on durability to inform the formulation of the reference composition.

Ebert, W. L.↗

Non-contact monitoring of biofilms and corrosion on submerged surfaces with electrochemical impedance spectroscopy

Systems and methods for monitoring microorganisms on a surface are provided. In particular, a flat, patterned sensing electrode can be positioned proximate a surface in non-contact relationship with the surface. The sensing electrode can include a working electrode and a counter electrode. The surface and the sensing electrode can be submerged in an aqueous medium. An alternating current signal can be applied at the working electrode. The signal can propagate through the aqueous medium and can be measured at the counter electrode. The presence of microorganisms on the surface can cause changes in the signal as the signal propagates through the aqueous medium. Such changes in the signal can be used to determine impedance parameters, which can correspond to microbial characteristics associated with the surface. For instance, the microbial characteristics can be associated with a biofilm, corrosion and/or bio-corrosion on the surface.

Turick, Charles E.↗

CORROSION PERFORMANCE OF MIL-PRF-23377 PRIMER COATED ON LASER-INTERFERENCE STRUCTURED ALUMINUM ALLOY 2024

Laser-Interference Structuring (LIS) is a technique that was proposed to treat aluminum surfaces for improving primer adhesion. LIS may not require a series of chemical treatments, such as those used in chemical conversion coating (CCC) and sulfuric acid anodizing (SAA), which make the pre-treatment of Al panels simpler and quicker for primer painting. Previous test results indicated that LIS surface preparation enhances coating adhesion on Al 2024. To assess the effect of LIS on corrosion resistance of coatings, Al 2024 panels prepared by LIS, CCC and SAA were coated with MIL-PRF-23377 primers and exposed to salt spray environment according to ASTM B117. The exposure is currently in progress and the corrosion attack on the coated panels will be evaluated by the degree of blister formation and rust creepage according to ASTM standards.

Jun, Jiheon↗

Effect of dissolved oxygen level on stress corrosion cracking susceptibility of structural steels

Stress corrosion cracking (SCC) is a potential risk in structural steels used for heat exchanger and circulation loop in LWR. Generally, SCC susceptibility of structural steels increases with increasing the level of dissolved oxygen (DO) in circulating water, but DO tolerance below which no SCC risk is present could differ by the type of steel. To investigate the DO effect on SCC susceptibility, T23, T24 and T91 steels under static load were exposed to stagnant and circulating water at 200°C with varying DO levels. The results indicated that among the tested steels, the SCC susceptibility was highest in T91 but lowest in T23 which did not exhibit crack initiation with 100 ppb DO. T24 showed no cracking with 50 ppb DO but cracked with 100 ppb DO, implying intermediate SCC susceptibility in between T23 and T91. Based on the cracking results and hardness data, SCC susceptibility in the tested steels is considered driven by corrosion which was initiated/affected by DO in the water.

Jun, Jiheon↗

CORROSION RESISTANCE OF LASER-INTERFERENCE STRUCTURED ALUMINUM ALLOY 2024 COATED WITH MIL-PRF-85582 PRIMER

The use of aluminum alloys in aerospace industry requires more effective and reliable joining techniques. The lubricant contaminants from prior rolling operations affect surface energies and the quality of coating adhe-sion and adhesive bonded joints. In this study, a new laser-based technique is investigated as a surface treatment for coating applications. The laser interference power profile was created by splitting the beam and guiding both beams towards the specimen and overlapping them on the specimen surface, creating a line-interference pattern on the specimen surface. The laser-interference structuring (LIS) was used without any chemical treatments, such as those in chemical conversion coating (CCC) and sulfuric acid anodizing (SAA), which is a much simpler process than those chemical-based. To assess the effect of LIS on corrosion re-sistance of coating, Al 2024 panels prepared by LIS, CCC and SAA were coated with MIL-PRF-85582, Type I, Class N primer and exposed to salt spray environment according to ASTM B117. The exposure is currently in progress and the corrosion attack on the coated panels will be evaluated by the degree of blister formation and rust creepage.

Sabau, Adrian↗

Optical monitoring to detect corrosion of power grid components

A corrosion monitoring system includes one or more objects coupled to respective portions of a transformer tank. The one or more objects are configured to corrode before the respective portions of the transformer tank. At least one optical sensor is coupled to each of the objects. The at least one optical sensor has an optical output that changes in response to strain of the object. An analyzer is coupled to the at least one optical sensor. The analyzer is configured to perform one or more of detecting and predicting corrosion of the transformer tank based on the output of the at least one optical sensor.

Teepe, Mark R.↗

Corrosion resistive materials, systems, and methods of forming and using the materials and systems

A method to reduce corrosion rates of materials at high temperatures may include heating a mixture and applying the heated mixture to a material to be rendered thermodynamically noble. The mixture may include carbon monoxide and carbon dioxide and the material rendered thermodynamically noble may include copper or other material having similar physical properties. The copper or other similar material may be applied to a structural material and provide a surface interfacing with the mixture of carbon monoxide and carbon dioxide to prevent corrosion of the structural material. In some cases, the structural material may form a heat exchanger defining passageways for a working fluid of a power system and/or may form other passageways of the power system. The copper may be applied to the passageways as a protective coating and then made thermodynamically noble at high temperatures after interactions with the mixture of carbon monoxide and carbon dioxide.

Anderson, Mark↗

High temperature corrosion sensor

A high temperature corrosion sensor is provided having (i) a housing having an external wall and an internal wall, the internal wall of the housing forming a chamber of the housing, (ii) a stainless steel tube inserted into the chamber, (iii) a ceramic tube wherein at least a portion of the ceramic tube is inserted into the stainless steel tube, (iv) an airflow tube that extends through the chamber, and (v) a sensor probe having a first working electrode, a second working electrode, a reference electrode, a positive electrical resistance, a negative electrical resistance, and a thermocouple, wherein at least a portion of each are encapsulated into a ceramic casting that is located at one end of the housing. Methods of measuring corrosion within a power plant environment are provided.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

High-performance corrosion-resistant high-entropy alloys

This disclosure provides alloy compositions comprising the main constituent elements iron, nickel, cobalt, molybdenum, and chromium. In one embodiment, the alloy comprises 10.0 to 30.0 wt % iron; 30.0 to 60.0 wt % nickel; 10.0 to 25.0 wt % cobalt; 1.0 to 15.0 wt % molybdenum; 15.0 to 25.0 wt % chromium by weight; where the sum of iron and nickel is at least 50 wt %; and, where the balance comprises minor elements, the total amount of minor elements being about 5% or less by weight. The alloy compositions have use as coatings to protect metals and alloys from corrosion in extreme environments where corrosion is a major concern such as with exposure to sea water or sea water with CO 2 .

Hawk, Jeffrey A.↗

Optical monitoring to detect corrosion of power grid components

A corrosion monitoring system includes one or more objects coupled to respective portions of a transformer tank. The one or more objects are configured to corrode before the respective portions of the transformer tank. At least one optical sensor is coupled to each of the objects. The at least one optical sensor has an optical output that changes in response to strain of the object. An analyzer is coupled to the at least one optical sensor. The analyzer is configured to perform one or more of detecting and predicting corrosion of the transformer tank based on the output of the at least one optical sensor.

Teepe, Mark↗

Distributed fiber-optic sensor network for sensing the corrosion onset and quantification

Materials, methods of making, and methods of sensing liquid droplets with high spatial resolution as a signature of the on-set of corrosion using a hierarchical sensor network A hierarchical sensor network for sensing liquid droplets with high spatial resolution as a signature of the on-set of corrosion, including an interrogation system; and an intermediate sensor array layer in communication with the interrogation system. The network includes an interrogation system and an intermediate sensor array layer in communication with the interrogation system.

Ohodnicki, Paul R.↗

Multi-Parameter Optical Fiber Sensing of Humidity, CH4, CO2, and Corrosion

In this work, the previously demonstrated capability of the optical fiber sensor (OFS) for successful monitoring of humidity has been extended to monitor the humidity, CH4, and CO2 with different gas composition based on the strain produced along the single mode fiber (SMF) sensor. This is enabled by absorption of H2O/gases on to the commercially available polyacrylate coated jacketed portion of the fiber resulting a change in strain. Under equilibrium, a differential microstrain was observed along the jacketed portion of the SMF with N2, CH4, and CO2 at different humidity conditions, while the unjacketed portion of the fiber was used only for sensing pressure/temperature induced strain. In case of N2 at 800 psig pressure, the observed microstrain was ~80, ~65, ~50 and ~35 µε at 100, 75.0, 46.8, and 23.4 RH% respectively. Comparatively, a microstrain of ~95 µε was observed with 100% RH CH4 which demonstrates that SMF produces a measurable CH4 response alongside water. Similarly, the observed microstrain with CO2 was ~105, ~90, ~85, ~ 80, and ~70 µε at 100, 75.0, 46.8, 23.4, and 0 RH% respectively. Linear regression and principal component analysis of these dataset provided deconvolution of the impact of strain from H2O, CH4, and CO2 enabling good cross sensitivity. Additionally, modified OFS comprising of Fe coated fiber section was employed to monitor corrosion based on the increase in backscattered intensity amplitude of the light being passed once corrosion occurs.

Mainali, Badri↗

On the Corrosion Response of Novel Heat Exchangers Manufactured by Casting of Al-Ce-Mg Alloy

Developing low-cost and durable heat exchangers is critical for next-generation heating, ventilation, air conditioning, and refrigeration systems. The emerging requirement to minimize the total refrigerant charge inventory while ensuring a uniform distribution of refrigerant has led to the deployment of advanced manufacturing strategies. At the same time, corrosion is a longstanding issue for metal components, especially those used in heat exchanger (HX) applications. In this study, Al-Ce-Mg alloy-based HXs have been investigated. The corrosion resistance of HXs prototype manufactured by the casting process has been examined and the potential of a new manufacturing approach has been explored to meet the requirements of emerging needs.

Brechtl, Jamieson↗