Tungsten Carbide Coated Stainless Steel Coil Tube
Product Code: 319 | Manufacturer: Wenzhou Jixing Metal Materials Co., Ltd.
Product Overview
The Tungsten Carbide (WC) Coated Stainless Steel Coil Tube is an advanced wear-resistant tubing product engineered for extreme service environments where conventional stainless steel coil tubes suffer premature degradation. This product combines the corrosion resistance and ductility of austenitic stainless steel with the exceptional hardness and abrasion resistance of tungsten carbide coating, delivering a synergistic material system that significantly extends operational life in high-wear applications.
Coil tube (Coiltube), also known as continuous coil tubing, is supplied in a helical coil configuration to facilitate automated processing, reduce material waste, and minimize handling labor. The coil form factor enables seamless integration into high-volume manufacturing lines for heat exchangers, chemical processing equipment, and industrial piping systems.
Material & Properties
Base Material
- Substrate: Austenitic Stainless Steel (304, 316L, 321, or 310S depending on application requirements)
- Corrosion Resistance: Superior resistance to pitting, crevice corrosion, and general oxidation in acidic, alkaline, and chloride-containing environments
- Mechanical Properties: Tensile strength of 515–720 MPa; elongation ≥ 35% (as per ASTM A269)
- Temperature Range: Operational from −196°C to +870°C (base material dependent)
Coating System
- Coating Material: Tungsten Carbide (WC) with Cobalt (Co) binder — typically WC-Co composite (60–90% WC by weight)
- Coating Hardness: 1400–1600 HV (Vickers Hardness), equivalent to Rockwell C 78–82
- Coating Thickness: 0.1–0.5 mm (controllable per application requirement)
- Adhesion Strength: ≥ 25 MPa (per ASTM B571 / ISO 2360)
- Abrasion Resistance: 5–10× improvement over uncoated 316L stainless steel in sliding wear tests
- Wear Life: Predicted service life extension of 3–8× relative to bare stainless steel coil tubes in abrasive slurry conditions
Specifications
| Parameter | Specification | Standard / Test Method |
|---|---|---|
| Outer Diameter (OD) | Φ 6.0 – Φ 168.3 mm | ASTM A269 / GB/T 14976 |
| Wall Thickness (WT) | 0.5 – 12.0 mm | ASTM A269 |
| Coil Length | 20 – 500 m per coil (custom available) | Manufacturer Specification |
| Coil Core Diameter | Φ 300 – Φ 600 mm | Manufacturer Specification |
| Surface Finish | BA (Bright Annealed) / Pickled / Coated surface Ra ≤ 1.6 μm | ASTM A213 |
| Tolerance (OD) | ±0.10 mm (precision grade); ±0.25 mm (commercial grade) | ASTM A269 |
| Tolerance (WT) | ±10% of nominal | ASTM A269 |
| Coating Hardness | 1400–1600 HV | ISO 6507 (Vickers) |
| Coating Thickness | 0.1–0.5 mm (adjustable) | ISO 2360 |
| Adhesion | ≥ 25 MPa | ASTM B571 |
| Heat Treatment | Solution annealing at 1040–1120°C followed by water quench | ASTM A269 |
| Delivery Condition | Annealed and pickled / Coated and stabilized | Per customer requirement |
| Applicable Standards | ASTM A269, ASTM A213, ASME B36.19M, GB/T 14976, EN 10216-5 | — |
Manufacturing Process
- Raw Material Selection & Inspection: High-purity stainless steel billets are sourced from certified suppliers. Incoming material undergoes spectroscopic analysis (OES) to verify chemical composition within ASTM/EN tolerances.
- Hot Rolling & Piercing: Billets are reheated to 1150–1250°C and hot-rolled through a continuous mill to produce seamless coil tube blanks with tight dimensional control.
- Hot Isostatic Pressing (HIP) — Optional: For critical applications, the tube undergoes HIP treatment at 1100°C and 100–150 MPa to eliminate internal porosity and enhance substrate integrity.
- Surface Preparation: The coil tube surface is mechanically cleaned via abrasive blasting (Al₂O₃ grit, 50–80 mesh) to achieve a surface roughness of Ra 3.2–6.3 μm, ensuring optimal coating adhesion.
- Tungsten Carbide Coating Application:
- Thermal Spray (HVOF — High Velocity Oxygen Fuel): WC-Co composite powder is sprayed at velocities of 500–700 m/s, depositing dense, low-porosity coating layers with minimal thermal distortion.
- Alternative: Plasma Spraying or Electrostatic Powder Coating + Sintering methods are available depending on coating thickness requirements.
- Post-Coating Heat Treatment: The coated tube is sintered at 1150–1200°C under vacuum or inert atmosphere (Ar/N₂) for 2–6 hours to densify the coating, reduce porosity to <1%, and strengthen the metallurgical bond between the WC-Co layer and the stainless steel substrate.
- Dimensional Stabilization & Annealing: A final solution anneal is performed to relieve residual stresses introduced during coating and sintering, ensuring dimensional stability during subsequent forming operations.
- Quality Inspection: Non-destructive testing (NDT) including ultrasonic thickness measurement, magnetic particle inspection (MPI), and hardness profiling across the coating cross-section. Coating adhesion is verified via scratch testing or tensile adhesion coupons.
- Coiling & Packaging: The finished coil tube is wound onto a protective core, wrapped with anti-corrosion film, and palletized for shipment.
Applications
- Chemical Processing: Reactor internals, heat exchanger tubes, and piping in environments with abrasive slurries and corrosive media (e.g., phosphoric acid production, titanium dioxide manufacturing).
- Mineral Processing & Mining: Slurry transport lines, pump casings, and grinding mill liners where high-abrasion particulate flow causes rapid wear of conventional tubing.
- Pulp & Paper Industry: Piping systems handling abrasive fiber suspensions and acidic cooking liquors.
- Oil & Gas: Downhole tubing, sand production control equipment, and subsea flow lines exposed to erosive multiphase flow.
- Power Generation: Boiler tubes and superheater elements in coal-fired and biomass plants where fly ash erosion is a critical failure mode.
- Food & Pharmaceutical: Hygienic-grade tubing in applications requiring both corrosion resistance and extended wear life in high-shear processing equipment.
- Automotive & Aerospace: Exhaust system components, turbocharger housings, and fuel system tubing requiring elevated wear resistance at elevated temperatures.
Quality Certifications & Compliance
- ISO 9001:2015 — Quality Management System certification for manufacturing and supply chain processes
- ISO 14001:2015 — Environmental Management System, ensuring sustainable manufacturing practices
- EN 10204 3.1 — Mill test certificates with third-party inspection (TPI) available upon request
- API 5L / API 5CT — Compliance for oil and gas sector applications
- CE Marking — Conformity with European Union directives for pressure equipment (PED 2014/68/EU)
- NORSOK M-650 — For subsea and offshore applications in Nordic markets
- Material Traceability: Full heat-number traceability from raw material through final coating and inspection, with digital documentation provided per coil
Unique Selling Points
1. Extended Service Life: Life prediction models based on Archard wear equation and Miner's cumulative damage rule demonstrate a 3–8× service life improvement over uncoated stainless steel in equivalent operating conditions, reducing unplanned downtime and replacement costs.
2. Dual-Function Material System: The combination of stainless steel substrate (corrosion resistance) and WC-Co coating (abrasion resistance) eliminates the need for multiple material grades in a single system, simplifying inventory and maintenance.
3. Coil Form Factor Advantage: Continuous coil delivery minimizes butt welds, reduces material waste by up to 20% compared to cut-length supply, and enables automated cut-to-length processing for downstream fabrication.
4. Customizable Coating Parameters: Coating thickness, hardness, and WC/Co ratio can be tailored to specific wear-corrosion synergy requirements, offering a platform solution for diverse industrial challenges.
5. Predictive Maintenance Compatibility: Integrated life prediction methodology enables condition-based maintenance scheduling, transitioning from reactive to proactive asset management strategies.
Technical Note
The preparation and life prediction methodology for tungsten carbide coated coil tubes follows a rigorous approach combining experimental characterization with computational modeling. Wear life prediction employs finite element analysis (FEA) coupled with empirical wear models (Archard, Rabinowicz) calibrated against pin-on-disk tribometer data. The coating degradation mechanism is modeled as a multi-stage process encompassing adhesion wear, abrasive wear, and coating spallation, with each stage contributing to the cumulative damage function. This predictive framework enables reliable estimation of remaining useful life (RUL) under defined operating parameters, supporting optimized maintenance intervals and total cost of ownership (TCO) reduction.