Need some help from you guys. Im working on writing weld procedures at work for gmaw and gtaw aluminum so that I can send them off for testing to certify the procedure. the problem that im running in to is that the gtaw works great and bent with no problem. but the gmaw breaks almost every time. I am using 4043 filler that is for 6000 grade aluminum, letting the coupons cool completely, then cleaning and bending. Even made sure to round all the corners and weld the pieces together with the grain running the same direction. Does anyone know the process for annealing 6061 or have any suggestions. If this is already in another thread I apologize I just haven't found anything.

What shield gas are you using? 

GTAW use 100% Argon

GMAW  try a TRI-MIX  (argon, helium, and oxy....best I remember)

Also, I believe the 4043 wire is more for the 3000 series of al. Try a more compatible wire...they make 6061 wire... 

4043 wont work you need 5660 if I remember right ,talk to welding supply co about it they should be able to set you right 

Steve's Welding ck that No# now I have to look what is on the aluim Mig I used to work on boats

6061 is a hard aluim will not bend thats why 4043 cracks it shrinks to much for 6061 plat stronger than the weld

4043 is designed to weld 6000 grade aluminum according to lincoln. I have alreardy got the Gtaw to bend from .125 - .375 plate but the Gmaw is only bending half the time. 6061 will bend just not in a tight radius unless heated before bending. Aluminum Gmaw is not my favorite process especially with a spool gun. I am using 100% argon on both ill see if i have any try mix to try.

You may be getting a faster chill with the MIG so the HAZ winds up being brittle. In addition, I assume you are using AC on TIG, which may be providing some additional cleaning action. Less porosity = more ductility.

Full anneal involves bringing to 800 F for 2-3 hrs followed by cooling at a rate of 50 degrees per hour until 500 F is reached then allow to cool in air. Read up on T-4 and T-6 tempers for 6061.

_{I thought about preheating and cooling in a blanket after to help with stress but im dealing with an AWS CWI and the specs wont let me anneal the base material first. Thank you for the info on annealing. Yes im using AC on the TIG, Miller Dynasty.}