Summary
1.4878 (X8CrNiTi18-10) is a titanium-stabilised austenitic heat-resisting stainless steel to EN 10095, equivalent to AISI 321H and UNS S32109. Titanium ties up carbon as titanium carbide, keeping chromium available at the grain boundaries, which is what gives the steel its resistance to intergranular corrosion after welding or long heating. It is scaling resistant in air to about 850 °C and is used against hot gases and combustion products above 550 °C.
Jiangyin Jiangnan Metal Co., Ltd. forges 1.4878 into seamless rolled rings, flanges, shafts, discs, sleeves, bushings, tube sheets and round bars to customer drawings.
- EN number
- 1.4878
- EN designation
- X8CrNiTi18-10
- Former DIN
- X12CrNiTi18-9
- AISI / SAE
- 321H
- UNS
- S32109
- Standard
- EN 10095
- Structure
- Austenitic, not hardenable
- Scaling resistance
- approx. 850 °C in air
- Delivery condition
- Solution annealed
- Density
- 7.9 g/cm³
Chemical composition
1.4878 is stabilised with titanium, not niobium. The EN and ASTM limits differ on sulphur and titanium, so state which one governs your order.
| Element | EN 1.4878 (X8CrNiTi18-10) | ASTM 321H (UNS S32109) |
|---|---|---|
| C | 0.04 – 0.10 | 0.04 – 0.10 |
| Si | max 1.00 | max 0.75 |
| Mn | max 2.00 | max 2.00 |
| P | max 0.045 | max 0.045 |
| S | max 0.015 | max 0.030 |
| Cr | 17.0 – 19.0 | 17.0 – 19.0 |
| Ni | 9.0 – 12.0 | 9.0 – 12.0 |
| Ti | min 5 × C, max 0.80 | 0.16 – 0.70 |
| Fe | Balance | Balance |
Heat analysis is reported on the EN 10204 3.1 certificate issued with every order. A 3.2 certificate countersigned by TUV, BV, SGS or LRS is available on request.
Mechanical properties at 20 °C
| Property | Value |
|---|---|
| Tensile strength Rm | 500 – 720 N/mm² |
| 0.2 % proof strength Rp0.2 | min 190 N/mm² |
| Elongation A5 | min 40 % |
| Hardness | max 215 HB 30 |
| Modulus of elasticity | approx. 200 kN/mm² |
Published datasheets quote tensile strength as either 500–720 or 550–700 N/mm² depending on product form and section size. Acceptance values for a given forging are agreed at order stage and confirmed by test on the delivered material.
As an H grade, 1.4878 is chosen over 1.4541 where creep strength under sustained temperature matters, which is why it appears in pressure parts, heat exchangers and high-temperature piping. Creep figures are not published here: work from the values in EN 10095 or from your own specification, and we will test to it.
Physical properties at 20 °C
| Property | Value |
|---|---|
| Density | 7.9 g/cm³ |
| Specific heat capacity | 500 J/(kg·K) |
| Thermal conductivity | 15 W/(m·K) |
| Electrical resistivity | 0.73 Ω·mm²/m |
| Mean expansion, 20–200 °C | 17.0 × 10-6 K-1 |
| Magnetic response | Low; rises with cold work |
Heat treatment
1.4878 is austenitic and cannot be hardened by heat treatment. There is no quench and temper cycle and no solution and age cycle for this grade. Forgings are supplied solution annealed at 1020–1120 °C and rapidly cooled in water or air. Any strength above the annealed minimum comes from cold work, which also increases magnetic response. Confirm the annealing temperature against the standard governing your order.
Where 1.4878 works and where it does not
Suitable for
Oxidising atmospheres, hot gases and combustion products above 550 °C, with scaling resistance in air to about 850 °C. Welded assemblies that must stay free of intergranular attack. Loaded parts held at temperature for long periods.
Not suitable for
Seawater and chloride-rich media, where it pits and suffers crevice corrosion. Resistance to carburising gases is only moderate, and resistance to oxidising and reducing sulphurous gases is low.
If your atmosphere is sulphur bearing or strongly carburising, or the service is chloride wet, ask us to quote Incoloy 800H, Incoloy 800HT or Haynes 230 instead. We forge those grades as well.
1.4878 compared with 1.4541
Both are titanium-stabilised austenitic steels and they are often dual certified. 1.4878 carries the higher carbon, which raises creep strength and makes it the grade for high-temperature duty. 1.4541 is the usual choice for lower-temperature and wet corrosion service. If your part runs hot under load for thousands of hours, specify 1.4878; otherwise A182 F321 / 1.4541 is normally cheaper and adequate.
Equivalent designations
X8CrNiTi18-10, X12CrNiTi18-9, X7CrNiTi18-10, AISI 321H, TP321H, UNS S32109, 12Ch18N10T and 12X18H10T (GOST), 1H18N9T (PN), Z6CNT18-10 (NF).
Cross-references are a guide only. Carbon, sulphur and titanium limits differ between the EN and ASTM versions, so confirm the governing specification and acceptance criteria before ordering.
Forged products in 1.4878
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory. In 1.4878 we produce seamless rolled rings, forged flanges and flange blanks, round bars and billets, shafts and spindles, discs, sleeves and bushings, tube sheets, hollow bars and tube blanks, valve bodies, valve seat rings and valve stems, nozzles, gear blanks and roll blanks, all to customer drawing.
Typical applications
Furnace and apparatus engineering, including annealing furnaces, muffle furnaces and hardening boxes; exhaust and hot gas components; pressure equipment and piping; heat exchanger parts; and process equipment in the chemical, petrochemical, pulp and paper and food sectors.
Process route, testing and certification
Melting by EAF with AOD or VOD refining, with ESR remelting where the specification or section size calls for it. Forgings are solution annealed, then machined to your tolerance.
Ultrasonic examination is to EN 10228-4, the part covering austenitic and austenitic-ferritic stainless steel forgings; EN 10228-3 applies to ferritic and martensitic forgings and is not the correct reference for 1.4878. ASTM A388 is applied where specified. Forgings for pressure purposes can be supplied to EN 10222-5, and flanges and forged fittings for high-temperature service to ASTM A182 F321H. Certification is to EN 10204 3.1 or 3.2.
Machining and welding
1.4878 work hardens quickly. Use sharp tooling with positive rake, rigid setups, heavy constant feed and plenty of coolant, and do not let the tool dwell.
All common welding processes can be used, with or without filler. Preheat is not required, interpass temperature should stay below 150 °C, and post-weld heat treatment is not normally needed. Because austenitic steel has roughly 30 percent of the thermal conductivity of unalloyed steel and a much higher expansion coefficient, expect more distortion: weld with lower heat input, stringer beads, back-step sequences and closely spaced tacks, and prefer a double-V preparation above 12 mm thickness. Suitable filler materials are 1.4551 and 1.4829. Delta ferrite in the weld metal up to about 10 percent reduces hot-cracking sensitivity without generally harming corrosion resistance. Afterwards remove heat tint, scale, slag and spatter by brushing, grinding, pickling or iron-free blasting, use only stainless brushes and tools, and rinse thoroughly after pickling so the passive layer reforms.
Frequently asked questions
What is 1.4878 steel?
A titanium-stabilised austenitic heat-resisting stainless steel under EN 10095, equivalent to AISI 321H and UNS S32109, scaling resistant in air to about 850 °C.
Is 1.4878 the same as 321H?
Yes. 1.4878 is the EN material number for AISI 321H, UNS S32109, EN designation X8CrNiTi18-10.
What is the difference between 1.4541 and 1.4878?
1.4878 carries higher carbon, which raises creep strength for high-temperature service. 1.4541 suits lower-temperature and wet corrosion duty. The two are often dual certified.
What is the maximum service temperature?
About 850 °C for scaling resistance in air. The practical limit is lower in carburising or sulphur-bearing atmospheres.
Can 1.4878 be hardened by heat treatment?
No. It is austenitic and non-hardenable, supplied solution annealed and rapidly cooled.
Is 1.4878 resistant to seawater?
No. It pits and suffers crevice corrosion in chloride-rich media. Use a molybdenum-bearing grade for seawater.
Which ultrasonic standard applies?
EN 10228-4 for austenitic and austenitic-ferritic stainless forgings. EN 10228-3 does not apply.
Request a quotation for 1.4878 forgings
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China, producing forged rings, seamless rolled rings, flanges, shafts, discs, bushings and bars in stainless steel, nickel alloy, tool steel, alloy steel and carbon steel, including 1.4878 / X8CrNiTi18-10 / AISI 321H.
No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, ChinaPhone, WhatsApp and WeChat: +86 189-2135-9659
Email: sales@steelforgepieces.com Send your drawing
Data on this page follows published datasheets for EN 1.4878 / X8CrNiTi18-10 / AISI 321H and is given for orientation. It does not replace the governing standard or an agreed purchase specification, and it is not a guarantee of results in processing or service.