What happens if you reheat already tempered metal?

All kinds of metals are baked inside, under, next to, etc, polymer clay (any brand/line including Premo) and there will be no problem since the temps used for curing polymer clay are so low (usually 275 F).

(Also, there is *seldom* any problem with cracking when polymer clay is used inside, under, etc. metal--only in a very few rare circumstances.)

There's more on using metal with polymer clay on these pages of my polymer clay site, if you're interested:

http://glassattic.com/polymer/armatures-perm.htm

http://glassattic.com/polymer/covering.htm

For baking/curing polymer clay, you might also be interested in this page:

http://glassattic.com/polymer/baking.htm

.

Tempering is a multistep process and quenching does hardening and slow heating does removing brittling. Baking polymer clay, which is done at more like 275F is still low enough to not affect the temper.

Depending on how thick and how wrapped, the clay may crack on shrinking around the metal on baking.

Heating an alloy causes various crystals to form. It takes certain temperatures, and you have to maintain the temperature long enough for the crystals to do their thing. Then you cool the metal quickly so it can't change to a different crystal. So your question depends on what alloy, what temperature, and how long.

200 degrees would do nothing.