Prof. Kan Qianhua’s team have recently published two papers in International Journal of Fatigue after they have completed strain and stress fatigue experiments on carbide-free bainite rail steels under different heat-treatment conditions and studied the effect of microstructure and retained austenite (RA) on the ratchetting-fatigue interaction from the macro and micro levels respectively.

Fig. 1. The ratchetting-fatigue interaction of carbide-free bainite rail steels

The model precisely predicts the strain amplitude-dependent cyclic softening feature, tension-compression asymmetry and transient Bauschinger effect.

Fig. 2. The cyclic plasticity constitutive model of carbide-free bainite rail steels

The study is supported by the National Key R & D Program, National Natural Science Foundation of China and Applied Basic Research Project of Sichuan Province.