ASTM A312 TP309Cb Austenitic Stainless Steel Pipe
ASTM A312 TP309Cb (UNS S30940) is a niobium-stabilized, high-temperature austenitic stainless steel grade designed for enhanced strength, exceptional oxidation resistance, and stability under thermal cycling. The addition of columbium (Cb/Nb) prevents carbide precipitation, making it ideal for elevated-temperature and pressure applications.
This grade is widely used in refineries, petrochemical heaters, boilers, thermal processing units, and furnace components where prolonged service at extreme temperatures is required.
Key Features
- UNS S30940 Nb-stabilized high-temperature stainless steel
- Excellent resistance to oxidation up to 1050°C
- High creep strength and structural stability
- Superior resistance to carburization & thermal fatigue
- Smooth corrosion resistance in sulfidation and reducing atmospheres
- Ideal for continuous and cyclic high-temperature exposure
- Precision-made as Seamless / ERW / Welded / EFW pipes
- Excellent weldability & dimensional accuracy
Equivalent Grades
| Standard |
Equivalent Grade |
| UNS |
S30940 |
| WNR |
1.4833 (Approx. reference) |
| EN |
X12CrNi23-13 (Comparable) |
| JIS |
SUS 309 Modified |
Available Sizes
Outside Diameter (OD):
Wall Thickness (WT):
Pipe Lengths:
- Single Random (SRL)
- Double Random (DRL)
- Cut-to-Length (Custom)
ASTM A312 TP309Cb Chemical Composition
| Element |
Content (%) |
| Carbon (C) |
≤ 0.08 |
| Chromium (Cr) |
22.0 – 24.0 |
| Nickel (Ni) |
12.0 – 15.0 |
| Manganese (Mn) |
≤ 2.00 |
| Silicon (Si) |
≤ 1.00 |
| Sulfur (S) |
≤ 0.030 |
| Phosphorus (P) |
≤ 0.045 |
| Columbium (Nb/Cb) |
Stabilized (0.3 – 1.0 typical) |
| Iron (Fe) |
Balance |
ASTM A312 TP309Cb Mechanical Properties
| Property |
Value |
| Tensile Strength |
≥ 620 MPa |
| Yield Strength (0.2% Proof) |
≥ 310 MPa |
| Elongation |
≥ 40% |
| Hardness (HBW) |
≤ 192 |
ASTM A312 TP309Cb Physical Properties
| Property |
Value |
| Density |
7.98 g/cm³ |
| Melting Point |
1398 – 1454°C |
| Thermal Conductivity |
14.2 W/m·K (at 100°C) |
| Electrical Resistivity |
0.78 µΩ·m |
| Modulus of Elasticity |
193 GPa |
| Specific Heat |
500 J/kg·K |
Available Types
- Seamless Stainless Steel Pipes
- Welded Stainless Steel Pipes
- ERW Pipes
- EFW Pipes
- Annealed & Pickled Pipes
- Polished Pipes (180–600 Grit)
- Fabricated / Custom Pipes
Applications
- Petrochemical heaters & reforming units
- High-temperature furnace tubing
- Thermal processing systems
- Boiler & superheater tubes
- Heat exchangers operating at elevated temperatures
- Kiln and combustor components
- Power generation & waste incineration units
- Chemical processing & refining equipment
Reviews
There are no reviews yet.