Effect of Balanced Biaxial Stretching on the Low Cycle Fatigue Behavior of SAE 1008 Hot Rolled Low Carbon Steel

The effect of prestraining on the tensile properties and uniaxial low cycle fatigue behavior of SAE 1008 hot rolled low carbon steel strip has been investigated using a prestraining technique which simulates a press forming operation. Preliminary data for the case of a 40% balanced biaxial prestrain show a considerable increase in fatigue resistance in the long life regime. The reduced ductility as a result of prestraining, however, causes degradation of the short life fatigue resistance. Therefore, for component operation in the long life regime where the strains are mainly elastic, SAE 1008 may have considerably greater fatigue resistance than a designer would anticipate based on the yield and ultimate strength levels or fatigue data of the as-received material.