Corrosion and Protection of Metals

A special issue of Metals (ISSN 2075-4701). This special issue belongs to the section "Corrosion and Protection".

Deadline for manuscript submissions: closed (31 December 2019) | Viewed by 67166

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Special Issue Editor

Special Issue Information

Dear Colleagues,

During the last decades, an enormous effort has been made to understand Corrosion Phenomena and their mechanisms, and to elucidate the causes that dramatically influence the lifetime in service of metal materials. Metal materials performance in aggressive environments is critical for a sustainable society. Materials failure in service impacts the economy, the environment, health, and society. In this regard, corrosion economic losses due to maintenance, repair, and replacement of existing structures and infrastructure account for up to 4% of GDP (gross domestic product) in well developed countries.

One of the biggest issues in corrosion engineering is to estimate the service lifetime. This becomes very difficult, as there is no direct correlation with service lifetime and experimental lab results, usually as result of accelerated testing and real corrosion processes. This issue is of particular concern for society, since existing structures and infrastructure are getting old, and now crucial decisions must be made to replace them.

On the other hand, environmental protocols seek to reduce greenhouse effects. Therefore, low emission policies, in force, establish regulations for the next generation of materials and technologies. Advanced technologies and emergent materials will enable us to get through the next century. Great advances are currently in progress to develop corrosion resistances metal materials for different sectors such as energy, transport, construction, and health.

This Special Issue on Corrosion and Protection of Metals is focused on current trends in corrosion science, engineering, and technology, thus covering subjects related to corrosion mechanism & modelling, protection and inhibition processes, and mitigation strategies. Topics on all aspects of corrosion are invited to contribute to this Special Issue.

Prof. Dr. David M. Bastidas
Guest Editor

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Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Corrosion & protection
  • Inhibition
  • Localized corrosion
  • Environmentally assisted corrosion cracking
  • Crevice corrosion
  • Galvanic corrosion
  • High temperature corrosion
  • Atmospheric corrosion
  • Corrosion of steel in concrete
  • Modelling & simulation

Published Papers (16 papers)

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Editorial

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5 pages, 194 KiB  
Editorial
Corrosion and Protection of Metals
by David M. Bastidas
Metals 2020, 10(4), 458; https://doi.org/10.3390/met10040458 - 01 Apr 2020
Cited by 12 | Viewed by 3848
Abstract
During the last few decades, an enormous effort has been made to understand corrosion phenomena and their mechanisms, and to elucidate the causes that dramatically influence the service lifetime of metal materials [...] Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)

Research

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15 pages, 6460 KiB  
Article
Evaluation of the DOS by DL−EPR of UNSM Processed Inconel 718
by Ulises Martin, Jacob Ress, Juan Bosch and David M. Bastidas
Metals 2020, 10(2), 204; https://doi.org/10.3390/met10020204 - 01 Feb 2020
Cited by 10 | Viewed by 3157
Abstract
In this work, influence of ultrasonic nanocrystal surface modification (UNSM) on the degree of sensitization (DOS) in Inconel 718 has been studied and correlated with the resulting microstructure. The UNSM processed samples decreased their grain size from 11.9 µm to 7.75 µm, increasing [...] Read more.
In this work, influence of ultrasonic nanocrystal surface modification (UNSM) on the degree of sensitization (DOS) in Inconel 718 has been studied and correlated with the resulting microstructure. The UNSM processed samples decreased their grain size from 11.9 µm to 7.75 µm, increasing the surface of grain boundaries, and thus enhancing the area where δ phase and niobium carbides precipitate. The effect of the UNSM process on the DOS of Inconel 718 was studied by the double loop electrochemical potentiokinetic reactivation (DL−EPR) test. The DL−EPR showed that for UNSM processed samples with no thermal treatment, the DOS increased up to 59.6%, while for UNSM treated samples that were post-annealed at 1000 °C for 10 min and water quenched the DOS decreased down to 40.9%. The increase of grain boundaries surface area and triple junctions after the UNSM process enables the formation of twice the amount of δ phase compared to the as-received Inconel 718 bulk sample. The area fraction of the grain boundary covered by δ phase was of 9.87% in the UNSM region while in the bulk the area fraction was 4.09%. In summary, it was found that after UNSM process, the annealing at 1000 °C for 10 min and water quenching promoted the transformation of γ″ to form δ phase on the grain boundaries, which reduces the intergranular corrosion susceptibility. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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12 pages, 1125 KiB  
Article
The Influence of Test-Panel Orientation and Exposure Angle on the Corrosion Rate of Carbon Steel. Mathematical Modelling
by Juan J. Santana, Víctor Cano, Helena C. Vasconcelos and Ricardo M. Souto
Metals 2020, 10(2), 196; https://doi.org/10.3390/met10020196 - 29 Jan 2020
Cited by 8 | Viewed by 2330
Abstract
The effects of both test-panel orientation and exposure angle on the atmospheric corrosion rates of carbon steel probes exposed to a marine atmosphere were investigated. Test samples were exposed in a tree-shape metallic frame with either three exposure angles of 30°, 45° and [...] Read more.
The effects of both test-panel orientation and exposure angle on the atmospheric corrosion rates of carbon steel probes exposed to a marine atmosphere were investigated. Test samples were exposed in a tree-shape metallic frame with either three exposure angles of 30°, 45° and 60° and orientation north-northeast (N-NE), or eight different orientation angles around a circumference. It was found that the experimental corrosion rates of carbon steel decreased for the specimens exposed with greater exposure angles, whereas the highest corrosion rates were found for those oriented to N-NE due to the influence of the prevailing winds. The obtained data obtained were fitted using the bi-logarithmic law and its variations as to take in account the amounts of pollutants and the time of wetness (TOW) for each particular case with somewhat good agreement, although these models failed when all the effects were considered simultaneously. In this work, we propose a new mathematical model including qualitative variables to account for the effects of both exposure and orientation angles while producing the highest quality fits. The goodness of the fit was used to determine the performance of the mathematical models. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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16 pages, 4552 KiB  
Article
Corrosion Study of Pipeline Steel under Stress at Different Cathodic Potentials by EIS
by Ricardo Galván-Martínez, Ricardo Orozco-Cruz, Andrés Carmona-Hernández, Edgar Mejía-Sánchez, Miguel A. Morales-Cabrera and Antonio Contreras
Metals 2019, 9(12), 1353; https://doi.org/10.3390/met9121353 - 16 Dec 2019
Cited by 14 | Viewed by 3311
Abstract
The effect of different cathodic potentials applied to the X70 pipeline steel immersed in acidified and aerated synthetic soil solution under stress using a slow strain rate test (SSRT) and electrochemical impedance spectroscopy (EIS) was studied. According to SSRT results and the fracture [...] Read more.
The effect of different cathodic potentials applied to the X70 pipeline steel immersed in acidified and aerated synthetic soil solution under stress using a slow strain rate test (SSRT) and electrochemical impedance spectroscopy (EIS) was studied. According to SSRT results and the fracture surface analysis by scanning electron microscopy (SEM), the steel susceptibility to stress corrosion cracking (SCC) increased as the cathodic polarization increased (Ecp). This behavior is attributed to the anodic dissolution at the tip of the crack and the increment of the cathodic reaction (hydrogen evolution) producing hydrogen embrittlement. Nevertheless, when the Ecp was subjected to the maximum cathodic potential applied (−970 mV), the susceptibility decreased; this behavior is attributed to the fact that the anodic dissolution was suppressed and the process of the SCC was dominated only by hydrogen embrittlement (HE). The EIS results showed that the cathodic process was influenced by the mass transport (hydrogen diffusion) due to the steel undergoing so many changes in the metallic surface as a result of the applied strain that it generated active sites at the surface. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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14 pages, 6056 KiB  
Article
Shortcomings of International Standard ISO 9223 for the Classification, Determination, and Estimation of Atmosphere Corrosivities in Subtropical Archipelagic Conditions—The Case of the Canary Islands (Spain)
by Juan J. Santana, Alejandro Ramos, Alejandro Rodriguez-Gonzalez, Helena C. Vasconcelos, Vicente Mena, Bibiana M. Fernández-Pérez and Ricardo M. Souto
Metals 2019, 9(10), 1105; https://doi.org/10.3390/met9101105 - 15 Oct 2019
Cited by 7 | Viewed by 3531
Abstract
The classification, assessment, and estimation of the atmospheric corrosivity are fixed by the ISO 9223 standard. Its recent second edition introduced a new corrosivity category for extreme environments CX, and defined mathematical models that contain dose–response functions for normative corrosivity estimations. It is [...] Read more.
The classification, assessment, and estimation of the atmospheric corrosivity are fixed by the ISO 9223 standard. Its recent second edition introduced a new corrosivity category for extreme environments CX, and defined mathematical models that contain dose–response functions for normative corrosivity estimations. It is shown here that application of the ISO 9223 standard to archipelagic subtropical areas exhibits major shortcomings. Firstly, the corrosion rates of zinc and copper exceed the range employed to define the CX category. Secondly, normative corrosivity estimation would require the mathematical models to be redefined introducing the time of wetness and a new set of operation constants. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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19 pages, 6574 KiB  
Article
Influence of the Alkaline Reserve of Chloride-Contaminated Mortars on the 6-Year Corrosion Behavior of Corrugated UNS S32304 and S32001 Stainless Steels
by Asunción Bautista, Francisco Velasco and Manuel Torres-Carrasco
Metals 2019, 9(6), 686; https://doi.org/10.3390/met9060686 - 14 Jun 2019
Cited by 10 | Viewed by 2684
Abstract
The durability of two lean corrugated duplex stainless steel (UNS S32304 and S32001) bars manufactured for concrete reinforcement was studied in four different corrosive conditions. These duplex stainless steels are more economical than the most traditional, well-known duplex grade steels (UNS S32205). The [...] Read more.
The durability of two lean corrugated duplex stainless steel (UNS S32304 and S32001) bars manufactured for concrete reinforcement was studied in four different corrosive conditions. These duplex stainless steels are more economical than the most traditional, well-known duplex grade steels (UNS S32205). The research was carried out in mortar samples for six years. In half of the samples, the alkaline reserve had been previously decreased, and their pH was slightly below 12, while in the other half, the pH close to the bars remained as-manufactured. Moreover, there were samples with modified and non-modified alkaline reserve where chlorides had been previously added to the mortar which were exposed to high relative humidity. In other samples—which were partially immersed in 3.5% NaCl—the chlorides entered through the mortar by natural diffusion. The electrochemical behavior of the reinforcements in these conditions was periodically monitored through corrosion potential (Ecorr) and electrochemical impedance spectroscopy (EIS) measurements during the whole testing period. The samples were anodically polarized at the end of the exposure. The results prove that the decrease in the alkaline reserve of the mortars can affect the corrosion behavior of the studied lean duplex in environments with high chloride concentrations. The duplex microstructure of the reinforcements makes it so that the corrosion proceeds by selective attack of the phases. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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19 pages, 10002 KiB  
Article
Corrosion Behavior of Different Brass Alloys for Drinking Water Distribution Systems
by Jamal Choucri, Federica Zanotto, Vincenzo Grassi, Andrea Balbo, Mohamed Ebn Touhami, Ilyass Mansouri and Cecilia Monticelli
Metals 2019, 9(6), 649; https://doi.org/10.3390/met9060649 - 04 Jun 2019
Cited by 27 | Viewed by 8104
Abstract
Some α + β’ brass components of drinking water distribution systems in Morocco underwent early failures and were investigated to assess the nature and extent of the corrosion attacks. They exhibited different corrosion forms, often accompanied by extensive β’ dezincification. In order to [...] Read more.
Some α + β’ brass components of drinking water distribution systems in Morocco underwent early failures and were investigated to assess the nature and extent of the corrosion attacks. They exhibited different corrosion forms, often accompanied by extensive β’ dezincification. In order to offer viable alternatives to these traditional low cost materials, the corrosion behavior of two representative α + β’ brass components was compared to that of brass alloys with nominal compositions CuZn36Pb2As and CuZn21Si3P, marketed as dezincification resistant. CuZn21Si3P is a recently developed eco-friendly brass produced without any arsenic or lead. Electrochemical tests in simulated drinking water showed that after 10 days of immersion CuZn21Si3P exhibited the highest polarization resistance (Rp) values but after longer immersion periods its Rp values became comparable or lower than those of the other alloys. After 150 days, scanning electron microscope coupled to energy dispersive spectroscopy (SEM-EDS) analyses evidenced that the highest dezincification resistance was afforded by CuZn36Pb2As (longitudinal section of extruded bar), exhibiting dealloying and subsequent oxidation of β’ only at a small depth. Limited surface dealloying was also found on CuZn21Si3P, which underwent selective silicon and zinc dissolution and negligible inner oxidation of both α and κ constituent phases, likely due to peculiar galvanic effects. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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11 pages, 5069 KiB  
Article
Atmospheric Corrosion Sensor Based on Strain Measurement with an Active Dummy Circuit Method in Experiment with Corrosion Products
by Nining Purwasih, Naoya Kasai, Shinji Okazaki, Hiroshi Kihira and Yukihisa Kuriyama
Metals 2019, 9(5), 579; https://doi.org/10.3390/met9050579 - 18 May 2019
Cited by 8 | Viewed by 3159
Abstract
This study analyzed an atmospheric corrosion sensor using strain measurements (ACSSM) with an active dummy method for corrosion product experiments. An initial compensation thermal strain experiment was performed with elapsed time. Further analyses used dry-wet environments with salt water spray to investigate the [...] Read more.
This study analyzed an atmospheric corrosion sensor using strain measurements (ACSSM) with an active dummy method for corrosion product experiments. An initial compensation thermal strain experiment was performed with elapsed time. Further analyses used dry-wet environments with salt water spray to investigate the thickness reduction performance of the corrosion product on low-carbon steel samples. The ACSSM with an active dummy method accurately measured signals induced by the specimen thickness reduction, despite the noise in the signal. Moreover, the effects of corrosion products on the signal were discussed. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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10 pages, 1149 KiB  
Article
Electrochemical Corrosion Behavior of Fe3Al/TiC and Fe3Al-Cr/TiC Coatings Prepared by HVOF in NaCl Solution
by Najmeh Ahledel, Robert Schulz, Mario Gariepy, Hendra Hermawan and Houshang Alamdari
Metals 2019, 9(4), 437; https://doi.org/10.3390/met9040437 - 13 Apr 2019
Cited by 12 | Viewed by 3088
Abstract
Adding TiC particles into iron aluminide coatings has been found to improve its wear resistance, but its corrosion behavior is less known. In this study, the corrosion behavior of Fe3Al/TiC and Fe3Al-Cr/TiC composite coatings, prepared by high velocity oxy [...] Read more.
Adding TiC particles into iron aluminide coatings has been found to improve its wear resistance, but its corrosion behavior is less known. In this study, the corrosion behavior of Fe3Al/TiC and Fe3Al-Cr/TiC composite coatings, prepared by high velocity oxy fuel (HVOF) spraying, was studied in 3.5 wt. % NaCl solution by means of electrochemical techniques and surface analysis. Results revealed that adding TiC particles into Fe3Al matrix to improve the wear resistance does not deteriorate the corrosion behavior of Fe3Al coating. It was also showed that addition of chromium to Fe3Al/TiC composite provides a more protective layer. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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15 pages, 2663 KiB  
Article
Simulation Approach for Cathodic Protection Prediction of Aluminum Fin-Tube Heat Exchanger Using Boundary Element Method
by Yong-Sang Kim, In-Jun Park and Jung-Gu Kim
Metals 2019, 9(3), 376; https://doi.org/10.3390/met9030376 - 23 Mar 2019
Cited by 8 | Viewed by 3641
Abstract
The multi-galvanic effect of an Al fin-tube heat exchanger was evaluated using polarization tests, numerical simulation, and the seawater acetic acid test (SWAAT). Determination of the polarization state using polarization curves was well correlated with numerical simulations using a high-conductivity electrolyte. However, the [...] Read more.
The multi-galvanic effect of an Al fin-tube heat exchanger was evaluated using polarization tests, numerical simulation, and the seawater acetic acid test (SWAAT). Determination of the polarization state using polarization curves was well correlated with numerical simulations using a high-conductivity electrolyte. However, the polarization results did not match those of the low-conductivity electrolyte due to the lower galvanic effect. Although the polarization state is changed by electrolyte conductivity, the total net current of the tube is decreased in the case of the anodic joint. From SWAAT results, the leakage time of Al fin-tube heat exchanger assembled by anodic joint was longer than the case with cathodic joint. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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18 pages, 5167 KiB  
Article
Resistance of Thermally Aged DSS 2304 against Localized Corrosion Attack
by Federica Zanotto, Vincenzo Grassi, Andrea Balbo, Cecilia Monticelli and Fabrizio Zucchi
Metals 2018, 8(12), 1022; https://doi.org/10.3390/met8121022 - 05 Dec 2018
Cited by 5 | Viewed by 2648
Abstract
In this paper, the effects of thermal aging in the 650–850 °C range on the localized corrosion behaviour of duplex stainless steel (DSS) 2304 was investigated. Pitting corrosion resistance was assessed by pitting potential (Epitt) and critical pitting temperature (CPT) determination, [...] Read more.
In this paper, the effects of thermal aging in the 650–850 °C range on the localized corrosion behaviour of duplex stainless steel (DSS) 2304 was investigated. Pitting corrosion resistance was assessed by pitting potential (Epitt) and critical pitting temperature (CPT) determination, while the degree of sensitisation (DOS) to intergranular corrosion (IGC) was evaluated by double loop electrochemical potentiokinetic reactivation (DL-EPR). The susceptibility to stress corrosion cracking (SCC), evaluated in standard NACE TM-0177 solution at pH 2.7 and 25 °C, with the addition of S2O32− at 10−3 M, resulted in general good agreement with pitting and IGC behaviour. In fact, as-received DSS 2304 aged for 5 min at 650 °C or 750 °C presented a high resistance to localized corrosion. The alloy corrosion behaviour was severely impaired with an aging time of 60 min at 650 °C and of 10 or 60 min at 750 °C, due to the precipitation of finely distributed M23C6-type chromium carbides at ferrite/austenite interphases, which determined the formation of chromium and molybdenum depleted areas. The behaviour of samples aged at 850 °C also depended on the aging time, but, at 60 min, the rediffusion of passivating elements produced a recovery of the alloy resistance to pitting, IGC and SCC. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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16 pages, 4229 KiB  
Article
Initial Stages of AZ31B Magnesium Alloy Degradation in Ringer’s Solution: Interpretation of EIS, Mass Loss, Hydrogen Evolution Data and Scanning Electron Microscopy Observations
by Lucien Veleva, Mareny Guadalupe Fernández-Olaya and Sebastián Feliu, Jr.
Metals 2018, 8(11), 933; https://doi.org/10.3390/met8110933 - 12 Nov 2018
Cited by 15 | Viewed by 4887
Abstract
The initial stages of corrosion of AZ31B magnesium alloy, immersed in Ringer’s solution at 37 °C body temperature for four days, have been evaluated by independent gravimetric and chemical methods and through electrochemical impedance spectroscopy (EIS) measurements. The corrosion current densities estimated by [...] Read more.
The initial stages of corrosion of AZ31B magnesium alloy, immersed in Ringer’s solution at 37 °C body temperature for four days, have been evaluated by independent gravimetric and chemical methods and through electrochemical impedance spectroscopy (EIS) measurements. The corrosion current densities estimated by hydrogen evolution are in good agreement with the time-integrated reciprocal charge transfer resistance values estimated by EIS. The change in the inductive behavior has been correlated with difference in the chemical composition of corrosion layers. At the shorter immersion of 2 days, EDS analysis of cross section of the uniform corrosion layer detected Cl and Al elements, perhaps as formed aluminum oxychlorides salts. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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12 pages, 4752 KiB  
Article
Passivity of Spring Steels with Compressive Residual Stress
by Kyu-Hyuk Lee, Seung-Ho Ahn, Ji-Won Seo and HeeJin Jang
Metals 2018, 8(10), 788; https://doi.org/10.3390/met8100788 - 02 Oct 2018
Cited by 2 | Viewed by 3024
Abstract
The electrochemical corrosion behavior and the semiconducting properties of the passive film formed on a coil spring steel were investigated in a buffer solution at pH 9. The anodic dissolution was mitigated, and the passive film grew faster for the spring steel with [...] Read more.
The electrochemical corrosion behavior and the semiconducting properties of the passive film formed on a coil spring steel were investigated in a buffer solution at pH 9. The anodic dissolution was mitigated, and the passive film grew faster for the spring steel with compressive residual stress than the one without stress. The passive films had an n-type semiconducting property with a high density of oxygen vacancy, and the defect density was lower for the specimens with compressive stress. The passive current density of the specimens with stress was higher and showed fluctuation. These characteristics imply that the growth mechanism of passive film and the transport of vacancies in the film on metals and alloys depend on the residual stress on the metallic surface. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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11 pages, 6321 KiB  
Article
Effect of Surface Nanocrystallization on Corrosion Resistance of the Conformed Cu-0.4%Mg Alloy in NaCl Solution
by Dan Song, Jinghua Jiang, Xiaonan Guan, Yanxin Qiao, Xuebin Li, Jianqing Chen, Jiapeng Sun and Aibin Ma
Metals 2018, 8(10), 765; https://doi.org/10.3390/met8100765 - 26 Sep 2018
Cited by 6 | Viewed by 2727
Abstract
Surface nano-crystallization (SNC) of a conform-extruded Cu-0.4 wt.% Mg alloy was successfully conducted by high-speed rotating wire-brushing to obtain the deformed zone with dislocation cells and nanocrystallines. SNC promotes the anodic dissolution and corrosion rate of the Cu-Mg alloy in the initial stage [...] Read more.
Surface nano-crystallization (SNC) of a conform-extruded Cu-0.4 wt.% Mg alloy was successfully conducted by high-speed rotating wire-brushing to obtain the deformed zone with dislocation cells and nanocrystallines. SNC promotes the anodic dissolution and corrosion rate of the Cu-Mg alloy in the initial stage of immersion corrosion in 0.1 M NaCl solution. The weakened corrosion resistance is mainly attributed to the higher corrosion activity of SNC-treated alloy. With extending the immersion time, the SNC-treated alloy slows the corrosion rate dramatically and exhibits uniform dissolution of the surface. The formation of the dense corrosion products leads to the improvement of overall corrosion performance. It indicates that the SNC-treated Cu-Mg alloy can function reliably for a longer duration in a corrosive environment. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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13 pages, 4296 KiB  
Article
Molybdenum Effects on Pitting Corrosion Resistance of FeCrMnMoNC Austenitic Stainless Steels
by Heon-Young Ha, Tae-Ho Lee, Jee-Hwan Bae and Dong Won Chun
Metals 2018, 8(8), 653; https://doi.org/10.3390/met8080653 - 20 Aug 2018
Cited by 73 | Viewed by 7738
Abstract
For Fe-based 18Cr10Mn0.4N0.5C(0–2.17)Mo (in wt %) austenitic stainless steels, effects of Mo on pitting corrosion resistance and the improvement mechanism were investigated. Alloying Mo increased pitting and repassivation potentials and enhanced the passive film resistance by decreasing number of point defects in the [...] Read more.
For Fe-based 18Cr10Mn0.4N0.5C(0–2.17)Mo (in wt %) austenitic stainless steels, effects of Mo on pitting corrosion resistance and the improvement mechanism were investigated. Alloying Mo increased pitting and repassivation potentials and enhanced the passive film resistance by decreasing number of point defects in the film. In addition, Mo reduced critical dissolution rate of the alloys in acidified chloride solutions, and the alloy with higher Mo content could remain in the passive state in stronger acid. Thus, it was concluded that the alloying Mo enhanced pitting corrosion resistance of the alloys through increasing protectiveness of passive film and lowering pit growth rate. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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Review

Jump to: Editorial, Research

18 pages, 5877 KiB  
Review
Effects of Different Parameters on Initiation and Propagation of Stress Corrosion Cracks in Pipeline Steels: A Review
by M.A. Mohtadi-Bonab
Metals 2019, 9(5), 590; https://doi.org/10.3390/met9050590 - 22 May 2019
Cited by 55 | Viewed by 7719
Abstract
The demand for pipeline steels has increased in the last several decades since they were able to provide an immune and economical way to carry oil and natural gas over long distances. There are two important damage modes in pipeline steels including stress [...] Read more.
The demand for pipeline steels has increased in the last several decades since they were able to provide an immune and economical way to carry oil and natural gas over long distances. There are two important damage modes in pipeline steels including stress corrosion cracking (SCC) and hydrogen induced cracking (HIC). The SCC cracks are those cracks which are induced due to the combined effects of a corrosive environment and sustained tensile stress. The present review article is an attempt to highlight important factors affecting the SCC in pipeline steels. Based on a literature survey, it is concluded that many factors, such as microstructure of steel, residual stresses, chemical composition of steel, applied load, alternating current (AC) current and texture, and grain boundary character affect the SCC crack initiation and propagation in pipeline steels. It is also found that crystallographic texture plays a key role in crack propagation. Grain boundaries associated with {111}∥rolling plane, {110}∥rolling plane, coincidence site lattice boundaries and low angle grain boundaries are recognized as crack resistant paths while grains with high angle grain boundaries provide easy path for the SCC intergranular crack propagation. Finally, the SCC resistance in pipeline steels is improved by modifying the microstructure of steel or controlling the texture and grain boundary character. Full article
(This article belongs to the Special Issue Corrosion and Protection of Metals)
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