Research has shown that materials which have high molybdenum content and low chromium content are generally superior to other materials in resisting high-temperature corrosion in fluorine-containing environments. HAYNES® 242® alloy is in that category, and displays excellent resistance to both fluoride gas and fluoride salt environments.
Comparative Resistance to 70% HF at 1670°F (910°C) for 136 Hours
Alloy
|
Thickness Loss |
| mils |
mm |
| 242® |
12.6 |
0.3 |
| S |
15.8 |
0.4 |
| N |
15.8 |
0.4 |
| 625 |
47.2 |
1.2 |
| 230® |
70.9 |
1.8 |
| C-22® |
78.7 |
2.0 |
| 600 |
141.7 |
3.6 |
Comparative Resistance to KCl-KF-NaF Mixed Salts
Samples were exposed to a mixture of KCl-KF-NaF salts for a total of 40 hours in service. Temperature was cycled from 1290 to 1650°F (700-900°C) during the course of the exposure.