# 1.4845 Forgings (AISI 310S / X15CrNi25-21)

1.4845 is a heat-resisting austenitic stainless steel with 24.0-26.0% chromium and 19.0-22.0% nickel, equivalent to AISI 310S and UNS S31008, scale-resistant in air up to about 1050 °C. Jiangyin Jiangnan Metal Co., Ltd. forges this grade in Jiangyin, Jiangsu, China, as rings, seamless rolled rings, flanges, shafts, discs, sleeves, bushings, tube sheets, bars and forged pipe, to drawing, with EN 10204 3.1 or 3.2 certification.

- Source page: https://www.steelforgepieces.com/Stainless-Steel/1.4845.html
- Manufacturer: Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China
- Data reviewed: 26 September 2026

## Summary data

| Item | Value |
| --- | --- |
| EN material number | 1.4845 |
| EN designation | X15CrNi25-21; also published as X8CrNi25-21 and X12CrNi25-21 |
| AISI / SAE | 310S |
| UNS | S31008 |
| Structure | Austenitic heat-resisting stainless steel, non-magnetic |
| Nominal alloy | 25% Cr / 20% Ni |
| Maximum temperature in air | about 1050 °C |
| Density at 20 °C | 7.9 kg/dm³ |
| Melting point | about 1455 °C |
| Thermal conductivity | 15 W/m·K |
| Modulus of elasticity | 196 kN/mm² |
| Electrical resistivity | 0.85 Ω·mm²/m |
| Heat treatment | Solution annealing only, 1050-1150 °C; not hardenable |
| Ultrasonic testing | EN 10228-4; ASTM A388 on request |

## Chemical composition (mass %, max unless a range is shown)

| Specification | C | Si | Mn | P | S | N | Cr | Ni |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| EN 1.4845 (EN 10088-3) | 0.10 | 1.50 | 2.00 | 0.045 | 0.015 | 0.11 | 24.0-26.0 | 19.0-22.0 |
| ASTM 310S (UNS S31008) | 0.08 | 1.50 | 2.00 | 0.045 | 0.030 | not specified | 24.0-26.0 | 19.0-22.0 |

The EN and ASTM limits are not identical. EN allows more carbon, sets a nitrogen limit and holds sulphur tighter. State which specification governs the order, because it changes the mill certificate. Molybdenum, copper and titanium are not alloyed in this grade.

## Mechanical properties at 20 °C, solution annealed (+AT)

| Property | EN 10095 | ASTM 310S |
| --- | --- | --- |
| Tensile strength Rm | 500-750 N/mm² | 515 MPa min |
| Yield strength Rp0.2 | ≥ 210 N/mm² | 205 MPa min |
| Elongation A5 | ≥ 35% | 40% min in 50 mm |
| Hardness | ≤ 192 HB | 95 HRB max |
| Modulus of elasticity | 196 kN/mm² | 196 kN/mm² |

Some mill datasheets quote Rm as 550-750 N/mm² for the same grade. Where the difference affects design, work to the value in the specification named on the order.

## Creep rupture strength (N/mm²)

| Temperature | 1 000 h | 10 000 h | 100 000 h |
| --- | --- | --- | --- |
| 600 °C | 170 | 130 | 80 |
| 700 °C | 80 | 40 | 18 |
| 800 °C | 35 | 18 | 7 |
| 900 °C | 15 | 8.5 | 3 |

## 1% creep limit (N/mm²)

| Temperature | 1 000 h | 10 000 h |
| --- | --- | --- |
| 600 °C | 100 | 90 |
| 700 °C | 45 | 30 |
| 800 °C | 18 | 10 |
| 900 °C | 10 | 4 |

## Mean coefficient of thermal expansion (10⁻⁶ K⁻¹)

| 200 °C | 400 °C | 600 °C | 800 °C | 1000 °C |
| --- | --- | --- | --- | --- |
| 15.5 | 17.0 | 17.5 | 18.5 | 19.0 |

## Atmosphere limits

In oxidising atmospheres 1.4845 stays scale-resistant and dimensionally stable. Resistance is limited in reducing, sulphur-bearing and carburising conditions, and another alloy should be chosen for those services. In the as-welded condition the grade is not resistant to intergranular corrosion.

## Forging and heat treatment

| Operation | Parameters |
| --- | --- |
| Hot forming | 1150-800 °C, slow cooling in air |
| Solution annealing (+AT) | 1050-1150 °C, quench in air or water |
| Ageing / precipitation hardening | Not applicable; austenitic grade, strength raised only by cold work |
| Machining | Similar to 304, less machinable than 410; high work-hardening rate |
| Welding | Arc, TIG, MAG and laser suitable; no gas welding; filler 1.4842 (X12CrNi25-20) |
| Cold forming | Possible; the grade suits both forging and cold forming |

## Equivalents and standards

| System | Designation |
| --- | --- |
| EN / DIN | 1.4845, X15CrNi25-21 |
| AISI / SAE | 310S |
| UNS | S31008 |
| BS | 310S16, 310S24, 310S31 |
| JIS | SUS310 |
| GB | 1Cr25Ni20Si2 |
| AFNOR | Z12CN25-20 |
| UNI | X6CrNi25-20 |
| SS | 2361 |
| PN | H23N18 |
| Forged flanges and fittings | ASTM A182 F310, ASTM A182 F310S |
| Plate, sheet, bar | ASTM A240, ASTM A276, AMS 5521, AMS 5651 |
| Seamless pipe | EN 10216-5, EN 10297-2, SEW 470, ASME SA312 |
| Base standards | EN 10095, EN 10088-3 |

## Forged products in 1.4845

All forms are made to customer drawing.

- Forged rings and seamless rolled rings: kilns, heat exchangers, radiant tube assemblies, muffles, retorts, annealing covers
- Forged flanges and tube sheets: pressure vessels, air receivers, shell-and-tube heat exchangers
- Forged shafts and spindles: furnace drives, power transmission, compressors, gearboxes
- Forged discs, sleeves, bushings and rolls: saggers, furnace internals, conveyor rollers, oven linings, fans
- Forged round bars and blocks: machined furnace and valve components
- Forged pipe, tubes and nozzles: high-temperature process piping, vessel nozzles
- Forged valve parts: bodies, stems, seat rings, blocks for ball, gate, globe, check and plug valves

## Applications

Because the grade holds oxidation resistance and useful strength close to 1050 °C, it is specified for industrial furnace and kiln components, furnace tubes and exhaust systems, high-temperature reactors, heat exchanger internals, chemical and petrochemical plant parts exposed to heat, machine parts running hot, and pressure vessels and pipelines in heated service.

## Manufacturing, testing and certification

Melting is by EAF and VOD, with ESR remelting where the order calls for it. Ring dimensions, wall, height and single-piece weight are quoted against the drawing.

Forgings are ultrasonically tested to EN 10228-4, the part of that standard covering austenitic and austenitic-ferritic stainless steel forgings. EN 10228-3 is not quoted for this grade, because its scope covers ferritic and martensitic forgings only. ASTM A388 is used where a customer specification requires it.

Certificates are issued to EN 10204 type 3.1, the manufacturer's inspection certificate with actual test results, or type 3.2, which is additionally countersigned by an independent third party or by the buyer's nominated inspector.

## Questions and answers

**What is 1.4845 steel?** A heat-resisting austenitic stainless steel with 24.0-26.0% chromium and 19.0-22.0% nickel, the EN material number for AISI 310S and UNS S31008, usable in air to about 1050 °C.

**Is 1.4845 the same as 310S?** They are treated as equivalent in trade, but the chemistry limits differ. EN allows up to 0.10% carbon and sets nitrogen at 0.11% maximum, while ASTM 310S caps carbon at 0.08% and does not specify nitrogen.

**Can 1.4845 forgings be hardened?** No. The grade is austenitic and does not respond to hardening heat treatment. Solution annealing at 1050-1150 °C is the only treatment applied, and hardness rises only through cold work.

**Is 1.4845 magnetic?** No. It stays non-magnetic and keeps low magnetic permeability even after cold working.

**What is the maximum service temperature?** About 1050 °C in air. For higher temperatures 1.4841 is the usual choice. Service life falls in sulphur-bearing, reducing or carburising atmospheres.

**How does 1.4845 compare with 1.4841?** 1.4845 carries less carbon, which improves scaling resistance. 1.4841 is selected when oxidation resistance has to hold above the 1.4845 limit.

**Which ultrasonic standard applies?** EN 10228-4.

**Which standards should be quoted on an order?** ASTM A182 F310 or F310S for forged flanges and fittings, ASTM A240 or A276 for plate and bar, EN 10095 and EN 10088-3 for the European grade, and EN 10228-4 for ultrasonic acceptance.

**How do I get a price?** Send the drawing or rough dimensions with quantity, governing specification, heat-treatment condition, NDT level and certificate type.

## Data sources

Composition, room-temperature and elevated-temperature values are cross-checked against published datasheets for 1.4845 and AISI 310S issued to EN 10095 and EN 10088-3, against ASTM 310S (UNS S31008) composition and mechanical minima, and against the scope statements of EN 10228-3, EN 10228-4 and EN 10204.

## Supplier

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

Figures are for orientation and non-binding. The governing document is the purchase order specification.