The effect of the diffusion of interstitial atoms on strength loss of steels

The relation σB=σ∞+const. t−1/4B has been deduced for the time dependence of the strength decrease under a sustained load. Experimental data of the strength decrease of steel due to static load and cyclic loading are represented in (t−1/4, σ) diagrams. They have been analysed to determine the degree to which the run of the data points is linear. A linear functional dependence of the data points gives the possibility of extrapolation, either to a minimum static stress sustained by the material for an infinitely long period of time or to a fatigue limit. The minimum static strength values and the fatigue limits have been determined for the analysed experimental data of several authors.