Hangbo Alloy Group
Shanghai · Est. 2012
N08367 technical guide: nominal chemical composition, mechanical and physical properties, corrosion resistance, welding, product forms and ASTM standards...
AL-6XN (UNS N08367) is a super-austenitic stainless (6% mo). 6 % Mo super-austenitic, PREN ≈ 45. Seawater/brackish pitting & crevice resistant. This guide covers its nominal chemical composition, typical mechanical and physical properties, corrosion behaviour, welding, common applications, available product forms and the ASTM standards that apply — everything a specifier needs to evaluate AL-6XN for a project.
AL-6XN belongs to the super-austenitic stainless (6% mo) class of materials. It is 6 % mo super-austenitic, pren ≈ 45. It is seawater/brackish pitting & crevice resistant. It is cost-effective vs solid nickel alloys.
Nominal (wt%) composition of AL-6XN (UNS N08367):
| Element | Composition (wt%) |
|---|---|
| Nickel (Ni) | 23.5 – 25.5 |
| Chromium (Cr) | 20.0 – 22.0 |
| Molybdenum (Mo) | 6.0 – 7.0 |
| Nitrogen (N) | 0.18 – 0.25 |
| Iron (Fe) | Balance |
| Carbon (C) | ≤ 0.030 |
| Manganese (Mn) | ≤ 2.0 |
| Silicon (Si) | ≤ 1.0 |
| Copper (Cu) | ≤ 0.75 |
| Phosphorus (P) | ≤ 0.040 |
| Sulphur (S) | ≤ 0.030 |
Typical physical properties:
| Property | Value |
|---|---|
| Density | 8.06 g/cm³ |
| Melting Range | 1320 – 1400 °C |
| Thermal Expansion (20–1000 °C) | 15.5 µm/m·K |
| Thermal Conductivity (100 °C) | 13.0 W/m·K |
| Electrical Resistivity | 0.95 µΩ·m |
| Modulus of Elasticity | 200 GPa |
Typical room-temperature mechanical properties (annealed / specified condition unless noted):
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm) | 655 MPa (95 ksi) |
| Yield Strength, 0.2% (Rp0.2) | 310 MPa (45 ksi) |
| Elongation in 50 mm | 40% |
| Hardness (Rockwell B) | 80 – 95 HRB |
| Property | Value |
|---|---|
| Service temperature | Cryogenic to ≈ 300 °C |
| Service note | PREN ≈ 45 |
Its pitting resistance equivalent number (PREN) is approximately ≈ 45, placing it among the more locally-corrosion-resistant grades for chloride service. AL-6XN is a 6 % molybdenum super-austenitic stainless with PREN ≈ 45, providing excellent resistance to pitting and crevice corrosion in seawater, brackish water and chloride process streams. It bridges the gap between duplex stainless and the solid nickel alloys at much lower cost, and stays tough at cryogenic temperatures.
Welded with matching 6Mo fillers (e.g., ERNiCrMo-3) to preserve corrosion resistance; the nitrogen-stabilised structure resists sensitisation. Follow a qualified procedure.
The grade is supplied to the following common specifications:
| Standard | Product Form / Scope |
|---|---|
| ASTM A240 | Plate, sheet & strip |
| ASTM A312/A358 | Pipe |
| ASTM A376 | Seamless pipe |
| ASTM A182 | Flanges & forgings |
Standards & References. Specifications cited on this page; confirm current revisions with the issuing body.
General references: Nickel Institute · AMPP (corrosion) · SAE International · ASTM International
AL-6XN (UNS N08367) is a 6 % molybdenum super-austenitic stainless with PREN ≈ 45, giving excellent resistance to pitting and crevice corrosion in seawater and chloride process streams at much lower cost than solid nickel alloys.
Annealed: ≈ 655 MPa tensile, ≈ 310 MPa yield, 40 % elongation, 80–95 HRB.
AL-6XN has far higher molybdenum and nitrogen (PREN ≈ 45 vs ≈ 25), so it resists chloride pitting and crevice corrosion that rapidly attack 316L in seawater.
Yes, with matching 6Mo fillers (ERNiCrMo-3) to keep corrosion resistance; nitrogen stabilisation avoids sensitisation.
Seawater/brackish heat exchangers, desalination and power-plant cooling systems, bleach plants, chemical vessels and cryogenic/LNG service.
Plate/sheet/strip ASTM A240, pipe A312/A358, seamless pipe A376, flanges/forgings A182.
As a dedicated nickel alloy manufacturer serving marine, chemical processing, power generation sectors, Hangbo Alloy Group supplies the grades discussed here across all standard product forms with full ASTM/ASME documentation and EN 10204 3.1 certification. Our material is specified for applications where corrosion resistance, high-temperature strength, and traceable quality are non-negotiable. See our production & testing facilities for more on how every heat is verified.