SS PH15-5 and Cond. A in MIL-HDBK-5 2

[bbahavar]

MIL-HDBK-5 says that a part in SS PH15-5 should never be used in condition A. What is the reason? Is it related to stress-corrosion cracking? Thanks, Ben bahavar

 

[Neubaten]

Why would you want to use a Precipitation Hardened steel in a non precipitated condition?

 

[RPstress]

Thread thread330-243608 in the metallurgy forum has some background that's relevant, albeit as a result of some confusion between 17-4 (which is similar to 15-5 in many ways) and 17-7.

The Aerospace Structural Metals Handbook (ASMH) says that the elongation in condition A is 3% minimum. Essentially for 15-5PH (and 17-4PH) condition A can be brittle, with a 180 degree bend rad of 18t.

Other data in the ASMH indicates that condition A is a bit better than conditions H900 and H925 for stress corrosion cracking and toughness.

It would pay to get the opinion of an actual metallurgist.

 

[bbahavar]

An engineer who is no longer avaiable had recommended that this be done!

 

[monkeydog]

So is this the engineer who will be blamed, or the engineer that recommended a metallurgist be brought in?