Super duplex stainless steel ASTM grades are organized by product form, not by alloy grade. Each ASTM specification covers multiple super-duplex UNS designations (S32550 Ferralium 255, S32750 Super Duplex 2507, S32760 Zeron 100). The primary spec for super duplex bar is ASTM A479; for pipe is A790; for tube is A789. Each spec defines chemistry, mechanical requirements, heat-treatment condition, marking, dimensional tolerance, and inspection / test reporting.
| ASTM Spec | Product form | Title | Common UNS |
|---|---|---|---|
| A479 | Bar, billet, shapes | Stainless Steel Bars and Shapes for Boilers and Other Pressure Vessels | S32550, S32750, S32760, S31803/S32205 |
| A276 | Bars and shapes (general) | Stainless Steel Bars and Shapes | S32550, S32750, S32760, S31803/S32205 |
| A789 | Seamless and welded tube | Seamless and Welded Ferritic/Austenitic Stainless Steel Tubing | S32550, S32750, S32760, S31803/S32205 |
| A790 | Seamless and welded pipe | Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe | S32550, S32750, S32760, S31803/S32205 |
| A815 | Wrought fittings | Wrought Ferritic/Austenitic Stainless Steel Piping Fittings | S32550, S32750, S32760 |
| A182 | Forged flanges, fittings, valves | Forged or Rolled Stainless Steel Pipe Flanges, Forged Fittings, Valves | F61 (S32550), F53 (S32760), F55 (S32750) |
| A240 | Plate, sheet, strip | Stainless Steel Plate, Sheet, and Strip for Pressure Vessels | S32550, S32750, S32760, S31803/S32205 |
ASTM A479 is the primary specification for super duplex bar supplied for pressure-vessel and pressure-boundary service. It covers hot-finished and cold-finished bar (rounds, hexagons, squares, flats), forged bar, and shapes. For super duplex grades, solution-annealed condition required: 1040 °C minimum + rapid water cool to retain ferrite within 35–55% range and avoid sigma-phase precipitation. Inspection: chemical analysis, tensile per ASTM A370, hardness per ASTM E18, intergranular corrosion test per ASTM A923 method A or C when specified, ferrite content per ASTM E562. Per-heat MTC EN 10204 type 3.2.
ASTM A789 and ASTM A790 reference identical chemistry tables for super-duplex UNS grades. Hydrostatic test per A789 paragraph 13 / A790 paragraph 14. NDE per supplementary requirements (UT per S2 or RT per S5 when specified for pipe). Same applies to Ferralium 255 pipe and Ferralium 255 tube products.
ASTM A815 covers wrought fittings (elbows, tees, reducers, caps, crosses, couplings) per ASME B16.9 buttweld and B16.11 socketweld. ASTM A182 covers forged flanges, forged fittings, and valve components per ASME B16.5 (NPS 1/2 to 24) and B16.47 (NPS 26+). Ferralium 255 designation in A182: grade F61 (vs F53 for Zeron 100, F55 for Super Duplex 2507).
European Standard equivalents: EN 10088-3 (long products), EN 10088-2 (flat products plate/sheet), EN 10222-5 (forgings), EN 10272 (bar for pressure purposes), EN 10216-5 (seamless pipe), EN 10217-7 (welded pipe). Werkstoff numbers: 1.4507 (Ferralium 255), 1.4410 (Super Duplex 2507), 1.4501 (Zeron 100), 1.4462 (Duplex 2205).
