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Erosion corrosion is encountered in many areas of industry and is a very complex phenomenon. In this study, it is aimed to investigate the effects of erosion corrosion in elbow pipes with different shear moduli, velocities of fluid, density of pipe using Ansys Workbench Explicit Dynamics module which is computer-aided and based on finite element. Statistical analyses were also performed to obtain the best flow parameters. SolidWorks program was used for three-dimensional studies considering elbow pipe design. The fluid properties and physical conditions were applied to the three-dimensional solid model in the pipe flow analysis. At the end of the dynamic analysis, erosion values (deformation) occurring in the elbow pipes were statistically compared to each other. [ABSTRACT FROM AUTHOR]

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, CrNi alloyed coating was deposited on Q235 low carbon steel by arc-added glow plasma depositing technique in order to increase the corrosion resistance property. It was found that the CrNi alloyed coating was composed of face-centered cubic Cr0.7Ni2.9Fe0.36 phase. The EDS results indicated that 7.3 μ m coatings were prepared which was bonded metallurgically with the substrate. The salt spray corrosion test result showed that the corrosion product film of coating was dense while the corrosion film of carbon steel was multilayered in morphology. The corrosion product film of CrNi coating reduced the corrosion rate. However, the corrosion product of Q235 with loose multi-layer structure increased corrosion process. The erosion corrosion properties of carbon steel and coating were tested in NaCl solution with different flowing speed through electrochemical test methods. The erosion corrosion results showed that the corrosion rate of carbon steel was increased in flowing NaCl solution. The corrosion product of CrNi coating could protect inner material in NaCl solution at flowing speed of 2 m·s − 1 to 6 m·s − 1 . [ABSTRACT FROM AUTHOR]

Copyright of Journal of Materials Engineering / Cailiao Gongcheng is the property of Journal of Materials Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Paint & Coatings Industry (0253-4312) is the property of Paint & Coatings Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the comprehensive performance of TC11 titanium alloy and make it more widely used in the field of oil and gas wells, cobalt oxide micro‐powder from 0 to 0.8 g·L−1 was added in the electrolyte. The effects of cobalt oxide micro‐powder concentration on properties of micro‐arc oxidation (MAO) coatings were analyzed by scanning electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and electrochemical workstation. With cobalt oxide micro‐powder increased, the oxide voltage increased, and the discharge coating micropores became more uniform. The increase in thickness and hardness also improved corrosion resistance. The comprehensive performance after added 0.6 g·L−1 of cobalt oxide was the best, with a doubling increase in thickness and hardness, reaching 32.1 µm and 721.2 HV, respectively. The corrosion rate reduced to 4.19 × 10−10 mm·a−1, which reduced by three orders of magnitude. In addition, the substrates and samples prepared with 0.6 g·L−1 cobalt oxidation were used for the erosion corrosion tests in different NaCl solutions, and it was found that the weight loss and rate of the MAO sample (slight corrosion) were lower than substrates, indicating that the cobalt oxide doped coatings had better corrosion resistance. [ABSTRACT FROM AUTHOR]

Copyright of Corrosion & Protection in Petrochemical Industry is the property of Corrosion & Protection in Petrochemical Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The corrosion occurred at the entrance pipeline of safety valve at acid water stripping tower top has been analyzed via macromorphology, material quality, metallographic examination and SEM, etc. The results show that the corrosion and perforation is caused typically by ammonium salt corrosion under scale, erosion corrosion and cavitation corrosion at presence of acid water and vapour. Thus, several countermeansures are given to solve the corrosion problems. It is helpful for reduction of corrosion, improvement of service life of pipeline at acid water stripping tower top, and ensurance of long-term safety production. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Changzhou University (Natural Science Edition) / Changzhou Daxue Xuebao (Ziran Kexue Ban) is the property of Editorial Department of Journal of Changzhou University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Erosion‐corrosion (E−C) is one of the most intense forms of metal degradation observed whenever a static metallic material is in contact with dynamic liquid. Efficiency of industrial plant mainly depends upon the condition of various components of the equipment. Collective mechanism of corrosion and erosion results in severe surface deterioration with heavy material loss due to synergistic effect. Erosion‐corrosion is mainly observed in the pipelines used in oil and gas industries, petroleum industries, heat exchanges and mainly in marine equipment. Free flowing saline water, containing different grades of sand particles adversely affect marine equipment. Numerous reports are available discussing the impact of erosion‐corrosion in chemical industries. Single report documenting all types of prototypes, comparative study of erosion corrosion of various engineering materials and control techniques is highly limited. This review gives vivid account of various types of prototypes, comparative study of erosion‐corrosion of various engineering materials, various factors affecting tribology of system and control techniques is a systematic way. Application of corrosion inhibitors appears to be an effective method to reduce erosion‐corrosion. This review highlights the importance of understanding the mechanism of erosion‐corrosion in industrial equipment and provides a succinct overview of erosion‐corrosion synergism. [ABSTRACT FROM AUTHOR]

Copyright of Kemija u Industriji is the property of Croatian Society of Chemical Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The project involved designing, constructing and commissioning a cathodic protection system for a selected spiral classifier operating at the KGHM Polska Miedź S.A. Ore Concentration Plant (O/ZWR). The authors developed a concept and assumptions regarding the corrosion protection of a large industrial device using a cathodic protection system with an external power source. Pre-project studies included conducting a trial polarization of one of the 28 classifiers operating at O/ZWR. The obtained results enabled the determination of the protective current demand required and the selection of a target polarization device, ensuring the flow of current with an intensity that guarantees that the required corrosion protection level will be achieved. The ultimately installed cathodic protection system consisted of an external cathodic protection current source with maximum output parameters of 50V/20A, a power supply system and a polarization anode system. Elements for monitoring corrosion occurring during system operation were installed, which employed reference electrodes of zinc (Zn) and silver chloride (Ag/AgCl) to measure the potential of the structure under cathodic protection. Furthermore, resistive corrosion sensors were installed to measure the steel corrosion rate under polarization conditions, making it possible to assess the effectiveness of the protection. The system will also be equipped with a prototype system for remote monitoring of the operation of the protection system, enabling online observation and analysis of settings and temporary indicators influencing the ongoing corrosion processes. [ABSTRACT FROM AUTHOR]

Copyright of Journal of National University of Defense Technology / Guofang Keji Daxue Xuebao is the property of NUDT Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chemical Engineering of Oil & Gas / Shi You Yu Tian Ran Qi Hua Gong is the property of PetroChina Southwest Oil & Gas Field Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

There has been a significant increase in the failure of pipes used for recirculating hot water systems installed in hospitals, apartment blocks, and hotels in recent years. The rise has occurred as these systems have increased in popularity, and thermostatic mixing valves have made the higher operating temperatures in recirculating systems safe. A common theme tends to be the continuous flow of water above 65°C (150°F) at velocities that have been found acceptable for non-continuous flow. Failures have been experienced in pipes made from both copper and polypropylene random copolymer. Explanations have been slow to emerge and are still subject to debate, particularly as to the initiating causes of pin-hole corrosion (one of the more common modes of failure). Since it is not possible to view the initiation of the pin hole, proof of the cause of the initiation is still unknown. There are indications from consistent correlations between operating conditions and the onset of pin-holing corrosion that are used by authorities as the basis of modifications to design and installation standards to minimize occurrence. This paper will cover some of the background, myths, and current thinking on the causes of the problem in both copper and polypropylene from the point of view of a forensic engineer trying to make sense of uncertain science and the complications of a problem that is transdisciplinary in nature. [ABSTRACT FROM AUTHOR]

In this study, the Fe-Cr-Ni-Si and WC alloy coatings were deposited on the polished 2Cr13 steel samples by using a laser cladding technique. The microstructure, tribology and erosion-corrosion resistance properties of laser cladding coatings were investigated, and the influence of WC proportion on properties of coatings were analyzed. The research results show that the ratio of WC in alloy powders affects obviously the tribology and erosion-corrosion resistance properties of laser cladding coatings, when the ratio of WC in alloy powders is 20%, alloy coating possesses excellent properties of hardness, wear-resisting and erosive-corrosive resistance, which can prolong effectively the operating life of equipment. [ABSTRACT FROM AUTHOR]

In this study, the Fe-Cr-Ni-Si and WC alloy coatings were deposited on the polished 2Cr13 steel samples by using a laser cladding technique. The microstructure, tribology and erosion-corrosion resistance properties of laser cladding coatings were investigated, and the influence of WC proportion on properties of coatings were analyzed. The research results show that the ratio of WC in alloy powders affects obviously the tribology and erosion-corrosion resistance properties of laser cladding coatings, when the ratio of WC in alloy powders is 20%, alloy coating possesses excellent properties of hardness, wear-resisting and erosive-corrosive resistance, which can prolong effectively the operating life of equipment. [ABSTRACT FROM AUTHOR]

Today, conventional machining with chip or machining without chip machining manufacturing methods is used to bring to the desired dimensions sizes the machines and equipment used in the industry. However, non-traditional manufacturing methods are used in cases where traditional machining manufacturing methods are inadequate. Cutting with water jet which is one of the non-traditional manufacturing methods is commonly used in several fields of industry. Unlike traditional manufacturing methods such as turning and milling, not using of a physical cutting tool is among the advantages of the method. Abrasive water jet manufacturing method was started to be applied by adding abrasive particles in the water jet. Apart from the superior properties of the method, possible damages occur in the water jet nozzle due to processes such as cutting or drilling by applying high pressure. Erosion-corrosion is the leading damage among these damages. In this study, the erosion-corrosion in the nozzle caused by high-pressure water and abrasive during the abrasive water jet cutting process was simulated in the computer environment. In this paper, the erosion rate in the nozzle was calculated as 6,90E-06 kg/m2 s. This value was converted as 0,30 mm (27,09 mm for yearly) via developed software for 100 h. [ABSTRACT FROM AUTHOR]

The initial processes that take place in the operating facilities of the pressure reduction station on natural gas do not remove all its pollutants, whether moisture or solid particles. Under such conditions, corrosion in pipelines, blockage of instrumentation equipment, and destruction of valves and regulators will be intensified, so it is necessary at distribution and pressure reduction stations to prevent gas pressure drop and damage to pipeline equipment, processes to separate solid particles. And liquefied droplets of natural gas. This report first defines natural gas flow erosion and then briefly describes the flow erosion using the Discrete Phase Method DPM and the Eulerian-Lagrangian biphasic flow, or the discrete phase abbreviated simulation using Ansys Fluent 2019R1 software. The gas-solid in the elbow deals with the welding of this elbow joint. This report describes the discrete and continuous phase flow equations. In this regard, to consider the perturbation effects of the energy-perturbation loss model (Realizable k-ε), to model the behavior of particles in the vicinity of the wall and also the scattering of particles due to perturbation in the fluid phase is modeled using random tracing model. . The boundary conditions of solid particles colliding with the wall and the steps of numerical solution of the equations in the discrete phase method are explained and the present effect investigates the erosive corrosion. The results show that even in slow currents with low Reynolds number, the gas-solid fluid is heterogeneous, and increasing the diameter of the solid particles increases the heterogeneity of the gas-solid flow and ultimately causes more abrasion corrosion at the weld roughness. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering of Oil & Gas / Shi You Yu Tian Ran Qi Hua Gong is the property of PetroChina Southwest Oil & Gas Field Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polarization curves and mass losses of SAF3207 hyper-duplex stainless steel under various conditions were measured. The damaged surfaces after erosion–corrosion tests were characterized by scanning electron microscopy. The results showed that an increase in flow velocity could enhance the electrochemical corrosion and consequently decrease the passivation properties of the steel. The erosion–corrosion damage of the samples increased substantially when the flow velocity exceeded the critical value of 4 m·s−1. The mass loss rate increased as the sand content increased, reaching a maximum at 7wt% sand content, corresponding to the most severe electrochemical corrosion damage. When the sand content was increased further, however, the mass loss rate decreased and then tended stable. The mass loss was divided into incubation, sustained, and stationary periods, with a maximum mass loss rate of 12.97 g·h−1·m−2 after an erosion period of 2.5 h. The erosion–corrosion mechanism was investigated in detail. [ABSTRACT FROM AUTHOR]

This paper summarizes the anti-corrosive and anti-erosive properties of water-ethylene glycol based commercial coolant dispersed with nanomaterials. Multiwalled carbon nanotubes (MWCNTs), silver nanoparticles (Ag) and nanosized alumina particles (Al2O3) are dispersed in 0.5% weight in automotive coolants and tested for anti-corrosive properties as per ASTM standards. Prior to dispersion, the nanomaterials are surface modified to get good stability in coolant solutions. The corrosion resistance is measured in terms of weight loss of materials that is commonly used in automotive systems. It is found that oxidized MWCNTs are suitable to automotive systems while silver and Al2O3 nanoparticles are found to be deleterious in nature. [ABSTRACT FROM AUTHOR]

The liquid-solid erosion-corrosion behavior of aluminum in artificial seawater medium at open circuit has been investigated using a submerged jet impingement rig. The aluminum alloy 6061 coupons subjected to erosion corrosion condition were placed normal to the impinging jet. The gap maintained between the nozzle and the specimen was 5mm. In the present study, sea sand was used as an erodent. Erosion corrosion rate was measured using potentiodynamic polarization and electrochemical impedance spectroscopy methods. At a flowrate of 4 lpm passivation was observed in the potentiodynamic polarization plot which was confirmed by the appearance of inductive loop in the Nyquist plot. At higher flowrates no such condition was observed. The system response to impedance studies was characterized by a high frequency capacitive loop and a capacitive loop at the lower frequency. Surface morphology was studied with scanning electron microscopy (semi quantitative analysis) and atomic force microscopy techniques. Elemental mapping was done with electron dispersive X-ray studies. The erosion-corrosion rate increased with increase in the flow rate and temperature. The results of this work will aid in the selection of material for controlled or reduced material loss in sea water circulating equipment' and pipelines. [ABSTRACT FROM AUTHOR]

Erosion or velocity-induced copper pipe corrosion is a significant problem in potable water systems, especially hot water recirculation systems. The little scientific work done in freshwater has not always been able to scientifically isolate the key factors causing these failures; in fact, most existing recommendations rely on anecdotal and/or experiential knowledge from forensic analysis of field failures, which are not confirmed by complementary laboratory research. Consequently, this comprehensive review summarizes prior observations that include mechanical and electrochemical attack induced by water chemistry, temperature, velocity, hydrodynamic conditions, presence of particulate matter, and other variables thought to influence/exacerbate erosion corrosion. Distinct phenomena thought to contribute to erosion corrosion or “flow-induced failure”, including concentration cell corrosion, cavitation, particle/bubble impingement, and high velocity impingement, are explored in detail along with conventional erosion corrosion testing methods. Existing recommendations to prevent erosion corrosion in copper pipes are evaluated and inconsistencies in available guidelines are examined. [ABSTRACT FROM AUTHOR]

Erosion Corrosion is the degradation of material by means of combined effect of mechanical flow and chemical reactions with the surrounding environment. Light weighting of automobiles has been a critical issue in the transportation industries. Magnesium alloy seems to be the best promising next generation's material and as a substitute to aluminium alloy and steel that are being used in automotive, aerospace industries. In this study ,Magnesium,AZ31 and AZ91 were used to investigate the erosion corrosion rate and corrosion rate in 3.5% wt NaCl .The experiments involved the measurement of weight loss .Experimental setup was used to carry out the erosion corrosion test. Immersion test was conducted to determine the corrosion rate. Results include erosion corrosion analysis, comparative analysis of erosion corrosion and corrosion rate. Further SEM analysis was done to study the microstructure behaviour of the samples. It was found that the corrosion rate increases as time of exposure increases. It was also inferred that the erosion corrosion rate is higher than corrosion rate due to moving fluid under the same environmental condition. [ABSTRACT FROM AUTHOR]

Erosion Corrosion is the degradation of material by means of combined effect of mechanical flow and chemical reactions with the surrounding environment. Light weighting of automobiles has been a critical issue in the transportation industries. Magnesium alloy seems to be the best promising next generation's material and as a substitute to aluminium alloy and steel that are being used in automotive, aerospace industries. In this study, Magnesium, AZ31 and AZ91 were used to investigate the erosion corrosion rate and corrosion rate in 3.5% wt NaCl .The experiments involved the measurement of weight loss .Experimental setup was used to carry out the erosion corrosion test. Immersion test was conducted to determine the corrosion rate. Results include erosion corrosion analysis, comparative analysis of erosion corrosion and corrosion rate. Further SEM analysis was done to study the microstructure behaviour of the samples. It was found that the corrosion rate increases as time of exposure increases. It was also inferred that the erosion corrosion rate is higher than corrosion rate due to moving fluid under the same environmental condition. [ABSTRACT FROM AUTHOR]

Corrosion of carbon steel tubes used under boiler water conditions is possibly accelerated by unexpected flow conditions. Mechanisms of flow accelerated corrosion (FAC) are ordinary explained by the dissolution of oxide films formed on carbon steel surfaces, mass transport of metal ions, dissolved oxygen, and water chemicals. These mechanisms have, however, not been precisely proved or reproduced at an experimental level and actual service. In this study, corrosion or erosion-corrosion tests for carbon steel and low alloy steel were conducted in a batch test container at pH 9.0 and 9.2 and temperatures of 393 and 413 K under flow conditions with rotating a gear-type rotor. In order to clarify the corrosion mechanisms, the total corrosion loss of carbon steel was separated as iron mass in oxide films and dissolved iron in the solution. The steel surfaces, debris, and particles suspended in the solutions were observed and analyzed by scanning electron microscopy (SEM, EDX). It was supposed that the partial dissolution of iron from the steel surface and suspended debris occurred followed by the mechanical removal of oxide filmsthat formed on the steel surface, from observations of exposed steel surfaces and cracks on the oxide film surfaces. The dissolution rate of iron depended on the properties of oxide films and the flow conditions. [ABSTRACT FROM AUTHOR]

Highly efficient electric power generation from biomass/waste fuels becomes an important worldwide issue to prevent global warming. In these plants, severe high-temperature corrosion and erosion-corrosion damage occur in boiler tubes influenced by HCl, SOx gases, and chlorides as contaminants in fuels. Coating technologies become important as a countermeasure for such damage, because of the easy maintenance, cost performance, and ease of application on various materials. In severe corrosive conditions of boilers, formation of dense, homogenous, and tough coating layers, as well as protective oxide layers of corrosion-resistant materials, are important. In the last 30 years, materials and coating processes applied in shop and on site have progressed based on many field observations and the consideration of deterioration mechanisms in order to maintain long lifetimes in the plants. Furthermore, new innovative coatings are now being developed by using advanced precise control, nanotechnologies, etc. This paper introduces recent trends of advanced coating developments and applications, such as weld-overlay, cladding, thermal spray coating, and slurry coating for biomass/waste boilers. Furthermore, the evaluation results of deterioration mechanisms and lifetime of coatings, and the future issue for innovative coatings, are presented. [ABSTRACT FROM AUTHOR]

The main aim of this two-part article is to present and arrange the collected important information on widely applicable Ni-based self-fluxing alloy coatings and to point to the variety of investigations considering the period from 2000 to 2013. A survey of the investigations of these coatings obtained by the following deposition technologies will be given: flame spraying, high-velocity oxy-air fuel spraying, detonation gun spraying, electric arc spraying, plasma spraying, plasma-transferred arc welding, and laser cladding. The treated subject is very extensive and is divided into two parts (in the first part wear and corrosion investigations are presented; in the second part the focus is on investigating the impact of external mechanical loading, residual stresses, and the microstructure of coatings). In the first part, following the general facts (terms, deposition technologies, types of investigations, and application), a description and systematization is given of numerous investigations of wear and corrosion as well as cases of the coexistence of wear and corrosion processes. [ABSTRACT FROM AUTHOR]

Incorrect material selection does not always lead to corrosion. In addition to an inferior selection of materials, unsuitable operating conditions and poor design also contributed to the presented failure. A combination of erosion and corrosion caused a leak in an oil cooler of a Navy ship. Because there was no welding seam between the deflectors and tube plate on the carbon steel cooler, cooling water could stream between them, and the flow rate became excessive. This caused erosion on the tube plate. In addition, the repeated change of the cooling liquid after servicing caused a uniform corrosion attack. [ABSTRACT FROM AUTHOR]

Copyright of La Revista Latinoamericana de Metalurgia y Materiales, RLMM is the property of Universidad Simon Bolivar, Departmento de Ciencia de los Materiales and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This article reports a detailed analysis of a failure observed in a petroleum trunkline in the Niger Delta region of southwestern Nigeria. The study was carried out using various techniques including metallurgical, chemical, and x-ray analysis. Leakage was observed along a petroleum trunkline route, and excavation of the trunkline revealed that the trunkline had actually fractured along the 6 o'clock position. The pipeline material was found to conform to the API specification for low carbon steel of X52 grade. Wormwood-like interconnecting pits typical of microbial-induced corrosion were noticed at the 6 o'clock position. Scale deposits composed of corrosion products and debris from the crude oil transported by the trunkline were also noticed. The liquid analysis result showed that the produced water was corrosive, and it has a high bacteria count. The failure of the trunkline was found to be due to the thinning of the pipeline at the 6 o'clock position by the combined effect of abrading by debris, erosion, and corrosion aided by bacteria activities, i.e., microbial-induced corrosion (MIC) and eventual rupture. [ABSTRACT FROM AUTHOR]

In this study, the corrosion behavior of Al 6092/17.5 SiC(p) alloy is investigated. The alloy offers a good resistance to corrosion in 3.5wt% NaCl as shown by weight loss and electrochemical studies conducted in a smoothly stirred condition up to 70°C. The alloy also offered a strong resistance to corrosion in a salt spray chamber. The corrosion behavior of the alloy, however, declined with an increase in velocity, temperature, and addition of polystyrene particles in the electrolyte. The declining corrosion resistance is attributed to the cracking and breakdown of the protective boehmite layer at elevated temperatures, higher velocities, and impact of polystyrene particles. Microanalytical studies reveal the intermetallic precipitates to be the preferred sites for initiation of pits. The alloy offers good service prospects in a marine environment at controlled flow velocities and temperatures. [ABSTRACT FROM AUTHOR]

Erosion corrosion performance of API 5L-X65 carbon steel was investigated at three different impingement velocities (3, 6 & 12 m/s), five different angles (15, 30, 45, 60, & 90°), and with/without solid particles (average particle size of 314 µm). The experiments were conducted in 0.2 M NaCl solution at room temperature for a duration of 24 h and the results showed that the maximum erosion corrosion rate was observed at 45° irrespective of the velocity. The highest erosion corrosion rate at 45° was due to the balance between the shear and normal impact stress at this angle. Ploughing, deep craters, and micro-forging/plastic deformation were found to be the main erosion corrosion mechanisms. The maximum wear scar depth measured using optical profilometery was found to be 51 µm (average) at an impingement angle of 45°. [ABSTRACT FROM AUTHOR]