Duplex and other high strength stainless steel

Forta

The Forta range contains the following: Duplex, H-Series and temper rolled austenitic and ferritic products. These high strength stainless steels enable thinner structures and weight reduction.

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Outokumpu Forta grades

Forta DX 2205

Forta DX 2205 is the most popular duplex product on the market. It offers very good resistance to uniform and localized corrosion and stress corrosion cracking in combination with high mechanical strength.

Typical applications
  • Tanks in chemical tankers
  • Pulp and paper industry applications such as digesters and process tanks
  • Oil and gas industry applications such as flanges, valves, tubes, and pipes
  • Structural components in bridges
Product forms
Chemical composition

Forta LDX 2101®

Forta LDX 2101 is a lean-alloyed duplex product with good resistance to localized and uniform corrosion, as well as stress corrosion cracking, making it a good substitute for coated carbon steel. It also offers high mechanical strength and good machinability.

Typical applications
  • Storage tanks
  • Household heaters
  • Structural components for floodgates and bridges or rebar for concrete structures
  • Pulp and paper industry applications
  • Flanges and valves
Product forms
Chemical composition

Forta DX 2304

Duplex grade with good resistance to localized corrosion and stress corrosion cracking in combination with high mechanical strength. Used in e.g. offshore topside applications since more than 20 years.

The grade is also available as Forta EDX 2304 with enhanced corrosion resistance and strength, but still within the same EN/ASTM standards as Forta DX 2304. The EDX version has a NORSOK approval from Aker Engineering & Technolgy ASaccording to NORSOKM standard M-650 Edition 4, September 2011 "Qualification of manufacturers of special materials".

Typical applications
  • Desalination plants
  • Firewalls and blast walls on offshore platforms
  • Bridges
  • Components for structural design
  • Storage tanks
  • Pressure vessels
  • Heat exchangers
  • Water heaters
  • Rotors, impellers and shafts
Product forms
Chemical composition

Forta EDX 2304

Typical applications
Product forms
Chemical composition

Forta LDX 2404®

Austenitic-ferritic stainless steel also referred to as duplex stainless steels, combine many of the beneficial properties of ferritic and austenitic steels. Due to the high content of chromium and nitrogen, and often also molybdenum, these steels offer good resistance to localised and uniform corrosion. The duplex microstructure contributes to the high strength and high resistance to stress corrosion cracking. Duplex steels have good weldability. All duplex grades have the maximum service temperature restricted to 250 or 325°C according to EN10028-7 or ASME II-D 2007 respectively. Outokumpu produces a range of duplex grades, LDX 2101®; 2304; LDX 2404®; 2205; 4501 and 2507.

LDX 2404®is a molybdenum-containing duplex stainless steel with high contents of chromium and nitrogen. The grade combines a higher mechanical strength than for other common duplex grades with a generally high corrosion resistance.These characteristics make

LDX 2404® well suited for optimal designs with respect to strength, reduced maintenance, durability and long-term cost efficiency.

Typical applications
  • Pulp and paper industry
  • Desalination plants
  • Cargo tanks and pipe systems in chemical tankers
  • Firewalls and blast walls on offshore platforms
  • Components for structural design
  • Boilers and water heaters
  • Storage tanks
  • Pressure vessels
  • Water heaters
  • Heat exchangers
  • Rotors, impellers and shafts
  • Bridges
  • Flue-gas cleaning
Product forms
Chemical composition

Forta SDX 100

Austenitic-ferritic stainless steel also referred to as duplex stainless steels, combine many of the beneficial properties of ferritic and austenitic steels. Due to the high content of chromium and nitrogen, and often also molybdenum, these steels offer good resistance to localised and uniform corrosion. The duplex microstructure contributes to the high strength and high resistance to stress corrosion racking. Duplex steels have good weldability. All duplex grades have the maximum service temperature restricted to 250 or 325°C according to EN10028-7 or ASME II-D 2007 respectively. Outokumpu produces a range of duplex grades, LDX 2101®, 2304, LDX 2404®, 2205, 4501 and 2507. The properties of 4501 is in general terms very similar to those of 2507. Grade 4501 is delivered if specified.

Typical applications

• Pulp and paper industry
• Desalination plants
• Flue-gas cleaning
• Cargo tanks and pipe systems in chemical tankers
• Seawater systems
• Firewalls and blast walls on offshore platforms
• Components for structural design
• Storage tanks
• Pressure vessels
• Heat exchangers
• Water heaters
• Rotors, impellers and shafts
Product forms
Chemical composition

Forta SDX 2507

Forta SDX 2507 is a super duplex product with higher corrosion resistance and mechanical strength than Forta DX 2205. Often used in extremely corrosive environments such as desalination, chemical, or offshore subsea applications.

Typical applications
  • Desalination plants
  • Industrial piping
  • Scrubbers
  • Tubes for oil and gas applications
  • Deep-sea pipelines
  • Flanges and valves
Product forms
Chemical composition

Forta H400

Forta H400 has higher strength than standard Core 304/4301 and a lower nickel content, making it a cost-effective and lightweight austenitic product for the automotive industry. It has been used in automotive applications for over 10 years.

Forta H400 is an austenitic stainless steel, which belongs to the austenitic low-nickel CrMn stainless steel family, in which manganese replaces part of the nickel that is normally alloyed to CrNi standard grades. This variant has low carbon content. Due to its high nitrogen content, Forta H400 has increased mechanical strength. Forta H400 is optimized for strong work hardening on mechanical deformation.

The corrosion resistance of the austenitic CrMn grades is usually slightly below that of the austenitic CrNi standard grades. Forta H400 is used in applications where a combination of high mechanical strength and good formability, as well as corrosion resistance, is needed. Due to its strong tendency to work hardening, Forta H400 can absorb a high amount of energy during deformation. It can be delivered in the temper rolled condition with different strength levels.

Typical applications
  • Cross members
  • Strut domes
  • Bumpers
Product forms
Chemical composition

Forta 430/4016

Forta 430/4016 is a classic 16% chromium ferritic stainless steel for mildly corrosive environments. Not recommended for welding due to its decreased intergranular corrosion resistance

Typical applications
  • Tanks
  • Cutlery
  • Household appliances
Product forms
Chemical composition

Forta 301LN/4318

Forta 301LN/4318 is a low-carbon, nitrogen-alloyed alternative to Forta 301/4310 with elevated strength, making it particularly suitable for lightweight construction applications.

Typical applications
  • Vehicle chassis
Product forms
Chemical composition

Forta 304/4301

Forta 304/4301 is a classic 18% chromium, 8% nickel austenitic stainless steel. Forta 304/4301 is an all-purpose product with good resistance to atmospheric corrosion and to many organic and inorganic chemicals.

Typical applications
  • Vehicle chassis
  • Containers
  • Constructions
Product forms
Chemical composition

Forta 304L/4307

Forta 304L/4307 is a low-carbon alternative to Core 304/4301. Forta 304L/4307 is an all- purpose product with good resistance to atmospheric and intergranular corrosion.

Typical applications
  • Steel constructions
  • Containers
  • Vehicle chassis
Product forms
Chemical composition

Forta 316/4401

A normal-carbon, molybdenum-alloyed stainless steel that is widely used for various applications with higher than average corrosion resistance requirements. Forta 316/4401 is strengthened with temper rolling for applications that require specific strength.

Typical applications
  • Chemical tanks
Product forms
Chemical composition

Forta 316L/4404

A low-carbon, molybdenum-alloyed alternative to Supra 316/4401 that is widely used for various applications with higher than average corrosion resistance requirements. Forta 316L/4404 is strengthened with temper rolling for applications that require specific strength as well as improved weldability and intergranular corrosion resistance.

Typical applications
  • Chemical tanks and tubing
  • Pulp and paper process equipment
Product forms
Chemical composition

Forta 316plus®

Typical applications
Product forms
Chemical composition

Forta 316Ti/4571

Forta 316Ti/4571 is a titanium-stabilized, molybdenum-alloyed austenitic steel for highly corrosive environments, including applications in elevated temperatures.

Typical applications
  • Chimney constructions
  • Flue gas applications
Product forms
Chemical composition

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DUplex and other High strength Stainless Steels

Forta

The Forta range contains duplex, H-Series and temper rolled austenitic and ferritic stainless steels that enable thinner structures and weight reduction (measured in Rp0.2 > 350 MPa. PRE 16 - 43). 

Duplex (austenitic-ferritic) stainless steel combines many of the best properties of austenitic and ferritic stainless steels: high strength, good corrosion resistance and enhanced resistance to stress- corrosion cracking (Rp0.2 > 400 MPa. PRE 26 - 43).

Forta DX 2205 (EN 1.4462) is the most well-known duplex product, offering very good resistance to uniform and localized corrosion and stress- corrosion cracking in combination with high mechanical strength. Super duplex Forta SDX 2507 (EN 1.4410), with higher corrosion resistance and mechanical strength than Forta DX 2205, is often used in extremely corrosive environments such as desalination, chemical or offshore subsea applications.

H-series are manganese containing fully austenitic stainless steels with high strength and high ductility (Rp0.2 > 400 MPa. PRE  21). Forta H400 (EN 1.4376) with lower nickel content has higher strength than standard austenitic stainless steels 304/304L and is a cost-effective solution for automotive lightweight applications.

Forta H500 (EN 1.4678) has a fully austenitic and non-magnetizable microstructure with significant strain-hardening due to twinning. With a yield strength higher than 500 MPa, it is a perfect lightweight alternative for safety- relevant components in the automotive and transportation industry. 

Temper-rolled stainless steels have high strength and high hardness (Rp0.2 > 350 MPa. PRE 16 - 25). Temper rolling means a controlled additional cold rolling process that is applied to standard austenitic and ferritic stainless steels and it increases the strength and surface hardness of the steels. The strength classification includes yield strength classes from CP350 up to CP1100 MPa and tensile strength classes from C700 up to C1900 MPa.

Temper-rolled austenitic stainless steel Forta 301/4310 (EN 1.4310) can reach the highest strength class. Forta H800 (EN 1.4678) and Forta H1000 (EN 1.4678) are the temper-rolled condition of Forta H500 and still non-magnetic. They offer higher resistance for crash-relevant parts and a cost-effective and price-stable solution in the automotive industry. 

Standards and approvals

EN ISO 18286     Hot-rolled stainless steel plates – Tolerances on dimensions and shape  
EN 10051 Hot-rolled steel strip.
EN 10088-1 Stainless steels – list of stainless steels 
ISO 15510 Stainless steels – chemical composition 
EN ISO 9445 Cold-rolled stainless narrow strip, wide strip, plate/sheet and cut lengths. 
ASTM A 480 General requirements for flat-rolled stainless and heat resisting steel 
ASTM A 959 Harmonized standard grade compositions for wrought stainless steels 
ASME IID Materials – Physical properties tables 


 EN 10028-7   Flat products for pressure purposes – Stainless steels
 EN 10088-2  Stainless steels – sheet/plate and strip for general purposes
 EN 10088-3  Stainless steels – semi-finished products, bars, rods sections for general purposes
 EN 10088-4  Technical delivery conditions for sheet/plate and strip
 EN 10088-5  Technical delivery conditions for bars, rods wire, sections and bright products of corrosion resisting steels for construction purposes
 EN 10095  Heat resisting steels and nickel alloys
 EN 10151  Stainless steel strip for springs
 EN 10302  Creep resisting steels, nickel and cobalt alloys
 ASTM A 167  Stainless and heat-resisting Cr-Ni steel plate, sheet, and strip
 ASTM A 176  Stainless and heat-resisting Cr steel plate, sheet, and strip
 ASTM A 240  Cr and Cr-Ni stainless steel plate, sheet and strip for pressure vessels
 ASTM A276  Stainless steel and heat resisting steel bars and shapes
 ASTM A479/479M  Stainless steel bars for boilers/pressure vessels
 ASTM A493  Stainless steel and heat-resisting steel rod and wire for cold heading and forging
 ASTM A555  General requirements for stainless and heat resistant steel wire and wire rod
 ASTM A 666  Austenitic stainless steel sheet, strip, plate, bar for structural and architectural applications
 ASME IIA  Materials. Part A – Ferrous Material Specifications
      

Forta DX 2304, Forta DX 2205, and Forta SDX 2507 are listed in EN 10028-7:2007.

European material approval EAM 0045-01:2012/01 for Forta LDX 2101 is available for cold rolled 0.5-6.4 mm and hot rolled 3.0–10.0 mm.

In ASME II-D 2013, Forta DX 2205 (S31803 and S32205). Forta EDX 2304 (S32304), Forta SDX 100 (S32760) and Forta SDX 2507 (S32750) are listed for general use in the temperature range -30 – 316 °C. Data for Forta LDX 2101 and Forta LDX 2404 can be found in ASME code case 2418-1 and 2780 respectively.


Outokumpu meets the most common certifications and approvals around the world, including:

  • AD 2000 Merkblatt
  • Approval of Material Manufacturers
  • Factory Production Control Certificate
  • ISO 9001
  • ISO 14001
  • ISO 50001
  • ISO/TS 16949
  • NORSOK
  • OHSAS 18001
  • Pressure Equipment Directive (PED)

Outokumpu Forta range downloads

Outokumpu Forta duplex datasheet
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Outokumpu Forta Temper rolled stainless steels
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Outokumpu Product Ranges chart
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Machining guidelines for Forta DX2205
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Machining guidelines for Forta DX2304
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Machining guidelines for Forta LDX2404®
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Machining guidelines for Forta SDX 2507
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Machining guidelines for Forta LDX 2101
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Machining guidelines for standard austenitic stainless steel grades
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