ASTM A312 TP348H Austenitic Stainless Steel Pipe
ASTM A312 TP348H (UNS S34800) is an advanced austenitic stainless steel pipe grade derived from 347H, designed for elevated-temperature service and enhanced stability. The addition of columbium/niobium provides resistance against intergranular corrosion, while the higher carbon content improves high-temperature mechanical and creep properties. TP348H stainless steel pipes are widely used in boilers, petrochemical systems, superheaters, and other heat-intensive environments.
Key Features
- High-carbon, niobium-stabilized austenitic stainless steel
- Excellent resistance to intergranular corrosion
- Enhanced creep and stress-rupture strength at high temperatures
- Superior oxidation resistance in heat-service conditions
- Stable mechanical properties under long-term thermal exposure
- Good weldability and fabrication characteristics
- Suitable for severe high-temperature and corrosive environments
Equivalent Grades
| Standard |
Grade |
| ASTM |
TP348H |
| UNS |
S34800 |
| WNR |
1.4912 (Approximate) |
| EN |
Similar to X12CrNiNb18-10H (Nearest Equivalent) |
Available Sizes
Outer Diameter (OD): 6 mm to 610 mm
Wall Thickness: 1.2 mm to 60 mm
Nominal Bore: 1/8” NB to 24” NB
Length: Single Random, Double Random, Custom Up to 12 Meters
ASTM A312 TP348H Chemical Composition
| Element |
Percentage (%) |
| Carbon (C) |
0.04 – 0.10 |
| Manganese (Mn) |
2.00 max |
| Silicon (Si) |
1.00 max |
| Chromium (Cr) |
17.0 – 19.0 |
| Nickel (Ni) |
9.0 – 13.0 |
| Phosphorus (P) |
0.045 max |
| Sulfur (S) |
0.030 max |
| Niobium (Nb/Cb) |
≥ 10 × C (%) |
| Nitrogen (N) |
0.10 max |
| Iron (Fe) |
Balance |
ASTM A312 TP348H Mechanical Properties
| Property |
Value |
| Tensile Strength |
≥ 515 MPa |
| Yield Strength (0.2% Proof) |
≥ 205 MPa |
| Elongation |
40% min |
| Hardness |
≤ 95 HRB |
| Modulus of Elasticity |
~193 GPa |
ASTM A312 TP348H Physical Properties
| Property |
Value |
| Density |
7.90 g/cm³ |
| Melting Point |
1398 – 1450°C |
| Thermal Conductivity |
16.3 W/m·K (at 100°C) |
| Electrical Resistivity |
0.78 µΩ·m |
| Coefficient of Expansion |
16.5 µm/m°C (20–100°C) |
Types of TP348H Stainless Steel Pipes
- Seamless Pipes
- Welded Pipes
- EFW Pipes
- Round Pipes
- Square Pipes
- Rectangular Pipes
- Heat Exchanger Pipes
- Boiler and Superheater Pipes
- Custom Fabricated Pipes
Applications
- High-temperature boiler systems
- Superheater and reheater tubes
- Petrochemical processing units
- Refinery pipelines and heaters
- Furnace and thermal processing equipment
- Heat exchangers and radiant tubes
- Chemical & fertilizer industry
- Power generation and steam lines
Reviews
There are no reviews yet.