Pub Date : 2023-01-15DOI: 10.1080/1478422X.2022.2163335
S. Goh, L. T. Tan, H. Gan, Y. Foo, K. H. Goh, H. S. Lee
ABSTRACT A study has been conducted to measure the distribution of temperature, relative humidity and corrosivity due to uniform corrosion along the Mass Rapid Transit (MRT) North East Line (NEL) tunnel in Singapore. The corrosion rates of carbon steel 1010 and zinc coupons at the buffer areas of ten stations and five cross passages along the NEL were monitored over a period of one year. The median temperatures were between 31 and 36°C while the median relative humidity varied between 43 and 53%. At all exposure sites, the values of relative humidity corresponding to the 75th percentile values were below 60%, with very few data points registering above 80%. The cross passages showed a lower degree of fluctuations in the temperature and relative humidity compared to the buffer areas. The corrosivity levels showed some differences between exposure sites, but their values were generally low and could be categorised as C1 according to the ISO 9223:2012 categorisation. A set of procedures for an accelerated laboratory test to approximate the corrosion in the tunnel was also studied. The test procedures involved the exposure to a salt fog containing 0.12% Na2SO4 + 0.05% NaCl, followed by a drying phase and subsequent exposure to a constant temperature of 40°C and a constant relative humidity of 60%. It was found that after exposure for 80 h, the accelerated tests were able to generate the degree of corrosion observed in the most severe conditions in the field.
{"title":"Accelerated corrosion test and field test of steel and zinc coupons at buffer areas and cross passages in a mass rapid transit tunnel","authors":"S. Goh, L. T. Tan, H. Gan, Y. Foo, K. H. Goh, H. S. Lee","doi":"10.1080/1478422X.2022.2163335","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2163335","url":null,"abstract":"ABSTRACT A study has been conducted to measure the distribution of temperature, relative humidity and corrosivity due to uniform corrosion along the Mass Rapid Transit (MRT) North East Line (NEL) tunnel in Singapore. The corrosion rates of carbon steel 1010 and zinc coupons at the buffer areas of ten stations and five cross passages along the NEL were monitored over a period of one year. The median temperatures were between 31 and 36°C while the median relative humidity varied between 43 and 53%. At all exposure sites, the values of relative humidity corresponding to the 75th percentile values were below 60%, with very few data points registering above 80%. The cross passages showed a lower degree of fluctuations in the temperature and relative humidity compared to the buffer areas. The corrosivity levels showed some differences between exposure sites, but their values were generally low and could be categorised as C1 according to the ISO 9223:2012 categorisation. A set of procedures for an accelerated laboratory test to approximate the corrosion in the tunnel was also studied. The test procedures involved the exposure to a salt fog containing 0.12% Na2SO4 + 0.05% NaCl, followed by a drying phase and subsequent exposure to a constant temperature of 40°C and a constant relative humidity of 60%. It was found that after exposure for 80 h, the accelerated tests were able to generate the degree of corrosion observed in the most severe conditions in the field.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"230 - 242"},"PeriodicalIF":1.8,"publicationDate":"2023-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48909605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-13DOI: 10.1080/1478422X.2023.2165634
Yingxue Liu, Huijie Huangfu, Shuai Gao, Xugeng Guo, Li Wang
ABSTRACT Herein, we prepare two types of MgAl-LDHs coatings single-doped by imidazolium ionic liquid 1-decyl-3-methylimidazolium bromide ([Demim]Br) or sodium dodecylbenzenesulphonate (SDBS) and double-doped by [Demim]Br and SDBS on AZ31B Mg alloy by using an in-situ hydrothermal treatment. Their surface morphology and corrosion resistance immersed in 3.5 wt-% NaCl solution are explored. Our results suggest that the double doping of [Demim]Br and SDBS will change the surface morphology of the coating and a uniform and dense film is observed in the double-doped MgAl-LDHs, which is denser than those of the two single-doped MgAl-LDHs coatings, thus providing a superior corrosion resistance. Such an improvement can be ascribed to the synergetic inhibition effect of [Demim]Br and SDBS against the corrosion of the Mg alloy substrate. More importantly, the charge transfer resistance of the sample coated with the double-doped MgAl-LDHs is still high after 3 d of immersion, benefiting from the excellent self-healing effect.
{"title":"Enhanced corrosion protection of AZ31B magnesium alloy by MgAl-LDHs composite coatings double-doped with imidazolium ionic liquid and sodium dodecylbenzenesulphonate","authors":"Yingxue Liu, Huijie Huangfu, Shuai Gao, Xugeng Guo, Li Wang","doi":"10.1080/1478422X.2023.2165634","DOIUrl":"https://doi.org/10.1080/1478422X.2023.2165634","url":null,"abstract":"ABSTRACT Herein, we prepare two types of MgAl-LDHs coatings single-doped by imidazolium ionic liquid 1-decyl-3-methylimidazolium bromide ([Demim]Br) or sodium dodecylbenzenesulphonate (SDBS) and double-doped by [Demim]Br and SDBS on AZ31B Mg alloy by using an in-situ hydrothermal treatment. Their surface morphology and corrosion resistance immersed in 3.5 wt-% NaCl solution are explored. Our results suggest that the double doping of [Demim]Br and SDBS will change the surface morphology of the coating and a uniform and dense film is observed in the double-doped MgAl-LDHs, which is denser than those of the two single-doped MgAl-LDHs coatings, thus providing a superior corrosion resistance. Such an improvement can be ascribed to the synergetic inhibition effect of [Demim]Br and SDBS against the corrosion of the Mg alloy substrate. More importantly, the charge transfer resistance of the sample coated with the double-doped MgAl-LDHs is still high after 3 d of immersion, benefiting from the excellent self-healing effect.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"259 - 269"},"PeriodicalIF":1.8,"publicationDate":"2023-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46138892","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-12DOI: 10.1080/1478422X.2023.2165238
J. At, M. Arshad, Mathew Kuruvilla, A. Joseph
ABSTRACT Aqueous leaves extract of Clerodendrum infortunatum (CIW) was used as inhibitor for mild steel corrosion in 0.5 N HCl. Inhibition efficiency decreases with temperature. The presence of 1-heptatriacotanol, the diterpene alcohols like phytol and 3, 7, 11, 15 tetramethyl-2-hexadecen-1-ol are identified as major constituents through GC-MS analysis of CIW. The electronic properties and inhibition efficiency of these compounds were evaluated using DFT and material studio software. The donor–acceptor type interactions resulting from the migration of lone pair of electrons of the ‘O’ atom of these molecules to the vacant ‘d’ orbital of the metal is evident from these calculations. The reduction in the double-layer capacitance with the incremental addition of CIW is noticed. CIW offers mixed inhibition with anodic predominance. CIW forms a multimolecular layer on the metal surface obeying the Temkin isotherm model. Surface perturbations were followed qualitatively by SEM, stereomicroscope and XPS.
{"title":"Computational modelling and correlation of physical parameters of 1-heptatriacotanol, phytol and 3, 7, 11, 15-tetra methyl-2-hexadecen-1-ol with the corrosion inhibition efficiency of CIW for mild steel in HCl","authors":"J. At, M. Arshad, Mathew Kuruvilla, A. Joseph","doi":"10.1080/1478422X.2023.2165238","DOIUrl":"https://doi.org/10.1080/1478422X.2023.2165238","url":null,"abstract":"ABSTRACT Aqueous leaves extract of Clerodendrum infortunatum (CIW) was used as inhibitor for mild steel corrosion in 0.5 N HCl. Inhibition efficiency decreases with temperature. The presence of 1-heptatriacotanol, the diterpene alcohols like phytol and 3, 7, 11, 15 tetramethyl-2-hexadecen-1-ol are identified as major constituents through GC-MS analysis of CIW. The electronic properties and inhibition efficiency of these compounds were evaluated using DFT and material studio software. The donor–acceptor type interactions resulting from the migration of lone pair of electrons of the ‘O’ atom of these molecules to the vacant ‘d’ orbital of the metal is evident from these calculations. The reduction in the double-layer capacitance with the incremental addition of CIW is noticed. CIW offers mixed inhibition with anodic predominance. CIW forms a multimolecular layer on the metal surface obeying the Temkin isotherm model. Surface perturbations were followed qualitatively by SEM, stereomicroscope and XPS.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"243 - 258"},"PeriodicalIF":1.8,"publicationDate":"2023-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46541660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-03DOI: 10.1080/1478422X.2022.2162661
E. Mardaras, N. Imaz, R. González-Martínez, E. García-Lecina, E. Aguado
ABSTRACT Corrosion behaviour of 2024-T6 castings produced by sand mould and metallic mould has been studied in media with different sodium chloride concentrations and pH values, using electrochemical techniques and scanning electron microscope. Corrosion rates and anodic and cathodic reaction kinetics are detailed to provide a fundamental understanding of the electrochemical behaviour of 2024-T6 at different conditions. The study shows a different corrosion mechanism depending on the pH. At pH 12, the more negative values of E corr confirmed that the alkalinisation of aluminium incites the dissolution of the Al substrate. The effect of chloride concentration is reflected in shifts of E corr towards more negative values. The research on the effect of the used mould demonstrates that the impact of the casting process in the cooling rate affects the pitting corrosion resistance.
{"title":"Influence of the casting process on corrosion behaviour of 2024-T6 aluminium alloy in different conditions of pH and NaCl concentration","authors":"E. Mardaras, N. Imaz, R. González-Martínez, E. García-Lecina, E. Aguado","doi":"10.1080/1478422X.2022.2162661","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2162661","url":null,"abstract":"ABSTRACT Corrosion behaviour of 2024-T6 castings produced by sand mould and metallic mould has been studied in media with different sodium chloride concentrations and pH values, using electrochemical techniques and scanning electron microscope. Corrosion rates and anodic and cathodic reaction kinetics are detailed to provide a fundamental understanding of the electrochemical behaviour of 2024-T6 at different conditions. The study shows a different corrosion mechanism depending on the pH. At pH 12, the more negative values of E corr confirmed that the alkalinisation of aluminium incites the dissolution of the Al substrate. The effect of chloride concentration is reflected in shifts of E corr towards more negative values. The research on the effect of the used mould demonstrates that the impact of the casting process in the cooling rate affects the pitting corrosion resistance.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"214 - 222"},"PeriodicalIF":1.8,"publicationDate":"2023-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41695972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.1080/1478422X.2022.2161336
M. Gavryushina, A. Marshakov, Yu. S. Panchenko
ABSTRACT The random forest (RF) algorithm was used to develop two models for predicting the first-year corrosion losses (C 1) of carbon steel in open air in various regions of the world. The first RF model built using combined databases of international programmes ISO CORRAG, MICAT and ECE/UN and tests conducted in Russia is intended for estimation of C 1 in various types of atmospheres in various regions of the world. The second RF model enables the prediction of C 1 in continental areas of the world. The accuracy of C 1 predictions by the two RF and two dose–response functions, i.e. the function presented in ISO 9223 standard and the new version for a non-marine atmosphere, was compared. The reliability of the two RF models was shown to be significantly higher than that of the dose–response functions with exception of the predictions for corrosion losses of carbon steel in regions of Russia with a cold climate.
{"title":"Application of the random forest algorithm to predict the corrosion losses of carbon steel over the first year of exposure in various regions of the world","authors":"M. Gavryushina, A. Marshakov, Yu. S. Panchenko","doi":"10.1080/1478422X.2022.2161336","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2161336","url":null,"abstract":"ABSTRACT The random forest (RF) algorithm was used to develop two models for predicting the first-year corrosion losses (C 1) of carbon steel in open air in various regions of the world. The first RF model built using combined databases of international programmes ISO CORRAG, MICAT and ECE/UN and tests conducted in Russia is intended for estimation of C 1 in various types of atmospheres in various regions of the world. The second RF model enables the prediction of C 1 in continental areas of the world. The accuracy of C 1 predictions by the two RF and two dose–response functions, i.e. the function presented in ISO 9223 standard and the new version for a non-marine atmosphere, was compared. The reliability of the two RF models was shown to be significantly higher than that of the dose–response functions with exception of the predictions for corrosion losses of carbon steel in regions of Russia with a cold climate.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"205 - 213"},"PeriodicalIF":1.8,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43089957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.1080/1478422X.2022.2162662
Yu Ji, Yingchang Mao, Lihua Dang, Da-Hai Xia, Wenbin Hu
ABSTRACT The localised corrosion of aluminium alloy (AA) 5083-H111 in 3.5 wt-% NaCl solution was studied by combing scanning electron microscope (SEM), focused ion beam (FIB) and transmission electron microscopy (TEM) techniques. It was found that the Ti-rich intermetallic particles (IMPs) served as the cathodes and triggered the dissolution of its adjacent Al matrix; as a result, a trench was formed between the IMP and its surrounding Al matrix. Raised ‘circles’ were identified on the alloy surface at the periphery of the IMPs, which was considered to be the cathodic region on which corrosion products deposited. A sub-surface that consisted of fine Al grains and corroded Al–Mg phases were observed under the raised ‘circle’ region.
{"title":"A high-resolution characterisation of localised corrosion of AA5083-H111 in simulated seawater by TEM","authors":"Yu Ji, Yingchang Mao, Lihua Dang, Da-Hai Xia, Wenbin Hu","doi":"10.1080/1478422X.2022.2162662","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2162662","url":null,"abstract":"ABSTRACT The localised corrosion of aluminium alloy (AA) 5083-H111 in 3.5 wt-% NaCl solution was studied by combing scanning electron microscope (SEM), focused ion beam (FIB) and transmission electron microscopy (TEM) techniques. It was found that the Ti-rich intermetallic particles (IMPs) served as the cathodes and triggered the dissolution of its adjacent Al matrix; as a result, a trench was formed between the IMP and its surrounding Al matrix. Raised ‘circles’ were identified on the alloy surface at the periphery of the IMPs, which was considered to be the cathodic region on which corrosion products deposited. A sub-surface that consisted of fine Al grains and corroded Al–Mg phases were observed under the raised ‘circle’ region.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"223 - 229"},"PeriodicalIF":1.8,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42251063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.1080/1478422X.2022.2161122
Xingxing Zhou, Qiangsheng Dong, Dali Wei, Jing Bai, F. Xue, Baosen Zhang, Z. Ba, Zhang-zhong Wang
ABSTRACT Metal corrosion has been one of the most urgent problems bringing about great economic loss and life threats worldwide. Corrosion inhibitors can prevent metal from corrosion when directly added to corrosive media, which is a low-cost and efficient strategy towards corrosion protection. However, the corrosion protection ability cannot be durable without continuous additions of corrosion inhibitors. Micro/nano-containers encapsulated with corrosion inhibitors offer promising opportunities for delaying the corrosion process and prolonging the service period, regarded as smart corrosion inhibitors that can respond to stimuli spontaneously and release on demand. The review focuses on the diverse ambient stimuli and actively responsive mechanisms of smart corrosion inhibitors. Furthermore, the present drawbacks and underexplored possibilities of current research studies are pointed out, and future perspectives are prospected for smart corrosion inhibitor applications.
{"title":"Smart corrosion inhibitors for controlled release: a review","authors":"Xingxing Zhou, Qiangsheng Dong, Dali Wei, Jing Bai, F. Xue, Baosen Zhang, Z. Ba, Zhang-zhong Wang","doi":"10.1080/1478422X.2022.2161122","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2161122","url":null,"abstract":"ABSTRACT Metal corrosion has been one of the most urgent problems bringing about great economic loss and life threats worldwide. Corrosion inhibitors can prevent metal from corrosion when directly added to corrosive media, which is a low-cost and efficient strategy towards corrosion protection. However, the corrosion protection ability cannot be durable without continuous additions of corrosion inhibitors. Micro/nano-containers encapsulated with corrosion inhibitors offer promising opportunities for delaying the corrosion process and prolonging the service period, regarded as smart corrosion inhibitors that can respond to stimuli spontaneously and release on demand. The review focuses on the diverse ambient stimuli and actively responsive mechanisms of smart corrosion inhibitors. Furthermore, the present drawbacks and underexplored possibilities of current research studies are pointed out, and future perspectives are prospected for smart corrosion inhibitor applications.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"190 - 204"},"PeriodicalIF":1.8,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42508594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Corrosion tests of Ni-based alloy Inconel 740H were carried out in supercritical carbon dioxide (S-CO2) at 650–700°C under 25 MPa. The corrosion kinetics were measured by weight change as a function of time, and the surface oxide layers were characterised and identified by a series of characterisation methods. It is found that Inconel 740H experienced general oxidation, localised exfoliation and internal oxidation. A dense Cr2O3 oxide scale rapidly formed on the surface of Inconel 740H at 650–700°C, resulting in good general corrosion resistance. Nodular oxidation was triggered by Ti-rich and Nb-rich oxides. Internal oxidation selectively oxidised Al. The causes of oxide-induced exfoliation are discussed.
{"title":"Corrosion behaviour of Ni-based alloy Inconel 740H in supercritical carbon dioxide at 650–700°C","authors":"Bo-Qi Xiao, Naiqiang Zhang, Kaiyang Li, Zhongliang Zhu, Tianyi Zhang, Mi Zhou","doi":"10.1080/1478422X.2022.2157534","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2157534","url":null,"abstract":"ABSTRACT Corrosion tests of Ni-based alloy Inconel 740H were carried out in supercritical carbon dioxide (S-CO2) at 650–700°C under 25 MPa. The corrosion kinetics were measured by weight change as a function of time, and the surface oxide layers were characterised and identified by a series of characterisation methods. It is found that Inconel 740H experienced general oxidation, localised exfoliation and internal oxidation. A dense Cr2O3 oxide scale rapidly formed on the surface of Inconel 740H at 650–700°C, resulting in good general corrosion resistance. Nodular oxidation was triggered by Ti-rich and Nb-rich oxides. Internal oxidation selectively oxidised Al. The causes of oxide-induced exfoliation are discussed.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"180 - 189"},"PeriodicalIF":1.8,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44040192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-10DOI: 10.1080/1478422X.2022.2154735
Chenglong Zhang, M. Zhu, Yongfeng Yuan, Shao-yi Guo
ABSTRACT The corrosion behaviour of equiatomic CoCrFeNi and CoCrFeNiMn high entropy alloys manufactured by the vacuum arc melting were studied in 3.5 wt-% NaCl solution. And the reasons for the differences in corrosion resistance were investigated in terms of microstructure, electrochemical behaviour and oxide film. The results show that the two alloys exhibit different corrosion characteristics, with CoCrFeNi alloy displaying typical passivation characteristics and CoCrFeNiMn alloy exhibiting activation behaviour. The CoCrFeNi HEA with compact and protective passive film has lower corrosion current density, larger film resistance and polarisation resistance, meaning a lower corrosion rate and superior corrosion resistance compared with those of CoCrFeNiMn alloy. Moreover, CoCrFeNiMn alloy forms a discontinuous and loose corrosion product film with higher Mn content and lower contents of Cr, Fe and Co compared to the matrix, which decreases its protection performance. The addition of Mn changes the electrochemical behaviour, and higher Mn oxides/hydroxides within oxide film are unfavourable to forming a stable passive film. GRAPHICAL ABSTRACT
{"title":"The effect of Mn addition on corrosion behaviour of equiatomic CoCrFeNi high entropy alloys in NaCl solution","authors":"Chenglong Zhang, M. Zhu, Yongfeng Yuan, Shao-yi Guo","doi":"10.1080/1478422X.2022.2154735","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2154735","url":null,"abstract":"ABSTRACT The corrosion behaviour of equiatomic CoCrFeNi and CoCrFeNiMn high entropy alloys manufactured by the vacuum arc melting were studied in 3.5 wt-% NaCl solution. And the reasons for the differences in corrosion resistance were investigated in terms of microstructure, electrochemical behaviour and oxide film. The results show that the two alloys exhibit different corrosion characteristics, with CoCrFeNi alloy displaying typical passivation characteristics and CoCrFeNiMn alloy exhibiting activation behaviour. The CoCrFeNi HEA with compact and protective passive film has lower corrosion current density, larger film resistance and polarisation resistance, meaning a lower corrosion rate and superior corrosion resistance compared with those of CoCrFeNiMn alloy. Moreover, CoCrFeNiMn alloy forms a discontinuous and loose corrosion product film with higher Mn content and lower contents of Cr, Fe and Co compared to the matrix, which decreases its protection performance. The addition of Mn changes the electrochemical behaviour, and higher Mn oxides/hydroxides within oxide film are unfavourable to forming a stable passive film. GRAPHICAL ABSTRACT","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"169 - 179"},"PeriodicalIF":1.8,"publicationDate":"2022-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44588247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-08DOI: 10.1080/1478422X.2022.2152172
Bhaskarjyoti Das, M. Yadav, S. Kundu, Tapendu Mandal
ABSTRACT In this study, the corrosion behavior of turmeric-coated AZ51 alloy is studied in a simulated bodily fluid (SBF) and then correlated using different characterization techniques. Optical microstructures of all the samples reveal the presence of grains of the α-Mg alloy and precipitates of β-Mg17Al12. Two well-defined peaks were obtained from the XRD patterns -Mg and Mg17Al12, correlating with the optical microscopy results. The potentiodynamic polarisation investigation illustrates the corrosion behavior of uncoated (UC) and turmeric-coated magnesium samples dipped for 24 (DC-24), 48 (DC-48), and 96 hours (DC-96). Results confirmed that the DC-48 sample shows the maximum corrosion resistance among all the samples, and the EIS study correlates well with the study. The mineralization study confirms that the DC-48 sample has the maximum corrosion resistance due to the uniformity and compact nature of the coating.
{"title":"Evaluation of corrosion behaviour of turmeric-coated AZ51 alloy in simulated body fluid for biomedical applications","authors":"Bhaskarjyoti Das, M. Yadav, S. Kundu, Tapendu Mandal","doi":"10.1080/1478422X.2022.2152172","DOIUrl":"https://doi.org/10.1080/1478422X.2022.2152172","url":null,"abstract":"ABSTRACT In this study, the corrosion behavior of turmeric-coated AZ51 alloy is studied in a simulated bodily fluid (SBF) and then correlated using different characterization techniques. Optical microstructures of all the samples reveal the presence of grains of the α-Mg alloy and precipitates of β-Mg17Al12. Two well-defined peaks were obtained from the XRD patterns -Mg and Mg17Al12, correlating with the optical microscopy results. The potentiodynamic polarisation investigation illustrates the corrosion behavior of uncoated (UC) and turmeric-coated magnesium samples dipped for 24 (DC-24), 48 (DC-48), and 96 hours (DC-96). Results confirmed that the DC-48 sample shows the maximum corrosion resistance among all the samples, and the EIS study correlates well with the study. The mineralization study confirms that the DC-48 sample has the maximum corrosion resistance due to the uniformity and compact nature of the coating.","PeriodicalId":10711,"journal":{"name":"Corrosion Engineering, Science and Technology","volume":"58 1","pages":"124 - 137"},"PeriodicalIF":1.8,"publicationDate":"2022-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49299928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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