Furnace plant
Furnace components, hood annealing and muffle furnaces, lifting bar furnaces, heat treatment furnace tubes, charging cages, insert boxes, sealing sheets.
01
What this grade is
X9CrNiSiNCe21-11-2 is the EN name for heat resisting austenitic stainless steel 1.4835, standardised in DIN EN 10095:2018-12 and equivalent to UNS S30815. It holds 20.0–22.0 % chromium, 10.0–12.0 % nickel and 1.40–2.50 % silicon, with 0.12–0.20 % nitrogen and 0.03–0.08 % cerium.
The base alloy is close to 1.4828 (AISI 309). What changes the behaviour is the higher nitrogen and the rare earth cerium. Nitrogen raises strength and creep resistance; cerium keeps the Cr2O3 scale bonded to the metal when the temperature swings quickly. The grade is used above 550 °C against hot gases and products of combustion, with a highest application temperature in air of 1150 °C and warranted scaling resistance under wide and fast thermal fluctuation. It has no resistance in a reducing atmosphere.
Jiangyin Jiangnan Metal Co., Ltd. melts and forges this grade at one site in Jiangyin City, Jiangsu Province, China. Output covers seamless rolled rings to 6000 mm outside diameter, forged rings, flanges, discs, tube sheets, shafts, sleeves, bushings and bars, up to 30 tonnes per piece.
02
Chemical composition
Two sets of limits circulate for this material and they are not identical. Check which one your purchase order calls for before enquiry, because the silicon, manganese and nitrogen windows differ.
| Specification | C | Si | Mn | P | S | Cr | Ni | N | Ce |
|---|---|---|---|---|---|---|---|---|---|
| EN 1.4835 | 0.05–0.12 | 1.40–2.50 | < 1.00 | < 0.045 | < 0.015 | 20.00–22.00 | 10.00–12.00 | 0.12–0.20 | 0.030–0.080 |
| UNS S30815 | 0.05–0.10 | 1.40–2.00 | < 0.80 | < 0.040 | < 0.030 | 20.00–22.00 | 10.00–12.00 | 0.14–0.20 | 0.030–0.080 |
| ISO X7CrNiSiNCe21-11 | 0.05–0.10 | 1.40–2.00 | < 0.80 | < 0.040 | < 0.030 | 20.00–22.00 | 10.00–12.00 | 0.14–0.20 | 0.030–0.080 |
Balance iron. Molybdenum, titanium, niobium, vanadium, tungsten and aluminium are not specified alloying elements. One proprietary version of the grade permits Mo below 0.54 %. Every heat we forge ships with its ladle analysis on the certificate.
Why the cerium is there
Rare earth cerium is what distinguishes 1.4835 from 1.4828. It improves adhesion of the chromium oxide scale, so the layer resists spalling when equipment is heated and cooled repeatedly. That is the normal failure mode in batch furnaces and cyclically fired plant, and it is the reason this grade is specified over a cheaper CrNiSi steel.
03
Mechanical properties
Values apply at 20 °C in the annealed +AT condition, which is how we deliver forgings in this grade unless a purchase order says otherwise.
| Property | Symbol | Value | Imperial |
|---|---|---|---|
| Tensile strength | Rm | 650 – 850 MPa | 94 – 123 ksi |
| Proof stress 0.2 % | Rp0.2 | 310 MPa | 45 ksi |
| Elongation | A | > 37 % | > 37 % |
| Elongation, longitudinal | A5 | > 40 % | > 40 % |
| Brinell hardness | HB 30 | < 210 HB | < 210 HB |
| Modulus of elasticity | E | 200 kN/mm² | 29 000 ksi |
Check the yield figure on your enquiry
Some trade listings for this grade quote a minimum yield of 345 MPa (50 ksi). The EN 10095 figure is 310 MPa, and tensile strength is a band of 650–850 MPa rather than an open minimum. We can forge and test to a tighter contractual yield, but it has to be agreed on the order and proved on the certificate. It is not a property the grade carries automatically.
04
Physical properties
| Property | Symbol | Value |
|---|---|---|
| Density | ρ | 7.80 kg/dm³ |
| Specific heat capacity, 20–100 °C | cp | 500 J·kg-1·K-1 |
| Thermal conductivity | λ | 15 W·m-1·K-1 |
| Electrical resistivity | ρel | 0.85 Ω·mm²/m |
| Linear expansion, 20–100 °C | α | 17.0 – 19.5 × 10-6 K-1 |
| Magnetisability | — | None, annealed condition |
Expansion is high, as it is for all austenitic steels. Allow for it in furnace fixtures and in any joint between this grade and a ferritic component.
05
Creep data
These are the figures that govern design of load-bearing parts in this grade. The headline 1150 °C figure describes scaling behaviour, not load capacity.
| Property | 600 °C | 700 °C | 800 °C | 900 °C | 1000 °C |
|---|---|---|---|---|---|
| Rz/1000 | 238 | 105 | 50 | 24 | 12 |
| Rz/10000 | 157 | 63 | 27 | 13 | 7 |
| Rz/100000 | 88 | 35 | 15 | 8 | 4 |
| R1/1000 | 170 | 66 | 31 | 15.5 | 8 |
| R1/10000 | 126 | 45 | 19 | 10 | 5 |
| R1/100000 | 80 | 26 | 11 | 6 | 3 |
Rz is creep rupture strength, R1 is the 1 % creep limit, subscripts are hours. Reference values for guidance. They do not replace a code calculation or the sign-off of a design authority.
06
Equivalent designations
| System | Designation | Standard |
|---|---|---|
| EN material number | 1.4835 | DIN EN 10095:2018-12 |
| EN name | X9CrNiSiNCe21-11-2 | EN 10095, EN 10088-1 |
| International | X7CrNiSiNCe21-11 | ISO 4955 |
| USA | UNS S30815 | ASTM A240, ASTM A479 |
| USA, common name | 253MA | SAE / ASTM UNS listing |
| Further listing | X10CrNiSiN21-11 | Stahlschlüssel |
| Related EN grade | 1.4893, X8CrNiSiN21-11 | Nitrogen without cerium |
| Predecessor standard | 1.4835 | DIN EN 10095:1999-05, superseded |
Mill trade names recorded for this grade include Therma 253 MA (Outokumpu), Avesta 253 MA, RA 253 MA, BGH 4835 (BGH Edelstahl Siegen) and Permodur 4835 (Deutsche Edelstahlwerke). Those names and the 253 MA mark belong to their respective owners. Jiangyin Jiangnan Metal has no affiliation with them and supplies forgings made to the EN 1.4835 or UNS S30815 specification. The names appear here only so buyers can match a drawing callout.
07
Heat treatment
| Process | Temperature | Time | Cooling |
|---|---|---|---|
| Softening / solution annealing | 1020 – 1120 °C | 5 – 20 min | Fast, in air or water |
| Stress relief annealing | 850 – 950 °C | < 30 min | Fast, in air |
| Thermo-mechanical treatment | 900 – 1150 °C | — | Air |
A frequent specification error
Stress relief at 850–950 °C is not the delivery heat treatment for this grade and will not restore a solution annealed structure after forging. Forgings must be annealed at 1020–1120 °C and cooled fast. Orders that list only the stress relief cycle are a common cause of certificate disputes at inspection, so we query them before production starts.
Both cycles run in our own furnaces. Solution annealing at this temperature is handled in the high-temperature car-bottom furnaces, and long shafts are treated vertically in the 15 m deep well furnaces to keep them straight through the quench.
08
Forging, welding, machining
Hot working
Thermo-mechanical treatment runs between 900 and 1150 °C. The nitrogen addition makes this steel noticeably stiffer to deform than 304 or 309, so press force, reheat scheduling and bite size all have to account for it. An under-powered press produces centre cracking rather than a sound forging. Hot bending is carried out at 850–1100 °C. Plasticity is much better than that of ferritic steels.
Cold forming
Cold working is straightforward, but the nitrogen content means more force is needed than for a conventional austenitic grade, and the steel springs back, so compensation is required. Parts that will later run above 800 °C should be annealed after cold bending.
Welding
Welded by coated electrode arc, pure argon, plasma and MIG. TIG and MIG give the best creep resistance at high temperature. A suitable filler is 1.4842. No preheat or post-weld heat treatment is normally needed. Expect a local magnetic response around the weld.
Machining
Sulphur is held below 0.015 % in the EN version, so this is not a free-machining steel, and it work-hardens quickly. Use sharp rigid tooling, positive rake, reduced surface speed and a heavy uninterrupted feed. Dwelling in the cut glazes the surface and ruins tool life. We can supply rough-machined or finish-machined forgings from our own vertical lathes and CNC machines if you would rather not run it in-house.
09
Forged range in this grade
| Product | Size limit | Set by |
|---|---|---|
| Seamless rolled rings | OD 50 – 6000 mm | 6 m radial-axial ring mill; upset and punch below mill range |
| Forged rings, retaining rings, seat rings | to OD 6000 mm | 6300 t press |
| Forged flanges | to OD 6000 mm | Press and ring mill |
| Discs, tube sheets, covers | to 5000 mm machined dia | 5000 mm vertical lathe |
| Shafts, spindles, eccentric shafts | to 14 000 mm turned length | C61160 lathe; 15 m well furnace |
| Sleeves, bushings, hollow cylinders | to 1600 mm dia × 10 000 mm | CNC deep-hole drilling machine |
| Round bars, blocks | per drawing | Press and hammers |
| Nozzles, manifolds, valve bodies and bonnets | per drawing | Press and machine shop |
| Single piece weight | to 30 000 kg | 60 t heat size, 6300 t press |
Minimum order is 10 kg with no minimum piece count, so one-off prototypes are accepted. Open-die forging needs no dies, which is what keeps single pieces economic. Normal lead time is 20 to 60 days.
10
Where it is used
Documented applications for 1.4835 centre on equipment that runs hot and cycles often.
Heat recovery
Recuperators, radiator and radiant tubes, air heating tubes in sulphuric acid gas converters, high-temperature heat exchangers.
Combustion
Combustion nozzles, burner components, and heavily loaded parts of waste gas detoxification plant.
Petrochemical
Styrene reactors, convection tubes, and reactor internals running above 550 °C.
Steel, glass, cement
Hot-zone hardware in steelworks, glass and cement plant, where thermal cycling is continuous.
Measurement
Thermocouple tubes and protection sheaths for high-temperature process measurement.
11
Service limits
Putting this grade in the wrong duty is an expensive mistake, so the restrictions are set out here rather than buried. 1.4835 resists heat. It is not a general corrosion resisting steel.
| Condition | Behaviour of 1.4835 | Consider instead |
|---|---|---|
| Contact with water | Not rated. Corrosion resistance is reduced against standard austenitic steels and is not given in combination with water. | 316L, 1.4462 duplex, 904L |
| Reducing atmosphere | No resistance. | Nickel alloys selected for the atmosphere |
| Oxidising sulphuric gases | Low resistance. | Alloy 600 and 601 family |
| Chloride, seawater, subsea | Not suitable. | A182-F53, A182-F55, A182-F44 |
| Below 550 °C in service | Outside the intended range. Nothing is gained over a cheaper grade. | Standard austenitic or alloy steel |
| Sustained load near 1150 °C | Scaling limit, not a load limit. Creep strength at 1000 °C is already in single-figure MPa. | Alloy 602, Haynes 230, Inconel 601 |
One further point worth raising before you order. At least one supplier datasheet for 1.4835 states that the grade should not be used for forging. Other published datasheets list forged and cast parts as a normal delivery form and give a hot working range of 900–1150 °C, which is the position we work to. If your inspector raises the objection, ask us and we will set out the forging and annealing route we propose for your part before any steel is melted.
12
How we make it
Most forging suppliers in China buy billet. This works starts at the furnace. Steel is melted and refined on site, forged or ring-rolled, heat treated, machined and tested without leaving the plant, so the certificate traces a part back to its melt number instead of stopping at a purchased billet. For a nitrogen-alloyed grade that matters, because nitrogen has to be held inside a narrow band and it is controlled in the melt shop, not afterwards.
| Item | Detail |
|---|---|
| Established | 1997, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China |
| People | 460, including 9 senior engineers, 32 intermediate engineers and 140 technicians |
| Melting | EF, LF, VOD, VIM, VAR, ESR. 60 t maximum heat |
| Forging | 6300 t, 4000 t and 2000 t presses; 6 m, 3 m and 1 m ring mills; hammers 750 kg to 5 t |
| Heat treatment | 14 furnaces, including high-temperature car-bottom and 15 m deep well furnaces |
| Approvals | CCS, BV, DNV, LR, NK |
| Volumetric NDT | EN 10228-3, SEP 1921, ASTM A388 |
| Certification | EN 10204-3.1, or 3.2 witnessed by a third party |
| Traceability | Heat number hard-stamped and carried on every certificate |
| Export markets | North America, Europe, Middle East, Asia-Pacific |
Positive material identification, grain size determination, intergranular corrosion testing and elevated-temperature tensile testing can be added to the inspection plan on request.
13
Questions we get asked
What is X9CrNiSiNCe21-11-2?
The EN name for heat resisting austenitic stainless steel 1.4835, standardised in DIN EN 10095 and equivalent to UNS S30815. It holds 20.0 to 22.0 % chromium, 10.0 to 12.0 % nickel and 1.40 to 2.50 % silicon, with 0.12 to 0.20 % nitrogen and 0.03 to 0.08 % cerium. Those last two elements separate it from 1.4828.
What is the equivalent of this grade?
EN 1.4835, UNS S30815, ASTM A240 and A479 grade S30815, and ISO 4955 grade X7CrNiSiNCe21-11. It is also listed as 253MA and X10CrNiSiN21-11. Trade names recorded against it include Therma 253 MA, Avesta 253 MA, RA 253 MA, BGH 4835 and Permodur 4835.
What is the maximum service temperature?
1150 °C is the highest application temperature in air. The grade is applied above 550 °C against hot gases and products of combustion, with warranted scaling resistance under wide and fast thermal fluctuation. There is no resistance in a reducing atmosphere. For load-bearing parts, design against the creep table rather than the scaling figure.
What heat treatment do the forgings get?
Softening or solution annealing at 1020 to 1120 °C for 5 to 20 minutes, cooled fast in air or water. That is the delivery condition. Stress relief at 850 to 950 °C for under 30 minutes with fast air cooling is a separate optional operation and does not replace solution annealing after forging.
What are the mechanical properties?
Annealed +AT at 20 °C: tensile strength 650 to 850 MPa, proof stress Rp0.2 of 310 MPa, elongation above 37 %, hardness below 210 HB, modulus of elasticity 200 kN/mm², density 7.80 kg/dm³.
Can it be used in wet or acid service?
No. Corrosion resistance is reduced compared with standard austenitic stainless steels and is not given in combination with water. The grade also has low resistance to oxidising sulphuric gases and none in a reducing atmosphere. For aqueous, chloride or offshore duty, specify a duplex grade such as A182-F51, F53 or F55, or a high-alloy austenitic such as 904L or A182-F44.
How does it differ from 1.4828?
Same base alloy, but with higher nitrogen and an addition of cerium. Those raise strength and creep resistance and keep the oxide layer attached during thermal cycling, so a thinner section will often carry the same duty.
Is it magnetic?
No, the structure is fully austenitic and the annealed material is non-magnetic. A local magnetic response can develop in and around welds. That is normal and is not a rejection criterion unless your specification says otherwise.
Who supplies these forgings?
Jiangyin Jiangnan Metal Co., Ltd., No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China. The works melts its own steel and forges rings, seamless rolled rings to 6000 mm outside diameter, flanges, discs, tube sheets, shafts, sleeves, bushings and bars up to 30 tonnes per piece, certified to EN 10204-3.1 or 3.2. Telephone +86 189 2135 9659, email sales@steelforgepieces.com.
What is the minimum order?
10 kg, with no minimum piece count. Single prototype forgings are accepted because open-die forging needs no dies. Lead time is normally 20 to 60 days depending on size, heat treatment and machining scope.
14
Standards and reference
Reference this datasheet as:
Jiangyin Jiangnan Metal Co., Ltd. X9CrNiSiNCe21-11-2 (EN 1.4835 / UNS S30815) forgings: composition, properties and heat treatment. steelforgepieces.com, revised 11 October 2026. https://www.steelforgepieces.com/Stainless-Steel/X9CrNiSiNCe21-11-2.html
Standards referenced on this page:
- DIN EN 10095:2018-12, heat resisting steels and nickel alloys, superseding DIN EN 10095:1999-05
- EN 10088-1, stainless steels, list of grades
- ISO 4955, heat resisting steels
- ASTM A240 and ASTM A479, UNS S30815
- EN 10228-3, SEP 1921 and ASTM A388, ultrasonic examination of forgings
- EN 10204, types of inspection documents
Figures are compiled for engineering guidance from the current standard and published mill datasheets. Confirm every design-critical value against the governing standard and your own design code before use. A plain text version of this page is available at X9CrNiSiNCe21-11-2.md.