1. Steel creep

1.1 Macrographic aspects of creep

The macroscopic evolution of creep deformation takes place under specific conditions (constant load and temperature) and in such a way that the rate of deformation (the so-called creep rate) varies continuously over time; it is described by the "creep curve". This curve has the appearance shown in figure 1 , which is conventionally broken down into several phases that follow one another in time:

• loading at the instant when, after temperature stabilization, the test load is applied. This generates instantaneous OA elongation, which may be totally elastic or partially elastic and partially plastic, depending on temperature and...