ASTM B690 Seamless UNS N08366, N08367 Alloy Pipe and Tube
- Grade: UNS N08366, UNS N08367 (AL-6XN, X1NiCrMoCuN25-20-7, EN 1.4529)
- Type: Iron-Nickel-Chromium-Molybdenum Alloys
- Pipe OD: NPS 1/4″ -6″ (13.7-168.3mm), Pipe WT: SCH 5, 10, 40, 80
- Tube OD: 6.4-152.4mm, Tube WT: 1.65-8.56mm
ASTM B690 UNS N08366 & N08367 Seamless Pipe and Tube
Golden Sunbird Metals supplies high-performance ASTM B690 seamless UNS N08366 and N08367 nickel alloy pipe and tube (also known as AL-6XN / EN 1.4529). Engineered for superior resistance to pitting, crevice corrosion, chloride-induced stress corrosion cracking, and aggressive chloride-bearing media—including seawater, brackish water, and both oxidizing and reducing corrosive conditions—these seamless pipes and tubes deliver exceptional long-term reliability in demanding chemical processing, offshore/marine, oil & gas (sour service), desalination, and wastewater treatment systems. Available in a full range of sizes (OD 6.4–152.4 mm) in annealed condition, our UNS N08366 and N08367 products fully comply with ASTM B690 standards and are supplied with comprehensive testing and EN 10204 3.1/3.2 mill certificates. Whether you need standard or custom lengths, our inventory ensures rapid turnaround and proven durability where maximum corrosion resistance in aggressive chloride environments is critical.
Chemical Composition of ASTM B690 Seamless UNS N08366, N08367 Alloy Pipe and Tube (wt.%)
| Element | Composition Limits, % (N08366) | Composition Limits, % (N08367) |
| Carbon | 0.035 max | 0.030 max |
| Manganese | 2.00 max | 2.00 max |
| Silicon | 1.00 max | 1.00 max |
| Phosphorus | 0.040 max | 0.040 max |
| Sulfur | 0.030 max | 0.030 max |
| Chromium | 20.00 to 22.00 | 20.00 to 22.00 |
| Nickel | 23.50 to 25.50 | 23.50 to 25.50 |
| Molybdenum | 6.00 to 7.00 | 6.00 to 7.00 |
| Nitrogen | … | 0.18 to 0.25 |
| Iron | remainder | remainder |
| Copper | 0.75 max | 0.75 max |
Mechanical Properties of ASTM B690 Seamless UNS N08366 (Annealed) and UNS N08367 Alloy Pipe and Tube
| Property | Specification (ksi [MPa]) |
|---|---|
| Tensile strength | 75 [517] minimum |
| Yield strength (0.2% offset) | 30 [206] minimum |
| Elongation (in 2 in. or 50 mm) | 30% minimum |
Please note, the values provided are minimum requirements; actual material properties can vary based on specific material processing and condition.
Features
- Seamless pipe and tube covered by ASTM B690 for special corrosive service and heat-resisting applications.
- Excellent resistance to pitting, crevice corrosion, and chloride-induced corrosion in aggressive environments.
- Strong performance in seawater, brackish water, and other chloride-bearing media.
- Good resistance to oxidizing and reducing corrosive conditions, making it suitable for demanding process service.
- Supplied in solution heat treated and descaled condition for reliable fabrication and corrosion performance.
Technical Specifications
| Specification | Value |
| Standard | ASTM B690 Iron-Nickel-Chromium-Molybdenum Alloy Seamless Pipe and Tube |
| Grade | UNS N08366, UNS N08367 (AL-6XN, X1NiCrMoCuN25-20-7, EN 1.4529) |
| Manufacturing Process | cold-finished of hot-finished |
| Seam Type | Seamless |
| Pipe Size | Outside Diameter (OD): NPS 1/4″ -6″, Wall Thickness (WT): SCH5, SCH10, SCH40, SCH80 |
| Tube Size | Outside Diameter (OD): 6.4 -152.4mm, Wall Thickness (WT): 1.65-8.56mm |
| Length | 6000-12000mm |
| Delivery Condition | Annealed |
| Inspection Certificate | EN 10204 Type 3.1 (Mill Test Certificate), EN 10204 Type 3.2 (Witness Testing or 3rd Party Inspection) |
| Test | Chemical analysis, Tensile test, Flattening test, Expansion test, Hydrostatic test, Nondestructive testing (NDE Test), Intergranular corrosion test, Metallographic examination |
Applications
- Heat exchangers and condensers operating with seawater or brackish water cooling.
- Chemical processing piping, reactors, transfer lines, and process equipment handling chlorides.
- Offshore platforms, subsea equipment, and marine systems exposed to seawater corrosion.
- Sour gas wells and oil & gas service equipment exposed to H2S and CO2 environments.
- Desalination systems, evaporators, and piping where pitting and crevice corrosion resistance are critical.
- Corrosive wastewater and sludge handling systems.
