Experience with AMS 6424 (4350M)

[EdStainless]

Is anyone out there familiar with working with this alloy?
This is one of those odd old MIL spec alloys.
Any advice?

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P.E. Metallurgy, Plymouth Tube

 

[MagBen]

ED, very rare seeing you post a question! we make a similar HSLA 4335. What kinds of advice you are looking for?

 

[EdStainless]

Does anyone make it?
How difficult is it to work with?
I know, at 50 points C it can get brittle (anyone say quench cracking) but it is a interesting chemistry.
0.50 C
0.80 Cr
1.80 Ni
0.25 Mo

It will have a CE of over 0.90

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P.E. Metallurgy, Plymouth Tube

 

[MagBen]

.5% C is not a problem to work with (forging, cold work etc) when it is annealed. It does exist a tempered martensitic embrittlement ((>55RC) when tempered at 500F where there is zero retained austentic. .4% C (4340) is more popular because it has a much higher/more reliable toughness while without sacrificing significant strength. At a given hardness (tensile), 4340 always has higher charpy impacts than 4350.

If you really like the high strength of 4350, low temper temperature (about 400F) with some percentage of retained austenite is recommended.

 

[EdStainless]

These are replacement parts for a military application.
The 6424 is the speced material and there is no chance for an alternate.
I don't know what the final HT condition is.
We will supply it in the annealed condition.

Our issues are related to our ability to hot pierce hollows and cold draw tubes.
And of course we need to find a source for material.

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P.E. Metallurgy, Plymouth Tube

 

[WKTaylor]

Have You checked with the company that manages the Aerospace Structural Metals Database[ASMD]?

https://cindasdata.com/products/asmd

Is this for ordnance?

Regards, Wil Taylor

o Trust - But Verify!
o We believe to be true what we prefer to be true. [Unknown]
o For those who believe, no proof is required; for those who cannot believe, no proof is possible. [variation,Stuart Chase]
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[Maui]

Ed, give Castle Metals a call. Their website says that their 4350 is currently out of stock, but one of their warehouses may have some yet. Their website is here:

https://www.castlemetals.com/

Maui

 

[EdStainless]

I believe that it is a tank part.
Thanks Maui, I'll check with Castle.

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P.E. Metallurgy, Plymouth Tube