Corrosion of aluminized low-carbon steel exhaust system in vehicles equipped with three-way catalytic converters and development of a protective polymeric coating
| Autor: | Robert L. Goss, Haren S. Gandhi, C. R. Peters, Mohinder S. Chattha, James Perry |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Ammonium sulfate
Materials science Carbon steel General Chemical Engineering Metallurgy chemistry.chemical_element General Chemistry engineering.material Industrial and Manufacturing Engineering law.invention Corrosion chemistry.chemical_compound Coating chemistry Aluminium law Catalytic converter engineering Sulfur trioxide Sulfate |
| Zdroj: | Industrial & Engineering Chemistry Research. 29:1438-1442 |
| ISSN: | 1520-5045 0888-5885 |
| DOI: | 10.1021/ie00103a051 |
| Popis: | In automobiles equipped with three-way catalytic converters (TWCCs) with no secondary air, the cause of corrosion of the exhaust system has been identified to beammonium sulfate formation. Ammonia is formed over three-way catalysts (TWCs) under reducing conditions and reacts with sulfur trioxide, formed during lean conditions and stored on high surface area Al{sub 2}O{sub 3}, to form ammonium sulfate. The condensate solution of ammonium sulfate thus formed in the exhaust system reacts with the aluminized surface of the aluminized low-carbon steel, stripping it away and corroding the low carbon steel components. A coating composition has been developed from a new phenolic-type epoxy resin and diaminodiphenyl sulfone. This coating has a softening temperature higher than 200{degrees}C and is thermally stable in air up to 375{degrees}C. The coating adheres well to aluminized low-carbon steel and provides excellent corrosion protection during aqueous ammonium sulfate exposure in bench tests and during aging in a stimulated exhaust for 15000 simulated miles. Field testing of this polymer-coated exhaust system is planned on prototype vehicles. |
| Databáze: | OpenAIRE |
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