17-4PH
17-4PH
(OP)
this material can have so many heat treat conditions. H900, H1025, H1100........
i have one very small part, H-1025. i checked HRc, it reaches 44, higher than AMS spec. but as you know HRc is just for reference, not a base for rejection. (tensile listed as minimum)
what other metallurgical way to nail down the heat treat condition, as H-1025 relative lager elongation is critical to my application.
thanks.
i have one very small part, H-1025. i checked HRc, it reaches 44, higher than AMS spec. but as you know HRc is just for reference, not a base for rejection. (tensile listed as minimum)
what other metallurgical way to nail down the heat treat condition, as H-1025 relative lager elongation is critical to my application.
thanks.





RE: 17-4PH
RE: 17-4PH
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P.E. Metallurgy, Plymouth Tube
RE: 17-4PH
RE: 17-4PH
For every batch of heat treat and material heat lot you may get different hardness results. Therefore, when you specify standard heat treatment of H-1025 do not expect strict hardness results. If you ask for hardness then the heat treatment is not standard and is not guarantied by the spec.
RE: 17-4PH
For strip and plate:
AMS 5604E specifies 35-42HRC
ASTM A693: <.1875'' 35-43, .1875-4.0'' 33-42
For bar:
AMS 5643 34-42 (hardness is not a basis for rejection)
ASTM A564, A705 MIN 35HRC
There are complicated HT, but the tendency is pretty clear: as the aging temperatures increase, hardness, tensile, yield decrease, while elongation, impact strength increase.
when hardness=44hrc, the aging temperature was probably lower than 1025F.
RE: 17-4PH
We always used both strength and temperature in our spec (not AMS restricted).
If the material was on the high side of the strength we would re-age at a higher temp.
We were looking to meet a min. strength and get maximum toughness.
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P.E. Metallurgy, Plymouth Tube
RE: 17-4PH
right?
RE: 17-4PH
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P.E. Metallurgy, Plymouth Tube
RE: 17-4PH
RE: 17-4PH
However you need to be careful to not jump to conclusions.
Given the tolerance in aging temperature, and how steep the strength vs temperature curves are in this region you could easily get a change. Say the original aging was at 1015, and you re-age at 1035. Based on published cures that should produce a change of 3-4 points RC.
But if you re-age and can assure that parts never exceed 1025, and you get more than a 5 point drop then I would be concerned.
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P.E. Metallurgy, Plymouth Tube
RE: 17-4PH
AMS5643, table 2. "elongation in 4D".
what 4D stands for?
thanks.
RE: 17-4PH
so a strip specimen (dog bone), elongation in 2'' or 4W is used. w = width of strip.
RE: 17-4PH