"Shelf-Life" of Alum 6061 Tubing
"Shelf-Life" of Alum 6061 Tubing
(OP)
Is there such a thing as a shelf-life for seamless 6061-T4 tubing? What about 6061-T6?
The diameter of the tubes in question is 2" and less and we store them indoors.
By shelf-life I mean a change in yield strength or hardness over time (6 months to years).
I have been unsuccessful in obtaining information from our tubing supplier.
Thanks in advance for any thoughts.
The diameter of the tubes in question is 2" and less and we store them indoors.
By shelf-life I mean a change in yield strength or hardness over time (6 months to years).
I have been unsuccessful in obtaining information from our tubing supplier.
Thanks in advance for any thoughts.





RE: "Shelf-Life" of Alum 6061 Tubing
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: "Shelf-Life" of Alum 6061 Tubing
RE: "Shelf-Life" of Alum 6061 Tubing
6061-T4 is solution heat-treated
6061-T6 is T4 + artificial aging
More?
Alloys in the 2xxx, 6xxx and 7xxx groups can be strengthened by a heat treatment process. The aluminum is heat treated by carrying out a solution treatment process, in which the metal is heated to an elevated temperature followed by rapid cooling, then a precipitation hardening process (or "aging" process). The tempers are designated by -T followed by a digit. Some common -T tempers are as follows:
-T3
Solution heat-treated, cold worked and naturally aged: Applies to products that are cold-worked to improve strength after solution heat-treatment, or which the effect of flattening or straightening is recognized in mechanical property limits
-T4
Solution heat-treated and naturally aged: Applies to products that are allowed to age harden at room temperature following a solution treatment.
-T6
Solution heat-treated and artificially aged: Applies to products that are reheated to a low temperature following a solution treatment. This allows the metal to achieve its highest heat-treated strength level.
RE: "Shelf-Life" of Alum 6061 Tubing
RE: "Shelf-Life" of Alum 6061 Tubing
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: "Shelf-Life" of Alum 6061 Tubing
CoryPad:
Can you please list your ASM reference?
I'll use it to document the information.
Thanks again,
Ron
RE: "Shelf-Life" of Alum 6061 Tubing
http://ww
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: "Shelf-Life" of Alum 6061 Tubing
Actually the low carbon, no alloy steels will age at room temperature. This is a result of solution amounts of nitrogen and carbon in the steel. (IE really soft 1004/1006 only will have its good forming properties for ~6mths at room temp). The newer IF (interstitial free) steels do not do this and are referred to as stabilized grades.
If the Deep Drawing Quality steel sits too long in the warehouse then it will develop stretcher strains (luder lines) in the steel when formed.
One way to prevent this is to temper roll or strech level the material. This is done by appling ~.5% strain to the steel.
RE: "Shelf-Life" of Alum 6061 Tubing
What material property changes would occur as 1004/1006 ages? Magnitude and how quickly?
RE: "Shelf-Life" of Alum 6061 Tubing
For highly drawable and formable grades the Mill wont generally consider the mechanical certs good past 6months.
For parts right near the forming limit this aging can mean the difference btw. a good part and bad part.
(note the above applies to common drawable grades of steel. I have no knowledge of aging in other grades.)