Inconel 690 Flanges
Inconel 690 Flanges ( UNS N06690 ) Manufacturer & Supplier
Inconel 690 Flanges, designated as UNS N06690, are high-chromium nickel alloy flanges designed for outstanding corrosion resistance and exceptional performance at elevated temperatures. With a chromium content of approximately 30%, this alloy offers superior resistance to hot corrosive environments, especially those containing sulfur, chlorine, and oxidizing chemicals.
Inconel 690 Flanges are widely preferred in nuclear power plants, steam generators, chemical processing units, heat-treating equipment, and furnace components due to their robust metallurgical stability and long-term service reliability. Their resistance to stress-corrosion cracking and excellent mechanical strength make them highly suitable for demanding industrial applications.
Key Features
Excellent corrosion resistance in oxidizing and reducing environments
High chromium content ensures superior resistance to hot, acidic, and chloride-containing media
Exceptional performance in high-temperature environments up to 1200°C
Outstanding stress-corrosion cracking and pitting resistance
High mechanical strength and thermal stability
Excellent oxidation and carburization resistance
Reliable in steam, wastewater, and nuclear reactor systems
Good weldability and fabricability
Specifications
| Specification | Details |
|---|---|
| Standard | ASTM B564, ASME SB564 |
| Material | Inconel 690 / Alloy 690 |
| UNS Number | N06690 |
| Werkstoff Nr. | 2.4642 |
| Flange Types | WN, SO, BL, SW, Threaded, LJ, RTJ, Orifice, Long Weld Neck |
| Size Range | ½” to 48” |
| Pressure Rating | Class 150 to 2500 / PN6–PN400 |
| Manufacturing | Forged, Heat Treated, Machined |
| Face Type | RF, RTJ, FF |
| Standards | ANSI, ASME, DIN, EN, JIS, BS |
Equivalent Grades
| Standard | Grade |
|---|---|
| UNS | N06690 |
| Werkstoff | 2.4642 |
| Trade Name | Inconel 690, Alloy 690 |
Available Sizes
Flange Size: ½” to 48”
Standards: ASME B16.5, B16.47, B16.48
Custom Sizes: Available upon request
Chemical Composition
| Element | Percentage (%) |
|---|---|
| Nickel (Ni) | ≥ 58.0 |
| Chromium (Cr) | 27.0 – 31.0 |
| Iron (Fe) | 7.0 – 11.0 |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 0.5 |
| Carbon (C) | ≤ 0.05 |
| Titanium (Ti) | ≤ 0.5 |
| Aluminum (Al) | ≤ 0.5 |
| Sulfur (S) | ≤ 0.015 |
Mechanical Properties
| Property | Value |
|---|---|
| Density | 8.19 g/cm³ |
| Tensile Strength | 415 MPa min |
| Yield Strength | 205 MPa min |
| Elongation | 30% min |
| Hardness | 85–95 HRB |
Physical Properties
| Property | Value |
|---|---|
| Melting Point | 1343–1377°C |
| Thermal Conductivity | 14 W/m·K |
| Electrical Resistivity | 1.15 µΩ·m |
| Specific Heat | 0.42 kJ/kg·K |
| Modulus of Elasticity | 207 GPa |
Types of Inconel 690 (UNS N06690) Flanges
Weld Neck Flanges
Slip-On Flanges
Blind Flanges
Socket Weld Flanges
Threaded Flanges
Lap Joint Flanges
Ring Type Joint (RTJ) Flanges
Orifice Flanges
Reducing Flanges
Long Weld Neck Flanges
Corrosion Resistance
Inconel 690 (UNS N06690) offers outstanding corrosion resistance in:
Hot acidic and alkaline environments
Steam and boiling aqueous solutions
Oxidizing chemicals (nitric acid, perchlorates)
Chloride-containing environments
Sulfur-bearing atmospheres
High-temperature gaseous corrosion
Stress-corrosion cracking conditions
Its exceptionally high chromium content provides superior protection in aqueous and high-temperature oxidizing environments.
Heat Resistance
Withstands temperatures up to 1200°C
Excellent oxidation resistance in air and combustion gases
Highly stable under thermal cycling
Suitable for furnace hardware, burners, petrochemical heaters, steam generators
Heat Treatment
Typically supplied in the annealed condition
Annealing temperature: 1850–2050°F (1010–1120°C) followed by rapid cooling
Heat treatment maximizes ductility, mechanical stability, and corrosion resistance
Welding
Inconel 690 (UNS N06690) exhibits excellent weldability using:
GTAW (TIG)
GMAW (MIG)
SMAW
FCAW
Filler Metals:
Inconel Filler 52, 52M, 82
No preheat required; however, controlled heat input is recommended.
Fabrication
Good hot and cold workability
Hot working temperature: 1700–2200°F (925–1200°C)
Can be formed, forged, and machined easily
Carbide tooling recommended for machining
Demonstrates good formability and forgeability
Applications
Nuclear steam generator tubes and components
Chemical processing equipment
Heat-treating furnaces
Petrochemical heaters and reformer tubes
Industrial boilers and steam generators
Thermal oxidizers
Burner and flare components
Power generation systems
Wastewater treatment plants