in the creep test a sample at more constantly (more increased) temperature of a constant load is exposed and the time-dependent stretch (creep deformation) as well as the time up to the break measured. The increased temperature is necessary, since in the material procedures running off are connected with diffusion and this is thermally activated. Depending upon dominating mechanism one differentiates between transfer and diffusion creeping.
On the basis of the results creep curves and creep charts are then provided.
Extension boundary lines (and/or. the time break boundary line) give against it for given stretch (and/or. for the break) the permissible tension as function of the time on, the material up to reaching the stretch concerned (and/or. up to the break) to hold is.
A related attempt is the relaxation attempt, with which when constant stretch the temporal reduction of the tension is seized.