Full Transcript:

What’s up guys? This is Michael with Michael Talks Metal back for another session on some Inconel. Today we will be taking a look at another of the more popular of the precipitation hardening Nickel alloys. Known as Inconel X-750 when produced  by Special Metals Corporation or just ” alloy X-750 ” when produced by other manufacturers, the UNS chemical composition designation is N07750.

With a combination of high strength, corrosion, and oxidation resistance it has applications from minus 423 deg F to 1300 deg F.  Higher temperature applications result in over-aging, but have useful strength for limited applications.

This alloy is typically strengthened by a multiple step heat treatment. First, the alloy is solution treated followed by a stabilizing treatment and then a precipitation heat treat treatment. Depending on the application and properties required, the heat treatments vary in temperatures, holding times, and cooling methods.

Applications in aerospace  include  rocket engine thrust chambers and jet engine and gas turbine rotors. At cryogenic temperatures it is used in a variety of components.

X-750 is approved for NACE oil field applications with appropriate heat treatment.

Curie temperature is below minus 100 deg F in all conditions for non-magnetic applications.

Room temperature permeability in the hot rolled condition is 1.0020 at 200 oersted.

Chemical composition UNS 07750

Nickel (plus cobalt) …………………………………..   70.00 %  minimum

Chromium ……………………………………………….   14.00  –  17.00 %

Iron ………………………………………………………..    5.0  –  9.0 %

Niobium (plus Tantalum) ……………………………    0.70  –  1.20 %

Aluminum ………………………………………………..    0.40  –  1.00 %

Titanium …………………………………………………..   2.25  –  2.75 %

Carbon …………………………………………………….   0.08 % maximum

Manganese ………………………………………………   1.00 % maximum

Sulfur ……………………………………………………….   0. 01 % maximum

Silicon………………………………………………………    0.50 % maximum

Copper ……………………………………………………..   0.50 % maximum

Cobalt………………………………………………………..  1.00 % maximum

Room temperature  minimum mechanical properties depend on product and heat treatment. Typical range for a precipitation hardened condition

Yield strength  100,000  – 115,000 psi

Tensile strength  155,000   –  170,000  psi ,

Elongation 15 %

Density is  point 299 lbs per cubic inch

Specifications:

Bars and Forgings: 

AMS 5667, AMS 5668, AMS 5669, AMS 5670, AMS 5671

AMS 5747

ASTM B 637    ASME SB 637

Sheet and Plate:

AMS 5542, AMS 5598

Each specification has requirements that can add to or restrict the chemical composition beyond what we have shown you today.

Premium vacuum melting  or multiple melting cycles are often required in X-750 specifications.

Heat treatment and other processing and testing requirements also exist within the individual specifications.

So to be sure that all requirements have been identified.

I will remind you to ….check the specs…..Thanks for tuning in, this is Michael with Michael Talks Metal. If you have made it this far and haven’t subscribed, please do so now. If you have missed any previous videos click here to catch up. Thanks again for watching. See you next Thursday!