Extremely High-Rate, Uniform Dissolution of Alloy 22 in Anhydrous Organic Solutions at Room Temperature
| Autor: | Shawn P. Allwein, Christie Michael, Robert G. Kelly, Eric J. Schindelholz |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Materials science
020209 energy General Chemical Engineering Inorganic chemistry Alloy 02 engineering and technology General Chemistry engineering.material 021001 nanoscience & nanotechnology Electrochemistry Corrosion chemistry.chemical_compound chemistry 0202 electrical engineering electronic engineering information engineering Anhydrous engineering Slurry General Materials Science Steady state (chemistry) 0210 nano-technology Acetonitrile Dissolution |
| Zdroj: | CORROSION. 72:1292-1299 |
| ISSN: | 1938-159X 0010-9312 |
| Popis: | During routine pharmaceutical development and scale-up work, severe corrosion of a Hastelloy Alloy C-22 (Alloy 22) filter dryer was observed after single, short (several hour) contact with the product slurry at room temperature. Initial investigations showed that the presence of both 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and HCl was sufficient in an acetonitrile solution to cause rapid corrosion of Alloy 22. More detailed mass loss studies showed initial corrosion rates exceeding 25 mm/y that then decreased over several hours to steady state rates of 3 mm/y to 5 mm/y. The corrosion was highly uniform. Electrochemical measurements demonstrated that although Alloy 22 is spontaneously passive in acetonitrile solution, the presence of HCl leads to the development of a transpassive region. DDQ is a sufficiently strong oxidizer, particularly in acidic solutions, to polarize the Alloy 22 well into the transpassive region, leading to the observed high-corrosion rates. |
| Databáze: | OpenAIRE |
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