COMPANY HEADER
Print Back
Inconel® Alloy 718 (UNS N07718) Ni 52.5, Cr 19.0 Fe 18.5 Mo 3.0 Nb+Ta 3.6

Excellent strength from -423 ºF to 1300 ºF (-253 ºC to 705 ºC). Age hardenable and may be welded in fully aged condition, excellent oxidation resistance up to 1800 ºF (980 ºC).
Jet engines, pump bodies and parts, rocket motors and thrust reversers, nuclear fuel element spacers, hot extrusion tooling.

Gamma Prime strengthened alloy with excellent mechanical properties at elevated temperatures, as well as cryogenic temperatures. Suitable for temperatures up to around 1300 ºF. Can be readily worked and age hardened.
Unit of Measure

Specifications

Type

N/A Bar

Size

N/A 2.000 in

Alloy

N/A 718

Physical

Density

N/A 0.296 lb/in³

Specific Heat

N/A 0.104 Btu/lb ºF

Electrical Resistivity

N/A Aged: 725 ohm/cir-mil-ftAnnealed: 753 ohm/cir-mil-ft

Curie Temperature

N/A Aged: -170 ºFAnnealed: <-320 ºF

Melting Range

N/A 2300 to 2437 ºF

Thermal Expansion Coefficient at 70 to 200 Degree Fahrenheit (ºF)

N/A 7.1 x 10-6 in/in/ºF

Mechanical

Mechanical Type

N/A Aged Annealed

Tensile Strength

N/A Aged: 180 ksiAnnealed: 125000 psi

Yield Strength

N/A Aged: 150 ksiAnnealed: 60000 psi

Elongation

N/A Aged: 12 %Annealed: 51 %

Hardness

N/A Annealed: Rc 36 Annealed: Equivalent Aged: C36

Nominal Chemistry

Minimum Nickel (Ni)

N/A 52.5

Iron (Fe)

N/A Balanced

Chromium (Cr)

N/A 19

Maximum Cobalt (Co)

N/A 1

Molybdenum (Mo)

N/A 3

Maximum Copper (Cu)

N/A 0.30

Aluminum (Al)

N/A 0.5

Maximum Manganese (Mn)

N/A 0.35

Maximum Silicon (Si)

N/A 0.35

Titanium (Ti)

N/A 0.9

Carbon (C)

N/A 0.05

Other

N/A 5 Cb + Ta

General Resistance

General Resistance

N/A Temperature Oxidation Corrosion

Unified Numbering System (UNS)

N/A N07718

Werkstof

N/A 2.4668

Sheet/Plate USA

N/A Aged: AMS 5596 Aged: B670 Annealed: AMS 5596 Annealed: B670

Bar/Rod USA

N/A Aged: B637 Aged: AMS 5663 Aged: AMS 5664 Annealed: AMS 5662 Annealed: B637

Forging USA

N/A Aged: B637 Aged: AMS 5663 Aged: AMS 5664 Aged: AMS 5832 Annealed: B637 Annealed: AMS 5662

Weld Wire

N/A A5.14 ERNiFeCr-2

Machinability Ratings

Speed Surface

N/A Aged: 40 ft/mmAnnealed: 20 ft/mm

Speed Percent (%) of B1112

N/A Aged: 24 Annealed: 12

Note

N/A These machinability ratios must be recognized as approximate values. They are a reasonable guide to relative tool life and lower required for cutting. It is obvious, however, that variables of speed, cutting oil, feed and depth of cut will significantly affect these ratios.

Machining Section

N/A The alloys described here work harden rapidly during machining and require more power to cut than do the plain carbon steels. The metal is 'gummy', with chips that tend to be stringy and tough. Machine tools should be rigid and used to no more than 75% of their rated capacity. Both work piece and tool should be held rigidly; tool overhang should be minimized. Rigidity is particularly important when machining titanium, as titanium has a much lower modulus of elasticity than either steel or nickel alloys. Slender work pieces of titanium tend to deflect under tool pressures causing chatter, tool rubbing and tolerance problems.

Make sure that tools are always sharp. Change to sharpened tools at regular intervals rather than out of necessity. Titanium chips in particular tend to gall and weld to the tool cutting edges, speeding up tool wear and failure. Remember- cutting edges, particularly throw-away inserts, are expendable. Don't trade dollars in machine time for pennies in tool cost.

Feed rate should be high enough to ensure that the tool cutting edge is getting under the previous cut thus avoiding work-hardened zones. Slow speeds are generally required with heavy cuts. Sulfur chlorinated petroleum oil lubricants are suggested for all alloys but titanium. Such lubricants may be thinned with paraffin oil for finish cuts at higher speeds. The tool should not ride on the work piece as this will work harden the material and result in early tool dulling or breakage. Use an air jet directed on the tool when dry cutting, to significantly increase tool life.

Lubricants or cutting fluids for titanium should be carefully selected. Do not use fluids containing chlorine or other halogens (fluorine, bromine or iodine), in order to avoid risk of corrosion problems. The speeds are for single point turning operations using high speed steel tools. This information is provided as a guide to relative machinability, higher speeds are used with carbide tooling.

Applications

N/A Uses for this alloy tend to be in the field of gas turbine components and cryogenic storage tanks. Jet engines, pump bodies and parts, rocket motors and thrust reversers, nuclear fuel element spacers, hot extrusion tooling. Other popular uses are high strength bolting, and down hole shafting.

Additional Information

Additional Information

N/A Excellent strength from -423 ºF to 1300 ºF (-253 ºC to 705 ºC). Age hardenable and may be welded in fully aged condition, Excellent oxidation resistance up to 1800 ºF (980 ºC). Typically sold in the solution annealed temper, but can be ordered aged, cold worked, or cold worked & aged.