X12CrNiTi18-9 Forgings (W.-Nr. 1.4878 / AISI 321H / UNS S32109)
Titanium-stabilised austenitic heat-resistant stainless steel. Forged rings, seamless rolled rings, flanges, discs, shafts, sleeves and tube sheets made to drawing by Jiangyin Jiangnan Metal Co., Ltd.
Published | Updated | Jiangyin Jiangnan Metal Co., Ltd.
Grade summary
X12CrNiTi18-9 is the older German designation for a titanium-stabilised austenitic heat-resistant stainless steel carried under Werkstoff number 1.4878 and listed alongside X8CrNiTi18-10 in EN 10095. The ASTM counterpart is AISI 321H (UNS S32109). Composition is 17.0 to 19.0 % Cr and 9.0 to 12.0 % Ni, with titanium at 5×C up to 0.8 %. It resists scaling in air to roughly 850 °C and is supplied solution annealed at 1020 to 1120 °C. Jiangyin Jiangnan Metal Co., Ltd. forges this grade to customer drawings at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin, Jiangsu, China (0086-189-2135-9659, sales@steelforgepieces.com).
- 1.4878
- X8CrNiTi18-10
- AISI 321H
- UNS S32109
- TP321H
- 12Ch18N10T
- 1H18N9T
1. Grade identity and equivalent designations
X12CrNiTi18-9 belongs to the heat-resistant, titanium-stabilised 18/10 austenitic family. The same Werkstoff number, 1.4878, is written X8CrNiTi18-10 in current European practice, so a drawing calling for X12CrNiTi18-9, X8CrNiTi18-10 or 321H is normally satisfied by one material. Where a print still carries the older name, we quote and certify against 1.4878.
| Standard or region | Designation |
|---|---|
| EN / DIN (Werkstoff) | 1.4878 |
| EN 10095 name | X8CrNiTi18-10 |
| Older German designation | X12CrNiTi18-9 |
| ASTM / AISI | AISI 321H, TP321H |
| UNS | S32109 |
| PN (Poland) | 1H18N9T |
| GOST | 12Ch18N10T |
| Closest low-carbon grade | 1.4541 / X6CrNiTi18-10 / AISI 321 (UNS S32100) |
Note. 1.4878 and 1.4541 are both titanium stabilised, but 1.4878 runs a higher carbon content, which lifts its creep strength. 1.4878 is therefore the grade picked for high-temperature duty, while 1.4541 is the usual choice lower down. Related stabilised grades: A182-F321 and AISI 347H.
2. Chemical composition
| Grade | C | Si | Mn | P | S | Cr | Ni | Ti |
|---|---|---|---|---|---|---|---|---|
| X12CrNiTi18-9 / X8CrNiTi18-10 (1.4878) | ≤0.10 | ≤1.0 | ≤2.0 | ≤0.045 | ≤0.015 | 17.0-19.0 | 9.0-12.0 | 5×C to 0.8 |
| AISI 321H (UNS S32109) | 0.04-0.10 | ≤0.75 | ≤2.0 | ≤0.045 | ≤0.030 | 17.0-19.0 | 9.0-12.0 | 0.16-0.70 |
| AISI 321 (UNS S32100), for comparison | ≤0.08 | ≤0.75 | ≤2.0 | ≤0.045 | ≤0.030 | 17.0-19.0 | 9.0-12.0 | ≤0.7 |
Balance iron. Heat analysis appears on every certificate. Product analysis can be added if you state it at enquiry stage.
Function of the titanium addition
Titanium fixes carbon as titanium carbides, so chromium carbides do not precipitate at the grain boundaries. Chromium stays in solution. This is what gives the grade its resistance to intergranular corrosion, including after welding and after long spells at temperature.
3. Mechanical and physical properties
| Property | Value |
|---|---|
| Tensile strength, Rm | 500-720 N/mm² (72-104 ksi) |
| Yield strength, Rp0.2 | ≥190 N/mm² (≥27.5 ksi) |
| Elongation, A | ≥40 % |
| Hardness | ≤215 HB |
| Modulus of elasticity, E | approx. 200 GPa |
| Density | 7.9 kg/dm³ |
| Thermal conductivity at 20 °C | 15 W/m·K |
| Specific heat capacity | 500 J/kg·K |
| Electrical resistivity | 0.73 Ω·mm²/m |
| Magnetic behaviour | Low, slightly magnetic |
Creep data at elevated temperature
| Property | 600 °C | 700 °C | 800 °C |
|---|---|---|---|
| Creep limit R1/1000 | 110 | 45 | 15 |
| Creep limit R1/10000 | 85 | 30 | 10 |
| Creep rupture Rz/1000 | 200 | 88 | 30 |
| Creep rupture Rz/10000 | 142 | 48 | 15 |
| Creep rupture Rz/100000 | 65 | 22 | 10 |
These are published reference figures for the grade, not design allowables. Use them for pre-selection and confirm against the code governing your equipment.
4. Heat treatment
Delivery condition is solution annealed: 1020 to 1120 °C, cooled in water or air, the medium chosen by section thickness and distortion risk.
Caution. This grade is not precipitation hardening. There is no ageing step and no solution-plus-age cycle for 1.4878. Strength comes from the solid solution and the worked structure. If an enquiry specifies ageing for this material, it should be queried before order confirmation. For an age-hardenable stainless steel see 17-4PH, 15-5PH or PH13-8Mo.
5. Corrosion and high-temperature behaviour
Suitable conditions
Scaling resistance in air runs to about 850 °C, and behaviour in oxidising atmospheres is good. Resistance to intergranular attack is high both solution annealed and as welded, which is why the grade is relied on for welded assemblies carrying combined thermal and pressure loading. General corrosion resistance is good in natural, low-chloride environments.
Unsuitable conditions
Service limits. The grade is not seawater resistant and is liable to pitting and crevice attack in chloride-rich media. For those duties use molybdenum-alloyed grades such as 1.4404, 904L, A182-F44 or A182-F51. It is also not suited to carburising or sulfur-rich atmospheres, and in strongly acidic or chloride-laden media it is conditionally resistant at best. Hydrofluoric acid, strong alkali and wet chlorine duties call for nickel alloys such as Hastelloy C-276, Monel 400 or Inconel 625.
6. Fabrication and weldability
The grade welds by all conventional processes, with or without filler, and post-weld heat treatment is not required. Titanium lowers the risk of hot cracking. Like every austenitic stainless steel it work-hardens during cold forming and machining, so machining wants positive rake tooling, a rigid setup, steady feed and plenty of coolant to keep the cut from glazing.
7. Forged product forms in this grade
We are an open-die forging plant, so size is set by your drawing rather than by a stock list. Usual forms in 1.4878 are seamless rolled rings and forged rings, forged flanges and discs, shafts and spindles, forged round bars, sleeves and bushings, forged tubes and tube sheets, hollow bars, and forged blocks and bodies for valve work. Ring rolling, upsetting, open-die drawing and saddle forging are all in house, with rough or finish machining to print on request.
8. Typical applications
Creep strength, scaling resistance to 850 °C and the stabilised structure put this grade mainly into hot service. Published application areas for 1.4878 cover equipment and pressure vessel construction, chemical and petrochemical plant, nuclear technology, pulp and paper, food processing, and automotive and building work. In forged form that usually means heat exchanger components and tube sheets, high-temperature piping parts and flanges, furnace internals and retort parts, expansion and exhaust components, burner parts, and rings and shafts in hot-gas equipment. For pipe and tube the standards usually quoted are EN 10216-5, EN 10297-2 and ASME SA312.
9. Testing, inspection and certification
Being austenitic, these forgings are ultrasonically examined to EN 10228-4, the part of the EN 10228 series written for austenitic and austenitic-ferritic stainless steel forgings. EN 10228-3 covers ferritic and martensitic forgings only and is the wrong reference for this grade. ASTM A388 is available where a US specification is preferred. Certificates are issued to EN 10204 3.1, or EN 10204 3.2 with third-party witnessing by SGS, BV, TUV, Lloyd's or an inspector you nominate. Dimensional reports, mechanical test reports, PMI, intergranular corrosion testing and liquid penetrant examination can be written into the inspection and test plan.
10. Common questions
What is X12CrNiTi18-9 equivalent to?
Werkstoff 1.4878, written X8CrNiTi18-10 in EN 10095. ASTM equivalent is AISI 321H / UNS S32109 (TP321H). Other national names include 1H18N9T and 12Ch18N10T.
What is the maximum service temperature?
Scaling resistant in air to roughly 850 °C. Allowable stress at temperature must come from the design code. The creep table in section 3 is for pre-selection.
Is X12CrNiTi18-9 the same as 321?
Not quite. 321 (1.4541) carries lower carbon. 321H / 1.4878 carries higher carbon and therefore higher creep strength, which is why it is the one specified hot. Material is often dual certified where both sets of limits are met.
Can you forge to drawing and machine the part?
Yes. Send the drawing or rough dimensions, quantity, governing standard and inspection level to sales@steelforgepieces.com and we will price the forging and any machining together.
What do you need for a quotation?
Grade and standard, finished or rough dimensions (OD / ID / height, or length and diameter), quantity, delivery condition, UT and certificate requirements, destination port.
Request a quotation
Send your drawing or sizes and we will come back with price, weight and lead time.
Email sales@steelforgepieces.com Call 0086-189-2135-9659
Supplier: Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. Telephone 0086-189-2135-9659, email sales@steelforgepieces.com. Property data shown here is reference information and is non-binding. Confirm all design values against the standard governing your application.