Use of a steel composition for the production of an armouring layer of a flexible pipe and the flexible pipe
AssigneeNKT Flexibles I/S
InventorJonas Gudme
Life of this patent
Estimating the term…
Abstract
The invention relates to a use of a duplex steel for the production of an armouring layer of a flexible pipe comprising at least one unbonded armouring layer and at least one unbonded sealing layer wherein the duplex steel comprises in weight percent 0.01-0.05% by weight of carbon (C) at least 0.15% by weight of nitrogen (N) 20.0-23.0% by weight of chromium (Cr) up to 3.0% by weight of nickel (Ni) up to 1.0% by weight of molybdenum (Mo) 3-6% by weight of manganese (Mn) up to 1.0% by weight of copper (Cu) incidental impurities and balance being iron (Fe).
Claims21
A method of producing a flexible pipe comprising at least one unbonded armouring layer, at least one unbonded sealing layer comprising an internal sealing layer and comprising an inner armouring layer (carcass) inside the internal sealing layer, the method comprising:
- producing the inner armouring layer from a duplex steel wherein the duplex steel comprises in weight percent:
- 0.01-0.05% by weight of carbon (C);
- at least 0.15% by weight of nitrogen (N);
- 20.0-23.0% by weight of chromium (Cr);
- up to 3.0% by weight of nickel (Ni);
- up to 1.0% by weight of molybdenum (Mo);
- 3-6% by weight of manganese (Mn);
- up to 1.0% by weight of copper (Cu);
- incidental impurities;
- and
- balance being iron (Fe).
A flexible pipe comprising:
- at least one unbonded armouring layer, least one unbonded sealing layer comprising an internal sealing layer and comprising an inner armouring layer (carcass) inside the internal sealing layer, wherein the inner armouring layer of the flexible pipe is of a duplex steel having the composition in weight percent:
- 0.01-0.05% by weight of carbon (C);
- at least 0.15% by weight of nitrogen (N);
- 20.0-23.0% by weight of chromium (Cr);
- up to 3.0% by weight of nickel (Ni);
- up to 1.0% by weight of molybdenum (Mo);
- 3-6% by weight of manganese (Mn);
- up to 1.0% by weight of copper (Cu);
- incidental impurities;
- and
- balance being iron (Fe).
A method of transportation of aggressive and corrosive hydrocarbon fluids at deep water, comprising transporting the hydrocarbon fluids from a depth of at least 1000 meters in a flexible pipe comprising:
- at least one unbonded armouring layer and at least one unbonded sealing layer comprising an internal sealing layer and comprising an inner armouring layer (carcass) inside the internal sealing layer, wherein the inner armouring layer of the flexible pipe is of a duplex steel having the composition in weight percent:
- 0.01-0.05% by weight of carbon (C);
- at least 0.15% by weight of nitrogen (N);
- 20.0-23.0% by weight of chromium (Cr);
- up to 3.0% by weight of nickel (Ni);
- up to 1.0% by weight of molybdenum (Mo);
- 3-6% by weight of manganese (Mn);
- up to 1.0% by weight of copper (Cu);
- incidental impurities;
- and
- balance being iron (Fe).
Dependencies are inferred from the claim text.