Oxidation Resistance

HAYNES® 230® alloy exhibits excellent resistance to both air and combustion gas oxidizing environments, and can be used for long-term continuous exposure at temperatures up to 2100°F (1150°C). For exposures of short duration, 230® alloy can be used at higher temperatures.

Schematic Representation of Metallographic Technique used for
Evaluating Oxidation Tests

Schematic Representation of Metallographic Technique used for Evaluating Oxidation Tests

Comparative Dynamic Oxidation 

Alloy 1600°F (870°C), 2000 h, 30-min cycles 1800°F (980°C), 1000 h, 30-min cycles 2000°F (1090°C), 500 h, 30-min cycles 2100°F (1150°C), 200 h, 30-min cycles
Metal Loss Average Metal Affected Metal Loss Average Metal Affected Metal Loss Average Metal Affected Metal Loss Average Metal Affected
mils µm mils µm mils µm mils µm mils µm mils µm mils µm mils µm
188 1.1 28 2.9 74 1.1 28 3.2 81 10.9 277 13.1 333 8 203 9.7 246
230® 0.9 23 3.9 99 2.8 71 5.6 142 7.1 180 9.9 251 6.4 163 13.1 333
617 2 51 7.8 198 2.4 61 5.7 145 13.3 338 20.9 531 13.8 351 15.3 389
625 1.2 30 2.2 56 3.7 94 6 152 - - Consumed - - - -
556® 1.5 38 3.9 99 4.1 104 6.7 170 9.9 251 12.1 307 11.5 292 14 356
X 1.7 43 5.3 135 4.3 109 7.3 185 11.6 295 14 356 13.9 353 15.9 404
HR-120® - - - - 6.3 160 8.3 211 - - - - - - - -
RA330 2.5 64 5 127 8.7 221 10.5 267 15.4 391 17.9 455 11.5 292 13 330
HR-160® - - - - 5.4 137 11.9 302 12.5 18.1 460 8.7 221 15.5 394
310SS 6 152 7.9 201 16 406 18.3 465 - - - - - - Consumed
800H 3.9 99 9.4 239 22.9 582 Through Thickness - - Consumed after 300 h - - Consumed

Burner rig oxidation tests were conducted by exposing samples of 3/8” x 2.5” x thickness (9mm x 64 mm x thickness), in a rotating holder to the products of combustion of 2 parts No. 1 and 1 part No. 2 fuel burned at a ratio of air to fuel of about 50:1. Gas velocity was about 0.3 mach. Samples were automatically removed from the gas stream every 30 minutes and fan-cooled to near ambient temperature and then reinserted into the flame tunnel.

Comparative Oxidation in Flowing Air 2100°F (1150°C) for 1008 Hours

Microstructures shown are for coupons exposed for 1008 hours at 2100°F (1150°C) in air flowing 7.0 feet/minute (2.1 m/minute) past the samples. Samples were descaled by cathodically charging the coupons while they were immersed in a molten salt solution. The black area shown at the top of each picture represents actual metal loss due to oxidation. The data clearly show HAYNES® 230® alloy to be superior to both INCONEL alloy 601 and alloy 800H, as well as the other heat-resistant materials listed in the table above. 

230 - Oxidation in Flowing Air 2100°F (1150°C) for 1008 Hours

230® alloy 
Average Metal Affected 
= 3.4 mils (86 µm)

 INCONEL alloy 601 - Oxidation in Flowing Air 2100°F (1150°C) for 1008 Hours

INCONEL alloy 601 
Average Metal Affected 
= 5.3 mils (135 µm)

Alloy 800H - Oxidation in Flowing Air 2100°F (1150°C) for 1008 Hours

Alloy 800H 
Average Metal Affected 
= 8.9 mils (226 µm)

Water Vapor Testing



Alloy
1008 hours @ 1600F Cycled 1x/week in air+10%H2O 1008 hours @ 1600F Cycled 1x/week in air+20%H2O 6 months @ 1400F Cycled 1x/week in air+10%H2O
Metal Loss Average Metal Affected Metal Loss Average Metal Affected Metal Loss Average Metal Affected
mils per side mm per side mils per side mm per side mils per side mm per side mils per side mm per side mils per side mm per side mils per side mm per side
230® 0.07 0.002 0.53 0.013 0.03 0.001 0.21 0.005 0.05 0.001 0.35 0.009
625 0.11 0.003 0.5 0.013 0.04 0.001 0.27 0.007 - - - -
X 0.03 0.001 0.5 0.013 0.04 0.001 0.3 0.008 - - - -
253MA 0.66 0.017 1.59 0.040 0.08 0.002 0.68 0.017 - - - -
800HT - - - - - - - - 0.12 0.003 0.82 0.021
347SS 0.86 0.022 1.48 0.038 0.18 0.005 0.18 0.005 0.46 0.012 1.26 0.032

Amount of metal affected for high‐temperature sheet (0.060 ‐ 0.125”) alloys exposed for 360 days (8,640 h) in flowing air.

Alloy 1600°F 1800°F 2000°F 2100°F
Metal Loss* Average Metal Affected Metal Loss* Average Metal Affected Metal Loss* Average Metal Affected Metal Loss* Average Metal Affected
mils μm mils μm mils μm mils μm mils μm mils μm mils μm mils μm
625 0.3 8 1.4 36 - - - - - - - - - - - -
230® 0.2 5 1.4 36 0.1 3 2.5 64 3.4 86 11 279 28.5 724 34.4 874
617 0.3 8 1.6 41 - - - - - - - - - - - -
HR‐120® 0.3 8 1.6 41 0.5 13 3.3 84 18.1 460 23.2 589 33.6 853 44 1118
25 0.3 8 1.7 43 - - - - - - - - - - - -
188 0.2 5 1.8 46 - - - - - - - - - - - -
556® 0.3 8 1.9 48 0.5 13 6.2 157 15 381 24.1 612 - - - -
X 0.3 8 2.2 56 0.2 5 2.8 71 17.1 434 26.2 665 51.5 1308 55.4 1407
800HT 0.4 10 2.9 74 - - - - - - - - - - - -
HR-160® - - - - 1.7 43 13.7 348 7.2 183 30.8 782 12 305 45.6 1158

*Metal loss was calculated from final and initial metal thicknesses; i.e. ML = (OMT – FMT) /2

Static Oxidation Comparison

Alloy Comparative Oxidation Resistance in Flowing Air, 1008 Hours*
1800°F (982°C) 2000°F (1093°C) 2100°F (1149°C) 2200°F (1204°C)
Metal Loss Average Metal Affected Metal Loss Average Metal Affected Metal Loss Average Metal Affected Metal Loss Average Metal Affected
mils μm mils μm mils μm mils μm mils μm mils μm mils μm mils μm
230® 0.2 5 1.5 38 0.5 13 3.3 84 1.2 30 4.4 112 4.7 119 8.3 211
188 0.1 3 1.1 28 0.5 13 3.7 94 8.6 218 10.7 272 5.2 132 48.2 1224
601 0.4 10 1.7 43 1.3 33 3.8 97 2.8 71 6.5 165 4.4 112 7.5 191
617 0.3 8 2 51 0.6 15 3.8 97 1 25 5.2 132 10.7 272 12.6 320
X 0.2 5 1.5 38 1.3 33 4.4 112 3.6 91 6.1 115 - - - -
800HT 0.5 13 4.1 104 7.6 193 11.6 295 12.4 315 15 381 - - - -
446 SS - - - - 13 330 14.4 366 - - >21.5 >546 - - - -
316 SS 12.3 312 14.2 361 - - >17.5 >445 - - >17.5 >445 - - - -

*Metal Loss + Average Internal Penetration.

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