Alleima® 253 MA steel is an austenitic stainless steel with high chromium and nickel content, alloyed with nitrogen and rare earth metals, designed to offer:
• Very high creep resistance.
• Excellent resistance to isothermal and cyclic oxidation.
• Good structural stability at high temperatures.
• Excellent weldability.
This material is ideal for high-temperature applications, with a maximum service temperature of approximately 1150°C (2100°F).

Reference standards:

• ASTM A213, A312
• EN 10297-2
• SS 2368
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Chemical composition (%)

Element Nominal value (%)
Carbon (C) 0.08
Silicon (Si) 1.6
Manganese (Mn) ≤0.8
Phosphorus (P) ≤0.040
Sulfur (S) ≤0.030
Chromium (Cr) 21
Nickel (Ni) 11
Nitrogen (N) 0.17
Rare earth metals (Ce + others) 0.05
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Mechanical properties at 20°C

Property Value
Yield strength Rp0.2 ≥310 MPa
Yield strength Rp1.0 ≥350 MPa
Tensile strength (Rm) 650–850 MPa
Elongation A5 ≥40%
Hardness ≈190 HV
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Physical properties

Property Value
Density 7.8 g/cm³
Modulus of elasticity 200 GPa
Thermal conductivity (20°C) 13 W/m·K
Electrical resistivity (20°C) 0.84 µΩ·m
Coefficient of thermal expansion (20-100°C) 16.5×10⁻⁶ /°C
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Corrosion resistance

• Excellent resistance to oxidation up to 1150°C in air, under both isothermal and cyclic conditions.
• Good resistance to carburization in hydrocarbon-containing atmospheres.
• Resistant to environments containing sulfur and other aggressive compounds at high temperatures.
• More corrosion resistant than ASTM TP310 and TP309 in oxidation cycles.
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Heat treatments

• Stress relief annealing: 850–950°C, followed by air cooling.
• Solution annealing: 1050–1150°C, followed by rapid cooling in air or water.
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Available formats

• Seamless tubes (up to Ø 260 mm)
• Welded tubes
• Plates and sheets
• Wires and bars
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Industrial applications

Thanks to its excellent resistance to creep, oxidation, and carburization, Alleima® 253 MA is used in:
• Heat recovery systems (e.g., industrial recuperators).
• Heat treatment furnaces (radiant tubes, thermocouple protection tubes).
• Fluidized bed combustion plants.
• Metallurgical, petrochemical, and power generation industries.
• Tubes in glass and cement processing furnaces.
• Reactor tubes for styrene production.
• Ethylene cracking tubes.
• Preheater tubes for sulfuric acid.