Key Feature

The Premium High-Temperature Austenitic Piping Solution. Exceptionally high chromium and nickel content provides outstanding oxidation resistance and strength at temperatures up to 1150°C for piping systems.

The standard material for high-temperature furnace piping and heat-resistant applications.

Common Designations

UNS S31008
AISI 310S
ASTM A312 TP310S (Seamless/Welded)
EN 1.4845, X8CrNi25-21
JIS SUS310S

"S" indicates low carbon version; standard 310 has higher carbon (≤0.25%).

Chemical Composition (Typical wt.%)

C: ≤ 0.08
Cr: 24.0 - 26.0Ni: 19.0 - 22.0Mn: ≤ 2.00
Si: ≤ 1.50
P: ≤ 0.045
S: ≤ 0.030

High Cr provides oxidation resistance; high Ni ensures austenite stability at high temperatures.

Mechanical Properties

Tensile Strength: ≥ 515 MPa
Yield Strength: ≥ 205 MPa
Elongation: ≥ 40%
Hardness: ≤ 217 HB

Good room-temperature properties, but designed for elevated temperature performance.

Elevated Temperature Properties

Continuous Service: Up to 1150°C
Intermittent Service: Up to 1100°C
Creep Strength: Excellent up to 1000°C
Oxidation Resistance: Excellent up to 1100°C

Superior to 304/316 grades above 800°C; maintains strength better at high temperatures.

Physical Properties

Density: 7.98 g/cm³
Melting Range: 1400 - 1450 °C
Thermal Expansion: 15.9 × 10⁻⁶/K (20-100°C)
Thermal Conductivity: 14.2 W/m·K (100°C)
Non-magnetic when annealed

Higher density than 304; thermal expansion similar to other austenitics.

Corrosion Resistance

Excellent oxidation resistance at high temperatures. Good general corrosion resistance similar to 304 at room temperature. Not designed for chloride-rich environments.

High chromium provides good corrosion resistance, but limited chloride resistance.

Welding Characteristics

Good weldability with standard methods
310S preferred over 310 for welding
Possible sigma phase formationPost-weld solution annealing recommended

Must control heat input and cooling rate to prevent embrittlement.

Pressure-Temperature Ratings

At 800°C: ~30% of room temp strength
At 900°C: ~20% of room temp strength
At 1000°C: ~10% of room temp strength
ASME B31.3 compliant

Significant strength reduction at high temperatures requires careful design.

Key Standards

ASTM A312 TP310S: Seamless & Welded Pipe
ASTM A358 TP310S: EFW Pipe
ASTM A213 TP310S: Boiler Tubes
EN 10216-5: Seamless Pressure Tubes
ASME SA312: Code Construction
ISO 1127: Stainless Steel Tubes

Comprehensive standardization for quality assurance.

Common Applications

• Furnace Piping: Radiant tubes, retort piping, furnace exhaust systems
• Heat Treatment Systems: Annealing line piping, carburizing systems, hardening lines
• Thermal Processing: Kiln piping, pyrolysis systems, calciner tubes
• Power Generation: Superheater tubes, boiler components, high-temperature ducting
• Chemical Processing: High-temperature reactor piping, reformer systems, pyrolysis tubes
• Aerospace: Afterburner piping, exhaust ducting systems
• Glass Manufacturing: Lehr piping, mold handling systems

Specifically designed for continuous high-temperature operation in piping systems.