| Ni-Resist irons contain an austenitic matrix with about 10% alloy carbides. The austenitic structure is suitable for corrosive environments in sour well oils, salts, salt water acids and alkalies. The iron is relatively soft and chrome is added to produce carbides that help improve wear resistance. Ni-Resist is more dense than gray or ductile irons and will have a higher coefficient of thermal expansion. Dura-Bar 201 Ni-Resist is manufactured to produce a material conforming to ASTM A436, Type 1. The microstructure will consist of Type VII, type A, size 4-6, graphite as defined in ASTM A247. The matrix will be austenite with 5-10% alloy carbide. The rim will
contain type D graphite, size 6-8. Chill carbides will be less than 5% in any field at 100x and will be well dispersed. Austenitic alloys cannot be hardened by heat treatment. They may be softened and homogenized by heating to 1800-1900F (980-1040C) for 3-5 hours and air cooling. This breaks down some of the carbides and most of those remaining will be spheroidized. Annealing softens the material without detrimental effect on the strength properties. Dura-Bar 201 Ni-Resist should not be used in applications involving service above 1300F (705C). Composition: Typical chemical composition and ranges, actual values depend on cross section size. Information provided by Dura-Bar. |
| Cast iron, gray iron, ASTM A436 Type 1 |
