The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions
- Autores
- Tomachuk, C. R.; Culcasi, José Daniel; Elsner, Cecilia Ines; Costa, Isolda; Di Sarli, Alejandro Ramón
- Año de publicación
- 2014
- Idioma
- inglés
- Tipo de recurso
- documento de conferencia
- Estado
- versión publicada
- Descripción
- Electroplated zinc coatings have been largely employed as active galvanic protection for steel substrates. However, as zinc is highly electrochemically active, its corrosion rate may be very high. For this reason, a post treatment to increase the lifetime of the coatings is necessary, which, in industrial practice, consists of immersion in a chemical bath that forms a conversion layer on plated zinc. This layer must be a dielectric passive coating with high corrosion resistance that also offers good adherence to paints. The main problem of conventionally used post treatments is the presence of Cr6+ salts which are carcinogenic substances whose usage was forbidden by European regulations. In this work the effect of trivalent chromium and Co ions in solution of passivation treatments on the corrosion resistance of electrogalvanised steel has been investigated in 0.1 M Na2SO4 solution by electrochemical impedance spectroscopy (EIS) and polarization curves. Prior and after the corrosion tests, the chemical composition and morphology of the electrogalvanised surface was characterized by SEM and XPS. The EIS results showed that impedance values associated to the surface with Cr3+ + Co treatments were inferior to those exhibited by the Cr6+ treated ones. The higher impedances related to the Cr6+ samples could be explained by the self-healing effect of this type of coating. The SEM analyses revealed coating cracks associated to the surface of the Cr6+ treated samples whereas for those treated in the Cr3+ + Co solution, elongated fissures were seen. These last samples presented inferior corrosion resistance to that of the Cr6+ passivated ones. The cobalt addition to the trivalent chromium containing solution was not sufficient to increase the corrosion resistance to acceptable levels in comparison to the Cr6+ conversion coating.
Fil: Tomachuk, C. R.. Universidade de Sao Paulo; Brasil
Fil: Culcasi, José Daniel. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Mecánica. Laboratorio de Investigación de Metalurgia Física; Argentina
Fil: Elsner, Cecilia Ines. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina
Fil: Costa, Isolda. Universidade de Sao Paulo; Brasil
Fil: Di Sarli, Alejandro Ramón. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina
65th Annual Meeting of the International Society of Electrochemistry
Lausanne
Suiza
International Society of Electrochemistry - Materia
-
GALVANIZED STEEL
COATINGS
PASSIVATION
TRIVALENT CHROMIUM - Nivel de accesibilidad
- acceso abierto
- Condiciones de uso
- https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
- Repositorio
.jpg)
- Institución
- Consejo Nacional de Investigaciones Científicas y Técnicas
- OAI Identificador
- oai:ri.conicet.gov.ar:11336/239147
Ver los metadatos del registro completo
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The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ionsTomachuk, C. R.Culcasi, José DanielElsner, Cecilia InesCosta, IsoldaDi Sarli, Alejandro RamónGALVANIZED STEELCOATINGSPASSIVATIONTRIVALENT CHROMIUMhttps://purl.org/becyt/ford/2.5https://purl.org/becyt/ford/2Electroplated zinc coatings have been largely employed as active galvanic protection for steel substrates. However, as zinc is highly electrochemically active, its corrosion rate may be very high. For this reason, a post treatment to increase the lifetime of the coatings is necessary, which, in industrial practice, consists of immersion in a chemical bath that forms a conversion layer on plated zinc. This layer must be a dielectric passive coating with high corrosion resistance that also offers good adherence to paints. The main problem of conventionally used post treatments is the presence of Cr6+ salts which are carcinogenic substances whose usage was forbidden by European regulations. In this work the effect of trivalent chromium and Co ions in solution of passivation treatments on the corrosion resistance of electrogalvanised steel has been investigated in 0.1 M Na2SO4 solution by electrochemical impedance spectroscopy (EIS) and polarization curves. Prior and after the corrosion tests, the chemical composition and morphology of the electrogalvanised surface was characterized by SEM and XPS. The EIS results showed that impedance values associated to the surface with Cr3+ + Co treatments were inferior to those exhibited by the Cr6+ treated ones. The higher impedances related to the Cr6+ samples could be explained by the self-healing effect of this type of coating. The SEM analyses revealed coating cracks associated to the surface of the Cr6+ treated samples whereas for those treated in the Cr3+ + Co solution, elongated fissures were seen. These last samples presented inferior corrosion resistance to that of the Cr6+ passivated ones. The cobalt addition to the trivalent chromium containing solution was not sufficient to increase the corrosion resistance to acceptable levels in comparison to the Cr6+ conversion coating.Fil: Tomachuk, C. R.. Universidade de Sao Paulo; BrasilFil: Culcasi, José Daniel. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Mecánica. Laboratorio de Investigación de Metalurgia Física; ArgentinaFil: Elsner, Cecilia Ines. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Costa, Isolda. Universidade de Sao Paulo; BrasilFil: Di Sarli, Alejandro Ramón. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina65th Annual Meeting of the International Society of ElectrochemistryLausanneSuizaInternational Society of ElectrochemistryInternational Society of Electrochemistry2014info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/conferenceObjectCongresoBookhttp://purl.org/coar/resource_type/c_5794info:ar-repo/semantics/documentoDeConferenciaapplication/pdfapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/239147The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions; 65th Annual Meeting of the International Society of Electrochemistry; Lausanne; Suiza; 2014; 1-1CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/https://www.ise-online.org/ise-conferences/annmeet/folder/2014-LAUSANNE-BoA.pdfInternacionalinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by-nc-sa/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:14:57Zoai:ri.conicet.gov.ar:11336/239147instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 11:14:57.698CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse |
| dc.title.none.fl_str_mv |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| title |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| spellingShingle |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions Tomachuk, C. R. GALVANIZED STEEL COATINGS PASSIVATION TRIVALENT CHROMIUM |
| title_short |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| title_full |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| title_fullStr |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| title_full_unstemmed |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| title_sort |
The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions |
| dc.creator.none.fl_str_mv |
Tomachuk, C. R. Culcasi, José Daniel Elsner, Cecilia Ines Costa, Isolda Di Sarli, Alejandro Ramón |
| author |
Tomachuk, C. R. |
| author_facet |
Tomachuk, C. R. Culcasi, José Daniel Elsner, Cecilia Ines Costa, Isolda Di Sarli, Alejandro Ramón |
| author_role |
author |
| author2 |
Culcasi, José Daniel Elsner, Cecilia Ines Costa, Isolda Di Sarli, Alejandro Ramón |
| author2_role |
author author author author |
| dc.subject.none.fl_str_mv |
GALVANIZED STEEL COATINGS PASSIVATION TRIVALENT CHROMIUM |
| topic |
GALVANIZED STEEL COATINGS PASSIVATION TRIVALENT CHROMIUM |
| purl_subject.fl_str_mv |
https://purl.org/becyt/ford/2.5 https://purl.org/becyt/ford/2 |
| dc.description.none.fl_txt_mv |
Electroplated zinc coatings have been largely employed as active galvanic protection for steel substrates. However, as zinc is highly electrochemically active, its corrosion rate may be very high. For this reason, a post treatment to increase the lifetime of the coatings is necessary, which, in industrial practice, consists of immersion in a chemical bath that forms a conversion layer on plated zinc. This layer must be a dielectric passive coating with high corrosion resistance that also offers good adherence to paints. The main problem of conventionally used post treatments is the presence of Cr6+ salts which are carcinogenic substances whose usage was forbidden by European regulations. In this work the effect of trivalent chromium and Co ions in solution of passivation treatments on the corrosion resistance of electrogalvanised steel has been investigated in 0.1 M Na2SO4 solution by electrochemical impedance spectroscopy (EIS) and polarization curves. Prior and after the corrosion tests, the chemical composition and morphology of the electrogalvanised surface was characterized by SEM and XPS. The EIS results showed that impedance values associated to the surface with Cr3+ + Co treatments were inferior to those exhibited by the Cr6+ treated ones. The higher impedances related to the Cr6+ samples could be explained by the self-healing effect of this type of coating. The SEM analyses revealed coating cracks associated to the surface of the Cr6+ treated samples whereas for those treated in the Cr3+ + Co solution, elongated fissures were seen. These last samples presented inferior corrosion resistance to that of the Cr6+ passivated ones. The cobalt addition to the trivalent chromium containing solution was not sufficient to increase the corrosion resistance to acceptable levels in comparison to the Cr6+ conversion coating. Fil: Tomachuk, C. R.. Universidade de Sao Paulo; Brasil Fil: Culcasi, José Daniel. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Mecánica. Laboratorio de Investigación de Metalurgia Física; Argentina Fil: Elsner, Cecilia Ines. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina Fil: Costa, Isolda. Universidade de Sao Paulo; Brasil Fil: Di Sarli, Alejandro Ramón. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentina 65th Annual Meeting of the International Society of Electrochemistry Lausanne Suiza International Society of Electrochemistry |
| description |
Electroplated zinc coatings have been largely employed as active galvanic protection for steel substrates. However, as zinc is highly electrochemically active, its corrosion rate may be very high. For this reason, a post treatment to increase the lifetime of the coatings is necessary, which, in industrial practice, consists of immersion in a chemical bath that forms a conversion layer on plated zinc. This layer must be a dielectric passive coating with high corrosion resistance that also offers good adherence to paints. The main problem of conventionally used post treatments is the presence of Cr6+ salts which are carcinogenic substances whose usage was forbidden by European regulations. In this work the effect of trivalent chromium and Co ions in solution of passivation treatments on the corrosion resistance of electrogalvanised steel has been investigated in 0.1 M Na2SO4 solution by electrochemical impedance spectroscopy (EIS) and polarization curves. Prior and after the corrosion tests, the chemical composition and morphology of the electrogalvanised surface was characterized by SEM and XPS. The EIS results showed that impedance values associated to the surface with Cr3+ + Co treatments were inferior to those exhibited by the Cr6+ treated ones. The higher impedances related to the Cr6+ samples could be explained by the self-healing effect of this type of coating. The SEM analyses revealed coating cracks associated to the surface of the Cr6+ treated samples whereas for those treated in the Cr3+ + Co solution, elongated fissures were seen. These last samples presented inferior corrosion resistance to that of the Cr6+ passivated ones. The cobalt addition to the trivalent chromium containing solution was not sufficient to increase the corrosion resistance to acceptable levels in comparison to the Cr6+ conversion coating. |
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2014 |
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2014 |
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The protection of electrogalvanised steel by passivation treatment with trivalent chromium and cobalt ions; 65th Annual Meeting of the International Society of Electrochemistry; Lausanne; Suiza; 2014; 1-1 CONICET Digital CONICET |
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