scholarly journals The Inclusion of Acidic and Stormwater Flows in Concrete Sewer Corrosion Mitigation Studies

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 261
Author(s):  
Georgios Fytianos ◽  
Anastasios Tsikrikis ◽  
Costas A. Anagnostopoulos ◽  
Efthimios Papastergiadis ◽  
Petros Samaras
Keyword(s):  
Axial Strain ◽  
Protective Layer ◽  
Corrosion Mechanism ◽  
Acid Attack ◽  
Sewer Pipes ◽  
Chemical Corrosion ◽  
Protective Layers ◽  
Oxidation Of Hydrogen ◽  
Acidic Waters ◽  
Positive Effect

Concrete sewer pipes can be deteriorated by sulfuric acid (H2SO4), which is created by the oxidation of hydrogen sulfide in the presence of certain bacteria inside the sewers. This process is called biocorrosion. In this paper, H2SO4 (i.e., chemical, non-biogenic) was used to study acid attack on concrete samples. The authors conducted experiments under different acid flows and concentrations, to account for the conditions prevailing in sewage networks exposed to flowing acidic waters. The effect of intermittent stormwater on the removal of protective layers was studied in addition to constant flow runs. Specimens’ erosion depth was measured with a Vernier micrometer. In addition, unconfined compression at an axial strain rate of 0.0016 mm/mm/min was used for the estimation of unconfined compressive strength and elastic modulus. Moreover, the formation of gypsum as a protective layer and its role in biocorrosion was discussed. From this study, it was concluded that although the utilization of constant flowrates of acidic waters represents an important indication of corrosion mechanism, intermittent sewage and water flows should be taken into account, corresponding to real conditions in sewage networks, and resulting into accelerated concrete corrosion. Stormwater in combined sewers could remove the protective gypsum layer, thus accelerating chemical corrosion; however, in the presence of biogenic H2SO4, the removal of gypsum by excess flows due to stormwater could have a positive effect on corrosion mitigation. Finally, for combined sewers, selected coatings should withstand the effect of stormwater and high-velocity water flow tests should be included in future studies.

scholarly journals The Role of Sacrificial and/or Protective Layers to Improve the Sintering of Electroactive Ceramics: Application to Piezoelectric PZT-Printed Thick Films for MEMS

Ceramics ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 453-475
Author(s):  
Hélène Debéda ◽  
Maria-Isabel Rua-Taborda ◽  
Onuma Santawitee ◽  
Simon Grall ◽  
Mario Maglione ◽  
...  
Keyword(s):  
Thick Film ◽  
Sacrificial Layer ◽  
Low Cost ◽  
Thick Films ◽  
Protective Layer ◽  
Protective Layers ◽  
Plasma Sintering ◽  
Wide Range ◽  
Spark Plasma ◽  
Pros And Cons

Piezoelectric thick films are of real interest for devices such as ceramic Micro-ElectroMechanical Systems (MEMS) because they bridge the gap between thin films and bulk ceramics. The basic design of MEMS includes electrodes, a functional material, and a substrate, and efforts are currently focused on simplified processes. In this respect, screen-printing combined with a sacrificial layer approach is attractive due to its low cost and the wide range of targeted materials. Both the role and the nature of the sacrificial layer, usually a carbon or mineral type, depend on the process and the final device. First, a sacrificial layer method dedicated to screen-printed thick-film ceramic and LTCC MEMS is presented. Second, the recent processing of piezoelectric thick-film ceramic MEMS using spark plasma sintering combined with a protective layer approach is introduced. Whatever the approach, the focus is on the interdependent effects of the microstructure, chemistry, and strain/stress, which need to be controlled to ensure reliable and performant properties of the multilayer electroceramics. Here the goal is to highlight the benefits and the large perspectives of using sacrificial/protective layers, with an emphasis on the pros and cons of such a strategy when targeting a complex piezoelectric MEMS design.

Study on the FRP Tendons in Acid Erosion Test of the Durability

2013 ◽  
Vol 706-708 ◽  
pp. 571-574
Author(s):  
Yun Feng Zhang ◽  
Fei Fei Han ◽  
De Wang Zhao ◽  
Shuai Shao
Keyword(s):  
Resin Matrix ◽  
Corrosion Mechanism ◽  
Reinforcement Corrosion ◽  
Fiber Reinforced ◽  
Thermoplastic Resin ◽  
Durability Test ◽  
Chemical Corrosion ◽  
Corrosive Effect ◽  
Resin Matrix Composite ◽  
Frp Bars

Abstract：In this paper,HCI solution in the chemical corrosion tests carried out in room temperature,measured mass loss of CFRP tendons. After extraction and analysis, preliminary search the FRP reinforcement corrosion mechanism under acid erosion. The tensile test is done at 60d and 120d,respectively. Determination of the tensile strength of CFRP tendons. The experimental analysis of the data collected, identify the law of CFRP reinforcement corrosion. Fiber reinforced composite material (Fiber Reinforced Polymer, of FRP ) is a continuous non-metallic fibers and fabric reinforced thermosetting or thermoplastic resin matrix composite made of a new material . Fibers and resin matrix composed of FRP bars under normal circumstances is not easy to rust, but in recent years, the study found that acid salt , moisture , UV , temperature and other environmental conditions on the long-term performance of FRP bars have a certain impact[3-5]. By CFRP tendons under acidic corrosion durability test study reveals CFRP tendons under the corrosive effect of the variation of the quality and strength . Can provide a theoretical basis for CFRP tendons durability design , to provide theoretical guidance to improve the efficiency of the FRP bars in harsh conditions .

The corrosion protection of AA2024-T3 aluminium alloy by leaching of lithium-containing salts from organic coatings

2015 ◽  
Vol 180 ◽  
pp. 511-526 ◽  
Author(s):  
Peter Visser ◽  
Yanwen Liu ◽  
Xiaorong Zhou ◽  
Teruo Hashimoto ◽  
George E. Thompson ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Salt Spray ◽  
Protective Layer ◽  
Middle Layer ◽  
Organic Coating ◽  
Organic Coatings ◽  
Inhibition Mechanism ◽  
Dense Layer ◽  
Neutral Salt ◽  
Protective Layers

Lithium carbonate and lithium oxalate were incorporated as leachable corrosion inhibitors in model organic coatings for the protection of AA2024-T3. The coated samples were artificially damaged with a scribe. It was found that the lithium-salts are able to leach from the organic coating and form a protective layer in the scribe on AA2024-T3 under neutral salt spray conditions. The present paper shows the first observation and analysis of these corrosion protective layers, generated from lithium-salt loaded organic coatings. The scribed areas were examined by scanning and transmission electron microscopy before and after neutral salt spray exposure (ASTM-B117). The protective layers typically consist of three different layered regions, including a relatively dense layer near the alloy substrate, a porous middle layer and a flake-shaped outer layer, with lithium uniformly distributed throughout all three layers. Scanning electron microscopy and white light interferometry surface roughness measurements demonstrate that the formation of the layer occurs rapidly and, therefore provides an effective inhibition mechanism. Based on the observation of this work, a mechanism is proposed for the formation of these protective layers.

Study on Impact-Resistant Performance of Structural Wall with Different Protective Layers

2013 ◽  
Vol 838-841 ◽  
pp. 618-621
Author(s):  
Run Lin Yang ◽  
Li Zhao ◽  
Juan Hua Zhou ◽  
Yuan Li
Keyword(s):  
Protective Layer ◽  
Impact Loads ◽  
Protective Effects ◽  
Structural Members ◽  
Concrete Wall ◽  
Structural Wall ◽  
Protective Layers ◽  
Traditional Design ◽  
Protective System ◽  
Target Wall

Traditional design of structural members is considered less collision effects, so it may be possible to cause damage due to impact loads. In view of this, impact-resistant performance of the concrete wall with different protective layers was analyzed. In the process of the numerical simulation, the observed walls with three different measures including the unprotected, the rigid protective and the flexible protective one were considered separately. Protective effects of the different measures were compared and analyzed by observing the stress, the strain, the velocity and acceleration of the target wall. Numerical results show that the flexible protective system works better. The flexible protective layer of the wall may have a significant impact on the protective effect such as suppression of the peak impact response.

scholarly journals Experimental insight into the chemical corrosion mechanism of copper with an oil-in-water emulsion solution

RSC Advances ◽  
2018 ◽  
Vol 8 (18) ◽  
pp. 9833-9840 ◽  
Author(s):  
Xudong Yan ◽  
Jianlin Sun ◽  
Yanan Meng
Keyword(s):  
Corrosion Mechanism ◽  
Metal Working ◽  
Working Process ◽  
Water Emulsion ◽  
Chemical Corrosion ◽  
Oil In Water ◽  
Copper Storage ◽  
Oil In Water Emulsion ◽  
Insight Into

Chemical corrosion mechanism of copper in an oil-in-water (O/W) emulsion is worthy of study since it would contribute to emulsion-lubrication in a metal-working process and for copper storage.

Protective afteraction of inhibitor IFKhAN-92 during chromium-nickel stainless steel corrosion in sulfuric acid

2020 ◽  
pp. 23-31
Author(s):  
Ya.G. Avdeev ◽  
◽  
Yu.B. Makarychev ◽  
D.S. Kuznetsov ◽  
◽  
...  
Keyword(s):  
Stainless Steel ◽  
Sulfuric Acid ◽  
Steel Surface ◽  
Outer Part ◽  
Protective Layer ◽  
Steel Corrosion ◽  
Metallic Phase ◽  
Organic Layer ◽  
Polymer Complex ◽  
Protective Layers

The protective polymolecular layers formed on the surface of 12Kh18N10T chromium-nickel stainless steel in a solution of sulfuric acid with IFKhAN-92 (a triazole derivative) added is shown to have the protective afteraction in the same acid. The effectiveness of the protective afteraction of mixtures containing IFKhAN-92 is determined by the time of preliminary adsorption of the inhibitor, its concentration in the solution of preliminary adsorption, the temperatures of the solution of preliminary adsorption of the inhibitor and the background acid solution. The layers formed on steel by the IFKhAN-92 + KNCS and IFKhAN-92 + KI compositions have the highest protective afteraction. These layers protect steel at 80 °С in the background 2 M H2SO4. An increase in temperature of the solutions of preliminary adsorption of inhibitors enhances their protective afteraction, which indicates chemical nature of the interaction of the inhibitor molecules with the steel surface. The composition and the structure of the protective layers formed on the steel surface was studied by XPS analysis. The protective layer is chemically bonded to the phase of hydroxides and oxides of Fe, Cr and Ni, adjacent to the metallic phase. The lower part of the protective polymolecular layer of the organic inhibitor consists of a polymer complex formed by molecules of IFKhAN-92 and metal cations (Fe, Cr and Ni). The outer part of the protective organic layer consists of physically adsorbed molecules IFKhAN-92, easily removed from the metal surface during ultrasonic washing of samples.

The Study of Microstructure and Properties of Al Diffusion Coating on Inconel 713LC

2011 ◽  
Vol 465 ◽  
pp. 282-285 ◽  
Author(s):  
Simona Hutařová ◽  
Martin Juliš ◽  
Karel Obrtlík ◽  
Marta Kianicová ◽  
Tomáš Podrábský ◽  
...  
Keyword(s):  
High Temperature ◽  
Diffusion Coating ◽  
Protective Layer ◽  
Life Time ◽  
Fatigue Properties ◽  
Nickel Base Superalloy ◽  
Polycrystalline Nickel ◽  
Energy Dispersion Spectroscopy ◽  
Microstructure And Properties ◽  
Protective Layers

Protective layers are used to improve high temperature performance of structural materials. However, the effect of coatings on mechanical and fatigue properties is not sufficiently known because it is a combination of many factors as high-temperature exposure time, thermal cycle and coating deposition technique. Interactions between the coating and the substrate under high-temperature conditions influence the life time of coated blades. This paper is focused on the study of microstructure and properties of aluminide protective layers deposited on cast polycrystalline nickel base superalloy Inconel713LC. The light microscopy with image analyses and scanning electron microscopy with energy dispersion spectroscopy were used. The surface treated specimens exposed at 800 °C in air and cylindrical specimens with protective layer cyclically loaded under strain control at 800 °C in air were studied. Experimental data on thickness, uniformity and chemical analysis of individual phases are obtained for as-coated specimens, for specimens exposed to 800 °C for 500 hours in air and for specimens fatigued to fracture at 800 °C in air.

Chemical Corrosion of Lead-Iron Phosphate Glass

1987 ◽  
Vol 112 ◽  
Author(s):  
Werner Lutze ◽  
P. Schubert
Keyword(s):  
Corrosion Rate ◽  
Dissolution Kinetics ◽  
Iron Phosphate ◽  
Corrosion Mechanism ◽  
Chemical Corrosion ◽  
Total Mass Loss ◽  
Glass Corrosion ◽  
Activity Measurements ◽  
Doped Glasses ◽  
In The Beginning

AbstractThis study provides experimental data on the corrosion of lead-iron phosphate (LIP) glass (6.4 wt% LWR waste loading) and the first comparison with the dissolution kinetics of borosilicate (BS) nuclear waste glass (all experiments at 90°C). Based on previous experiments the hypothesis was made that the alteration phenomena and the corrosion mechanism are analogous to what is known for BS glasses. The corrosion rate was found to be constant, 0.06gm−2d−1, at high flow rates (MCC 5 type test), based on total mass loss and on ion conductivity measurements in the leachate. In an MCC 1 type experiment, doped glasses (32p, 210Pb and 137Cs, respectively) were corroded and the release of activity into solution monitored. The release rates were 0.05gm−2 d−1 in the beginning, but decreased drastically when the solution became saturated with respect to Pb(OH)2 and Pb3 (PO4)2. Glass corrosion continued at a low rate as indicated by Cs activity measurements. The higher chemical durability of the LIP glass vs. BS glasses in DI water is a result of a smaller initial corrosion rate (10 to 10O×) and the fact that the saturation concentration is lower for LIP glass, i. e. it takes less dissolved glass (10 to 50×) to reach saturation than in the case of BS glass.

Plasma Display Materials

MRS Bulletin ◽  
2002 ◽  
Vol 27 (11) ◽  
pp. 898-902 ◽  
Author(s):  
Kinzo Nonomura ◽  
Hidetaka Higashino ◽  
Ryuichi Murai
Keyword(s):  
Large Scale ◽  
Protective Layer ◽  
Operating Conditions ◽  
Protective Layers ◽  
Blue Phosphor ◽  
Wide Range ◽  
Plasma Display ◽  
Deterioration Mechanism ◽  
Discharge Gas ◽  
Gas Efficiency

AbstractRecent trends in the development of plasma display panels (PDPs) are reviewed in this article with special emphasis on materials. New developments in the panel structure, discharge gases and phosphors used, and drive methods have improved many of the display characteristics over a wide range of operating conditions. As a result, much progress has been seen in large-scale panel development; for example, 50-in. and 61-in. PDPs have been commercialized. Improvements in phosphor longevity, discharge gas efficiency, and characteristics of the protective layers can be attributed in part to materials solutions. The longevity of the blue phosphor has been improved by the development of new materials and a greater understanding of the phosphor deterioration mechanism. The luminous efficiency has been greatly increased by the use of high-density Xe gas. The protective-layer characteristics have been improved as a result of advancements in processes, materials, and analytical methods.

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