Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175 / ISO 15156-2
- NORSOK M-650 Qualified
- API 6A Certified
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
ASTM A815: Super Duplex 2507 Wrought Pipe Fittings (WP-S32750)
ASTM A815 is the standard specification for wrought ferritic, ferritic-austenitic, and martensitic stainless steel piping fittings. Within A815, super duplex 2507 is registered as WP-S32750 (Wrought Piping UNS S32750). The standard covers buttweld fittings such as elbows, tees, reducers, caps, and stub ends, dimensioned per ASME B16.9 and B16.11. The European parallel is EN 10253-4 in Werkstoff 1.4410.
TorqBolt supplies A815 WP-S32750 buttweld fittings across NPS 1/2 to NPS 24 in matching ASME B16.9 dimensions, with mill test certificates that record chemistry, mechanical properties, ferrite content, and heat treatment.
ASTM A815 Scope
A815 covers wrought (forged or rolled and machined) piping fittings of duplex, super duplex, ferritic, and martensitic stainless steels. Fittings are designated WP- followed by the UNS number (e.g., WP-S32750 for super duplex 2507). The standard governs chemistry, mechanical properties, heat treatment, dimensions (per B16.9 and B16.11), marking, and traceability. Hydrostatic testing is per project specification.
A815 Designations for Super Duplex
| Designation | Alloy |
|---|---|
| WP-S32750 | Super Duplex 2507 (UNS S32750) |
| WP-S32760 | Zeron 100 (UNS S32760) |
| WP-S31803 | Duplex 2205 (UNS S31803) |
| WP-S32550 | Ferralium 255 (UNS S32550) |
A purchase order calling for WP-S32750 must be filled with super duplex 2507 (UNS S32750). The WP- designations are not interchangeable; each maps to a specific UNS number with distinct chemistry.
Chemistry for WP-S32750
| Element | Min % | Max % |
|---|---|---|
| Carbon (C) | (no min) | 0.030 |
| Chromium (Cr) | 24.0 | 26.0 |
| Nickel (Ni) | 6.0 | 8.0 |
| Molybdenum (Mo) | 3.0 | 5.0 |
| Nitrogen (N) | 0.24 | 0.32 |
| Manganese (Mn) | (no min) | 1.20 |
| Silicon (Si) | (no min) | 0.80 |
| Phosphorus (P) | (no min) | 0.035 |
| Sulfur (S) | (no min) | 0.020 |
| Copper (Cu) | (no min) | 0.50 max, residual, not intentional |
Mechanical Requirements
| Property | Minimum |
|---|---|
| Tensile strength | 800 MPa (116 ksi) |
| Yield strength (0.2 percent) | 550 MPa (80 ksi) |
| Elongation in 50 mm | 15 percent |
| Hardness | 32 HRC max |
Heat Treatment
Solution annealing at 1040 to 1100 degrees Celsius followed by rapid water quench. Buttweld fittings produced by hot-forming (e.g., elbows, tees) are solution annealed after forming. Cold-formed fittings are solution annealed after forming. Quench design must drive the section through the 600 to 1000 degrees Celsius critical band rapidly to suppress sigma-phase precipitation.
Fitting Forms under A815
- Long radius elbows (45 deg, 90 deg) per ASME B16.9
- Short radius elbows per ASME B16.9
- Tees equal and reducing per ASME B16.9
- Reducers concentric and eccentric per ASME B16.9
- Caps per ASME B16.9
- Stub ends long and short pattern per ASME B16.9
- Forged threaded and socket weld fittings per ASME B16.11 (smaller sizes)
Required Tests
| Test | Method / Acceptance |
|---|---|
| Chemistry | Per ASTM E1086 family |
| Tensile | ASTM A370 |
| Hardness | HRC / HBW |
| Ferrite (S52) | ASTM E562 point count, 35 to 55 percent typical |
| Intermetallic (S58) | ASTM A923 Method A |
| Pitting (S59) | ASTM G48 Method A, CPT above 35 degrees Celsius |
| NDE on hot-formed fittings | MT or PT on body and weld attach surfaces |
| Hydrostatic (project) | Per project specification |
Related Standards
- ASTM A182 F53: forging / flange / forged-fitting spec
- ASTM A479: bar spec
- ASTM A789: tube spec
- ASTM A790: pipe spec
- ASME B16.9: factory-made wrought buttweld fittings dimensions
- ASME B16.11: forged fittings (socket weld and threaded)
- EN 10253-4: European wrought stainless fitting spec for Werkstoff 1.4410
- NORSOK M-630: MDS D55 (forgings, fittings)
- NACE MR0175 / ISO 15156-3: sour service requirements
ASTM A815 Frequently Asked Questions
What does ASTM A815 cover for super duplex 2507?
A815 specifies wrought super duplex 2507 buttweld fittings under the designation WP-S32750. Includes long radius and short radius elbows, equal and reducing tees, concentric and eccentric reducers, caps, and stub ends, dimensioned per ASME B16.9.
What does the WP-S32750 designation mean?
WP stands for Wrought Piping; S32750 is the UNS number for super duplex 2507. The full designation specifies the alloy and the product class. WP-S32750 is not interchangeable with WP-S32760 (Zeron 100) or WP-S31803 (duplex 2205); each is a distinct alloy.
What heat treatment applies to A815 fittings?
Solution annealing at 1040 to 1100 degrees Celsius followed by rapid water quench, performed after hot or cold forming. Quench design is critical for heavy sections to drive the centre through the 600 to 1000 degrees Celsius critical band fast enough to suppress sigma-phase precipitation.
Does A815 require ferrite control?
Supplementary requirement S52 invokes ferrite measurement per ASTM E562. NORSOK M-630 D55 supplements with 35 to 55 percent parent metal ferrite. NACE MR0175 widens to 35 to 65 percent for sour service. Mill heats outside the window are not admissible.
Are A815 fittings hydrostatically tested?
Hydrostatic testing is per project specification rather than mandatory in A815. NDE (MT or PT) on body and weld preparation surfaces is typical. The fitting is hydrostatic-tested as part of the assembled piping system after installation.
Can WP-S32750 substitute WP-S32760?
No. The two are different alloys. WP-S32750 (super duplex 2507) has copper as a residual (0.50 max). WP-S32760 (Zeron 100) has 0.5 to 1.0 percent intentional copper plus tungsten. Substitution requires customer specification approval and re-traceable purchase order amendment.
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