Offshore Steels

Predominantly, offshore structures are built specifically for drilling oil and gas deposits deep under the sea bed. Whilst applications will vary, all will have exposure to the effects of salt water corrosion, powerful sea currents often dictated by the tides and strong winds. Our search for natural fuel resources has stretched into even more inaccessible areas such as the Arctic which has also resulted in rigs drilling at much greater depths and hence lower temperatures.

Structures in harsh working environments like these require a specific range of steels to promote greater safety, longer working life and reduce the risk of failure which in certain cases could prove disastrous.

Offshore Steel Characteristics:

  • High yield strength
  • Excellent weldability
  • Good internal soundness
  • Good resistance to brittle fracture (longitudinal and transverse)
  • Low phosphorus and sulphur contents
  • High resistance to lamellar tearing

S355G7+M/+N

S355G7+M/+N

S355G7 is a structural grade steel supplied to the offshore industry. The material can be delivered as normalised (N) or thermo-mechanically rolled (M). Supplied in accordance with EN10225:2001, the steel offers good tensile and yield strength.

As an offshore steel grade, S355G7 is used in a variety of applications including the building of offshore platforms. Masteel UK Limited can supply the steel from stock or directly from the mill to customer destinations on a global footing. Please refer to the technical information for S355G7.

 

Chemical Composition of S355G7

 %
C0.14
Si0.15/0.55
Mn1.00/1.65
P0.02
S0.01
Cr0.25
Mo0.08
Ni0.5
Al0.015/0.055
Cu0.3
N0.01
Nb0.04
Ti0.025
V0.06
Nb+V0.06

Mechanical Properties of S355G7

GradeMechanical Properties (min) unless sated     Tensile Strength Rm MPa  
Tensile StrengthNominal Thickness (mm)
Thickness (mm)Elongation A
< 100>100<16>16 <25>25 <40>40 <63>63 <100>100 <150%
S355G7+M470/630-355355345335325-22
S355G7+N470/630460/62035535534533532532022

S355G8+M/+N

S355G8+M/+N

S355G8 comes under the standard EN10225:2001 which the technical delivery condition for weldable steels for fixed offshore structures.

S355G8 can either be normalised (N) or thermo-mechnically rolled (M) and is a structural grade offering good tensile and yield strength. The steel is used throughout the offshore oil and gas industry in the construction of structures and platforms.

Please refer to the technical information below for S355G8+M and S355G8+N.

Chemical Composition of S355G8+M/+N

 %
C0.14
Si0.15/0.55
Mn1.00/1.65
P0.02
S0.007
Cr0.25
Mo0.08
Ni0.5
Al0.015/0.055
Cu0.3
N0.01
Nb0.04
Ti0.025
V0.06
Nb+V0.06

Mechanical Properties of S355G8+M/+N

GradeMechanical Properties (min) unless sated     Tensile Strength Rm MPa  
Tensile StrengthNominal Thickness (mm)
Thickness (mm)Elongation A
< 100>100<16>16 <25>25 <40>40 <63>63 <100>100 <150%
S355G8+M470/630-355355345335325-22
S355G8+N470/630460/62035535534533532532022

S355G9+N/+M

S355G9+M/+N

S355G9 – an offshore quality structural steel used in the offshore industry.

Supplied under the EN10225:2001 standard, the material shows good tensile and yield strength and has good weldability. The steel is used throughout the offshore industry in the building of offshore steel structures & platforms which are subjected to some of the harshest weather conditions.

Please refer to the chemical composition and mechanical properties below for S355G9+M and S355G9+N.

Mechanical Properties of S355G9+M/+N

DescriptionGrade 60
Tensile strength (ksi)60-80
Tensile strength (MPa)415-550
Yield strength (ksi)32
Yield strength (MPa)220
Elongation in 200mm (min)(%)21
Elongation in 50mm (min) (%)25
Thickness (max)(mm)205

(Minimum values unless stated otherwise)

(Please note: the technical information above is for guidance only – for exact specifications please check with our Sales Team)

Chemical Composition of S355G9+M/+N

 %
C0.14
Si0.15/0.55
Mn1.65
P0.02
S0.01
Cr0.20
Mo0.08
Ni0.7
Al0.015/0.055
Cu0.3
N0.01
Nb0.03
Ti0.025
V0.06
Nb+V0.06

S355G10+M/+N

S355G10+M/+N

Masteel supplies S355G10 offshore grade steel in both normalised (N) and thermo-mechanically rolled (M) condition.

Produced to the euro norm standard EN10225:2001,the specification governing weldable structural steels for offshore structures, S355G10 has good tensile and yield strength.

The steel can be supplied as heavy plates or as pre-fabricated sections. Please refer to our technical information below.

Chemical Composition of S355G10+M/+N

 %
C0.12
Si0.15/0.55
Mn1.65
P0.015
S0.005
Cr0.20
Mo0.08
Ni0.7
Al0.015/0.055
Cu0.3
N0.01
Nb0.03
Ti0.025
V0.06
Nb+V0.06

Mechanical Properties of S355G10+M/+N

GradeMechanical Properties (min) unless sated     Tensile Strength Rm MPa  
Tensile StrengthNominal Thickness (mm)
Thickness (mm)Elongation A
< 100>100<16>16 <25>25 <40>40 <63>63 <100>100 <150%
S355G10+M470/630-355355345335325-22
S355G10+N470/630460/62035535534533532532022

S420G1+Q/+M

S420G1+Q/+M

S420G1 is an offshore structural grade steel. The material can be delivered as quenched (Q) or thermo-mechanically rolled (M). We supply the material in accordance with EN10225:2001.

S420G1 has good yield and tensile strength and is used in the construction of offshore platforms and oil rigs. Masteel UK Limited specialise in the supply of offshore steel products to the global oil and gas industry.

Please refer to the technical information for S420G1+M and S450G1+Q below.

Mechanical Properties of S420G1+Q/+M

GradeMechanical Properties (min) unless sated     Tensile Strength Rm MPa 
Tensile StrengthNominal Thickness (mm)
Thickness (mm)Elongation A
< 40>40 <100<16>16 <40>40 <63>63 <80>80 <100%
S420G1+M500/660480/64042040039038038019
S420G1+Q500/660480/64042040039038038019

Chemical Composition of S420G1+Q/+M

 %
C0.14
Si0.15/0.55
Mn1.65
P0.02
S0.01
Cr0.25
Mo0.25
Ni0.7
Al0.015/0.055
Cu0.3
N0.01
Nb0.04
Ti0.025
V0.08
Nb+V0.09

S420G2+Q/+M

S420G2+Q/+M

Supplied to the offshore industry as a structural steel grade, S420G2 is a high tensile and high yield steel used in the construction of oil rigs and offshore service platforms.

Complying with EN10025:2001, the material is supplied as either S420G2+M (thermo–mechanically rolled) or S420G2+Q (Quenched). We supply offshore marine grades such as S420G2 from stock or directly shipped from the mill to clients around the world.

Please refer to the technical information for both grades below.

Mechanical Properties of S420G2+M/+Q

GradeMechanical Properties (min) unless sated     Tensile Strength Rm MPa 
Tensile StrengthNominal Thickness (mm)
Thickness (mm)Elongation A
< 40>40 <100<16>16 <40>40 <63>63 <80>80 <100%
S420G2+M500/660480/64042040039038038019
S420G2+Q500/660480/64042040039038038019

Chemical Composition of S420G2+Q/+M

 %
C0.14
Si0.15/0.55
Mn1.65
P0.02
S0.07
Cr0.25
Mo0.25
Ni0.7
Al0.015/0.055
Cu0.3
N0.01
Nb0.04
Ti0.025
V0.08
Nb+V0.09

S460G1+Q/+M

S460G1+Q/+M

Offshore steel grade S460G1 is supplied under the specification EN10225:2001.

The steel which is available in either quenched (Q) or thermo-mechanically rolled (M) condition, is used in the construction of fixed offshore structures including oil rigs and service platforms.

With higher yield and tensile strength, the material has good weldability characteristics and can be supplied as heavy carbon steel plates or fabricated sections. Masteel UK Limited supply S460G1 to the global oil and gas industry.

Mechanical Properties of S460G1+M/+Q

For all S460 Grades< 16>16 <25>25 <40>40 <63>63 <80>80 <100
Yield Strength N/mm2460440420415405400
Tensile Strength N/mm2540/700530/690520/680515/675505/665500/660
Elongation A (%)17
Impact Energy60J at -40

Chemical Composition of S460G1+M/+Q

 %
C0.14
Si0.15/0.55
Mn1.65
P0.02
S0.01
Cr0.25
Mo0.25
Ni0.7
Al0.015/0.055
Cu0.3
N0.01
Nb0.04
Ti0.025
V0.08
Nb+V0.09

S460G2+Q/+M

S460G2+Q/+M

Masteel offers S460G2 – a structural grade steel for specific use in the offshore industry as supplied under specification EN10025:2001.

With a minimum yield strength of 460 N/mm², S460G2 is engineered specifically for use in the building of offshore structures such as service platforms and oil rigs. The material can be supplied as S460G2+Q (Quenched) or S460G2+M (thermo-mechanically rolled).

Masteel supplies S460G2 to the oil and gas industry on a global basis.

Mechanical Properties of S460G2+Q/+M

For all S460 Grades< 16>16 <25>25 <40>40 <63>63 <80>80 <100
Yield Strength N/mm2460440420415405400
Tensile Strength N/mm2540/700530/690520/680515/675505/665500/660
Elongation A (%)17
Impact Energy60J at -40

Chemical Composition of S460G2+Q/+M

 %
C0.14
Si0.15/0.55
Mn1.65
P0.02
S0.07
Cr0.25
Mo0.25
Ni0.7
Al0.015/0.055
Cu0.3
N0.01
Nb0.04
Ti0.025
V0.08
Nb+V0.09

API 2H

API 2H Grade 50

API 2H Grade 50 is an offshore steel grade which is regulated by the American Bureau of Shipbuilding (ABS).

Whilst originally designed as a structural steel for use in the welded construction of offshore platforms, the material is also used in other applications due to the tight controls placed on the chemical composition of the steel at the mill stage.

The primary use of API 2H Grade 50 is in critical areas of the construction where good impact and fatigue resistance is required. API 2H Grade 50 can be found in stiffened plate construction, tubular joints, and other intersections where parts of the plates are subjected to through-thickness tension.

The steel is also used as a piling material for bridge construction due to its fracture, vibration and torque resistance. API 2H Grade 50 is therefore not only in effective material for floating and rigid offshore platform construction, it also has other uses as a high yield and highly specified structural grade material.

Key Features:
  • Structural offshore grade for critical applications
  • High yield with excellent fracture and impact resistance
  • Resistance to lamellar tearing
  • Though classed as a marine grade, can be used in a variety of applications due to stringent spec

API 2W

API 2W Grade 50

 

Thermo-mechanically rolled for extra strength and toughness, API 2W Grade 50 is a structural offshore steel grade which is regulated by the American Bureau of Shipbuilding (ABS).

The material is used in the production of floating and rigid offshore oil and gas platforms and is used commonly in intersections of the structure due to the materials superior strength combined with good impact and fatigue resistance.

API 2W Grade 50 provides good toughness around the heat affected zone (HAZ) so is an ideal material for use in the welded joints of the construction.

The stringent chemical composition of the material makes API 2W Grade 50 an excellent structural steel where resistance to fracture, vibration or torque is required (as found in bridge construction).

The steel has arguably better welding characteristics than API 2H Grade 50 due to the materials lower carbon content.

Key Features:
  • Structural offshore grade for critical applications
  • Lower carbon content for improved weldability
  • Thermo-mechanically rolled for extra strength and toughness
  • Good impact resistance in heat affected zone (HAZ)
  • Resistance to lamellar tearing

Masteel UK Limited supplies API 2W Grade 50 plates to clients on an international basis.

Whatever your steel requirement or specification, Masteel has the knowledge and resources to provide you with a first class steel supply option.