But
===

Calculate the metallurgical evolution associated with a thermal history.

The operator functions as a post-treatment of the result of the thermal calculation in the sense that
the latter is an "incoming" data from metallurgical calculation and that there is no coupling between
metallurgy and thermal engineering. Two evolution models are available:

* a model dedicated to austenito-ferritic transformations of steel,

* a model dedicated to the transformations of zirconium alloys.

It is also possible to apply a model to calculate the tempering phases of steel.

The calculation is done at the nodes (field META_ELNO).

The result obtained can then be used as loading data for a calculation.
thermo-mechanical with metallurgy taken into account. It is also possible at the end of a calculation
of metallurgy perform a hardness post-treatment calculation.

Reentering operator, enriches an ``evol_ther`` data structure.