Inconel 718 – Composition, Properties and Applications of Inconel 718 Nickel-Chromium Alloy by Alloy Wire International

Topics Covered

Background

Inconel 718 – Nickel-Chromium Alloy

Chemical Composition of Inconel 718

Typical Properties of Inconel 718

Properties of Supplied Materials and Heat Treated Materials

Relevant Standards

Equivalent Materials

Applications of Inconel 718

Background

Alloy Wire International Ltd. is a U.K. wire manufacturer specialising in the production of high performance alloys, mainly Nickel Alloys, but including Cobalt and Titanium Alloys.

These alloys might be used in any environment that requires resistance to heat and corrosion but where the mechanical properties of the metal must be retained.

Inconel 718 – Nickel-Chromium Alloy

Inconel 718 is a Nickel-Chromium alloy being precipitation hardenable and having high creep-rupture strength at high temperatures to about 700°C (1290°F). It has higher strength than Inconel X-750 and better mechanical properties at lower temperatures than Nimonic 90 and Inconel X-750.

Chemical Composition of Inconel 718

The compositional range for Inconel 718 is provided in the table below.

Element

Content

Ni+Co

50 - 55 %

Cr

17 - 21 %

Fe

BAL

Nb+Ta

4.75 - 5.5 %

Mo

2.8 - 3.3 %

Ti

0.65 - 1.15 %

Al

0.2 - 0.8 %

Typical Properties of Inconel 718

Typical properties of Inconel 718 are covered in the following table.

Property

Metric

Imperial

Density

8.19 g/cm3

0.296 lb/in3

Melting point

1336 °C

2437 °F

Co-Efficient of Expansion

13.0 µm/m.°C
(20-100 °C)

7.2x10-6 in/in.°F
(70-212 °F)

Modulus of rigidity

77.2 kN/mm2

11197 ksi

Modulus of elasticity

204.9 kN/mm2

29719 ksi

Properties of Supplied Materials and Heat Treated Materials

Condition of Supply

Heat Treatment (After Forming)

No.1 Spring Temper/Spring Temper

1. Solution Anneal at 980°C (1800°F) for 1 hour and air cool and

2. Age harden at 720°C (1330°F) for 8 hours and furnace cool to 620°C (1150°F) and hold at 620°C (1150°F) for a total age hardening time of 18 hours and air cool.

No.1 Spring Temper/Spring Temper (NACE MRO175)

1. 1010°C (1870°F) 2 hours and air cool and

2. 790°C (1455°F) 6 hours and air cool.

Condition

Approx Tensile Strength

Approx Service Temp.

Annealed

800 - 1000 N/mm2

116 - 145 ksi

-

No.1 Spring Temper

1000 - 1200 N/mm2

145 - 175 ksi

-

No.1 Spring Temper + Annealed + Aged

1250 - 1450 N/mm2

181 - 210 ksi

-200 to +550°C

-330 to +1020°F

Spring Temper

1300 - 1500 N/mm2

189 - 218 ksi

-

Spring Temper + Annealed + Aged

1250 - 1450 N/mm2

181 - 210 ksi

-200 to +550°C

-330 to +1020°F

Relevant Standards

Inconel 718 is covered by the following standards:

         AMS 5663

         AMS 5832

         AMS 5962

         AMS 5662

         ASTM B637

Equivalent Materials

Inconel 718 is the tradename of Special Metals Group of Companies and equivalent to:

         W.NR 2.4668

         UNS N07718

         AWS 013

Applications of Inconel 718

Inconel 718 typically finds application in:

         Gas turbines

         Rocket motors

         Space craft

         Nuclear reactors and pumps.

 

 

Source: Alloy Wire International

 

For more information on this source please visit Alloy Wire International.

 

Date Added: May 2, 2008 | Updated: Jun 11, 2013
Comments
  1. SA Rizvi SA Rizvi India says:

    I want to confirm whether IN 718 is a ferrous or non ferrous material?
    saritbhu@gmail.com

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of AZoM.com.
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