1. The main lines of thermo-metallo-mechanical calculation

In Code_Aster, thermal, metallurgical and mechanical calculations are decoupled. The successive steps of a complete calculation are as follows:

	A thermal calculation is carried out that makes it possible to obtain the temperature field at each node.
	Metallurgical calculation is carried out by post-processing the thermal calculation, which makes it possible to obtain the proportion of the various metallurgical phases at each node and possibly the associated hardness. In Code_Aster, you can treat two different types of material, which undergo metallurgical transformations: steels or ZIRCALOY. We are only interested in steel-type materials here. For a steel, five different metallurgical phases can be taken into account: ferrite, pearlite, bainite, martensite, called phase \(\alpha\), and austenite, called phase \(\gamma\).
	Based on the temperature field and the metallurgical phases, the mechanical calculation is carried out by choosing a behavior model that takes into account the various possible effects of metallurgical transformations. We thus obtain the fields of stresses, deformations and internal variables at each Gauss point.