Fatigue behaviour and mean effects in grey cast iron

Strain cycle fatigue concepts are well integrated into fatigue life prediction methodologt for wrought components. Concepts developed for wrought materials cannot be directly extended to cast materials because of differences in the fatigue mechanisms, but the framework of a life prediction method for cast iron components will be similar. Observations and results of constant-amplitude completely reversed fatigue tests performed in strain and load control are reported for a pearlitic grey cast iron. Mean amplitude tests in both control modes have been conducted to evaluate the effects of mean stresses and strains. A parameter of the form ( σ max Δ∈) gives good correlation of all the fatigue tests performed and provides a simple relationship to fatigue life.