Alloy 800HT (Welding),Incoloy 800HT Plate,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 Plate (UNS N08811)** --- ### **1.0 Product Overview** **Alloy 800HT Welding Plate** (commercially known as **Incoloy 800HT Welding Plate**, UNS **N08811**) is a premium nickel-iron-chromium superalloy plate product specifically 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 plate delivers superior performance at temperatures up to 815°C (1500°F). The plate form is ideal for fabrication into pressure vessels, heat treatment fixtures, and structural components in aggressive thermal environments where welding integrity is critical. --- ### **2.0 Chemical Composition (wt%)** | Element | Content (ASTM B409/ASME SB-409) | Role in Welding Applications | |---------|----------------------------------|-----------------------------| | **Nickel (Ni)** | 30.0–35.0 | Austenitic matrix stability, prevents hot cracking | | **Chromium (Cr)** | 19.0–23.0 | High-temperature oxidation resistance in HAZ | | **Iron (Fe)** | ≥39.5 | Base element, provides structural integrity | | **Carbon (C)** | 0.06–0.10 | Enhanced carbide strengthening for creep resistance | | **Aluminum (Al)** | 0.25–0.60 | Forms stable protective oxide scale, reduces oxidation | | **Titanium (Ti)** | 0.25–0.60 | Stabilization, prevents sensitization in HAZ | | **Manganese (Mn)** | ≤1.50 | Improves hot workability, aids in sulfur control | | **Silicon (Si)** | ≤1.00 | Enhances oxidation resistance, improves fluidity | | **Sulfur (S)** | ≤0.015 | Minimized to prevent hot cracking during welding | | **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 - **Impact Toughness:** 100 J min (Charpy V-notch at 21°C) **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) **Heat-Affected Zone (HAZ) Properties** - **Hardness:** 75–95 HRB - **Toughness:** Maintains base metal impact values - **Microstructure:** Stable, resistant to sensitization --- ### **5.0 International Standards** | Standard Type | Standard Number | Description | |--------------|----------------|-------------| | **UNS** | N08811 | Unified Numbering System | | **ASTM** | B409 | Nickel-Iron-Chromium Alloy Plate, Sheet, and Strip | | **ASME** | SB-409 | Boiler and Pressure Vessel Code | | **AWS** | A5.14 | ERNiCrFe-8 (Bare Welding Electrodes) | | **AWS** | A5.11 | ENiCrFe-8 (Covered Electrodes) | | **EN/DIN** | 1.4959 | X8NiCrAlTi32-21 | | **ISO** | 6207 | Nickel alloy wrought products | --- ### **6.0 Product Specifications** **Available Sizes & Dimensions** - **Thickness Range:** 5 mm to 150 mm (0.1875" to 6") - **Standard Widths:** 1000 mm, 1250 mm, 1500 mm, 2000 mm (39", 49", 59", 79") - **Standard Lengths:** 2000 mm, 2500 mm, 3000 mm, 6000 mm (79", 98", 118", 236") - **Custom Sizes:** Available for specific welding applications **Welding-Specific Tolerances** - **Thickness:** ±5% standard, ±3% for precision welding applications - **Flatness:** 3 mm per meter maximum for optimal fit-up - **Surface Condition:** Descaled and pickled for welding readiness - **Edge Preparation:** Mill edges suitable for welding preparation --- ### **7.0 Welding Applications** **Pressure Vessel Fabrication** - Head and shell welding - Nozzle-to-shell attachments - Manway and reinforcement pad welding - Support lug and attachment welding **Heat Exchanger Components** - Tubesheet welding - Channel and cover plate fabrication - Baffle and support plate attachment - Shell longitudinal and circumferential seams **Structural Welding Applications** - High-temperature support structures - Furnace component fabrication - Reactor internal attachments - Process vessel internals --- ### **8.0 Welding Characteristics & Procedures** **Recommended Welding Processes** - **SMAW (Shielded Metal Arc Welding):** ENiCrFe-8 electrodes - **GTAW (Gas Tungsten Arc Welding):** ERNiCrFe-8 filler metal - **GMAW (Gas Metal Arc Welding):** ERNiCrFe-8 wire - **SAW (Submerged Arc Welding):** With compatible flux **Welding Parameters** | Process | Current Type | Polarity | Preheat | Interpass Temp | |---------|--------------|----------|---------|----------------| | **SMAW** | DC | DCEP | None | ≤150°C | | **GTAW** | DC | DCEN | None | ≤150°C | | **GMAW** | DC | DCEP | None | ≤150°C | | **SAW** | DC | DCEP | None | ≤150°C | **Joint Preparation & Design** - **Edge Preparation:** Single V, double V, U-groove - **Root Gap:** 0–3 mm depending on thickness - **Included Angle:** 60–75 degrees for V-grooves - **Root Face:** 1.5–3.0 mm --- ### **9.0 Quality Assurance for Welding** **Material Certification** - Mill Test Certificate 3.1 per EN 10204 - Chemical analysis for each melt heat - Mechanical testing per heat treatment lot - Ultrasonic testing per ASTM A435/A577 **Welding Procedure Qualification** - **PQR Requirements:** Per ASME Section IX - **WPS Availability:** Standard procedures available - **NDT Methods:** RT, UT, PT, MT as required - **Hardness Testing:** Post-weld verification **Post-Weld Heat Treatment** - **Solution Annealing:** 1120–1170°C (2050–2140°F) - **Soak Time:** 1 hour per 25 mm thickness - **Cooling Method:** Rapid air or water quenching - **Documentation:** Complete thermal cycle records --- ### **10.0 Advantages for Welding Applications** - **Superior Weldability:** Excellent welding characteristics with minimal defects - **Stable HAZ:** Resists sensitization and maintains corrosion resistance - **Matched Strength:** Weld metal properties comparable to base metal - **High-Temperature Performance:** Maintains properties in welded condition up to 815°C - **Code Compliance:** Qualified for ASME Section VIII Division 1 and 2 applications --- ### **11.0 Storage & Handling** - Store in clean, dry conditions to prevent contamination - Protect edges and surfaces from mechanical damage - Maintain proper identification and heat number traceability - Store flat with adequate support to prevent distortion --- **Contact Information** For welding procedure specifications, technical support, or plate 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 1928 gallon liquid totes Special package is available on request.