heat treating ER5356 filler alloys to T6 condition

By jwooldridge@fab Date 04-08-2009 18:13

We currently have a job that required welding 6061-t6 using er5356 and then post weld heat treat to the t6 condition.
The parts came back from the heat treatment and then dye penetrant inspected. Numerous cracks were found on all the welds.
The er5356 filler and the heat treatment to t6 condition were both specified on the drawing. Were the filler material and t6 conditions called out in error?

By tom cooper (**)

Date 04-08-2009 19:15

5356 is not heat treatable. If you need to restore the weldment to T6 you should use 4643.
How did you heat treat the item? It is a several step process. Take a look at AMS 2770 or ASTM B918 for the processes, temps and times.

By jwooldridge@fab Date 04-08-2009 19:22

They were heat treated per mil-h-6088e,to the t6 condition which is called out on the drawing.
Thanks for your reply!

By bozaktwo1 (***)

Date 04-09-2009 16:33

Hello there, jwooldridge and welcome to the forums.

Can I ask, before we go on, what code are you welding to, and are you using a properly qualified WPS?

Aluminum is a tricky beast on the best of days, and if you're not prepared for it, you'll find yourself doing a lot of rework. I wonder what the intent is in using the 5356 filler...could it be that these parts are going to be clear anodized, and the customer doesn't want discoloration? In this instance there is little that can be done, as the anodize process will cause your heat-treatable fillers (4043, 4643, etc.) to turn somewhat black. In any case, good luck!