HAYNES® 25 alloy
Principal Features
Excellent High-temperature Strength and Good Oxidation Resistance
HAYNES® 25 alloy (UNS R30605) is a cobalt-nickel-chromium-tungsten alloy that combines excellent high-temperature strength with good resistance to oxidizing environments up to 1800°F (980°C) for prolonged exposures, and excellent resistance to sulfidation. It can be fabricated and formed by conventional techniques, and has been used for cast components. Other attractive features include excellent resistance to metal galling.
Applications
HAYNES® 25 alloy combines properties which make it suitable for a number of component applications in the aerospace industry, including parts in established military and commercial gas turbine engines. In modern engines, it has largely been replaced by newer materials such as HAYNES® 188 alloy, and, most recently, 230® alloy, which possess improved properties. Another area of significant usage for HAYNES® 25 alloy is as a bearing material, for both balls and races.
*Please contact our technical support team if you have technical questions about this alloy.
Nominal Composition
Weight % | |
Cobalt | 51 Balance |
Nickel | 10 |
Iron | 3 max. |
Chromium | 20 |
Molybdenum | 1 max. |
Tungsten | 15 |
Manganese | 1.5 |
Silicon | 0.4 max. |
Carbon | 0.1 |
Creep and Stress-Rupture Strength
HAYNES® 25 alloy is a solid-solution-strengthened material which possesses excellent high-temperature strength. It is particularly effective for very long-term applications at temperatures of 1200 to 1800°F (650 to 980°C). It is stronger than nickel-base solid-solution-strengthened alloys, and is the strongest of the cobalt-base materials which still have good fabrication characteristics.
Solution-Annealed Sheet*
Temperature | Creep | Approximate Initial Stress to Produce Specified Creep in | ||||||
10 h | 100 h | 1,000 h | ||||||
°F | °C | % | ksi | MPa | ksi | MPa | ksi | MPa |
1200 | 649 | 0.5 | 62.0 | 427 | 47.5 | 328 | 33.5** | 231** |
1 | 71.0 | 490 | 54.0 | 372 | 39.0** | 269** | ||
R | 82.0 | 565 | 69.0 | 476 | 57.0 | 393 | ||
1300 | 704 | 0.5 | 43.0 | 296 | 30.0** | 207** | 21.0** | 145** |
1 | 49.5 | 341 | 35.0 | 241 | 23.2** | 160** | ||
R | 64.0 | 441 | 50.0 | 345 | 38.0 | 262 | ||
1400 | 760 | 0.5 | 28.0 | 193 | 19.5 | 134 | 14.8** | 102** |
1 | 32.0 | 221 | 21.5 | 148 | 16.2** | 112** | ||
R | 47.0** | 324** | 36.0 | 248 | 26.0 | 179 | ||
1500 | 816 | 0.5 | 18.5 | 128 | 14.0 | 97 | 10.2** | 70** |
1 | 20.2 | 139 | 15.5 | 107 | 12.3** | 85** | ||
R | 34.0** | 234** | 24.7 | 170 | 18.1 | 125 | ||
1600 | 871 | 0.5 | 13.7 | 94 | 9.9 | 68 | 6.9** | 48** |
1 | 15.2 | 105 | 12.0 | 83 | 8.9** | 61** | ||
R | 24.0** | 165** | 17.5 | 121 | 12.0 | 83 | ||
1700 | 927 | 0.5 | 9.7 | 67 | 6.8 | 47 | 4.5** | 31** |
1 | 12.0 | 83 | 8.8 | 61 | 5.6 | 39 | ||
R | 17.3** | 119** | 11.8 | 81 | 7.2 | 50 | ||
1800 | 982 | 0.5 | 6.8 | 47 | 4.5 | 31 | 2.6 | 18 |
1 | 8.8 | 61 | 5.6 | 39 | 3.0 | 21 | ||
R | 11.8** | 81** | 7.2 | 50 | 4.0 | 28 | ||
200 | 1093 | 0.5 | 2.8 | 19 | 1.3 | 9.0 | – | – |
1 | 3.3 | 23 | 1.4 | 9.7 | – | – | ||
R | 4.5 | 31 | 2.0 | 14 | – | – |
*Based on limited data
**Significant extrapolation
Solution-Annealed Bar
Temperature | Approximate Initial Stress to Produce Rupture in | ||||||
10 h | 100 h | 1,000 h | |||||
°F | °C | ksi | MPa | ksi | MPa | ksi | MPa |
1350 | 732 | 42.5 | 293 | 36.5 | 252 | 30.3 | 209 |
1400 | 760 | 39.2 | 270 | 31.5 | 217 | 24.1 | 166 |
1500 | 816 | 30.0 | 207 | 22.0 | 152 | 17.0 | 117 |
1600 | 871 | 23.0 | 159 | 16.5 | 114 | 12.0 | 83 |
1700 | 927 | 17.0 | 117 | 12.0 | 83 | 8.4 | 58 |
1800 | 982 | 11.5 | 79 | 7.5 | 52 | 5.0 | 34 |
Comparative Rupture Strength, Sheet
Tensile Properties
Solution-Annealed Plate
Test Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | |||
°F | °C | ksi | MPa | ksi | MPa | % |
RT | 68.7 | 474 | 145.1 | 1000 | 58.8 | |
1000 | 538 | 38.4 | 265 | 122.1 | 842 | 71.0 |
1200 | 649 | 33.4 | 230 | 123.5 | 852 | 64.3 |
1400 | 760 | 34.4 | 237 | 86.0 | 593 | 45.7 |
1600 | 871 | 32.0 | 221 | 48.3 | 333 | 104.7 |
1800 | 982 | 18.7 | 129 | 27.3 | 188 | 113.7 |
2000 | 1093 | 9.3 | 64 | 14.5 | 100 | 97.5 |
Solution-Annealed Sheet
Test Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | |||
°F | °C | ksi | MPa | ksi | MPa | % |
RT | 69.0 | 476 | 144.5 | 996 | 54.7 | |
1000 | 538 | 38.8 | 268 | 119.0 | 820 | 63.4 |
1200 | 649 | 37.2 | 256 | 119.3 | 823 | 54.2 |
1400 | 760 | 35.5 | 245 | 82.5 | 569 | 33.9 |
1600 | 871 | 33.5 | 231 | 46.3 | 319 | 97.8 |
1800 | 982 | 18.6 | 128 | 25.8 | 178 | 94.1 |
2000 | 1093 | 9.0 | 62 | 13.3 | 92 | 63.0 |
Hot-Rolled and 2250°F (1230°C) Solution-Annealed Bar*
Test Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | |||
°F | °C | ksi | MPa | ksi | MPa | % |
RT | 73 | 505 | 147 | 1015 | 60 | |
1000 | 538 | 43 | 295 | 113 | 780 | 63 |
1200 | 649 | 43 | 295 | 105 | 725 | 49 |
1400 | 760 | 41 | 285 | 90 | 620 | 29 |
1600 | 871 | 34 | 235 | 54 | 370 | 29 |
1800 | 982 | 19 | 130 | 28 | 195 | 41 |
*Limited data
RT = Room Temperature
*Elevated temperature tensile tests for bar were performed with a strain rate that is no longer standard. These results were from tests with a strain rate of 0.005 in./in./minute through yield and a crosshead speed of 0.5 in./minute for every inch of reduced test section from yield through failure. The current standard is to use a strain rate of 0.005 in./in./minute though yield and a crosshead speed of 0.05 in./minute for every inch of reduced test section from yield through failure.
Hardness and Grain Size
Form | Hardness, HRBW | Typical ASTM Grain Size |
Sheet | 97 | 3.5 – 5.5 |
Plate | 99 | 3.5 – 5 |
Bar | 98 | 3.5 – 5 |
All samples tested in solution-annealed condition
HRBW = Hardness Rockwell “B”, Tungsten Indentor.
Cold-Worked Properties
HAYNES® 25 alloy has excellent strength and hardness characteristics in the cold-worked condition. These high property levels are also evident at elevated temperature, making 25 alloy quite suitable for applications such as ball bearings and bearing races. A modest additional increase in hardness and strength can be achieved through aging of the cold-worked material.
Typical Tensile Properties, Cold-Worked Sheet*
Cold Reduction | Test Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | |||
% | °F | °C | ksi | MPa | ksi | MPa | % |
10 | 70 | 20 | 105 | 725 | 155 | 1070 | 41 |
100 | 540 | 78 | 540 | 114 | 785 | 48 | |
1200 | 650 | 80 | 550 | 115 | 795 | 37 | |
1400 | 760 | 67 | 460 | 87 | 600 | 8 | |
1600 | 870 | 47 | 325 | 62 | 425 | 13 | |
1800 | 980 | 27 | 185 | 39 | 270 | 15 | |
15 | 70 | 20 | 124 | 855 | 166 | 1145 | 30 |
1000 | 540 | 107 | 740 | 134 | 925 | 29 | |
1200 | 650 | 111 | 765 | 129 | 890 | 15 | |
1400 | 760 | 86 | 595 | 104 | 715 | 5 | |
1600 | 870 | 52 | 360 | 70 | 485 | 9 | |
1800 | 980 | 30 | 205 | 40 | 275 | 5 | |
20 | 70 | 20 | 141 | 970 | 183 | 1260 | 19 |
1000 | 540 | 133 | 915 | 156 | 1075 | 18 | |
1200 | 650 | 120 | 825 | 137 | 945 | 2 | |
1400 | 760 | 96 | 660 | 107 | 740 | 3 | |
1800 | 980 | 30 | 205 | 41 | 285 | 4 |
*Limited data for cold-rolled 0.050-inch (1.3 mm) thick sheet
Typical Tensile Properties, Cold-Worked and Aged Sheet*
Condition | Test Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | |||
% | °F | °C | ksi | MPa | ksi | MPa | % |
15% CW + Age A | 70 | 20 | 136 | 940 | 168 | 1160 | 31 |
1200 | 650 | 104 | 715 | 128 | 885 | 23 | |
20% CW + Age A | 70 | 20 | 152 | 1050 | 181 | 1250 | 17 |
1000 | 540 | 129 | 890 | 151 | 1040 | 19 | |
1200 | 650 | 128 | 885 | 144 | 995 | 8 | |
1400 | 760 | 97 | 670 | 108 | 745 | 2 | |
1600 | 870 | 59 | 405 | 74 | 510 | 6 | |
1800 | 980 | 33 | 230 | 43 | 295 | 5 | |
20% CW + Age B | 70 | 20 | 162 | 1115 | 191 | 1315 | 16 |
600 | 315 | 132 | 910 | 165 | 1140 | 28 | |
1000 | 540 | 124 | 855 | 149 | 1025 | 23 | |
1200 | 650 | 119 | 820 | 140 | 965 | 13 | |
1400 | 760 | 92 | 635 | 116 | 800 | 7 | |
1600 | 870 | 50 | 345 | 71 | 490 | 9 | |
1800 | 980 | 31 | 215 | 42 | 290 | 12 |
*Limited data for cold-rolled 0.050-inch (1.3 mm) thick sheet
Age A = 700°F (370°C)/1 hour
Age B = 1100°F (595°C)/2 hours
Typical Hardness at 70°F (20°C), Cold-Worked and Aged Sheet*
Cold-work | HRC, After Indicated Level of Cold Work and Subsequent Aging Treatment | ||
– | 900°F (480°C) | 1100°F (595°C) | |
% | None | 5 h | 5 h |
None | 24 | 25 | 25 |
5 | 31 | 33 | 31 |
10 | 37 | 39 | 39 |
15 | 40 | 44 | 43 |
20 | 44 | 44 | 47 |
*Limited data for cold-rolled 0.070-inch (1.8 mm) thick sheet
HRC = Hardness Rockwell “C”.
Impact Strength
Impact Strength Properties, Plate
Test Temperature | Typical Charpy V-Notch Impact Resistance | ||
°F | °C | ft.-lbs. | J |
-321 | -196 | 109 | 148 |
-216 | -138 | 134 | 182 |
-108 | -78 | 156 | 212 |
-20 | -29 | 179 | 243 |
RT | RT | 193 | 262 |
500 | 260 | 219 | 297 |
1000 | 540 | 201 | 273 |
1200 | 650 | 170 | 230 |
1400 | 760 | 143 | 194 |
1600 | 870 | 120 | 163 |
1800 | 980 | 106 | 144 |
Thermal Stability
When exposed for prolonged periods at intermediate temperatures, HAYNES® 25 alloy exhibits a loss of room temperature ductility in much the same fashion as some other solid-solution-strengthened superalloys, such as HASTELLOY® X alloy or alloy 625. This behavior occurs as a consequence of the precipitation of deleterious phases. In the case of a 25 alloy, the phase in question is CO2W laves phase. HAYNES® 188 alloy is significantly better in this regard than 25 alloy; however, for applications where thermal stability is important, 230® alloy is an even better selection.
Room-Temperature Properties of Sheet After Thermal Exposure*
Exposure Temperature | – | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | |||
°F | °C | h | ksi | MPa | ksi | MPa | % |
None | 0 | 66.8 | 460 | 135.0 | 930 | 48.7 | |
1200 | 650 | 500 | 70.3 | 485 | 123.6 | 850 | 39.2 |
1000 | 92.3 | 635 | 140.0 | 965 | 24.8 | ||
2500 | 95.1 | 655 | 130.7 | 900 | 12.0 | ||
1400 | 760 | 100 | 68.9 | 475 | 115.3 | 795 | 18.1 |
1600 | 870 | 100 | 72.1 | 495 | 113.6 | 785 | 9.1 |
500 | 77.3 | 535 | 126.1 | 870 | 3.5 | ||
1000 | 81.7 | 565 | 142.0 | 980 | 5.0 |
*Composite of multiple sheet lot tests
Physical Properties
Physical Property | British Units | Metric Units | ||
Density | RT |
0.327 lb/in3 |
RT |
9.07 g/cm3 |
Melting Range | 2425-2570°F | – | 1330-1410°C | – |
Electrical Resistivity | RT | 34.9 µohm-in | RT | 88.6 µohm-cm |
200°F | 35.9 µohm-in | 100°C | 91.8 µohm-cm | |
400°F | 37.6 µohm-in | 200°C | 95.6 µohm-cm | |
600°F | 38.5 µohm-in | 300°C | 97.6 µohm-cm | |
800°F | 39.1 µohm-in | 400°C | 98.5 µohm-cm | |
1000°F | 40.4 µohm-in | 500°C | 100.8 µohm-cm | |
1200°F | 41.8 µohm-in | 600°C | 104.3 µohm-cm | |
1400°F | 42.3 µohm-in | 700°C | 106.6 µohm-cm | |
1600°F | 40.6 µohm-in | 800°C | 107.8 µohm-cm | |
1800°F | 37.7 µohm-in | 900°C | 101.1 µohm-cm | |
– | – | 1000°C | 95.0 µohm-cm | |
Thermal Diffusivity | 70°F |
4.4 x 10-3in2/sec |
RT |
28.3 x 10-3cm2/sec |
125°F |
4.6 x 10-3in2/sec |
100°C |
30.1 x 10-3cm2/sec |
|
200°F |
4.8 x 10-3in2/sec |
200°C |
32.7 x 10-3cm2/sec |
|
400°F |
5.5 x 10-3in2/sec |
300°C |
35.6 x 10-3cm2/sec |
|
600°F |
6.0 x 10-3in2/sec |
400°C |
41.2 x 10-3cm2/sec |
|
800°F |
6.5 x 10-3in2/sec |
500°C |
43.5 x 10-3cm2/sec |
|
1000°F |
6.9 x 10-3in2/sec |
600°C |
45.5 x 10-3cm2/sec |
|
1200°F |
7.3 x 10-3in2/sec |
700°C |
47.6 x 10-3cm2/sec |
|
1400°F |
7.6 x 10-3in2/sec |
800°C |
49.6 x 10-3cm2/sec |
|
1600°F |
7.7 x 10-3in2/sec |
900°C |
48.7 x 10-3cm2/sec |
|
1800°F |
7.9 x 10-3in2/sec |
1000°C |
51.6 x 10-3cm2/sec |
|
2000°F |
8.3 x 10-3in2/sec |
– | – | |
Thermal Conductivity | 70°F |
72 Btu-in/ft2-h-°F |
25°C | 10.5 W/m-°C |
125°F |
77 Btu-in/ft2-h-°F |
100°C | 12.0 W/m-°C | |
200°F |
83 Btu-in/ft2-h-°F |
200°C | 14.0 W/m-°C | |
400°F |
99 Btu-in/ft2-h-°F |
300°C | 15.9 W/m-°C | |
600°F |
114 Btu-in/ft2-h-°F |
400°C | 17.7 W/m-°C | |
800°F |
127 Btu-in/ft2-h-°F |
500°C | 19.5 W/m-°C | |
1000°F |
140 Btu-in/ft2-h-°F |
600°C | 21.2 W/m-°C | |
1200°F |
152 Btu-in/ft2-h-°F |
700°C | 22.9 W/m-°C | |
1400°F |
165 Btu-in/ft2-h-°F |
800°C | 24.5 W/m-°C | |
1600°F |
178 Btu-in/ft2-h-°F |
900°C | 26.0 W/m-°C | |
1800°F |
191 Btu-in/ft2-h-°F |
1000°C | 27.5 W/m-°C | |
2000°F |
201 Btu-in/ft2-h-°F |
– | – | |
Specific Heat | 70°F | 0.096 Btu/lb.-°F | 25°C | 403 J/kg-°C |
125 °F | 0.098 Btu/lb.-°F | 100 °C | 424 J/kg-°C | |
200 °F | 0.101 Btu/lb.-°F | 200°C | 445 J/kg-°C | |
400 °F | 0.106 Btu/lb.-°F | 300°C | 455 J/kg-°C | |
600°F | 0.111 Btu/lb.-°F | 400°C | 462 J/kg-°C | |
800°F | 0.116 Btu/lb.-°F | 500°C | 495 J/kg-°C | |
1000°F | 0.119 Btu/lb.-°F | 600°C | 508 J/kg-°C | |
1200°F | 0.123 Btu/lb.-°F | 700°C | 582 J/kg-°C | |
1400°F | 0.128 Btu/lb.-°F | 800°C | 592 J/kg-°C | |
1600°F | 0.137 Btu/lb.-°F | 900°C | 596 J/kg-°C | |
180 °F | 0.143 Btu/lb.-°F | 1000°C | 598 J/kg-°C | |
2000°F | 0.142 Btu/lb.-°F | – | – | |
Mean Coefficient of Thermal Expansion | 70 - 200°F | 7.1 µin/in.-°F | 25 - 100°C | 12.8 µm/m-°C |
70 - 400°F | 7.3 µin/in.-°F | 25 - 200°C | 13.1 µm/m-°C | |
70 - 600°F | 7.5 µin/in.-°F | 25 - 300°C | 13.3 µm/m-°C | |
70 - 800°F | 7.7 µin/in.-°F | 25 - 400°C | 13.7 µm/m-°C | |
70 - 1000°F | 7.9 µin/in.-°F | 25 - 500°C | 14.0 µm/m-°C | |
70 - 1200°F | 8.2 µin/in.-°F | 25 - 600°C | 14.6 µm/m-°C | |
70 - 1400°F | 8.6 µin/in.-°F | 25 - 700°C | 15.1 µm/m-°C | |
70 - 1600°F | 8.9 µin/in.-°F | 25 - 800°C | 15.8 µm/m-°C | |
70 - 1800°F | 9.2 µin/in.-°F | 25 - 900°C | 16.2 µm/m-°C | |
70 - 2000°F | 9.5 µin/in.-°F | 25 - 1000°C | 16.7 µm/m-°C | |
Dynamic Modulus of Elasticity | RT |
32.6 x 106psi |
RT | 225 GPa |
200°F |
32.3 x 106psi |
100°C | 222 GPa | |
400°F |
31.0 x 106psi |
200°C | 214 GPa | |
600°F |
29.4 x 106psi |
300°C | 204 GPa | |
800°F |
28.3 x 106psi |
400°C | 197 GPa | |
1000°F |
26.9 x 106psi |
500°C | 188 GPa | |
1200°F |
25.8 x 106psi |
600°C | 181 GPa | |
1400°F |
24.3 x 106psi |
700°C | 174 GPa | |
1600°F |
22.8 x 106psi |
800°C | 163 GPa | |
1800°F |
21.4 x 106psi |
900°C | 154 GPa | |
– | – | 1000°C | 146 Gpa |
RT = Room Temperature
Wear Resistance
HAYNES® 25 alloy exhibits excellent resistance to metal galling and cavitation. Metal-to-Metal Galling results shown below were generated for standard matching material room-temperature pin on disc tests. Wear depths are given as a function of applied load. Cavitation tests were performed in accordance with ASTM G 32 water at 16°C, with a frequency of 20 kHz and an amplitude of 0.05 mm. The results of the wear tests indicate that 25 alloy is superior in galling and cavitation resistance to many materials, and is surpassed only by ULTIMET® alloy and HAYNES® 6B alloy. Both of these materials were specifically designed to have excellent wear resistance.
Alloy | Galling – Degree of Damage for Various Applied Loads | |||||
3,000 lbs. (1,365 kg) | 6,000 lbs. (2,725 kg) | 9,000 lbs. (4,090 kg) | ||||
– | mils | µm | mils | µm | mils | µm |
6B | 0.02 | 0.6 | 0.03 | 0.7 | 0.02 | 0.5 |
ULTIMET® | 0.11 | 2.9 | 0.11 | 2.7 | 0.08 | 2.0 |
25 | 0.23 | 5.9 | 0.17 | 4.2 | 0.17 | 4.2 |
188 | 1.54 | 39.2 | 3.83 | 97.3 | 3.65 | 92.6 |
HR-160® | 1.73 | 43.9 | 4.33 | 109.9 | 3.81 | 96.8 |
214® | 2.32 | 59.0 | 3.96 | 100.5 | 5.55 | 141.0 |
556® | 3.72 | 94.4 | 5.02 | 127.6 | 5.48 | 139.3 |
230® | 4.44 | 112.7 | 7.71 | 195.8 | 8.48 | 215.5 |
HR-120® | 6.15 | 156.2 | 7.05 | 179.0 | 10.01 | 254.2 |
Alloy | Cavitation – Mean Depth of Erosion | |||||||
24 h | 48 h | 72 h | 96 h | |||||
– | mils | µm | mils | µm | mils | µm | mils | µm |
ULTIMET® | 0.3 | 6.8 | 0.9 | 22.9 | 1.6 | 40.2 | 2.3 | 57.4 |
6B | 0.3 | 7.7 | 0.9 | 22.3 | 1.4 | 34.8 | 1.9 | 48.0 |
25 | 1.0 | 24.4 | 2.1 | 53.6 | 3.4 | 85.6 | 4.5 | 115.1 |
625 | 3.1 | 80.0 | 7.0 | 176.6 | 10.2 | 259.2 | Not tested | Not Tested |
556® | 3.3 | 83.8 | 6.9 | 175.8 | 9.6 | 244.3 | 11.4 | 289.8 |
230® | 3.8 | 97.6> | 7.5 | 190.1 | 9.9 | 251.8 | 11.9 | 301.7 |
Tested in accordance with ASTM G 32 water at 16ºC, with a frequency of 20 kHz and an amplitude of 0.05 mm
High-temperature Hardness
The following are results from standard vacuum furnace hot hardness tests. Values are given in originally measured DPH (Vickers) units and conversions to Rockwell C/BW scale in parentheses.
Vickers Diamond Pyramid Hardness (Rockwell C/BW Hardness) | ||||||||||
70°F (20°C) | 800°F (425°C) | 1000°F (540°C) | 1200°F (650°C) | 1400°F (760°C) | ||||||
Solution Treated | 251 | 22 HRC | 171 | 87 HRBW | 160 | 83 HRBW | 150 | 80 HRBW | 134 | 74 HRBW |
15% Cold-Work | 348 | 35 HRC | 254 | 23 HRC | 234 | 97 HRBW | 218 | 95 HRBW | – | – |
20% Cold-Work | 401 | 41 HRC | 318 | 32 HRC | 284 | 27 HRC | 268 | 25 HRC | – | – |
25% Cold-Work | 482 | 48 HRC | 318 | 32 HRC | 200 | 30 HRC | 286 | 28 HRC | – | – |
HRC = Hardness Rockwell “C”.
HRBW = Hardness Rockwell “B”, Tungsten Indentor.
Aqueous Corrosion Resistance
HAYNES® 25 alloy was not designed for resistance to corrosive aqueous media. Representative average corrosion data are given for comparison. For applications requiring corrosion resistance in aqueous environments, ULTIMET® alloy and HASTELLOY® corrosion-resistant alloys should be considered.
Alloy | Average Corrosion Rate, per year | |||||
1% HCl (Boiling) |
10% H2SO4 (Boiling) |
65% HNO3 (Boiling) |
||||
– | mils | mm | mils | mm | mils | mm |
ULTIMET® | <1 | <0.03 | 99 | 2.51 | 6 | 0.15 |
C-22® | 3 | 0.08 | 12 | 0.30 | 134 | 3.40 |
25 | 226 | 5.74 | 131 | 3.33 | 31 | 0.79 |
316L | 524 | 13.31 | 1868 | 47.45 | 9 | 0.23 |
Oxidation Resistance
HAYNES® 25 alloy exhibits good resistance to both air and combustion gas oxidizing environments, and can be used for long-term continuous exposure at temperatures up to 1800°F (980°C). For exposures of short duration, 25 alloy can be used at higher temperatures. Applications for which oxidation resistance is a serious consideration normally call for newer, more capable materials such as 230® alloy or HAYNES 188 alloy. This is particularly important at temperatures above 1800°F (980°C).
Comparative Burner Rig Oxidation Resistance
1000 Hour Exposure at 1800°F (980°C), 30 minute Cycles
Alloy | Metal Loss | Average Metal Affected | Maximum Metal Affected | |||
mils | μm | mils | μm | mils | μm | |
188 | 1.1 | 28 | 3.2 | 81 | 3.9 | 99 |
230® | 2.8 | 71 | 5.6 | 142 | 6.4 | 163 |
617 | 2.4 | 61 | 5.7 | 145 | 6.9 | 175 |
625 | 3.7 | 94 | 6.0 | 152 | 6.6 | 168 |
X | 4.3 | 109 | 7.3 | 185 | 8.0 | 203 |
5 | 7.8 | 198 | 9.8 | 249 | 10.3 | 262 |
310SS | 16.0 | 406 | 18.3 | 465 | 19.5 | 495 |
800H | 22.9 | 582 | Internal oxidation through thickness |
Oxidation Test Parameters
Burner rig oxidation tests were conducted by exposing samples 3/8 in. x 2.5 in. x thickness (9 mm x 64 mm x thickness), in a rotating holder, to products of combustion of No. 2 fuel oil 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 fancooled to near ambient temperature and then reinserted into the flame tunnel.
Comparative Burner Rig Oxidation Resistance at 2000°F (1095°C) for 500 Hours
Alloy | Average Metal Loss per Side | Maximum Metal Affected | ||
mils | μm | mils | μm | |
214® | 1.2 | 30.5 | 1.8 | 45.7 |
230® | 7.1 | 180.3 | 11.8 | 299.7 |
188 | 10.9 | 276.9 | 14.1 | 358.1 |
X | 11.6 | 294.6 | 15.1 | 383.5 |
25 | > 25* | >635* | – | – |
*25 mils (635 µm) in 165 hours
Comparative Oxidation Resistance in Flowing Air*
Alloy | 1800°F (980°C) | 2000°F (1095°C) | 2100°F (1150°C) | |||||||||
Average Metal Affected | Metal Loss | Average Metal Affected | Metal Loss | Average Metal Affected | Metal Loss | |||||||
mils | μm | mils | μm | mils | μm | mils | μm | mils | μm | mils | μm | |
188 | 1.1 | 28 | 0.1 | 3 | 3.7 | 94 | 0.5 | 13 | 10.7 | 272 | 8.6 | 218 |
230® | 1.5 | 38 | 0.2 | 5 | 3.3 | 84 | 0.5 | 13 | 4.4 | 112 | 1.2 | 30 |
25 | 2.0 | 51 | 0.3 | 8 | 10.2 | 259 | 9.2 | 234 | 10.7 | 272 | 8.2 | 208 |
X | 1.5 | 38 | 0.2 | 5 | 4.4 | 112 | 1.3 | 33 | 6.1 | 115 | 3.6 | 91 |
625 | 1.9 | 48 | 0.4 | 10 | 7.8 | 198 | 3.5 | 89 | 20.2 | 513 | 18.3 | 465 |
617 | 2.0 | 51 | 0.3 | 8 | 3.8 | 97 | 0.6 | 15 | 5.2 | 132 | 1 | 25 |
800HT | 4.1 | 104 | 0.5 | 13 | 11.6 | 295 | 7.6 | 193 | 15.0 | 381 | 11 | 279 |
*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.
**Average Metal Affected = Metal Loss + Average Internal Penetration
Sulfidation Resistance
Sulfidation Resistance at 1400°F (760°C)
HAYNES® 25 alloy has very good resistance to gaseous sulfidation environments encountered in various industrial applications. Tests were conducted at 1400°F (760°C) in a gas mixture consisting of AR – 5% H2 – 5% CO – 1% CO2 – 0.15% H2S, balance Ar. Coupons were exposed for 215 hours. This is a severe test, with equilibrium sulfur partial pressure of 10-6 to 10-7 and oxygen partial pressures less than that needed to produce protective chromium oxide scales.
Schematic Representation of Metallographic Technique Used for Evaluating Environmental Tests
Fabrication
HAYNES® 25 alloy has good forming and welding characteristics. It may be forged or otherwise hot-worked, providing that it is held at 2200°F (1205°C) for a time sufficient to bring the entire piece to temperature. The alloy has good ductility, and thus also may be formed by cold working. The alloy does work-harden very rapidly, however, so frequent intermediate annealing treatments will be needed for complex component forming operations. 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 both manual and automatic welding methods, including gas tungsten arc (GTAW), gas metal arc (GMAW), shielded metal arc, electron beam and resistance welding. It exhibits good restraint welding characteristics.
Heat Treatment
HAYNES® 25 alloy is furnished in the solution heat-treated condition, unless otherwise specified. The alloy is normally final solution heat-treated at 2150 to 2250°F (1175 to 1230°C) for a time commensurated with section thickness and rapidly cooled or water-quenched for optimal properties. Because annealing at temperatures less than the solution heat-treating temperature will produce some carbide precipitation in 25 alloy, which may affect the alloy’s properties, annealing during fabrication may be performed at lower temperatures, but a final, subsequent solution heat treatment is needed to produce optimum properties and structure.
Machining
For information on Machining, please refer to the machining section of Welding and Fabrication.
Effect of Cold Reduction Upon Room-Temperature Properties*
Cold Reduction | Subsequent Anneal | 0.2% Yield Strength | Ultimate Tensile Strength | Elongation | Hardness | ||
% | None | ksi | MPa | ksi | MPa | % | HRC |
0 | 68.4 | 470 | 144.0 | 995 | 58.5 | 24 | |
10 | 123.6 | 850 | 181.9 | 1255 | 37.1 | 36 | |
15 | 148.5 | 1025 | 178.2 | 1230 | 27.7 | 40 | |
20 | 150.9 | 1040 | 193.5 | 1335 | 18.2 | 42 | |
25 | 183.9 | 1270 | 232.5 | 1605 | 14.6 | 44 | |
10 | 1950°F (1065°C) for 5 min. | 97.9 | 675 | 163.0 | 1125 | 39.3 | 32 |
15 | 91.2 | 630 | 167.1 | 1150 | 43.8 | 30 | |
20 | 96.5 | 665 | 170.7 | 1175 | 40.8 | 32 | |
25 | 88.9 | 615 | 169.5 | 1170 | 44.3 | 32 | |
10 | 2050°F (1120°C) for 5 min. | 74.0 | 510 | 156.6 | 1080 | 53.4 | 27 |
15 | 78.6 | 540 | 161.2 | 1110 | 51.9 | 28 | |
20 | 82.0 | 565 | 164.8 | 1135 | 47.6 | 31 | |
25 | 82.9 | 570 | 165.6 | 1140 | 48.0 | 30 | |
10 | 2150°F (1117°C) for 5 min. | 66.9 | 460 | 148.1 | 1020 | 62.6 | 21 |
15 | 73.6 | 505 | 156.1 | 1075 | 55.4 | 26 | |
20 | 72.1 | 495 | 154.0 | 1060 | 59.3 | 26 | |
25 | 68.5 | 470 | 149.3 | 1030 | 61.7 | 25 |
*Based upon cold reductions taken upon 0.110-inch (2.8 mm) thick sheet. Duplicate tests.
HRC = Hardness Rockwell “C”.
Welding
HAYNES® 25 alloy is readily welded by Gas Tungsten Arc (GTAW), Gas Metal Arc (GMAW), Shielded Metal Arc (SMAW), electron bean welding, and resistance welding techniques. Its welding characteristics are similar to those of HAYNES® 188 alloy. Submerged Arc welding is not recommended, as this process is characterized by high heat input to the base metal and slow cooling of the weld. These factors can increase weld restraint and promote cracking.
Base Metal Preparation
The joint surface and adjacent area should be thoroughly cleaned before welding. All grease, oil, crayon marks, sulfur compounds, and other foreign matter should be removed. Contact with copper or copper-bearing materials in the joint area should be avoided. It is preferable, but not necessary, that the alloy be in the solution-annealed condition when welded.
Filler Metal Selection
Matching composition filler metal is recommended for joining alloy 25. For shielded metal arc welding, HAYNES® 25 alloy electrodes (AMS 5797) are suggested. For dissimilar joining of 25 alloy to nickel-, cobalt-, or iron- base materials, 25 alloy itself (AMS 5796), 230-W® filler wire(AMS 5839), HAYNES® 556® alloy (AMS 5831), HASTELLOY® S alloy (AMS 5838), or HASTELLOY® W alloy (AMS 5786) welding products are suggested, depending upon the particular case. Please click here or see the Haynes Welding SmartGuide for more information.
Preheating, Interpass Temperatures, and Postweld Heat Treatment
Preheat is not required. Preheat is generally specified as room temperature (typical shop conditions). Interpass temperature should be maintained below 200°F (93°C). Auxiliary cooling methods may be used between weld passes, as needed, providing that such methods do not introduce contaminants. Postweld heat treatment is not generally required for 25 alloy. For further information, please click here.
Welded Tensile – Room Temperature
Form | 0.2% Yield Strength | Ultimate Tensile Strength | Elongation | ||
ksi | MPa | ksi | MPa | % | |
Sheet | 69.0 | 476 | 144.5 | 996 | 54.7 |
Plate | 68.7 | 474 | 145.1 | 1000 | 58.8 |
Welded Transverse, GTAW | 72.4 | 499 | 134.2 | 925 | 36.5 |
All Weld Metal, SMAW | 88.6 | 611 | 141.0 | 972 | 31.5 |
Specifications and Codes
Specifications
HAYNES® 25 alloy (R30605) | |
Sheet, Plate & Strip | AMS 5537 |
Billet, Rod & Bar | AMS 5759MIL-C-24252D |
Coated Electrodes | AMS 5797 |
Bare Welding Rods & Wire | AMS 5796 |
Seamless Pipe & Tube | – |
Welded Pipe & Tube | – |
Fittings | – |
Forgings | AMS 5759 |
DIN | – |
Others | NACE MR0175ISO 15156 |
Codes
HAYNES® 25 alloy (R30605) | |
MMPDS | 6.4.1 |
Disclaimer
Haynes International makes all reasonable efforts to ensure the accuracy and correctness of the data displayed on this site but makes no representations or warranties as to the data’s accuracy, correctness or reliability. All data are for general information only and not for providing design advice. Alloy properties disclosed here are based on work conducted principally by Haynes International, Inc. and occasionally supplemented by information from the open literature and, as such, are indicative only of the results of such tests and should not be considered guaranteed maximums or minimums. It is the responsibility of the user to test specific alloys under actual service conditions to determine their suitability for a particular purpose.
For specific concentrations of elements present in a particular product and a discussion of the potential health affects thereof, refer to the Safety Data Sheets supplied by Haynes International, Inc. All trademarks are owned by Haynes International, Inc., unless otherwise indicated.