AISI 318LN | 1.4462 | BS 318S13 | X2CrNiMoN22-5-3 | Duplex steel
Material information according to DIN EN 10088-3
The material AISI 318LN is an austenitic-ferritic duplex steel, also known under the designations 1.4462, BS 318S13 and X2CrNiMoN22-5-3. It is characterised by good mechanical properties and good corrosion resistance (PREN value 30.9 to 38.0). AISI 318LN stainless steel is resistant to intergranular corrosion and stress corrosion cracking and can also be used in contact with seawater. The material is polishable and magnetic (ferromagnetic). It can be used in a temperature range of -100°C to 250°C. In the solution-annealed condition (+AT at room temperature), the material has a tensile strength of 650 to 880 N/mm² and a hardness of ≤ 270. The density is 7.80 kg/dm³ (at 20°C). The duplex steel AISI 318LN/1.4462 can be processed using many welding methods. It is suitable for cold forming (cold massive forming), but only to a limited extent for cold heading. The material is moderately forgeable and difficult to machine. This stainless steel is frequently used in shipbuilding, for offshore plants or in the petrochemical industry.
Specifications of the material
EN material number: 1.4462
EN abbreviation: X2CrNiMoN22-5-3
EN standard: 10088-3
Microstructure class: Austenitic-ferritic duplex steel
Comparable standards and designations
AFNOR Z3CND22-05Az
AISI 318 LN
Alloy 2205
BS 318S13
ČSN 17381
GB 022Cr22Ni5Mo3N
JIS SUS329J3L
UNS S31803
RVS 318LN
SAE 318LN
SIS / SS 2333
Properties and chemical composition of stainless steel AISI 318LN / BS 318S13
C | Si | Mn | P | S | N | Cr | Cu | Mo | Ni | Ti |
|---|---|---|---|---|---|---|---|---|---|---|
≤ 0,03 | ≤ 1,00 | ≤ 2,00 | ≤ 0,035 | ≤ 0,015 | 0,10 - 0,22 | 21,0 - 23,0 | - | 2,50 - 3,50 | 4,50 - 6,50 | - |
Mass fraction in % according to DIN EN 10088-3
Abbreviations: C = carbon, Cr = chromium, Cu = copper, Mn = manganese, Mo = molybdenum, N = nitrogen, Ni = nickel, P = phosphorus, S = sulphur, Si = silicon, Ti = thallium.
Physical properties
Magnetisability: present
Density (kg/dm³): 7.8
Thermal conductivity (at 20°C): 15
Electrical resistance at room temperature (in Ω mm²/m): 0.80
Specific heat capacity (at 20°C): 500
Mechanical properties
These specifications refer to mechanical properties in the solution-annealed condition (+ AT) for ≤ 160 (Ø in mm) at room temperature in accordance with EN 10088-3.
Hardness in HB: ≤ 270
Yield strength Rp0.2 in Mpa: ≥ 450
Strength / tensile strength Rm in Mpa: 650 - 880 N/mm²
Elongation at break A in % (longitudinal): ≥ 25
AV in J (longitudinal): ≥ 100
The stainless steel AISI 318LN (1.4462, X2CrNiMoN22-5-3) can be used with many common welding methods such as ARC welding, WIG welding and laser welding. The material is not suitable for gas welding. To achieve a better phase distribution of the duplex steel, it is recommended to weld in the higher energy range of 1 to 3 (kJ/mm).
Forging
The austenitic-ferritic duplex steel AISI 318LN / BS 318S13 has medium forgeability. The material must first be heated slowly to a temperature of 1200°C so that the forging process can take place in the temperature range between 1200°C and 900°C. Subsequent rapid cooling in water or air is necessary. Open-hand forging and joint forging are possible.
Heat treatment and hot forming
Hot working (temperature 1200-950 °C) - cooling in air
Solution heat treatment (+AT) (temperature 1020-1100 °C) - cooling in air or in water
Note: Hot forming must be carried out over a temperature range of 600°C to 900°C, as this is where the sigma phase is formed, which has a negative effect on corrosion resistance.
Machinability and cold forming
Machinability: As an austenitic-ferritic duplex steel, the material AISI 318LN (1.4462, X2CrNiMoN22-5-3) has poor machinability. A shallower depth of cut should be selected than for austenitic stainless steels, but compared to these, machining the material is rather difficult.
Cold forming & cold heading: The material AISI 318LN / BS 318S13 is suitable for cold forming and cold mass forming (according to DIN EN 10263-5). The material is only partially suitable for cold heading.
Corrosion resistance
The duplex steel AISI 318LN (1.4462, X2CrNiMoN22-5-3) has a very good corrosion resistance (PREN value 30.9 - 38.0) in combination with organic acids, phosphoric acids and media containing chloride. Due to its austenitic-ferritic structure, the material is also resistant to stress corrosion cracking and intercrystalline corrosion. The resistance to intergranular corrosion is also maintained after welding. At room temperature, this material is also resistant to seawater, water vapour and nitric acid. Pitting can occur in conjunction with highly concentrated salt (NaCl).
Applications of stainless steel AISI 318LN / BS 318S13
Due to its strength and corrosion resistance, the duplex steel AISI 318LN (1.4462, X2CrNiMoN22-5-3) is suitable for a wide range of industrial applications. In the construction industry, this material is often used for architectural elements that are required to have a long service life even under unfavourable weather conditions. In the chemical industry, it is used to manufacture plant components, pipelines and containers. In the electronics and mechanical engineering industries, stainless steel AISI 318LN / BS 318S13 is used for enclosures that are exposed to the weather. Since this stainless steel is resistant to seawater, it is frequently used in shipbuilding. In offshore installations, stainless steel AISI 318LN is used for components that are exposed to extreme conditions. In the oil and petrochemical industry, the material is used for pipelines. Other areas of application include the food industry and the construction of seawater desalination plants and heat exchangers.
The data provided in this data sheet or material information sheet has been compiled to the best of our knowledge and is based on the current version of the relevant standard. We do not accept any liability for any errors.
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