Nickel Alloy 725
The chemical composition of INCONEL alloy 725 is given in Table 1. High levels of nickel and chromium provide corrosion resistance in reducing and oxidizing environments. The substantial molybdenum content enhances resistance to reducing media and provides a high degree of resistance to pitting and crevice corrosion. Additionally, the combination of elements makes the alloy resistant to hydrogen embrittlement and stress-corrosion cracking.
The properties of INCONEL alloy 725 are useful for a range of applications that require outstanding corrosion resistance along with high strength. The alloy is used for hangers, landing nipples, side pocket mandrels and polished bore receptacles in sour gas service, where it resists the effects of hydrogen sulfide, chlorides and carbon dioxide. The alloy is also attractive for high strength fasteners in marine applications, where it resists corrosion, pitting and crevice attack in seawater.
Alloy 725 (UNS N07725) Chemical Composition:
| Weight% | Ni | Cr | Mo | Nb | Ti | Al | C | Mn | Si | P | S | Fe |
| Alloy 725 | 55.0-59.0 | 19.0 -22.5 | 7.0-9.5 | 2.75-4.0 | 1.0-1.7 | 0.35 max | 0.03 max | 0.35 max | 0.20 max | 0.015 max | 0.010 max | Rem |
Alloy 725 (UNS N07725) Mechanical Properties:
| Material Form and Condition | Yield Strength (0.2% Offset) | Tensile Strength | Elongation % | Hardness, Rc | |||
| ksi | MPa | MPa | ksi | ||||
| Alloy 725 round | Annealed | 62.0 | 427 | 124.0 | 855 | 57 | 5 |
| Alloy 725 round | Age Hardened | 133.0 | 917 | 180.0 | 1241 | 30 | 36 |
| Transverse Specimens from hot-finished rounds of 4.0 to 7.5 in (102 to 190mm) diameter | |||||||
Available Products and Specifications
INCONEL alloy 725 is designated as UNS N07725. The product is available as a round bar and wire.
Bar and wire – ASTM B 805, ASME Code Case 2217
Bar and forging stock – SMC specification HA91, ASME Code Case 2217
