Steel HT properties MIL standards

[GDfern]

I had a request from a vendor to change part made from 15-5 Steel AMS 5659 with (H1025) to 17-4PH AMS 5659 with Heat treat as per AMS 2759/3. I am in structural engineering side and wanted to compare static and fatigue properties. When I requested from the vendor about temper cond. I was told it is per AMS 2759/3 without saying whether its H900 or H1025. How am I going to find out temper properties using AMS 2759/3?
Thanks

 

[metengr]

To correctly find out the temper condition, you need to know the strength of the material as-received. The strength should be on the test report received from the supplier or mill. Why was the material change made without this comparison performed initially?

 

[EdStainless]

Look up the min properties for the 15-5PH H1025, and then look for which temp will give you the same SPEC MIM (not actual or typical) properties for 17-4PH.
You may need to look in the MMPDS also to verify the allowed design stress for each condition.
Though this isn't your problem, the person specifying this is responsible for this decision. They need to call out a condition in order for their order to be valid. Just tell them that critical information is missing and you will make parts as soon as they can provide it.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube

 

[WKTaylor]

GDFern... perhaps You made a mistake in material spec...

Quote...
"I had a request from a vendor to change part made from 15-5 Steel AMS 5659 with (H1025) to 17-4PH AMS 5659 with Heat treat as per AMS 2759/3...".
unquote.

AMS5659 Steel, Corrosion-Resistant, Bars, Wire, Forgings, Rings, and Extrusions 15Cr - 4.5Ni - 0.30Cb (Nb) - 3.5Cu - UNS S15500 >>>> IS ONLY FOR 15-5PH CRES.

There are [2] similar AMS specs for 17-4PH CRES

AMS 5643 Steel, Corrosion-Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb (Nb) - 4.0Cu Solution Heat Treated, Precipitation Hardenable - UNS S17400 >>> IS ONLY FOR 17-4PH... and is the 'preferred alloy per MMPDS for these forms

A lesser specified alloy/spec [I don't have any mechanical data for this spec] is...

AMS5622 Steel, Corrosion-Resistant, Bars, Wire, Forgings, Tubing, and Rings 16Cr - 4.0Ni - 0.30Cb - 4.0Cu Solution Heat Treated, Precipitation Hardenable Consumable Electrode Remelted - UNS S17400

bait-and-switch?

NOTE. My company prefers 15-5PH over 17-4PH due to better toughness and better availability in thick sections.

Regards, Wil Taylor

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