Yes, like carbon dating it.
Can you carbon date a weld?
If the weld was created at the factory or at a later date.

Example:
Lets say, the factory worker stamped out a piece of metal.
During the stamping process, the stamped out a piece of metal split, tore, ripped or cracked a little.
Rather than trashing the entire piece of metal.
The factory worker repaired the flaw with a weld.

Do you think they would try to repair the piece of metal or trash it?