HASTELLOY C-2000 alloy is available in the form of plates, sheets, strips, billets, bars, wires, pipes, tubes, and covered electrodes. Typical chemical process industry (CPI) applications include reactors and heat exchangers.
Principal Features
HASTELLOY C-2000 alloy (UNS N06200) is unique among the versatile nickel-chromium-molybdenum materials in having a deliberate copper addition. This provides greatly enhanced resistance to sulfuric acid. It also has a high chromium content, to maximize its resistance to oxidizing chemicals and process streams contaminated with ferric ions and dissolved oxygen.
Like other nickel alloys, it is ductile, easy to form and weld, and possesses exceptional resistance to stress corrosion cracking in chloride-bearing solutions (a form of degradation to which the austenitic stainless steels are prone). It is able to withstand a wide range of oxidizing and non-oxidizing chemicals, and exhibits outstanding resistance to pitting and crevice attack in the presence of chlorides and other halides.
HASTELLOY C-2000 alloy is available in the form of plates, sheets, strips, billets, bars, wires, pipes, tubes, and covered electrodes. Typical chemical process industry (CPI) applications include reactors and heat exchangers.
Nominal Composition
| Weight % | |
| Nickel | 59 Balance |
| Cobalt | 2 max. |
| Chromium | 23 |
| Molybdenum | 16 |
| Copper | 1.6 |
| Iron | 3 max. |
| Manganese | 0.5 max. |
| Aluminum | 0.5 max. |
| Silicon | 0.08 max. |
| Carbon | 0.01 max. |
Resistance to Pitting and Crevice Corrosion
HASTELLOY C-2000 alloy exhibits high resistance to chloride-induced pitting and crevice attack, forms of corrosion to which the austenitic stainless steels are particularly prone. To assess the resistance of alloys to pitting and crevice attack, it is customary to measure their Critical Pitting Temperatures and Critical Crevice Temperatures in acidified 6 wt.% ferric chloride, in accordance with the procedures defined in ASTM Standard G 48. These values represent the lowest temperatures at which pitting and crevice attack are encountered in this solution, within 72 hours. For comparison, the values for 316L, 254SMO, 625, C-276, and C-2000 alloys are as follows. Note that C-2000 alloy exhibits higher resistance to crevice attack than even C-276 alloy.
| Alloy |
Critical Pitting Temperaturein Acidified 6% FeCl3
|
Critical Crevice Temperaturein 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-2000® | 293 | 145 | 176 | 80 |
Other chloride-bearing environments, notably Green Death (11.5% H2SO4 + 1.2% HCl + 1% FeCl3 + 1% CuCl2) and Yellow Death (4% NaCl + 0.1% Fe2(SO4)3 + 0.021M HCl), have been used to compare the resistance of various alloys to pitting and crevice attack (using tests of 24 hours duration). In Green Death, the lowest temperature at which pitting has been observed in C-2000 alloy is 100°C. In Yellow Death, C-2000 alloy has not exhibited pitting, even at the maximum test temperature (150°C).The Critical Crevice Temperature of C-2000 alloy in Yellow Death is 95°C.
Resistance to Stress Corrosion Cracking
One of the chief attributes of the nickel alloys is their resistance to chloride-induced stress corrosion cracking. A common solution for assessing the resistance of materials to this extremely destructive form of attack is boiling 45% magnesium chloride (ASTM Standard G 36), typically with stressed U-bend samples. As is evident from the following results, the three nickel alloys, C-276, C-2000 and 625, are much more resistant to this form of attack than the comparative, austenitic stainless steels. The tests were stopped after 1,008 hours (six weeks).
| 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-2000® | No Cracking in 1,008 h |
Resistance to Seawater Crevice Corrosion
Seawater is probably the most common aqueous salt solution. Not only is it encountered in marine transportation and offshore oil rigs, but it is also used as a coolant in coastal facilities. Listed are data 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). Crevice tests were performed in both still (quiescent) and flowing seawater, at 29°C, plus or minus 3°C. Two samples (A & B) of each alloy were tested in still water for 180 days, and likewise in flowing water. Each sample contained two possible crevice sites. The results indicate that C-2000 alloy is very resistant to crevice corrosion in seawater.
| Alloy | Quiescent | Flowing | ||
| No. of Sites Attacked | Maximum Depthof Attack, mm | No. of Sites Attacked | Maximum Depthof 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-2000 | A:0, B:0 | A:0, B:0 | A:0, B:0 | A:0, B:0 |
Corrosion Resistance of Welds
To assess the resistance of welds to corrosion, Haynes International has chosen to test all-weld-metal samples, taken from the quadrants of cruciform assemblies, created using multiple gas metal arc (MIG) weld passes. Predictably, the inhomogeneous nature of weld microstructures leads generally to higher corrosion rates (than with homogeneous, wrought products). Nevertheless, HASTELLOY C-2000 alloy exhibits excellent resistance to the key, inorganic acids, even in welded form, as shown in the following table:
| Chemical | Concentration | Temperature | Corrosion Rate | ||||
| wt.% | °F | °C | Weld Metal | Wrought Base Metal | |||
| mpy | mm/y | mpy | mm/y | ||||
|
H2SO4
|
30 | 150 | 66 | 0.2 | 0.01 | <0.1 | <0.01 |
|
H2SO4
|
50 | 150 | 66 | 0.3 | 0.01 | <0.1 | <0.01 |
|
H2SO4
|
70 | 150 | 66 | 2.4 | 0.06 | 0.2 | 0.01 |
|
H2SO4
|
90 | 150 | 66 | 2.9 | 0.07 | 0.6 | 0.02 |
| HCl | 5 | 100 | 38 | 0.1 | <0.01 | 0.1 | <0.01 |
| HCl | 10 | 100 | 38 | 2.1 | 0.05 | <0.1 | <0.01 |
| HCl | 15 | 100 | 38 | 2.4 | 0.06 | 7.0 | 0.18 |
| HCl | 20 | 100 | 38 | 8.0 | 0.20 | 6.3 | 0.16 |
|
HNO3
|
30 | Boiling | 3.8 | 0.10 | 3.5 | 0.09 | |
Physical Properties
| Physical Property | Customary Units | Metric Units | ||
| Density | RT |
0.307 lb/in3
|
RT |
8.50 g/cm3
|
| Electrical Resistivity | RT | 50.6 µohm.in | RT | 1.28 µohm.m |
| 200°F | 50.8 µohm.in | 100°C | 1.29 µohm.m | |
| 400°F | 51.2 µohm.in | 200°C | 1.30 µohm.m | |
| 600°F | 51.6 µohm.in | 300°C | 1.31 µohm.m | |
| 800°F | 52.2 µohm.in | 400°C | 1.32 µohm.m | |
| 1000°F | 52.9 µohm.in | 500°C | 1.34 µohm.m | |
| 1200°F | 53.0 µohm.in | 600°C | 1.35 µohm.m | |
| Thermal Conductivity | RT |
63 Btu.in/h.ft2.°F
|
RT | 9.1 W/m.°C |
| 200°F |
74 Btu.in/h.ft2.°F
|
100°C | 10.8 W/m.°C | |
| 400°F |
88 Btu.in/h.ft2.°F
|
200°C | 12.6 W/m.°C | |
| 600°F |
99 Btu.in/h.ft2.°F
|
300°C | 14.1 W/m.°C | |
| 800°F |
114 Btu.in/h.ft2.°F
|
400°C | 16.1 W/m.°C | |
| 1000°F |
133 Btu.in/h.ft2.°F
|
500°C | 18.0 W/m.°C | |
| 1200°F |
162 Btu.in/h.ft2.°F
|
600°C | 21.6 W/m.°C | |
| Mean Coefficient of Thermal Expansion | 77-200°F | 6.9 µin/in.°F | 25-100°C | 12.4 µm/m.°C |
| 77-400°F | 6.9 µin/in.°F | 25-200°C | 12.4 µm/m.°C | |
| 77-600°F | 7.0 µin/in.°F | 25-300°C | 12.6 µm/m.°C | |
| 77-800°F | 7.2 µin/in.°F | 25-400°C | 12.9 µm/m.°C | |
| 77-1000°F | 7.4 µin/in.°F | 25-500°C | 13.2 µm/m.°C | |
| 77-1200°F | 7.6 µin/in.°F | 25-600°C | 13.3 µm/m.°C | |
| Thermal Diffusivity | RT |
0.10 ft2/h
|
RT | 0.025 cm2/s |
| 200°F |
0.11 ft2/h
|
100°C |
0.029 cm2/s
|
|
| 400°F |
0.13 ft2/h
|
200°C |
0.033 cm2/s
|
|
| 600°F |
0.14 ft2/h
|
300°C |
0.036 cm2/s
|
|
| 800°F |
0.16 ft2/h
|
400°C |
0.040 cm2/s
|
|
| 1000°F |
0.17 ft2/h
|
500°C |
0.043 cm2/s
|
|
| 1200°F |
0.19 ft2/h
|
600°C |
0.047 cm2/s
|
|
| Specific Heat | RT | 0.102 Btu/lb.°F | RT | 428 J/kg.°C |
| 200°F | 0.104 Btu/lb.°F | 100°C | 434 J/kg.°C | |
| 400°F | 0.106 Btu/lb.°F | 200°C | 443 J/kg.°C | |
| 600°F | 0.109 Btu/lb.°F | 300°C | 455 J/kg.°C | |
| 800°F | 0.113 Btu/lb.°F | 400°C | 468 J/kg.°C | |
| 1000°F | 0.121 Btu/lb.°F | 500°C | 486 J/kg.°C | |
| Dynamic Modulus of Elasticity | RT |
30.0 x 106psi
|
RT | 207 GPa |
| 600°F |
27.5 x 106psi
|
300°C | 191 GPa | |
| 800°F |
25.6 x 106psi
|
400°C | 180 GPa | |
| 1000°F | 24.8 x 106psi | 500°C | 173 GPa | |
| 1200°F |
23.5 x 106psi
|
600°C | 166 GPa | |
| Melting Range | 2422-2476°F | – | 1328-1358°C | – |
RT= Room Temperature
Impact Strength
| Product Form | Test Temperature | Impact Strength | ||
| °F | °C | ft-lbf | J | |
| Plate | RT | RT | 362 | 491 |
| Plate | -320 | -196 | 419 | 568 |
| Bar | RT | RT | 369 | 500 |
| Bar | -320 | -196 | 423 | 574 |
Impact strengths were generated using Charpy V-notch samples, machined from mill annealed material.