Hi Jeff!
I agree! One would have to include how much CCV voltage is being used to keep the current flowing as well as how much resistance would occur which is also dependent on both the material and whether or not there is any insulation to prevent some electron loss also...
So it is really the amount of resistance occurring within the chain that would be the culprit for enough residual temperature increases to occur for a certain amount of time to possibly cause changes in the crystal matrix, at random locations, yet more likely closer to the opposite end of where the current is starting to flow across the chain from unless of course, if the polarity is reversed which would cause the opposite affect, and thus affect it's metallurgical properties as well as it's mechanical properties also regardless of where the current originates from.
Which means that there would have to be a whole lot of current passing through, and being forced through the chain by such a little amount of Closed Circuit Voltage (CCV) in order to create enough resistance that even if the chain were not insulated, the electrons would still congregate at random locations without dissipating through the conductor itself (chain made of steel which has a much higher resistance than copper, or aluminum for that matter, and the length of the chain also has to be taken into consideration too! ) for such an amount of time for this phenomena to occur - CAPECHE???
So, a low enough Open Circuit Voltage setting (OCV), and the increased Resistance of the metal especially at locations away from points of contact between the links of the steel chain, in combination with the amount of current being forced through the length of the steel chain for a certain amount of time would all have to be present in order for this phenomena to occur... Clear as MUD - RIGHT??? :) :) :)
Respectfully,
Henry