ASTM B622 / ASME SB-622 / UNS N08031 / W.Nr. 1.4562
UNS N08031 (W.Nr. 1.4562) seamless tube, offered as Alloy 31 seamless tubes, is made by Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. at its Ban Bueng, Chonburi plant to ASTM B622 / ASME SB-622. A low-carbon nickel-iron-chromium-molybdenum-copper alloy with nitrogen, it is one of the iron-bearing alloys in our nickel alloy seamless tubes range, used in heat exchangers, evaporators and condensers on phosphoric acid, sulfuric acid, flue gas desulfurization and brine duty. Our Bang Phli, Samut Prakan office handles quotations and documents.
Alloy 31 seamless tubeUNS N08031 / W.Nr. 1.4562
EN 10204 3.1 certificate / 3.2 on request
Each tube line is defined by outside diameter, minimum or average wall and length, the basis ASTM B622 sets for tube. The table gives the range we quote, the delivery condition and the tests applied before dispatch.
ASTM B622, the Standard Specification for Seamless Nickel and Nickel-Cobalt Alloy Pipe and Tube, lists UNS N08031 among the alloys that can be certified to it. For Boiler and Pressure Vessel Code work the related specification is SB-622, so an ASME SB-622 UNS N08031 seamless tube carries the same UNS number on its marking and certificate. B622 defines tube as a hollow product of round or any other cross section with a continuous periphery, and treats its inch-pound values as the requirement, with SI figures for information. Alloy 31 seamless pipes come under the same standard but are ordered by standard pipe size and schedule.
Every lot receives one chemical analysis and one tension test. Each UNS N08031 seamless tube is then tested on its own, either hydrostatically or by a nondestructive electric test, with eddy current and ultrasonic as equal options; if your exchanger specification fixes the method, name it on the order. The hydrostatic test holds an internal pressure of 1000 psi (6.9 MPa) for at least 5 seconds, unless the allowable fiber stress for the OD and wall sets a lower pressure, and any tube that leaks is rejected.
Heat chemistry, tension results and the test applied to each tube are reported on our EN 10204 3.1 (3.2 on request) material test certificate, under the heat number used in the tube marking. If you want to witness tests at the mill, state it on the purchase order; third-party inspection is available on request.
ASTM B622 groups UNS N08031 with its low-carbon Ni-Fe-Cr-Mo-Cu alloys. Iron makes up the balance, and limits shown without a range are maximums.
UNS N0803131
| Element | ASTM B622 / ASME SB-622 Limit (%) |
|---|---|
| Ni (Nickel) | 30.0 to 32.0 |
| Cr (Chromium) | 26.0 to 28.0 |
| Mo (Molybdenum) | 6.0 to 7.0 |
| Fe (Iron) | Balance |
| C (Carbon) | 0.015 max |
| Si (Silicon) | 0.3 max |
| Mn (Manganese) | 2.0 max |
| P (Phosphorus) | 0.020 max |
| S (Sulfur) | 0.010 max |
| Cu (Copper) | 1.0 to 1.4 |
| N (Nitrogen) | 0.15 to 0.25 |
The remaining elements in the B622 table carry no requirement for this alloy, so the certificate reports the heat against the limits above.
B622 sets one row of minimums for UNS N08031, the same for tube and pipe and for every size and wall.
| Property | Value | Unit |
|---|---|---|
| Tensile Strength, min | 94 (650) | ksi (MPa) |
| Yield Strength (0.2% offset), min | 40 (276) | ksi (MPa) |
| Elongation in 2 in. (50.8 mm) or 4D, min | 40 | % |
These minimums hold for seamless nickel alloy 31 tube supplied, as B622 requires, solution annealed and descaled; an anneal under atmosphere control needs no descaling. Each tension specimen is cut after the final heat treatment and pulled in the direction of fabrication, using the full tube section whenever possible.
Alloy 31 appears under different designations on American and European drawings. ASTM B622 uses the UNS number; the W.Nr. and EN name are given for cross-reference only.
An inquiry written as 1.4562 or X1NiCrMoCu32-28-7 is quoted against UNS N08031, and the certificate reports that UNS number.
Our range for seamless WNR 1.4562 tube covers 6 mm to 219 mm OD and 0.5 mm to 20 mm wall, in lengths up to 18 m. OD and wall are held to the cold-worked tolerances below, with an average-wall order read against the average (nominal) wall column and a minimum-wall order against the minimum wall column.
| OD (D) mm | OD Tolerance (mm) | Average (Nominal) Wall | Minimum Wall |
|---|---|---|---|
| D ≤ 10 | ±0.10 | ±15.0% | +30% / 0 |
| 10 < D < 16 | ±0.13 | ±15.0% | +30% / 0 |
| 16 ≤ D ≤ 38 | ±0.19 | ±10.0% | +22% / 0 |
| 38 < D ≤ 76 | ±0.25 | ±10.0% | +22% / 0 |
| 76 < D ≤ 114 | ±0.38 | ±10.0% | +22% / 0 |
| 114 < D ≤ 152 | ±0.51 | ±12.5% | +28% / 0 |
| 152 < D ≤ 168 | ±0.64 | ±12.5% | +28% / 0 |
| 168 < D ≤ 219 | ±0.79 | ±12.5% | +28% / 0 |
Swipe sideways to see the full table.
These limits apply to individual measurements, eccentricity included. On thin-wall tube, with the wall at 3% of the OD or less, the mean OD meets the table and single readings, ovality included, may exceed it by 0.5% of the nominal OD. Above 114 mm OD with a wall over 3% of the OD, the mean OD meets the table and single readings may reach twice the table value.
| OD (mm) | Cut Length Tolerance (mm) |
|---|---|
| OD < 50.8 | +3.2 / 0 |
| OD ≥ 50.8 | +4.8 / 0 |
These limits apply to straight cut lengths up to 7.3 m.
Nickel Alloy 20 seamless tubes follow ASTM B729 alone, in the stabilized-annealed condition. Where the hydrostatic test is chosen under B729, the full length is examined for leaks while under pressure, and that standard makes a manufacturer's certification and test report mandatory on every order. A seamless Alloy 31 tube follows ASTM B622 / ASME SB-622 in the solution annealed and descaled condition, with certification when the order calls for it, and both alloys are ordered by OD and minimum or average wall. Where the design allows an austenitic stainless steel, stainless steel 904L seamless tubes are ordered to a stainless steel tube specification, so the standard named on the order changes too.
Seamless 1.4562 alloy tube goes into heat-transfer and process equipment where chloride media cause pitting and crevice attack, and into sulfuric and wet-process phosphoric acid service.
Wet-process phosphoric acid plants place this alloy in reactors, heat exchangers and evaporators, where impure acid carrying chlorides and fluorides passes through the reaction and concentration stages of production.
Sulfuric acid concentration units handle both weak and strong acid, and their process tubes are specified in this alloy to the OD and wall that each unit's design calls for.
In flue gas desulfurization scrubbers, absorber parts, heat exchangers and recirculation lines meet acidic, chloride-rich liquor, so the tubing in these sections is ordered in Alloy 31 where pitting and crevice attack occur.
Pulp and paper bleach plants run chlorine dioxide and hypochlorite circuits, and their bleach washers and heat exchangers take tubes in this alloy, each cut to the washer or bundle length.
Chemical plants fit reactors, condensers and transfer lines that handle mixed acids and halide-containing streams with this alloy, and fertilizer process plants use it for heat exchanger tubing.
Desalination equipment and offshore heat exchangers run seawater and concentrated brine through tubes in this alloy, chosen for its pitting and crevice resistance in chloride media.
Packing
Straight lengths strapped in bundles or packed in wooden cases, plastic caps on both tube ends, small-OD and thin-wall sizes in cases.
Marking
Each tube of 3/4 in. (19.0 mm) OD and larger and over 3 ft (914 mm) long carries the manufacturer name, UNS N08031, ASTM B622, heat number and nominal size; smaller or shorter tubes are marked individually or on a tag fixed to the bundle or box.
Labels
Each package states the UNS number, heat number, condition, ASTM B622, size, gross, tare and net weight, consignor and consignee and the order number.
Documents
EN 10204 3.1 (3.2 on request) material test certificate and a packing list for each bundle or case.
Terms
FOB, CIF or CFR, with the port of loading stated in the offer.
Delivery
Dispatch date confirmed with the order acknowledgment.
Seamless Alloy 31 tube is indicatively priced at USD 24 to 55 per kg. The nickel market moves that figure first and molybdenum second. Small OD and thin wall need more cold-working and annealing passes for each kilogram, which places them higher in the range, while cut length, quantity and the test plan decide where a quotation finally falls. Send the OD, wall basis, length and quantity for a firm offer.
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
We manufacture Alloy 31 seamless tubes at 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand. Our office at 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand, prepares quotations, certificates and export documents. We supply projects across Thailand and export to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
Small tube gets the tightest OD bands and the widest wall band in the table. Up to 10 mm OD the OD tolerance is ±0.10 mm and from over 10 mm to under 16 mm ±0.13 mm, both with average wall at ±15.0%. From 16 mm to 38 mm OD it is ±0.19 mm, with average wall at ±10.0%.
Order minimum wall when the design uses the thinnest permitted wall: all of the tolerance then sits on the plus side, +22% / 0 from 16 mm to 114 mm OD, so no reading falls below the figure ordered. Order average wall when the drawing gives a nominal wall, and the tolerance is split, ±10.0% in the same bands.
Yes. A higher pressure may be agreed between you and us, or applied at our option, provided the allowable fiber stress for the tube's OD and wall is not exceeded. State the required pressure on the order, or call for the nondestructive electric test if your specification prefers it.
Up to 18 m, across our 6 to 219 mm OD and 0.5 to 20 mm wall range. The +3.2 mm (under 50.8 mm OD) or +4.8 mm limit covers cut lengths up to 7.3 m; each further 3 m or part of it adds 3.2 mm, up to 12.7 mm extra, and no tube may be short.
For chemistry, a lot is one heat. For tension and other testing it is all tube of the same heat, nominal size and condition: with a batch furnace, only tubes from the same furnace charge; with a continuous furnace, one production run at the same temperature, time and speed. No lot may exceed 20 000 lb (9100 kg).
Yes, both are tube duties we supply it for. For a bundle inquiry, give the tube OD, the wall as minimum or average, the cut length from the tubesheet drawing, the tube count and any test method or pressure your specification fixes, so tolerances, length limits and the test plan are settled in the quotation.
Alloy 31 carries 6.0 to 7.0% molybdenum, 26.0 to 28.0% chromium, 1.0 to 1.4% copper and 0.15 to 0.25% nitrogen, with carbon at 0.015% maximum. Alloy 20 under ASTM B729 has 2.00 to 3.00% molybdenum, 19.00 to 21.00% chromium, 3.00 to 4.00% copper and a niobium plus tantalum addition, with carbon up to 0.07%.
Request a Quote for Alloy 31 Seamless Tubes
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