Forged stainless components · Covers super duplex (F55), duplex (F51), austenitic, ferritic, martensitic, precipitation-hardening grades · ASME B16.5 / B16.47 / B16.34 dimensional
ASTM A182 is the umbrella specification for forged or rolled alloy and stainless steel pipe flanges, fittings, valves, and parts intended for high-temperature service. The standard spans austenitic, ferritic, martensitic, super duplex, duplex, and precipitation-hardening grades, identified by F-prefix designations: F22 (Cr-Mo), F304 / F316 (austenitic), F44 (6Mo), F51 / F60 (duplex 2205), F55 (super duplex UNS S32760), F53 (super duplex UNS S32750). The specification governs chemistry, mechanical properties, heat treatment, supplementary requirements (NDT, hardness, low-temperature impact), and certificate type per EN 10204.
For super duplex services where chloride, sulphide, and elevated temperature stack against the joint, F55 is the working grade. The forging route gives a finer, more uniform microstructure than the matching cast equivalents (A890 / A995), with ferrite-austenite balance held in the 35-55% window through post-forge solution annealing and rapid water quench.
| A182 designation | UNS | EN / Werkstoff | Family | Typical service |
|---|---|---|---|---|
| F55 | S32760 | 1.4501 | Super duplex (25Cr-W-Cu) | FPSO topside, subsea manifolds, NORSOK M-650, NACE MR0175 sour-service |
| F53 | S32750 | 1.4410 | Super duplex (SAF 2507 family) | Same envelope as F55, no W addition |
| F51 / F60 | S31803 / S32205 | 1.4462 | Duplex 2205 | Mid-tier seawater bolting, FPSO process piping |
| F44 | S31254 | 1.4547 | 6Mo super austenitic (254 SMO) | Crevice-corrosion service, FGD, desalination |
| F304L / F316L | S30403 / S31603 | 1.4307 / 1.4404 | Austenitic stainless | General process, low-chloride service |
Hot-forging cycles take F55 through 1100-1280°C and back. The cooldown crosses the sigma-phase precipitation window (600-1000°C); without a controlled solution-anneal cycle (1100-1140°C soak + water quench), brittle sigma + chi + Cr2N + M23C6 intermetallics nucleate in the ferrite phase and destroy the corrosion + impact envelope. ASTM A182 enforces this through the qualification + production heat treat clause, and TorqBolt witnesses it via ASTM A923 Method C (Charpy at room temperature, 60 J minimum) on every heat lot. Witness coupons from the same heat-treat batch ship with the certificate.
Send the spec (component + size + ASME class + grade + supplementary requirements + MDS / project spec to comply with + quantity + destination port) to info@torqbolt.com or +91-22-66157017 / WhatsApp. Cross-reference: Zeron 100 forgings hub, FG fastener-grade cornerstone, A276 source bar specification.
