Inconel 718 Round Bar & Pipe Supplier in India — N07718

Inconel 718's exceptional strength comes from precipitation hardening through gamma double-prime (γ") Ni3Nb precipitates that form during aging heat treatment. The alloy contains approximately 5% niobium which combines with nickel to form these coherent precipitates within the FCC matrix. The standard heat treatment involves solution treating at 980°C followed by two-step aging at 720°C (8 hours) and 620°C (8 hours). This produces yield strengths of 1035-1240 MPa — roughly 3x stronger than solution-annealed Inconel 625. The γ" precipitates are sluggish to form, giving 718 excellent weldability compared to other precipitation-hardened superalloys.

Inconel 718 and 625 differ fundamentally in their strengthening mechanism and application range. Inconel 718 is precipitation-hardened (age-hardenable) achieving yield strength of 1035+ MPa, while 625 is solid-solution strengthened with yield strength of only 415 MPa. However, 625 has superior corrosion resistance due to higher Mo content (9% vs 3%) and can operate at higher temperatures for corrosion service. Inconel 718 is limited to approximately 700°C for structural applications because γ" precipitates become unstable above this temperature. Choose 718 when high strength is primary (aerospace fasteners, turbine discs), and 625 when corrosion resistance is primary (marine, chemical processing).

Inconel 718 is considered one of the more machinable nickel superalloys, though still challenging compared to steel. In the solution-annealed condition (before aging), it machines reasonably well using carbide tooling with low cutting speeds (15-25 m/min), high feed rates, and generous coolant flow. After age hardening, machinability decreases significantly due to the high hardness (36-44 HRC). Best practices include: rigid machine setup to minimize vibration, sharp positive-rake carbide or ceramic inserts, constant engagement to avoid work hardening, and high-pressure coolant delivery. Most aerospace components are rough-machined in the annealed condition and finish-machined after aging.

Creative Metal Industries supplies Inconel 718 with full aerospace traceability per AMS 5662 (bar, solution treated), AMS 5663 (bar, solution treated and aged), AMS 5664 (bar, high strength), and AMS 5589/5590 (sheet/plate). All material is supplied with DFARS compliance documentation, full chemical and mechanical test certificates per ASTM B637, and heat-lot traceability. We source from aerospace-approved mills including Special Metals, Carpenter Technology, ATI, and VDM Metals. Dual certification (ASTM + AMS) is standard. Contact us for specific OEM-approved material requirements.

Inconel 718 is one of the most expensive commercial nickel superalloys, with pricing in India typically ranging from Rs 3,000 to Rs 8,000 per kg depending on product form, size, condition, and quantity. Round bars in standard sizes (25-100mm) are at the lower end, while precision-ground bars, small diameters, and aerospace-certified material command premium pricing. The high cost reflects the expensive raw materials (nickel, niobium, molybdenum), complex vacuum melting (VIM+VAR) required for aerospace grades, and extensive testing. Contact Creative Metal Industries at +91 99982 80619 for competitive pricing from our ready stock inventory.

Yes, Inconel 718 exhibits excellent mechanical properties at cryogenic temperatures down to -253°C (liquid hydrogen temperature). Unlike many materials that become brittle at low temperatures, Inconel 718 actually shows increased strength with good ductility and toughness at cryogenic conditions. This makes it ideal for liquid oxygen and liquid hydrogen turbopump components in rocket engines, cryogenic valves, LNG plant equipment, and superconducting magnet structures. The combination of high strength at both elevated (up to 700°C) and cryogenic temperatures makes Inconel 718 uniquely versatile among engineering alloys.