ASTM B670 Alloy 718 Plate | UNS N07718 | Inconel 718

Shaanxi Shangyou Stainless Steel Co., Ltd. supplies Nickel Alloy 718, also known as Inconel 718, identified as UNS N07718 and Werkstoff 2.4668, in plate, sheet, and strip form according to ASTM B670 / ASME SB-670 and aerospace standard AMS 5596.

Nickel Alloy 718 is a precipitation-hardenable nickel-chromium alloy containing significant amounts of iron, niobium, and molybdenum, along with aluminum and titanium. The alloy is designed for high-temperature service and achieves its characteristic high strength through a precipitation aging heat treatment that forms strengthening phases within the austenitic matrix. The sluggish precipitation hardening response allows the alloy to be readily welded without hardening or cracking. Alloy 718 maintains high strength and good ductility up to 704°C (1,300°F) with oxidation resistance to 982°C (1,800°F), and also exhibits excellent tensile and impact strength at cryogenic temperatures.

Composition per ASTM B670 / AMS 5596 requirements.

Actual properties depend on product form, dimensions, heat-treatment cycle, and the specified standard.

Solution Annealed (AMS 5596 / ASTM B670)

Material is normally supplied in the solution annealed condition. Solution treatment temperature: 1,725°F – 1,850°F (940–1,010°C) followed by air cooling. Recommended when the material requires forming, welding or rough machining. Typical tensile strength: 120 – 140 ksi (830 – 965 MPa).

Solution Annealed and Aged (AMS 5597)

Used when the finished component requires the characteristic high strength of Alloy 718. A commonly used aging cycle includes holding at 1,325±25°F (718±14°C) for 8 hours, furnace cooling at approximately 100°F/hr to 1,150±25°F (621±14°C), holding for a total aging time of 18 hours, and final air cooling.

Typical aged properties per ASTM B670: tensile strength 180 ksi (1,241 MPa) minimum, yield strength 150 ksi (1,034 MPa) minimum, elongation 12% minimum.

Alloy 718 provides excellent resistance to chloride stress corrosion cracking and general corrosion in many oil and gas and chemical environments. The additions of niobium and molybdenum, along with aluminum and titanium, result in excellent corrosion resistance in oil and gas applications and high strength properties.

Key Corrosion Characteristics:

• Resistant to chloride stress-corrosion cracking
• Good oxidation resistance up to 982°C (1,800°F)
• Good resistance to many aqueous and chemical environments
• Excellent fatigue and creep-rupture resistance at elevated temperatures
• Good weldability without post-weld cracking

Selection Considerations:

• Provides useful resistance in many chloride-containing environments
• Not immune to pitting or crevice corrosion in all conditions
• For aggressive acid service, Alloy 625, C-276 or Alloy 22 may be preferable
• Final selection must consider medium, concentration, temperature, pressure and oxidizing or reducing conditions
• NACE MR0175 / ISO 15156 compliance is not automatic – depends on controlled chemistry, heat treatment, hardness and environmental verification

• Aerospace: Gas turbine components, aircraft engine parts, thrust reversers, exhaust ducts, structural panels
• Oil and Gas: Downhole tools, wellhead components, subsea equipment, valves
• Power Generation: Land-based turbine engines, nuclear reactor components
• Industrial: Heat exchanger plates, pressure vessels, storage tanks, offshore platform components
• Cryogenic Applications: Components operating at -200°C

Available quality-control services include:

• Heat-number traceability
• Chemical composition verification
• Tensile, yield and elongation testing
• Hardness inspection
• Dimensional and surface inspection
• Positive Material Identification (PMI)
• Ultrasonic testing
• Dye penetrant inspection
• Heat-treatment records
• EN 10204 3.1 material certificate

PMI can identify major alloying elements but cannot independently verify carbon content, heat-treatment condition, mechanical properties or NACE compliance.

For an accurate quotation, please provide:

Alloy Grade · Standard · Product Form · Dimensions (Thickness × Width × Length) · Quantity · Heat Treatment · Inspection Requirement · Application · Working Temperature · Destination Port

For corrosive or sour-service projects, also provide:

Chemical Medium · Concentration · Pressure · Chloride Content · H₂S Conditions · Oxidizing or Reducing Environment

• Request ASTM B670 Alloy 718 Plate Quote
• Upload Drawing or MTO
• Check Available Stock
• Ask for Alloy Selection Support

1. What is ASTM B670 Alloy 718 plate?

ASTM B670 Alloy 718 plate (UNS N07718) is a precipitation-hardenable nickel-chromium alloy plate designed for high-temperature service with high tensile strength, creep resistance, and oxidation resistance up to 982°C.

2. What are the UNS and EN numbers for Alloy 718?

The UNS designation is N07718; the European Werkstoff number is 2.4668; the EN material symbol is NiCr19Fe19Nb5Mo3.

3. Which standard applies to Alloy 718 plate?

ASTM B670 / ASME SB-670 and AMS 5596 apply to Alloy 718 plate, sheet and strip. For bar and forgings, ASTM B637 applies.

4. What thickness range is available for ASTM B670 plate?

Stock thickness ranges from 5 mm to 50 mm, with widths up to 1,250 mm and lengths up to 2,500 mm.

5. Does Alloy 718 plate require heat treatment?

Yes. Full strength is developed through precipitation aging. ASTM B670 specifies the material is supplied in the annealed condition, but must be capable of meeting mechanical properties after precipitation hardening.

6. What is the typical aging cycle for Alloy 718?

A typical aging cycle is 1,325°F (718°C) for 8 hours, furnace cool to 1,150°F (621°C), hold for total 18 hours, air cool.

7. What are the typical mechanical properties of aged Alloy 718?

In the aged condition, tensile strength is 180 ksi (1,241 MPa) minimum, yield strength is 150 ksi (1,034 MPa) minimum, and elongation is 12% minimum.

8. What is the maximum service temperature for Alloy 718?

Alloy 718 maintains high strength to 704°C (1,300°F) and offers oxidation resistance up to 982°C (1,800°F).

9. Can Alloy 718 plate be welded?

Yes. Alloy 718 exhibits good weldability and resistance to post-weld cracking. Welding should be performed in the solution-annealed condition using qualified welding procedures.

10. What information is required for a quotation?

Please provide the standard (ASTM B670), product form (plate), thickness, width, length, quantity, heat-treatment condition, inspection requirements, application, working temperature and destination port.