Isothermal low-cycle fatigue and fatigue-creep of a 42CrMo4 steel

Abstract A series of strain-controlled experiments was performed on quenched and tempered martensitic steel 42CrMo4, with and without a tensile peak strain-dwell. The experiments were performed for three different strain rates and for two different strain dwells in the temperature range between 300 and 600 °C. Scanning electron microscopy and optical microscopy were then used to study the microstructure evolution and the damage mechanisms. The experimental results show that tensile peak strain-dwell may lead to interaction between creep and fatigue. Finally, the effect of a decreasing strain rate and increasing duration of the strain-dwell on the observed fatigue lifetime is quantified.