Principal Features

Excellent High-Temperature Strength, Thermal Stability, and Environment Resistance

HAYNES® 230® (UNS N06230) alloy is a nickel-chromium-tungsten-molybdenum alloy that combines excellent high-temperature strength, outstanding resistance to oxidizing environments up to 2100°F (1149°C) for prolonged exposures, premier resistance to nitriding environments, and excellent long-term thermal stability. It is readily fabricated and formed, and is castable. Other attractive features include lower thermal expansion characteristics than most high-temperature alloys, and a pronounced resistance to grain coarsening with prolonged exposure to hightemperatures.

Easily Fabricated

HAYNES® 230® alloy has excellent forming and welding characteristics. It may be forged or otherwise hot-worked, providing it is held at 2150°F (1177°C) for a time sufficient to bring the entire piece to temperature. As a consequence of its good ductility, 230® alloy is also readily formed by cold-working. All hot- or cold-worked parts should be annealed and rapidly cooled in order to restore the best balance of properties. The alloy can be welded by a variety of techniques, including gas tungsten arc (GTAW), gas metal arc (GMAW), and resistance welding.

Heat Treatment

Wrought 230® alloy is furnished in the solution heat treated condition, unless otherwise specified. The alloy is solution heat-treated in the range of 2150 to 2275°F (1177 to 1246°C) and rapidly cooled or water-quenched for optimum properties.

Annealing at temperatures lower than the solution heat treating temperatures will produce some carbide precipitation in 230® alloy, which may marginally affect the alloy’s strength and ductility.

Castings

HAYNES® 230® alloy may be cast using traditional air-melt sand mold or vacuum-melt investment casting foundry practices. Silicon levels at the high end of the specification range are recommended for enhanced fluidity. Castings may be used in either the as-cast or solution-heat-treated condition depending upon property requirements.

Applications

HAYNES® 230® alloy combines properties which make it ideally suited for a wide variety of component applications in the aerospace and power industries. It is used for combustion cans, transition ducts, flame holders, thermocouple sheaths, and other important gas turbine components. In the chemical process industry, 230® alloy is used for catalyst grid supports in ammonia burners, high-strength thermocouple protection tubes, high-temperature heat exchangers, ducts, high-temperature bellows, and various other key process internals.

In the industrial heating industry, applications for 230 alloy include furnace retorts, chains and fixtures, burner flame shrouds, recuperator internals, dampers, nitriding furnace internals, heat-treating baskets, grates, trays, sparger tubes, thermocouple protection tubes, cyclone internals, and many more.

*Please contact our technical support team if you have technical questions about this alloy.

Nominal Composition

Weight %
Nickel 57 Balance
Chromium 22
Tungsten 14
Molybdenum 2
Iron 3 max.
Cobalt 5 max.
Manganese 0.5
Silicon 0.4
Niobium 0.5 max.
Aluminum 0.3
Titanium 0.1 max.
Carbon 0.1
Lanthanum 0.02
Boron 0.015 max.

Creep and Stress-rupture Strength

HAYNES® 230® alloy is a solid-solution-strengthened material which combines excellent high-temperature strength with good fabricability at room temperature. It is particularly effective for very long-term applications at temperatures of 1200°F (650°C) or more, and is capable of outlasting stainless steels and nickel alloys by as much as 100 to 1 depending upon the temperature. Alternatively, the higher strength of 230® alloy allows for the use of design section thicknesses as much as 75 percent thinner than lesser alloys with no loss in load-bearing capability.

Stress-Rupture Lives for Various Alloys at Fixed Test Conditions (Bar and Plate)*

Alloy Hours to Rupture
1400°F (760°C) 1600°F (871°C) 1800°F (982°C)
15.0 ksi (103 MPa) 4.1 ksi (31 Mpa) 2.0 ksi (14 Mpa)
230® 8,200 65,000 5,000
625 19,000 14,000 2,400
X 900 5,000 2,100
800H 130 1,200 920
INCONEL® 601 50 1,200 1,000
253 MA® 140 900 720
600 15 280 580
316 SS 100 240 130
RA330® 30 230 130
304 SS 10 100 72

*Based upon Larson-Miller extrapolation

Comparison of Stress to Produce 1% Creep in 1000 Hours (Sheet)

230® Sheet, Solution Annealed

Temperature Creep Approximate Initial Stress to Produce Specified Creep in
10 Hours 100 Hours 1,000 Hours 10,000 Hours
°F °C % ksi MPa ksi MPa ksi MPa ksi MPa
1200 649 0.5 31 214
1 35 241 24* 165*
R 51 352 36 248 28 193
1300† 704 0.5 29 200 21 145 14.5 100
1 33 228 23 159 17 114
R 47 324 34 234 26 179 20 134
1400 760 0.5 19.2 132 13.7 94 9.6 66 7.3 50
1 21 145 15.5 107 11.5 79 8.6 59
R 32 221 24.5 169 18.2 125 13.2* 91*
1500 816 0.5 14.2 98 10.3 71 7.5 52 5.4* 37*
1 15 103 11.2 77 8.6 59 6.5* 45*
R 23* 161* 17.5 121 12.5 86 8.4* 58*
1600 871 0.5 11.3 78 8.1 56 5.7 39 4.0 28
1 11.7 81 9.0 62 6.2 43 4.3 30
R 17.0 117 12.5 86 8.2 57 5.6* 39*
1700 927 0.5 7.7 53 5.5 38 3.8 26 2.4* 17*
1 8.8* 61* 6.2 43 4.2 29 2.7* 19*
R 12.0* 83* 8.0 55 5.1 35 3.2 22
1800 982 0.5 7.0 48 3.6 25 1.8 12 0.85 5.9
1 8.0 55 4.1 28 2.0 14 1.0 6.9
R 10.0 69 5.4 37 2.6 18 1.2* 8.3*
1900 1038 0.5 1.7 12 0.8 5.5
1 2.0 14 0.9 6.2
R 3.0* 21* 1.5 10
2000 1093 0.5
1 0.9 6.2
R

*Significant extrapolation
† Values obtained using Larson-Miller interpolation

230® Plate, Solution Annealed

Temperature Creep Approximate Initial Stress to Produce Specified Creep in
10 Hours 100 Hours 1,000 Hours 10,000 Hours
°F °C % ksi MPa ksi MPa ksi MPa ksi MPa
1200 649 0.5 35 241 23 159
1 39 269 26.5 183 17.5 121
R 75 517 56 386 41 283 29 200
1300 704 0.5 35 241 21.5 148 14.5 100
1 39 269 24.5 169 18 124 12.3* 85*
R 59 407 42 290 30 207 21 145
1400 760 0.5 19 131 13.5 93 10.0 69
1 23 159 15.9 110 11.5 79 9.0* 62*
R 37 255 27 186 20 138 14.2 98
1500 816 0.5 14.0 97 10.4 72 8.2 57 6.1 42
1 16.5 114 12.5 86 9.5 66 6.9 48
R 26 179 20 138 14.0 97 9.8 68
1600 871 0.5 10.3 71 7.6 52 5.6 39 4.0 28
1 11.7 81 9.0 62 6.2 43 4.3 30
R 20 138 13.7 94 9.5 66 6.2 43
1700 927 0.5 7.8 54 5.7 39 3.9 27 2.5 17
1 8.8 61 6.8 47 4.5 31 2.7 19
R 15.0 103 10.0 69 6.0 41 3.6 25
1800 982 0.5 5.8 40 3.5 24 1.8 12 0.90 6.2
1 6.3 43 4.0 28 2.1 14 1.1 7.6
R 9.4 65 6.0 41 3.2 22 1.7 12
1900 1038 0.5 4.0 28 2.0 14 0.90 6.2
1 4.4 30 2.2 15 1.0 6.9 0.50* 3.4*
R 7.0 48 3.7 26 1.8 12 1.0 6.9
2000 1093 0.5 1.9 13 0.80 5.5 0.35 2.4
1 2.3 16 1.0 6.9 0.47 3.2 0.20* 1.4*
R 4.2 29 2.1 14 1.0 6.9 0.55 3.8
2100 1149 0.5 0.80 5.5 0.03* 2.1*
1 1.0 6.9 0.43 3.0
R 2.3 16 1.2 8.3 0.60 4.1

*Significant extrapolation

Low Cycle Fatigue

HAYNES® 230® alloy exhibits excellent low cycle fatigue properties at elevated temperature. Results shown below are for strain-controlled tests run in the temperature range from 800 to 1800°F (425 to 980°C). Samples were machined from plate. Tests were run with fully reversed strain (R=-1) at a frequency of 20 cpm (0.33 Hz).

Comparative Low Cycle Fatigue Properties

The graph below compares the low cycle fatigue lives of a number of alloys tested at 800°F (427°C) in both the as-received and 1400°F (760°C)/1000 hour pre-exposed condition. Samples were machined from plate or bar, after exposure for exposed samples. Tests were again run with fully reversed strain (R=-1) at a frequency of 20 cpm (0.33 Hz). TSR=Total Strain Range.

800°F (425°C) LCF Life for Various Alloys

Compilation of axial LCF test results (R=-1, f=0.33 Hz)

Temperature
Δεtot/%
Ni, Cycles to Initiation
Nf, Cycles to Failure
°F °C
800 427 1.50 2230 2398
1.00 8480 8742
0.80 14,918 16,575
0.65 45,127 46,523
0.55 103,910 115,456
1000 538 1.50 1329 1540
1.25 1974 2368
1.00 3330 4413
0.80 7864 8734
0.70 8423 9876
0.60 38,696 40,604
0.56 73,014 74,132
0.53 -- 200,005*
0.50 -- 201,190*
1200 649 1.25 1022 1257
1.00 1852 2254
0.80 3431 4248
0.60 8962 11,058
0.50 82,275 85,563
0.45 -- 200,002*
0.40 -- 200,005*
1400 760 0.80 1896 2218
0.40 20,519 21,564
0.40 43,915 45,279
0.30 -- 203,327*
1400 760 1.00 870 1097
1.00 827 990
0.70 3166 3622
0.50 8153 8490
0.40 51,285 57,819
0.40 68,451 75,470
0.38 95,165 96,844
0.37 91,879 97,612
0.35 -- 202,920*
0.30 -- 150,000*
1600 871 0.70 1279 1504
0.50 3939 4299
0.50 3176 3473
0.40 9712 10,837
0.40 9296 10,781
0.35 19,179 20,964
0.31 61,898 63,253
0.30 65,691 66,926
0.25 -- 200,770*
1800 982 0.60 818 1218
0.50 1506 2582
0.40 3520 4223
0.40 3070 4784
0.30 19,810 21,311
0.30 13,904 19,200
0.25 105,140 106,020
0.25 116,960 119,890

* Indicates a run-out.

Tensile Properties

Tensile Properties of 230® Sheet

Test Temperature 0.2%Yield Strength Ultimate Tensile Strength Elongation
°F °C ksi MPa ksi MPa %
70 21 60.4 417 121.4  837 47.3
1000 538 42.6 294 100.1 690 51.7
1200 649 42.2 291 96.6 666 56.9
1400 760 45.1 311 78.0 538 59.5
1600 871 34.2 236 44.6 308 74.2
1800 982 17.8 123 24.5 169 54.1
2000 1093 10.0 69 13.1 90 37.0

Tensile Properties of 230® Plate

Test Temperature 0.2% Yield Strength Ultimate Tensile Strength Elongation
70 21 55.5 383 123.6 852 46.0
1000 538 38.1 263 102.5 706 53.2
1200 649 38.7 267 98.2 677 53.0
1400 760 37.7 260 77.2 533 68.0
1600 871 33.9 234 45.1 311 94.0
1800 982 16.8 116 24.3 168 91.2
2000 1093 9.1 63 13.2 91 92.1

Comparison of Yield Strengths (Plate)

Thermal Stability

HAYNES® 230® alloy exhibits excellent retained ductility after long-term thermal exposure at intermediate temperatures. It does not exhibit sigma phase, mu phase, or other deleterious phase formation even after 16,000 hours of exposure at temperatures from 1200 to 1600°F (649 to 871°C). Principal phases precipitated from solid solution are all carbides.

This contrasts markedly with many other solid-solution-strengthened superalloys such as HAYNES® 188 alloy, HAYNES® 625 alloy, and HASTELLOY® X alloy. These alloys all precipitate deleterious phases, which impair both tensile ductility and impact strength.

other solid-solution-strengthened superalloys such as HAYNES® 188 alloy, HAYNES® 625 alloy, and HASTELLOY® X alloy. These alloys all precipitate deleterious phases, which impair both tensile ductility and impact strength.

Room-Temperature Properties after Thermal Exposure

Condition 0.2% Yield Strength Ultimate Tensile Strength Elongation R.A. Impact Strength
ksi ksi % % ft-lb
MA 58.4 123.1 50 47.2 54
+ 1200/8,000 hr 57.9 128.0 36.4 39 31.4
+ 1200/20,000 hr 57.6 128.4 34.8 37 28.9
+ 1200/30,000 hr 59.4 129.9 34 38.3
+ 1200/50,000 hr 61.2 131.7 33.9 36.9 25.8
+1400/8,000 hr 59.2 129.7 32 34.3 18.7
+1400/20,000 hr 55 126.9 31.2 31.6 18.8
+1400/30,000 hr 54.3 126.9 31.3 33.9
+1400/50,000 hr 55.2 127.7 32.2 32.5 20.7
+ 1600/8,000 hr 54.3 122.7 36.2 34.6 21.6
+ 1600/20,000 hr 50.1 121.6 34.4 31.1 19.5
+ 1600/30,000 hr 49.6 120.0 32.1 28.6
+ 1600/50,000 hr 50.4 116.7 25.2* 20.2 14.8

*BIGM; AGL Elong, which tends to be lower; Other data are 4D Elong.
R.A.= Reduction of Area

Retained Room Temperature Tensile Ductility after 8000 Hour Exposure at Temperature

Exposure Temperature 230 188 625 X
Room Temperature Tensile Elongation
°F % % %
1200 36.4 29.1 18 19
1400 32 10.8 13 19
1600 36.2 22.2 26 30

Resistance to Grain Growth

HAYNES® 230® alloy exhibits excellent resistance to grain growth at high temperatures. As a consequence of its very stable primary carbides, 230® alloy can be exposed at temperatures as high as 2200°F (1204°C) for up to 24 hours without exhibiting significant grain growth. Materials such as HAYNES® 188 alloy or HASTELLOY® X alloy exhibit greater grain growth under such conditions, as would most iron-, nickel-, or cobalt-base alloys and stainless steels.

Exposure Time Grain Size for Alloys Exposed at Temperature for Various Times*
HAYNES® 230® alloy HAYNES® 188 alloy HASTELLOY® X alloy
h 2150°F (1177°C)  2200°F (1204°C)  2150°F (1177°C) 2200°F (1204°C)  2150°F (1177°C) 2200°F (1204°C) 
0 4-4 1/2 4-4 1/2 4-5 4-5 3 1/2 3 1/2
1 4-5 4-4 1/2 2-5 2-4 3 1/2 0-1
4 4-4 1/2 4-4 1/2 3 1/2 3 3 1/2 0-1
24 4 4-4 1/2 0-2 1-3 00-4 0-1 1/2

*Plate Product in the fully annealed condition

Physical Properties

Physical Property British Units Metric Units
Density RT
0.324 lb/in3
RT
8.97 g/cm3
Melting Temperature 2400 - 2570°F 1301 - 1371°C
Electrical Resistivity RT 49.2 µohm-in RT 125.0 µohm-cm
200°F 49.5 µohm-in 100°C 125.8 µohm-cm
400°F 49.8 µohm-in 200°C 126.5 µohm-cm
600°F 50.2 µohm-in 300°C 127.3 µohm-cm
800°F 50.7 µohm-in 400°C 128.4 µohm-cm
1000°F 51.5 µohm-in 500°C 130.2 µohm-cm
1200°F 51.6 µohm-in 600°C 131.2 µohm-cm
1400°F 51.1 µohm-in 700°C 130.7 µohm-cm
1600°F 50.3 µohm-in 800°C 129.1 µohm-cm
1800°F 49.3 µohm-in 900°C 127.1 µohm-cm
- - 1000°C 125.0 µohm-cm
Thermal Diffusivity RT
3.8 x 10-3 in2/sec
RT
24.2 x 10-3 cm2/s
200°F
4.1 x 10-3 in2/sec
100°C
26.8 x 10-3 cm2/s
400°F
4.7 x 10-3 in2/sec
200°C
29.9 x 10-3 cm2/s
600°F
5.2 x 10-3 in2/sec
300°C
32.9 x 10-3 cm2/s
800°F
5.6 x 10-3 in2/sec
400°C
35.7 x 10-3 cm2/s
1000°F
6.1 x 10-3 in2/sec
500°C
38.5 x 10-3 cm2/s
1200°F
6.5 x 10-3 in2/sec
600°C
41.9 x 10-3 cm2/s
1400°F
6.7 x 10-3 in2/sec
700°C
43.0 x 10-3 cm2/s
1600°F
6.7 x 10-3 in2/sec
800°C
43.2 x 10-3 cm2/s
1800°F
7.3 x 10-3 in2/sec
900°C
44.4 x 10-3 cm2/s
- - 1000°C
48.2 x 10-3 cm2/s
Thermal Conductivity RT
62 Btu-in/ft2-hr-°F
RT 8.9 W/m-°C
200°F
71 Btu-in/ft2-hr-°F
100°C 10.4 W/m-°C
400°F
87 Btu-in/ft2-hr-°F
200°C 12.4 W/m-°C
600°F
102 Btu-in/ft2-hr-°F
300°C 14.4 W/m-°C
800°F
118 Btu-in/ft2-hr-°F
400°C 16.4 W/m-°C
1000°F
133 Btu-in/ft2-hr-°F
500°C 18.4 W/m-°C
1200°F
148 Btu-in/ft2-hr-°F
600°C 20.4 W/m-°C
1400°F
164 Btu-in/ft2-hr-°F
700°C 22.4 W/m-°C
1600°F
179 Btu-in/ft2-hr-°F
800°C 24.4 W/m-°C
1800°F
195 Btu-in/ft2-hr-°F
900°C 26.4 W/m-°C
- - 1000°C 28.4 W/m-°C
Specific Heat RT 0.095 Btu/lb-°F RT 397 J/kg·°C
200°F 0.099 Btu/lb-°F 100°C 419 J/kg·°C
400°F 0.104 Btu/lb-°F 200°C 435 J/kg·°C
600°F 0.108 Btu/lb-°F 300°C 448 J/kg·°C
800°F 0.112 Btu/lb-°F 400°C 465 J/kg·°C
1000°F 0.112 Btu/lb-°F 500°C 473 J/kg·°C
1200°F 0.134 Btu/lb-°F 600°C 486 J/kg·°C
1400°F 0.140 Btu/lb-°F 700°C 574 J/kg·°C
1600°F 0.145 Btu/lb-°F 800°C 595 J/kg·°C
1800°F 0.147 Btu/lb-°F 900°C 609 J/kg·°C
- - 1000°C 617 J/kg·°C
Mean Coefficient of Thermal Expansion 70 - 200°F 6.5 µin/in -°F 25 - 100°C
11.8 x 10-6 m/m·°C
70 - 400°F 6.9 µin/in -°F 25 - 200°C
12.4 x 10-6 m/m·°C
70 - 600°F 7.2 µin/in -°F 25 - 300°C
12.8 x 10-6 m/m·°C
70 - 800°F 7.4 µin/in -°F 25 - 400°C
13.2 x 10-6 m/m·°C
70 - 1000°F 7.6 µin/in -°F 25 - 500°C
13.6 x 10-6 m/m·°C
70 - 1200°F 8.0 µin/in -°F 25 - 600°C
14.1 x 10-6 m/m·°C
70 - 1400°F 8.3 µin/in -°F 25 - 700°C
14.7 x 10-6 m/m·°C
70 - 1600°F 8.6 µin/in -°F 25 - 800°C
15.2 x 10-6 m/m·°C
70 - 1800°F 8.9 µin/in -°F 25 - 900°C
15.7 x 10-6 m/m·°C
- - 25 - 1000°C
16.1 x 10-6 m/m·°C
Dynamic Modulus of Elasticity RT
30.3 x 106 psi
RT 209 GPa
200°F
30.1 x 106 psi
100°C 207 GPa
400°F
29.0 x 106 psi
200°C 200 GPa
600°F
27.8 x 106 psi
300°C 193 GPa
800°F
26.8 x 106 psi
400°C 186 GPa
1000°F
25.9 x 106 psi
500°C 181 GPa
1200°F
24.9 x 106 psi
600°C 175 GPa
1400°F
23.6 x 106 psi
700°C 168 GPa
1600°F
22.2 x 106 psi
800°C 159 GPa
1800°F
20.7 x 106 psi
900°C 150 GPa
2000ºF
19.1 x 106 psi
1000°C 141 GPa
Dynamic Shear Modulus RT
11.5 106 psi
RT 79 GPa
200°F
11.4 106 psi
100°C 79 GPa
400°F
11.0 106 psi
200°C 76 Gpa
600°F
10.5 x 106 psi
300°C 73 GPa
800°F
10.1 x 106 psi
400°C 70 GPa
1000°F
9.7 x 106 psi
500°C 67 GPa
1200°F
9.3 x 106 psi
600°C 64 GPa
1400°F
8.8 x 106 psi
700°C 61 GPa
1600°F
8.2 x 106 psi
800°C 57 GPa
1800°F
7.6 x 106 psi
900°C 52 GPa
2000°F
7.0 x 106 psi
1000°C 48 GPa
Poisson’s Ratio RT 0.31 RT 0.31
200°F 0.31 100°C 0.31
400°F 0.32 200°C 0.32
600°F 0.32 300°C 0.32
800°F 0.33 400°C 0.33
1000°F 0.33 500°C 0.33
1200°F 0.34 600°C 0.34
1400°F 0.34 700°C 0.34
1600°F 0.35 800°C 0.34
1800°F 0.36 900°C 0.35

*RT= Room Temperature

Thermal Expansion Characteristics

HAYNES® 230® alloy has relatively low thermal expansion characteristics compared to most high-strength superalloys, iron-nickel-chromium alloys, and austenitic stainless steels. This means lower thermal stresses in service for complex component fabrications, as well as tighter control over critical part dimensions and clearances.

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

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

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

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