Core 304LN/4311
EN 1.4311, ASTM TYPE 304LN / UNS S30453

General characteristics

Core 304LN/4311 is a low-carbon, higher nickel and nitrogen alloyed alternative to Core 304/4301 with improved strength and low-temperature toughness. Suitable for applications that require high tensile strength. is an austenitic stainless steel that belongs to the standard CrNi stainless steel family.


The austenitic CrNi standard grades are the most widely used group of stainless steels. Their well-balanced material properties make them suitable for the fabrication of many products. Due to its fully austenitic structure, Core 304LN/4311 is suitable for applications with low magnetic permeability requirements (µ < 1.005).

Typical applications

  • Railroad cars
  • Pressure vessels
  • Chemical plant equipment(mild to medium corrosive environments)
  • Flanges and valves

 

Product forms, available sizes and finishes

Flat

Product typeFinishesThicknessWidth
Cold rolled coil2B, 2BB, 2C, 2D, 2E, 2G, 2H, 2J, 2R0,05-6,003-2050
Cold rolled sheet2B, 2BB, 2D, 2E, 2G, 2H, 2J, 2R0,80-6,00600-2050
Hot rolled coil, pickled1D, 1G, 1U2,00-12,70750-2050
Precision strip2H, 2R0,05-1,503-649
Quarto plate1D5,00-50,00400-3200

Long

Product typeFinishesThicknessWidth
Cast billet127,00-180,00127-180
Cast slab165,00-205,001000-1500
Cold drawn bar hex8,00-25,408-25
Cold drawn bar round6,00-25,406-25
Cold drawn bar square8,00-22,008-22
Rebar coilLP PI6,00-25,006-25
Wire rod (Rod coil) hex9,00-27,009-27
Wire rod (Rod coil) round5,00-27,005-27
Wire rod (Rod coil) square9,00-24,009-24
Chemical composition

The chemical composition may vary slightly between different product standards. The required standard will befully 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.

CMnCrNiMoNOther
Typical 0.0218.59.20.14
ASME II A SA-240 ≤0.030≤2.0018.0-20.08.0-12.00.10-0.16
ASTM A240 ≤0.030≤2.0018.0-20.08.0-12.00.10-0.16
ASTM A666 ≤0.030≤2.0018.0-20.08.0-12.00.10-0.16
EN 10028-7 ≤0.030≤2.0017.0-19.58.5-11.50.12-0.22
EN 10088-2 ≤0.030≤2.017.5-19.58.5-11.50.12-0.22
EN 10088-3 ≤0.030≤2.0017.5-19.58.5-11.50.12-0.22
EN 10088-4 ≤0.030≤2.017.5-19.58.5-11.50.12-0.22
EN 10088-4 -5MEK ≤0.030≤2.017.5-19.58.5-11.50.12-0.22
IS 6911 ≤0.030≤2.0018.0-20.08.0-12.0≤0.700.10-0.16
Mechanical properties

The mechanical properties of the available products in the soft annealed condition at room temperature are given in the table below. Moderate strengths can be reached at elevated temperatures (~550 °C / 1022 °F). Temperatures for excessive scaling are close to 850 °C / 1562 °F. This grade ,along with other austenitic corrosion-resistant steels, exhibits very high ductility and high elongation to fracture. It is not susceptible to brittle fracture in the solution annealed condition.

StandardRp0.2Rp1.0RmElongationImpact strengthRockwellHBHV
 MPaMPaMPa%J
Product type: Cold rolled coil and sheet
Typical (thickness 1 mm)
ASME II A SA-240 ≥ 205 ≥ 515 ≤ 217
ASTM A240 ≥ 205 ≥ 515 ≤ 95HRB ≤ 217
EN 10028-7 ≥ 290 ≥ 320550-750 ≥ 40
EN 10088-2 ≥ 290 ≥ 320550-750 ≥ 40
EN 10088-4 ≥ 290 ≥ 320550-750 ≥ 40
IS 6911 ≥ 205 ≥ 515 ≤ 95HRB ≤ 217
Product type: Hot rolled coil and sheet
Typical (thickness 4 mm)35541066550
ASME II A SA-240 ≥ 205 ≥ 515 ≤ 217
ASTM A240 ≥ 205 ≥ 515 ≤ 217
EN 10028-7 ≥ 290 ≥ 320550-750 ≥ 40
EN 10088-2 ≥ 290 ≥ 320550-750 ≥ 40
EN 10088-4 ≥ 290 ≥ 320550-750 ≥ 40
IS 6911 ≥ 205 ≥ 515 ≤ 95HRB ≤ 217
Product type: Hot rolled quarto plate
Typical (thickness 15 mm)31035064055
ASME II A SA-240 ≥ 205 ≥ 515 ≤ 95HRB ≤ 217
ASTM A240 ≥ 205 ≥ 515 ≤ 95HRB ≤ 217
EN 10028-7 ≥ 270 ≥ 310550-750 ≥ 40
EN 10088-2 ≥ 270 ≥ 310550-750 ≥ 40
EN 10088-4 ≥ 270 ≥ 310550-750 ≥ 40
EN 10088-4 -5MEK ≥ 270 ≥ 310550-750 ≥ 40
IS 6911 ≥ 205 ≥ 515 ≤ 95HRB ≤ 217
Product type: Wire rod
Typical32036064055

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

Core 304LN/4311 has excellent corrosion resistance in solutions of many halogen-free organic and inorganic compounds over a wide temperature and concentration range. It can withstand many organic and sufficiently diluted mineral acids depending on the temperature of the solution. Core 304LN/4311 may suffer from uniform corrosion in strong mineral acids and hot strong alkaline solutions. More detailed information on corrosion properties of Core 304LN/4311 can be found in Outokumpu’s Corrosion Tables published in the Outokumpu Corrosion Handbook and on www.outokumpu.com.


In aqueous solutions containing halogenides, e.g. chlorides or bromides, pitting and crevice corrosion may occur depending on halogenide concentration, temperature, pH-value, concentration of oxidizing compounds, and crevice geometry, if applicable. The presence of corrosion-inhibiting or accelerating compounds like transition metal ions or organic compounds may influence the corrosion behavior of Core 304LN/4311. Due to its high nitrogen content, the resistance of Core 304LN/4311 against pitting and crevice corrosion is slightly increased compared to the basic austenitic CrNi standard grades 4301 and 4307.

 

Core 304LN/4311 is prone to chloride-induced stress corrosion cracking at temperatures over about 50 °C depending on the applied stress and the chloride concentration in the environment. Prior cold deformation of the structure under load increases the risk of stress corrosion cracking.


For more information on corrosion resistance, please refer to the Outokumpu Corrosion Handbook or contact the our corrosion experts.

Pitting corrosion resistanceCrevice corrosion resistance
PRECPTCCT
21<10<0

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

 

DensityModulus of elasticityThermal exp. at 100 °CThermal conductivityThermal capacityElectrical resistanceMagnetizable
kg/dm3GPa10-6/°CW/m°CJ/kg°CµΩm
7.920016.0155000.73No
Fabrication

Cold forming

Core 304LN/4311 can be readily formed and fabricated by the full range of cold forming operations. They can be used in heading, drawing, and bending. Any cold forming operations will increase the strength and hardness of the material, and may leave it slightly magnetic. Work hardening is accentuated by the partial transformation of the austenite phase of the material to hard martensite.

Welding

Core 304LN/4311 has excellent weldability and is suitable for the full range of conventional welding methods (like MMA, MIG, MAG, TIG, SAW, LBW, or RSW), except gas welding. Core 304LN/4311 has about 50% higher thermal expansion and lower heat conductivity compared to carbon steels. This means that larger deformation and higher shrinkage stresses may result from welding.


In thin sections, autogenous welding may be used. To ensure that the weld metal properties (e.g. strength, corrosion resistance) are equivalent to those of the parent metal, matching or slightly over-alloyed fillers should preferably be used. The recommended filler metal is 19 9 L.


Generally, post-weld heat treatment is not required. In special cases where there is high risk of stress corrosion cracking or fatigue, stress relief treatment may be considered.


In order to fully restore the corrosion resistance of the weld seam, the weld discoloration should be removed by pickling and passivation.


Because of the austenitic structure, the welded joints are tough down to low temperatures even in the as-welded condition.

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

Standards & approvals

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

 

StandardDesignation
ASME SA-240M Code Sect. II. Part ATYPE 304LN / UNS S30453
ASTM A240/A240MTYPE 304LN / UNS S30453
ASTM A666TYPE 304LN / UNS S30453
EN 10028-7, PED 2014/68/EU1.4311
EN 10088-21.4311
EN 10088-31.4311
EN 10088-41.4311
IS 6911, AMENDMENT NO. 2ISS 304LN