Sep 4 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Manufacturing Process
Machinability
Forming
Welding
Forging
Hot Working
Cold Working
Annealing
Applications
Introduction
Alloy 925 is a precipitation-hardenable nickel-iron-chromium alloy with added copper and molybdenum. It exhibits high strength and excellent resistance to pitting, crevice corrosion, and stress-corrosion cracking in many aqueous environments containing chlorides and sulfides.
The following datasheet will provide more details about alloy 925.
Chemical Composition
The following table shows the chemical composition of alloy 925.
|
Element |
Content (%) |
|
Nickel, Ni |
44 |
|
Iron, Fe |
28 |
|
Chromium, Cr |
21 |
|
Molybdenum, Mo |
3 |
|
Titanium, Ti |
2.1 |
|
Copper, Cu |
1.8 |
|
Aluminum, Al |
0.3 |
|
Carbon, C |
0.01 |
Physical Properties
The physical properties of alloy 925 are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
8.05 g/cm³ |
0.291 lb/in³ |
|
Melting point |
1311-1366°C |
2392-2491°F |
Mechanical Properties
The mechanical properties of alloy 925 are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength (Precipitation-hardened. Value at room temperature) |
1210 MPa |
175000 psi |
|
Yield strength (Precipitation-hardened. Value at room temperature) |
810 MPa |
117000 psi |
|
Elongation at break (Precipitation-hardened) |
24% |
24% |
Thermal Properties
The thermal properties of alloy 925 are given in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion coefficient (@20-100°C/68-212°F) |
13.2 µm/m°C |
7.33 µin/in°F |
Manufacturing Process
Machinability
Alloy 925 can be machined using conventional machining techniques used for iron-based alloys.
Forming
The alloy has good ductility, and it can be readily formed by all conventional forming methods.
Welding
Welding of alloy 925 can be performed using gas-tungsten arc welding, shielded metal arc-welding and submerged arc welding.
Forging
Forging is performed at temperatures ranging from 927 to 1177°C (1700 to 2150°F).
Hot Working
The alloy is hot-worked in the temperatures ranging from 871 to 982°C (1600 to 1800°F).
Cold Working
Cold working of the alloy can be done using standard tooling. Plain carbon tool steels are not recommended for forming this alloy as they tend to produce galling.
Annealing
Alloy 925 is annealed at 1010°C (1850°F) for at least 2 h and then air cooled.
Applications
The following are some of the major applications of alloy 925:
-
Gas well components
-
Valves and tubing
-
High-strength piping systems