Corrosion and Its Mechanism of Al-10% Si Alloy-Coated Steel in Methanol Containing H[sub 2]O, NaCl, and HCOOH
| Autor: | Noboru Akao, Rie Umebayashi, Katsuhisa Sugimoto, Nobuyoshi Hara |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Renewable Energy
Sustainability and the Environment Metallurgy Alloy Oxide Electron microprobe Methoxide engineering.material Condensed Matter Physics Surfaces Coatings and Films Electronic Optical and Magnetic Materials Corrosion Metal chemistry.chemical_compound chemistry visual_art Materials Chemistry Electrochemistry engineering visual_art.visual_art_medium Methanol Nuclear chemistry Eutectic system |
| Zdroj: | Journal of The Electrochemical Society. 149:B75 |
| ISSN: | 0013-4651 |
| DOI: | 10.1149/1.1447943 |
| Popis: | Corrosion behavior and mechanism of Al-10% Si alloy-coated steel produced by a melt-dipping method have been investigated in methanol containing H 2 O, NaCl, and HCOOH as contaminants. Immersion corrosion tests were performed in deaerated or aerated methanol with and without 0.1-30% H 2 O, 0.1% NaCl, and 0.1% HCOOH, and ex situ surface analysis and observation were made using an electron probe microanalyzer, X-ray photoelectron spectroscopy, optical microscopy, and scanning electron microscopy. The corrosion rate of the coated steel was negligibly small in methanol containing 0.1-30% H 2 O. However, in methanol containing 0.1-30% H 2 O with 0.1% NaCI or 0.1% HCOOH, the corrosion rate increased sharply at 0.1% H 2 O. From the surface analysis and observation after the tests, the corrosion in methanol containing 0.1% H 2 O with 0.1% NaCI proceeds on Al components in dendrites and eutectic structures of the coating layer. Al components corrode forming methoxide while the Si components in eutectic structures remain as metallic Si. In methanol containing 1-30% H 2 O, the surface of the coating layer was covered by oxide films composed of SiO 2 -Al 2 O 3 -Al(OH) 3 , which prevents corrosion. |
| Databáze: | OpenAIRE |
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