01Chemical composition of 1.4845
The EN limits and the ASTM 310S limits are not the same. EN allows more carbon, sets a nitrogen limit and holds sulphur tighter. State which specification governs your order, because it changes the mill certificate.
| 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 |
Molybdenum, copper and titanium are not alloyed in this grade.
02Mechanical properties at 20 °C
Values apply to the solution-annealed condition, +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.
03Physical data
| EN material number | 1.4845 |
|---|---|
| EN designation | X15CrNi25-21; also published as X8CrNi25-21 and X12CrNi25-21 |
| Structure | Austenitic heat-resisting stainless steel, non-magnetic |
| Nominal alloy | 25% Cr / 20% Ni |
| 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 |
| Maximum temperature in air | about 1050 °C |
041.4845 at elevated temperature
These values are the reason the grade is chosen over 304 or 309 for sustained heat.
| 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 |
| Temperature | 1 000 h | 10 000 h |
|---|---|---|
| 600 °C | 100 | 90 |
| 700 °C | 45 | 30 |
| 800 °C | 18 | 10 |
| 900 °C | 10 | 4 |
| 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.
05Forging and heat treatment
| Hot forming | 1150-800 °C, slow cooling in air |
|---|---|
| Solution annealing, +AT | 1050-1150 °C, quench in air or water |
| Ageing or precipitation hardening | Not applicable. The grade is austenitic and does not harden by heat treatment. Strength is raised only by cold work |
| Machining | Similar to 304, less machinable than 410. High work-hardening rate, so use rigid setups, positive rake and steady feed |
| Welding | Arc, TIG, MAG and laser welding are suitable. Gas welding should not be used. 1.4842 (X12CrNi25-20) is a suitable filler. Control carbide precipitation and hot cracking |
| Cold forming | Possible; the grade suits both forging and cold forming |
06Equivalent grades and standards
| 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 and 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 (heat-resisting steels), EN 10088-3 (composition) |
071.4845 forged products
All forms are made to customer drawing. Send the drawing or rough dimensions and we will confirm what we can hold in this grade.
- Forged rings and seamless rolled ringsKilns, heat exchangers, radiant tube assemblies, muffles, retorts, annealing covers.
- Forged flanges and tube sheetsPressure vessels, air receivers, shell-and-tube heat exchangers.
- Forged shafts and spindlesFurnace drives, power transmission, compressors, gearboxes.
- Forged discs, sleeves, bushings and rollsSaggers, furnace internals, conveyor rollers, oven linings, fans.
- Forged round bars and blocksMachined furnace and valve components.
- Forged pipe, tubes and nozzlesHigh-temperature process piping and vessel nozzles.
- Forged valve partsBodies, stems, seat rings and blocks for ball, gate, globe, check and plug valves.
08Where 1.4845 forgings are used
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.
09Manufacturing, testing and certification
Jiangyin Jiangnan Metal melts 1.4845 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.
101.4845 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 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.
11Data sources
Composition, room-temperature and elevated-temperature values on this page 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. Figures are for orientation and are non-binding. The governing document is the specification stated on the purchase order.