ASME SA789 UNS S33207 Super Duplex Stainless Steel Tube

ASME SA-789 / SA-789M lists UNS S33207 among seamless and welded duplex tubing grades in Section II Part A. The title word on this series is Super Duplex, but like S32707 this grade is commonly marketed as hyper duplex for PREN well above 48. Chemistry: chromium 29.0–33.0%, nickel 6.0–9.0%, molybdenum 3.0–5.0%, nitrogen 0.40–0.60%, copper 1.0% max, carbon ≤0.030%.

SHH STEEL can produce and supply ASME SA789 UNS S33207 super duplex (hyper duplex class) stainless steel tube in seamless and welded (no filler metal) forms, with EN 10204 3.1 MTCs reporting the extreme Cr/N bands, wall-dependent tensile floors up to 138/112 ksi, and Table 2 heat treatment at 1905–2085 °F with rapid water (or other) cooling. Dual marking is available when requested.

Sister hyper option: SA789 S32707. Mainstream super duplex: SA789 S32750, SA789 S32760. Standard duplex: SA789 S32205. Plate: A240 / SA240. Hub: SA789/SA789M. Keep the ASME designation on Code purchase orders even when dual ASTM marking is also requested for documentation convenience.

Table 1 of ASME SA-789 fixes the heat analysis for S33207. Product analysis applies when Section 8 or the purchase order invokes it through A1016/A1016M, using A480/A480M tolerances. SHH STEEL reports actual ladle values on the EN 10204 3.1 MTC for every heat.

Mid-range PREN with Cr ≈31, Mo ≈4.0, N ≈0.50 gives PREN ≈ 52.2 — deep in the hyper-duplex band. Nitrogen 0.40–0.60% and chromium up to 33% drive that number. SA-789 does not define “hyper duplex” or publish a PREN footnote for S33207; the label is explained here for buyer clarity.

Table 4 sets tensile and hardness requirements for S33207 after final heat treatment. Lot sampling follows Section 9. Mechanical properties do not apply below 1/8 in. [3.2 mm] OD or 0.015 in. [0.4 mm] wall.

Table 4 splits by wall: under 0.157 in. [4 mm] — tensile 138 ksi [950 MPa] min, yield 112 ksi [770 MPa] min; at/above 0.157 in. — tensile 123 ksi [850 MPa] min, yield 101 ksi [700 MPa] min; elongation 15% min and hardness max 336 HBW / 36 HRC / 330 HV on both rows. Source: ASME BPVC.II.A-2023 SA-789 Table 4.

ASME SA-789 allows S33207 as seamless tube or as welded tube made with no filler metal. After welding, the finished tube is heat-treated under Table 2, and marking must state the manufacture route with average or minimum wall so receiving can match each length to the purchase order and MTC.

Seamless lots take flaring to at least 10% ID expansion on one end of one tube per lot. Welded lots take flange testing plus reverse flattening on each 1500 ft [450 m] of finished tubing. Tension and hardness apply to both routes. SHH STEEL produces both SA789 S33207 routes and records them on stencil and EN 10204 3.1 MTC.

Order ASME SA789 S33207 by OD × wall (average unless minimum is specified) and length in tube / BWG language, not B36.19 pipe schedules first. Table 5 sets OD-group tolerances; clause 12.2 covers thin-wall ovality.

Source: ASME BPVC.II.A-2023 SA-789 Table 5. SHH STEEL quotes average-versus-minimum wall explicitly on every S33207 enquiry. Write average or minimum wall on every line item so Table 5 percentage bands are unambiguous at receiving.

ASME SA-789 UNS S33207 is the governing tubing designation for this article. Approximate wrought names are chemistry-family hints, not automatic Code substitutes on an SA-789 mill test certificate. Confirm the product standard and tensile row before accepting a commercial nickname on the certificate.

Spell the UNS number and ASME SA789 on the purchase order rather than relying on a shop nickname alone. Confirm the product standard and tensile row before accepting a commercial nickname on the certificate.

Table 2 requires S33207 solution treatment at 1905–2085 °F [1040–1140 °C] followed by rapid cooling in water or by other means. Table 2 requires 1905–2085 °F [1040–1140 °C] with rapid cooling in water or by other means — water quench emphasis suits this extreme alloy content.

Seamless tubes may be quenched after hot forming when temperature is not below the minimum solution-treatment temperature. Skipping or under-cooling risks intermetallics and undermines corrosion performance. SHH STEEL delivers SA789 S33207 only heat-treated per Table 2, with the record on the MTC.

Hyper duplex S33207 is aimed at the most severe chloride environments where even S32750 is insufficient, with estimated PREN near 52.2. Fabrication risk is high: very high Cr/Mo/N promote sigma if cooling is slow. Specify only with experienced mills and fabricators.

Observe SA-789 embrittlement warnings and 475 °C / sigma practice with strict thermal control. Materials review should precede any attempt to stretch this grade outside its PREN and temperature envelope.

S33207 tube is for hyper-duplex chloride service and extreme strength when the datasheet names this UNS or a PREN well above 48. Match fluid chemistry and temperature to the PREN estimate and Table 4 floors before freezing the bill of materials.

Compare SA789 S32707 for cobalt-bearing hyper duplex; step down to SA789 S32750 when PREN ≥41 is enough. Match fluid chemistry and temperature to the PREN estimate and Table 4 floors before freezing the bill of materials.

Welding S33207 requires hyper-duplex qualified procedures — not 2205 or casual 2507 PQRs. Heat input, interpass, and cooling rate control are non-negotiable. Mill welded SA-789 product remains autogenous with no filler in the seam.

SHH STEEL can discuss filler families; the fabricator owns WPS/PQR under the applicable Code. Procedure qualification on the actual UNS avoids ferrite and sigma surprises in the heat-affected zone.

Standard delivery for SA789 S33207 is heat-treated and descaled/pickled per Section 13, free of excessive mill scale. Bright anneal or Ra-controlled finishes are agreement items that must appear on the order.

SHH STEEL quotes special finishes against the written enquiry rather than assuming them with the grade stamp for S33207. Call any Ra or bright requirement out on the enquiry so mill routing can include it before the heat is reserved.

Testing covers Table 1 chemistry, Table 4 tension and hardness, flare or flange tests by route, reverse flattening for welded tube, and hydro or NDE on each length using duplex hydrostatic factor 64000 (441.2). Manufacturer chooses hydro versus NDE unless the PO locks the method.

Marking shows seamless or welded and wall basis. SHH STEEL 3.1 MTCs tie heat, chemistry, mechanicals, heat treatment, and test method to each length for receiving clearance. Receiving teams should verify hydro-versus-NDE against the purchase order before releasing tube to fabrication.

S33207 tube ships from SHH STEEL in tagged bundles with end protection matched to length. Tags repeat ASME SA789, grade, route, OD × wall, heat number, and PO reference for export or domestic delivery.

Wrapped bundles or wooden cases are available for bright or small-bore material. Incoterms and MTC flow follow the order acknowledgment. Keep bundle tags legible after ocean transit so port and site receiving can proceed without remarking every length.

SHH STEEL produces and supplies ASME SA789 UNS S33207 as manufactured hyper-class super-duplex Code Book tube, reporting the high Cr/N chemistry and wall-dependent tensile floors on the EN 10204 3.1 MTC.

We will not substitute SA789 S32750 against an S33207 order. Dual marking is available on request. Honest sister-grade advice protects Code stamp integrity when a different UNS would fit the corrosion envelope better.

SHH STEEL can produce and supply ASME SA789 UNS S33207 against the edition, route, and finish on your enquiry. Capability and Stock / Available sizes follow. Clear enquiry data on OD, wall, and route shortens quotation turnaround for export and domestic Code jobs.

Stock / Available sizes — Regular enquiry bands include OD about 12.7–50.8 mm with common BWG / metric walls; larger Table 5 groups by agreement. Cut lengths on request. Send OD × wall, route, and quantity — no invented tonnage lists.

List ASME SA789 UNS S33207, seamless or welded, OD × wall, wall basis, length, and quantity on the enquiry. Clear enquiry data on OD, wall, and route shortens quotation turnaround for export and domestic Code jobs.

ASME SA789 UNS S33207 is supplied by SHH STEEL as seamless and welded (no filler metal) super duplex tubing under the Section II Part A Code Book product standard, heat-treated per Table 2, tested per Section 9, and certified on EN 10204 3.1 MTCs. Confirm OD × wall, wall basis, manufacture route, and any dual SA-789/A789 marking on the purchase order so stencil and certificate match the datasheet. For technical follow-up, contact admin@steelspecs.com.