Specification reference for forged super duplex flanges, fittings, and valve components in F61 grade
ASTM A182 / A182M is the umbrella specification that covers forged or rolled stainless steel pipe flanges, forged fittings, and valves intended for high-temperature pressure-containing service. Super duplex grades enter the standard via the F-series grade designations: F60 (UNS S32205, standard duplex 22Cr), F61 (UNS S32550, Ferralium 255), F53 (UNS S32750, super duplex 2507), and F55 (UNS S32760, Zeron 100). The F61 grade designation matches Ferralium 255 chemistry: 24.0 to 27.0% Cr, 4.5 to 6.5% Ni, 2.9 to 3.9% Mo, 1.5 to 2.5% Cu, 0.10 to 0.25% N. The standard requires solution-anneal at 1040 to 1120 °C with rapid quench, hardness ≤ 32 HRC for NACE MR0175 sour-service, ferrite content within 35 to 55% per ASTM E562 point count, and tensile properties matching the parent ASTM A479 bar specification.
| Standard | Product | Form |
|---|---|---|
| ASTM A182 | Forged or rolled flanges, forged fittings, valve components | Forged |
| ASTM A479 | Bar and shapes for pressure-vessel service | Bar (the upstream feedstock for A182) |
| ASTM A276 | Bar and shapes for general service | Bar |
| ASTM A789 | Seamless and welded tubing | Tube |
| ASTM A790 | Seamless and welded pipe | Pipe |
| ASTM A815 | Wrought ferritic / ferritic-austenitic / martensitic fittings | Wrought fitting (cold or hot formed from pipe / tube / plate) |
| ASTM A240 | Plate, sheet, strip for pressure vessels | Plate / sheet |
A182 paragraph 8 mandates per-heat verification of chemistry, paragraph 9 mandates per-heat tensile and hardness, paragraph 11 mandates microstructure and ferrite-content acceptance, paragraph 12 covers supplementary requirements including S52 (Charpy V-notch), S58 (intergranular corrosion per ASTM A262 method E), and S5 (NDE). For NORSOK M-650 qualified product the supplementary requirements are typically S52 + S58 + S5 + S60 (NACE MR0175 conformance documentation). For sour-service piping per ISO 15156-3 Table A.10 the hardness traverse must include three locations per piece, and the ferrite-content point count must include both transverse and longitudinal sections for forgings above 25 mm cross-section.
