Amardeep Steel is a trusted supplier and exporter of Incoloy 800HT Flanges. The high temperature and pressure service variants of the Incoloy 800 series series, these flanges are designed to deliver creep resistance and structural stability above 1100 degree F, in applications where such properties are essential. The 800HT grade is the most stress rupture resistant of the conventional 800 and 800H grades with a controlled Al+Ti content of 0.85 to 1.20%, and a minimum anneal at 2100 degrees F. Incoloy 800HT Pipes and Tubes,Incoloy Plates and Sheets, andIncoloy Products are available in a variety of specifications to meet the needs of the petrochemical, power generation and heat-treatment industries worldwide.
Table of Contents
- Incoloy 800HT Flanges Specifications
- What Sets Incoloy 800HT Apart from 800 and 800H
- Types of Incoloy 800HT Flanges
- Chemical Composition of Incoloy 800HT
- Mechanical Properties of Incoloy 800HT Flanges
- Incoloy 800HT in High-Temperature and Creep-Critical Service
- Applications of Incoloy 800HT Flanges
- Incoloy 800HT Equivalent Grades and Trade Names
- Dimensions of Incoloy 800 / 800H / 800HT Flanges
- Testings for Incoloy 800HT Flanges
- Frequently Asked Questions
Need Incoloy 800HT Flanges?
Amardeep Steel supplies ASTM B564 / ASME SB564 Incoloy 800HT Flanges (UNS N08811) with full EN 10204 3.1 mill test certificates, available in all types, sizes, and pressure classes, ready for petrochemical, power generation, and heat-treatment applications.
Incoloy 800HT Flanges Specifications
| Field | Value |
|---|---|
| Grade | Incoloy Alloy 800 / 800H / 800HT / UNS N08800 / N08810 / N08811 |
| Standard | ASTM B564, ASME SB564 |
| Dimensions | ANSI / ASME B16.5, B16.47 Series A & B, B.16.48, BS4504, BS10, DIN, EN-1092, MSS SP44 |
| Size | 1/2" - 48" (15NB - 1200NB) |
| Class / Pressure Rating | ASME Class 150, 300, 600, 900, 1500 and 2500; DIN/EN PN6 to PN64 Dimensional Standards: ASME B16.5, ASME B16.47 Series A & B, ASME B16.36, ASME B16.48, EN 1092-1, DIN, BS 10, BS 4504 and JIS Documentation: EN 10204 3.1 MTC, PMI report, heat number traceability, dimensional inspection report and third-party inspection on request. |
| Form | Slip on Flanges (SORF), Threaded Flanges, Weld neck Flanges (WNRF), Blind Flanges, Socket weld Flanges, Lap Joint Flanges, Ring Type Joint Flanges, Spectacle Blind Flanges, Spacer Ring Flanges, Long weld Neck Flanges, Nipo Flange, Nipolet Flanges, Plate Flanges, Flat Flange, Orifice Flanges, Forged Flanges |
| Flange Face Type | Flat Face (FF), Raised Face (RF), Ring Type Joint(RTJ) |
What Sets Incoloy 800HT Apart from 800 and 800H
| Property | Incoloy 800 (N08800) | Incoloy 800H (N08810) | Incoloy 800HT (N08811) |
|---|---|---|---|
| Carbon % | Max 0.10 | 0.05 to 0.10 | 0.06 to 0.10 |
| Al + Ti % | 0.30 to 1.20 | 0.30 to 1.20 | 0.85 to 1.20 (restricted) |
| Min Anneal Temp | Standard | High Temp | 2100 degrees F (1149 degrees C) |
| Grain Size (ASTM) | Not controlled | Coarser than 5 | Coarser than 5 |
| Max Service Temp | Up to 1100 degrees F | Up to 1500 degrees F | Up to 1800 degrees F |
| Creep / Rupture Strength | Standard | Improved | Optimum |
| Primary Use | General corrosion service | High-temp pressure service | Extended creep-critical service |
| Werkstoff No. | 1.4876 | 1.4876H / 1.4958 | 1.4876HT / 1.4959 |
Selection Guide: Choose Incoloy 800HT flanges when the service temperature remains above 1100 degrees F for long periods and creep rupture strength is a design requirement. Choose 800H for high-temperature pressure service where restricted Al+Ti is not specified. Choose 800 for general corrosion and oxidation service below creep-critical temperature ranges.
Chemical Composition of Incoloy 800HT
| Element | Min % | Max % |
|---|---|---|
| Nickel (Ni) | 30.0 | 35.0 |
| Chromium (Cr) | 19.0 | 23.0 |
| Iron (Fe) | Remainder | Remainder |
| Carbon (C) | 0.06 | 0.10 |
| Aluminum (Al) | 0.15 | 0.60 |
| Titanium (Ti) | 0.15 | 0.60 |
| Al + Ti (combined) | 0.85 | 1.20 |
| Manganese (Mn) | 0 | 1.50 |
| Silicon (Si) | 0 | 1.00 |
| Sulfur (S) | 0 | 0.015 |
| Copper (Cu) | 0 | 0.75 |
Mechanical Properties of Incoloy 800HT Flanges
| Property | Value |
|---|---|
| Tensile Strength (min) | 75 ksi (520 MPa) |
| Yield Strength 0.2% Offset (min) | 30 ksi (205 MPa) |
| Elongation (min) | 30% |
| Hardness (Brinell) | Max 192 HBW |
| Density | 0.287 lb/in3 (7.94 g/cm3) |
| Melting Range | 2475 to 2525 degrees F (1357 to 1385 degrees C) |
| Modulus of Elasticity (RT) | 28.0 x 10^6 psi (193 GPa) |
| Poisson's Ratio | 0.34 |
| Specific Heat (RT) | 0.11 BTU/lb-degrees F (460 J/kg-degrees C) |
| Thermal Conductivity (70 degrees F) | 6.7 BTU/h-ft-degrees F (11.6 W/m-degrees C) |
| Coefficient of Thermal Expansion (70-212 degrees F) | 7.9 x 10^-6 in/in/degrees F (14.2 mm/m/degrees C) |
Incoloy 800HT in High-Temperature and Creep-Critical Service
Incoloy 800HT flanges are the standard selection when design engineers must satisfy ASME Section I, Section III, or Section VIII creep-allowable stress requirements above 1100 degrees F. The alloy does not embrittle even after prolonged service in the 1200 to 1600 degrees F range, a temperature band where most austenitic stainless steels are prone to sigma-phase formation and brittle fracture.
Key High-Temperature Performance Attributes
| Attribute | Performance Detail |
|---|---|
| Creep Resistance | Superior to both 800 and 800H due to restricted Al+Ti and mandatory coarse grain anneal |
| Stress Rupture Strength | Optimized for continuous service up to 1800 degrees F (982 degrees C) |
| Oxidation Resistance | Excellent in air and steam environments up to 1800 degrees F |
| Carburization Resistance | High; suitable for ethylene pyrolysis and hydrocarbon cracking atmospheres |
| Nitriding Resistance | Effective protection in ammonia-bearing furnace environments |
| Sigma Phase Embrittlement | Not susceptible even after long-term service at 1200 to 1600 degrees F |
| Thermal Cycling Stability | Microstructurally stable through repeated thermal cycles |
| Sensitization Range Behavior | Higher carbon and Ti/Al stabilizers reduce intergranular attack risk vs plain 800 |
Incoloy 800HT Equivalent Grades and Trade Names
| Standard | Designation |
|---|---|
| UNS | N08811 |
| Werkstoff Number | 1.4876HT / 1.4959 |
| ASTM / ASME | ASTM B564 / ASME SB564 (Flanges) |
| EN | EN 10204-3.1 |
| JIS | NCF 800HT |
| Trade Name (Special Metals) | INCOLOY alloy 800HT |
| Common Alternate Names | Alloy 800HT, UNS N08811 Flanges, Ferrochronin 800HT, Nicrofer 3220HT |
Types of Incoloy 800HT Flanges
Alloy 800 Blind Flanges
.webp)
Alloy 800 BLRF Flanges (Blind Raised Face Flanges)
Alloy 800 Flat Flanges
Alloy 800 Lap-joint Flanges
Alloy 800 Nipolet Flanges
Alloy 800 Reducing Flanges
Alloy 800 SORF Flanges
Alloy 800 Spacer Ring Flanges
Alloy 800 Spectacle Flanges
.webp)
Alloy 800 SWRF Flanges (Socket Weld Raised Face Flanges)
Alloy 800 Weldo Flanges
Alloy 800 WNRF Flanges
Applications of Incoloy 800HT Flanges
- Chemical tanks
- Pulp & Paper Industries
- Petrochemical Industries
- Power Generation Industries
- Oil & Gas Industries
- Desalination
- Architecture and Construction
- Food Processing Equipment
- Biofuels plant
- Cargo tanks for ships and trucks
- Chemical Industries Pumps, fans, centrifuges, sulphur melting coils,
- Digester in sulphate and sulfite plants, blow tanks, blow lines
Dimensions of Incoloy 800 / 800H / 800HT Flanges
| Size in Inch | Size in mm | Outer Diameter A | Flange Thickness B | Hub OD C | Weld Neck OD D | Welding Neck Length E | Bore F | RF Diameter G | RF Height H | PCD I | Weld Face J |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 15 | 90 | 9.6 | 30 | 21.3 | 46 | Refer Note | 34.9 | 2 | 60.3 | 1.6 |
| 3/4 | 20 | 100 | 11.2 | 38 | 26.7 | 51 | 42.9 | 2 | 69.9 | 1.6 | |
| 1 | 25 | 110 | 12.7 | 49 | 33.4 | 54 | 50.8 | 2 | 79.4 | 1.6 | |
| 1 1/4 | 32 | 115 | 14.3 | 59 | 42.2 | 56 | 63.5 | 2 | 88.9 | 1.6 | |
| 1 1/2 | 40 | 125 | 15.9 | 65 | 48.3 | 60 | 73 | 2 | 98.4 | 1.6 | |
| 2 | 50 | 150 | 17.5 | 78 | 60.3 | 62 | 92.1 | 2 | 120.7 | 1.6 | |
| 2 1/2 | 65 | 180 | 20.7 | 90 | 73 | 68 | 104.8 | 2 | 139.7 | 1.6 | |
| 3 | 80 | 190 | 22.3 | 108 | 88.9 | 68 | 127 | 2 | 152.4 | 1.6 | |
| 3 1/2 | 90 | 215 | 22.3 | 122 | 101.6 | 70 | 139.7 | 2 | 177.8 | 1.6 | |
| 4 | 100 | 230 | 22.3 | 135 | 114.3 | 75 | 157.2 | 2 | 190.5 | 1.6 | |
| 5 | 125 | 255 | 22.3 | 164 | 141.3 | 87 | 185.7 | 2 | 215.9 | 1.6 | |
| 6 | 150 | 280 | 23.9 | 192 | 168.3 | 87 | 215.9 | 2 | 241.3 | 1.6 | |
| 8 | 200 | 345 | 27 | 246 | 219.1 | 100 | 269.9 | 2 | 298.5 | 1.6 | |
| 10 | 250 | 405 | 28.6 | 305 | 273 | 100 | 323.8 | 2 | 362 | 1.6 | |
| 12 | 300 | 485 | 30.2 | 365 | 323.8 | 113 | 381 | 2 | 431.8 | 1.6 | |
| 14 | 350 | 535 | 33.4 | 400 | 355.6 | 125 | 412.8 | 2 | 476.3 | 1.6 | |
| 16 | 400 | 595 | 35 | 457 | 406.4 | 125 | 469.9 | 2 | 539.8 | 1.6 | |
| 18 | 450 | 635 | 38.1 | 505 | 457.2 | 138 | 533.4 | 2 | 577.9 | 1.6 | |
| 20 | 500 | 700 | 41.3 | 559 | 508 | 143 | 584.2 | 2 | 635 | 1.6 | |
| 24 | 600 | 815 | 46.1 | 663 | 610 | 151 | 692.2 | 2 | 749.3 | 1.6 |
Testings (Destructive, Non Destructive) for Incoloy 800HT Flanges
- Positive Material Identification - PMI Testing
- Chemical Analysis - Spectro Analysis
- Mechanical Testing Such as Tensile, Elongation, Reduction of Area
- Micro Test
- Macro Test
- Hardness Test
- Pitting Resistance Test
- Intergranular Corrosion (IGC) Test
- Flaring Test
- Flattening Test
- Hydrostatic Test
- Hydrogen-Induced Cracking (HIC) Test, NACE TM0284
- Sulfide Stress Corrosion Cracking (SSC), NACE TM 0177
- Radiography Test
- Dye Penetrant Test (DP Test)
- Ultra Sonic Test (UT)
- Eddy Current Testing
- Impact Test
- Bend Test
Frequently Asked Questions
What is the difference between Incoloy 800H and 800HT flanges?
800HT has a restricted Al+Ti of 0.85 to 1.20% and requires a 2100 degrees F minimum anneal, giving optimum creep rupture strength above 1100 degrees F. 800H has a wider Al+Ti range of 0.30 to 1.20%.
What standard governs Incoloy 800HT flanges?
Incoloy 800HT flanges are manufactured to ASTM B564 / ASME SB564, UNS N08811. Dimensional standards include ASME B16.5, B16.47, BS 4504, DIN, and JIS depending on the specified flange type.
Up to what temperature can Incoloy 800HT flanges be used?
Incoloy 800HT flanges are rated for sustained service up to approximately 1800 degrees F (982 degrees C) and do not embrittle during prolonged use in the 1200 to 1600 degrees F range where stainless steels may fail.
Is Incoloy 800HT the same as Inconel 800HT?
No. Incoloy and Inconel are distinct alloy families. Incoloy 800HT (N08811) is a nickel-iron-chromium alloy. Inconel alloys such as 600 or 625 have a nickel-chromium base. The term Inconel 800HT is commercially incorrect.
What flange face types are available in Incoloy 800HT?
Available face types include Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), Lap-Joint Face (LJF), Male-Female (MF), and Tongue and Groove (T+G) to match application and pressure class requirements.
What pressure classes are available for Incoloy 800HT flanges?
Incoloy 800HT flanges are available in ASME pressure classes 150#, 300#, 600#, 900#, 1500#, and 2500#, as well as DIN pressure ratings PN6 through PN64, per ANSI B16.5 and B16.47.
Get a Quote for Incoloy 800HT Flanges
Amardeep Steel supplies ASTM B564 Incoloy 800HT Flanges (UNS N08811) in all standard types, sizes, and pressure classes with full material traceability and EN 10204 3.1 test certificates. Contact our technical sales team for pricing, lead times, and custom specifications.
