Why use super duplex stainless steel 32760 (F55/1.4501/MDS D59 & D60)?
Super duplex stainless steel is a material with enhanced corrosion resistance categorized by its PREN (>40) compared to duplex stainless steels which have a PREN of around 35.
Super duplex, relative to other stainless steels gives:
- High resistance to pitting and crevice corrosion
- High resistance to stress corrosion cracking
- High yield and tensile strength properties
especially in seawater and other chloride containing environments. Super duplex stainless steel is used extensively for offshore oil & gas applications.
NORSOK M650 sets out to ‘establish a set of qualification requirements to verify that the manufacturer has sufficient competence and experience in relevant material grades, and the necessary facilities and equipment to manufacture the material grades/products with acceptable properties.’
Hydrobolt is NORSOK M650 approved to supply super duplex stainless steel fasteners to NORSOK M630 MDS D59 & D60. To become NORSOK approved, a qualifying company has to monitor the qualification exercise. Hydrobolt’s qualifying company was Aker Solutions, one of the world’s leading providers of product, systems and services to the oil & gas industry, and a major contractor to Statoil.
A NORSOK approval qualified by Aker Solutions is rated as second to none.
TR2000 is Statoil’s approved manufacturer list (AML) and centres around NORSOK approved companies. Hence, Hydrobolt has been added to Statoil TR2000 database to supply both strain hardened (D59) and solution treated (D60) super duplex stainless steel bolting to its projects, in particular Johan Sverdrup, one of the largest oilfield discoveries on the Norwegian Continental Shelf in the last 50 years.