X15CrNiSi20-12 (1.4828 / AISI 309) Open-Die Forgings
Forged rings, seamless rolled rings, flanges, shafts, round bars, discs, sleeves, bushings and tube sheets, made to drawing by Jiangyin Jiangnan Metal Co., Ltd., Jiangyin, Jiangsu, China.
X15CrNiSi20-12 is the EN designation for heat-resisting austenitic stainless steel 1.4828, equivalent to AISI 309 and UNS S30900. It is a chromium-nickel-silicon steel standardised in EN 10095 (heat-resisting steels and nickel alloys). It is scaling-resistant in air to about 1000 C, with a normal service window of 800 to 1000 C. Its wet-corrosion resistance is rated low, so the grade belongs in hot-gas and furnace duty rather than aqueous service. Jiangyin Jiangnan Metal Co., Ltd. supplies it as open-die forgings and seamless rolled rings to customer drawing.
- EN / DIN
- X15CrNiSi20-12, material no. 1.4828
- AISI / UNS
- 309 / S30900
- Other IDs
- BS 309S24, AFNOR Z15CNS20.12, JIS SUH309, PN H20N12S2
- Structure
- Austenitic, not hardenable by heat treatment
- Max. scaling temp.
- about 1000 C in air
- Forging range
- 1150 to 800 C, rapid air or water cooling
1. Grade designations and equivalents
| EN number | EN name | AISI/SAE | UNS | BS | AFNOR | JIS |
|---|---|---|---|---|---|---|
| 1.4828 | X15CrNiSi20-12 | 309 | S30900 | 309S24 | Z15CNS20.12 | SUH309 |
Equivalents are indicative. Grades listed across national standards are not always chemically identical, so confirm the ordering standard on the enquiry.
2. Chemical composition (EN 10095)
| Element | C | Si | Mn | P | S | Cr | Ni | N | Fe |
|---|---|---|---|---|---|---|---|---|---|
| min | - | 1.50 | - | - | - | 19.0 | 11.0 | - | Balance |
| max | 0.20 | 2.50 | 2.00 | 0.045 | 0.015 | 21.0 | 13.0 | 0.11 |
Limit values per EN 10095. The silicon content near 2 % is what lifts the scaling resistance of this grade above the ferritic furnace steels.
3. Mechanical properties at 20 C (solution annealed)
| Property | Metric | Imperial |
|---|---|---|
| Tensile strength Rm | 550 to 750 N/mm² | 80 to 109 ksi |
| Yield strength Rp0.2 | min. 230 N/mm² | min. 33 ksi |
| Yield strength Rp1.0 | min. 270 N/mm² | min. 39 ksi |
| Elongation A5 | min. 30 % | min. 30 % |
| Hardness | max. 223 HB | max. 223 HB |
| Modulus of elasticity | 196 kN/mm² | 28.4 x 10³ ksi |
4. Physical properties at 20 C
| Density | Specific heat capacity | Thermal conductivity (20 C) | Thermal conductivity (500 C) | Electrical resistivity | Microstructure |
|---|---|---|---|---|---|
| 7.9 kg/dm³ | 500 J/kg·K | 15 W/m·K | 21 W/m·K | 0.85 Ω·mm²/m | Austenitic |
5. Heat resistance and corrosion behaviour
X15CrNiSi20-12 is a heat-resisting grade, not a wet-corrosion grade. That distinction decides most specification errors with this material. Published mill data rates its corrosion resistance as low, its mechanical properties as medium, and its forgeability, weldability and machinability as good.
| Environment | Reported limit |
|---|---|
| Scaling resistance in air | up to about 1000 C (oxidation in air quoted from about 950 C upward, depending on source) |
| Normal application range | about 800 to 1000 C |
| Oxidising or reducing sulphur-bearing gases | limited, use restricted to about 650 C |
| Carburising or low-oxygen nitrogen-bearing gases | limited resistance above about 900 C |
| Hot gases and combustion products | resistant above 550 C |
Where thermal cycling is severe, specifiers often move to 1.4845 (310S), which forms a more adherent scale than the 309-type grades under intermittent heating and cooling.
6. Forging, heat treatment and fabrication
Forging
Forge between 1150 C and 800 C, then cool rapidly in air or water. The alloy work-hardens and conducts heat poorly, so passes are planned to keep the stock above the lower limit and to avoid finishing in the carbide-precipitation range.
Heat treatment
Solution annealing (+AT) at 1050 to 1150 C, cooled in water or air. The grade is austenitic and cannot be hardened by heat treatment. Properties are set by forging reduction and section size, not by quench and temper.
Welding
Weldable by the usual processes, including TIG, MAG, arc and resistance welding. Preheating and post-weld heat treatment are not required. Filler metal 1.4829 is cited as suitable.
Machining
Carbide formation during cutting raises tool wear. Use high-quality tooling, plenty of coolant, and moderate cutting speeds and depths of cut.
7. Forged products we supply in X15CrNiSi20-12
8. Typical applications of 1.4828 forgings
Reported application fields for this grade are furnace construction and high-temperature apparatus engineering, sieves and grates, the cement industry, chemical and petrochemical plant, the chain industry, general mechanical engineering, the automotive sector and construction. In forged form that usually means furnace rolls and roller ends, retort and radiant-tube components, burner and nozzle parts, grate bars, hanger and support rings, recuperator flanges and tube sheets, expansion-joint rings, and heat-treatment fixture hardware.
If the duty is aqueous or acid corrosion rather than hot gas, this is usually the wrong grade. Ask us instead about 904L, A182-F51, A182-F55 or Incoloy 825.
9. 1.4828 compared with neighbouring heat-resisting grades
| EN no. | EN name | AISI | C max % | Si % | Cr % | Ni % | Reported heat or scaling limit |
|---|---|---|---|---|---|---|---|
| 1.4828 | X15CrNiSi20-12 | 309 | 0.20 | 1.50-2.50 | 19.0-21.0 | 11.0-13.0 | about 1000 C in air |
| 1.4833 | X12CrNi23-13 | 309S | 0.15 | max 1.0 | 22-24 | 12-14 | heat-resistant to about 1000 C, creep-resistant to about 700 C |
| 1.4845 | X8CrNi25-21 | 310S | - | - | about 25 | about 21 | to about 1050 C, more adherent scale under thermal cycling |
| 1.4841 | X15CrNiSi25-21 | 310 / 314 | - | Si-alloyed | about 25 | about 21 | scale-resistant to about 1150 C |
Composition figures for 1.4833 are EN 10095 limit values. The 1.4845 and 1.4841 rows are nominal and shown for orientation only. Temperature limits vary between publishers and with atmosphere, so request a grade-specific datasheet before fixing a design limit.
10. Manufacturing route, testing and certification
Material is melted by EAF plus VOD, with ESR available where a tighter cleanliness level is specified. Forging is carried out on open-die presses and hammers, with ring rolling for ring geometries. Ultrasonic examination follows the standard nominated by the customer, normally EN 10228-3, SEP 1921 or ASTM A388. Certification is issued to EN 10204 3.1, with 3.2 third-party certification available on request. Mechanical testing, PMI, grain-size and intergranular-corrosion testing can be added to the inspection plan. State the acceptance class and inspection scope with the enquiry.
11. How to order
Send a drawing, or a description with the main dimensions, and include the following so the quotation can be firm: grade and ordering standard, for example X15CrNiSi20-12 to EN 10095; rough or finished dimensions and tolerances; quantity; delivery condition, such as as-forged, solution annealed +AT or rough machined; NDT and acceptance standard; certification level; and the service temperature and atmosphere, so the grade choice can be confirmed before cutting metal.
12. Frequently asked questions
What is X15CrNiSi20-12?
It is the EN name for heat-resisting austenitic stainless steel 1.4828, equivalent to AISI 309 and UNS S30900. Composition is 19.0 to 21.0 % Cr, 11.0 to 13.0 % Ni, 1.50 to 2.50 % Si and max 0.20 % C, covered by EN 10095 for heat-resisting steels and nickel alloys.
What is the maximum service temperature of 1.4828?
Scaling-resistant in air to about 1000 C, with a normal application range of 800 to 1000 C. The limit falls to about 650 C in oxidising or reducing sulphur-bearing gases, and resistance is limited above about 900 C in carburising or low-oxygen nitrogen-bearing atmospheres.
Is X15CrNiSi20-12 corrosion resistant?
Its wet-corrosion resistance is rated low. The grade is chosen for high-temperature oxidation and scaling resistance, not for aqueous, acid or chloride service. For those duties a duplex, super-austenitic or nickel-alloy grade is the right choice.
Is 1.4828 the same as 1.4833?
No. X15CrNiSi20-12 is 1.4828 (AISI 309). 1.4833 is X12CrNi23-13 (AISI 309S), with max 0.15 % C, max 1.0 % Si, 22 to 24 % Cr and 12 to 14 % Ni. They are neighbouring EN 10095 grades, not two names for one material.
What are the forging and annealing temperatures?
Forge between 1150 C and 800 C, with rapid air or water cooling afterwards. Solution anneal at 1050 to 1150 C, cooling in water or air.
Can 1.4828 be welded and machined?
Yes. All common welding processes are suitable, and neither preheat nor post-weld heat treatment is required. Filler 1.4829 is cited as suitable. Machining calls for good tooling, strong cooling and reduced speeds and depths of cut, because of carbide formation and work hardening.
Who supplies X15CrNiSi20-12 forgings?
Jiangyin Jiangnan Metal Co., Ltd., an open-die forging factory at No.1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, produces X15CrNiSi20-12 forged rings, seamless rolled rings, flanges, shafts, bars, discs, sleeves, bushings and tube sheets to customer drawing. Contact sales@steelforgepieces.com or 0086-189-2135-9659.
Request a quotation for X15CrNiSi20-12 forgings
Send a drawing or the main dimensions, and we will quote weight, delivery condition and lead time.
Open-Die Forging Factory
Jiangyin City, Jiangsu Province, China
Related grades
AISI 321H · AISI 347H · AISI 330 · A182-F321 · Incoloy 800H · Incoloy 800HT · Inconel 601 · Haynes 230
Technical data on this page follows published EN 10095 limit values and public mill datasheets for 1.4828 / X15CrNiSi20-12. It is given for guidance and is not a warranty of properties. Values for a specific order are confirmed on the material certificate. Page reviewed by Jiangyin Jiangnan Metal Co., Ltd.