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
NORSOK M-630: Material Data Sheet for Super Duplex 2507
NORSOK M-630 is the Norwegian petroleum industry standard that publishes Material Data Sheets (MDS) for piping, valve, and structural materials used on the Norwegian Continental Shelf. Each MDS pins a chemistry and a minimum mechanical envelope to a specific product form. Super duplex 2507 (UNS S32750 / Werkstoff 1.4410) is published under MDS D55 for forgings, bars and shapes and MDS D57 for seamless pipe and tube.
Norwegian operators (Equinor, Aker BP, Vaar Energi, ConocoPhillips Norway) cite NORSOK M-630 MDS designations on every line list and material requisition. TorqBolt supplies M-630 compliant 2507 with mill test certificates that quote the MDS designation alongside ASTM A479 / A790 / A182 F53 chemistry.
NORSOK M-630 Scope and Purpose
M-630 is a sector standard maintained by the Norwegian oil and gas industry (Standard Norge). Its purpose is to harmonise material requirements across operators so that mill heats can be qualified once and traded freely. Each MDS supplements the underlying ASTM or EN standard with tighter chemistry control, mandatory PREN, ferrite content limits, intentional Charpy impact testing, and supplementary corrosion testing per ASTM A923 or G48.
Super Duplex 2507 MDS Designations
| MDS | Product Form | Base Standard |
|---|---|---|
| D55 | Forgings, bars, shapes (super duplex 25Cr) | ASTM A182 F53 / A479 UNS S32750 |
| D57 | Seamless pipe and tube (super duplex 25Cr) | ASTM A790 / A789 UNS S32750 |
| D56 | Plate (super duplex 25Cr) | ASTM A240 UNS S32750 |
| D54 | Welded pipe (super duplex 25Cr) | ASTM A928 UNS S32750 |
M-630 Chemistry Tightening over ASTM
M-630 narrows the ASTM chemistry window for super duplex 2507 to enforce reliable PREN and ferrite balance. Sulphur is tightened from 0.020 (ASTM) to 0.020 max with 0.010 typical. Carbon is tightened to 0.030 max. Nitrogen is held at 0.24 to 0.32 percent (matching ASTM). Copper is capped at 0.50 max as a residual, not intentional, distinguishing the chemistry from S32760 (Zeron 100, 0.5 to 1.0 percent intentional Cu) and S32550 (Ferralium 255, 1.5 to 2.5 percent intentional Cu).
PREN Requirement
M-630 requires PREN above 40 to qualify the heat as super duplex. PREN is calculated as Cr + 3.3 x Mo + 16 x N. A typical 2507 production heat lands at PREN 41 to 43. Heats below 40 are downgraded from the super duplex classification to plain duplex and lose the M-630 D55 / D57 qualification.
Ferrite Content Window
M-630 requires ferrite content of 35 to 55 percent in the parent metal and 35 to 65 percent in welds, measured per ASTM E562 (point counting on a metallographic section). Ferrite below 35 percent indicates over-aged or mis-annealed material; ferrite above 55 percent in parent indicates incomplete austenite reformation during quench. Both extremes lose pitting resistance and toughness.
Charpy Impact Requirement
M-630 requires Charpy V-notch impact testing at minus 46 degrees Celsius. The minimum is 45 J average for three specimens, with no individual specimen below 35 J. The notch is transverse to the rolling direction. This is more demanding than ASTM A479 (which has no mandatory low-temperature impact requirement at the heat level).
Corrosion Testing
M-630 mandates ASTM A923 Method A (intermetallic phase detection by metallographic examination) on production heats. ASTM G48 Method A (ferric chloride pitting test) is invoked when the project specification requires it, with critical pitting temperature (CPT) above 35 degrees Celsius required for super duplex 2507.
Related NORSOK Standards
- NORSOK M-001: material selection
- NORSOK M-501: surface preparation and protective coating
- NORSOK M-650: qualification of manufacturers (QTR)
- NORSOK M-CR-630: linked corrosion-resistant alloys catalogue
- NORSOK L-002: piping system layout
Cross-Reference: M-630 to ASTM and EN
| NORSOK MDS | ASTM Equivalent | EN Equivalent |
|---|---|---|
| D55 (forgings, bars) | A182 F53 / A479 | EN 10222-5 / EN 10272 (1.4410) |
| D57 (seamless pipe / tube) | A790 / A789 | EN 10216-5 (1.4410) |
| D56 (plate) | A240 UNS S32750 | EN 10028-7 (1.4410) |
NORSOK M-630 Frequently Asked Questions
What MDS designation applies to super duplex 2507 forgings?
D55. NORSOK M-630 MDS D55 covers super duplex 25Cr forgings, bars, and shapes including UNS S32750. The base ASTM standard is A182 F53 (forgings) or A479 (bar). M-630 D55 supplements the ASTM chemistry with tighter sulphur, mandatory ferrite measurement, mandatory low-temperature Charpy, and ASTM A923 intermetallic test.
What MDS designation applies to super duplex 2507 seamless pipe?
D57. NORSOK M-630 MDS D57 covers super duplex 25Cr seamless pipe and tube including UNS S32750. The base ASTM standard is A790 (pipe) or A789 (tube). The supplementary requirements parallel D55: ferrite measurement, low-temperature Charpy, A923 intermetallic test.
What is the PREN minimum under NORSOK M-630 for super duplex?
PREN above 40, calculated as Cr + 3.3 x Mo + 16 x N. Production heats of UNS S32750 typically land at PREN 41 to 43. A heat with PREN below 40 is downgraded to duplex and loses M-630 super duplex qualification.
What ferrite range does M-630 require?
Parent metal: 35 to 55 percent ferrite. Welds: 35 to 65 percent. Measured per ASTM E562 by point counting on a polished and etched metallographic section. Mill heats outside this window are rejected.
What Charpy impact test is required by M-630?
Charpy V-notch at minus 46 degrees Celsius. Minimum 45 J average of three specimens, no individual below 35 J. Transverse notch orientation. Stricter than ASTM A479 (which has no mandatory low-temperature impact at heat level).
Does M-630 apply outside Norway?
Yes. M-630 is widely cited by international operators for super duplex piping on offshore platforms, FPSOs, and subsea systems regardless of project location. Brazilian, Australian, Middle East and Gulf of Mexico projects routinely specify NORSOK MDS designations alongside ASTM.
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