In the process of long-term operation of steam pipes of heat-resistant steels under creep conditions, physical and chemical processes take place in their metal, which ensure the transformation of the initial structure of steam pipelines into a ferritic–carbide mixture. Such processes are characterized by the presence of recovery and recrystallization. Their distinction from the classical recovery and recrystallization is that the recovery and recrystallization of steam pipelines in metal are not as an effect of peeling off during annealing by separating the energy stored during deformation, but as a transition of the alloyed system to a state characterized by lower-energy levels. Phase slander is removed. The recovery of welded joints in the metal occurs more intensively than in the base metal of the steam pipelines themselves that is ensured by the presence of significant structural, chemical and mechanical heterogeneities.