X2CrNiMoN17-11-2 (1.4406 / 316LN) Open-Die Forgings
Forged bars, seamless rolled rings, flanges, discs, tube sheets, shafts and hollow bars in nitrogen-alloyed austenitic stainless steel. Made to EN 10088-3, EN 10250-4, EN 10222-5 and ASTM A182 F316LN.
Grade summary
X2CrNiMoN17-11-2 is the EN 10027-1 name for austenitic stainless steel number 1.4406. It is a low-carbon molybdenum grade, carbon capped at 0.030 %, with 0.12 to 0.22 % nitrogen added. That nitrogen puts the specified minimum proof strength at 280-315 MPa, about 40 % above 316L, and does not cost anything in resistance to intergranular corrosion. The grade is equivalent to AISI 316LN and UNS S31653.
Jiangyin Jiangnan Metal Co., Ltd. forges this grade into bars, seamless rolled rings, flanges, discs and hollow sections at its plant in Jiangyin, Jiangsu, China. Parts ship solution annealed with an EN 10204 3.1 certificate.
Quick reference
- EN name
- X2CrNiMoN17-11-2
- EN number
- 1.4406
- UNS
- S31653
- AISI / ASTM
- 316LN, A182 F316LN
- Microstructure
- Austenitic
- Density
- 8.0 g/cm³
- PREN
- 25.0 to 30.3
- Rp0.2 min
- 280 to 315 MPa
- Rm
- 580 to 800 MPa
- Min. service temp.
- -270 °C
- Magnetic
- No, μ approx. 1.005
- Delivery condition
- Solution annealed (+AT)
Figures are the limits given in EN 10088-1:2023 and EN 10088-3:2023 for grade 1.4406, with reference physical data from EN 10088-1 Annex E.
What is X2CrNiMoN17-11-2?
The EN 10027-1 name spells out the chemistry. X marks a high-alloy steel, 2 stands for 0.02 % nominal carbon, CrNiMoN lists the alloying elements in order of content, and 17-11-2 gives their nominal percentages: 17 % chromium, 11 % nickel, 2 % molybdenum. Nitrogen is in there but sits below the level that earns its own figure.
In practice the grade is 316L with nitrogen added on purpose. Nitrogen stabilises austenite and strengthens it in solid solution. At 0.12 to 0.22 % it takes the specified minimum yield from roughly 200 MPa on 316L up to 280-315 MPa, so a pressure part can be designed thinner for the same allowable stress. It also counts 16 times its weight percent in the PREN formula, and it slows sensitisation without adding the carbon that would throw chromium carbides out at the grain boundaries.
On heavy forgings this matters more than it does on sheet. A thick ring or tube sheet cools slowly through the sensitisation range after annealing. The low carbon ceiling working together with the nitrogen is what lets 1.4406 pass EN ISO 3651-2 intergranular corrosion testing both as delivered and after a sensitising treatment.
Equivalent grades
| System or country | Designation | Governing standard |
|---|---|---|
| EN (Europe), name | X2CrNiMoN17-11-2 | EN 10088-1:2023 |
| EN (Europe), number | 1.4406 | EN 10027-2 |
| AISI / ASTM (USA) | 316LN | ASTM A479 / A965 |
| UNS (USA) | S31653 | ISO 15510 |
| ASTM forgings (USA) | A182 Grade F316LN | ASTM A182 / A182M |
| JIS (Japan) | SUS316LN | JIS G 4303 |
| BS (UK, superseded) | 316S61 | BS 970 |
| AFNOR (France) | Z3CND17-11Az | NF A 35-573 |
| GB (China) | 022Cr17Ni12Mo2N | GB/T 1220, GB/T 20878 |
Cross-references are indicative. Composition limits differ between standards, so verify every element against the applicable specification before substituting a grade.
Product standards we forge this grade to
- EN 10250-4, open-die steel forgings for general engineering purposes, Part 4: stainless steels
- EN 10222-5, steel forgings for pressure purposes: martensitic, austenitic and austenitic-ferritic stainless steels
- EN 10088-3, bars, rods, sections and semi-finished products
- EN 10272, stainless steel bars for pressure purposes
- ASTM A182 / A182M, forged fittings, flanges and valve components, grade F316LN
- ASTM A965 / A479, forged or rolled bars for pressure vessel and high-temperature service
Chemical composition
| C | Si | Mn | P | S | Cr | Ni | Mo | N | Fe |
|---|---|---|---|---|---|---|---|---|---|
| max 0.030 | max 1.00 | max 2.00 | max 0.045 | max 0.015 | 16.5 to 18.5 | 10.0 to 12.5 | 2.0 to 2.5 | 0.12 to 0.22 | Balance |
- Sulphur can be set to suit the job. Controlled sulphur of 0.015 to 0.030 % machines better. 0.008 to 0.030 % gives a more consistent weld pool. Below 0.015 % polishes better. Tell us which one matters and the heat is picked to match.
- Phosphorus on PED work. Where the part falls under Pressure Equipment Directive 2014/68/EU, EN 10088-1 caps phosphorus at 0.035 %. We apply that tighter limit by default on PED orders.
- Elements not in the table are not added deliberately without the purchaser's agreement, apart from what is needed to finish the cast.
Mechanical properties
| Property | Symbol | Value | Test standard |
|---|---|---|---|
| Tensile strength | Rm | 580 to 800 MPa | EN ISO 6892-1 |
| 0.2 % proof strength, min. | Rp0.2 | 280 to 315 MPa | EN ISO 6892-1 |
| 1.0 % proof strength, min. | Rp1.0 | 315 to 355 MPa | EN ISO 6892-1 |
| Elongation at fracture, min. | A | 30 to 40 % transverse, 45 % longitudinal | EN ISO 6892-1 |
| Impact energy, longitudinal, +20 °C | KV | min 100 J | EN ISO 148-1 |
| Impact energy, transverse, +20 °C | KV | min 60 J | EN ISO 148-1 |
| Impact energy, transverse, -196 °C | KV | min 60 J | EN ISO 148-1 |
| Brinell hardness, max. | HBW | 250 | EN ISO 6506-1 |
Impact energy is the same at +20 °C and at -196 °C. Austenite has no transition temperature, which is the reason this grade goes into cryogenic work. Properties for sections above the standard ruling size are agreed at order stage. We test a prolongation from every heat-treatment lot.
Physical properties
| Property | Value at 20 °C |
|---|---|
| Density | 8.0 g/cm³ (8 000 kg/m³) |
| Modulus of elasticity | 200 GPa |
| Thermal conductivity | 15 W/(m·K) |
| Specific heat capacity | 500 J/(kg·K) |
| Electrical resistivity | 0.75 Ω·mm²/m |
| Thermal expansion, 20 to 200 °C | 16.5 × 10-6 K-1 |
| Relative magnetic permeability, annealed | approx. 1.005 |
Corrosion resistance and PREN
Pitting resistance equivalent number is PREN = %Cr + 3.3 × %Mo + 16 × %N. Applied to the composition limits of 1.4406:
| Grade | Mo, % | N, % | PREN range |
|---|---|---|---|
| 1.4404, 316L | 2.0 to 2.5 | max 0.11 | 23.1 to 28.5 |
| 1.4406, 316LN (this grade) | 2.0 to 2.5 | 0.12 to 0.22 | 25.0 to 30.3, typ. 27.5 |
| 1.4429, 316LN high-Mo | 2.50 to 3.00 | 0.12 to 0.22 | 26.7 to 31.9, typ. 29.3 |
- Intergranular corrosion. Passes in the delivery condition and after sensitisation, tested to EN ISO 3651-2.
- Pitting and crevice corrosion. Better than 304 / 1.4301 in chloride-bearing media. The nitrogen is worth roughly another 0.5 % molybdenum.
- Stress corrosion cracking. Like any standard austenitic, the risk climbs above about 60 °C in chloride solutions. If SCC governs the design, a duplex forging such as A182 F51 (1.4462) or F53 (2507) is the better choice.
- Minimum PREN on the order. We pick or order heats toward the top of the Cr, Mo and N ranges and put the calculated figure on the certificate.
Forging and heat treatment at our plant
| Operation | Parameter | Reason |
|---|---|---|
| Heating for forging | 1 150 to 1 200 °C | Dissolves ferrite stringers, gives even hot workability |
| Finish forging temperature | above 950 °C | Below this, chromium nitrides and sigma phase start to form and hot tearing risk climbs |
| Minimum forging ratio | 3:1 from ingot, 2:1 from billet | Closes porosity, refines the as-cast structure through the section |
| Solution annealing | 1 020 to 1 120 °C | Returns carbides and nitrides into solution |
| Cooling from anneal | Rapid quench in water | Clears the 550 to 900 °C sensitisation range fast enough to keep carbides out |
| Hardening | Not applicable | Austenitic. Strength comes from nitrogen in solid solution and from cold work |
| Stress relief after machining | Optional, 450 to 600 °C | By agreement only. Risks sensitising heavy sections, so normally left out |
Welding and machining
Welding
Welds with TIG, MIG, SMAW and SAW, no pre-heat and no post-weld heat treatment on most sections. Use a matching low-carbon filler, ER316LN or E316L, and hold interpass below about 150 °C. Heavy restrained joints do better with controlled heat input to keep distortion down.
Machining
Machines much like 316L but work hardens faster because of the nitrogen. Sharp positive-rake tooling, a rigid setup, heavy constant feeds and plenty of coolant. Do not let the tool dwell or the surface glazes. Where machinability governs, ask for a heat with controlled sulphur at 0.015 to 0.030 %.
Product forms in X2CrNiMoN17-11-2
| Product form | Typical size range | Supplied condition |
|---|---|---|
| Round bars and rods | Ø 80 to 1 200 mm, up to 6 000 mm long | Forged and solution annealed, black or rough turned |
| Square, flat and hex bars | 80 to 900 mm across flats | Forged and solution annealed, black or machined |
| Seamless rolled rings | OD 300 to 4 000 mm, height up to 1 200 mm | Ring rolled and solution annealed, rough machined |
| Forged rings | OD 200 to 2 500 mm | Forged and solution annealed |
| Forged flanges | ASME B16.5, B16.47, EN 1092-1, custom sizes | Forged and solution annealed, machined to drawing |
| Discs, blocks and tube sheets | Ø 200 to 3 000 mm, thickness 30 to 800 mm | Forged and solution annealed, rough machined |
| Hollow bars, sleeves, bushings, cylinders | OD 150 to 1 500 mm, ID from 80 mm | Forged, bored and solution annealed |
| Shafts and stepped shafts | up to 12 t single piece | Forged and solution annealed, rough machined |
Maximum single-piece weight 30 t. Machining allowance, ultrasonic acceptance class and surface condition are agreed per order and written on the certificate.
Where these forgings are used
Cryogenic equipment
LNG receiving terminals, liquid nitrogen and helium vessels, superconducting magnet structures. Specified for 60 J minimum impact energy down to -270 °C with no transition temperature.
Pressure vessels and heat exchangers
Tube sheets, channel covers, shell flanges and nozzle forgings. The higher proof strength allows thinner walls than 316L at the same allowable stress.
Chemical and petrochemical plant
Reactor internals, pump and valve bodies, agitator shafts and pipe fittings in chloride or acid service where sensitisation has to be kept out.
Offshore and marine
Seawater handling manifolds, subsea structural parts and topside piping components where weight and pitting resistance both count.
Nuclear and power
Primary circuit components and support structures specified as 316LN for low carbon, controlled nitrogen and stable behaviour under irradiation.
Pharmaceutical and food
Sanitary vessel flanges and fittings, using the 0.015 % max sulphur option for a clean polished finish.
Testing, inspection and certification
- Chemistry. Heat analysis by optical emission spectrometry, nitrogen by inert gas fusion. Product analysis on request.
- Mechanical testing. Tensile to EN ISO 6892-1, Charpy V-notch at +20 °C and on request at -196 °C or -269 °C to EN ISO 148-1, Brinell hardness to EN ISO 6506-1.
- Corrosion testing. Intergranular corrosion to EN ISO 3651-2 or ASTM A262 Practice E. ASTM G48 pitting test on request.
- Non-destructive examination. 100 % ultrasonic to EN 10228-3 or ASTM A388 at the agreed acceptance class, liquid penetrant to EN ISO 3452-1, PMI on every piece where specified.
- Documentation. EN 10204 3.1 inspection certificate as standard, covering heat analysis, heat-treatment chart, mechanical results, NDE report and dimensional record. 3.2 certification with a TUV, BV, SGS, DNV or Lloyd's Register witness when it is asked for at enquiry.
- Traceability. Heat number and lot number hard stamped or vibro etched on every piece and carried through to the certificate.
Frequently asked questions
Is X2CrNiMoN17-11-2 the same as 316L?
No. 1.4406 is the nitrogen-alloyed version of 316L (1.4404). Both hold carbon at 0.030 % max, but 1.4406 carries 0.12 to 0.22 % nitrogen. That lifts the specified minimum yield from about 200 MPa to 280-315 MPa and improves pitting resistance. Chromium, nickel and molybdenum ranges are close, so general corrosion behaviour is similar. The difference is strength and resistance to sensitisation.
What is the ASTM or AISI equivalent of X2CrNiMoN17-11-2?
1.4406 lines up with AISI 316LN, UNS S31653, ASTM A182 grade F316LN, JIS SUS316LN, BS 316S61, AFNOR Z3CND17-11Az and Chinese GB 022Cr17Ni12Mo2N. ISO 15510 lists 1.4406 under S31653 as well. Composition limits are not identical between standards, so check each element against the governing specification before approving a substitution.
What is the difference between 1.4406 and 1.4429?
Both are nitrogen-alloyed 316LN grades. 1.4406 runs 2.0-2.5 % Mo and 10.0-12.5 % Ni. 1.4429 (X2CrNiMoN17-13-3) runs 2.50-3.00 % Mo and 11.0-14.0 % Ni. The extra molybdenum puts the PREN of 1.4429 at 26.7-31.9 against 25.0-30.3 for 1.4406, so 1.4429 gets specified where chloride pitting risk is higher. Mechanical minima and low-temperature behaviour are close.
What is the PREN of X2CrNiMoN17-11-2?
Between 25.0 and 30.3 on the composition limits, with a mid-range figure near 27.5. Where a purchase specification calls for a minimum PREN, we select heats toward the top of the Cr, Mo and N ranges and report the calculated value on the EN 10204 certificate.
Can X2CrNiMoN17-11-2 be used at cryogenic temperatures?
Yes. Austenite has no ductile-to-brittle transition, and the grade holds a minimum transverse impact energy of 60 J at -196 °C. It is used down to -270 °C, which covers LNG, liquid nitrogen, liquid helium and superconducting magnet work. Charpy testing at -196 °C or -269 °C can be run on the heat-treatment lot when required.
Is X2CrNiMoN17-11-2 magnetic?
Solution annealed, it is effectively non-magnetic, with relative permeability around 1.005. Heavy cold work can form a little deformation martensite and push permeability up slightly, though the nitrogen stabilises the austenite and the effect is smaller than on 304. If a maximum permeability has to be guaranteed, state the limit at enquiry so it can be checked before despatch.
What forging and heat-treatment parameters do you use?
Ingot or billet goes in at 1 150 to 1 200 °C, is forged at a minimum 3:1 reduction and finished above 950 °C so that sigma phase and chromium nitrides do not form. Parts are then solution annealed at 1 020 to 1 120 °C and water quenched. The grade cannot be hardened by heat treatment. Its strength comes from nitrogen in solid solution.
What certification comes with the forgings?
An EN 10204 3.1 inspection certificate as standard, covering heat analysis, the solution-annealing record, tensile and impact results, hardness, ultrasonic examination to the agreed acceptance class and a dimensional report. EN 10204 3.2 certification with a third-party witness such as TUV, BV, SGS, DNV or Lloyd's Register is available if it is asked for at enquiry.
What is your minimum order quantity and lead time?
We are the forging plant, so single pieces and prototypes are accepted and there is no tonnage minimum on a machined forging. Lead time normally runs 25 to 40 days from order confirmation on items forged from stock billet, longer when a dedicated heat has to be melted. Firm dates come with the quotation.
How do I request a quotation?
Send the drawing or the finished dimensions, quantity, applicable specification, certification required and any NDE class to sales@steelforgepieces.com, or call +86 189 2135 9659. A price and delivery date normally come back within one working day.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging plant at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. It sits inside the Yangtze delta forging cluster, about 150 km from the Port of Shanghai.
We forge bars, seamless rolled rings, flanges, discs, tube sheets, shafts and hollow sections in stainless steel, nickel alloy, alloy steel, tool steel and carbon steel. Material is certified to EN, ASTM, ASME, DIN, JIS and GB specifications and goes to pressure vessel, petrochemical, cryogenic, marine and power customers worldwide.
Because the forging is done here rather than bought in, heat selection, forging ratio, heat-treatment cycle, NDE class and machining allowance all stay under one roof and are recorded against a single heat number.
Request a quotation
Send a drawing or your finished dimensions, quantity, specification and certification requirement. A price and delivery date normally come back within one working day.
- Company
- Jiangyin Jiangnan Metal Co., Ltd.
- Telephone, WhatsApp, WeChat
- +86 189 2135 9659
- sales@steelforgepieces.com
- Plant address
- No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Related stainless steel forging grades
- A182 F316L (1.4404), the base grade without nitrogen, for jobs where the higher proof strength of 316LN is not needed.
- A182 F51 (1.4462 / 2205 duplex), roughly double the proof strength and much better chloride SCC resistance.
- A182 F53 (2507 super duplex), PREN above 40 for aggressive seawater service.
- A182 F44 (1.4547 / 254 SMO), 6 % Mo super-austenitic for the worst chloride pitting duty.
- 904L (1.4539), high-nickel austenitic for sulphuric and phosphoric acid service.
- Nitronic 50 (XM-19 / S20910), high-nitrogen austenitic where more strength again is needed.
Data on this page is taken from EN 10088-1:2023, EN 10088-3:2023, EN 10250-4, EN 10222-5, ASTM A182/A182M and ISO 15510, together with our own production practice. Figures are for guidance. What governs any order is the applicable specification and the material certificate. Page last reviewed .