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View Full Version : can 6082T6 aluminium be annealed and still be strong



SheerGold
09-25-2012, 12:27 PM
I want to put a 25 degree bend in a 300cm length of aluminium grade 6082T2.

It's cross section dimensions are 2 inch by 0.5 inch (5.08cm x 1.27cm).

The bend need not be sharp, but can occur over 2 cm.

Will it need to be annealed before bending? And if so, how much annealing would be required?

I don't have a workshop, just ordinary tools. The only source of heat would be to put it on the gas cooker hob. It is just gas cooker hob. There is no oven.

I also have a small propane torch (the kind used by gas fitters). But that would not burn for long.

I would be holding the aluminium with a heavy duty G-clamp, and applying the bending force with another heavy duty G-clamp. I don't have anything else suitable to bend it with.

Also, if annealing is required, is it possible to do that in such a way that the strength is not reduced dramatically.

All advice is welcome.

bobw53
09-25-2012, 01:53 PM
It'll come back up to a T4 just sitting at room temp for 3 days or so, that will get you back to 65% or so of the original strength.

Good thing is that aluminum is easy to heat treat, just toss it in the oven for 4 hours or so at about 400. Let it air cool.
Look up the specifics for the alloy though, I've seen some heat treats that go for 18 hours, but generally 4 hours at 400 will get you there.

As a funny, we had a customer that had some parts annealed and formed, then they needed to come back to a T4, they paid us
to heat treat it, they knew that we just let it sit for 3 days, but they wanted the paperwork to prove it. Had to send my
calendar out for certification.

michigan doug
09-25-2012, 05:39 PM
What's it for? If it's for rebuilding some airplane landing gear, I'm going to warn you away from it. If it's something more mundane, I'm going to encourage you to press on and to post pictures when it's done.

finest regards,

doug

Lew Hartswick
09-25-2012, 05:40 PM
< they knew that we just let it sit for 3 days, but they wanted the paperwork to prove it. Had to send my
calendar out for certification. >

I think that is the first time I've ever heard of certifying a calendar. :-) Be careful
not to use the "Procrastinators" organization to do have it done.
...lew...

Dr Stan
09-25-2012, 09:13 PM
As a funny, we had a customer that had some parts annealed and formed, then they needed to come back to a T4, they paid us to heat treat it, they knew that we just let it sit for 3 days, but they wanted the paperwork to prove it. Had to send my
calendar out for certification.

I have used certified tape measure (no joke), but never a calendar. BTW, paper or digital version? :)

LKeithR
09-26-2012, 12:30 PM
I have used certified tape measure (no joke), but never a calendar. BTW, paper or digital version? :)

A customer of ours builds inflatable boats. The got a contract to build several for the Canadian Forces and yup, you guessed it, they had to have a tape measure certified by Measurement Canada. Certain dimensions had to be verified by the "master" tape. For everything else they could use a regular tape that was checked against the master. If I remember right it cost them 700-800 bucks to have the darn thing certified. Everything charged back to the customer (taxpayer)--talk about government waste...

Evan
09-26-2012, 12:51 PM
The T2 grade means it was heated for shaping, then cooled and then further cold worked. If you heat it for bending it will come back to that temper naturally only if cold worked. It is essential to heat to the correct temperature. Too high can destroy the properties. If the project depends on the exact properties then do not proceed. For example, if a part must be welded and isn't re heat treated (which may be done once) then it must be considered as annealed even though it will regain some strength.

This chart shows what to expect from aluminum that has been annealed. AW stands for "As Welded" with no further treatment. PWA means Post Weld Aged. That means artificial aging by heating to a specific temperature and then allowed to sit for at least a week. The T2 designation also assumes that the part has been cold worked so that grade cannot be reached by simply aging. The aluminum stock is heated while rolling the billet and then cold worked by further rolling and possible stretching the plate.

http://ixian.ca/pics9/alweld.jpg

rowbare
09-27-2012, 11:35 AM
A customer of ours builds inflatable boats. The got a contract to build several for the Canadian Forces and yup, you guessed it, they had to have a tape measure certified by Measurement Canada. Certain dimensions had to be verified by the "master" tape. For everything else they could use a regular tape that was checked against the master. If I remember right it cost them 700-800 bucks to have the darn thing certified. Everything charged back to the customer (taxpayer)--talk about government waste...
Expensive yes; a waste, probably not. Remember that nearly everything the military buys is part of a system and it is very important that things fit together the way they are supposed to. When it is zero dark thirty in a storm at sea people don't need to be trying to figure out why the Meglinator doesn't fit.

bob