Seamless Stainless Steel TP347 Tube (UNS S34700)
Niobium-Stabilized Austenitic Stainless Steel for High-Temperature & Corrosion-Resistant Service
1. What is a Seamless TP347 Stainless Steel Tube?
Seamless TP347 stainless steel tube (UNS S34700 / W.Nr. 1.4550) is a niobium (columbium) stabilized austenitic stainless steel tube designed for applications involving high temperatures and intergranular corrosion resistance.
Manufactured through a seamless process (hot piercing + cold drawing/finishing) from a solid billet, TP347 tubes provide:
- Uniform metallurgical structure
- Excellent pressure resistance
- No weld seam defects or weld decay risk
The key feature of TP347 is the addition of Niobium (Nb), which stabilizes carbon and prevents chromium carbide precipitation at grain boundaries. This ensures superior resistance to sensitization and intergranular corrosion (IGC), even after prolonged exposure to elevated temperatures or welding.
2. Key Features & Technical Advantages
Excellent Intergranular Corrosion Resistance
Niobium stabilization prevents carbide precipitation, eliminating sensitization in the heat-affected zone (HAZ).
High-Temperature Performance (Up to 815°C)
Performs reliably in continuous service up to 815°C (1500°F) with strong oxidation and scaling resistance.
Improved Creep Strength
Compared with standard 304/304L, TP347 offers better creep resistance and structural stability under long-term high-temperature stress.
Excellent Weldability
Can be welded using standard methods without requiring post-weld heat treatment to restore corrosion resistance.
High Pressure Integrity
Seamless manufacturing ensures compliance with ASTM A213 / ASME SA213 / EN 10216-5, suitable for critical pressure systems.
Product Specifications and Data
To provide a comprehensive overview of this high-performance material, here are the detailed technical specifications and performance data for Stainless Steel 347.
The composition of Stainless Steel 347 is carefully balanced to achieve its superior high-temperature stability and corrosion resistance.
Stainless Steel 347 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.
Common Industrial Applications
Seamless TP347 stainless steel tubes are widely used in high-temperature and cyclic thermal environments, including:
Power Generation
- Superheater tubes
- Reheater tubes
- Boiler headers
Aerospace & Energy Systems
- Exhaust manifolds
- Jet engine components
- High-temperature ducts
Petrochemical & Refinery
- Heat exchanger tubes
- Catalytic cracking units
- Process piping systems
Waste & Incineration
- Furnace components
- Combustion chambers
- High-temperature flue gas systems
Advanced Manufacturing Process
- Raw Material Selection & Billet Heating
Controlled heating to achieve optimal grain structure. - Rotary Piercing
Formation of hollow shell without internal defects. - Cold Drawing / Cold Rolling
Achieves precise dimensions and superior surface finish. - Solution Annealing
Heat treatment to restore corrosion resistance and mechanical properties. - Full Non-Destructive Testing (NDT)
- Ultrasonic Testing (UT)
- Eddy Current Testing (ET)
- Hydrostatic Testing
100% Quality Assurance & Certification
We ensure full compliance with international quality standards:
- Material Certificates: EN 10204 3.1 / 3.2
- Traceability: Full heat number traceability
- Chemical & Mechanical Testing: PMI, hardness, tensile, flattening, flaring
- Corrosion Testing: Intergranular Corrosion (IGC) per ASTM A262
- Third-Party Inspection: ABS, TÜV, BV, DNV, SGS
