Mooring Solutions
High Strength Steels for Offshore Mooring Chains and Accessories
Vicinay has worked together with steel mills and research centers to develop high strength steels to create chain and connectors with an ultimate tensile strength higher than 1000 MPa. These provide increased strength which offers a larger safety margin and enhanced security in challenging metocean conditions and deep waters. The weight reduction in moving to a higher grade contributes to a decreased payload of the vessel and provides easier handling and installation, becoming a real solution for the offshore industry.
Vicinay Marine has initiated and developed high strength steel grades for mooring chains and accessories providing increased strength and reduced weight for a given size. The high strength grades are as follows:
- R5, with an ultimate tensile strength of 1000 MPa.
- R6, with an ultimate tensile strength of 1100 MPa.
These grades should be considered an ideal solution for those offshore applications where moorings are shown to be risky, technologically challenging and capital intensive, such as for deepwater exploration and production, wind power or locations where in-service metocean conditions could exceed the original design parameters.
|
GRADE |
Tensile Test |
CHARPY V – NOTCH (-20ºC) |
||||||
|
Yield Point σYS (MPa) |
Tensile Strength σu (MPa) |
Elongation A5 (%) |
Reaction of Area Z (%) |
Base |
Weid |
|||
|
Single Energy (J) |
Average Energy (J) |
Single Energy (J) |
Average Energy (J) |
|||||
|
R5 |
760 |
1000 |
12 |
50 |
44 |
58 |
32 |
42 |
|
R6 |
900 |
1100 |
12 |
50 |
46 |
60 |
34 |
44 |
Recognising these challenges as opportunities to develop suitable solutions, grades R5 and R6 have been designed internally by Vicinay and technical partners, used for the manufacturing of chain and connectors specifically to meet the requirements of standard mechanical tests, fracture mechanics, fatigue and hydrogen embrittlement, so as to ensure their suitability for those offshore applications.
Vicinay has classification society approval to manufacture chain up to 220 mm diameter in R5 grade and 150 mm diameter in R6.
