低サイクル腐食疲労における応力波形の影響

抄録

Studies have been made of the influence of stress rate in trapezoidal strain waves on low cycle corrosion fatigue strength. The electrode potential of the specimens has been observed against the saturated calomel electrode during the cycles. The following facts have been made clear;
(1) The corrosion fatigue strength is affected by the stress wave forms. The durability of the material gets cut short by the longer strain time in which the strain ranges from zero to maximum, owing to the fact that the corrosion potential of the specimens is retarded and does not follow up to the equilibrium state of stress.
(2) The effect similar to the effect made on the strain time is found to be made on the stress rate. In the range of lower stress, however, the stress rate has less effect because the maximum duration of time of stress becomes more effective than the strain time.
(3) When lower stresses are applied, the strain time has its effect on the period of pitting formation and of crack propagation, while the effect on the latter is much smaller than on the former under higher stress range.