Notched room-temperature tensile tests performed in hydrogen and air reveal that 242® alloy is roughly equivalent to alloy 625 in resisting hydrogen embrittlement, and appears to be superior to many important materials. Tests were performed in MIL-P27201B grade hydrogen, with a crosshead speed of 0.005 in./min. (0.13 mm/min.).
Alloy
|
Hydrogen
Pressure |
- |
Ratio of Notched Tensile
Strength, Hydrogen/Air |
| psi |
MPa |
Kt |
| Waspaloy |
7,000 |
48 |
6.3 |
.78 |
| 625 |
5,000 |
34 |
8.0 |
.76 |
| 242® |
5,000 |
34 |
8.0 |
.74 |
| 718 |
10,000 |
69 |
8.0 |
.46 |
| R-41 |
10,000 |
69 |
8.0 |
.27 |
| X-750 |
7,000 |
48 |
6.3 |
.26 |