| HAYNES® 242® alloy have very
good resistance to nitriding
environments. Tests were performed in flowing ammonia at
1800°F (980°C) for 168 hours.
Nitrogen absorption was determined
by chemical analysis
before and after exposure and
knowledge of the specimen area. |
|
Nitrogen Absorption |
| |
|
Alloy |
(mg/cm2) |
|
| HAYNES® 214 alloy |
0.3 |
| HAYNES 242® alloy |
0.7 |
| Alloy 600 |
0.9 |
| HAYNES® 230 alloy |
1.4 |
HASTELLOY® X alloy |
3.2 |
Alloy 800H |
4.0 |
| Type 316 Stainless Steel |
6.0 |
| Type 304 Stainless Steel |
7.3 |
| Type 310 Stainless Steel |
7.7 |
|
Resistance to Salt-Spray Corrosion |
HAYNES 242 alloy exhibits good
resistance to corrosion by
sodium-sulfate-containing sea
water environment at 1200°F
(650°C). Tests were performed by heating specimens to 300°F
(150°C), spraying with a simulated
sea water solution, cooling
and storing at room temperature
for a week, heating to 1200°F (650°C) for 20 hours in still air;
cooling to room temperature,
heating and spraying again at
300°F (150°C), and storing at
room temperature for a week. |
| |
Metal Loss |
Maximum Metal Affected |
| |
|
| Alloy |
Mils |
μm |
Mils |
μm |
|
| HASTELLOY® S alloy |
0.10 |
2.5 |
0.20 |
5.1 |
| HAYNES® 242® alloy |
0.15 |
3.8 |
0.30 |
7.6 |
| HASTELLOY B alloy |
0.20 |
5.1 |
0.30 |
7.6 |
| Alloy 909 |
0.40 |
10.2 |
1.20 |
30.5 |
|
Resistance to Hydrogen Embrittlement |
| 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.). |
|
|
|
|
Ratio of Notched Tensile Strength Hydrogen/Air |
| |
Hydrogen Pressure |
|
|
Alloy |
Psig |
MPa |
Kt |
|
| Waspaloy alloy |
7,000 |
48 |
6.3 |
.78 |
| Alloy 625 |
5,000 |
34 |
8.0 |
.76 |
| 242® alloy |
5,000 |
34 |
8.0 |
.74 |
| Alloy 718 |
10,000 |
69 |
8.0 |
.46 |
| Alloy R-41 |
10,000 |
69 |
8.0 |
.27 |
| Alloy X-750 |
7,000 |
48 |
6.3 |
.26 |
|
|