Influence of prephosphating on painted electrogalvanized steel
| Autor: | O. R. Mattos, I. C. P. Margarit, F. J. Fabri-Miranda, G. Bustamante |
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| Rok vydání: | 2003 |
| Předmět: |
Hydraulic press
Materials science Scanning electron microscope General Chemical Engineering Organic Chemistry Metallurgy chemistry.chemical_element Forming processes Zinc Galvanization Surfaces Coatings and Films Corrosion law.invention symbols.namesake chemistry law Materials Chemistry symbols Deformation (engineering) Lubricant |
| Zdroj: | Progress in Organic Coatings. 46:84-90 |
| ISSN: | 0300-9440 |
| DOI: | 10.1016/s0300-9440(02)00214-x |
| Popis: | The role of phosphate layers as lubricant and painting adhesion promoters is well known. Nowadays, in the automotive industry phosphating treatments are used twice, before and after the forming process of car panels. The effects of a double phosphating on the anticorrosive performance of the whole material are not well established. The present study evaluates the corrosion behavior of electrogalvanized steel with and without a phosphating treatment before mechanical deformation (prephosphating) which simulates the forming process in automotive industries. The samples are formed in a hydraulic press, rephosphated and painted. The composition, weight and morphology of the zinc and phosphate layers are characterized by X-ray diffraction, plasma spectrometry, weight-loss measurements and scanning electron microscopy (SEM). The analysis is complemented with electrochemical impedance taken before and after the forming processes. Results suggest a beneficial role for prephosphating, which is confirmed by cyclic corrosion tests of painted samples. |
| Databáze: | OpenAIRE |
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