ASTM A789 UNS S32003 Lean Duplex Stainless Steel Tube

ASTM A789 / A789M is the product specification for seamless and welded ferritic/austenitic stainless steel tubing for general corrosion service, with particular emphasis on resistance to stress corrosion cracking. UNS S32003 is a lean duplex with heat limits of carbon ≤0.030%, chromium 19.5–22.5%, nickel 3.0–4.0%, molybdenum 1.50–2.00%, and nitrogen 0.14–0.20% in A789/A789M-24 Table 1. Unlike ultra-lean grades that only allow Mo as a residual maximum, S32003 carries a real Mo working range — enough to lift PREN above the lowest lean band while still sitting below standard 2205-class alloy cost and nickel content.

SHH STEEL can produce and supply ASTM A789 UNS S32003 lean duplex stainless steel tube as seamless and welded product (no filler metal on welded) in typical heat-exchanger and process OD × wall / BWG sizes, with EN 10204 3.1 mill test certificates. Dual A789/SA789 marking is available only when both names are on the purchase order. See the A789/A789M hub.

Market names include AL 2003 and lean duplex S32003; they do not replace the UNS on the stencil. Compare with lower-Mo lean A789 S32001 and A789 S32101, and with standard duplex A789 S32205 when full 3% Mo is required. Plate: A240.

Heat analysis must meet A789/A789M-24 Table 1. Product analysis follows A480/A480M annex tolerances when ordered.

Mid-range PREN = Cr + 3.3Mo + 16N at Cr 21, Mo 1.75, N 0.17 is about PREN ≈ 29–30 — upper lean / lower standard duplex transition. Nickel at 3.0–4.0% is still lean versus S32205’s 4.5–6.5%, which is why the QUEUE titles this grade Lean Duplex even though Mo is purposeful. Nitrogen 0.14–0.20% matches the modern 2205 nitrogen floor and helps austenite balance.

Tensile and hardness floors are from older A789 Table 4 reprints (not in the public -24 sample). A footnote in those copies notes that prior to A789/A789M–04 the values for S32003 were 90 ksi tensile and 65 ksi yield — the current older-table figures below are the post-04 set.

At 100/70 ksi, S32003’s older-table floors actually match or exceed several standard duplex entries — lean in nickel, not lean in strength. Reconfirm on the PO edition before design lock-in.

A789 Section 5 allows seamless or welded manufacture with no filler metal added. Seamless S32003 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 S32003 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 S32003 is marketed as AL 2003 / lean duplex 2003 in some mill literature. Confirm UNS on every order because lean duplex trade names are not standardized globally.

Dual A789/SA789 on request. Step up to A789 S32205 when 3% Mo is mandatory. Hub: A789/A789M.

A789/A789M-24 Table 2 lists UNS S32003 at 1850–2050 °F [1010–1120 °C] with rapid cooling in water or by other means. Direct quench after hot forming is allowed for seamless tube at or above the minimum solution temperature.

Mo at 1.5–2.0% means sigma risk is real if cooling is sluggish through ~700–1000 °C. A789 also warns about embrittlement after prolonged elevated-temperature use, including 475 °C (885 °F) ferrite embrittlement. SHH STEEL supplies S32003 solution-annealed and quenched per Table 2.

S32003 sits between ultra-lean grades such as A789 S32001 and standard duplex A789 S32205 on chloride pitting screens. Mid-range PREN ≈29–30 and purposeful Mo give better crevice margin than Mo-max-only lean grades, while nickel stays lean.

It is still not a seawater crevice substitute for A789 S32750. Match heat-certificate PREN and project chloride limits; do not assume “lean duplex” means interchangeable across S32001/S32003/S32101.

Used in process water and mild chloride heat-exchanger tube, chemical coolers, desalination pretreatment, and structural or pressure tube where duplex yield strength and better-than-316 SCC resistance are needed at lean nickel cost. Projects that want more Mo than S32101 but not full 2205 often land here.

SHH STEEL produces and supplies A789 S32003 and can quote A789 S32205 beside it when the corrosion review is still open.

Autogenous welded tube must meet parent anneal and mechanicals. Fabrication fillers are typically lean or 2209-type duplex consumables qualified for the base metal, with controlled heat input. Re-anneal after heavy hot work when required; avoid sigma and 475 °C soaks during coating cure 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 S32003 lean duplex tube as a Shanghai manufacturer-exporter — coordinating the Mo-bearing lean chemistry, tube making, anneal, test, and EN 10204 3.1 documents to the PO. That is production capability, not a trader-only listing.

We help buyers place S32003 correctly between ultra-lean options and A789 S32205 so the Mo level on the certificate matches the corrosion intent.

SHH STEEL can produce and supply ASTM A789 UNS S32003 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 S32003 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 S32001, A789 S32101, and A789 S32205 can be quoted on the same enquiry when the project mixes duplex classes.

ASTM A789 UNS S32003 is a Mo-bearing lean duplex stainless tube grade that sits between ultra-lean Mn duplex and full 2205-class material. SHH STEEL produces and supplies seamless and welded S32003 to the A789 anneal and test regime with EN 10204 3.1 documentation. For sizes or a comparison with A789 S32205, contact admin@steelspecs.com.