316Ti Titanium-Stabilized Austenitic Stainless Steel Coil Tube for High-Temperature Corrosive Environments
Wenzhou Jixing Metal Materials Co., Ltd. presents its premium-grade 316Ti stainless steel coil tube, a titanium-stabilized austenitic alloy engineered to deliver superior resistance to intergranular corrosion and exceptional mechanical performance at elevated temperatures. As a direct and reliable replacement for 316L in service conditions ranging from 450 °C to 800 °C (842 °F to 1,472 °F) in chlorine-containing environments, this coil tube represents the optimal choice for demanding industrial applications where both corrosion resistance and high-temperature strength are critical.
Product Overview
The 316Ti coil tube belongs to the austenitic corrosion-resistant family of stainless steels, enhanced by the addition of titanium (Ti) as a carbide stabilizer. While conventional 316 and 316L grades rely on molybdenum content for pitting and crevice corrosion resistance, the 316Ti variant incorporates titanium to preferentially form titanium carbides, thereby preventing chromium carbide precipitation at grain boundaries during welding or heat exposure. This stabilization mechanism preserves the full corrosion resistance of the base alloy across the entire microstructure, making it particularly suitable for welded assemblies and components subjected to thermal cycling.
Delivered in coil form, these tubes offer significant advantages in terms of material utilization, continuous processing capability, and cost efficiency for high-volume manufacturing operations. The coil configuration enables seamless integration into automated forming, cutting, and fabrication lines, minimizing waste and maximizing throughput.
Material & Properties
The 316Ti alloy combines the inherent toughness and ductility of the austenitic microstructure with enhanced high-temperature performance. Titanium stabilization provides the following critical advantages over standard 316L:
- Superior Intergranular Corrosion Resistance: Titanium carbide formation eliminates chromium depletion at grain boundaries, maintaining full alloy composition throughout the microstructure even after exposure to temperatures between 450 °C and 800 °C (842 °F to 1,472 °F).
- Enhanced High-Temperature Strength: The 316Ti grade exhibits higher tensile and yield strength at elevated temperatures compared to 316L, owing to solid-solution strengthening effects of titanium.
- Excellent Pitting and Crevice Corrosion Resistance: The 2.0–2.5% molybdenum content provides robust protection against chloride-induced localized corrosion, making it suitable for marine, chemical, and process environments.
- Good Fabrication and Welding Characteristics: The austenitic structure retains full weldability, and titanium stabilization ensures that welded joints maintain corrosion resistance without requiring post-weld pickling or passivation in most service conditions.
- Non-Magnetic: The fully austenitic microstructure ensures non-magnetic behavior, beneficial for applications requiring electromagnetic compatibility.
- Wide Temperature Range: Suitable for continuous service from cryogenic temperatures up to 870 °C (1,598 °F) in non-oxidizing environments.
Specifications
| Parameter | Specification |
|---|---|
| Material Grade | 316Ti (UNS S31635 / EN 1.4571 / JIS SUS316Ti) |
| Product Form | Coil Tube (盘管) |
| Outer Diameter (OD) | 6.0 mm – 108 mm (0.24 in – 4.25 in) |
| Wall Thickness | 0.5 mm – 6.0 mm (0.020 in – 0.236 in) |
| Coil Inner Diameter | 200 mm – 600 mm (7.9 in – 23.6 in) |
| Coil Length per Roll | 500 m – 3,000 m (1,640 ft – 9,843 ft) |
| Chemical Composition (Max, wt%) | C ≤ 0.08 | Si ≤ 1.00 | Mn ≤ 2.00 | P ≤ 0.045 | S ≤ 0.030 |
| Chemical Composition (Min, wt%) | Cr 16.5–18.5 | Ni 10.0–14.0 | Mo 2.0–2.5 | Ti ≥ 5×C |
| Tensile Strength | ≥ 515 MPa (≥ 74.7 ksi) at 20 °C (68 °F) |
| Yield Strength (0.2% offset) | ≥ 205 MPa (≥ 29.7 ksi) at 20 °C (68 °F) |
| Elongation (50 mm gauge) | ≥ 40% |
| Hardness | ≤ 217 HB (Brinell) |
| Surface Finish | Bright Annealed (BA), Pickled & Passivated, or Custom |
| Surface Roughness (Ra) | ≤ 0.8 μm (32 μin) — BA finish; ≤ 1.6 μm (63 μin) — pickled |
| Dimensional Tolerance | OD: ±0.05 mm (±0.002 in) | Wall: ±0.05 mm (±0.002 in) | Straightness: ≤ 1.5 mm/m |
| Operating Temperature Range | -196 °C to 870 °C (-321 °F to 1,598 °F) |
| Recommended Heat Treatment | Stabilizing Anneal: 870–900 °C (1,598–1,652 °F), air or furnace cool |
| Standards Referenced | ASTM A213 / A269 | EN 10216-5 | ISO 13924 | GB/T 12771 |
Manufacturing Process
The production of 316Ti coil tube at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous multi-stage manufacturing sequence designed to ensure metallurgical integrity, dimensional precision, and surface quality:
- Raw Material Selection: High-purity 316Ti stainless steel billets are sourced from certified steel mills, with strict control of trace element content (particularly sulfur and nitrogen) to ensure optimal corrosion resistance and weldability.
- Hot Rolling & Pipe Forming: Billets are heated to 1,150–1,200 °C (2,092–2,192 °F) and hot-rolled into seamless pipe blanks, which are then precisely formed into the desired coil tube geometry using continuous rolling or pilger mill equipment.
- Cold Drawing & Sizing: The hot-rolled tube undergoes cold drawing through precision dies to achieve exact dimensional tolerances, improved surface finish, and enhanced mechanical properties through strain hardening.
- Stabilizing Annealing: Tubes are heat-treated at 870–900 °C (1,598–1,652 °F) with controlled cooling rates to promote full titanium carbide precipitation and eliminate residual stresses, ensuring the stabilized microstructure is achieved throughout the wall thickness.
- Pickling & Passivation: Surface oxide scales are removed via acid pickling (HNO₃/HF blend), followed by passivation treatment to form a protective chromium oxide film, ensuring optimal corrosion resistance from the point of delivery.
- Coiling & Packaging: Finished tubes are coiled to specified inner diameters using automated coiling equipment, with protective wrapping, moisture barriers, and secure strapping to prevent damage during transit.
- In-Line Quality Inspection: Every production lot undergoes ultrasonic flaw detection, dimensional measurement, spectrographic chemical analysis, and mechanical testing to verify conformance with specified standards.
Applications
The 316Ti coil tube is engineered for the most demanding service environments where simultaneous resistance to high temperatures, chloride attack, and intergranular corrosion is required. Key application sectors include:
- Chemical Processing Industry: Reactor tubes, heat exchanger coils, distillation column internals, and piping systems handling chlorinated compounds, hydrochloric acid, and mixed acid solutions at elevated temperatures (450–800 °C / 842–1,472 °F).
- Petrochemical & Oil Refining: Crude oil distillation units, fluid catalytic cracking (FCC) equipment, hydrogenation reactors, and sour water systems where H₂S and chloride exposure are prevalent.
- Marine & Offshore Engineering: Seawater cooling systems, ballast water treatment equipment, desalination plant tubing, and offshore platform structural components exposed to high-temperature salt spray environments.
- Power Generation: Boiler economizers, superheater tubes, and waste heat recovery systems in fossil fuel and nuclear power plants operating at sustained high temperatures.
- Food & Pharmaceutical Processing: Heat exchangers, pasteurization equipment, CIP (Clean-In-Place) systems, and hygienic tubing where both corrosion resistance and high-temperature sterilization are required.
- Environmental & Waste Treatment: Flue gas desulfurization (FGD) systems, landfill gas processing equipment, and incinerator heat recovery coils exposed to corrosive flue gases containing chlorides at temperatures up to 800 °C (1,472 °F).
- Automotive & Aerospace: Exhaust system components, turbocharger manifolds, and heat shield tubing requiring sustained high-temperature durability with corrosion resistance.
Quality Certifications
Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring that every coil tube product meets or exceeds international standards:
- ISO 9001:2015 — Quality Management System Certification, demonstrating consistent capability to provide products meeting customer and regulatory requirements.
- ISO 14001:2015 — Environmental Management System Certification, ensuring environmentally responsible manufacturing practices.
- ISO/IEC 17025 — Laboratory Competence for testing and calibration, supporting in-house material verification capabilities.
- EN 10204 3.1 — Manufacturer's Test Report certification for all production lots, providing traceable chemical composition, mechanical property, and dimensional data.
- ASTM/ASME — Compliance with applicable American Society for Testing and Materials and American Society of Mechanical Engineers standards for pressure vessel and piping applications.
- Mill Test Certificates (MTC) — Full traceability documentation including heat numbers, chemical analysis (spectrographic), mechanical test results, and dimensional inspection records for every coil delivered.
Unique Selling Points
316Ti Coil Tube — The Definitive Solution for High-Temperature Chloride Environments
- Direct 316L Replacement at 450–800 °C: Unlike 316L, which suffers from intergranular corrosion sensitivity above 450 °C due to chromium carbide precipitation, 316Ti maintains full corrosion resistance across the entire 450–800 °C (842–1,472 °F) range without any loss of grain boundary integrity.
- Higher High-Temperature Strength than 316L: Titanium solid-solution strengthening provides measurably superior tensile and yield strength at elevated temperatures, enabling thinner wall designs and reduced material weight in high-temperature applications.
- Welded Joint Reliability: The titanium stabilization ensures that welded assemblies retain full corrosion resistance without requiring extensive post-weld treatment, reducing fabrication complexity and cost.
- Coil Configuration for Maximum Efficiency: Continuous coil delivery eliminates butt-weld joints inherent to straight lengths, reducing leak points, improving pressure integrity, and enabling automated high-speed processing.
- Comprehensive Traceability: Full mill certification and heat-by-heat traceability ensure regulatory compliance for critical applications in oil & gas, nuclear, and pharmaceutical sectors.
For detailed quotations, custom specifications, or technical consultation regarding 316Ti coil tube applications, contact Wenzhou Jixing Metal Materials Co., Ltd. — your trusted partner in premium austenitic stainless steel tubing solutions.