1974 年 23 巻 250 号 p. 564-568
In the previous study, the authors proposed the following prediction equation on the fatigue limit of the smoothed specimen made of tufftrided steel, and clarified the validity of the equation from the experimental data.
σw·t={C1(h/a-h)+(1+C2)}σw·nt
Where, σw·t: fatigue limit of tufftrided specimen
σw·nt: fatigue limit of non-tufftrided specimen
h: hardened depth
a: distance from the surface to the center of specimen
C1: a constant which indicates the hardening due to cyclic stress
C2: a constant which indicates the degree of improvement of fatigue limit due to residual stress
In this paper, the authors describe the results of the fatigue tests on specimens with various a and h, and discuss the limitation of the applicability of this prediction equation from the experimental data.
The results of the discussion are summarized as follows:
(1) The applicable range of the equation is 0.01≤h/(a-h)≤0.6, when the material is 0.15% carbon steel and the rotating bending stress is applied.
(2) In case of h/(a-h)<0.01, the fatigue limit is hardly improved.
(3) In case of h/(a-h)>0.6, the improvement of fatigue limit is saturated.