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11 pages, 1811 KiB

Open AccessArticle

Quantification of Hydrogen Flux from Atmospheric Corrosion of Steel Using the Scanning Kelvin Probe Technique

by Flavien Vucko, Varvara Shubina Helbert and Andrei Nazarov

Metals 2023, 13(8), 1427; https://doi.org/10.3390/met13081427 - 9 Aug 2023

Cited by 1 | Viewed by 1034

Abstract

The atmospheric corrosion of high-strength steels can lead to hydrogen absorption directly linked to hydrogen embrittlement or delayed fracture phenomena. A scanning Kelvin probe (SKP) and electrochemical permeation technique (EPT) were applied to correlate the potential of an oxidized surface with the flux [...] Read more.

The atmospheric corrosion of high-strength steels can lead to hydrogen absorption directly linked to hydrogen embrittlement or delayed fracture phenomena. A scanning Kelvin probe (SKP) and electrochemical permeation technique (EPT) were applied to correlate the potential of an oxidized surface with the flux of hydrogen across a thin steel membrane. The side of the membrane opposite the corroding or electrochemically charged area was analyzed. The potential drop in the oxide was calibrated in terms of surface hydrogen activity, and SKP can be applied in situ for the mapping of hydrogen distribution in the corroding metal. A very low flux of hydrogen can be characterized and quantified by SKP, which is typically observed under atmospheric corrosion conditions. Therefore, hydrogen localization that drives steel durability under atmospheric corrosion conditions can be evaluated. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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23 pages, 10812 KiB

Open AccessArticle

Erosion–Corrosion Behavior of 90/10 and 70/30 Copper–Nickel Tubes in 1 wt% NaCl Solution

by Lei Wu, Aili Ma, Lianmin Zhang, Guangming Li, Lingyue Hu, Zhengbin Wang and Yugui Zheng

Metals 2023, 13(2), 401; https://doi.org/10.3390/met13020401 - 15 Feb 2023

Cited by 11 | Viewed by 2239

Abstract

The erosion–corrosion behavior of 90/10 and 70/30 copper–nickel tubes was investigated by in situ electrochemical tests on a self-built loop apparatus and ex situ surface characterization. The corrosion product film that formed at 1.5 m/s for the 90/10 tube and at 0.5 m/s [...] Read more.

The erosion–corrosion behavior of 90/10 and 70/30 copper–nickel tubes was investigated by in situ electrochemical tests on a self-built loop apparatus and ex situ surface characterization. The corrosion product film that formed at 1.5 m/s for the 90/10 tube and at 0.5 m/s for the 70/30 tube showed the best corrosion resistance. For the 90/10 tube, a continuous film existed below 3 m/s and mainly inhibited a cathodic reaction. For the 70/30 tube, a continuous film existed in the range of 0.5–4.7 m/s and was more similar to typical passive film electrochemically, although it was cracked at 4–4.7 m/s. So, the “critical flow velocity” of the 90/10 tube was between 3 m/s and 4 m/s, and that of the 70/30 tube was beyond 4.7 m/s. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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17 pages, 52220 KiB

Open AccessArticle

Study on the Effects of Fluid Parameters on Erosion-Enhanced Corrosion of 90/10 Copper–Nickel Alloy Using Wire Beam Electrode

by Zehua Wang, Zhengbin Wang, Hongxiang Hu, Chunhua Zhang, Song Zhang and Yugui Zheng

Metals 2023, 13(2), 380; https://doi.org/10.3390/met13020380 - 13 Feb 2023

Cited by 4 | Viewed by 1557

Abstract

This paper clarifies the effects of the fluid parameters of flow velocity, impact angle and sand impact frequency on the erosion-enhanced corrosion of 90/10 copper–nickel alloy by combining computational fluid dynamics (CFD) simulation, wire beam electrode (WBE) technology and electrochemical measurements. The results [...] Read more.

This paper clarifies the effects of the fluid parameters of flow velocity, impact angle and sand impact frequency on the erosion-enhanced corrosion of 90/10 copper–nickel alloy by combining computational fluid dynamics (CFD) simulation, wire beam electrode (WBE) technology and electrochemical measurements. The results show that under the conditions without sand particles, erosion-enhanced corrosion is dominated by the impact angle and the flow velocity at lower (<0.860 m/s) and higher (2.370~5.644 m/s) flow velocities, respectively, while both the two fluid parameters have noticeable effects on erosion-enhanced corrosion at intermediate flow velocities (0.860~2.370 m/s). In contrast, adding sand particles corresponding to the sand impact frequency can further increase the corrosion current density without changing the effects of the flow velocity and impact angle. It demonstrates that all three fluid parameters show great effects on the erosion-enhanced corrosion of 90/10 copper–nickel alloy under conditions with sand particles. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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9 pages, 2180 KiB

Open AccessCommunication

Corrosion Performances of Selective Laser Melting Ti6Al4V Alloy in Different Solutions

by Xuedan Chen, Qilong Liao, Min Gong and Qingshan Fu

Metals 2023, 13(2), 192; https://doi.org/10.3390/met13020192 - 18 Jan 2023

Cited by 7 | Viewed by 1945

Abstract

Selective laser melting (SLM) can fabricate titanium and its alloy components with both elaborate internal architectures and complex shapes without geometric constrictions. The corrosion resistance of SLM-produced Ti and its alloy is crucial in some applications such as marine and biomedical environments. Here, [...] Read more.

Selective laser melting (SLM) can fabricate titanium and its alloy components with both elaborate internal architectures and complex shapes without geometric constrictions. The corrosion resistance of SLM-produced Ti and its alloy is crucial in some applications such as marine and biomedical environments. Here, potentiodynamic polarization and electrochemical impedance spectroscopy were used to evaluate the corrosion behaviors of SLM-produced Ti-6Al-4V in the four corrosive media (simulated body fluid (SBF), phosphate buffered saline solutions (PBS), 3.5 wt.% NaCl aqueous solution, 15 wt.% NaCl aqueous solution). The relevant results demonstrate the inferior corrosion resistance of the SLM-produced Ti-6Al-4V sheet compared with the commercial casting Ti-6Al-4V sheet in the four solutions. The corrosive current density of SLM-produced Ti-6Al-4V in PBS solution is 1.78 μA cm⁻² and 7.065 μA cm⁻² in 15 wt.% NaCl solution, and the values of charge transfer resistance for SLM-produced Ti-6Al-4V in the four solutions are in the order: 17.9 kΩ cm⁻² (in 15 wt.% NaCl) < 25.2 kΩ cm⁻² (in 3.5 wt.% NaCl) < 28.1 kΩ cm⁻² (in SBF) < 39.8 kΩ cm⁻² (in PBS), demonstrating the best protective performance of the passivation film on the SLM-produced Ti-6Al-4V sheet in PBS. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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14 pages, 10556 KiB

Open AccessArticle

Effect of Toughness and Ductility on the Cavitation Erosion of Martensitic Stainless Steel

by Lianqing Zhao, Hongxiang Hu and Xuming Guo

Metals 2023, 13(1), 154; https://doi.org/10.3390/met13010154 - 12 Jan 2023

Cited by 4 | Viewed by 1812

Abstract

Martensitic stainless steel containing 13% Cr–4% Ni suffers cavitation erosion (CE) as the common material of hydro turbine impellers. Two 13% Cr–4% Ni stainless steel samples were obtained by different melting and heating processes. One was of relatively low toughness but high ductility [...] Read more.

Martensitic stainless steel containing 13% Cr–4% Ni suffers cavitation erosion (CE) as the common material of hydro turbine impellers. Two 13% Cr–4% Ni stainless steel samples were obtained by different melting and heating processes. One was of relatively low toughness but high ductility (LTHD), and the other was of relatively high toughness but low ductility (HTLD). This paper is to clarify the relationship between the mechanical properties and the CE resistance of the experimental steel samples. The CE of the two materials was studied using an ultrasonic vibration cavitation erosion rig. Mass loss, morphological observation, nanoindentation characterization, and tensile tests were employed to clarify the erosion mechanism. The results showed that LTHD stainless steel had slightly higher ductility, but lower toughness than HTLD material. The mass loss method verified that the CE resistance of LTHD material was higher than that for the HTLD material. In addition, both materials had an incubation stage of 2 h in the distilled water. The SEM revealed that material removal was preferentially initiated from the grain boundaries and slip zone after the incubation period. The ductility could delay the fracture of the material, which contributed more to cavitation erosion resistance than the toughness of the materials. The hardness test showed few relationships with the CE resistance. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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8 pages, 1915 KiB

Open AccessArticle

Application of Machine Learning for Data with an Atmospheric Corrosion Monitoring Sensor Based on Strain Measurements

by Taisei Okura, Naoya Kasai, Hirotsugu Minowa and Shinji Okazaki

Metals 2022, 12(7), 1179; https://doi.org/10.3390/met12071179 - 11 Jul 2022

Cited by 4 | Viewed by 1972

Abstract

Machine learning methods were applied to data with an atmospheric corrosion monitoring sensor based on strain measurements to improve the evaluation accuracy of the thickness reduction of a low-carbon steel plate due to atmospheric corrosion. Monitoring data used in this study were taken [...] Read more.

Machine learning methods were applied to data with an atmospheric corrosion monitoring sensor based on strain measurements to improve the evaluation accuracy of the thickness reduction of a low-carbon steel plate due to atmospheric corrosion. Monitoring data used in this study were taken in a previous study using active–dummy strain gauges for corrosion product experiments. Values measured by the gauges before inducing corrosion via saltwater treatment of the test piece and reference data of the thickness reduction in a reference test piece were used for training data. By using the trained machine learning methods, the errors for the outputs of the machine learning models were smaller than those for the evaluation in monitoring data of our previous study. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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17 pages, 13344 KiB

Open AccessArticle

Comparison of the Three-Phase Corrosion Behavior of SiN and 304L Stainless Steels in 6 M Nitric Acid Solution at Different Temperatures

by Shengxuan Sun, Lianmin Zhang, Aili Ma, Enobong Felix Daniel, Chunzhi Zhang and Yugui Zheng

Metals 2022, 12(6), 922; https://doi.org/10.3390/met12060922 - 27 May 2022

Cited by 5 | Viewed by 2432

Abstract

In this work, the three-phase corrosion behavior of SiN and 304L stainless steels was comparatively investigated in a 6 M nitric acid solution at different temperatures. It was found that the corrosion rates of both steels in the liquid phase, vapor phase and [...] Read more.

In this work, the three-phase corrosion behavior of SiN and 304L stainless steels was comparatively investigated in a 6 M nitric acid solution at different temperatures. It was found that the corrosion rates of both steels in the liquid phase, vapor phase and condensate phase of nitric acid showed an increasing trend with rising temperature. Meanwhile, there also existed some differences in the corrosion kinetics and the corrosion resistance in the different phases of nitric acid. The corrosion rate of SiN and 304L stainless steels in the liquid phase of nitric acid had a cubic function relationship with temperature, and SiN stainless steel presented better corrosion resistance without intergranular corrosion (IGC) compared with 304L stainless steel with IGC at 100 °C and 120 °C. By contrast, the SiN stainless steel displayed a lower corrosion resistance than 304L stainless steel in the vapor phase of nitric acid at the same temperature, and the corrosion rates of SiN and 304L stainless steels showed a quadratic function relationship with temperature, indicating a milder corrosion in the vapor phase in comparison with that in the liquid phase of nitric acid. In the condensate phase of nitric acid, there was a similar corrosion behavior of the two steels to that in the nitric acid vapor phase, and 304L stainless steel also demonstrated a better corrosion resistance than SiN stainless steel at the same temperature. The differences in corrosion behavior between the two steels could be attributed to the changed media environment and the different alloy composition, and the two aspects were discussed in detail based on relevant experimental results. This work can provide an important insight into the material selection for reprocessing equipment and the development of new corrosion-resistant materials used in spent fuel reprocessing. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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13 pages, 4587 KiB

Open AccessArticle

Microstructure and Corrosion Resistance of Fusion Welding Zone for Duplextubes Welded with Q345R Tube Sheet under Different Welding Currents

by Guofu Ou, Guangwei Qian, Haozhe Jin, Wangping Wu and Qianqian Li

Metals 2022, 12(5), 705; https://doi.org/10.3390/met12050705 - 20 Apr 2022

Cited by 2 | Viewed by 2183

Abstract

Duplextubes are widely used in oil and gas storage and transportation, the nuclear industry, and other fields, but the welding quality of metals is an important factor affecting the use of equipment. In order to study the welding quality of S10C steel/Incoloy 825 [...] Read more.

Duplextubes are widely used in oil and gas storage and transportation, the nuclear industry, and other fields, but the welding quality of metals is an important factor affecting the use of equipment. In order to study the welding quality of S10C steel/Incoloy 825 duplextubes and Q345R tube sheet based on gas tungsten arc welding technology with a filler of ER50-6 carbon steel welding wire, the microstructure and grain size of fusion welding zone of duplextubes and tube sheet under welding currents of 150 A, 160 A, and 170 A were studied by optical microscopy and scanning electron microscopy. At the same time, the corrosion behavior of fusion welding zone after the welding was investigated in 3.5 wt.% NaCl solution by potentiodynamic polarization and electrochemical impedance spectroscopy. The results show that the metallurgical structure of the fusion welding zone was mainly composed of δ-ferrite and retained austenite. The grain size in the fusion welding zone increased with the increase of the welding current. The corrosion resistance of the fusion welding zone welded with a high welding current of 170 A was better than that with low welding currents. However, the pitting corrosion resistance of fusion welding zone with the lowest welding current of 150 A was better than that with high welding currents. This study can provide a preliminary exploration for the manufacture and applicability of duplextubes air coolers. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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13 pages, 4335 KiB

Open AccessArticle

Study on the Microstructure and Mechanical Properties of a Ti/Mg Alloy Clad Plate Produced by Explosive Welding

by Hui Zhao, Chaochao Zhao, Yang Yang, Yizhuo Wang, Liyuan Sheng, Yixu Li, Miao Huo, Keren Zhang, Liwei Xing and Ge Zhang

Metals 2022, 12(3), 399; https://doi.org/10.3390/met12030399 - 25 Feb 2022

Cited by 11 | Viewed by 2409

Abstract

In this paper, the microstructure and properties of a Ti/Mg alloy clad plate manufactured by explosive welding were studied. The bonding interface was inspected by ultrasonic examination (US). The microstructure and the composition of the clad were characterized by OM and SEM. Properties [...] Read more.

In this paper, the microstructure and properties of a Ti/Mg alloy clad plate manufactured by explosive welding were studied. The bonding interface was inspected by ultrasonic examination (US). The microstructure and the composition of the clad were characterized by OM and SEM. Properties were inspected by tensile test, shearing test, microhardness test and electrochemical corrosion. The results showed that the bonding interface of the clad plate was made up of straight areas and wavy areas. In straight areas, element diffusion occurred across the bonding interface. Additionally, in wavy areas, a melting zone occurred in the Mg alloy layer near to the bonding interface. Lots of light particles embedded on the melting zone. Tensile test results were comparable with the Ti sheet and the ultimate tensile strength of the clad plate demonstrated an 18% increase. The shearing strength of the clad plate was about 68–87 MPa. The microhardness of the clad plate was higher than that of the original sheets from the interface to 300 μm away. At over 300 μm, the microhardness of the clad plate decreased and approached the original sheets. Compared with the straight area, the hardness of the Mg alloy layer in the wavy area close to the interface increased by 12%. Corrosion results showed that the corrosion potential (E_corr) absolute value of the clad plate increased by 24%, and the corrosion current density (i_corr) value was 4 orders of magnitude lower, compared with the Mg alloy sheet. It was clear that the corrosion resistance of the clad plate was higher than that of the Mg alloy sheet. Cladding Mg alloy and Ti by explosive welding would improve the industrial applications of magnesium materials. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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17 pages, 6701 KiB

Open AccessArticle

Galvanic Effect and Alternating Current Corrosion of Steel in Acidic Red Soil

by Qi-Wei Wang, Jun-Xi Zhang, Yan Gao, Nian-Wei Dai, Yun-Xiang Chen, De-Yuan Lin and Xiao-Jian Xia

Metals 2022, 12(2), 296; https://doi.org/10.3390/met12020296 - 8 Feb 2022

Cited by 9 | Viewed by 2566

Abstract

Alternating current (AC) corrosion behavior of carbon steel–copper couple in acidic red soil was studied by means of the electrochemical test, mass loss, X-ray diffraction (XRD) and scanning electron microscope (SEM) characterization. Mathematical models were established to expound the impacts of AC and [...] Read more.

Alternating current (AC) corrosion behavior of carbon steel–copper couple in acidic red soil was studied by means of the electrochemical test, mass loss, X-ray diffraction (XRD) and scanning electron microscope (SEM) characterization. Mathematical models were established to expound the impacts of AC and galvanic effect on the corrosion mechanism. The results demonstrate that the corrosion rate of the galvanic couple is positively related to AC intensity. Galvanic effect and AC synergistically aggravate the corrosion of steel. The composition of α-FeOOH declines while γ-FeOOH is increased with AC interference. Based on the statistical model, the galvanic effect has a more significant influence on steel corrosion compared with AC. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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12 pages, 3395 KiB

Open AccessArticle

Effect of Cavitation Intensity on the Cavitation Erosion Behavior of 316L Stainless Steel in 3.5 wt.% NaCl Solution

by Jiaxiu Hu, Lianmin Zhang, Aili Ma, Pingli Mao and Yugui Zheng

Metals 2022, 12(2), 198; https://doi.org/10.3390/met12020198 - 21 Jan 2022

Cited by 10 | Viewed by 2734

Abstract

In this study, the cavitation erosion behavior of 316L stainless steel under different cavitation intensities in 3.5 wt.% NaCl solution was investigated with scanning electron microscopy and various electrochemical tests. Results indicated that cavitation intensity corresponding to CE amplitude of 5 μm was [...] Read more.

In this study, the cavitation erosion behavior of 316L stainless steel under different cavitation intensities in 3.5 wt.% NaCl solution was investigated with scanning electron microscopy and various electrochemical tests. Results indicated that cavitation intensity corresponding to CE amplitude of 5 μm was lower than that of the mechanical bearing capacity of passive films. When subjected to cavitation erosion (CE), Open circuit potential (OCP) shifted to the noble direction instantaneously, which was mainly attributed to enhanced oxygen transfer of the cathode due to stirring effects of CE. By contrast, high cavitation intensities corresponding to CE amplitudes of 25 μm and 55 μm exceeded the mechanical bearing capacity of passive films, causing significantly reduced OCP associated with metal dissolution of the anode from mechanical damage. Potentiostatic polarization and Mott–Schottky tests showed that 316L SS subjected to low cavitation intensities displayed good repassivation properties. However, repassivation performance was markedly weakened when high cavitation intensity was applied, resulting in weaker protection of the passive films with high carrier density. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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10 pages, 3168 KiB

Open AccessArticle

Electrospun ZnSnO₃/ZnO Composite Nanofibers and Its Ethanol-Sensitive Properties

by Songtao Dong, Xiaoyun Jin, Junlin Wei and Hongyan Wu

Metals 2022, 12(2), 196; https://doi.org/10.3390/met12020196 - 21 Jan 2022

Cited by 6 | Viewed by 2757

Abstract

In this work, a novel heterojunction based on ZnSnO₃/ZnO nanofibers was prepared by a simple electrospinning method. The crystal, structural, and surface compositional properties of ZnSnO₃ and ZnSnO₃/ZnO composite nanofibers were investigated by X-ray diffractometer (XRD), scanning electron [...] Read more.

In this work, a novel heterojunction based on ZnSnO₃/ZnO nanofibers was prepared by a simple electrospinning method. The crystal, structural, and surface compositional properties of ZnSnO₃ and ZnSnO₃/ZnO composite nanofibers were investigated by X-ray diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray photoelectron spectrometer (XPS), and Brunauer–Emmett–Teller (BET). Compared to pure ZnSnO₃ nanofibers, the ZnSnO₃/ZnO heterostructure nanofibers had high sensitivity and selectivity response with the fast response toward ethanol gas at low operational temperature. The sensing response of the sensor based on ZnSnO₃/ZnO composite nanofibers was 19.6 toward 50 ppm ethanol gas at 225 °C, which was about 1.5 times superior to that of pure ZnSnO₃ nanofibers. It can be owed mainly to the oxygen vacancies and the synergistic effect between ZnSnO₃ and ZnO. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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10 pages, 5885 KiB

Open AccessArticle

The Microstructure and Property of a Titanium-Carbon Steel Clad Plate Prepared Using Explosive Welding

by Hui Zhao

Metals 2022, 12(1), 129; https://doi.org/10.3390/met12010129 - 10 Jan 2022

Cited by 10 | Viewed by 2800

Abstract

The microstructure and properties of pure titanium (Ti)-carbon steel clad plate prepared using explosive welding were characterized. The bonding of the welding interface was inspected using C-scanning imaging technique. The microstructure and composition of the clad were characterized with optical microscopy and scanning [...] Read more.

The microstructure and properties of pure titanium (Ti)-carbon steel clad plate prepared using explosive welding were characterized. The bonding of the welding interface was inspected using C-scanning imaging technique. The microstructure and composition of the clad were characterized with optical microscopy and scanning electron microscopy. Mechanical and corrosion properties of the clad plate were investigated using tensile test, shearing test, and potentiodynamic polarization measurement. The results show that the pure titanium and carbon steel plate are joined successfully without visible defects. The interface wave is uniform. SEM observation and EDS analyses show that some melt blocks distribute at the interface waves vortices. Hardness testes results show that after heat treating, the hardness values in the titanium layer of the clad plate are similar to the original titanium plate, whereas the values at carbon steel layer increase from the interface to 300 μm away. Tensile and shearing test results indicate that the mechanical properties of the clad meet the requirements of ASTM B898 standard. Corrosion test shows that the E_corr of the clad plate is more positive, and i_corr is 1 order of magnitude lower compared to carbon steel material, suggesting that the corrosion resistance of clad plate is better than that of carbon steel material. These results suggest that the clad plate has good bonding quality and properties to meet the processing requirement and can be safely applicable in the petrochemical field. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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13 pages, 3721 KiB

Open AccessEditor’s ChoiceArticle

The Study of Graphene Oxide on the Regulations and Controls of the Sol-Gel Film Structure and Its Performance

by Yan Gao, Yadong Fan, Junxi Zhang, Xuanxuan Liu, Ning Wang and Shengjie Yang

Metals 2022, 12(1), 20; https://doi.org/10.3390/met12010020 - 22 Dec 2021

Cited by 6 | Viewed by 3084

Abstract

A facile strategy to boost anticorrosion potency of graphene oxide/silica hybrid sol-gel coating is developed through fully exploiting the capabilities of graphene oxide (GO). Together with a barrier to corrosives and crack inhibitor, GO was further explored herein as a regulator to regulate [...] Read more.

A facile strategy to boost anticorrosion potency of graphene oxide/silica hybrid sol-gel coating is developed through fully exploiting the capabilities of graphene oxide (GO). Together with a barrier to corrosives and crack inhibitor, GO was further explored herein as a regulator to regulate the gelation process and provide robust coating films with stratified microstructures and ultimately extended diffusion paths. The sol-gel coating with stratified microstructure achieved on AA5052 aluminum alloy surface afforded greatly enhanced corrosion protection capability as assessed by electrochemical measurements and immersion tests. The corrosion current density of the sample of a hybrid GO sol-gel film was about 30 times less than that of sample of pure sol-gel film sample. The regulation mechanism of GO during the film formation process and the anticorrosive protection properties of the film were discussed. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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10 pages, 21917 KiB

Open AccessArticle

Assessment of Creep Properties Using Small Punch Test for a 9%Cr-Mo-Co-B Power Plant Steel

by Xiao Tian, Saifei Zhang, Hui Xu, Taijiang Li, Baixun Yang and Min Zhang

Metals 2021, 11(12), 1996; https://doi.org/10.3390/met11121996 - 10 Dec 2021

Cited by 4 | Viewed by 2215

Abstract

The present study provides a feasible method to evaluate creep properties for a 9%Cr-Mo-Co-B power plant steel by comparing two sets of data obtained from small punch tests and conventional uniaxial creep tests. The method includes three steps: firstly, conduct a series of [...] Read more.

The present study provides a feasible method to evaluate creep properties for a 9%Cr-Mo-Co-B power plant steel by comparing two sets of data obtained from small punch tests and conventional uniaxial creep tests. The method includes three steps: firstly, conduct a series of small punch tests and conventional creep tests in different load and temperature conditions; secondly, convert the load and central deflection data obtained from the small punch test to stress and strain data; thirdly, determinate the best fit correlation factor by comparing the two sets of data in selected creep models. It is found that two sets of data show a similar trend in stress–rupture time relation, stress–minimum strain rate relation and LMP–stress relation. The correlation factor, k_sp, can effectively bridge the gap between the load in small punch test and the stress in conventional creep test. For a high-Cr martensitic heat-resistant steel named as CB2, the k_sp value 1.4 can make a good prediction for rupture time, while for minimum creep rate and the Larson–Miller parameter, the k_sp value 1.4 will lead a conservative prediction in the low-stress range. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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Review

Jump to: Research

34 pages, 2183 KiB

Open AccessReview

Corrosion Monitoring in Atmospheric Conditions: A Review

by Kateryna Popova and Tomáš Prošek

Metals 2022, 12(2), 171; https://doi.org/10.3390/met12020171 - 18 Jan 2022

Cited by 26 | Viewed by 8861

Abstract

A variety of techniques are available for monitoring metal corrosion in electrolytes. However, only some of them can be applied in the atmosphere, in which case a thin discontinuous electrolyte film forms on a surface. In this review, we describe, evaluate and compare [...] Read more.

A variety of techniques are available for monitoring metal corrosion in electrolytes. However, only some of them can be applied in the atmosphere, in which case a thin discontinuous electrolyte film forms on a surface. In this review, we describe, evaluate and compare both traditional and state-of-the-art real-time corrosion monitoring techniques to identify those suitable for atmospheric conditions. For atmospheric corrosion monitoring (ACM), electrochemical impedance spectroscopy (EIS), electrochemical noise (EN), electrical resistance (ER) probes, quartz crystal microbalance (QCM), radio-frequency identification sensors (RFID), fibre optic corrosion sensors (FOCS) and respirometry, the underlying principles, characteristics and application examples are described, and their advantages and drawbacks outlined. Finally, the techniques are compared in terms of their sensitivity, ease of setup, data processing, ability to identify underlying corrosion mechanisms and applicability in different fields of atmospheric corrosion protection and research. Full article

(This article belongs to the Special Issue Corrosion and Protection of Metallic Materials)

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