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Old 10-11-2018, 12:26 PM
crystallographic crystallographic is offline
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Default annealing metal alloys - 6061, done in the field

Quote:
Originally Posted by fciron View Post
Kent, are you saying that 6061 can be annealed but it will age harden again in 12 to 18 hours?

Just want to be sure I understand you correctly.

"Annealing" is a procedure done to soften metals with correct heating to correct temperatures, holding for a correct amount of time, and quenching at a given rate.

Different metal alloys require different annealing procedures, correctly done.


For full anneal, heat-treatable aluminum alloys must be taken to 925F, held to soak completely and then the temp. is lowered 50deg F per hour until 350F is reached, and then the part may be cooled in any fashion. This is how to get a full anneal on alloy 6061, as well as 2024, 2019, 2117, 7075, 6063, 6153, and etc.
Annealing this family of aluminum alloys requires a controlled environment.


"In the field", outside of the controlled environments, the craftsman can only do a "partial, temporary anneal" - which is to take his part to 650F and then quench. And, yes, precipitation hardening takes over and brings the part roughly back to "hard" in 24-36 hours.
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