China Manufacturer of API 6ACRA STUD Bolt and Nut ASTM B637 UNS N07718 Inconel 718
N07718, Alloy 718, often referred to as Inconel 718, is a high-strength, corrosion-resistant nickel chromium alloy supplied in the hot worked, solution annealed and age hardened condition.
N07718 stud bolts are manufactured from Inconel 718, a precipitation-hardened nickel-based alloy. The unique composition of this alloy includes:
- Nickel (50-55%): Provides outstanding corrosion resistance.
- Chromium (17-21%): Enhances oxidation resistance.
- Molybdenum & Niobium: Improve strength and stability under stress.
- Iron, Titanium, and Aluminum: Further strengthen the alloy’s properties.
These bolts are renowned for their high tensile and yield strength, even in extreme temperatures ranging from cryogenic levels up to 700°C (1290°F).
N07718 bolt Chemical composition:
| Alloy | % | Ni | Cr | Fe | Mo | Nb | Co | C | Mn | Si | S | Cu | Al | Ti |
| inconel 718 | Min. | 50 | 17 | balance | 2.8 | 4.75 | 0.2 | 0.7 | ||||||
| Max. | 55 | 21 | 3.3 | 5.5 | 1 | 0.08 | 0.35 | 0.35 | 0.01 | 0.3 | 0.8 | 1.15 |
N07718 Stud bolt mechanical properties
in the room temperature:
| Alloy | Tensile strength Rm N/mm² | Yield strength R P0. 2N/mm² | Elongation A 5 % | Brinell hardness HB |
| Solution treatment | 965 | 550 | 30 | ≤363 |
Standards and Specifications
N07718 stud bolts are manufactured to meet industry standards, including:
- ASTM B637: Covers age-hardened Inconel 718 fasteners.
- ASME and API Standards: API 6ACRA
Inconel 718/N07718 Stud bolt Heat treatment
Two heat treatments are generally utilized for INCONEL alloy 718: •Solution anneal at 1700-1850°F followed by rapid cooling, usually in water, plus precipitation hardening at 1325°F for 8 hours, furnace cool to 1150°F, hold at 1150°F for a total aging time of 18 hours, followed by air cooling.
Inconel 718/N07718 Stud bolt character
- Good strength/ductility properties from sub-zero temperatures to over 750°C
- Acceptable corrosion resistance and fatigue resistance in a wide variety of corrosive chemicals such as seawater and industrial acids
- Non-magnetic and spark resistant
- Excellent resistance to stress corrosion cracking, chloride stress corrosion & sulphide stress cracking
- High fatigue strength in seawater
Inconel 718/N07718 Stud bolt Applications:
- Oil & Gas industry wellhead components, gate valves, choke stems, fasteners, packers, clamps, tubing hangers, downhole equipment
- Power generation applications such as fasteners, turbines
- Aerospace components
- Nuclear power plant containment vessels, valves
- Engineering applications between 750°C and cryogenic temperatures
Benefits of N07718 Stud Bolts
- Long-lasting performance in aggressive environments.
- Resistant to fatigue and creep deformation.
- Complies with stringent industry standards (e.g., ASTM B637).