An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates
A study of the corrosion behaviour of T91 steel in molten 60 wt% NaNO<sub>3</sub>-40%KNO<sub>3</sub> has been carried out at 300, 400 and 500 °C during 1000 h. Employed techniques included potentiodynamic polarization tests, linear polarization resistance (LPR) and electroche...
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MDPI AG
2023-03-01
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| Series: | Metals |
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| Online Access: | https://www.mdpi.com/2075-4701/13/3/502 |
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| author | D. Lopez-Dominguez N. B. Gomez-Guzman J. Porcayo-Calderón R. Lopez-Sesenes A. K. Larios-Galvez E. Sarmiento-Bustos E. Rodriguez-Clemente J. G. Gonzalez-Rodriguez |
| author_facet | D. Lopez-Dominguez N. B. Gomez-Guzman J. Porcayo-Calderón R. Lopez-Sesenes A. K. Larios-Galvez E. Sarmiento-Bustos E. Rodriguez-Clemente J. G. Gonzalez-Rodriguez |
| author_sort | D. Lopez-Dominguez |
| collection | DOAJ |
| description | A study of the corrosion behaviour of T91 steel in molten 60 wt% NaNO<sub>3</sub>-40%KNO<sub>3</sub> has been carried out at 300, 400 and 500 °C during 1000 h. Employed techniques included potentiodynamic polarization tests, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements. Experiments were complemented by detailed scanning electronic measurements and X-ray diffraction studies. Polarization curves revealed the existence of a passive layer formed onto the steel, composed mainly of Cr<sub>2</sub>O<sub>3</sub>, FeCr<sub>2</sub>O<sub>4</sub>, NaCrO<sub>4</sub> and K<sub>2</sub>Fe<sub>2</sub>O<sub>4</sub>. Corrosion current density values increased, whereas the polarization resistance value decreased more than one order of magnitude as the testing temperature increased. EIS tests indicated a charge transfer controlled corrosion process, regardless of the testing temperature, and that the double electrochemical layer resistance decreased with the temperature. |
| first_indexed | 2024-03-11T06:11:45Z |
| format | Article |
| id | doaj.art-db6bf9e9c13f4fe181ab1338a2eda011 |
| institution | Directory Open Access Journal |
| issn | 2075-4701 |
| language | English |
| last_indexed | 2024-03-11T06:11:45Z |
| publishDate | 2023-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Metals |
| spelling | doaj.art-db6bf9e9c13f4fe181ab1338a2eda0112023-11-17T12:38:39ZengMDPI AGMetals2075-47012023-03-0113350210.3390/met13030502An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten NitratesD. Lopez-Dominguez0N. B. Gomez-Guzman1J. Porcayo-Calderón2R. Lopez-Sesenes3A. K. Larios-Galvez4E. Sarmiento-Bustos5E. Rodriguez-Clemente6J. G. Gonzalez-Rodriguez7Research Centre in Engineering and Applied Sciences, Morelos State Autonomous University, Cuernavaca 62209, MexicoResearch Centre in Engineering and Applied Sciences, Morelos State Autonomous University, Cuernavaca 62209, MexicoChemical Engineering and Metallurgy Department, Sonora State University, Sonora 83000, MexicoChemical Science and Engineering Faculty, Morelos State Autonomous University, Cuernavaca 62209, MexicoPhysical Sciences Institute, National Autonomous University of Mexico, Cuernavaca 62209, MexicoIndustrial Mechanical Division, Morelos State Emiliano Zapata Technological University, Emiliano Zapata 62565, MexicoBasic Sciences Department, Metropolitan Azcapotzalco Autonomous University, Mexico City 02080, MexicoResearch Centre in Engineering and Applied Sciences, Morelos State Autonomous University, Cuernavaca 62209, MexicoA study of the corrosion behaviour of T91 steel in molten 60 wt% NaNO<sub>3</sub>-40%KNO<sub>3</sub> has been carried out at 300, 400 and 500 °C during 1000 h. Employed techniques included potentiodynamic polarization tests, linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS) measurements. Experiments were complemented by detailed scanning electronic measurements and X-ray diffraction studies. Polarization curves revealed the existence of a passive layer formed onto the steel, composed mainly of Cr<sub>2</sub>O<sub>3</sub>, FeCr<sub>2</sub>O<sub>4</sub>, NaCrO<sub>4</sub> and K<sub>2</sub>Fe<sub>2</sub>O<sub>4</sub>. Corrosion current density values increased, whereas the polarization resistance value decreased more than one order of magnitude as the testing temperature increased. EIS tests indicated a charge transfer controlled corrosion process, regardless of the testing temperature, and that the double electrochemical layer resistance decreased with the temperature.https://www.mdpi.com/2075-4701/13/3/502T91 steelmolten nitrateselectrochemical impedance spectroscopy |
| spellingShingle | D. Lopez-Dominguez N. B. Gomez-Guzman J. Porcayo-Calderón R. Lopez-Sesenes A. K. Larios-Galvez E. Sarmiento-Bustos E. Rodriguez-Clemente J. G. Gonzalez-Rodriguez An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates Metals T91 steel molten nitrates electrochemical impedance spectroscopy |
| title | An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates |
| title_full | An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates |
| title_fullStr | An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates |
| title_full_unstemmed | An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates |
| title_short | An Electrochemical Study of the Corrosion Behaviour of T91 Steel in Molten Nitrates |
| title_sort | electrochemical study of the corrosion behaviour of t91 steel in molten nitrates |
| topic | T91 steel molten nitrates electrochemical impedance spectroscopy |
| url | https://www.mdpi.com/2075-4701/13/3/502 |
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