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
X2NiCrMoCu25-20-5 is a high-alloy austenitic stainless steel of the 1.4539 family, with molybdenum and copper additions. This datasheet presents the material within the European standard system.
The EN designation X2NiCrMoCu25-20-5 indicates approximately 25% nickel, 20% chromium, 4.5% molybdenum and copper, with a carbon prefix "X2" (about 0.02-0.03% C) — a slightly higher carbon variant of the ultra-low-carbon X1NiCrMoCu25-20-5 (1.4539). Like the X1 grade, the high nickel and molybdenum give good resistance to chloride stress-corrosion cracking and pitting, while the copper gives strong resistance to sulphuric and phosphoric acids.
Typical applications include equipment for sulphuric and phosphoric acid, flue-gas desulphurization, seawater systems, pulp-and-paper bleaching and general chemical-process plant requiring a 1.4539-class alloy.
Values for the solution-annealed condition, per EN reference data.
| Property | Value | Unit |
|---|---|---|
| Density | 8.0 | g/cm³ |
| Melting range | 1300-1390 | °C |
| Young's modulus (20 °C) | 195 | GPa |
| Thermal conductivity (20 °C) | 12 | W/m·K |
| Coefficient of thermal expansion (20-100 °C) | 15.3 | µm/m·°C |
| Specific heat (20 °C) | 450 | J/kg·K |
| Magnetic response | Non-magnetic (austenitic) | — |
Composition per EN 10088 (X2NiCrMoCu25-20-5).
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Iron | Fe | Balance | — | Base element |
| Nickel | Ni | 24.0 | 26.0 | Austenite stability; SCC resistance |
| Chromium | Cr | 19.0 | 21.0 | Passivity; corrosion resistance |
| Molybdenum | Mo | 4.0 | 5.0 | Pitting + crevice resistance |
| Copper | Cu | 1.2 | 2.0 | Sulphuric/phosphoric-acid resistance |
| Manganese | Mn | — | 2.0 | Deoxidiser |
| Silicon | Si | — | 0.70 | Deoxidiser |
| Nitrogen | N | — | 0.15 | Austenite stability |
| Carbon | C | — | 0.030 | Low (the "X2" variant; slightly above X1) |
| Phosphorus | P | — | 0.030 | Residual impurity |
| Sulphur | S | — | 0.010 | Residual impurity |
Nominal: 25Ni-20Cr-4.5Mo-1.5Cu. The "X2" prefix denotes a low carbon (~0.02-0.03%), slightly above the ultra-low-carbon X1NiCrMoCu25-20-5 (1.4539).
Solution-annealed (+AT) condition, per EN 10088.
| Property | Value | Unit |
|---|---|---|
| Tensile strength (Rm) | 520-720 | MPa |
| 0.2% proof strength (Rp0.2) | >=220 | MPa |
| Elongation at fracture (A) | >=35 | % |
| Brinell hardness | <=220 | HB |
| Impact energy (KV, +20 °C) | >=100 | J |
Values per EN 10088. Confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| Sulphuric acid | Excellent | Cu addition is key |
| Phosphoric acid | Excellent | Including wet-process acid |
| Chloride pitting | Good | PREN ~34-36 |
| Crevice corrosion | Good | Better than 1.4404 |
| Chloride SCC | Excellent | High Ni content |
| Intergranular | Good | Low carbon |
A solid-solution alloy; it cannot be hardened by heat treatment.
Solution Anneal approximately 1060-1140 °C, followed by rapid cooling (water or air) to dissolve secondary phases and retain optimum corrosion resistance.
Weldable by gas-shielded arc welding with a matching or over-alloyed nickel-base filler.
| Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Excellent | Matching or Ni-base (NiCr21Mo type) |
| GMAW / MIG | Good | Matching or Ni-base |
| SMAW / stick | Good | Matching or Ni-base electrode |
No preheat required; control interpass temperature.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Machinability | Moderate; work-hardens; sharp tooling, slow-to-moderate speeds, positive feeds |
| Work hardening | Higher than carbon steel; avoid dwelling |
| Coolant | Ample flood coolant |
Forming Processes
| Process | Notes |
|---|---|
| Cold forming | Good ductility; work-hardens |
| Hot forming | ~1150-900 °C; solution anneal + quench afterward |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Chemical processing | Sulphuric/phosphoric-acid equipment | Cu-enhanced acid resistance |
| Flue-gas desulphurization | Scrubbers, ducting | Chloride + acid resistance |
| Marine / seawater | Heat exchangers, condensers | Pitting + SCC resistance |
| Pulp & paper | Bleaching equipment | Halide resistance |
| Product Form | Standard | Notes |
|---|---|---|
| Plate, sheet and strip | EN 10088-2 · X2NiCrMoCu25-20-5 | — |
| Bar, rod, wire and sections | EN 10088-3 · X2NiCrMoCu25-20-5 | — |
| Seamless / welded tube | EN 10216-5 / EN 10217-7 | — |
| Sour service | ISO 15156-3 | Acid-gas applications |
High-alloy austenitic stainless steel (1.4539 family, X2 variant). EN 10088.
| W.Nr. / Grade | Cr % | Mo % | Cu % | C % | Best Used For |
|---|---|---|---|---|---|
| X2NiCrMoCu25-20-5 | 19-21 | 4.0-5.0 | 1.2-2.0 | <=0.03 | X1NiCrMoCu25-20-5 family (X2 variant) |
| X1NiCrMoCu25-20-5 (X1) | 19-21 | 4.0-5.0 | 1.2-2.0 | <=0.02 | Ultra-low-carbon X1NiCrMoCu25-20-5 |
| X2CrNiMo17-12-2 | 16.5-18.5 | 2.0-2.5 | — | <=0.03 | General corrosion service |
| X1CrNiMoCuN20-18-7 (X1CrNiMoCuN20-18-7-type) | 19.5-20.5 | 6.0-7.0 | 0.5-1.0 | <=0.02 | 6Mo seawater service |
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