Corrosion fatigue is dependent on the interactions among loading, environmental, and metallurgical factors. For a given material, the fatigue strength generally decreases in the presence of an aggressive environment. The effect varies widely, depending primarily on the particular metal-environment combination. The environment may affect the probability of fatigue crack initiation, the fatigue crack growth rate, or both. The rate of brittle cracking above that produced in vacuum generally decreases with increasing frequency.
Frequencies exist above which corrosion fatigue is eliminated.
Stress ratio - Rates of corrosion fatigue crack propagation are typically increased by increase in the stress ratio. However, stress ratio has only a slight influence on fatigue crack growth rates in benign environments. Strongly influences corrosion fatigue in aqueous environments. Controlled changes in the potential can result in either the complete elimination or the dramatic increase in brittle fracture cracking. Environment - Increasing the chemical activity of the environment decreases the resistance of the material to corrosion fatigue.