Forta LDX 2101
EN 1.4162, ASTM UNS S32101

General characteristics

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, available sizes and finishes


Product typeFinishesThicknessWidth
Cold rolled coil and sheet2B, 2E0,80-6,35≤ 2000
Hot rolled coil and plateHot rolled white3,00-10,00≤ 2000
Quarto plateHot rolled white5,00-100,00≤ 3200
Chemical composition

The typical chemical composition for this grade is given in the table below, together with composition limits given for this grade according to different standards. The required standard will be fully met as specified on the order.


The typical chemical composition for this grade is given in the table below, together with composition limits given for the product according to different standards. The required standard will be fully met as specified on the order.

The chemical composition is given as % by mass.

TypicalForta LDX 21010.
ASTM A240/A240MUNS S32101<0.044.0-6.021.0-22.01.35-1.700.10-0.800.20-0.25Si:<1 P:<0.040 S:<0.030 Cu:0.10-0.80
EN 10088-21.4162<0.044.0-6.021.0-22.01.35-1.700.10-0.800.20-0.25Si:<1 P:<0.035 S:<0.005 Cu:0.10-0.80
Mechanical properties

Forta LDX 2101 is part of the Outokumpu Forta range of stainless steels with high mechanical strength. If the high strength  can be utilized, downgauging can be done in many applications, leading to cost-efficient solutions. The allowable design values may vary between product forms. The appropriate values are given in the relevant specifications.

Mechanical properties at room temperature are shown in the table below.

StandardGradeRp0.2Rp1.0RmImpact strengthRockwellHBHV
Product type: Cold rolled coil and sheet
Typical (thickness 1 mm)Forta LDX 210161066081099HRB
Product type: Hot rolled coil and sheet
Typical (thickness 4 mm)Forta LDX 2101560630755235
Product type: Hot rolled quarto plate
Typical (thickness 15 mm)Forta LDX 2101500700225

1)Elongation according to EN standard:
A80 for thickness below 3 mm.
A for thickness = 3 mm.
Elongation according to ASTM standard A2” or A50.

Corrosion resistance

Uniform corrosion

Forta LDX 2101 has good resistance to uniform corrosion due to the high chromium content. For guidance on material selection in a large number of environments capable of causing uniform corrosion, consult the tables and isocorrosion diagrams in the Corrosion tables -webpage.


Pitting and crevice corrosion

Chloride ions in a neutral or acidic environment facilitate local breakdown of the passive layer. As a result, pitting and crevice corrosion can propagate at a high rate, causing corrosion failure in a short time. Since the attack is small and may be covered by corrosion products or hidden in a crevice, it often remains undiscovered until perforation or leakage occurs. Resistance to pitting corrosion is determined mainly by the content of chromium, molybdenum, and nitrogen content. Forta LDX 2101 has good resistance to pitting and crevice corrosion due to the chromium and nitrogen content.

Stress corrosion cracking

Forta LDX 2101 has good resistance to chloride-induced stress corrosion cracking. This form of corrosion is a combination of stresses in the material and a corrosive environment, mainly at elevated temperatures. Stresses in the material can be a result of fabrication, like forming or welding.

Pitting corrosion resistanceCrevice corrosion resistance

PRE Pitting Resistant Equivalent calculated using the formula: PRE = %Cr + 3.3 x %Mo + 16 x %N
CPT Corrosion Pitting Temperature as measured in the Avesta Cell (ASTM G 150), in a 1M NaCl solution (35,000 ppm or mg/l chloride ions).
CCT Critical Crevice Corrosion Temperature is the critical crevice corrosion temperature which is obtained by laboratory tests according to ASTM G 48 Method F



Physical properties

The physical properties at room temperature are shown in the table below. Data according to EN 10088 or EN 10095.


DensityModulus of elasticityThermal exp. at 100 °CThermal conductivityThermal capacityElectrical resistanceMagnetizable


Forta LDX 2101 is suitable for all forming processes applicable to stainless steel. The high yield strength compared to austenitic and ferritic stainless steel can impose some differences in forming behavior depending on the chosen forming technique, such as an increased tendency to springback. This point is particularly relevant to the forming of any high-strength steel. Higher forces may be needed in forming operations, but the possibilities of downgauging offer a viable solution.


Duplex steels are generally more demanding to machine than conventional austenitic stainless steels, but Forta LDX 2101 is an exception as it has excellent machineability. Machining guidelines are available for Forta LDX 2101 here:
Machining guidelines Forta LDX 2101


Forta LDX 2101 has good weldability and can be welded using most of the common methods used for stainless steel:

  • Shielded metal arc welding (SMAW)
  • Gas tungsten arc welding TIG(GTAW)
  • Gas metal arc welding MIG (GMAW)
  • Flux-cored arc welding (FCW)
  • Plasma arc welding (PAW)
  • Submerged arc welding (SAW)
  • Laser welding
  • Resistance welding
  • High frequence welding

The following general instructions should be followed:

  • The material should be welded without preheating.
  • The material should be allowed to cool between passes, preferably to below 150 °C;
  • To obtain good weld metal properties in the as-welded condition, filler material should be used. Forta LDX 2101 can also obtain reasonably good properties without filler.
  • The recommended arc energy should be kept within certain limits to achieve a good balance between ferrite and austenite in the weld. The heat input should be adapted to the steel grade and be adjusted in proportion to the thickness of the material being welded.
  • Post-weld annealing after welding with filler is not necessary.
  • To ensure optimum pitting resistance when using GTAW and PAW methods, the addition of nitrogen to the shielding/purging gas is recommended.
  • Removal of weld oxides after welding is important to restore the corrosion properties of the weld and HAZ.

More detailed information concerning welding procedures can be obtained from the Outokumpu Welding Handbook, available from our sales offices.

Standards & approvals

Outokumpu produces and certifies materials to most international and national standards. Work is ongoing to have the different grades approved for relevant standards.


ASTM A240/A240MUNS S32101
EN 10088-21.4162

Note: For pressure purposes Forta LDX 2101 has a Particular Material Appraisal from TÜV and Inspecta. Maximum service temperature is 250 ºC.