Corrosion Hazard Research Articles

HILDCAA‐Related GIC and Possible Corrosion Hazard in Underground Pipelines: A Comparison Based on Wavelet Transform

AbstractHigh‐intensity long‐duration continuous auroral electrojet activities (HILDCAAs) are recognized as the continuous (duration >2 days) auroral electrojet activities (AE > 1,000 nT) caused by interplanetary Alfvén waves driving magnetic reconnection at the Earth's magnetopause. This paper focuses on the study of geoeffectiveness of HILDCAA on the basis of associated geomagnetically induced currents (GICs) and pipe‐to‐soil voltage (PSV) observed in an underground pipeline at Finnish Natural Gas Station, Mäntsälä. In this study, 113 HILDCAAs with different interplanetary sources (72 corotating interaction region‐storm preceded, 29 interplanetary coronal mass ejection‐storm preceded, and 12 nonstorm) have been selected and their possible contributions in underground pipeline corrosion have been quantitatively compared by assessing GIC/PSV profiles for each of these events. In addition, the spectral characteristics of GIC during these events have been studied using continuous wavelet transforms. The Morlet wavelet has been applied to 10‐s modeled GIC data corresponding to each event to explore the main band structures and the periodicities found in GIC spectrum. GIC/PSV modeling is based on plane wave method and distributed source transmission line analogy between pipelines and electric circuits. HILDCAAs are found to drive a small‐amplitude, but continuous, fluctuation in GIC throughout the event duration of several days. This makes the cumulative effect of HILDCAAs in pipeline corrosion noteworthy. The spectral analysis shows that GIC possesses both short‐term, as well as continuous, power distribution with different periodicities. CIR‐preceded HILDCAAs are found to be more geoeffective while taking associated GIC and PSV into account. Possible physical explanations supporting the results have been presented.

Monitoring and testing corrosion and responsive behaviour in galvanic systems.

Testing methods for corrosion prevention in structures have, historically, been based on the steel polarising from the protective current. Modern galvanic systems aim to protect the steel by restoring the protective alkaline environment, rather than through polarisation. Since 2012 standard guidelines allow for alternative testing to be used [1]. Scientific testing of galvanic systems will be discussed looking at the nature of constant potential galvanic systems and comparing them to the traditional constant current impressed systems, looking in particular at unique anode behaviours such as low median current during times of low corrosion risk and responsive behaviour during corrosion hazards. This work lays out a protocol for the evaluation and testing of existing galvanic corrosion protection (CP) systems in reinforced concrete through the lens of various real-world studies. Data taken from over a decade of monitored systems are used to support the protocol. Modern testing strategies such as 2-dimensional relative potential mapping and corrosion rate monitoring will measure the steel's corrosion. Galvanic currents rise and fall with corrosion risk providing protection while ensuring a long life to the design.

Case studies of hybrid and galvanic systems on bridge structures

Corrosion of steel in bridge structures is a growing issue worldwide. Case studies of galvanic and hybrid systems show the diverse range of challenges and corrosion hazards that are faced during the design of these systems. Data from these case studies show the effectiveness of this approach. Hybrid systems have been utilised in controlling corrosion during refurbishment work on bridges for over a decade. Galvanic systems have been around much longer. By utilising these systems individually or together there is great flexibility in design. This allows intensive concrete restoration from a hybrid system alongside the maintenance of repairs in lower risk areas from galvanic anodes. This paper presents case studies covering hybrid and galvanic systems applied to bridge structures. Included is a prestressed concrete bridge in a tidal environment, we believe to be the first of its kind fitted with a hybrid system. Tidal considerations and flooding are key challenges in corrosion mitigation. Data shows the systems are particularly effective in these transitory environments reacting rapidly to increased risk.

МЕТОДИЧЕСКИЙ ПОДХОД К ОБЕСПЕЧЕНИЮ РАБОТОСПОСОБНОСТИ МЕТАЛЛОКОНСТРУКЦИЙ В УСЛОВИЯХ КОРРОЗИОННОЙ ОПАСНОСТИ

The process has been analyzed of monitoring of structure and installation process safety under corrosion hazard of building facilities. A high level of wear and service limits of structures of buildings and installations are the real threat, which increases probability of a loss. The principles are analyzed of assurance of process safety of structures and installations as an integral structural component of the enterprise safety. It is shown that the development of measures of the reliability assurance program comprises the qualimetric monitoring and risk diagnostics of the determining parameters of structural corrosion state. As used here, a methodology is proposed for assessing serviceability of corrosive structures taking into account the requirements of the process approach to quality and safety management based on the principles of DMAIC (Define, Measure, Analyze, Improve and Control). Classified are the signs of serviceability based on the safety class of systems of structure corrosion protection to justify efficiency of measures for structure maintenance based on their actual state. Methods are theoretically and experimentally justified of redundancy of means of primary and secondary corrosion protection of structural steel. A practical example is presented of setting and solving the direct and inverse problems of the design calculation of structure survivability under corrosion hazard.

A Multi-Hazard Probabilistic Framework for Quantifying Bridge Failure Risk Considering Climate Change

Climate change has recently been recognized as a significant factor that can drive changes to current design and life-cycle assessment practices of infrastructure systems. The instability in temperature profiles and precipitation patterns in recent decades indicate that the future flood hazard occurrence rate may not necessarily follow historical trends. In addition to the impact of climate change on flood hazard occurrence rate and the associated scour progression, it could also affect the corrosion propagation in structural components. This paper presents a probabilistic framework for quantifying the multi-hazard failure risk of bridges under gradual and sudden deterioration considering climate change. Downscaled climate data adopted from the global climate models are employed to predict the future streamflow and temperature profiles at a given location. These profiles are subsequently used to quantify future failure probability and risk under corrosion and flood hazard. The proposed framework is illustrated on an existing bridge located in Oklahoma.

High energy oxidation and organosolv solubilization for high yield isolation of cellulose nanocrystals (CNC) from Eucalyptus hardwood

Cellulose nanocrystals (CNC) have been widely used as responsive materials, chiral templates, and tough nano-composites due to its unparalleled properties. Acid and enzyme hydrolyses are extensively employed to prepare CNC. These traditional approaches exhibit inherent limitations of corrosion hazards, time-consuming process, and/or low yield. Herein, irradiation oxidation and organosolv solubilization are conducted to cause rapid degradation with simultaneous crystallization of cellulose to achieve approx. 87% yield of CNC. The morphology, spectroscopic, and stability properties of the as-prepared CNC are characterized through UV-vis spectroscopy, zetal potential, XRD, TEM, DLS, GPC, FT-IR and TGA techniques. The resultant CNC suspension presents unique property with high stability after 9 months storage at 4 °C. Moreover, CNC liquid crystal phase is successfully generated by addition of anions or cations solution to the CNC aqueous dispersion without stirring. The innovative approach in this work opens an avenue to obtain CNC directly from lignocellulosic biomass through irradiation oxidation and organosolv solubilization without acid hydrolysis and washing procedure.

Usefulness of the EpiSkin™ reconstructed human epidermis model within Integrated Approaches on Testing and Assessment (IATA) for skin corrosion and irritation

Predictive capacity of the EpiSkin™ model was evaluated on 87 chemicals using the Bottom-Up and the Top-Down testing approaches recommended within Integrated Approach on Testing and Assessment for the identification of both skin irritation and corrosion hazards. Classified (UN GHS Cat. 1 and Cat. 2) chemicals were identified with a very high sensitivity (≥94%) and the non-classified (UN GHS Cat. 3 and No Cat.) chemicals with an appropriate specificity (70%). Very high sensitivities were obtained for the identification of Cat. 1 chemicals (≥98%), very high specificities for non-Cat. 1 chemicals (93%), and accuracies of −95% for the identification of skin corrosives vs. non-corrosives by both approaches. Overall accuracies of 72% were found for predicting the single (sub)categories: non-classified, Cat. 2, Subcat. 1B/1C and Subcat. 1A. Results indicated the testing strategies to be more predictive than the individual assays on a conservative safety approach. Finally, no extreme misclassifications (no under-prediction of in vivo Subcat. 1A as non-Cat. 1, and no over-prediction of non-classified chemical as Subcat. 1A) occur. These findings, independently of the approach used, confirm the usefulness of the EpiSkin™ in vitro model for a safe prediction of the skin irritant and corrosive hazards of chemicals.

Research Regarding Capacitor Discharge Stud Welding with Tip Ignition on Galvanized Thin Sheets

Arc stud welding is a widely used welding process used to fix joints like studs, screws, pins, or similar elements on a wide variety of products. The process is mainly characterized by simplicity, high welding productivity, very good welding joint quality, low cost price, easy welding equipment and easy to handle, flexibility. The process successfully replaces other assembly methods such as: threaded assembly, riveting, classic arc welding or pressure welding and soldering. The paper proposes to establish welding technology for M5 x 35 mm steel stud with tip ignition and electric charge stored in capacitors on thin galvanized steel (s <1 mm thick). The main problem of welding galvanized steel is vaporization of zinc on the surface of the sheet which produces pores, splashes and very toxic fumes. This vaporization produces also the corrosion hazard in the surface of the sheet. Welding technology will be applied to joint stud on the cover of an air filter.

A review of recent researches on Bunsen reaction for hydrogen production via S–I water and H2S splitting cycles

Abstract The Bunsen reaction is the center reaction for both the sulfur–iodine water splitting cycle for hydrogen production and the novel hydrogen sulfide splitting cycle for hydrogen and sulfuric acid production from the sulfur-containing gases. This paper reviews the research progress of the Bunsen reaction in recent 10–15 years. Researches were initially focused on the optimization of the operating conditions of the conventional Bunsen reaction requiring excessive water and iodine to improve the products separation efficiency and to avoid the side reactions and iodine vapor deposition. Alternative methods including electrochemical methods, precipitation methods, and non-aqueous solvent methods had their respective advantages, but still faced challenges. In development of the technology of H2S splitting cycle, dissolving iodine in toluene solvent could render the Bunsen reaction to occur with the flowable I2 stream at ambient temperature such that the side reactions and iodine vaporization can be avoided and the corrosion hazard lessened. It also prevented the Bunsen reaction from using excessive iodine and water. The products from the Bunsen reaction including HI, H2SO4, H2O, and toluene could be directly electrolyzed.

Pickering emulsion-based fabrication of epoxy and amine microcapsules for dual core self-healing coating

Facile and efficient encapsulation of epoxy and tetraethylenepentamine (TEPA) in polyurea (PU) microcapsules are accomplished with Pickering emulsion templates by one-step, interfacial polymerization. The formation of microcapsule is deftly achieved by lightly shaking Pickering emulsions. The whole process is time andenergy saving hardly with any waste and residual. Epoxy microcapsules keep the spherical shape with core content of more than 90 wt%. Amine microcapsules shrink a little for evaporation of water and the conserved TEPA after air-dried is 82.1 wt%. The shell walls of two microcapsules are about 1 μm. With the protection of PU shells, both microcapsules exhibit excellent thermal resistance. Furthermore, self-healing function of epoxy and amine microcapsules is measured by incorporating microcapsules into epoxy coating, and tested by brine-submersion corrosion-accelerating experiment. The dual core self-healing coatings demonstrate excellent self-repairing performance with the crack of embedded microcapsules and reaction between epoxy and amine. The core materials can outflow from microcapsules and form isolations for metal substrate from corrosion hazard, therefore, make for good self-repairing and preserving function of the self-healing coating.

Internal corrosion hazard assessment of oil & gas pipelines using Bayesian belief network model

A substantial amount of oil & gas products are transported and distributed via pipelines, which can stretch for thousands of kilometers. In British Columbia (BC), Canada, alone there are over 40,000 km of pipelines currently being operated. Because of the adverse environmental impact, public outrage and significant financial losses, the integrity of the pipelines is essential. More than 37 pipe failures per year occur in BC causing liquid spills and gas releases, damaging both property and environment. BC oil & gas commission (BCOGS) has indicated metal loss due to internal corrosion as one of the primary causes of these failures. Therefore, it is of a paramount importance to timely identify pipelines subjected to severe internal corrosion in order to improve corrosion mitigation and pipeline maintenance strategies, thus minimizing the likelihood of failure. To accomplish this task, this paper presents a Bayesian belief network (BBN)-based probabilistic internal corrosion hazard assessment approach for oil & gas pipelines. A cause-effect BBN model has been developed by considering various information, such as analytical corrosion models, expert knowledge and published literature. Multiple corrosion models and failure pressure models have been incorporated into a single flexible network to estimate corrosion defects and associated probability of failure (PoF). This paper also explores the influence of fluid composition and operating conditions on the corrosion rate and PoF. To demonstrate the application of the BBN model, a case study of the Northeastern BC oil & gas pipeline infrastructure is presented. Based on the pipeline's mechanical characteristics and operating conditions, spatial and probabilistic distributions of corrosion defect and PoF have been obtained and visualized with the aid of the Geographic Information System (GIS). The developed BBN model can identify vulnerable pipeline sections and rank them accordingly to enhance the informed decision-making process.

Seismic Response for a Reinforce Concrete Specimen Considering Corrosive Hazards

This study is aim to evaluate the dynamic response variation of the scale-down reinforced concrete frame specimen under accelerated corrosion conditions. The specimens achieved the accelerated corrosion test by immersing in the accelerated corrosion test. Open circuit potential, corrosion rate, natural frequencies, displacements, accelerations and response spectral curves were tested and discussed. Test results presented that the corroded reinforced concrete specimens presented the changes in the dynamic response especially natural frequencies and response spectrum. This study provided further insight on the variation of seismic response behaviors in the deteriorated reinforced concrete structures and hoped to useful for structural assessments and appraisals applied to full-scale structures.

Protection of bridges against stray current corrosion

A case study of Siennicki Bridge stray current corrosion hazard is presented. A corrosion risk was caused by incorrectly designed tram line traction which goes over the bridge. No dielectric insulation between running rails and bridge steel construction was used. A variety of protection methods against stray currents are described. Characteristics of the endangered bridge were described. Impressed current cathodic protection system against stray currents was proposed and designed at the Department of Electrochemistry, Corrosion and Materials Engineering, Gdansk University of Technology. Coupon technique measurements and potential measurements were performed to verify the effectiveness of the protection system.

Effect of Acidified Feronia elephantum Leaf Extract on the Corrosion Behavior of Mild Steel

Mild steel is used as a structural material for pipes, tank, reaction vessels, etc. which are known to corrode invariably in contact with various solvents. From the view point of a nation’s economy and financial implications of corrosion hazard, it is necessary to adopt appropriate means and ways to reduce the losses due to corrosion. The use of eco-friendly corrosion inhibitors are increasing day by day. Feronia elephantum leaf extract (FELE) has been tested as eco-friendly corrosion inhibitor for A262 mild steel in 1 M H2SO4 and 1 M HCl solutions using non-electrochemical (Gravimetric, X-ray diffraction analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy) and electrochemical techniques (open circuit potential, potentiostatic polarization, and electrochemical impedance measurements). The protection efficiency is found to increase with increase in FELE concentration but decrease with temperature, which is suggestive of physical adsorption mechanism. The adsorption of FELE on mild steel surface obeys the Langmuir adsorption isotherm. SEM results confirm the formation of a protective layer by FELE over mild steel surface.

Leakage Mechanism of the Wastewater Dam in Metal Mine and its Anti-Seepage Technology

The acid mine drainage has the widest pollution range and biggest harm degree, which forms the potential corrosion hazards to sewage dams in mental mine. Based on the investigation and analysis of the acid mine drainage, the evolution law influence of physical and mechanical properties and leakage mechanism of sewage dam is revealed under the action of the acid mine drainage. In order to prolong its service life and insure the safe operation of the construction engineering, the program of concrete anti-seepage wall with coal fly ash is adopted, which can improve the impermeability and structure of concrete, enhancing the anti-seepage wall durability under acidic environment, providing the basis of scientific data and technical basis for acid mine water environment of basic construction.

PROBABILISTIC TIME VARIANT ASSESSMENT OF THIN-WALLED STEEL MEMBERS UNDER ATMOSPHERIC CORROSION ATTACK

Atmospheric corrosion is a relevant problem for steel structures and components exposed in aggressive environment in case of poor and/or unfeasible maintenance and inspection during service life. As for thin-walled members, the corrosion hazard can be exacerbated due to the thin thickness of components and the coupled effect between corrosion and buckling can significantly reduce the structural capacity of such structures. Following these considerations, this paper presents a study on the reliability of a thin-walled steel section subjected to the damage induced by atmospheric corrosion in outdoor environments, combining predictive corrosion models for metals with structural reliability applications. A general procedure for the evaluation of the time variant capacity is proposed and discussed in detail. Finally, an application to a C-lipped cold formed section is presented and a reliability analysis of the deteriorating section is carried out to evaluate the coupled effect of corrosion and buckling, according to the proposed procedure.

Computer Simulation of High Temperature Corrosion Hazard of Anode Steel Stubs in Aluminium Electrolysis Cell

In the industrial production of primary aluminium process, the high temperature gaseous and the molten cryolite-alumina salt electrolyte will corrosion anode steel stubs. High temperature corrosion products of the stub are analyzed by SEM-EDX. Corrosion products consist of the mixed F, O, Na and Fe, etc. From computer simulation, high temperature corrosion of anode stubs will lead steel stubs current to inconsequence, cell voltage to high, anode consumption to inequality, etc. The current efficiency, current consumption and life of electrolysis cell will change to poor.

Rate of corrosion of waterwalls in supercritical pulverised fuel boilers

Rate of corrosion of waterwalls in supercritical pulverised fuel boilers This paper presents an analysis of the corrosion hazard in the burner belt area of waterwalls in pulverised fuel (PF) boilers that results from low-NOx combustion. Temperature distributions along the waterwall tubes in subcritical (denoted as SUB) and supercritical (SUP) boilers were calculated and compared. Two hypothetical distributions of CO concentrations were assumed in the near-wall layer of the flue gas in the boiler furnace, and the kinetics of the waterwall corrosion were analysed as a function of the local temperature of the tubes. The predicted rate of corrosion of the boiler furnace waterwalls in the supercritical boilers was compared with that of in the subcritical boilers.

Simulation of Radioactive Corrosion Product in Primary Cooling System of Japanese Sodium-Cooled Fast Breeder Reactor

Radioactive Corrosion Product (CP) is a main cause of personal radiation exposure during maintenance with no breached fuel in fast breeder reactor (FBR) plants. The most important CP is 54Mn and 60Co. In order to establish techniques of radiation dose estimation for radiation workers in radiation-controlled areas of the FBR, the PSYCHE (Program SYstem for Corrosion Hazard Evaluation) code was developed. We add the Particle Model to the conventional PSYCHE analytical model. In this paper, we performed calculation of CP transfer in JOYO using an improved calculation code in which the Particle Model was added to the PSYCHE. The C/E (calculated / experimentally observed) value for CP deposition was improved through use of this improved PSYCHE incorporating the Particle Model. Moreover, among the percentage of total radioactive deposition accounted for by CP in particle form, 54Mn was estimated to constitute approximately 20 % and 60Co approximately 40 % in the cold-leg region. These calculation results are consistent with the measured results for the actual cold-leg piping in the JOYO.

Principles of proving corrosion risk of building structures, fabrics and constructions

Procedural problems of justification of the intelligent choice of corrosion protection measures at the design stage are considered in the given work. The paper is aimed at formulating principles of economic management of corrosion protection measures efficiency based on risk assessment according to corrosion hazard criteria. Application of the corrosion risk criterion gives an opportunity to make the economic justification of the requirements to the choice of the primary and secondary protection design characteristics.