Supplying Super Duplex Stainless Steel Piping Systems for Norway’s North Sea Deep-Water Oil & Gas Fields

To meet the rigorous demands of the North Sea project, we provided a total solution covering everything from specialized metallurgy to finished product:

A. Precision Control of Chemical Composition & PREN Values

To ensure ultimate corrosion resistance, we strictly controlled the content of Chromium (Cr), Molybdenum (Mo), and Nitrogen (N). We guaranteed a Pitting Resistance Equivalent Number (PREN) stable above 42 (exceeding the industry standard of 40). This allowed the material to achieve zero corrosion during 72-hour Ferric Chloride cycle testing.

B. Optimized Phase Balance Heat Treatment

The performance of Super Duplex steel depends on the delicate balance between Ferrite and Austenite (50:50). We utilized precise solution annealing processes to prevent the precipitation of harmful intermetallic phases (such as the Sigma phase). Each batch underwent metallographic examination to ensure a perfect phase balance, resulting in optimal mechanical strength.

C. Charpy V-Notch Testing at -50°C

We performed additional Charpy V-notch impact testing at -50°C for every heat number. The results significantly exceeded the requirements of the Norwegian petroleum industry standard (NORSOK M-630), ensuring structural stability even in the frigid depths of the subsea environment.

D. Digital Traceability & NORSOK Compliance

The Norwegian market has the world’s strictest documentation requirements. We provided a complete set of Mill Test Certificates (MTCs) complying with NORSOK M-650 qualification, including heat treatment curves, intergranular corrosion test reports, and third-party physical property verifications.