Overview
Seamless 253MA Stainless Steel Pipe (UNS S30815, EN 1.4835, DIN X9CrNiSiNCe21-11-2) is a precipitation-strengthened austenitic alloy specifically engineered for high-temperature resistance and creep strength. Composed of 20-22% chromium, 10-12% nickel, 1.4-2.0% silicon, 0.05-0.15% carbon, and cerium (Ce) and nitrogen (N), this alloy combines the benefits of oxidation resistance with improved mechanical properties at elevated temperatures. Manufactured via seamless extrusion or piercing to ensure uniform grain structure and dimensional precision, it complies with standards like ASTM A213, ASME SA213, and EN 10216-5.
The addition of cerium stabilizes the oxide layer, while nitrogen enhances solid-solution strengthening, making 253MA superior to conventional 300-series steels in cyclic thermal loading conditions. Its austenitic microstructure remains non-magnetic and ductile, even after prolonged exposure to temperatures up to 1200°C.
Chemical Composition
| Grade | Cr | Ni | C | Si | Mn | P | S | N | Ce | Fe |
| 253MA | 20.00-22.00 | 10.00-12.00 | 0.05-0.10 | 1.40-2.00 | ≤0.08 | ≤0.04 | ≤0.03 | 0.14-0.20 | 0.03-0.08 | Balance |
Features
Exceptional High-Temperature Oxidation Resistance: Forms a dense Cr₂O₃-SiO₂ protective scale, resisting spalling and carburization at continuous service temperatures up to 1150°C, ideal for harsh furnace environments.
Creep & Fatigue Resistance: Maintains high tensile strength and ductility between 600–1000°C, outperforming TP310H in low-stress, high-temperature cyclic applications.
Corrosion Resistance in Mixed Atmospheres: Resistant to sulfurous gases, vanadium-induced corrosion, and mild chloride environments, though not optimized for highly reducing acids.
Ease of Fabrication: Readily weldable using GTAW/GMAW with matching filler metal (e.g., 253MA rod), and formable into complex shapes with moderate cold working.
Mechanical Properties
Grade | Tensile Strength ksi(MPa) | Yield Strength ksi(MPa) | Elongation in 2", % | Hardness Brinell | Hardness Rockwell |
253SMA | ≥87(600) | ≥45(310) | ≥40 | ≤217HBW | ≤95HRB |
Application
Industrial Furnaces: Used in radiant tubes, mesh belts, and furnace rollers for heat treatment plants, cement kilns, and glass annealing lehrs.
Energy from Waste: Ideal for boiler tubes and incinerator components exposed to chlorine-rich flue gases and thermal cycling.
Petrochemical Reforming: Employed in steam reformer tubes and ethylene furnace coils where resistance to coking and scale formation is critical.
Aerospace Heat Exchangers: Suitable for lightweight components in auxiliary power units (APUs) requiring high-temperature durability.
Material Summary
Despite its lean nickel content, 253MA offers an outstanding combination of creep strength and high resistance to oxidation, sulphidation and erosion/abrasion at extremely high temperatures. This makes the alloy more economical than most heat resistant alloys.
The high heat resistant properties of 253MA are obtained by the tight control of micro alloy additions. Whilst the benefit of creep rupture strength is down to the combination of nitrogen, carbon and cerium, its superior oxidation resistance is a result of the combination of cerium and silicon.
Its strength at these temperatures is higher than that of alternatives such as Grade 310.
