Hastelloy C-22 is a versatile nickel-chromium-molybdenum-tungsten alloy renowned for its exceptional resistance to a wide range of corrosive environments, including both oxidizing and reducing conditions. This alloy offers superb resistance to pitting, crevice corrosion, and stress corrosion cracking in harsh chemical environments containing chlorides, sulfuric acid, phosphoric acid, and other aggressive chemicals.
Its composition includes nickel, chromium, molybdenum, tungsten, and trace amounts of other elements. Hastelloy C-22 is commonly used in various applications across chemical processing, pollution control, pulp and paper, and pharmaceutical industries. Its properties make it well-suited for use in reactors, heat exchangers, scrubbers, and other equipment where corrosion resistance and reliability are paramount.
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| Physical Property | Imperial Units | Metric Units | ||
| Density | RT | 0.314 lb/in3 | RT | 8.69 g/cm3 |
| Melting Range | 2475-2550°F | — | 1357-1399°C | — |
| Electrical Resistivity | RT | 44.9 μ0hm.in | RT | 1.14 μ0hm.m |
| 200°F | 48.0 μ0hm.in | 100°C | 1.23 μ0hm.m | |
| 400°F | 48.8 μ0hm.in | 200°C | 1.24 μ0hm.m | |
| 600°F | 49.3 μ0hm.in | 300°C | 1.25 μ0hm.m | |
| 800°F | 49.7 μ0hm.in | 400°C | 1.26 μ0hm.m | |
| 1000°F | 50.1 μ0hm.in | 500°C | 1.27 μ0hm.m | |
| — | — | 600°C | 1.28 μ0hm.m | |
| Thermal Conductivity | RT | 69 btu.in/h.ft2.°F | RT | 10.1 W/m.°C |
| 200°F | 76 btu.in/h.ft2.°F | 100°C | 11.1 W/m.°C | |
| 400°F | 94 btu.in/h.ft2.°F | 200°C | 13.4 W/m.°C | |
| 600°F | 110 btu.in/h.ft2.°F | 300°C | 15.5 W/m.°C | |
| 800°F | 125 btu.in/h.ft2.°F | 400°C | 17.5 W/m.°C | |
| 1000°F | 139 btu.in/h.ft2.°F | 500°C | 19.5 W/m.°C | |
| — | — | 600°C | 21.3 W/m.°C | |
| Thermal Diffusivity | RT | 0.004 in2/s | RT | 0.027 cm2/s |
| 200°F | 0.005 in2/s | 100°C | 0.030 cm2/s | |
| 400°F | 0.005 in2/s | 200°C | 0.035 cm2/s | |
| 600°F | 0.006 in2/s | 300°C | 0.039 cm2/s | |
| 800°F | 0.007 in2/s | 400°C | 0.042 cm2/s | |
| 1000°F | 0.007 in2/s | 500°C | 0.046 cm2/s | |
| — | — | 600°C | 0.048 cm2/s | |
| Mean Coefficient of Thermal Expansion | 75-200°F | 6.9 μin/in. °F | 24-100°C | 12.4 μm/m.°C |
| 75-400°F | 6.9 μin/in. °F | 24-200°C | 12.4 μm/m.°C | |
| 75-600°F | 7.0 μin/in. °F | 24-300°C | 12.6 μm/m.°C | |
| 75-800°F | 7.4 μin/in. °F | 24-400°C | 13.1 μm/m.°C | |
| 75-1000°F | 7.7 μin/in. °F | 24-500°C | 13.7 μm/m.°C | |
| 75-1200°F | 8.1 μin/in. °F | 24-600°C | 14.3 μm/m.°C | |
| 75-1400°F | 8.5 μin/in. °F | 24-700°C | 14.9 μm/m.°C | |
| 75-1600°F | 8.8 μin/in. °F | 24-800°C | 15.5 μm/m.°C | |
| 75-1800°F | 9.0 μin/in. °F | 24-900°C | 15.9 μm/m.°C | |
| Specific Heat | 100°F | 0.098 Btu/lb.°F | 50°C | 414 J/kg.°C |
| 200°F | 0.101 Btu/lb.°F | 100°C | 423 J/kg.°C | |
| 400°F | 0.106 Btu/lb.°F | 200°C | 444 J/kg.°C | |
| 600°F | 0.111 Btu/lb.°F | 300°C | 460 J/kg.°C | |
| 800°F | 0.114 Btu/lb.°F | 400°C | 476 J/kg.°C | |
| 1000°F | 0.118 Btu/lb.°F | 500°C | 485 J/kg.°C | |
| — | — | 600°C | 514 J/kg.°C | |
| Dynamic Modulus of Elasticity | RT | 29.9 x 106 psi | RT | 206 GPa |
| 200°F | 29.4 x 106 psi | 200°C | 197 GPa | |
| 400°F | 28.5 x 106 psi | 300°C | 191 GPa | |
| 600°F | 27.6 x 106 psi | 400°C | 185 GPa | |
| 800°F | 26.6 x 106 psi | 500°C | 179 GPa | |
| 1000°F | 25.7 x 106 psi | 600°C | 174 GPa | |
| 1200°F | 24.8 x 106 psi | 700°C | 168 GPa | |
| 1400°F | 23.6 x 106 psi | 800°C | 160 GPa | |
| 1600°F | 22.4 x 106 psi | 900°C | 152 GPa | |
| 1800°F | 21.1 x 106 psi | 1000°C | 144 GPa | |
| Melting Range | 2475 – 2550°F | — | 1357 – 1399 °C | — |
RT= Room Temperature
| Form | Thickness/ Bar Diameter | Test Temperature | 0.2% Offset Yield Strength | Ultimate Tensile Strength | Elongation | ||||
| in. | mm. | °F | °C | ksi | MPa | ksi | MPa | % | |
| Sheet | 0.028-0.125 | 0.7-3.2 | RT | RT | 59 | 407 | 116 | 800 | 57 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 200 | 93 | 54 | 372 | 110 | 758 | 58 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 400 | 204 | 44 | 303 | 102 | 703 | 57 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 600 | 316 | 42 | 286 | 98 | 676 | 62 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 800 | 427 | 41 | 283 | 95 | 655 | 67 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 1000 | 538 | 40 | 276 | 91 | 627 | 61 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 1200 | 649 | 36 | 248 | 85 | 586 | 65 |
| Sheet | 0.028-0.125 | 0.7-3.2 | 1400 | 760 | 35 | 241 | 76 | 524 | 63 |
| Plate | 0.25-0.75 | 6.4-19.1 | RT | RT | 54 | 372 | 114 | 786 | 62 |
| Plate | 0.25-0.75 | 6.4-19.1 | 200 | 93 | 49 | 338 | 107 | 738 | 65 |
| Plate | 0.25-0.75 | 6.4-19.1 | 400 | 204 | 41 | 283 | 98 | 676 | 66 |
| Plate | 0.25-0.75 | 6.4-19.1 | 600 | 316 | 36 | 248 | 95 | 655 | 68 |
| Plate | 0.25-0.75 | 6.4-19.1 | 800 | 427 | 35 | 241 | 92 | 634 | 68 |
| Plate | 0.25-0.75 | 6.4-19.1 | 1000 | 538 | 34 | 234 | 88 | 607 | 67 |
| Plate | 0.25-0.75 | 6.4-19.1 | 1200 | 649 | 32 | 221 | 83 | 572 | 69 |
| Plate | 0.25-0.75 | 6.4-19.1 | 1400 | 760 | 31 | 214 | 76 | 524 | 68 |
| Bar | 0.5-2.0 | 12.7-50.8 | RT | RT | 52 | 359 | 111 | 765 | 70 |
| Bar | 0.5-2.0 | 12.7-50.8 | 200 | 93 | 45 | 310 | 105 | 724 | 73 |
| Bar | 0.5-2.0 | 12.7-50.8 | 400 | 204 | 38 | 262 | 96 | 662 | 74 |
| Bar | 0.5-2.0 | 12.7-50.8 | 600 | 316 | 34 | 234 | 92 | 634 | 79 |
| Bar | 0.5-2.0 | 12.7-50.8 | 800 | 427 | 31 | 214 | 89 | 614 | 79 |
| Bar | 0.5-2.0 | 12.7-50.8 | 1000 | 538 | 29 | 200 | 84 | 579 | 80 |
| Bar | 0.5-2.0 | 12.7-50.8 | 1200 | 649 | 28 | 193 | 80 | 552 | 80 |
| Bar | 0.5-2.0 | 12.7-50.8 | 1400 | 760 | 29 | 200 | 72 | 496 | 77 |
Values are averages from numerous tests
RT= Room Temperature
| Test Temperature | Impact Strength | ||
| °F | °C | ft-lbf | J |
| RT | RT | 419 | 568 |
| -320 | -196 | 346 | 469 |
Impact strengths were generated using Charpy V-notch samples, machined from mill annealed plate.
RT= Room Temperature
| Form | Hardness, HRBW | Typical ASTM Grain Size |
| Sheet | 88 | 3.5 – 5.5 |
| Plate | 88 | 0 – 4.5 |
| Bar | 84 | 1 – 3.5 |
All samples tested in solution-annealed condition.
HRBW = Hardness Rockwell “B”, Tungsten Indentor.
| Conc. Wt. % | 50°F | 75°F | 100°F | 125°F | 150°F | 175°F | 200°F | 225°F | Boiling |
| 10°C | 24°C | 38°C | 52°C | 66°C | 79°C | 93°C | 107°C | ||
| 2.5 | — | — | — | — | — | — | — | — | 0.02 |
| 5 | — | — | — | — | — | — | 0.01 | — | 0.76 |
| 7.5 | — | — | — | — | — | 0.01 | 0.45 | — | — |
| 10 | — | — | — | — | — | 0.01 | 1.50 | — | — |
| 15 | — | — | — | 0.01 | <0.01 | 0.88 | — | — | — |
| 20 | — | — | — | 0.01 | 0.46 | 0.8 | — | — | — |
| 25 | — | — | <0.01 | 0.20 | 0.29 | 0.58 | 0.97 | — | — |
| 30 | — | — | 0.11 | 0.23 | 0.29 | 0.59 | 1.12 | — | — |
| 40 | — | — | 0.07 | 0.13 | 0.21 | 0.34 | 0.66 | — | — |
All corrosion rates are in millimeters per year (mm/y); to convert to mils (thousandths of an inch) per year, divide by 0.0254.
Data are from Corrosion Laboratory Jobs 15-02, 27-02, and 37-02.
All tests were performed in reagent grade acids under laboratory conditions; field tests are encouraged prior to industrial use.
| Conc. Wt. % | 50°F | 75°F | 100°F | 125°F | 150°F | 175°F | 200°F | 225°F | Boiling |
| 10°C | 24°C | 38°C | 52°C | 66°C | 79°C | 93°C | 107°C | ||
| 1 | — | — | — | — | — | — | 0.01 | — | 0.06 |
| 1.5 | — | — | — | — | — | — | — | — | — |
| 2 | — | — | — | — | — | — | — | — | — |
| 2.5 | — | — | — | — | — | — | — | — | — |
| 3 | — | — | — | — | — | — | — | — | — |
| 3.5 | — | — | — | — | — | — | — | — | — |
| 4 | — | — | — | — | — | — | — | — | — |
| 4.5 | — | — | — | — | — | — | — | — | — |
| 5 | — | — | <0.01 | — | 0.44 | 1.44 | 3.02 | — | 8.99 |
| 7.5 | — | — | — | — | — | — | — | — | — |
| 10 | — | — | 0.01 | 0.28 | 0.98 | 1.99 | 4.39 | — | 11.68 |
| 15 | — | — | — | — | 0.98 | 1.91 | — | — | 11.02 |
| 20 | — | — | 0.20 | 0.32 | 0.90 | 1.72 | 3.38 | — | 9.73 |
All corrosion rates are in millimeters per year (mm/y); to convert to mils (thousandths of an inch) per year, divide by 0.0254. Data are from Corrosion Laboratory Jobs 442-82 and 176-83. All tests were performed in reagent grade acids under laboratory conditions; field tests are encouraged prior to industrial use.
| Conc. Wt. % | 50°F | 75°F | 100°F | 125°F | 150°F | 175°F | 200°F | 225°F | Boiling |
| 10°C | 24°C | 38°C | 52°C | 66°C | 79°C | 93°C | 107°C | ||
| 10 | — | — | — | — | <0.01 | — | 0.01 | — | 0.01 |
| 20 | — | — | — | — | 0.01 | — | 0.02 | — | 0.06 |
| 30 | — | — | — | — | 0.01 | — | 0.02 | — | 0.13 |
| 40 | — | — | — | — | 0.02 | 0.03 | 0.09 | — | 0.26 |
| 50 | — | — | — | — | — | 0.05 | 0.14 | 0.33 | 0.59 |
| 60 | — | — | — | — | 0.06 | 0.08 | 0.19 | 0.57 | 1.09 |
| 70 | — | — | — | — | 0.05 | 0.11 | 0.33 | 0.71 | 2.53 |
All corrosion rates are in millimeters per year (mm/y); to convert to mils (thousandths of an inch) per year, divide by 0.0254. Data are from Corrosion Laboratory Jobs 443-82 and 47-04. All tests were performed in reagent grade acids under laboratory conditions; field tests are encouraged prior to industrial use.
| Conc. Wt. % | 50°F | 75°F | 100°F | 125°F | 150°F | 175°F | 200°F | 225°F | Boiling |
| 10°C | 24°C | 38°C | 52°C | 66°C | 79°C | 93°C | 107°C | ||
| 50 | — | — | — | — | — | — | — | — | 0.07 |
| 60 | — | — | — | — | 0.08 | — | — | — | 0.16 |
| 65 | — | — | — | — | — | — | — | — | — |
| 70 | — | — | — | — | 0.07 | 0.13 | — | — | 0.23 |
| 75 | — | — | — | — | 0.05 | 0.12 | — | — | 0.19 |
| 80 | — | — | — | — | 0.06 | 0.12 | 0.16 | — | 0.25 |
| 85 | — | — | — | — | 0.07 | 0.12 | 0.20 | — | 0.66 |
All corrosion rates are in millimeters per year (mm/y); to convert to mils (thousandths of an inch) per year, divide by 0.0254. Data are from Corrosion Laboratory Jobs 443-82 and 47-04. All tests were performed in reagent grade acids under laboratory conditions; field tests are encouraged prior to industrial use.
| Conc. Wt. % | 75°F | 100°F | 125°F | 150°F | 175°F | 200°F | 225°F | 250°F | 275°F | Boiling |
| 24°C | 38°C | 52°C | 66°C | 79°C | 93°C | 107°C | 121°C | 135°C | ||
| 1 | — | — | — | — | — | — | — | — | — | — |
| 2 | — | — | — | — | — | 0.01 | — | — | — | 0.13 |
| 3 | — | — | — | — | — | — | — | — | — | — |
| 4 | — | — | — | — | — | — | — | — | — | — |
| 5 | — | — | — | <0.01 | 0.01 | 0.03 | — | — | — | 0.23 |
| 10 | — | — | — | — | 0.02 | 0.04 | — | — | — | 0.29 |
| 20 | — | — | — | 0.01 | 0.03 | 0.28 | — | — | — | 0.83 |
| 30 | — | — | — | 0.01 | 0.09 | 0.68 | — | — | — | 1.89 |
| 40 | — | — | 0.01 | 0.01 | 0.31 | 0.87 | — | — | — | 3.99 |
| 50 | — | — | — | 0.02 | 0.40 | 0.77 | 2.18 | — | — | 9.98 |
| 60 | — | — | 0.01 | — | 0.67 | 0.95 | 2.69 | 7.62 | — | — |
| 70 | — | — | — | 0.28 | 0.56 | 0.94 | 3.07 | 14.94 | — | — |
| 80 | — | — | 0.09 | — | 1.44 | 2.16 | 3.68 | 3.58 | — | — |
| 90 | — | — | — | 0.34 | 0.89 | 1.80 | 6.27 | 4.24 | — | — |
| 96 | — | — | — | 0.10 | — | 1.10 | — | — | — | — |
All corrosion rates are in millimeters per year (mm/y); to convert to mils (thousandths of an inch) per year, divide by 0.0254. Data are from Corrosion Laboratory Jobs 319-82, 445-82, and 19-14. All tests were performed in reagent grade acids under laboratory conditions; field tests are encouraged prior to industrial use.
| Chemical | Concentration | 100°F | 125°F | 150°F | 175°F | 200°F | Boiling |
| wt. % | 38°C | 52°C | 66°C | 79°C | 93°C | ||
| Acetic Acid | 99 | — | — | — | — | — | 0 |
| Formic Acid | 88 | — | — | — | — | — | <0.01 |
| Hydrobromic Acid |
2.5 | — | — | — | — | — | 0.02 |
| 5 | — | — | — | — | — | 0.76 | |
| 7.5 | — | — | — | 0.01 | — | — | |
| 10 | — | — | — | 0.01 | — | — | |
| 15 | — | 0.01 | <0.01 | 0.88 | — | — | |
| 20 | — | 0.01 | 0.46 | 0.80 | — | — | |
| 25 | <0.01 | 0.20 | 0.29 | 0.58 | — | — | |
| 30 | 0.11 | 0.23 | 0.29 | 0.59 | — | — | |
| 40 | 0.07 | 0.13 | 0.21 | 0.34 | — | — | |
| Hydrochloric Acid |
1 | — | — | — | — | 0.01 | 0.06 |
| 5 | <0.01 | — | 0.44 | — | — | — | |
| 7.5 | — | — | — | — | — | — | |
| 10 | 0.01 | 0.28 | 0.98 | — | — | — | |
| 15 | — | — | — | — | — | — | |
| 20 | 0.20 | 0.32 | 0.90 | — | — | — | |
| Hydrofluoric Acid* |
5 | 0.04 | 0.15 | 0.47 | 0.58 | — | — |
| 10 | 0.09 | 0.33 | 0.64 | 0.78 | — | — | |
| 20 | 0.22 | 0.53 | 0.95 | 1.65 | — | — | |
| Nitric Acid |
10 | — | — | <0.01 | — | 0.01 | 0.01 |
| 20 | — | — | 0.01 | — | 0.02 | 0.06 | |
| 30 | — | — | 0.01 | — | 0.0.2 | 0.13 | |
| 40 | — | — | 0.02 | — | 0.09 | 0.26 | |
| 50 | — | — | — | — | 0.14 | 0.59 | |
| 60 | — | — | 0.06 | — | 0.19 | 1.09 | |
| 65 | — | — | — | — | — | — | |
| 70 | — | — | 0.05 | — | 0.33 | 2.53 | |
| Phosphoric Acid |
50 | — | — | — | — | — | 0.07 |
| 60 | — | — | — | — | — | 0.16 | |
| 70 | — | — | — | — | — | 0.23 | |
| 75 | — | — | — | — | — | 0.19 | |
| 80 | — | — | — | — | — | 0.25 | |
| 85 | — | — | — | — | — | 0.66 | |
| Sulfuric Acid |
10 | — | — | — | 0.02 | 0.04 | 0.29 |
| 20 | — | — | 0.01 | 0.03 | 0.28 | 0.83 | |
| 30 | — | — | 0.01 | 0.09 | 0.68 | — | |
| 40 | — | — | 0.01 | 0.31 | 0.87 | — | |
| 50 | — | — | 0.02 | 0.40 | 0.77 | — | |
| 60 | — | — | — | 0.67 | 0.95 | — | |
| 70 | — | — | 0.28 | 0.56 | 0.94 | — | |
| 80 | — | — | — | 1.44 | 2.16 | — | |
| 90 | — | — | 0.34 | 0.89 | 1.80 | — | |
| 96 | — | — | 0.10 | — | 1.10 | — |
*Hydrofluoric acid can also induce internal attack of nickel alloys; these values represent only external attack.
| Alloy | Critical Pitting Temperature in Acidified 6% FeCl3 | Critical Crevice Temperature in Acidified 6% FeCl3 | ||
| °F | °C | °F | °C | |
| 316L | 59 | 15 | 32 | 0 |
| 254SMO | 140 | 60 | 86 | 30 |
| 625 | 212 | 100 | 104 | 40 |
| C-276 | >302 | >150 | 131 | 55 |
| C-22® | >302 | >150 | 176 | 80 |
| Alloy | Time to Cracking |
| 316L | 2 h |
| 254SMO | 24 h |
| 625 | No Cracking in 1,008 h |
| C-276 | No Cracking in 1,008 h |
| C-22® | No Cracking in 1,008 h |
| Alloy | Quiescent | Flowing | ||
| No. of Sites Attacked | Maximum Depth of Attack, mm | No. of Sites Attacked | Maximum Depth of Attack, mm | |
| 316L | A:2, B:2 | A:1.33, B:2.27 | A:2, B:2 | A:0.48, B:0.15 |
| 254SMO | A:2, B:2 | A:0.76, B:1.73 | A:2, B:2 | A:0.01, B:<0.01 |
| 625 | A:1, B:2 | A:0.18, B:0.04 | A:2, B:2 | A:<0.01, B:<0.01 |
| C-276 | A:1, B:1 | A:0.10, B:0.13 | A:0, B:0 | A:0, B:0 |
| C-22® | A:0, B:0 | A:0, B:0 | A:0, B:0 | A:0, B:0 |
Data was generated as part of a U.S. Navy study at the LaQue Laboratories in Wrightsville Beach, North Carolina (and published by D.M. Aylor et al, Paper No. 329, CORROSION 99, NACE International, 1999).
| Chemical | Concentration | Temperature | Corrosion Rate | ||||
| wt. % | °F | °C | Weld Metal | Wrought Base Metal | |||
| mpy | mm/y | mpy | mm/y | ||||
| H2SO4 | 30 | 150 | 66 | 0.6 | 0.02 | 0.4 | 0.01 |
| H2SO4 | 50 | 150 | 66 | 9.3 | 0.24 | 0.8 | 0.02 |
| H2SO4 | 70 | 150 | 66 | 10.3 | 0.26 | 11 | 0.28 |
| H2SO4 | 90 | 150 | 66 | 18.5 | 0.47 | 13.4 | 0.34 |
| HCI | 5 | 100 | 38 | <0.1 | <0.01 | <0.1 | <0.01 |
| HCI | 10 | 100 | 38 | <0.1 | <0.01 | 0.4 | 0.01 |
| HCI | 15 | 100 | 38 | 11.1 | 0.28 | 9.4 | 0.24 |
| HCI | 20 | 100 | 38 | 10.2 | 0.26 | 7.9 | 0.20 |
