Fatigue failure is the most common failure mode of structural materials.
In this study, the high-cycle fatigue properties at different
temperatures, fracture surface morphologies and corresponding damage
mechanisms of a widely used vermicular graphite cast iron RuT450 were
investigated. It is found that the fatigue strength of RuT450 decreases
with the increase of temperature, and the decreasing rate is affected by
the change of morphology and content of graphite. In general, the cracks
initiated from the graphite phase boundary and propagated through the
pearlite lamellae. In addition, according to the change of matrix
micro-structure and the slight change of graphite morphology at
different temperatures, and combined with the change of crack
propagation threshold value under different temperature conditions, a
fatigue strength prediction method for vermicular graphite cast iron at
different temperatures was proposed in this work, which has high
prediction accuracy.