Jiangsu Liangyi Co., Limited holds ISO 9001:2015 Quality Management System certification, maintained under annual third-party audit by an internationally accredited certification body. This is our only company-held certification.
We manufacture to the technical requirements of international standards including EN, ASTM, and API — but we do not hold API 6A, PED 2014/68/EU, ISO 14001, ASME, DNV, BV, ABS, or Lloyd's Register company certifications. Third-party inspection by these bodies can be arranged per order at the customer's request. Customers requiring specific project certifications should verify compliance requirements with their own engineering team.
Identity: what exactly is 1.4835?
EN 1.4835, chemically designated X9CrNiSiNCe21-11-2, is an austenitic heat-resistant stainless steel engineered for continuous service at 850°C to 1100°C, with peak oxidation resistance up to 1150°C. It is standardised under UNS S30815 in the American system and SS 2368 in the original Swedish standard. The alloy is commonly referenced by the trade name 253 MA®, which is a registered trademark of Outokumpu OYJ; other mills produce compliant grades under the UNS S30815 designation.
Unlike conventional austenitic grades such as 304 or 316, which are optimised for ambient-temperature corrosion resistance, 1.4835 was designed specifically for oxidation resistance and creep strength at extreme temperatures. Its defining alloying innovation — the deliberate addition of cerium (Ce) alongside elevated silicon and nitrogen — makes it unique among all EN 10095-classified grades.
1.4835 is classified under EN 10095:1999 (Heat resisting steels and nickel alloys), not the general-purpose EN 10088 stainless steel series. This distinction matters when specifying material certificates, verifying code compliance under EN 13480 or PED 2014/68/EU, and confirming inspection requirements with notified bodies.
The grade bridges the performance gap between standard 18–8 austenitic stainless steels and expensive nickel-base superalloys. In the 850–1100°C range, 1.4835 outperforms Grade 310S (1.4845) in cyclic oxidising atmospheres at substantially lower alloy cost — its nickel content (10–12%) is roughly half that of 310S (19–22%).
Chemical composition per EN 10095:1999
The chemical composition of 1.4835 is tightly controlled by EN 10095:1999. Every element serves a specific metallurgical purpose in the high-temperature performance envelope.
| Element | Min % | Max % | Engineering role |
|---|---|---|---|
| C — Carbon | 0.05 | 0.12 | Moderate level for high-temperature strength; low enough to preserve corrosion resistance |
| Si — Silicon | 1.40 | 2.50 | Forms a dense SiO₂ sub-layer beneath Cr₂O₃, improving cyclic oxidation resistance |
| Mn — Manganese | — | 1.00 | Deoxidiser; minor contribution to austenite stability |
| Cr — Chromium | 20.0 | 22.0 | Primary former of protective Cr₂O₃ scale; baseline oxidation and corrosion resistance |
| Ni — Nickel | 10.0 | 12.0 | Austenite stabiliser; contributes to ductility and sigma-phase resistance |
| N — Nitrogen | 0.12 | 0.20 | Solid-solution strengthener; improves creep strength and resists sigma-phase precipitation |
| Ce — Cerium | 0.03 | 0.08 | Rare-earth addition anchoring the Cr₂O₃ scale, preventing spallation under thermal cycling |
| P — Phosphorus | — | 0.045 | Residual impurity; low level prevents hot cracking |
| S — Sulphur | — | 0.015 | Residual impurity; controlled low to ensure hot workability |
The combination of high Si + high N + Ce is unique among standardised austenitic stainless steels. No other EN 10095 grade carries all three simultaneously at these concentrations — and this triad is why 1.4835 maintains protective oxide scale integrity through repeated heating-and-cooling cycles.
Why cerium is the differentiating element
Cerium additions of 0.03–0.08% appear trivially small, but their metallurgical effect is disproportionately large. Understanding why requires examining the primary failure mechanism in conventional heat-resistant steels under thermal cycling.
The oxide spallation problem
At high temperatures, austenitic stainless steels form a chromium oxide (Cr₂O₃) scale that acts as a diffusion barrier. Under thermal cycling — heating to 900–1050°C followed by cooling — the thermal expansion mismatch between the Cr₂O₃ layer and the metal substrate generates shear stress at the interface. In standard grades including 310S, these stresses cause progressive oxide spallation: the scale detaches, exposes fresh metal, and the cycle repeats until through-wall attack occurs.
How cerium anchors the scale
Cerium atoms preferentially segregate to oxide grain boundaries and the oxide-metal interface, producing two concurrent protective effects:
- Interface adhesion: Ce modifies Cr₂O₃ grain boundary chemistry, forming Ce-enriched oxide pegs that mechanically interlock with the substrate — resisting the shear forces generated by thermal cycling.
- Scale growth rate reduction: Cerium partially substitutes into the Cr₂O₃ lattice, reducing cation diffusion. A slower-growing scale is thinner, more coherent, and less prone to cracking under cyclic mechanical stress.
In standardised cyclic oxidation tests at 1000°C (1-hour cycles, air atmosphere), 1.4835 exhibits mass gains approximately 60–70% lower than AISI 310S after 500 cycles. This directly translates to extended service life in industrial furnaces, kilns, and heat exchangers under thermal cycling duty.
The Ce + Si synergy
Cerium's effectiveness is amplified by the elevated silicon content (1.4–2.5%). Silicon promotes a thin SiO₂ sub-layer beneath the Cr₂O₃ scale that reinforces the mechanical anchoring of the outer chromia scale and provides a secondary diffusion barrier when the chromia is locally breached. The Ce + Si combination delivers oxidation performance exceeding what either element alone would predict.
Mechanical properties at room temperature
Values below reflect the solution annealed condition (1050–1150°C, water or air quench) — the standard delivery condition for 1.4835 forgings per EN 10095:1999.
Physical properties
| Property | Value | Notes |
|---|---|---|
| Melting range | ~1400–1450°C | Solidus to liquidus |
| Thermal conductivity | 15–20 W/(m·K) | Room temperature |
| Mean CTE (20–200°C) | ~16.0 × 10⁻⁶ /K | Solution annealed |
| Mean CTE (20–800°C) | ~18.5 × 10⁻⁶ /K | Solution annealed |
| Electrical resistivity | ~0.90 μΩ·m | Room temperature |
| Magnetic permeability | Non-magnetic (μ ≈ 1.02) | May become slightly magnetic after cold working or welding |
| Specific heat capacity | ~500 J/(kg·K) | Room temperature |
The CTE of 1.4835 is approximately 10–15% higher than ferritic and martensitic heat-resistant steels. In mixed-material assemblies — for example, 1.4835 components bolted to ferritic supports — differential expansion during heatup and cooldown must be explicitly accounted for in joint design to prevent fatigue cracking at material interfaces.
Performance at elevated temperatures
The engineering value of 1.4835 is realised above 550°C. Below that threshold, standard austenitic grades are generally more economical. Above 850°C, 1.4835 is among the most cost-effective austenitic materials before entering nickel-base alloy territory.
Strength vs. temperature (indicative values)
| Temperature | 0.2% Rp — typical (MPa) | Tensile Rm — typical (MPa) |
|---|---|---|
| 20°C (room temperature) | ≥ 310 | ≥ 600 |
| 300°C | ~ 185 | ~ 480 |
| 500°C | ~ 150 | ~ 390 |
| 700°C | ~ 110 | ~ 280 |
| 900°C | ~ 55 | ~ 120 |
| 1000°C | ~ 30 | ~ 70 |
Indicative values for solution-annealed material. Engineering design must use certified material test certificates from the actual heat and heat treatment batch.
Comparative cyclic oxidation resistance at 1000°C in air
Relative performance normalised to 1.4835 = 100% (standardised 1-hour cycle test, air atmosphere):
Atmosphere compatibility
| Atmosphere | Max continuous temp | Notes |
|---|---|---|
| Dry air / oxidising | 1150°C | Excellent — primary application domain |
| Reducing / H₂ | 950°C | Good — avoid sulphur contamination |
| Sulphur-bearing | 850°C | Moderate — assess H₂S concentration case by case |
| Nitriding | 800°C | Limited — surface nitridation accelerates over time |
| Carburising | 900°C | Moderate — grade 1.4852 preferred for severe carburising |
International grade cross-reference for 1.4835
1.4835 is standardised under multiple international designations. The table below covers all designations engineers commonly encounter in global procurement and project specifications.
| Standard system | Designation | Notes |
|---|---|---|
| EN (European) | 1.4835 / X9CrNiSiNCe21-11-2 | EN 10095:1999 — primary reference standard |
| UNS (ASTM / AISI) | S30815 | ASTM A240, A312; no AISI letter grade assigned |
| Trade name | 253 MA® | Registered trademark of Outokumpu OYJ — identifies the alloy spec only |
| Swedish (SIS) | SS 2368 | Original Swedish designation, pre-EN harmonisation |
| Alleima trade name | Alleima 253 MA | Alleima AB's own compliant grade — trademark of Alleima AB |
| BS (UK) | No direct equivalent | Specify by UNS S30815 or EN 1.4835 in UK project docs |
| JIS (Japan) | No direct JIS equivalent | Specify by UNS S30815 in Japanese project documentation |
For projects governed by European codes (EN 13480, EN 12952, PED 2014/68/EU), explicitly specify EN 10095:1999 compliance and request EN 10204 Type 3.1 or 3.2 mill test certificates. Certificates referencing only UNS S30815 / ASTM A240 may not satisfy European notified body requirements without supplementary documentation.
1.4835 vs 310S (1.4845) vs 304H (1.4948)
These three austenitic grades are most commonly evaluated together when selecting material for high-temperature process equipment.
| Parameter | 1.4835 (UNS S30815) | 1.4845 (310S) | 1.4948 (304H) |
|---|---|---|---|
| Chromium content | 20–22% | 24–26% | 17.5–19.5% |
| Nickel content | 10–12% | 19–22% | 8–10% |
| Special alloying | Ce + Si + N (unique) | None | C ≥ 0.04% |
| Max service temp (oxidising) | 1150°C | 1100°C | 870°C |
| Cyclic oxidation resistance | ★★★★★ Excellent | ★★★★ Good | ★★ Moderate |
| Sigma-phase susceptibility | Low | Moderate–High | Low |
| Relative alloy cost | Medium | High | Low–Medium |
| Weldability | Good | Good | Excellent |
| Governing EN standard | EN 10095 | EN 10095 | EN 10088 |
When to choose 1.4835 over 310S
Select 1.4835 when the application involves thermal cycling — repeated heatup and cooldown cycles — because the cerium addition dramatically reduces oxide spallation versus 310S. 310S is defensible for isothermal high-temperature service. The lower nickel content of 1.4835 (roughly half that of 310S) also delivers a significant raw material cost advantage per kilogram.
When 304H is sufficient
If maximum continuous operating temperature is reliably below 800°C and thermal cycling is infrequent, 304H delivers adequate oxidation resistance at lower cost. The crossover point where 1.4835 becomes more economical on a lifecycle basis is typically around 800–850°C when component replacement and downtime costs are factored in.
Industrial applications of 1.4835 forged components
1.4835 is specified across multiple industries wherever sustained or cyclic high-temperature exposure is combined with mechanical load requirements that preclude purely refractory or ceramic materials.
Radiant tubes, muffles, retorts, hearth rolls, and roller conveyor components for continuous and batch annealing furnaces in steel, aluminium, and ceramics processing.
Catalyst support rings, inlet manifold components, and flange forgings for steam methane reformers and catalytic crackers at 850–1000°C.
Grate bars, stoker components, and afterburner nozzle forgings in municipal solid waste and hazardous waste incinerators in sulphur- and chlorine-bearing flue gases.
HRSG components, flue gas desulphurisation fittings, and combustion air preheater forgings in gas and biomass power plants.
Kiln riding rings, support rollers, and clinker cooler components requiring simultaneous resistance to thermal cycling, abrasion, and alkaline atmospheres.
Stirrer shafts, electrode holders, and forehearth channel components where oxide scale spallation contamination of the glass melt cannot be tolerated.
Tube support fittings, burner block holders, and fired heater structural components in crude distillation units at skin temperatures above 750°C.
Reactor internals, heat exchanger flanges, and valve components in nitric acid, sulphuric acid, and chlorinated processes at high temperature.
Typical forged product forms — Jiangsu Liangyi Co., Limited
| Product form | Size range | Typical application |
|---|---|---|
| Round bar / shaft forging | ∅50 – 800 mm | Roller axles, stirrer shafts, radiant tube supports |
| Flat bar / slab forging | T20–200 mm × W up to 1,500 mm | Grate bar blanks, structural supports, plate flanges |
| Seamless rolled ring | ∅200 – 3,000 mm | Kiln riding rings, retort flanges, bearing rings |
| Disc / block forging | ∅100–1,500 mm, T up to 500 mm | Valve body blanks, flange blanks, manifold billets |
| Custom section (per drawing) | Up to 30 tons per piece | Muffles, retort end caps, burner nozzle blanks |
All products are supplied with EN 10204 Type 3.1 mill test certificates as standard. Type 3.2 (countersigned by an accredited third-party inspector nominated by the customer, such as TÜV, DNV, BV, ABS, or RINA) is available on request. For full dimensional ranges, size availability, and EN 10204 3.1/3.2 certification options, see our custom EN 1.4835 forged rings, bars, and open die forgings page.
Welding 1.4835: processes, filler metals, and best practices
1.4835 has good weldability and is compatible with all major arc welding processes. The key constraints are low heat input discipline, correct filler metal selection, and avoidance of post-weld heat treatment at intermediate temperatures that would promote sigma-phase formation.
Compatible welding processes
| Process | Suitability | Notes |
|---|---|---|
| GTAW / TIG | Excellent | Preferred for precision joints; best heat control |
| SMAW / MMA | Good | Most versatile on-site; use basic or rutile electrodes |
| GMAW / MIG-MAG | Good | High deposition rate; spray or pulsed transfer preferred |
| PAW (Plasma Arc) | Good | Suitable for thin-section work |
| SAW (Submerged Arc) | Acceptable | High heat input risk — not preferred for 1.4835 |
| Laser / Electron Beam | Good | Excellent heat control; requires qualified setup |
Filler metal selection
Use AWS A5.9 ER253MA matching filler metal. Do not substitute 308L or 316L — these lack the Ce, elevated Si, and N required to maintain oxidation resistance through the weld joint. Mismatched fillers create a localised weak point in the oxide scale at the weld toe: consistently the first location to fail in cyclic high-temperature service.
Maximum recommended heat input for 1.4835 is 1.5 kJ/mm. Higher heat input promotes sensitisation (Cr carbide precipitation at grain boundaries) and sigma-phase formation in the heat-affected zone. Maximum interpass temperature: 150°C. Allow the weld zone to cool between passes on multi-pass welds.
Pre- and post-weld treatment
Preheating is not required or recommended — the austenitic structure means there is no martensitic transformation risk, and preheating would increase effective heat input. Post-weld heat treatment (PWHT) is generally not performed in normal service. Where a pressure code mandates stress relief, solution annealing at 1050–1150°C followed by rapid quench is the only acceptable route. Stress relief at intermediate temperatures (550–900°C) would cause carbide precipitation and sigma-phase formation.
Cold and hot forming
Hot forming should be carried out at 900–1200°C, followed by solution annealing if maximum ductility and corrosion resistance are required. Cold forming requires higher forces than 304 due to the elevated nitrogen increasing the work-hardening rate. The steel cannot be hardened by heat treatment — only by cold working.
Manufacturing process and ordering guide
Jiangsu Liangyi Co., Limited has supplied EN 1.4835 open die forgings to buyers in over 50 countries since 1997. Understanding the manufacturing sequence and quality checkpoints helps you specify correctly and avoid delivery-stage surprises. Engineers ready to proceed can request a quote for 1.4835 (X9CrNiSiNCe21-11-2) forging parts directly from the product page.
We hold ISO 9001:2015 Quality Management System certification. We produce to the technical requirements of EN, ASTM, API, and other standards per customer specification, but we do not hold API 6A, PED 2014/68/EU, ISO 14001, or class society company certifications. Third-party inspection and countersignature (TÜV, DNV, BV, ABS, RINA) is arranged per order at customer request.
Electric arc furnace melting, vacuum degassing, and ladle refining for tight composition control to EN 10095:1999 limits. ESR electroslag remelting available for critical large forgings.
Minimum forging ratio 4:1 for grain refinement and elimination of as-cast dendritic structure. Large sections forged with intermediate reheats above 1100°C.
Computer-controlled batch furnaces with data logging. Rapid water quench to produce a fully austenitic, non-sensitised microstructure. Furnace charts supplied with MTC.
UT to EN 10228-3 / ASTM A388; MT or PT on all accessible surfaces; OES chemical analysis; Charpy impact and tensile testing per EN ISO 6892-1.
CNC rough-turned to drawing dimensions or as-forged with agreed allowance. CMM dimensional report available on request.
EN 10204 3.1 MTC issued as standard. Type 3.2 countersignature by customer-nominated TPI arranged on request. Located 150 km from Shanghai Port.
What to include in your enquiry
| Required information | Example |
|---|---|
| Material grade | EN 1.4835 / X9CrNiSiNCe21-11-2 per EN 10095:1999 |
| Product form and dimensions | Forged ring: OD 800 mm × ID 600 mm × H 120 mm |
| Quantity and required delivery | 5 pieces, required by Q4 2025 |
| Applicable standard | EN 10250-4 (open steel die forgings) |
| Certification requirement | EN 10204 3.1 MTC; 3.2 with customer-nominated TPI if required |
| NDE requirements | UT to EN 10228-3 Class 3; PT on all surfaces |
| Machining scope | As-forged / rough turned / semi-finish / finish |
| Drawing or 3D model | PDF drawing with all dimensions and tolerances |
1.4835 (X9CrNiSiNCe21-11-2) — frequently asked questions
EN 1.4835, chemically designated X9CrNiSiNCe21-11-2 (UNS S30815 / SS 2368), is an austenitic heat-resistant stainless steel designed for continuous service at 850°C to 1150°C. It is classified under EN 10095:1999 and is unique for containing cerium (Ce), elevated silicon (Si), and nitrogen (N) simultaneously — a combination that gives it exceptional cyclic oxidation resistance unmatched by standard austenitic grades.
The grade 1.4835 (UNS S30815) is commonly referenced by the trade name 253 MA®, which is a registered trademark of Outokumpu OYJ. Jiangsu Liangyi Co., Limited is not affiliated with Outokumpu OYJ. We manufacture forgings to the alloy specification EN 1.4835 / UNS S30815 per EN 10095:1999.
1.4835 (X9CrNiSiNCe21-11-2 / UNS S30815) can withstand continuous service temperatures up to 1150°C in oxidising atmospheres. The optimal service range is 850–1100°C. In reducing or hydrogen atmospheres, the maximum recommended continuous temperature is 950°C.
Per EN 10095:1999: C 0.05–0.12%, Si 1.40–2.50%, Mn max 1.00%, Cr 20.0–22.0%, Ni 10.0–12.0%, N 0.12–0.20%, Ce 0.03–0.08%, P max 0.045%, S max 0.015%.
1.4835 outperforms 310S (1.4845) in cyclic oxidation resistance by approximately 60–70% at 1000°C in air, due to its cerium and silicon additions which prevent oxide spallation during thermal cycling. 310S has higher Cr (24–26%) and Ni (19–22%), making it more expensive, but lacks cerium — so its oxide scale spalls under repeated heating and cooling. For isothermal high-temperature service, 310S remains a valid choice.
Use AWS A5.9 ER253MA matching filler metal. Do not use 308L or 316L fillers — these lack the Ce, elevated Si, and N required to maintain oxidation resistance through the weld joint. Maximum heat input: 1.5 kJ/mm. Maximum interpass temperature: 150°C. Preheating is not required.
Jiangsu Liangyi Co., Limited holds ISO 9001:2015 Quality Management System certification, maintained under annual third-party audit. We do not hold API 6A, PED 2014/68/EU, ISO 14001, ASME, or class society company certifications. We produce to the technical requirements of these standards per customer specification, and third-party inspection (TÜV, DNV, BV, ABS, RINA) can be arranged per order at customer request.