Alloy 625 Seamless Pipes Nickel Alloy Pipe UNS N06625
Alloy 625, also known as Inconel 625, is a nickel-chromium-molybdenum alloy known for its high strength, excellent fabricability, and outstanding corrosion resistance. This superalloy is widely used in various challenging environments due to its versatility and performance.
Chemical Composition:
- Nickel (Ni): 58.0 min
- Chromium (Cr): 20.0 - 23.0
- Molybdenum (Mo): 8.0 - 10.0
- Niobium (Nb) + Tantalum (Ta): 3.15 - 4.15
- Iron (Fe): 5.0 max
- Cobalt (Co): 1.0 max
- Manganese (Mn): 0.50 max
- Silicon (Si): 0.50 max
- Aluminum (Al): 0.40 max
- Titanium (Ti): 0.40 max
- Carbon (C): 0.10 max
- Phosphorus (P): 0.015 max
- Sulfur (S): 0.015 max
Key Properties:
- High Strength: Alloy 625 maintains high strength and toughness at temperatures ranging from cryogenic up to 982°C (1800°F).
- Corrosion Resistance: Exceptional resistance to pitting, crevice corrosion, and intergranular attack. It also offers excellent resistance to chloride-ion stress-corrosion cracking.
- Oxidation Resistance: Superior oxidation resistance at temperatures up to 1093°C (2000°F).
- Fabricability: Easily fabricated by conventional techniques, including welding and forming.
Applications:
- Aerospace: Turbine engines, exhaust systems, and rocket components due to its high-temperature strength and oxidation resistance.
- Marine: Marine environments and offshore oil and gas industries for its outstanding resistance to seawater corrosion.
- Chemical Processing: Equipment and piping in chemical processing plants due to its resistance to a wide range of corrosive environments.
- Power Generation: Heat exchangers, reactor cores, and steam generator tubing in nuclear power plants.
Specifications and Standards:
Alloy 625 seamless pipes are typically produced according to various international standards, including:
- ASTM B444 / ASME SB444
- ASTM B705 / ASME SB705
- API 5LC
Mechanical Properties:
- Tensile Strength: 120 ksi (827 MPa) min
- Yield Strength (0.2% offset): 60 ksi (414 MPa) min
- Elongation: 30% min
- Hardness: Typically in the range of 200 - 250 HB
Manufacturing Process:
Seamless pipes are produced by extrusion or rotary piercing followed by drawing or rolling to achieve the final dimensions and properties. This process ensures a pipe without any weld seams, offering superior strength and corrosion resistance.
Dimensional Range:
- Outer Diameter (OD): Typically ranges from 0.5 inches to 24 inches.
- Wall Thickness: Available in schedules ranging from SCH 5S to SCH XXS, depending on the application requirements.
Surface Finish:
- Pipes can be supplied with various surface finishes, including pickled, polished, or with a specific roughness as required by the application.
| Grade | UNS | Density | Tensile Strength (MPa min) | Yield Strength (MPa min) | Reduction of Area min (%) | Elongation min (%) | Hardness (HRC) |
| INCONEL 625 | N06625 | 8.44 | 827MPa | 414MPa min | / | 30% min | HRC 35 max |
The following table lists only some of the grades:
| Grade | UNS | DIN |
| Monel 400 | N04400 | W.Nr. 2.4360 |
| Monel K-500 | N05500 | W.Nr. 2.4375 |
| Inconel 625 | N06625 | W.Nr. 2.4856 |
| Inconel 718 | N07718 | W.Nr. 2.4668 |
| Inconel X-750 | N07750 | W. Nr. 2.4669 |
| Inconel 600 | N06600 | W.Nr. 2.4816 |
| Inconel 601 | N06601 | W.Nr. 2.4851 |
| Incoloy 825 | N08825 | W.Nr. 2.4858 |
| Incoloy A-286 | S66286 | W.Nr.1.4980 |
| Hastelloy C-276 | N10276 | W.Nr.2.4819 |
| Hastelloy C-22 | N06022 | W.Nr.2.4602 |
| Hastelloy C-4 | N06455 | W.Nr.2.4610 |
| Hastelloy B-3 | N10675 | W.Nr.2.4600 |
| Hastelloy X | N06002 | W.Nr.2.4665 |
| Hastelloy B-2 | N10665 | W.Nr.2.4617 |
