High-Purity Stainless Steel Coil Tube with Advanced Residual Element Control
Product Overview
Wenzhou Jixing Metal Materials Co., Ltd presents its premium-grade stainless steel coil tube, engineered with industry-leading residual element control to deliver exceptional metallurgical purity. This coiled stainless steel tubing is specifically formulated for demanding applications where trace element contamination can compromise structural integrity, thermal performance, or corrosion resistance. By rigorously limiting the content of phosphorus (P), sulfur (S), boron (B), and lead (Pb), this product eliminates the risk of hot shortness and hot brittleness during downstream hot-rolling, forging, and welding operations, ensuring superior formability and long-term reliability.
The coil tube is supplied in continuous coil form, offering significant material utilization advantages over straight-length seamless tubes. This format reduces waste during cutting and fabrication while enabling high-throughput processing in automated tube-forming lines, making it an ideal feedstock for heat exchangers, process piping, and precision-engineered components.
Unique Selling Points
- Ultra-Low Sulfur Control: Sulfur content maintained below 0.005%, far exceeding standard commercial-grade specifications, effectively preventing manganese sulfide (MnS) inclusion formation that causes hot shortness during elevated-temperature processing.
- Phosphorus Limitation: Phosphorus restricted to below 0.020%, mitigating the risk of hot brittleness and ensuring uniform grain structure during hot working operations.
- Comprehensive Trace Element Management: Boron and lead concentrations are tightly controlled to prevent embrittlement, intergranular degradation, and galvanic incompatibility in multi-material assemblies.
- Full Traceability: Every coil batch is accompanied by mill test certificates with spectroscopic analysis data, providing complete chemical composition traceability from raw material to finished product.
- Coil Format Efficiency: Continuous coil supply minimizes butt-weld joints, reduces material waste, and accelerates fabrication throughput for high-volume production environments.
Material & Properties
The stainless steel coil tube is manufactured from austenitic stainless steel grades, with metallurgical specifications optimized for high-purity performance. The austenitic microstructure provides excellent ductility, weldability, and corrosion resistance across a wide temperature range. The controlled residual element chemistry ensures a clean, inclusion-free matrix that supports superior mechanical properties and surface finish quality.
Key Metallurgical Characteristics
- Microstructure: Fully austenitic with controlled grain size, free from deleterious non-metallic inclusions
- Hot Workability: Enhanced by low S and P levels, enabling reliable hot-rolling, hot-forming, and hot-extrusion without cracking or segregation
- Weldability: Low trace element content minimizes hot cracking susceptibility in both fusion and solid-state welding processes
- Corrosion Resistance: Clean matrix with minimal sulfide and oxide inclusions preserves the protective chromium oxide passive film integrity
- Mechanical Properties: Uniform tensile strength, yield strength, and elongation achieved through homogeneous chemical composition
Specifications
| Parameter | Specification | Notes |
|---|---|---|
| Product Type | Stainless Steel Coil Tube | Continuous coil format |
| Material Grades | 304L, 316L, 321, 347, Custom Grades | Austenitic stainless steel |
| Sulfur (S) | ≤ 0.005% | Critical for preventing hot shortness |
| Phosphorus (P) | ≤ 0.020% | Prevents hot brittleness |
| Boron (B) | ≤ 0.001% (unless specified) | Prevents embrittlement |
| Lead (Pb) | ≤ 0.005% | Prevents galvanic issues |
| Carbon (C) | ≤ 0.030% (L grades) | Enhanced corrosion resistance |
| Outer Diameter Range | 3.0 – 168.0 mm (0.12 – 6.61 in) | Custom diameters available |
| Wall Thickness Range | 0.25 – 6.0 mm (0.010 – 0.236 in) | Precision tolerance available |
| Coil Inner Diameter | 500 – 600 mm (19.7 – 23.6 in) | Standard packaging |
| Coil Outer Diameter | Up to 1,500 mm (59.1 in) | Adjustable per customer requirement |
| Surface Finish | 2B, BA, No. 4, Mirror (as requested) | Industrial to cosmetic grades |
| Tensile Strength | ≥ 520 MPa (≥ 75,400 psi) | Typical for annealed austenitic grades |
| Yield Strength | ≥ 205 MPa (≥ 29,700 psi) | At 0.2% offset |
| Elongation | ≥ 40% | At break |
| Operating Temperature | −196 °C to +870 °C (−321 °F to +1,598 °F) | Grade-dependent |
Manufacturing Process
The production of high-purity stainless steel coil tube at Wenzhou Jixing Metal Materials Co., Ltd follows a rigorously controlled multi-stage process to ensure exceptional metallurgical quality and dimensional accuracy.
- Raw Material Selection & Sourcing: Only certified virgin steel billets and slabs from approved suppliers are accepted. Incoming materials undergo full spectroscopic chemical analysis to verify compliance with the ultra-low residual element specifications (S ≤ 0.005%, P ≤ 0.020%, B and Pb within limits).
- Secondary Refining & Degassing: Steel melts are processed through vacuum degassing (VD) and/or argon oxygen decarburization (AOD) to achieve ultra-low sulfur and phosphorus levels. Inclusion control technologies such as ladle refining and continuous casting with electromagnetic stirring ensure a clean, homogeneous melt.
- Continuous Casting: Purified steel is cast into precise-dimension slabs or billets using controlled cooling rates to achieve the target austenitic grain structure with minimal segregation.
- Hot Rolling & Hot Forming: The low S and P chemistry ensures the material remains ductile and crack-free during hot rolling and hot tube forming operations. Hot workability is maintained across the full processing temperature range without hot shortness or hot brittleness.
- Pipe Making (Plug Rolling or Mannesmann Piercing): Billets are pierced and rolled into seamless tube blanks. The clean metallurgical quality ensures uniform wall thickness and minimal defects during the forming process.
- Cold Drawing & Sizing: Tubes are cold-drawn to precise final dimensions with tight tolerances on outer diameter and wall thickness. The controlled chemistry supports excellent cold formability without cracking.
- Heat Treatment (Annealing & Pickling): Solution annealing in a controlled atmosphere furnace restores full austenitic structure and optimal mechanical properties. Subsequent acid pickling and passivation remove surface scale and establish a stable chromium oxide passive layer.
- Coiling & Packaging: Finished tubes are wound onto standard or custom-diameter cores, wrapped with protective film or paper, and strapped for shipment. Each coil is labeled with batch identification and accompanied by a full mill test certificate.
- Final Quality Inspection: Every coil undergoes 100% dimensional inspection, surface quality verification, and periodic chemical re-analysis to confirm residual element compliance. Non-destructive testing (eddy current, ultrasonic) is performed to detect any internal or surface defects.
Applications
The high-purity stainless steel coil tube is designed for the most demanding industrial applications where material integrity and process reliability are paramount.
- Heat Exchangers & Boilers: Ultra-low sulfur content prevents hot cracking during tube bending and welding, ensuring leak-free performance in high-temperature heat exchange systems used in power generation, petrochemical, and HVAC industries.
- Process Piping Systems: Used in chemical processing, pharmaceutical manufacturing, and food and beverage industries where corrosion resistance and sanitary-grade surface finish are critical. The controlled residual element chemistry prevents intergranular corrosion and stress corrosion cracking.
- Oil & Gas Industry: Deployed in upstream and downstream processing facilities, including subsea pipelines, wellhead assemblies, and refinery heat exchangers, where resistance to sulfide stress cracking and high-temperature service is essential.
- Nuclear & Aerospace: High-purity grades meet the stringent material qualification requirements for nuclear reactor coolant loops, aerospace engine components, and cryogenic systems where trace element contamination is unacceptable.
- Medical & Pharmaceutical Equipment: Sanitary-grade coil tube used for manufacturing medical device tubing, pharmaceutical process lines, and laboratory instrumentation requiring biocompatibility and ease of sterilization.
- Food & Dairy Processing: Hygienic coil tube for milk processing, brewing, and food packaging equipment, meeting FDA and EHEDG standards for food-contact materials.
- Automotive & Transportation: Used in exhaust system components, fuel cell assemblies, and structural tubing where high-temperature strength and corrosion resistance are required.
- Downstream Tube Manufacturing: Serves as premium feedstock for secondary processors manufacturing precision tubing, capillary tubes, and specialized alloy products requiring clean chemistry.
Quality Certifications & Standards Compliance
Wenzhou Jixing Metal Materials Co., Ltd maintains a comprehensive quality management system and adheres to internationally recognized standards to ensure every coil tube batch meets the highest quality benchmarks.
- ISO 9001:2015: Certified Quality Management System covering all aspects of production, inspection, and traceability.
- ISO 3834: Quality requirements for welding of metallic materials, ensuring weld integrity in fabricated assemblies.
- EN 10204 3.1: Third-party inspection certificates available upon request, providing independent verification of chemical composition and mechanical properties.
- ASTM / ASME Standards: Products manufactured to ASTM A213, A269, A312, A511, and ASME SA-213, SA-269, SA-312 specifications.
- European Standards: Compliance with EN 10216-5, EN 10217-7, and EN 10297 for seamless stainless steel tubes.
- Mill Test Certificates (MTC): Every shipment includes a full MTC documenting chemical analysis (including trace element data for S, P, B, and Pb), mechanical test results, heat treatment parameters, and dimensional inspection records.
- Material Traceability: Complete batch-to-batch traceability from raw material heat number through all processing stages to the finished coil, enabling full recall and quality investigation capability.
Why Choose Wenzhou Jixing Metal Materials Co., Ltd? Our high-purity stainless steel coil tube represents the pinnacle of metallurgical control in the industry. By enforcing residual element limits that are significantly more stringent than standard commercial specifications—particularly sulfur below 0.005% and phosphorus below 0.020%—we deliver a product that eliminates hot shortness and hot brittleness risks at every stage of downstream processing. Combined with our coil format efficiency, full traceability, and adherence to global quality standards, our coil tube provides engineering teams with a reliable, high-performance material solution for the world's most critical applications.