Inconel 718 alloy tubing is based on a nickel matrix with a precise ratio of chromium, niobium, molybdenum, and other elements, maintains long-term stability in high-temperature, high-pressure, and corrosive environments, making it the preferred solution for piping systems under extreme conditions. HT PIPE is a inconel 718 seamless tube supplier with 15+ export experience. Contact us for more information and quotes for free!
alloy 718 material Chemical Composition
Nickel (Ni) 50%-55% serves as the base metal, ensuring toughness and high-temperature stability. Chromium (Cr) 17%-21% enhances oxidation resistance and corrosion resistance. Niobium (Nb) 4.75%-5.50% and Molybdenum (Mo) 2.8%-3.3% form γ'' and γ' strengthening phases, significantly increasing strength.
Iron (Fe) is the balance, while Titanium (Ti) 0.65%-1.15% and Aluminum (Al) 0.2%-0.8% promote precipitation hardening, and the content of trace elements such as carbon (C), manganese (Mn), and silicon (Si) is controlled to optimize processing performance and microstructure stability.
inconel n07718 pipe Key Performance Advantages
Mechanical Properties: At room temperature, tensile strength ≥1300MPa, yield strength ≥1100MPa, and elongation remains at 20%-30%, strength remains virtually undiminished in high-temperature environments below 650℃, possessing excellent creep resistance, fatigue resistance, and fracture toughness, far exceeding ordinary stainless steel pipes.
Corrosion Resistance: Inconel 718 alloy tubing has strong resistance to oxidizing environments, reducing acids, chloride stress corrosion cracking, and pitting corrosion. It can operate stably in harsh media such as high-temperature steam, acidic gases, and hydrogen sulfide, making it suitable for corrosive conditions in marine and chemical industries.
Physical and Processing Properties: Density is approximately 8.2 g/cm³, melting point is 1300-1400℃, and it has a low coefficient of thermal expansion, resulting in excellent dimensional stability during thermal cycling. It can be formed through conventional processes such as welding, forging, and machining. Its welding performance is outstanding among nickel-based superalloys, and it is not susceptible to strain aging cracking.
astm b163 inconel 718 pipe Specifications and Product Forms
Applicable Standards: ASTM B163, ASME SB-163, SAE AMS 5589/5590, DIN 17751, ISO NiCr19Nb5Mo3, etc.
Similar Grades: UNS N07718 (USA), Werkstoff Nr. 2.4668 (Germany)
Product Forms: Seamless tubes, welded tubes (ERW/EFW), available in round, square, rectangular, and other cross-sections, end finishes include plain ends, beveled ends, and threaded ends.
Specification Range: Seamless tube outer diameter 1/4" NB-6" NB, welded tube outer diameter 1" NB-16" NB, wall thickness follows SCH20, SCH40, SCH80, XXS series, lengths available in single random lengths, double random lengths, and custom cut lengths.
alloy n07718 Manufacturing and Processing Highlights
alloy 2.4668 pipe Core Manufacturing Process
Ingots are prepared using Vacuum Induction Melting (VIM) + Electroslag Remelting (ESR) process to control impurity content and homogenize the composition. After forging and extrusion to form tube blanks, they are processed to the target size through cold drawing or hot rolling.
Subsequent solution treatment (approximately 980℃) and aging treatment (holding at 720℃ for 8 hours, furnace cooling to 620℃ and holding for another 8 hours, then air cooling) promote the precipitation of strengthening phases, improving product strength and hardness. Finally, ultrasonic and radiographic non-destructive testing is performed to ensure surface finish and internal quality meet standards.
inconel n07718 tubing Welding Process Control
Welding must follow the low heat input principle, controlling the current and increasing the welding speed. Interpass temperature must be strictly maintained below 150℃ to reduce the heat-affected zone and the precipitation of harmful phases.
ERNiFeCr-2 homologous welding wire is preferred, while ERNiCrMo-4 heterogeneous welding wire can be used in complex conditions to improve crack resistance, standard aging heat treatment must be performed after welding to dissolve harmful phases such as Laves phase and restore the mechanical properties and corrosion resistance of the weld.
