6061-t651 as welded strength

[mechengdude]

Can someone supply a yield strength number for 6061-T651 in the as welded condition and a source?

Thanks,

 

[MotorVib]

In the heat affected zone the material drop down to the 6061-O for yield & ultimate Strength. The last time that I need to weld 6061 and hold the proparites of 6061-T6 or T651. I just returned the material back to the -0 condistion and re-heat treated the matial back to the T6.

Chris

"In this house, we obey the laws of thermodynamics." Homer Simpson

 

[TVP]

Typical yield strength for 6061-O: 55 MPa
Source: ASM HANDBOOK Volume 2, page 102, Table 82

 

[RPstress]

You would think it would drop down to condition-O...however, the ASMH (CINDAS/Purdue Aerospace Structural Metals Handbook) shows a R.T. Fty for T6 (not T651, I'm afraid) material 1" thick as-welded of 14 ksi, with a recovery after re-heat treat to 27 ksi (4043 filler wire).

NB: the ASMH quotes AMS 4021, 4022 and 4023 as setting a minimum condition-O Fty as 12 ksi/83 MPa...a bit different from the 55 MPa quoted above. It may depend what spec you've procured to/what industry you work in.

Other graphs in the ASMH indicate an as-welded R.T. Fty of 22 ksi (either 4043 or 5356 filler) with a recovery to 29 ksi (4043) or 37 ksi (5356).

Most references recommend re-heat treating the welded material.

 

[mechengdude]

RPstress - thanks.

Is there any specifcs there about the "preferred" Post weld solution heat treat and age temperatures and times?

 

[RPstress]

I guess can tell you what ASMH says:

"1.052 Solution heat treat. All forms except extrusions 970 F to 990 F. Extrusions 975 to 995 F, water (100 F max) quench...

1.054 T6 Condition. Solution treat + age. Extrusions and forgings 350 F, 8 hours. All other forms 320 F, 18 hours."

Minor caveat: this was written in 1972...

In the related thread in this forum called "Advice on Heat Treating 6061-T651 IAW ASTM B918" TVP has said:

"MIL-H-6088 is now obsolete, but it has information on heat treating Al alloys:

http://assist.daps.dla.mil/quicksearch/basic_profile.cfm?ident_number=5791

"

That has a few more specifics.