ASTM A789 UNS S32202 Lean Duplex Stainless Steel Tube

ASTM A789 / A789M covers seamless and welded ferritic/austenitic stainless steel tubing for general corrosion service with particular emphasis on stress corrosion cracking resistance. UNS S32202 is a lean duplex listed in A789/A789M-24 Table 1 with carbon ≤0.030%, chromium 21.5–24.0%, nickel 1.00–2.80%, molybdenum 0.45% max, and nitrogen 0.18–0.26%. Elevated nitrogen and chromium do the lean work that nickel and molybdenum would do in a standard duplex, which is why this page uses the Lean Duplex title word from the QUEUE.

SHH STEEL can produce and supply ASTM A789 UNS S32202 lean duplex stainless steel tube as seamless and welded product (welded without filler metal) in typical heat-exchanger and process OD × wall / BWG sizes, with EN 10204 3.1 mill test certificates. Dual A789/SA789 marking only when both standards are on the purchase order. Hub: A789/A789M.

EN 1.4062 and S32202 lean duplex are common cross-references; they do not replace the UNS on the stencil. Compare with A789 S32101, A789 S32304, and standard duplex A789 S32205. Plate: A240.

Heat analysis must meet A789/A789M-24 Table 1. Sulfur is tightly capped at 0.010% max — lower than many sister grades.

Mid-range PREN = Cr + 3.3Mo + 16N at Cr 22.75, Mo 0.20, N 0.22 is about PREN ≈ 27 — upper lean band. Molybdenum is a maximum only (0.45%), so some heats contribute almost no Mo term to PREN; nitrogen at 0.18–0.26% is the intentional lean PREN driver. Do not assume a Mo-bearing crevice margin from the duplex label alone.

Older A789 Table 4 copies (not in the public -24 sample) list the following for S32202; reconfirm on the PO edition.

Elongation at 30% matches other lean entries such as S32101’s floor and exceeds the 25% used for many standard duplex grades in those same copies. Yield at 65 ksi still roughly doubles annealed 304/316.

A789 Section 5 allows seamless or welded manufacture with no filler metal added. Seamless S32202 tube is typically hot-finished then cold-drawn to final OD and wall; welded tube is roll-formed from matching strip and autogenously welded, then usually cold-worked and re-annealed so the seam meets parent-metal heat treatment and mechanical floors.

Seamless lots take a flaring test (minimum 10% inside-diameter expansion); welded lots take a flange test plus a reverse flattening test on a specimen from each 1500 ft [450 m] of finished tubing. Tension and hardness sampling apply to both routes. SHH STEEL produces and supplies both seamless and welded A789 S32202 against the route named on the enquiry, with EN 10204 3.1 coverage of chemistry and mechanicals.

Average wall is the default under A789; specify minimum wall on the order when that is the design basis. Outside diameter and wall are ordered as tube sizes (metric or inch OD × wall / BWG). General dimensional requirements sit in Specification A1016/A1016M unless A789 states otherwise.

When converting a pipe schedule into tube wall, state clearly whether acceptance is average or minimum wall — the two are not interchangeable on the mill ticket. SHH STEEL confirms OD × wall, length, and finish before the heat is reserved.

UNS S32202 aligns with EN 1.4062 (X2CrNiN22-2) in public duplex composition tables.

Dual A789/SA789 on request. Hub: A789/A789M.

A789/A789M-24 Table 2 lists UNS S32202 at 1870–1975 °F [1020–1080 °C] with rapid cooling in water or by other means. Seamless tube may be quenched directly after hot forming at or above the minimum solution temperature.

Keep quench practice tight to limit intermetallics; A789 warns about embrittlement after prolonged elevated-temperature use, including 475 °C (885 °F) ferrite embrittlement. SHH STEEL supplies S32202 solution-annealed and quenched per Table 2.

S32202 targets chloride SCC resistance and lean duplex strength where Mo is not the corrosion design driver. Mid-range PREN ≈27 sits with other lean grades and below A789 S32205.

Prefer A789 S32003 or A789 S32205 when a guaranteed Mo addition is written into the corrosion spec. Prefer S32202 when the datasheet freezes this UNS / 1.4062 chemistry.

Water and light process heat-exchanger tube, structural and pressure tube replacing heavier austenitics, and projects that already freeze EN 1.4062 / S32202. Not a seawater crevice grade.

SHH STEEL produces and supplies A789 S32202 and can quote sister lean or standard duplex grades on the same enquiry.

Autogenous welded tube must meet parent anneal and mechanicals. Fabrication fillers are typically lean duplex consumables with controlled heat input. Re-anneal after heavy hot work when required; avoid sigma and 475 °C bake soaks unless qualified.

Standard delivery is solution-annealed and pickled (or otherwise descaled) so the passive film can form uniformly. Bright-annealed or lightly polished OD/ID finishes are available by agreement when the exchanger or hygienic duty needs a smoother bore. Passivation after pickling or after fabrication welding is good practice in chloride service; remove carbon-steel tooling contamination before commissioning. SHH STEEL states the finish route on the quotation and on the MTC.

Each A789 tube takes either a nondestructive electric test or a hydrostatic test. Mechanical sampling covers tension, hardness, and flaring for seamless or flange plus reverse flattening for welded, with full heat analysis on the mill test certificate. Product analysis and supplementary corrosion or ferrite tests are added when the purchase order asks for them. SHH STEEL issues EN 10204 3.1 as standard and arranges third-party inspection / 3.2 when the enquiry names an agency, with lot identity per A789 Notes 1 and 2.

Tube is typically packed in hexagonal bundles or plywood cases with end protectors and waterproof wrapping for ocean freight, with bundle tags repeating heat number, size, and standard. Cut-to-length exchanger tube may be boxed by length group; U-bends travel in purpose-built crates when ordered. SHH STEEL ships FOB, CFR, CIF, or EXW under the Incoterm on the order, with commercial invoice, packing list, and the EN 10204 3.1 or 3.2 certificate set.

SHH STEEL produces and supplies ASTM A789 UNS S32202 lean duplex tube from Shanghai — coordinating low-Ni / high-N lean chemistry, tube making, anneal, test, and EN 10204 3.1 documents to the PO. Production capability, not trader-only.

We help buyers confirm whether Mo-max-only S32202 matches the corrosion intent or whether A789 S32003 / A789 S32205 is the safer call.

SHH STEEL can produce and supply ASTM A789 UNS S32202 against the edition, size, and finish route named on your enquiry. The capability table below summarizes what we regularly quote, followed by the Stock / Available sizes map.

Stock / Available sizes

SHH STEEL quotes S32202 tube against a practical production-and-stock enquiry range rather than a frozen warehouse SKU list with published tonnages. Availability of any single line on a given week depends on mill drawing and inbound schedule — treat the table as a supply map for enquiry.

When you send an enquiry, include the ASTM edition if known, seamless or welded, OD × wall (avg or min), length, finish, test extras, and destination port. Sister grades such as A789 S32101, A789 S32304, and A789 S32205 can be quoted on the same enquiry when the project mixes duplex classes.

ASTM A789 UNS S32202 is a low-nickel, nitrogen-strengthened lean duplex stainless tube grade for general corrosion and SCC-resistant service at lean alloy cost. SHH STEEL produces and supplies seamless and welded S32202 with EN 10204 3.1 documentation. Contact admin@steelspecs.com for sizes or a comparison with A789 S32205.