Low Cycle Fatigue Behavior of HT250 Gray Cast Iron for Engine Cylinder Blocks

摘要: The strain-controlled low cycle fatigue properties were evaluated on specimens of HT250 gray cast iron (GCI) at room temperature. material exhibited cyclic stabilization a strain amplitude 0.1% and softening characteristic higher amplitudes (0.15-0.30%). At representative total (0.30%), the hysteresis loops GCI asymmetric with large amount plastic deformation in compressive phases. Furthermore, loop became larger both width height increasing (from 0.10 to 0.30%), tended exhibit clockwise rotation. crack propagation mechanisms different various amplitudes, where high stress concentration due dislocation pile-up favored initiation examined HT250. Finally, roughness-induced closure was key determine growth rate as well life.