Bar and Rod
Plate and Sheet
Strip
Pipe and Tube
Wire
Welding
Powder Material
Cast Products
Forged Products
Fittings
Fastening
Round Bar:
φ2–500 mm, 1–6 m length
Flat/Square Bar:
4–100 mm thickness/width
Hex Bar:
A/F 3–100 mm
Hollow Bar:
OD 20–300 mm
Sheet:
0.3–6 mm thickness
Medium Plate:
6–25 mm thickness
Heavy Plate:
25–100 mm thickness
Standard Strip:
0.05–3 mm thick,
10–600 mm wide
Precision strip:
0.01–0.5 mm thick,
tight tolerance ±0.005 mm
Foil:
0.005–0.1 mm thick
Seamless Tube:
OD 6–450 mm,
WT 1–50 mm,
1–12 m length
Welded Tube:
OD 10–600 mm,
WT 1–20 mm
Capillary Tube:
OD 1–10 mm,
WT 0.1–2 mm
Wire Form:
Cold Drawn Wire,
Bright Wire,
Spring Wire,
Fine Wire,
Ultra-fine Wire
General Diameter:
φ0.1–10 mm
Coil Weight:
50–500 kg,
customizable tolerance
Solid Wire:
φ0.8–4.0 mm
Flux-cored Wire:
φ1.2–4.0 mm
Welding Rod:
φ2.0–5.0 mm
Powder Form:
AM 3D Printing Powder,
Spherical Powder,
Gas-atomized Powder,
Water-atomized Powder
Particle Size:
10–150 μm
Sphericity:
≥90% for AM grade
Cast Ingot:
φ200–800 mm
Precision Casting:
min wall 0.5 mm
Cast Pipe:
OD 100–600 mm,
WT 10–50 mm
Forged Bar:
Φ35–500 mm
Forged Ring:
OD 200–2000 mm
Forging Weight:
1–5000 kg
Fittings Form:
Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint
Size range:
1/2''–24'' (DN15–DN600)
Wall thickness:
Sch10–Sch160, STD, XS, XXS
Pressure Class:
150–2500 LB
Fastening Form:
Bolt, Nut, Screw, Stud, Washer, Pin, Rivet
Metric: M3–M64
Imperial: #4–2.5''
Length: 6–500 mm
Alloy 925 is an age-hardenable nickel-iron-chromium alloy with additions of molybdenum, copper, titanium and aluminium. This datasheet presents the material within the American (ASTM / ASME / UNS) standard system.
Essentially an age-hardenable version of the corrosion-resistant alloy 825, Alloy 925 combines the high strength of a precipitation-hardenable alloy with excellent corrosion resistance. The nickel content is sufficient to protect against chloride-ion stress-corrosion cracking; the nickel together with molybdenum and copper gives outstanding resistance to reducing chemicals; the molybdenum aids resistance to pitting and crevice corrosion; and the chromium provides resistance in oxidizing environments. The titanium and aluminium additions allow strengthening through precipitation of γ′ (Ni₃(Al,Ti)) during ageing. Because of its resistance to sulfide stress cracking and stress-corrosion cracking in sour (H₂S-containing) crude oil and natural gas, it is widely used for oilfield hardware; it is qualified under NACE MR0175 and API 6ACRA and supplied in the solution-annealed and aged condition.
Typical applications include down-hole and surface gas-well components — tubulars, valves, hangers, landing nipples, tool joints and packers — fasteners, and marine and pump shafting.
| Property | Value | Unit |
|---|---|---|
| Density | 8.14 | g/cm³ |
| Melting range | 1300–1370 | °C |
| Elastic modulus | 199 | GPa |
| Coefficient of thermal expansion (20–100 °C) | 13.1 | µm/m·°C |
| Thermal conductivity (20 °C) | 11.0 | W/m·K |
| Specific heat (20 °C) | 435 | J/kg·K |
| Structure | Austenitic (FCC) | — |
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Nickel | Ni | 42.0 | 46.0 | Austenite former; chloride-SCC resistance; γ′ matrix |
| Iron | Fe | Balance | — | Base element (~22%) |
| Chromium | Cr | 19.5 | 22.5 | Oxidation / pitting resistance |
| Molybdenum | Mo | 2.50 | 3.50 | Pitting / crevice / reducing-acid resistance |
| Copper | Cu | 1.50 | 3.00 | Resistance to reducing chemicals |
| Titanium | Ti | 1.90 | 2.40 | γ′ (Ni₃Ti) precipitation strengthening |
| Aluminium | Al | 0.10 | 0.50 | γ′ formation |
| Manganese | Mn | — | 1.00 | Deoxidiser |
| Carbon | C | — | 0.03 | Residual |
Solution-annealed and aged condition, typical values for UNS N09925.
| Condition | Property | Value |
|---|---|---|
| Solution annealed & aged | Tensile strength (UTS) | ≥1100 MPa (160 ksi) |
| Solution annealed & aged | 0.2% yield strength | ≥760 MPa (110 ksi) |
| Solution annealed & aged | Elongation at break | ≥18 % |
| Solution annealed & aged | Reduction of area | ≥35 % |
| Solution annealed & aged | Hardness | ≤38 HRC |
Confirm against the mill test report. The hardness limit and microstructure are controlled for sour-service qualification under NACE MR0175.
| Environment | Performance | Notes |
|---|---|---|
| Sour gas (H₂S / CO₂) | Excellent | Qualified to NACE MR0175 / API 6ACRA |
| Chloride stress-corrosion cracking | Excellent | High nickel content |
| Pitting / crevice corrosion | Excellent | Molybdenum-bearing |
| Reducing acids (sulfuric, phosphoric) | Excellent | Ni + Mo + Cu |
| Seawater | Excellent | Resists pitting and crevice attack |
The alloy resists general corrosion, pitting, crevice corrosion, intergranular corrosion and stress-corrosion cracking in both reducing and oxidizing environments, and is particularly suited to sour crude oil and natural gas, sulfuric and phosphoric acids, and seawater.
An age-hardenable corrosion-resistant alloy; strengthened by solution annealing followed by ageing.
Solution Treatment Solution anneal at approximately 980–1010 °C and cool, retaining a clean solid solution for machining and forming.
Precipitation Hardening (Ageing) Age at approximately 730–750 °C (1350–1380 °F) for 6–9 hours, furnace cool to about 620 °C (1150 °F) and hold for a total ageing time of about 18 hours, then cool at a rate equivalent to air cooling or faster — precipitating γ′ (Ni₃(Al,Ti)). The schedule meets the requirements of NACE MR0175.
Good weldability; welding is performed in the solution-annealed condition with post-weld ageing. Matching or compatible nickel-alloy fillers are used.
| Welding Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Good | Matching or compatible nickel-alloy filler |
| GMAW / MIG | Good | Compatible filler |
| EBW / laser | Good | Autogenous or matching filler |
Weld in the solution-annealed condition; apply post-weld solution and ageing to develop properties.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Preferred condition | Solution-annealed for machining, then age |
| Machinability | Difficult; rigid setups, carbide tooling, slow speeds |
| Coolant | Ample coolant |
Forming Processes
| Process | Notes |
|---|---|
| Cold forming | In the annealed condition; work-hardens |
| Hot forming | Readily forged; solution and age afterward |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Oil & gas (downhole) | Tubulars, hangers, landing nipples, packers | Strength + sour-service corrosion resistance |
| Oil & gas (surface) | Valves, tool joints, wellhead components | Strength + H₂S / CO₂ resistance |
| Marine | Pump and propeller shafting, fasteners | Strength + seawater resistance |
| Chemical process | High-strength piping systems | Reducing-acid + chloride resistance |
| Product Form | ASTM Standard | ASME / Other |
|---|---|---|
| Tube and pipe | ASTM B805 | ASME Code Case 2218 |
| Bar, rod and forging stock | ASTM B637 / B649 | API 6ACRA |
| Sour-service qualification | NACE MR0175 / ISO 15156 | — |
| Material designation | UNS N09925 | Age-hardened 825 derivative |
Age-hardenable nickel-iron-chromium alloy with Mo, Cu, Ti and Al. UNS N09925.
| Alloy | Ni % | Strengthening | Strength | Best Used For |
|---|---|---|---|---|
| Alloy 925 | 42–46 | γ′ (Al, Ti) | ~110 ksi YS | Age-hardened 825; high strength + sour-service corrosion resistance |
| Alloy 825 | 38–46 | Solid solution | Annealed | Corrosion-resistant base alloy (925 base) |
| Alloy 725 | 55–59 | γ′ + γ″ (Nb, Ti) | ~120 ksi YS | Higher-strength age-hardened 625; sour service |
| Alloy 718 | 50–55 | γ′ + γ″ (Nb, Ti) | ~150 ksi YS | Most-used high-strength superalloy |
| Alloy K-500 | 63–70 | γ′ (Al, Ti) | ~100 ksi YS | Age-hardened Ni-Cu; marine, sour service |
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