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
1.4477 is a high-chromium, low-molybdenum super duplex stainless steel , with a microstructure of roughly equal ferrite and austenite. This datasheet presents the material within the European standard system.
The EN designation 1.4477 indicates approximately 29% chromium, 7% nickel and 2% molybdenum, with a high nitrogen addition. Compared with the 2507-type super duplex 1.4410 (25Cr-7Ni-4Mo), 1.4477 substitutes higher chromium and nitrogen for part of the molybdenum, giving a high PREN with good resistance to chloride pitting and stress-corrosion cracking, while improving resistance in certain acidic/abrasive media. It must not be confused with the 4%-molybdenum grade 1.4410; the chemistries are different (29Cr-2Mo versus 25Cr-4Mo).
Typical applications include seawater and brackish-water systems, umbilical and hydraulic tubing, oil-and-gas equipment, and process equipment requiring high strength with high-chloride corrosion resistance.
| Property | Value | Unit |
|---|---|---|
| Density | 7.8 | g/cm³ |
| Melting range | 1350-1400 | °C |
| Young's modulus (20 °C) | 200 | GPa |
| Thermal conductivity (20 °C) | 15 | W/m·K |
| Coefficient of thermal expansion (20-100 °C) | 13 | µm/m·°C |
| Specific heat (20 °C) | 480 | J/kg·K |
| Magnetic response | Ferromagnetic (duplex) | — |
| Element | Symbol | Min % | Max % | Role in Alloy |
|---|---|---|---|---|
| Iron | Fe | Balance | — | Base element |
| Chromium | Cr | 28.0 | 30.0 | Ferrite former; corrosion resistance |
| Nickel | Ni | 5.8 | 7.5 | Austenite former; phase balance |
| Molybdenum | Mo | 1.5 | 2.6 | Pitting + crevice resistance |
| Nitrogen | N | 0.30 | 0.40 | Austenite former; strength; pitting |
| Manganese | Mn | 0.80 | 1.50 | Deoxidiser; N solubility |
| Silicon | Si | — | 0.50 | Deoxidiser |
| Carbon | C | — | 0.030 | Low (intergranular resistance) |
| Phosphorus | P | — | 0.030 | Residual impurity |
| Sulphur | S | — | 0.015 | Residual impurity |
Solution-annealed (+AT) condition, per EN 10088-3 for W.Nr. 1.4477.
| Property | Value | Unit |
|---|---|---|
| Tensile strength (Rm) | 750-1000 | MPa |
| 0.2% proof strength (Rp0.2) | >=550 | MPa |
| Elongation at fracture | >=25 | % |
| Impact energy (KV, +20 °C) | >=100 | J |
| Brinell hardness | <=290 | HB |
Values per EN 10088-3. Confirm against the inspection certificate (EN 10204).
| Environment | Performance | Notes |
|---|---|---|
| Chloride pitting | Outstanding | High Cr + N |
| Crevice corrosion | Outstanding | High-Cr duplex |
| Chloride SCC | Excellent | Duplex structure |
| Seawater | Excellent | Warm chlorinated seawater |
| General (oxidizing) | Excellent | Very high chromium |
| Intergranular (welded) | Resistant | Low carbon |
The high-chromium chemistry gives excellent localized-corrosion resistance, comparable to the 2507 family with a different alloying balance.
Not hardenable by heat treatment; properties are set by solution annealing and phase balance.
Solution Anneal approximately 1040-1120 °C, followed by rapid water quench to retain the balanced ferrite-austenite structure. Rapid cooling is critical owing to the high alloy content. Avoid prolonged exposure in the 300-1000 °C range (sigma-phase / 475 °C embrittlement).
Weldable by common fusion methods with a matching or over-alloyed super-duplex filler and controlled heat input to maintain phase balance.
| Process | Applicability | Filler / Consumable |
|---|---|---|
| GTAW / TIG | Good | Over-alloyed super-duplex filler |
| GMAW / MIG | Good | Super-duplex filler |
| SMAW / stick | Good | Matching super-duplex electrode |
No preheat; control interpass temperature and heat input; resistant to intergranular corrosion in the as-welded condition owing to the low carbon.
Machining Guidelines
| Parameter | Recommendation |
|---|---|
| Machinability | Difficult; high strength + work-hardening; rigid setup, carbide tools, low speeds |
| Work hardening | High rate; positive feeds, avoid dwelling |
| Coolant | Ample flood coolant |
Forming Processes
| Process | Notes |
|---|---|
| Hot forming | ~1230-1000 °C; solution anneal + quench afterward |
| Cold forming | Higher forces than 1.4462 (very high strength) |
| Industry | Typical Components | Key Requirements |
|---|---|---|
| Marine / seawater | Seawater systems, umbilical tubing | Warm chloride resistance |
| Oil & gas | Hydraulic / umbilical tubing, components | Pitting + sour-service resistance |
| Desalination | Heat exchangers, piping | Hot chloride resistance |
| Chemical processing | Vessels, piping | Localized-corrosion resistance |
| Product Form | Standard | Notes |
|---|---|---|
| Plate, sheet and strip | EN 10088-2 · W.Nr. 1.4477 | X2CrNiMoN29-7-2 |
| Bar, rod, wire and sections | EN 10088-3 / EN 10088-5 · W.Nr. 1.4477 | — |
| Seamless tube | EN 10216-5 / EN 10297-2 · W.Nr. 1.4477 | — |
| Sour service | ISO 15156-3 | Acid-gas applications |
High-chromium super duplex stainless steel. W.Nr. 1.4477; EN 10088-3.
| W.Nr. | Cr % | Ni % | Mo % | N % | Best Used For |
|---|---|---|---|---|---|
| 1.4477 | 28-30 | 5.8-7.5 | 1.5-2.6 | 0.30-0.40 | High-Cr super duplex (low Mo) |
| 1.4410 | 24-26 | 6.0-8.0 | 3.0-4.5 | 0.24-0.35 | 2507 super duplex (high Mo) |
| 1.4501 | 24-26 | 6.0-8.0 | 3.0-4.0 | 0.20-0.30 | Super duplex with W + Cu |
| 1.4462 | 21-23 | 4.5-6.5 | 2.5-3.5 | 0.10-0.22 | Standard duplex |
| 1.4404 | 16.5-18.5 | 10-13 | 2.0-2.5 | — | Austenitic general service |
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