---
title: "X3CrNiMo18-12-3 (1.4449) Forgings: Rings, Flanges, Bars"
grade: X3CrNiMo18-12-3
material_number: "1.4449"
nearest_uns: S31700
standards: [EN 10088-1, EN 10222-5, ASTM A965 F317, JIS SUSF317, KS STSF317]
manufacturer: Jiangyin Jiangnan Metal Co., Ltd.
address: No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
phone: "+86-189-2135-9659"
email: sales@steelforgepieces.com
canonical: https://www.steelforgepieces.com/Stainless-Steel/X3CrNiMo18-12-3.html
updated: 2026-10-09
---

# 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.

**Note on published composition data.** Figures of 16.0 to 18.0 % Cr, 4.00 to 5.00 % Mo and 12.5 to 14.5 % Ni have circulated for this grade. They do not belong to 1.4449; they match X2CrNiMoN17-13-5 (1.4439) in the EN 10088-3 table. The composition below follows EN 10088-1 and supersedes those values.

## 2. Chemical composition

Composition limits, % by mass. Single values are maxima.

| 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 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

Typical room temperature values, solution annealed (+AT). For design screening only; acceptance values come from the governing order standard and 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 10^6 psi |
| Shear modulus | 78 GPa | 11 x 10^6 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 um/(m K) |
| Max service temperature, corrosion limited | approx. 410 C |
| Max 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 Stahlschluessel 2016.

**1.4449 is not a drop-in replacement for ASTM 317.** ASTM 317 type grades carry 3.0 to 4.0 % Mo and 11.0 to 15.0 % Ni, giving a PREN near 30, whereas EN 1.4449 is leaner at 2.25 to 2.75 % Mo with a PREN of about 27. In chloride service that difference matters. State the governing standard, EN 10222-5 or ASTM A965, on the purchase order.

## 6. Comparison with neighbouring grades

Single values are maxima.

| 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 compositions. 1.4449 per EN 10088-1.

1.4449 does not appear in the EN 10088-3 austenitic tables at all. EN 10088-3 governs bars, rods and sections for general purposes, whereas 1.4449 sits in EN 10088-1 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.

## 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 F51, F53 or F55, or higher alloyed austenitics such as 904L and F44.

## 8. Forging, heat treatment and machining

Route: 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 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. Hardening: not possible by heat treatment; strength is raised only by cold work. Machining: the work-hardening rate makes these grades less machinable than martensitic 410. Welding: low carbon limits sensitisation, and post-weld heat treatment is generally not required for L type 317 family material. Supply condition: solution annealed, non-magnetic, with mill certification to EN 10204.

## 9. Forged products manufactured in this grade

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 rings and seamless rolled rings, plain or profiled. Forged flanges: weld neck, blind, slip-on and special profiles. Forged shafts, eccentric shafts, spindles and crankshaft blanks. Forged discs and blanks for closures, covers, gear blanks and wheel bodies. Forged sleeves, bushings and hollow forgings, bored and trepanned. Forged round bars, square bars, rectangular blocks and step forged preforms. Forged tube sheets, tube plates, nozzles and manifold bodies. Forged valve bodies, bonnets, stems, seat rings and blocks for ball, gate, globe, check and plug valves.

## 10. Typical applications

Grades 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 to EN 10204 3.1, or 3.2 with third party endorsement on request. Ladle and product chemical analysis against EN 10088-1 and EN 10222-5 limits. Tensile, impact and hardness testing at specified locations and orientations. Intergranular corrosion testing to the ASTM A262 practice specified. Dimensional reports, positive material identification, liquid penetrant and magnetic particle inspection 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. Stahlschluessel 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. 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 EN 10088-1 and in EN 10222-5 for pressure purpose forgings, so it is normally sourced as a forging.

**What heat treatment do these forgings receive?**
Solution annealing with rapid quench, 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 final forming 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 consider duplex and super duplex forgings F51, F53 and F55, or 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.

## Contact

Jiangyin Jiangnan Metal Co., Ltd., Open-Die Forging Factory
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China
Phone +86-189-2135-9659
Email sales@steelforgepieces.com

## Data sources

1. EN 10088-1 and NF EN 10088-1:2005, Stainless steels, Part 1: List of stainless steels. Composition limits for 1.4449.
2. DIN EN 10222-5:2017-06, Steel forgings for pressure purposes, Part 5. Cross-reference table per Stahlschluessel 2016.
3. BS EN 10088-3 chemical composition tables, British Stainless Steel Association. Comparison grades 1.4404, 1.4435, 1.4436, 1.4438, 1.4439.
4. Published 317 and 317L specification sheet, UNS S31700 and S31703, for corrosion behaviour, PREN formula and fabrication guidance.
5. Materials property database entry for EN 1.4449, solution annealed condition.

Reviewed by the engineering department of Jiangyin Jiangnan Metal Co., Ltd. Last updated 9 October 2026. Data is given for guidance; it does not replace the governing standard or a certified mill test report.