17-4 Annealed vs H1100

[capntom62]

We have manufactured some parts using 17-4 in the as-purchased Annealed condition. Upon paperwork review, it was discovered that the customer blueprint required the H1100 condition. Uh oh, can we do anything or are they that much different ? The parts have been shipped.
They are small stampings.

 

[metengr]

You should review this document for background information;

https://www.aksteel.com/sites/default/files/2018-01/174ph201706.pdf

Yes, the A condition is very different (wide range of tensile properties) in comparison to the specified H1100 heat treatment, which provides specified tensile properties.

 

[EdStainless]

You should not use 17-4 in the annealed condition, the properties are highly variable and the toughness is very poor.
After making the parts you should have had them aged at 1000F in order to meet the requirements.
All of these parts should be returned.

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P.E. Metallurgy, Plymouth Tube

 

[shu60]

Armco, the original developer of this alloy, warned against using it in Cond. A (as you call annealed) especially in bar and larger section sizes. However, subsequent testing showed this condition did not have "bad" properties and had strength similar to H1100. Since these are small stampings, adequate toughness is "probably" present. If Cond. A properties were included with the certification, you could tell if the strength/ductility were adequate. Nevertheless, you are out of spec since it's not in the H1100 condition. This could be rectified by giving the parts 1100F for 4 hrs + air cool, since this would be the typical practice anyway. If not done in a vacuum furnace or in inert atmosphere, the heat tint would have to be removed.