What is TP321H Seamless Stainless Steel Tube?
SeamlessTP321H stainless steel tube (UNS S32109 / W.Nr. 1.4878) is a titanium-stabilized, high-carbon austenitic stainless steel designed for elevated temperature and high-stress applications.
Manufactured through a seamless process (hot piercing + precision cold finishing), it provides:
- Uniform microstructure
- No weld seam defects
- Excellent high-pressure integrity
- Superior resistance to thermal cycling
“321H” Grade Characteristics
- Carbon content: 0.04% – 0.10% (controlled high carbon)
- Titanium (Ti) stabilized
Titanium binds with carbon to form TiC (titanium carbides), preventing:
- Chromium carbide precipitation
- Intergranular corrosion (IGC)
- Sensitization during welding and heat exposure
Ideal for service temperatures in the range of:
427°C – 816°C (800°F – 1500°F)
2. Key Features & Technical Advantages
Superior Creep & Stress Rupture Strength
- Higher carbon content improves high-temperature mechanical stability
- Excellent resistance to long-term stress and deformation
Titanium Stabilization (IGC Resistance)
- Prevents sensitization in the carbide precipitation temperature range
- Excellent resistance to intergranular corrosion (IGC)
- No post-weld heat treatment required
High-Temperature Oxidation Resistance
- Comparable oxidation resistance to TP304/304L
- Stable scaling resistance up to ~816°C continuous service
High Pressure & Structural Integrity
- Seamless construction eliminates weld defects
- Conforms to:
- ASTM A213
- EN 10216-5
Excellent Fabricability
- Good ductility and toughness
- Easily welded and cold formed
- Suitable for complex fabrication requirements
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Super Duplex Steel UNS S32760.
Stainless Steel 321H is specifically designed to maintain its strength and shape in high-temperature, high-stress environments.
These physical properties highlight the material’s ability to perform reliably under a wide range of conditions.
The Standard of ASTM A789 Size Tolerance Size Chart :
5. Dimensional Standards & Tolerances
Manufactured to strict international standards:
Applicable Standards
- ASTM A213
- EN 10216-5 (D3/D4)
- ASTM A269
Typical Tolerances
- OD tolerance: ±0.10 mm to ±0.5%
- Wall thickness: ±7.5% to ±20%
- Length: per standard or customized
Ensureshigh precision for heat exchanger and pressure systems
6. Industrial Applications
TP321H seamless tubes are widely used in high-temperature and corrosion-resistant environments:
Power Generation
- Superheater tubes
- Reheater tubes
- Boiler components
Petrochemical Industry
- Furnace components
- Thermal reactors
- Expansion joints
Aerospace Industry
- Exhaust systems
- Engine components
- High-temperature liners
Heat Treatment & Furnace
- Retorts
- Muffles
- Furnace fixtures
Waste Incineration
- Combustion chambers
- Pollution control systems
Quality Assurance & Inspection
Each TP321H tube is strictly controlled and fully traceable:
Certification
- EN 10204 3.1 / 3.2 Material Test Certificates (MTC)
Testing & Inspection
- 100% PMI (Positive Material Identification)
- Ultrasonic Testing (UT)
- Eddy Current Testing (ET)
- Hydrostatic Testing
Advanced Metallurgical Testing
- Intergranular Corrosion (IGC) Test (ASTM A262 Practice E)
- Grain size analysis (ASTM E112)
Third-Party Inspection
- ABS
- DNV
- BV (Bureau Veritas)
- TÜV
- SGS
