Incoloy 800H Nickel-Iron-Chromium Alloy Coil Tube Heater

Product Overview

The Incoloy 800H Coil Tube Heater is a high-performance thermal transfer component manufactured by Wenzhou Jixing Metal Materials Co., Ltd. Engineered from Alloy 800H (UNS N08810), a nickel-iron-chromium austenitic alloy, this coil tube product is specifically designed for demanding high-temperature industrial heating applications. The coil tube heater facilitates efficient thermal energy transfer in processes requiring sustained elevated temperatures, exceptional resistance to thermal cycling, and superior resistance to carburization and oxidation. The product represents a critical component in industrial heat exchange systems where reliability and longevity under extreme operating conditions are paramount.

Material & Properties

Alloy 800H is a modified version of Incoloy 800, specifically developed for high-temperature service in the 800–1200°C (1472–2192°F) range. The alloy offers significantly improved resistance to intergranular corrosion compared to its predecessor, Incoloy 800, making it the preferred material for furnace applications and high-temperature heat exchangers.

Specifications

Parameter Specification
Material Grade Alloy 800H (UNS N08810 / ASTM B407)
Coil Tube Outer Diameter (OD) Ø6.35 mm – Ø50.8 mm (1/4" – 2")
Wall Thickness 0.50 mm – 3.00 mm (0.020" – 0.118")
Coil Pitch (Center-to-Center Spacing) 10 mm – 50 mm (configurable per application)
Coil Diameter (Bundling Diameter) 100 mm – 800 mm (customizable)
Tube Length per Coil 3 m – 12 m (standard); up to 25 m (special order)
Surface Finish Pickled & Passivated; optionally polished to 2B finish
Forming Method Cold coil winding with controlled strain distribution
Heat Treatment Solution annealed at 1120–1150°C, water quench
End Connection Types Flanged, threaded (NPT/BSP), welded (butt/TIG), or socket-weld
Maximum Design Pressure Up to 6.0 MPa (870 psi) at operating temperature
Standards Compliance ASTM B407, ASME BPV Section II, EN 10216, GB/T 24511

Manufacturing Process

The production of Incoloy 800H coil tube heaters at Wenzhou Jixing Metal Materials Co., Ltd. follows a rigorous multi-stage manufacturing protocol designed to ensure dimensional accuracy, metallurgical integrity, and long-term operational reliability.

  1. Raw Material Procurement & Inspection: Alloy 800H seamless tubes are sourced from certified suppliers conforming to ASTM B407 specifications. Incoming material undergoes spectroscopic analysis (OES/PMI) to verify chemical composition, along with hydrostatic pressure testing and visual inspection for surface defects.
  2. Dimensional Preparation & End Finishing: Tubes are cut to precise lengths using CNC cutting systems to achieve tolerances within ±0.5 mm. End faces are machined flat and deburred to prepare for subsequent forming and connection operations.
  3. Coil Winding & Forming: Tubes are wound into the specified coil geometry using precision CNC coil winding machinery. The forming process employs controlled bending radii (minimum bend radius of 3× OD) to prevent wall thinning, ovality distortion, and stress concentration. Multi-axis forming ensures uniform strain distribution throughout the coil geometry.
  4. Fixturing & Dimensional Stabilization: Formed coils are secured in custom fixtures to maintain geometric accuracy. Spacers and support structures are installed at design-interval positions to prevent deformation during subsequent processing and installation.
  5. Welding & Assembly: TIG (Tungsten Inert Gas) welding is performed for all joints, utilizing argon shielding gas to prevent oxidation. Welding parameters are optimized for Alloy 800H to ensure full penetration, minimize heat-affected zone (HAZ) sensitization, and maintain mechanical properties. All welds are inspected per ASME Section IX qualification procedures.
  6. Post-Weld Heat Treatment (PWHT): Where required by design specifications, coils undergo post-weld solution annealing at 1120–1150°C followed by rapid water quenching. This process restores full solution-treated microstructure, relieves residual stresses, and ensures corrosion resistance equivalent to the base material.
  7. Pickling & Passivation: Completed assemblies are cleaned using a controlled acid pickling process (nitric-hydrofluoric acid blend) to remove oxide scale and weld discoloration. Subsequent passivation with nitric acid or citric acid establishes a stable chromium oxide passive film on the surface.
  8. Final Quality Assurance & Testing: Comprehensive final inspection includes dimensional verification (CMM or laser measurement), visual examination per ASME Section V, and optional non-destructive testing (dye penetrant, magnetic particle, or radiographic testing) of weld joints. Hydrostatic pressure testing is conducted at 1.5× design pressure to validate structural integrity.

Applications

Incoloy 800H Coil Tube Heaters are deployed across a broad spectrum of high-temperature industrial processes where conventional stainless steels are inadequate. Key application areas include:

Quality Certifications

Wenzhou Jixing Metal Materials Co., Ltd. maintains a comprehensive quality management framework ensuring conformance to international standards:

Unique Selling Points