Alloy 800HT (Welding),Incoloy 800HT Tube,N08811,E FORU

British Specs:BS 3072 BS 3073 BS 3074 BS 3075 BS 3076 NA15，American Specs:AMS 5766 Bar and Forgings AMS 5871 Sheet, Strip and Plate ASTM B408 ASTM B564 ASTM A240 ASTM A480，German Specs:WS 1.4876 WS 1.4958 WS 1.4959

**Technical Datasheet: Alloy 800HT / Incoloy 800HT Welding Tube (UNS N08811)** --- ### **1.0 Product Overview** **Alloy 800HT Welding Tube** (commercially known as **Incoloy 800HT Welding Tube**, UNS **N08811**) is a specialized tubular product engineered for high-temperature welding applications requiring exceptional creep rupture strength and oxidation resistance. With enhanced chemistry featuring controlled carbon content (0.06–0.10%) and elevated aluminum+titanium (Al + Ti ≥ 1.20%), this welding tube delivers superior performance in high-temperature service up to 815°C (1500°F). The product is specifically designed for welding applications in heat exchangers, boilers, and process heaters. --- ### **2.0 Chemical Composition (wt%)** | Element | Content (ASTM B163/ASME SB-163) | Role | |---------|----------------------------------|------| | **Nickel (Ni)** | 30.0–35.0 | Austenitic matrix stability, oxidation resistance | | **Chromium (Cr)** | 19.0–23.0 | High-temperature oxidation and sulfidation resistance | | **Iron (Fe)** | ≥39.5 | Base element | | **Carbon (C)** | 0.06–0.10 | Enhanced carbide strengthening for creep resistance | | **Aluminum (Al)** | 0.25–0.60 | Forms stable protective oxide scale | | **Titanium (Ti)** | 0.25–0.60 | Stabilization and precipitation strengthening | | **Manganese (Mn)** | ≤1.50 | Improves hot workability | | **Silicon (Si)** | ≤1.00 | Enhances oxidation resistance | | **Sulfur (S)** | ≤0.015 | Minimized to avoid hot shortness | | **Copper (Cu)** | ≤0.75 | — | *Critical Requirement: Aluminum + Titanium ≥ 1.20% for UNS N08811* --- ### **3.0 Physical Properties** | Property | Metric Value | Imperial Value | Condition | |----------|--------------|----------------|-----------| | **Density** | 8.03 g/cm³ | 0.29 lb/in³ | RT | | **Melting Range** | 1354–1384°C | 2470–2520°F | — | | **Specific Heat** | 460 J/kg·K | 0.11 Btu/lb·°F | 21°C | | **Thermal Conductivity** | 15.6 W/m·K | 9.0 Btu·in/hr·ft²·°F | 21°C | | **Thermal Expansion** | 16.6 × 10⁻⁶ /K | 9.2 × 10⁻⁶ /°F | 20–650°C | | **Electrical Resistivity** | 116 μΩ·cm | 45.8 μΩ·in | 21°C | | **Modulus of Elasticity** | 201 GPa | 29.1 × 10⁶ psi | RT | | **Magnetic Permeability** | <1.05 | <1.05 | Essentially non-magnetic | --- ### **4.0 Mechanical Properties** **Base Metal Properties (Solution Annealed)** - **Tensile Strength:** 450 MPa min (65 ksi min) - **Yield Strength (0.2% Offset):** 170 MPa min (25 ksi min) - **Elongation:** 30% min (in 2 inches) - **Hardness:** 70–90 HRB **Weld Metal Properties (with ERNiCrFe-8)** - **Tensile Strength:** 550–650 MPa (80–94 ksi) - **Yield Strength:** 300–400 MPa (44–58 ksi) - **Elongation:** 30–40% - **Impact Toughness:** 80–120 J (Charpy V-notch) --- ### **5.0 International Standards** | Standard Type | Standard Number | Description | |--------------|----------------|-------------| | **UNS** | N08811 | Unified Numbering System | | **ASTM** | B163 | Seamless Condenser and Heat-Exchanger Tubes | | **ASTM** | B407 | Seamless Pipe and Tube | | **ASME** | SB-163 | Boiler and Pressure Vessel Code | | **AWS** | A5.14 | ERNiCrFe-8 (Welding Electrode Specification) | | **TEMA** | Standards | Heat Exchanger Tube Specifications | --- ### **6.0 Product Specifications** **Tube Types Available** - **Seamless Tubes:** OD 3–100 mm (0.125–4 inches) - **Welded Tubes:** OD 15–120 mm (0.625–4.75 inches) - **Heat Exchanger Tubes:** per TEMA standards - **Boiler Tubes:** per ASME Section I **Welding-End Specifications** - **Square Cut Ends:** For tube-to-tubesheet welding - **Prepared Ends:** Machined for specific joint designs - **Surface Finish:** 0.8 μm Ra internal, 1.6 μm Ra external - **End Protection:** Plastic caps for contamination protection --- ### **7.0 Welding Applications & Procedures** **Primary Welding Processes** - **GTAW (TIG):** Tube-to-tubesheet and butt welds - **Orbital Welding:** Automated tube welding - **Laser Welding:** Precision tube joining **Recommended Welding Materials** - **Filler Metal:** ERNiCrFe-8 (AWS A5.14) - **Tungsten Electrode:** 2% Thoriated or Ceriated - **Shielding Gas:** Argon (99.995% purity) - **Backing Gas:** Argon for root protection **Welding Parameters for Tube Welding** | Tube OD (mm) | Wall Thickness (mm) | Current (A) | Gas Flow (l/min) | |--------------|---------------------|-------------|------------------| | 6–12 | 1.0–2.0 | 40–80 | 6–10 | | 12–25 | 1.5–3.0 | 60–120 | 8–12 | | 25–50 | 2.0–4.0 | 80–160 | 10–15 | --- ### **8.0 Applications** **Heat Exchanger Applications** - Shell and tube heat exchangers - Tube-to-tubesheet welds - U-bend tube welding - Heat exchanger bundle assembly **Boiler Applications** - Boiler tube welding - Superheater and reheater tubes - Water wall tube welding - Boiler tube repairs **Process Industry Applications** - Heater tube welding - Reactor coil welding - Transfer line exchangers - Process furnace tubes --- ### **9.0 Quality Assurance for Welding** **Material Certification** - Mill Test Certificate 3.1 per EN 10204 - Chemical analysis for each melt heat - Hydrostatic or pneumatic pressure testing - Eddy current or ultrasonic testing **Welding Procedure Qualification** - **Tube-to-Tubesheet Welding:** Per ASME Section IX - **Butt Welding Procedures:** Qualified for all positions - **NDT Requirements:** PT, RT, UT as specified - **Helium Leak Testing:** For critical applications **Dimensional Standards** - **OD & Wall Thickness:** per ASTM B163 - **Length Tolerances:** +3 mm, -0 mm for cut lengths - **Straightness:** 1 mm per meter maximum - **Surface Finish:** Special internal finishes available --- ### **10.0 Special Welding Considerations** **Tube-to-Tubesheet Welding** - **Joint Designs:** Protrusion, recessed, flush types - **Welding Techniques:** Manual, orbital, automated - **Quality Control:** Dye penetrant, helium leak testing - **Weld Sequence:** Multi-pass techniques **Tube Butt Welding** - **Joint Preparation:** Square butt, single V, double V - **Alignment:** Internal and external alignment tools - **Back Purging:** Essential for root pass quality - **Weld Progression:** Optimized for thin-wall tubing --- ### **11.0 Advantages for Welding Applications** - **Superior Weldability:** Excellent welding characteristics for tube applications - **Enhanced Creep Resistance:** Superior performance in high-temperature service - **Optimized Microstructure:** Resists sensitization and sigma phase formation - **Code Compliance:** Meets ASME, ASTM, and TEMA standards - **Proven Reliability:** Extensive use in critical heat exchanger applications --- ### **12.0 Storage & Handling for Welding** - Store in clean, dry conditions to prevent contamination - Protect tube ends with plastic caps - Maintain proper identification and heat number traceability - Store horizontally with adequate support to prevent bending --- **Contact Information** For welding procedure specifications, technical support, or tube product requirements, please contact our technical sales and engineering team.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1927 gallon liquid totes Special package is available on request.