Sparweb
Aerospace
- May 21, 2003
- 5,172
I'm trying to pin down a specific process for this. Not coming up with a spec for it in the AMS or ASTM catalogues that I am searching.
For a long time I haven't worried about the terminology much. It seemed pretty obvious to me that "solution heat treated" CRES 321 tubing was equivalent to annealed, or close enough. Now I have a purchaser that questions me on the details, and it does make me wonder, is there a difference? Or is it just a semantic question? I can find detailed processes for solution heat-treatment of aluminum alloys, and for precipitation-hardened stainless alloys. Why am I missing a SHT process spec for austentitic alloys like 321?
I have read specs from AMS (such as AMS 5557) which call for "solution heat treatment" of the materials, and I've read through the heat treatment spec's like AMS 2759 (and the sub-chapter 2759/4 for austentitic steels) which don't say "solution heat treatment", but do define "annealing" in detail. AMS 5557 does not say to heat treat per AMS2759 - in fact is doesn't offer a specific process for SHT at all. So what is it, exactly?
Seems like they guys at SAE have missed something. They also don't offer any definition of "pickling" or "passivation" which really seems to leave the final condition of the material unclear, now.
STF
For a long time I haven't worried about the terminology much. It seemed pretty obvious to me that "solution heat treated" CRES 321 tubing was equivalent to annealed, or close enough. Now I have a purchaser that questions me on the details, and it does make me wonder, is there a difference? Or is it just a semantic question? I can find detailed processes for solution heat-treatment of aluminum alloys, and for precipitation-hardened stainless alloys. Why am I missing a SHT process spec for austentitic alloys like 321?
I have read specs from AMS (such as AMS 5557) which call for "solution heat treatment" of the materials, and I've read through the heat treatment spec's like AMS 2759 (and the sub-chapter 2759/4 for austentitic steels) which don't say "solution heat treatment", but do define "annealing" in detail. AMS 5557 does not say to heat treat per AMS2759 - in fact is doesn't offer a specific process for SHT at all. So what is it, exactly?
Seems like they guys at SAE have missed something. They also don't offer any definition of "pickling" or "passivation" which really seems to leave the final condition of the material unclear, now.
STF