Oxidation Resistance
Comparative Oxidation Resistance in Flowing Air
| Material |
1600°F (871°C) |
1800°F (982°C) |
| Average Metal Loss |
Average Metal Affected |
Average Metal Loss |
Average Metal Affected |
| Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
| HR-224® |
0 |
0 |
0.2 |
5 |
0 |
0 |
0.3 |
8 |
| 214® |
0 |
0 |
0.3 |
8 |
0 |
0 |
0.5 |
13 |
| 230® |
0 |
0 |
0.9 |
23 |
0.2 |
5 |
1.6 |
41 |
| 625 |
0.1 |
3 |
0.6 |
15 |
0.2 |
5 |
1.9 |
48 |
| X |
0.1 |
3 |
1 |
25 |
0.3 |
8 |
1.9 |
48 |
| HR-120® |
0.1 |
3 |
1.1 |
28 |
0.3 |
8 |
2.0 |
51 |
| 601 |
- |
- |
- |
- |
0.4 |
10 |
1.7 |
43 |
| 800HT |
0.1 |
3 |
1 |
25 |
0.5 |
13 |
4.1 |
104 |
| 347 SS |
0.3 |
8 |
0.7 |
18 |
- |
- |
- |
- |
| 253 MA |
0.2 |
5 |
0.9 |
23 |
1.3 |
33 |
3.0 |
76 |
Flowing air at a velocity of 7.0 ft/min (213.4 cm/min) past the samples. Samples cycled to room temperature once per week.
Comparative Long-Term Oxidation Resistance
| Material |
1800°F (982°C) |
| Average Metal Loss |
Average Metal Affected |
| Mils |
μm |
Mils |
μm |
| HR-224® |
0.1 |
3 |
0.1 |
3 |
| 214® |
0.1 |
3 |
0.5 |
13 |
| 230® |
0.1 |
3 |
2.7 |
69 |
| X |
0.2 |
5 |
2.8 |
71 |
| HR-120® |
0.5 |
13 |
3.3 |
84 |
| 625 |
2.6 |
66 |
8.6 |
218 |
Alloys exposed for 360 days (8,640 h) in flowing air, cycled once per month.
Comparative Oxidation Resistance in Water Vapor
| Material |
1400°F (760°C) |
1600°F (871°C) |
| Average Metal Loss |
Average Metal Affected |
Average Metal Loss |
Average Metal Affected |
| Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
| HR-224® |
0.05 |
1 |
0.25 |
7 |
0.06 |
2 |
0.26 |
7 |
| 214® |
0.02 |
1 |
0.22 |
7 |
0.05 |
1 |
0.35 |
9 |
| 230® |
0.09 |
2 |
1.19 |
30 |
0.21 |
5 |
1.91 |
49 |
| HR-120® |
0.12 |
3 |
0.72 |
18 |
0.26 |
7 |
2.06 |
52 |
Amount of metal affected for high‐temperature sheet (0.125”) alloys exposed for 8640h (cycled monthly) in air + 10%H2O
Comparative Cyclic Oxidation
| Material |
1400°F (760°C) |
1600°F (871°C) |
1800°F (982°C) |
2000°F (1093°C) |
| Average Metal Loss |
Average Metal Affected |
Average Metal Loss |
Average Metal Affected |
Average Metal Loss |
Average Metal Affected |
Average Metal Loss |
Average Metal Affected |
| Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
Mils |
μm |
| HR-224® |
< 0.1 |
0.6 |
0.1 |
1.9 |
0.1 |
3 |
0.3 |
8 |
0.1 |
3 |
0.3 |
8 |
0.2 |
5 |
0.8 |
20 |
| 214® |
< 0.1 |
0.3 |
0.1 |
1.6 |
0.1 |
3 |
0.1 |
3 |
0.1 |
3 |
0.5 |
13 |
0.1 |
6 |
0.4 |
10 |
| 230® |
< 0.1 |
0.8 |
0.1 |
2.7 |
0.1 |
3 |
0.7 |
18 |
0.2 |
5 |
1.1 |
28 |
0.9 |
23 |
4.1 |
104 |
| X |
- |
- |
- |
- |
0.2 |
5 |
1.0 |
25 |
0.3 |
8 |
1.6 |
41 |
10 |
254 |
12.1 |
307 |
| 601 |
- |
- |
- |
- |
- |
- |
- |
- |
0.5 |
13 |
1.9 |
48 |
- |
- |
- |
- |
| 625 |
- |
- |
- |
- |
0.1 |
3 |
0.5 |
13 |
0.4 |
10 |
2.0 |
51 |
- |
- |
- |
- |
| HR-120® |
< 0.1 |
1.2 |
0.2 |
6.0 |
0.2 |
5 |
0.9 |
23 |
0.4 |
10 |
2.0 |
51 |
18.5 |
470 |
20.6 |
523 |
| 600 |
- |
- |
- |
- |
0.1 |
3 |
0.8 |
20 |
0.5 |
13 |
2.2 |
56 |
- |
- |
- |
- |
| 800HT |
- |
- |
- |
- |
0.3 |
8 |
1.3 |
33 |
8 |
203 |
9.8 |
249 |
30.8 |
782 |
32.2 |
818 |
Amount of metal affected for alloys exposed to flowing air for 1000-h, cycled 1x/10h
Schematic Representation of Metallographic Technique used for Evaluating Oxidation
