Inconel 825 Pipes and Tubes
Inconel 825 pipes and tubes are manufactured with Incoloy 825 (UNS N08825) which is a part of austenitic grade with the content like iron, chromium, and nickel and minor addition of molybdenum, titanium, and copper. Inconel 825 pipe and tubes are developed to provide up to the mark resistance to various corrosive media even in oxidizing and reducing environments.
Inconel 825 pipe and tubes with their nickel content are resistant to chloride stress corrosion cracking. The amalgamation of molybdenum and copper gives improved corrosion resistance in reducing environments as compared to its standard grade.
Specifications
Inconel 825 Seamless Pipe : ASTM/ASME B 423 / SB 423
Inconel 825 Seamless tube : ASTM/ASME B 423 / SB 423
Inconel 825 ERW Pipe : ASTM/ASME B 705/ SB 705
Inconel 825 ERW Tube : ASTM/ASME B 704/ SB 704
Chemical Properties
| GRADE | Cr | Cu | Mo | Co | Al | Ti | C | Fe | Mn | Si | P | S | Ni | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| INCONEL 825 | MIN % | 19.5 | 1.5 | 2.5 | – | – | 0.6 | – | 22 | – | – | – | – | 38 |
| MAX % | 23.5 | 3 | 3.5 | 1 | 0.2 | 1.2 | 0.05 | – | 1 | 0.5 | 0.015 | 0.03 | 46 |
Production Process
Inconel 825 or UNS N08825 are manufactured such as ERW ( Electric Resistance Welded), Seamless and EFW ( Electric Fusion Welding) Pipes and Tubes with different forms such as round, square, rectangle, etc. with particular ends like the plain end, bevel end, and threaded end with normal thickness of different schedule which range from SCH 5 to SCH XXS..
Specifications
| GRADE | UNS | DIN | AFNOR |
|---|---|---|---|
| INCONEL 825 | NO8825 | 2.4858 | NC 21 FeDU |
The process through which Inconel 825 pipes and tubes can be manufactured with various processes like cold pilgering process, extrusion process, tube mill process, and piercing process which need to be followed by heat treatment and mechanical testing.
Fabrication and Heat Treatment
The hot working temperature range for Inconel 825 tube and pipes is 1600°F to 2150°F (870°C to 1180°C). For optimal corrosion resistance, last hot working should be done at temperatures between 1600°F and 1800°F (870°C and 980°C). Hot working should be followed by air cool or faster.
Inconel 825 products like pipes and tubes are heat treated during the manufacturing process to form the optimal combination of stabilization, corrosion resistance, mechanical properties, and formability. To maintain these properties during fabrication, annealing should be done in between 1700°F to 1800°F (930°C to 980°C) and rapid air cooling or water quenching is necessary after the process.
Properties
The machining of Inconel 825 is moderately simple. All the regular techniques can be promptly used. Inconel 825 tubes and pipes have ideal machining attributes in tempered condition. The grade Inconel 825 comes with lesser operating hardness due to its copper content material. It can therefore be applied at cryogenic temperatures to extreme temperatures without a lack of mechanical properties.
Mechanical Properties
| Grade | Tensile Strength (MPa) | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min |
|---|---|---|---|
| 825 | 550 MPa | 220 MPa | 30 |
Inconel Alloy 825 is easily weldable by regular processes such as [GMAW (MIG), GTAW (TIG), SMAW (manual), SAW] while welding the joint must be clean to eliminate contamination of the weld pool.
Physical Properties
| Grade | Density (g/cm3) | Elastic Modulus (GPa) | Mean Co-eff of Thermal Expansion (μm/m/°C) | Thermal Conductivity (W/m.K) | Specific Heat (J/Kg.K) | Electrical Resistivity (μΩ.m) | ||
|---|---|---|---|---|---|---|---|---|
| Inconel 825 | 27-204°C | 0-315°C | at 93°C | at 204°C | 0-100°C | |||
| 7.82 | 190 | 14.9 | 14.2 | 12.3 | 14.1 | 440 | 1.13 | |
Application
Inconel 825 pipe and tubes are popularly used in ammonium chloride & phosphoric acid solution. Extreme heat exchangers with working conditions for refrigerant purpose alloy 825 is the best option. Inconel 825 tube suited pipelines of marine applications & offshore equipment are of material Incoloy 825.
- Condensers in heat exchangers
- Oil and gas well equipment on the seashore
- Hydraulic systems
- Chemical injection lines
- Chemical process equipment and vessels
- Downhole control lines
- Control and instrumentation
- Acid Production
- Nuclear fuel processing.
NOTE: Inconel 825 Pipes and Tubes is a registered trademark of Special Metals Corporation.
