X3CrNiMo18-12-3 (1.4449) Forgings
Austenitic Cr-Ni-Mo stainless forging grade to EN 10088-1 and EN 10222-5. Forged rings, flanges, shafts, discs and bars from an open-die forging factory in Jiangyin, China.
X3CrNiMo18-12-3, material number 1.4449, is a molybdenum-bearing austenitic chromium-nickel stainless steel. It is listed in EN 10088-1 and specified as a stainless austenitic steel forging grade for pressure purposes in EN 10222-5. Composition limits are 17.0 to 18.2 % Cr, 11.5 to 12.5 % Ni, 2.25 to 2.75 % Mo and max 0.035 % C, giving a PREN of about 27. In alloy content it sits between 316L and 317L, and it is cross-referenced to UNS S31700 and ASTM A965 F317 as a nearest equivalent rather than an identical grade.
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, manufactures 1.4449 as forged rings, seamless rolled rings, flanges, shafts, discs, sleeves, bushings, tube sheets and round bars to customer drawing, with ultrasonic examination to EN 10228-3, SEP 1921 or ASTM A388 and certification to EN 10204 3.1 or 3.2. Enquiries: sales@steelforgepieces.com, +86-189-2135-9659.
1. Grade overview
1.4449 belongs to the molybdenum-alloyed austenitic family. Molybdenum raises resistance to pitting and crevice attack in chloride and halide bearing media compared with plain 18/8 grades, while the low carbon maximum of 0.035 % limits chromium carbide precipitation and therefore the risk of sensitisation during welding and other thermal processing. The steel is non-magnetic in the annealed condition, cannot be hardened by heat treatment, and gains strength only through cold work.
2. Chemical composition
| C | Si | Mn | P | S | Cr | Ni | Mo | Cu | N | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| 0.035 | 1.00 | 2.00 | 0.045 | 0.015 | 17.0-18.2 | 11.5-12.5 | 2.25-2.75 | 1.00 | 0.08 | Balance |
Source: EN 10088-1 and NF EN 10088-1:2005 composition listing for 1.4449. A second materials database quotes Mo as 2.3 to 2.8 % and Fe as 62.4 to 69.3 %, which agrees within rounding. Elements not listed shall not be intentionally added without the agreement of the purchaser.
3. Mechanical properties
The values below are typical for the solution annealed condition and are intended for design screening. Acceptance values for a given forging are taken from the governing order standard and the section thickness.
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength, ultimate | 620 MPa | 90 ksi |
| Yield strength, proof | 250 MPa | 36 ksi |
| Elongation at break | 48 % | 48 % |
| Impact, Charpy V-notch | 91 J | 67 ft-lb |
| Hardness, Brinell | 190 HB | 190 HB |
| Fatigue strength | 240 MPa | 35 ksi |
| Shear strength | 440 MPa | 64 ksi |
| Young's modulus | 200 GPa | 29 x 10⁶ psi |
| Shear modulus | 78 GPa | 11 x 10⁶ psi |
| Poisson's ratio | 0.28 | 0.28 |
Source: materials database values for EN 1.4449 in the solution annealed condition. These figures do not replace certified mill test values.
4. Physical properties
| Property | Value |
|---|---|
| Density | 7.9 g/cm³, EN listings also quote 8 g/cm³ |
| Melting range | 1400 °C solidus to 1440 °C liquidus |
| Thermal conductivity | 15 W/(m·K) |
| Specific heat capacity | 470 J/(kg·K) |
| Thermal expansion | 16 µm/(m·K) |
| Maximum service temperature, corrosion limited | approx. 410 °C |
| Maximum service temperature, mechanically limited | approx. 960 °C |
| Electrical conductivity | 2.3 % IACS, equal volume |
| Magnetic response | Non-magnetic in the annealed condition |
| PREN, Cr + 3.3Mo + 16N | approx. 27 |
Source: materials database entry for EN 1.4449. PREN formula as used in published 317 family datasheets.
5. Equivalent designations and standards
| Region | Standard | Designation |
|---|---|---|
| Europe | EN 10088-1 | X3CrNiMo18-12-3 / 1.4449 |
| Europe | EN 10222-5, forgings for pressure purposes | X3CrNiMo18-12-3 / 1.4449 |
| Germany | AD 2000 W 2 | X3CrNiMo18-12-3 |
| International | ISO 9327-5 | X5CrNiMo17-3 |
| International | ISO 15510 | 4449-316-76-E |
| Japan | JIS G 3214 | SUSF317 |
| South Korea | KS D 4115 | STSF317 |
| USA | ASTM A965 | Grade F317 |
| USA | UNS | S31700, nearest |
Source: Applus materials datasheet for 1.4449 to DIN EN 10222-5:2017-06, cross-references per Stahlschlüssel 2016.
6. How 1.4449 compares with neighbouring grades
Grade names in this family are easily confused. 1.4449, X3CrNiMo18-12-3, is a different steel from 1.4436, X3CrNiMo17-13-3, and both differ from 1.4438, the EN number usually matched to 317L.
| Grade | Number | C | Cr | Ni | Mo | Listed in |
|---|---|---|---|---|---|---|
| X3CrNiMo18-12-3 | 1.4449 | 0.035 | 17.0-18.2 | 11.5-12.5 | 2.25-2.75 | EN 10088-1, EN 10222-5 |
| X2CrNiMo17-12-2, 316L | 1.4404 | 0.030 | 16.5-18.5 | 10.0-13.0 | 2.00-2.50 | EN 10088-3 |
| X3CrNiMo17-13-3 | 1.4436 | 0.05 | 16.5-18.5 | 10.5-13.0 | 2.50-3.00 | EN 10088-3 |
| X2CrNiMo18-14-3 | 1.4435 | 0.030 | 17.0-19.0 | 12.5-15.0 | 2.50-3.00 | EN 10088-3 |
| X2CrNiMo18-15-4, close to 317L | 1.4438 | 0.030 | 17.5-19.5 | 13.0-16.0 | 3.0-4.0 | EN 10088-3 |
| X2CrNiMoN17-13-5 | 1.4439 | 0.030 | 16.5-18.5 | 12.5-14.5 | 4.0-5.0 | EN 10088-3 |
Source: British Stainless Steel Association tabulation of EN 10088-3 chemical compositions for 1.4404, 1.4435, 1.4436, 1.4438 and 1.4439. 1.4449 per EN 10088-1.
One point that is often missed: 1.4449 does not appear in the EN 10088-3 austenitic tables at all. EN 10088-3 governs semi-finished products, bars, rods and sections for general purposes, whereas 1.4449 sits in the EN 10088-1 list and in EN 10222-5 for pressure purpose forgings. That is why the grade is normally bought as a forging rather than from a bar stockist, and why an open-die forge is the natural source of supply.
7. Corrosion behaviour
Molybdenum-bearing austenitics of this type give better general and localised corrosion resistance than 304 and 304L in most media, with improved performance relative to leaner grades in sulfurous media, chlorides and other halides. The low carbon level supports use in the as-welded condition without post-weld annealing in many applications.
Two limits should be designed around. Strongly oxidising acids such as nitric acid are an exception, since molybdenum-bearing alloys generally perform less well there than molybdenum-free grades. Austenitic stainless steels also remain susceptible to chloride stress corrosion cracking; higher molybdenum improves resistance but does not remove the mechanism. Where chloride cracking or severe pitting governs, consider duplex grades such as F51, F53 or F55, or higher alloyed austenitics such as 904L and F44, all of which we also forge.
Corrosion behaviour described from published 317 and 317L datasheet guidance for the molybdenum-bearing austenitic family. Verify against your service chemistry.
8. Forging, heat treatment and machining
Our route for this grade is EAF plus VOD melting, with ESR available where the order calls for improved cleanliness and segregation control, followed by open-die forging or ring rolling to shape and a solution anneal with rapid quench.
Hot working
Published practice for the 317 type family is 900 to 1150 °C with no working below 950 °C. If final forming falls below that limit, a solution anneal is required.
Solution anneal
Heat, hold and rapid quench to restore the austenitic structure and dissolve carbides. The exact window is confirmed against the order standard for the section size.
Hardening
Not hardenable by heat treatment. Strength is raised only by cold work. The alloy is otherwise ductile and forms readily.
Machining
The work-hardening rate makes these grades less machinable than martensitic 410. Use rigid setups and positive feeds, and avoid dwelling in the cut.
Welding
Low carbon limits sensitisation. Standard processes apply and post-weld heat treatment is generally not required for L type 317 family material.
Supply condition
Normally delivered solution annealed, non-magnetic, with mill certification to EN 10204.
Hot working and fabrication guidance reflects published datasheet practice for the 317 and 317L family of molybdenum-bearing austenitics. Parameters for a specific 1.4449 forging are set against the applicable order standard and section thickness.
9. X3CrNiMo18-12-3 forged products we manufacture
All shapes are produced to customer drawing or specification by open-die forging and ring rolling at our Jiangyin plant. Finished weights, ring diameters and wall thicknesses are quoted against the drawing.
Forged and rolled rings
Seamless rolled rings and forged rings, plain or profiled, for flanged and bolted joints.
Forged flanges
Weld neck, blind, slip-on and special profile flanges, machined or rough turned.
Shafts and spindles
Forged shafts, eccentric shafts, spindles and crankshaft blanks for rotating equipment.
Discs and disks
Forged discs and blanks for closures, covers, gear blanks and wheel bodies.
Sleeves and bushings
Forged sleeves, bushings and hollow forgings, bored and trepanned as required.
Bars and blocks
Forged round bars, square bars, rectangular blocks and step forged preforms.
Tube sheets and nozzles
Forged tube sheets, tube plates, nozzles and manifold bodies for exchangers and vessels.
Valve components
Forged valve bodies, bonnets, stems, seat rings and blocks for ball, gate, globe, check and plug valves.
10. Typical applications
Molybdenum-bearing austenitics of this class are specified where 304 and 304L are not sufficient but a duplex or super-austenitic grade is not warranted. Published application areas for the 317 family include air pollution control and flue gas desulfurisation systems, chemical and petrochemical processing, petroleum refining, pulp and paper, food and beverage processing, and power generation condensers. In forged form the grade is commonly used for pressure retaining components such as vessel and exchanger flanges, tube sheets, nozzles, valve bodies, and pump and agitator shafts.
11. Testing, inspection and certification
Ultrasonic examination
To EN 10228-3, SEP 1921 or ASTM A388, to the acceptance class stated on the order.
Material certification
EN 10204 3.1 mill certificate, or 3.2 with third party endorsement on request.
Chemical analysis
Ladle and product analysis against EN 10088-1 and EN 10222-5 limits.
Mechanical testing
Tensile, impact and hardness testing at specified locations and orientations.
Corrosion testing
Intergranular corrosion testing to the ASTM A262 practice specified, on request.
Dimensional and NDT
Dimensional reports, positive material identification, liquid penetrant and magnetic particle where applicable.
12. Frequently asked questions
What is X3CrNiMo18-12-3 (1.4449)?
A molybdenum-bearing austenitic chromium-nickel stainless steel listed in EN 10088-1 and specified as a stainless austenitic steel forging grade for pressure purposes in EN 10222-5. Composition limits are 17.0 to 18.2 % Cr, 11.5 to 12.5 % Ni, 2.25 to 2.75 % Mo and max 0.035 % C.
Is 1.4449 the same as 317 or UNS S31700?
Not identical. Stahlschlüssel cross-references 1.4449 to UNS S31700, ASTM A965 Grade F317, JIS SUSF317 and KS STSF317. ASTM 317 type grades specify 3.0 to 4.0 % Mo and 11.0 to 15.0 % Ni, while EN 1.4449 is leaner at 2.25 to 2.75 % Mo and 11.5 to 12.5 % Ni. Treat S31700 as the nearest equivalent and name the governing standard on the order.
Why can I not find 1.4449 in the EN 10088-3 bar tables?
EN 10088-3 covers bars, rods and sections for general purposes and does not include 1.4449 among its austenitic grades. The grade appears in the EN 10088-1 list of stainless steels and in EN 10222-5 for pressure purpose forgings, so it is normally sourced as a forging.
What heat treatment do X3CrNiMo18-12-3 forgings receive?
Solution annealing with rapid quench, supplied in condition +AT. The grade cannot be hardened by heat treatment. For the 317 type family, published practice is hot working at 900 to 1150 °C with no working below 950 °C, followed by a solution anneal and rapid quench where the final forming temperature falls below that limit.
Is 1.4449 suitable for seawater or high chloride service?
With a PREN of about 27 it offers better pitting resistance than 316L but remains susceptible to chloride stress corrosion cracking, and it is well below the PREN of roughly 40 and above usually sought for seawater. For those duties we would point you to duplex and super duplex forgings such as F51, F53 and F55, or to F44 and 904L.
What forged shapes and certification are available, and what is the lead time?
Jiangyin Jiangnan Metal Co., Ltd. manufactures this grade as open-die forgings and seamless rolled rings at its plant at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, with ultrasonic examination to EN 10228-3, SEP 1921 or ASTM A388 and certificates to EN 10204 3.1 or 3.2. Send a drawing, or the size, quantity and governing standard, to sales@steelforgepieces.com or call +86-189-2135-9659 for a quotation and current lead time.
Request a quotation for X3CrNiMo18-12-3 forgings
Send the drawing or the finished size, quantity, governing standard and required certification. We will reply with price, weight and lead time.
Open-Die Forging Factory
Jiangyin City, Jiangsu Province, China
Related stainless forging grades
Product routes: forged rings, forged bars, forged spindles.
Data sources
- EN 10088-1 and NF EN 10088-1:2005, Stainless steels, Part 1: List of stainless steels. Composition limits for 1.4449.
- DIN EN 10222-5:2017-06, Steel forgings for pressure purposes, Part 5: Martensitic, austenitic and austenitic-ferritic stainless steels. Cross-reference table per Stahlschlüssel 2016, Verlag Stahlschlüssel Wegst GmbH, Marbach.
- BS EN 10088-3 chemical composition tables, British Stainless Steel Association. Comparison grades 1.4404, 1.4435, 1.4436, 1.4438 and 1.4439.
- Published 317 and 317L specification sheet, UNS S31700 and S31703. Corrosion behaviour, PREN formula, hot working and fabrication guidance for the molybdenum-bearing austenitic family.
- Materials property database entry for EN 1.4449, X3CrNiMo18-12-3, solution annealed condition.
Technical content reviewed by the engineering department of Jiangyin Jiangnan Metal Co., Ltd. Last updated 9 October 2026. The data is given for guidance. It does not replace the governing standard or a certified mill test report, and it is not a warranty of fitness for any particular application.