ASTM B622 UNS N08031 Tube,alloy 31,W.Nr. 1.4562 alloy seamless pipe and tube
Alloy 31 Seamless & Welded Tubes | ASTM B622 Specification
ASTM B622 UNS N08031 tubes, commonly known as Alloy 31 tubes, are nickel-iron-chromium-molybdenum alloy tubes designed for extreme corrosion resistance. Manufactured in accordance with ASTM B622, UNS N08031 tubes provide outstanding performance in acidic, chloride-containing, and high-temperature environments, making them ideal for chemical processing, offshore, and pollution control applications.
What Is ASTM B622?
ASTM B622 is the standard specification for seamless and welded nickel alloy tubes for pressure and non-pressure service. The specification defines chemical composition, mechanical properties, heat treatment, dimensions, and testing requirements, ensuring reliable performance in corrosive service conditions.
Material Grade: UNS N08031 (Alloy 31)
UNS N08031, also known as Alloy 31, is a high-alloy nickel-based material with exceptional resistance to both oxidizing and reducing acids.
N08031 stainless steel is a superaustenitic (highly alloyed) stainless steel formulated for primary forming into wrought products. Cited properties are appropriate for the annealed condition. 1.4562 is the EN numeric designation for this material. N08031 is the UNS number. And Alloy 31 is the common industry name.
This material is well established: the Further Reading section below cites a number of published standards, and that list is not necessarily exhaustive.
It has a very high base cost among wrought superaustenitic stainless steels. In addition, it has a very high embodied energy and a moderately high ductility.
| 00Cr27Ni31Mo7CuN | NS1404 | alloy 31 | N08031 | 1.4562 | Nicrofer 3127hMo(VDM) |
ASTM B622 N08031 Chemical Composition
| C | Si | Mn | P | S | Cr | Cu | Mo | N | Ni | Fe | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Alloy 31 | Min % | 26,0 | 1,0 | 6,0 | 0,15 | 30,0 | balance | |||||
| Max % | 0,015 | 0,3 | 2,0 | 0,20 | 0,010 | 28,0 | 1,4 | 7,0 | 0,25 | 32,0 | balance | |
| ASTM B626 (S08031) (alloy 31) | ||||||||||||
| 1.4562 | Min % | 26,00 | 1,00 | 6,00 | 0,15 | 30,00 | ||||||
| Max % | 0,015 | 0,30 | 2,00 | 0,02 | 0,10 | 28,00 | 1,40 | 7,00 | 0,25 | 32,00 | ||
| N 08031 | Min % | 26,0 | 1,0 | 6,0 | 0,15 | 30,0 | balance | |||||
| Max % | 0,015 | 0,3 | 2,00 | 0,,20 | 0,010 | 28,0 | 1,4 | 7,0 | 0,25 | 32,0 | balance | |
Size Range & Specifications
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Outside Diameter: 6 mm – 114.3 mm (1/4″ – 4″)
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Wall Thickness: 0.5 mm – 6 mm (or as specified)
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Manufacturing Process: Seamless cold drawn / welded
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Delivery Condition: Solution annealed
Heat Treatment
ASTM B622 UNS N08031 tubes shall be supplied in solution annealed condition, followed by rapid cooling to restore corrosion resistance and ensure uniform microstructure.
ASTM B622 UNS N08031 tubes (Alloy 31) offer exceptional corrosion resistance and mechanical reliability in the most aggressive chemical environments. Fully compliant with ASTM B622, these tubes ensure long service life and reduced maintenance costs in critical applications.
