| Table 1 Nominal composition of nickel-containing alloys many are used in Caustic Soda | |||||||||
| composition, % | ASTM Spec.b | ||||||||
| Alloy | UNS
Number a |
Ni |
C |
Cr |
Mo |
Cu |
Fe |
Plate | Pipe |
| Group I – Commercially pure (C.P.) nickel and nickel-copper alloys | |||||||||
| 200 | N02200 | 99.5 | 0.08 | – | – | – | 0.2 | B162 | B161 |
| 201 | N02201 | 99.5 | 0.01 | – | – | – | 0.2 | B162 | B161 |
| 400 | N04400 | 66.5 | 0.2 | – | – | Bal | 1.2 | B127 | B165 |
| K500 | N05500 | 66.5 | 0.25 | – | – | Bal | 1.2 | B127 | B165 |
| Group II – Chromium-containing nickel alloys | |||||||||
| 600 | N06600 | 76 | 0.08 | 15.5 | – | – | 8 | B168 | B167 |
| 601 | N06601 | 60 | 0.05 | 23 | – | – | Bal | B168 | B167 |
| 825 | N08825 | 42 | 0.03 | 21.5 | 3 | 2.25 | 30 | B424 | B163 |
| 625 | N06625 | 61 | 0.05 | 21.5 | 9 | – | 2.5 | B443 | B444 |
| C-22/622 | N06022 | 56 | 0.01 | 21.5 | 13.5 | – | 4 | B575 | B622 |
| C-276 | N10276 | 58 | 0.01 | 15.5 | 16 | – | 5.5 | B575 | B622 |
| 33 | R20033 | 32 | 0.08 | 33 | 1.6 | 3 | 32 | B625 | B622 |
| 59 | N06059 | 60 | 0.01 | 23 | 15.5 | – | 0.7 | B575 | B622 |
| Group III – Nickel-molybdenum alloys | |||||||||
| B-2 | N10665 | 69 | 0.01 | 1 | 28 | – | 2 | B333 | B622 |
| Ni-Resist (castings) | |||||||||
| Type 1 | F41000 | 15 | 2 | 2 | – | – | Bal | – | – |
| Type 2 | F41002 | 20 | 2 | 2 | – | – | Bal | – | – |
| Type D2 | F43000 | 20 | 2 | 2 | – | – | Bal | – | – |
| Ferritic stainless steels | |||||||||
| 430 | S43000 | – | 0.05 | 17 | – | – | Bal | A240 | A268 |
| 444 | S44400 | – | 0.02 | 18 | 2 | – | Bal | A240 | A268 |
| XM-33 | S44626 | – | 0.03 | 26 | 1 | – | Bal | A240 | A268 |
| XM-27 | S44627 | – | 0.005 | 26 | 1 | – | Bal | A240 | A268 |
| 29-4 | S44700 | – | 0.005 | 29 | 4.0 | – | Bal | A240 | A268 |
| Austenitic stainless steels | |||||||||
| 304 | S30400 | 8 | 0.04 | 18 | – | – | Bal | A240 | A312 |
| 304L | S30403 | 8 | 0.02 | 18 | – | – | Bal | A240 | A312 |
| 316 | S31600 | 10 | 0.04 | 16.5 | 2.1 | – | Bal | A240 | A312 |
| 316L | S31603 | 10 | 0.02 | 16.5 | 2.1 | – | Bal | A240 | A312 |
| 800 | N08800 | 33 | 0.07 | 21 | – | – | Bal | A240 | B407 |
| 20 | N08020 | 33 | 0.02 | 19.5 | 2.2 | 3.2 | Bal | A240 | B729 |
| 28 | N08028 | 32 | 0.03 | 27 | 3.5 | 1 | Bal | B709 | B668 |
| 6%Moc | S31254 | 18 | 0.01 | 20 | 6.2 | 0.7 | Bal | A240 | A312 |
| 6%Moc | N08367 | 24 | 0.01 | 21 | 6.2 | – | Bal | A240 | A312 |
| Table 1 Nominal composition of nickel-containing alloys many are used in Caustic Soda | |||||||||
| Composition, % | ASTM Spec.b | ||||||||
|
Alloy |
UNS
Number a |
Ni |
C |
Cr |
Mo |
Cu |
Fe |
Plate |
Seamless tube and pipe |
| Duplex stainless steel | |||||||||
| 2304 | S32304 | 4 | 0.02 | 23 | 0.3 | – | Bal | A240 | A790 |
| 2205 | S32205 | 5 | 0.02 | 22 | 3.2 | – | Bal | A240 | A790 |
| 2507 | S32750 | 7 | 0.02 | 25 | 4 | – | Bal | A240 | A790 |
| 7-Mo Plus | S32950 | 4 | 0.03 | 27.5 | 2 | – | Bal | A240 | A790 |
| S32906 | 7 | 0.02 | 29 | 2.3 | – | Bal | A240 | A790 | |
| Copper-nickel alloys | |||||||||
| 90-10 | C70600 | 10 | – | – | – | Bal | 1.2 | B171 | B466 |
| 70-30 | C71500 | 31 | – | – | – | Bal | 0.8 | B171 | B466 |
a – UNS numbers beginning with an “N” indicate a nickel alloy, but the definition of a nickel alloy is different than that used by ASTM.
b – in ASTM specifications, most nickel alloys fall into the “B” specifications. However, due to a redefinition of a nickel alloy, a few alloys such as Alloy 20 are being reclassified as stainless steels, and will be included in the “A” specifications. That work is still in progress.
c – the 6% Mo alloys are a series of stainless steels, many of which are proprietary, all with roughly 6%Mo content and roughly equivalent in performance.





