Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
(OP)
Guys...
In the late 2000s we [process/liaison/design engineers] were prohibited from specifying 15-5PH CRES sheet per AMS5862 due to inner-laminar defects/issues. As far as I'm aware, this 'prohibition' RE 15-5PH CRES sheet [material less than 0.187 thick] is still in-effect.
Apparently, when the vendor was rolling the billet-to-plate-to-sheet thicknesses they were introducing laminar discontinuities that were hard to detect. These defects were uncovered [my company/industry] when 'simple' formed parts failed during/just after forming and/or PHT. The word on the street was the OEM for this material was 'un-convinced' a problem existed and suggested sheet stock be 100% US-NDI inspected, if necessary. Some senior M&P engineers suggested this 'take-it or leave-it, no-matter-us' attitude by the vendor is what provoked the prohibition.
Please advise: is 15-5PH CRES sheet still exhibiting potential laminar problems... Or is this old news?
In the late 2000s we [process/liaison/design engineers] were prohibited from specifying 15-5PH CRES sheet per AMS5862 due to inner-laminar defects/issues. As far as I'm aware, this 'prohibition' RE 15-5PH CRES sheet [material less than 0.187 thick] is still in-effect.
Apparently, when the vendor was rolling the billet-to-plate-to-sheet thicknesses they were introducing laminar discontinuities that were hard to detect. These defects were uncovered [my company/industry] when 'simple' formed parts failed during/just after forming and/or PHT. The word on the street was the OEM for this material was 'un-convinced' a problem existed and suggested sheet stock be 100% US-NDI inspected, if necessary. Some senior M&P engineers suggested this 'take-it or leave-it, no-matter-us' attitude by the vendor is what provoked the prohibition.
Please advise: is 15-5PH CRES sheet still exhibiting potential laminar problems... Or is this old news?
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]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]





RE: Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
RE: Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
So unless you were using this spec in order to get re-melted material (and not go to the trouble of ordering remelted 17-4) I am not sure why someone would use 15-5 at light gage.
We were doing a heavy wall tube job some years ago in 15-5PH (3" OD x 1" wall). We annealed the billets, then aged them, then re-annealed them prior to extrusion. This gave us some grain refinement and better uniformity. Every time you age and re-anneal 15-5 or 17-4 the grain size gets finer and more uniform, which improves toughness with only a very slight loss of strength.
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P.E. Metallurgy, Plymouth Tube
RE: Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
Still the question remains: is 15-5PH CRES sheet per AMS5862 available today? IF so are there any remaining industry concerns [use without restrictions [US-NDI] or other prohibitions]?
Background, NOTE.
15-5PH Sheet was specified for most sheet metal PHT CRES part applications on my Acft when it under-went 2-significant/unique structural modifications starting in the 1980s.
Unsure as to exactly 'why' this occurred... but it was assumed by other M&P engineers that the 15-5PH was perceived to have 'slightly better properties over-all in the 1970s'... especially at H9xx PHT relative to 17-4PH... and... it was listed in a modification working document... M&P 'design cookbook', written in 1978... as the 'preferred PHT CRES for sheet metal' parts.
OH Yeah... and that same M&P 'cookbook' said it was ok to design to H900 [HT180]... which is generally considered NOT advisable today [poor SCC, low fracture toughness].
NOTE.
The ONLY acceptable applications for 15-5PH CRES H900, today, appears to be for: (a) bushings and (b) certain mechanical parts fully stress relieved after all machining operations, in-prep for finishes.
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]
o Unfortunately, in science what You 'believe' is irrelevant. ["Orion", Homebuiltairplanes.com forum]
RE: Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
In straight AOD I have see such things, but never in remelt.
Generally I approach PH stainless like this;
-Can you use AOD 17-4PH?
-If you need more formability look at 17-7PH
-If you have thicker parts look at 15-5PH
-If you need better toughness mover to remelted 13-8PH
And if you really need higher strength and can sacrifice toughness there is always C-465
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P.E. Metallurgy, Plymouth Tube
RE: Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
Interesting, learned something again. Star for that, Ed.
RE: Quality problems still an issue for 15-5PH CRES sheet per AMS5862?
: Yes, we offer Strip and plate products to AMS 5862. Yet, the more common spec. is AMS 5659.