Incoloy alloy 925 is an age hardenable nickel-iron-chromium alloy with additions of molybdenum, copper, titanium and aluminum. The nickel content is sufficient for protection against chloride-ion stress corrosion cracking. The nickel, in conjunction with the molybdenum and copper, also gives outstanding resistance to reducing chemicals. The molybdenum aids resistance to pitting and crevice corrosion. The alloy’s chromium content provides resistance to oxidizing environments. The titanium and aluminum additions cause a strengthening reaction during heat treatment.
Available Forms of Incoloy 925 at Rooplaxmi Steels:
• Bar
• Sheet
• Plate
• Pipe & Tube (welded and seamless)
• Pipe Fittings
• Wire
Characteristics of Incoloy 925:
• Good mechanical properties - tensile, fatigue and creep-rupture
• Yield tensile strength, creep, and rupture strength properties are exceedingly high
• Highly resistant to chloride and sulphide stress corrosion cracking
• Resistant to aqueous corrosion and chloride ion stress corrosion cracking
• High temperature resistant
• Age-hardenable with a unique property of slow aging response that permits heating and cooling during annealing without the danger of cracking
• Excellent welding characteristics, resistant to post weldage cracking
Incoloy 925 Chemical Composition, %:
Ni |
Cr |
Fe |
Mo |
Cu |
Ti |
Al |
Mn |
42.0-46.0 |
19.5-22.5 |
22 min |
2.5-3.5 |
1.5-3.0 |
1.9-2.4 |
0.1-0.5 |
1.0 max |
Si |
Nb |
C |
S |
0.5 max |
0.5 max |
0.03 max |
0.03 max |
Application of Incoloy 925:
• High Strength Piping Systems
• Petroleum Industry
• Shafting products and fasteners
• Gas well components
Machining and Fabrication with Incoloy 925:
Incoloy 925 can be machined using conventional machining methods which are used for iron based alloys. Heavy-duty lubricants are used while cold forming. Shielded metal-arc welding, gas metal-arc welding, gas-tungsten arc welding, and submerged-arc welding methods are preferred for welding Incoloy 925. It is heat treated by annealing at 983 to 1038°C (1800 to 1900°F) followed by cooling. Forging of Incoloy 925 is done at 927 to 1177°C (1700 to 2150°F). Incoloy 925 is hot worked at 872 to 983°C (1600 to 1800°F). It can be cold worked using standard tooling. It is annealed at 1010°C (1850°F) for 2 h followed by air cooling. Incoloy 925 is hardened by heat treatment and cold working.
Incoloy 925 should be welded using gas-tungsten-arc welding, with filler materials of base-metal composition
Mechanical Properties of Incoloy 925:
At Room Temperature
Ultimate Tensile Strength |
175000 psi |
Yield |
(0.2 % offset) 117000 psi |
Elongation |
24 % |