# 1.4940 (X7CrNiTi18-10) Forgings, 321H / UNS S32109 Equivalent

Author: Technical department, Jiangyin Jiangnan Metal Co., Ltd.
Published: 2026-09-27. Last reviewed: 2026-09-27.
Canonical page: https://www.steelforgepieces.com/Stainless-Steel/1.4940.html

1.4940 / X7CrNiTi18-10 is a titanium-stabilised 18-10 austenitic creep resisting
stainless steel. Its closest commercial counterpart is 321H, UNS S32109.
Jiangyin Jiangnan Metal Co., Ltd. melts, forges, heat treats, machines and certifies
it in one works in Jiangyin, Jiangsu, China. Single pieces up to 30 tonnes from heats
up to 60 tonnes, EN 10204 3.1 certification as standard and 3.2 witnessed on request.
Class approvals CCS, BV, DNV, LR, NK.

Contact: +86 189 2135 9659, sales@steelforgepieces.com,
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China.
Monday to Saturday, 08:00 to 17:30 China Standard Time, UTC+8.

## Designation

| Field | Detail |
|---|---|
| EN material number | 1.4940 |
| EN designation | X7CrNiTi18-10 |
| Classification | Austenitic creep resisting steel |
| Density | 7.9 g/cm3 |
| Standards carrying 1.4940 | EN 10216-5:2014 seamless tube, EN 10088-1:2005 |
| Nearest ASTM and UNS | A182 F321H, A213 Type 321H, UNS S32109, AISI 321H, SUS 321H |
| EN forging counterpart | X6CrNiTiB18-10 (1.4941), listed in EN 10222-5 |
| Strengthening | Solution treatment and quench only, cannot be age hardened |

Two corrections to figures that circulate widely: 1.4940 is classified as a creep
resisting steel, not a general purpose austenitic grade, and it cannot be given a
solution plus ageing treatment, because the 321 and 321H family cannot be hardened by
thermal treatment at all.

## Which standard governs a forging

1.4940 is not a grade in EN 10222-5, the European standard for steel forgings for
pressure purposes. The titanium-stabilised 18-10 grade there is the boron bearing
X6CrNiTiB18-10 (1.4941), listed with X7CrNiNb18-10 (1.4912) and X6CrNi18-10 (1.4948).
Three deliverable routes exist: ASTM A182 F321H / UNS S32109, where A182 limits single
pieces to 4540 kg and directs heavier austenitic forgings to A965/A965M; EN 10222-5
grade 1.4941; or 1.4940 chemistry per EN 10216-5 applied to a forging by agreement and
stated as such on the certificate.

## Composition, percent by mass

| Element | 1.4940 (EN 10216-5) | A182 F321H | 1.4941 |
|---|---|---|---|
| C | 0.04 to 0.08 | 0.04 to 0.10 | 0.040 to 0.080 |
| Si | 1.00 max | 1.00 max | 1.0 max |
| Mn | 2.00 max | 2.00 max | 2.0 max |
| P | 0.040 max | 0.045 max | 0.035 max |
| S | 0.015 max | 0.030 max | 0.015 max |
| Cr | 17.0 to 19.0 | 17.0 to 19.0 | 17 to 19 |
| Ni | 9.0 to 13.0 | 9.0 to 12.0 | 9.0 to 12 |
| Ti | 0.20 to 0.80, 5x(C+N) < Ti < 0.8 | not less than 4xC, 0.70 max; some editions 4x(C+N) | 0.40 to 0.80 |
| N | 0.10 max | no requirement | no requirement |
| B | no requirement | no requirement | 0.0015 to 0.0050 |
| Fe | balance | balance | balance |

Boron is the defining difference in 1.4941 and is absent from 1.4940 and F321H.
Datasheets showing 1.4940 with titanium 0.35 and tensile 480 MPa have been taken from
a generic 321H table, not from EN 10216-5.

## Mechanical properties, solution annealed

| Property | 1.4940 (EN 10216-5, +AT) | A182 F321H minima | 1.4941 typical |
|---|---|---|---|
| Tensile Rm | 510 to 710 MPa | 515 MPa min | 590 MPa |
| 0.2 percent proof Rp0.2 | 190 MPa min | 205 MPa min | 210 MPa |
| Elongation A | 35 percent long., 30 percent transv. | 30 percent min | 39 percent |
| Reduction of area | no requirement | 50 percent min | not stated |
| Impact KV at +20 C | 100 J long., 60 J transv. | no requirement | 98 J |
| Hardness Brinell | no requirement | no requirement | 180 |
| Modulus of elasticity | not stated | not stated | 200 GPa |

The 1.4941 column holds typical published values and is not acceptance criteria.

## Heat treatment

| Operation | Parameters | Source |
|---|---|---|
| Cooling after hot working | below 538 C before heat treating | ASTM A182 cl. 7.1 |
| Solution treat and quench, F321H | 1095 C min, liquid, cool below 260 C | A182 Table 1 |
| Solution treat and quench, F321 | 1040 C min, liquid, cool below 260 C | A182 Table 1 |
| Solution anneal, 321 and 321H generally | 950 to 1120 C, cool rapidly | grade 321 and 347 data |
| Stabilising anneal | 870 to 900 C, 1 h per 25 mm, air cool | grade 321 and 347 data |
| Stress relief | 700 C, 1 to 2 h, air cool | grade 321 data |
| Ageing | not applicable, cannot be hardened thermally | grade 321 and 347 data |

F321 and F321H are excluded from the in line rapid quench alternative in A182 clause
7.3.1, so a separate furnace cycle is required. A182 warns that solution annealing
above 1065 C may impair intergranular corrosion resistance after later sensitising
exposure, while the F321H minimum is 1095 C. Supplementary requirement S10 provides for
a lower temperature stabilisation or a re-solution anneal. Heat treatment is carried
out in fourteen furnaces on site, including car bottom furnaces for rings, discs and
tube sheets and well type furnaces for vertical quenching of long shafts.

## Behaviour and limits

Titanium ties up carbon so that chromium carbide does not precipitate in the carbide
precipitation range, published as 425 to 850 C for 321 and 347 and 427 to 816 C for
321H. Oxidation resistance is good to 900 C intermittent and 925 C continuous. 321H
has higher hot strength than 321. Limits: pitting and crevice corrosion in warm
chlorides, stress corrosion cracking above about 60 C, and above roughly 1100 C the
grade is out of range, where 310 or S30815 applies.

On intergranular corrosion the record is inconsistent. steelnumber lists 1.4940 as not
resistant under EN 10216-5 and 1.4941 as resistant both as delivered and sensitised
under EN 10028-7. Order ASTM A262 testing where the service case depends on it.

Not claimed, because it is not supported by the sources below: resistance in
hydrofluoric acid or fluorine, and resistance to hot strong alkali. For hydrofluoric
service ask about the nickel alloys.

Welding: titanium does not transfer across a high temperature arc, so grade 347 is the
standard filler for welding 321. Post weld annealing is not required.

## Products

| Product | Notes |
|---|---|
| Seamless rolled rings, contoured rings, bearing races, slewing and yaw rings | 6 m radial axial ring mill |
| Forged rings, gear rings, retaining rings, valve seat rings | 6300 t press for sections outside ring mill range |
| Forged flanges, weld neck, blind, slip on, socket weld, lap joint, orifice | ASME B16.5, B16.47, API 6A. A182 limits single pieces to 4540 kg |
| Forged shafts, spindles, rolls, rotors, tie rods | vertical quenching in well type furnaces |
| Tube sheets, discs, covers, hubs | as forged or proof machined for UT |
| Forged bars and blocks, round, flat, square | to drawing |
| Cylinders, sleeves, bushings, heavy wall pipe sections | CNC deep hole drilling |
| Valve and wellhead parts | API 6A, NACE MR0175 / ISO 15156 where specified |
| Single piece weight | up to 30 tonnes, from heats up to 60 tonnes |

ASTM A182 restricts products made to it to 10 000 lb, 4540 kg, and directs larger
austenitic forgings to A965/A965M, so heavy 321H rings and tube sheets are inside our
range but outside the scope of A182.

## Melting route

Carbon, alloy, stainless and duplex grades run through the electric arc furnace, the
ladle furnace and vacuum oxygen decarburisation, the route used where low carbon and
controlled nitrogen are needed, as they are for 1.4940 with its 0.08 percent carbon and
0.10 percent nitrogen ceilings. Maximum heat size is 60 tonnes. Clean and superalloy
grades take the vacuum induction, vacuum arc and protective atmosphere electroslag
remelting routes. The titanium to carbon plus nitrogen ratio that EN 10216-5 writes as
5x(C+N) < Ti < 0.8 is set in the melt shop, so traceability runs from the melt number
through forging, heat treatment and machining to shipment.

## Testing and certification

CCS, BV, DNV, LR and NK class approvals. Optical emission spectrometry to ASTM E415,
carbon and sulfur to ASTM E1019, positive material identification, tensile to
ASTM A370 and ISO 6892, Charpy V notch, grain size to ASTM E112, ultrasonic testing to
ASTM A388 and EN 10228-3, magnetic particle to ASTM E709 where applicable. ASTM A262,
G28, G48, low temperature impact and bench hardness are placed with accredited
laboratories. EN 10204 3.1 as standard, 3.2 witnessed by BV, DNV, LR, SGS, TUV or the
customer's inspector on request.

## Request a quotation

Open die work has no list price. Cost follows finished weight, input weight after
machining allowance, the number of heating and forging operations, the heat treatment
cycle and the testing scope. Email sales@steelforgepieces.com with the grade and
governing standard, the dimensions or drawing, the quantity and repeat volume, the
delivery condition, the heat treatment and testing scope, and the certification and
destination port.

## Sources

EN 10216-5:2014, EN 10088-1:2005, EN 10222-5, EN 10302:2008, EN 10028-7,
ASTM A182/A182M, published grade datasheets for 321 (S32100) and 321H (S32109),
Applus Laboratories materials portal datasheet X7CrNiTi18-10 / 1.4940,
steelnumber.com entries for 1.4940 and 1.4941 and the equivalence table for S32109,
MakeItFrom record for EN 1.4941 (X6CrNiTiB18-10).

Reviewed 2026-09-27. Indicative data, not a replacement for the governing standard or
an agreed order specification.