As a modification of Incoloy 800, the "HT" designation signifies a Aluminum, Titanium, and Carbon combined with a high-temperature anneal. This results in optimum creep-rupture strength.
This specification sheet outlines the technical parameters, chemical composition, and dimensional standards for our Incoloy 800HT flanges. These components are engineered for applications exceeding 600°C, such as petrochemical furnace crackers, steam methane reformers, and superheater tubing.
Incoloy 800HT Material Standards
Our manufacturing process strictly adheres to international standards to ensure compatibility and safety in high-pressure, high-temperature systems.
Material Specification: ASTM B564 / ASME SB564 (Nickel Alloy Forgings)
Dimensional Standard: ASME B16.5 (1/2" – 24") / ASME B16.47 (26" – 60")
Grade: UNS N08811 (Incoloy 800HT)
Incoloy 800HT Specifications and Chemical Composition
Incoloy 800HT is part of the 800 series of alloys, optimized for high-temperature service. The "HT" designation indicates higher temperature capability, achieved through strict compositional control and processing.
Chemical Composition
The precise balance of elements is critical to its performance. The standard composition range is as follows:
Nickel (Ni): 30.0 - 35.0%
Chromium (Cr): 19.0 - 23.0%
Iron (Fe): ≥ 39.5%
Carbon (C): 0.06 - 0.10%
Aluminum (Al): 0.15 - 0.60%
Titanium (Ti): 0.15 - 0.60%
Manganese (Mn): ≤ 1.50%
Silicon (Si): ≤ 1.00%
Copper (Cu): ≤ 0.75%
Sulfur (S): ≤ 0.015%
Note: A combined (Al+Ti) content of 0.85 - 1.20% is required.
Incoloy 800HT Equivalents
The alloy is recognized under multiple international standards systems:
Werkstoff Nr.: 1.4959 / 1.4876
GOST: ЭИ670
EN: X8NiCrAlTi32-21
JIS: NCF 800HT
BS: NA 15(HT)
Incoloy 800HT Mechanical and Physical Properties
Room Temperature Properties (Annealed Condition)
Tensile Strength: ≥ 520 MPa (75,000 psi)
Yield Strength (0.2% Offset): ≥ 205 MPa (30,000 psi)
Elongation: ≥ 30%
Density: 7.94 g/cm³
Elevated Temperature Strength (Creep-Rupture)
Incoloy 800HT's primary advantage is its retained strength at high temperatures. For example, at 760°C (1400°F), its typical stress to rupture in 1000 hours is 70 MPa.
Physical Properties
Melting Range: 1357 - 1385°C
Thermal Expansion: 14.4 µm/m·°C (20-100°C)
Thermal Conductivity: 11.5 W/m·°C
ASME B16.5 Class 150 Incoloy 800HT Flange Dimension
Dimensions follow ASME B16.5 for precise fitment. Below is a table for Class 150 weld neck flanges; contact us for other classes or custom sizes.
|
NPS (in) |
OD (in) |
Thickness Min. (in) |
RF Dia. (in) |
Bolt Holes (No.) |
Bolt Hole Dia. (in) |
Bolt Circle (in) |
|
1/2 |
3.50 |
0.38 |
1.38 |
4 |
0.62 |
2.38 |
|
1 |
4.25 |
0.44 |
2.00 |
4 |
0.62 |
3.12 |
|
2 |
6.00 |
0.50 |
3.62 |
4 |
0.75 |
4.75 |
|
3 |
7.50 |
0.56 |
5.00 |
4 |
0.75 |
6.00 |
|
4 |
9.00 |
0.62 |
6.19 |
8 |
0.75 |
7.50 |
|
6 |
11.00 |
0.69 |
8.50 |
8 |
0.88 |
9.50 |
|
8 |
13.50 |
0.81 |
10.62 |
8 |
0.88 |
11.75 |
|
10 |
16.00 |
0.88 |
12.75 |
12 |
1.00 |
14.25 |
|
12 |
19.00 |
0.94 |
15.00 |
12 |
1.00 |
17.00 |
For Class 300:
|
NPS (in) |
OD (in) |
Thickness Min. (in) |
RF Dia. (in) |
Bolt Holes (No.) |
Bolt Hole Dia. (in) |
Bolt Circle (in) |
|
1/2 |
3.75 |
0.50 |
1.38 |
4 |
0.62 |
2.62 |
|
1 |
4.88 |
0.56 |
2.00 |
4 |
0.75 |
3.50 |
|
2 |
6.50 |
0.69 |
3.62 |
8 |
0.75 |
5.00 |
|
3 |
8.25 |
0.81 |
5.00 |
8 |
0.88 |
6.62 |
|
4 |
10.00 |
0.88 |
6.19 |
8 |
0.88 |
7.88 |
|
6 |
12.50 |
1.06 |
8.50 |
12 |
0.88 |
10.62 |
|
8 |
15.00 |
1.25 |
10.62 |
12 |
1.00 |
13.00 |
|
10 |
17.50 |
1.38 |
12.75 |
16 |
1.12 |
15.25 |
|
12 |
20.50 |
1.50 |
15.00 |
16 |
1.25 |
17.75 |
Dimensions are standard; actual weights vary slightly with Incoloy 800HT density. Custom machining available for specific tolerances.
Flange Dimensions, Types and Standards
Governing Standards & Sizes
Material Standard: Flanges are typically manufactured to ASTM B564 / ASME SB564.
Dimension & Pressure Class: Controlled by standards such as ANSI/ASME B16.5 (up to 24"), B16.47 Series A & B (larger diameters), and European standards (DIN, EN 1092).
Available Sizes: Commonly supplied from 1/2" NB (15 NB) up to 48" NB (1200 NB) or larger.
Common Flange Types
Manufacturers supply Incoloy 800HT in all standard configurations:
Weld Neck (WN)
Slip-On (SO)
Blind (BL)
Socket Weld (SW)
Lap Joint (LJ)
Ring Type Joint (RTJ)
Threaded (THD)
Pressure-Temperature Ratings
The maximum allowable working pressure depends on the flange class and operating temperature. The table below provides sample data for ASME B16.5 Class 150 and 300 flanges.
|
Temperature (°F) |
Max. Pressure - Class 150 (psi) |
Max. Pressure - Class 300 (psi) |
|
-20 to 100 |
275 |
720 |
|
400 |
195 |
515 |
|
700 |
110 |
430 |
|
1000 |
20 |
350 |
Incoloy 800HT Flange Applications
Petrochemical Processing: Ethylene furnace cracking tubes, pigtails, convection sections, and reformer assemblies.
Power Generation: Steam superheater tubes, heat exchangers, and high-temperature piping systems.
Industrial Furnaces: Radiant tubes, muffles, retorts, and other high-temperature furnace components.
Nuclear Power: Components for High-Temperature Gas-Cooled Reactors (HTGRs).
Trust our factory's Incoloy 800HT flanges for proven performance. With advanced forging and testing, we guarantee compliance and superior service life. Contact us to discuss your project needs.
