Ultra 725LN
EN 1.4466, ASTM UNS S31050

General characteristics

High Ni and Mo austenitic grade with similar corrosion resistance to 904L. Typically used in Urea applications. Available as plate only.

Typical applications

  • Urea applications
  • Pulp & Paper industry
  • Flue gas cleaning
  • Chemical industry
  • Pharmaceutical industry

 

Product forms, available sizes and finishes

Flat

Product typeFinishesThicknessWidth
Quarto plate1D5,00-50,00400-3200
Chemical composition

The chemical composition may vary slightly between different product standards. The required standard will be fully met as specified on the order.

The chemical composition is given as % by weight.

CMnCrNiMoNOther
Typical 0.0125.022.32.10.12
ASME II A SA-240 ≤0.020≤2.024.0-26.020.5-23.51.6-2.60.09-0.15
ASTM A240 ≤0.020≤2.0024.0-26.020.5-23.51.60-2.600.09-0.15
EN 10028-7 ≤0.020≤2.0024.00-26.0021.00-23.002.00-2.500.10-0.16
EN 10088-2 ≤0.020≤2.024.0-26.021.0-23.02.0-2.50.10-0.16
EN 10088-4 ≤0.020≤2.024.0-26.021.0-23.02.0-2.50.10-0.16
IS 6911 ≤0.20≤2.024.0-26.020.5-23.51.60-2.600.09-0.15
Mechanical properties

The mechanical properties of the available products are given in the table below.

 

StandardRp0.2Rp1.0RmElongationImpact strengthRockwellHBHV
 MPaMPaMPa%J
Product type: Cold rolled coil and sheet
ASTM A240 ≥ 255 ≥ 540 ≤ 95HRB ≤ 217
IS 6911 ≥ 255 ≥ 540 ≤ 95HRB ≤ 217
Product type: Hot rolled coil and sheet
ASTM A240 ≥ 255 ≥ 540 ≤ 217
IS 6911 ≥ 255 ≥ 540 ≤ 95HRB ≤ 217
Product type: Hot rolled quarto plate
Typical (thickness 15 mm)28030063055
ASME II A SA-240 ≥ 255 ≥ 540 ≤ 95HRB ≤ 217
ASTM A240 ≥ 255 ≥ 540 ≤ 95HRB ≤ 217
EN 10028-7 ≥ 250 ≥ 290540-740 ≥ 40
EN 10088-2 ≥ 250540-740 ≥ 40
EN 10088-4 ≥ 250 ≥ 290540-740 ≥ 40
IS 6911 ≥ 255 ≥ 540 ≤ 95HRB ≤ 217

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

For more information, see Outokumpu Corrosion Handbook.

Pitting corrosion resistanceCrevice corrosion resistance
PRECPTCCT
34

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

Data according to EN 10088, EN 10095 or typical values.

 

DensityModulus of elasticityThermal exp. at 100 °CThermal conductivityThermal capacityElectrical resistanceMagnetizable
kg/dm3GPa10-6/°CW/m°CJ/kg°CµΩm
8,019515,7145000,80No
Fabrication

Welding

Outokumpu 725LN can be readily welded by a full range of conventional welding methods such as:
Shielded metal arc welding (SMAW)
Gas tungsten arc welding, TIG (GTAW)
Gas metal arc welding, MIG /MAG(GMAW)
Flux-cored arc welding (FCAW)
Plasma arc welding (PAW)
Submerged arc welding (SAW)

The steel is fully austenitic. For this reason, the sensitivity to hot cracking should be taken into account. MAG welding may  require modern pulse equipment and the use of special shielding gases containing Ar, He and O2/CO2.

 

Standards & approvals

The most commonly used international product standards are given in the table below.

 

StandardDesignation
ASME SA-240M Code Sect. II. Part AUNS S31050
ASTM A240/A240MUNS S31050
EN 10028-7, PED 2014/68/EU1.4466
EN 10088-21.4466
EN 10088-41.4466
IS 6911, AMENDMENT NO. 2ISS 310MoLN