Super304H/HR3C Seamless Stainless Steel Coil Tube for Ultra-Supercritical Boiler Superheaters
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd. presents a premium-grade seamless stainless steel coil tube specifically engineered for the most demanding service conditions in ultra-supercritical (USC) thermal power generation. Designed for integration into boiler superheater systems operating at steam temperatures of 600–620°C and pressures of 25–30 MPa, this coil tube represents the pinnacle of high-temperature alloy tubing technology for next-generation power plants.
Ultra-supercritical power cycles demand materials that can withstand sustained exposure to extreme thermal and mechanical stress while maintaining long-term structural integrity and resistance to oxidative degradation. Our Super304H and HR3C seamless coil tubes are purpose-developed to meet these rigorous requirements, delivering exceptional creep strength, superior oxidation resistance, and extended service life under the harshest conditions found in modern thermal power stations.
Material & Properties
The coil tubes are manufactured from two industry-leading high-temperature austenitic stainless steel alloys:
- Super304H – A low-carbon, high-purity variant of Type 304 stainless steel with enhanced creep strength and improved oxidation resistance at elevated temperatures. The reduced carbon content (≤0.030%) minimizes intergranular corrosion and carbide precipitation, while optimized alloying elements provide superior performance in ultra-supercritical environments.
- HR3C – A proprietary high-temperature alloy developed for extreme-temperature applications. HR3C offers outstanding creep rupture strength, exceptional resistance to scale formation, and superior resistance to sulfidation and carburization, making it ideal for the most severe superheater service conditions.
Both materials have undergone rigorous creep strength verification and oxidation resistance testing to confirm performance at the design operating conditions of 600–620°C and 25–30 MPa. These validated properties ensure reliable long-term operation with minimal degradation, reducing unplanned outages and extending the overall service life of the boiler system.
Specifications
| Parameter | Specification |
|---|---|
| Product Name | Seamless Stainless Steel Coil Tube |
| Material Grade | Super304H / HR3C |
| Tube Type | Seamless |
| Configuration | Coil (Helical / Spiral) |
| Application | Ultra-Supercritical Boiler Superheater |
| Steam Temperature | 600–620°C |
| Operating Pressure | 25–30 MPa |
| Key Performance | Creep Strength Verified / Oxidation Resistance Verified |
| Primary Industry | Thermal Power Generation |
| Weldability | Excellent (TIG / Pulse Arc Welding Compatible) |
| Surface Finish | Mill Finish / Pickled & Passivated (Available on Request) |
Manufacturing Process
Each coil tube is produced through a meticulously controlled manufacturing process to ensure consistent quality and dimensional accuracy:
- Raw Material Selection: High-purity Super304H or HR3C billets are sourced from certified steel mills, with strict chemical composition control to meet or exceed ASTM/EN specifications.
- Hot Piercing & Seamless Forming: Billets are heated and pierced using modern plug-rolling or Mannesmann processes to produce seamless tubes without welded seams, eliminating potential failure points.
- Hot Rolling & Cold Drawing: Tubes undergo precision hot rolling followed by cold drawing to achieve exact dimensional tolerances, superior surface finish, and enhanced mechanical properties.
- Solution Annealing: Tubes are solution-annealed at controlled temperatures to achieve optimal microstructure, relieve residual stresses, and ensure uniform mechanical performance.
- Coiling & Heat Treatment: Tubes are precisely coiled using CNC-controlled coiling equipment to maintain dimensional integrity. Post-coiling stress relief is performed as required.
- Quality Inspection: Every coil undergoes comprehensive non-destructive testing (NDT), including ultrasonic testing (UT), eddy current testing (ECT), and hydrostatic pressure testing, ensuring zero-defect delivery.
Applications
These seamless coil tubes are purpose-engineered for the following critical applications in the thermal power generation sector:
- Ultra-Supercritical (USC) Boiler Superheaters: Primary application in next-generation power plants operating at steam temperatures exceeding 600°C and pressures up to 30 MPa.
- Reheat Sections: Suitable for high-temperature reheat service where oxidation resistance and creep strength are paramount.
- High-Pressure Steam Lines: Can be deployed in auxiliary high-temperature steam piping systems within power station boiler houses.
- Power Plant Retrofits & Upgrades: Ideal for modernizing existing supercritical units to ultra-supercritical configurations, enhancing thermal efficiency and extending plant life.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains a rigorous quality management system and ensures full traceability for every product delivered:
- Material Compliance: Super304H and HR3C grades conform to recognized international standards including ASTM A213/A269, EN 10216-5, and relevant Chinese national standards (GB/T).
- Performance Verification: Creep rupture strength data and oxidation resistance test results are provided with each batch, confirming suitability for 600–620°C / 25–30 MPa service.
- Full Traceability: Each coil is accompanied by a complete mill test certificate (MTC) documenting chemical composition, mechanical properties, heat treatment records, and NDT results.
- Quality Management: Production processes adhere to ISO 9001 quality management system requirements, with additional adherence to power industry-specific quality protocols.
- Third-Party Inspection: Products are available for third-party inspection by organizations such as BV, SGS, or TUV upon customer request.
Key Selling Points
Proven for Ultra-Supercritical Service: Specifically engineered and validated for the extreme conditions of USC boiler superheaters at 600–620°C and 25–30 MPa.
Superior Creep & Oxidation Performance: Both Super304H and HR3C materials deliver exceptional creep strength and oxidation resistance, ensuring long service life and reduced maintenance intervals.
Seamless Construction: Eliminates welded joints, providing inherent strength, reliability, and resistance to failure under cyclic thermal stress.
Flexible Coil Configuration: Delivered in ready-to-install coil form, reducing field fabrication time, minimizing welds, and lowering overall installation costs.
End-to-End Quality Assurance: From raw material certification through final NDT, every step is documented and traceable, giving power plant operators complete confidence in product integrity.