Core 304L/4306
EN 1.4306, ASTM TYPE 304L

General characteristics

Core 304L/4306 is a higher nickel alternative to Core 304L/4307 with improved formability and deep drawability. Core 304L/4306 is an austenitic stainless steel that belongs to the standard CrNi stainless steel family. Core 304L/4306 has the variant with 10.5 wt.% nickel for improved formability and low carbon content for improved resistance against intergranular corrosion after welding.


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.


Core 304L/4306 is commonly available from many stainless steel stockists in manyproduct forms and dimensions. It can be supplied with a wide range of functional and aesthetic surface finishes.

Typical applications

  • Chemical and pharmaceutical plant equipment (mild to medium corrosive environments)
  • Flanges and valves

 

Product forms, available sizes and finishes

Flat

Product typeFinishesThicknessWidth
Black hot band1U2,40-10,001000-1610
Cold rolled coil2B, 2BB, 2C, 2D, 2E, 2G, 2H, 2J, 2K, 2M, 2R0,05-6,503-2070
Cold rolled sheet2B, 2BB, 2D, 2E, 2G, 2H, 2J, 2K, 2M, 2R0,30-6,5010-2070
Hot rolled coil, pickled1C, 1D, 1E, 1G, 1M, 1U1,86-12,7050-2070
Precision strip2H, 2R0,05-1,503-649
Quarto plate1D5,00-130,00400-3200

Long

Product typeFinishesThicknessWidth
Bloom395,00-405,00295-305
Cast billet127,00-180,00127-180
Cast slab165,00-305,001000-1585
Cold drawn bar hex8,00-25,408-25
Cold drawn bar round6,00-25,406-25
Cold drawn bar square8,00-22,008-22
Forged billet round200,00-230,00200-230
Forged billet square200,00-230,00200-230
Hot rolled / Black bar round75,00-230,0075-230
Peeled / turned bar round70,00-170,0070-170
Rolled billet round75,00-200,0075-200
Rolled billet square75,00-200,0075-200
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 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 0.0218.210.1
EN 10028-7 ≤0.030≤2.0018.0-20.010.0-12.0≤0.10
EN 10088-2 ≤0.030≤2.018.0-20.010.0-12.0≤0.10
EN 10088-3 ≤0.030≤2.0018.0-20.010.0-12.0≤0.10
EN 10088-4 ≤0.030≤2.018.0-20.010.0-12.0≤0.10
Mechanical properties

The mechanical properties of the available products are given in the table below. In addition to these values, several of the chromium-nickel grades are available in the temper rolled condition with higher mechanical strength. Please contact your local Outokumpu sales company for more information.

StandardRp0.2Rp1.0RmElongationImpact strengthRockwellHBHV
 MPaMPaMPa%J
Product type: Cold rolled coil and sheet
Typical (thickness 1 mm)25528558570
EN 10028-7 ≥ 220 ≥ 250520-700 ≥ 45
EN 10088-2 ≥ 220 ≥ 250520-700 ≥ 45
EN 10088-4 ≥ 220 ≥ 250520-700 ≥ 45
Product type: Hot rolled coil and sheet
Typical (thickness 4 mm)25531558055160
EN 10028-7 ≥ 220 ≥ 250520-700 ≥ 45
EN 10088-2 ≥ 220 ≥ 250520-700 ≥ 45
EN 10088-4 ≥ 220 ≥ 250520-700 ≥ 45
Product type: Hot rolled quarto plate
Typical (thickness 15 mm)24027058055
EN 10028-7 ≥ 200 ≥ 240500-700 ≥ 45
EN 10088-2 ≥ 200 ≥ 240500-700 ≥ 45
EN 10088-4 ≥ 200 ≥ 240500-700 ≥ 45
Product type: Wire rod
Typical28032058055

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 304L/4306 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 304L/4306 may suffer from uniform corrosion in mineral acids and hot strong alkaline solutions. Due to its increased nickel content, its uniform corrosion resistance usually matches or supersedes the corrosion resistance of the basic austenitic CrNi standard grades 4301 and 4307. More detailed information on the corrosion properties of Core 304L/4306 can be found in Outokumpu’s Corrosion Tables published in the Outokumpu Corrosion Handbook and on www.outokumpu.com .

Due to its low carbon content, the risk of sensitisation for intergranular corrosion after welding sheets up to 6 mm thick is strongly reduced when compared to other austenitic CrNi standards grades with normal carbon content.


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, or crevice geometry, if applicable. For a short period of time, for instance during cooking of food in stainless steel dishes, Core 304L/4306 can tolerate even relatively high chloride concentrations. The presence of corrosion-inhibiting or accelerating compounds like e.g. transition metal ions or organic compounds may influence the corrosion behaviour of grade Core 304L/4306.

Pitting corrosion resistanceCrevice corrosion resistance
PRECPTCCT
18<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

Physical properties. Values 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 304L/4306 can be readily formed and fabricated using a full range of cold forming operations. It 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 aaccentuated by the partial transformation of the austenite phase of the material to hard martensite.

Hot forming

Hot forming can be carried out in the 850 °C–1150 °C range. For maximum corrosion resistance, forgings should be annealed at 1050 °C and rapidly cooled in air or water after hot forming operations.

Welding

Core 304L/4306 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 304L/4306 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 overalloyed fillers should preferably be used. The recommended filler metal is 19 9 L.

Post-weld heat treatment is generally 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
EN 10028-7, PED 2014/68/EU1.4306
EN 10088-21.4306
EN 10088-31.4306
EN 10088-41.4306