Carbon Steel Corrosion and Cathodic Protection Data in Deep North Atlantic Ocean

CORROSION ◽  
10.5006/3552 ◽  
2020 ◽  
Vol 76 (11) ◽  
Author(s):  
Erwan Diler ◽  
Nicolas Larché ◽  
Dominique Thierry
Keyword(s):  
Carbon Steel ◽  
Atlantic Ocean ◽  
Cathodic Protection ◽  
Cold Water ◽  
Potential Temperature ◽  
Natural Seawater ◽  
Cathodic Current ◽  
Deposit Formation ◽  
X Ray ◽  
Calcareous Deposit

Many parameters may influence the corrosion and the cathodic protection current demand in natural seawater. These are potential, temperature, dissolved oxygen content, biofilm and fouling activity, hydrostatic pressure, and calcareous deposit formation. In this study, the influence of the exposure depth on the corrosion, cathodic protection current demand, and nature of the calcareous deposit formed on carbon steel was investigated at 1,020 m and 2,020 m depth. For this purpose, a set of coupons, cathodic protection, and environmental sensors were exposed in Azores in the Atlantic Ocean for 11 months. The higher corrosion rate and current density observed at 1,020 m can be explained by the higher temperature and oxygen diffusion. The cathodic current demand decrease with time can be attributed to the calcareous deposit formation. The current densities after 11 months are in agreement with the literature with 143 mA/m2 and 124 mA/m2 at 1,020 m and 2,020 m depth. Calcareous deposits formed, characterized by Raman spectroscopy, x-ray diffraction, and scanning electron microscopy/electron dispersive x-ray spectroscopy, highlight (i) the favored formation of calcite and hydrocalcite at the expense of aragonite in deep and cold water, (ii) the presence of a thin deposit after 11 months, (iii) the decrease of the Ca/Mg ratio with immersion depth, (iv) the presence of CaMgCO3 compounds, and (v) a higher decrease of the current demand with time in deep water, suggesting the formation of a more protective deposit. The capacity for aluminum-gallium and aluminum-indium galvanic anode were in agreement with the literature for long-term exposures.

Cathodic protection of carbon steel in natural seawater: Effect of sunlight radiation

2009 ◽  
Vol 54 (26) ◽  
pp. 6472-6478 ◽  
Author(s):  
Alessandro Benedetti ◽  
Luca Magagnin ◽  
Francesca Passaretti ◽  
Elisabetta Chelossi ◽  
Marco Faimali ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Cathodic Protection ◽  
Natural Seawater ◽  
Sunlight Radiation

Influence of Cathodic Protection Parameters on Calcareous Deposit Formation

CORROSION ◽  
1988 ◽  
Vol 44 (12) ◽  
pp. 887-891 ◽  
Author(s):  
R. U. Lee ◽  
J. R. Ambrose
Keyword(s):  
Cathodic Protection ◽  
Deposit Formation ◽  
Calcareous Deposit

Characterization of the Corrosion Products Formed on Carbon Steel in Qinghai Salt Lake Atmosphere

CORROSION ◽  
2007 ◽  
Vol 63 (7) ◽  
pp. 640-647 ◽  
Author(s):  
Q. X. Li ◽  
Z. Y. Wang ◽  
W. Han ◽  
E. H. Han
Keyword(s):  
Carbon Steel ◽  
Salt Lake ◽  
Electrochemical Techniques ◽  
Corrosion Products ◽  
Infrared Transmission ◽  
X Ray Diffraction ◽  
Cathodic Current ◽  
Free Corrosion Potential ◽  
X Ray

Abstract The corrosion products formed on carbon steel exposed to the Qinghai Salt Lake atmosphere for 12 months was studied using scanning electron microscopy (SEM), electron probe microanalysis (EPMA), x-ray diffraction (XRD), infrared transmission spectroscopy (IRS), and electrochemical techniques. The rust was mainly composed of akaganeite (β-FeOOH), iron hydroxychloride (Fe8[O,OH]16Cl1.3), and a little lepidocrocite (γ-FeOOH). Amorphous δ-FeOOH was only on the downward surface, and the upward surface was corroded more severely than the downward surface. Cl, Mg, and Si foreign elements were rich in the rust. The rust on carbon steel decreased anodic dissolution and increased cathodic current. A low free corrosion potential of the rusted electrode and a very small value of rust resistance (RR) demonstrated that the rust was nonprotective in the Qinghai Salt Lake atmosphere.

INFLUENCE THE QUENCHING AND TEMPERING ON THE MICROSTRUCTURE, MECHANICAL PROPERTIES AND SURFACE ROUGHNESS, OF MEDIUM CARBON STEEL

2018 ◽  
Vol 18 (1) ◽  
pp. 125-135
Author(s):  
Sattar H A Alfatlawi
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Surface Roughness ◽  
Carbon Steel ◽  
Cold Water ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
Heating And Cooling ◽  
Treatment Processes ◽  
Quenching And Tempering

One of ways to improve properties of materials without changing the product shape toobtain the desired engineering applications is heating and cooling under effect of controlledsequence of heat treatment. The main aim of this study was to investigate the effect ofheating and cooling on the surface roughness, microstructure and some selected propertiessuch as the hardness and impact strength of Medium Carbon Steel which treated at differenttypes of heat treatment processes. Heat treatment achieved in this work was respectively,heating, quenching and tempering. The specimens were heated to 850°C and left for 45minutes inside the furnace as a holding time at that temperature, then quenching process wasperformed in four types of quenching media (still air, cold water (2°C), oil and polymersolution), respectively. Thereafter, the samples were tempered at 200°C, 400°C, and 600°Cwith one hour as a soaking time for each temperature, then were all cooled by still air. Whenthe heat treatment process was completed, the surface roughness, hardness, impact strengthand microstructure tests were performed. The results showed a change and clearimprovement of surface roughness, mechanical properties and microstructure afterquenching was achieved, as well as the change that took place due to the increasingtoughness and ductility by reducing of brittleness of samples.

Commercial aqueous additives as used eco-friendly corrosion inhibitors for carbon steel in natural seawater

2020 ◽  
Vol 65 (1) ◽  
pp. 77-82
Author(s):  
Simona CAPRARESCU ◽  
◽  
Violeta PURCAR ◽  
Cristina MODROGAN ◽  
◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibitors ◽  
Natural Seawater

The study of the electrochemical properties of zinc-rich coating on the base of water sodium silicate

2019 ◽  
Vol 24 (4) ◽  
pp. 51-58
Author(s):  
Le Hong Quan ◽  
Nguyen Van Chi ◽  
Mai Van Minh ◽  
Nong Quoc Quang ◽  
Dong Van Kien
Keyword(s):  
Carbon Steel ◽  
Electrochemical Properties ◽  
Sodium Silicate ◽  
Cathodic Protection ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
Electrical Contact ◽  
Electrochemical Impedance Spectra ◽  
Pure Zinc ◽  
Electric Circuits

The study examines the electrochemical properties of a coating based on water sodium silicate and pure zinc dust (ZSC, working title - TTL-VN) using the Electrochemical Impedance Spectra (EIS) with AutoLAB PGSTAT204N. The system consists of three electrodes: Ag/AgCl (SCE) reference electrode in 3 M solution of KCl, auxiliary electrode Pt (8x8 mm) and working electrodes (carbon steel with surface treatment up to Sa 2.5) for determination of corrosion potential (Ecorr) and calculation of equivalent electric circuits used for explanation of impedance measurement results. It was shown that electrochemical method is effective for study of corrosion characteristics of ZSC on steel. We proposed an interpretation of the deterioration over time of the ability of zinc particles in paint to provide cathodic protection for carbon steel. The results show that the value of Ecorr is between -0,9 and -1,1 V / SCE for ten days of diving. This means that there is an electrical contact between the zinc particles, which provides good cathodic protection for the steel substrate and most of the zinc particles were involved in the osmosis process. The good characteristics of the TTL-VN coating during immersion in a 3,5% NaCl solution can also be explained by the preservation of corrosive zinc products in the coating, which allows the creation of random barrier properties.

scholarly journals Does galvanic cathodic protection by aluminum anodes impact marine organisms?

2020 ◽  
Vol 32 (1) ◽  
Author(s):  
Anna Maria Bell ◽  
Marcus von der Au ◽  
Julia Regnery ◽  
Matthias Schmid ◽  
Björn Meermann ◽  
...  
Keyword(s):  
Marine Environment ◽  
Cathodic Protection ◽  
Algal Growth ◽  
Wind Farms ◽  
Marine Organisms ◽  
Offshore Wind ◽  
Natural Seawater ◽  
Corophium Volutator ◽  
Offshore Wind Farms ◽  
Ecotoxicological Effects

Abstract Background Cathodic protection by sacrificial anodes composed of aluminum-zinc-indium alloys is often applied to protect offshore support structures of wind turbines from corrosion. Given the considerable growth of renewable energies and thus offshore wind farms in Germany over the last decade, increasing levels of aluminum, indium and zinc are released to the marine environment. Although these metals are ecotoxicologically well-studied, data regarding their impact on marine organisms, especially sediment-dwelling species, as well as possible ecotoxicological effects of galvanic anodes are scarce. To investigate possible ecotoxicological effects to the marine environment, the diatom Phaedactylum tricornutum, the bacterium Aliivibrio fischeri and the amphipod Corophium volutator were exposed to dissolved galvanic anodes and solutions of aluminum and zinc, respectively, in standardized laboratory tests using natural seawater. In addition to acute toxicological effects, the uptake of these elements by C. volutator was investigated. Results The investigated anode material caused no acute toxicity to the tested bacteria and only weak but significant effects on algal growth. In case of the amphipods, the single elements Al and Zn showed significant effects only at the highest tested concentrations. Moreover, an accumulation of Al and In was observed in the crustacea species. Conclusions Overall, the findings of this study indicated no direct environmental impact on the tested marine organisms by the use of galvanic anodes for cathodic protection. However, the accumulation of metals in, e.g., crustaceans might enhance their trophic transfer within the marine food web.

scholarly journals Effects of thermal treatments on characteristics and morphological variations in the deposits of urea-SCR systems

2021 ◽  
Author(s):  
Sadashiva Prabhu S ◽  
Kapilan Natesan ◽  
Nagaraj Shivappa Nayak
Keyword(s):  
Cyanuric Acid ◽  
Catalytic Reduction ◽  
Morphological Changes ◽  
Water Solution ◽  
Slight Variation ◽  
Gravimetric Analysis ◽  
Oxides Of Nitrogen ◽  
Deposit Formation ◽  
X Ray ◽  
Exhaust Gases

AbstractSelective catalytic reduction (SCR) systems are employed by automobile manufacturers for the abatement of environmental pollutants like oxides of nitrogen (NOx) emitted from exhaust gases of diesel engines. In SCR, the urea-water solution (UWS) is injected to exhaust gases in the form of a spray to generate the reducing agent NH3. Deposit formation at lower temperatures is a major concern with this technology. The deposits not only create backpressure but also leak NH3 to the environment as they deplete. It is very important to know the depletion characteristics of deposits formed at lower temperatures in order to assess the NH3 leakage to the environment when the engine exhaust gases attain higher temperatures. In the present work, deposits formed at a low-temperature range of 150–200°C for continuous run along with UWS injection were investigated. Additionally, they were aged at 300°C in the absence of UWS to check the variation in characteristics with the rise of temperature. By gravimetric analysis, it is inferred that the deposits formed at higher pre-age temperatures are less prone to depletion as the temperature increases. The elemental analysis using energy-dispersive X-ray spectroscopy (EDX) indicates slight variation in carbon, nitrogen and oxygen compositions for all the pre-age conditions. As an extended study, the byproducts at pre-age and post-age conditions were investigated through X-ray diffraction (XRD). The compounds like cyanuric acid (CYA) and biuret were not observed when pre-age samples were aged at 300°C. Instead, the compounds like ammelide, ammeline, triuret and melamine were observed. Scanning electron microscope (SEM) study revealed morphological changes in both pre-age and post-age samples. Further, the crystallinity variations were also observed for the changes in the heating cycles during deposit formation. The gravimetric analysis of deposits in pre-age and post-age conditions helps in predicting the amount of deposits for transient load cycles.

scholarly journals Elucidation of void defects by soft reduction in medium carbon steel via EBSD and X-ray computed tomography

2021 ◽  
pp. 109978
Author(s):  
Naqash Ali ◽  
Liqiang Zhang ◽  
Hongwei Zhou ◽  
Aonan Zhao ◽  
Chaojie Zhang ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Carbon Steel ◽  
Medium Carbon Steel ◽  
Medium Carbon ◽  
X Ray ◽  
Soft Reduction ◽  
Void Defects ◽  
X Ray Computed

scholarly journals Dislocation densities in a low-carbon steel during martensite transformation determined by in situ high energy X-Ray diffraction

2021 ◽  
Vol 800 ◽  
pp. 140249
Author(s):  
Juan Macchi ◽  
Steve Gaudez ◽  
Guillaume Geandier ◽  
Julien Teixeira ◽  
Sabine Denis ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Martensite Transformation ◽  
Low Carbon Steel ◽  
High Energy ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
X Ray ◽  
Dislocation Densities
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