Abstract: In order to analyze the effect of pre-compression on the fatigue performance of steel plate, an experimental study on the fatigue performance and fracture morphology of automotive DP590 steel plates in initial hot rolled state and with 10% pre-compression are conducted respectively. The results show that by applying 10% pre-compression, the fatigue limit of the material increases by 10.6% from 282 to 312 MPa. Meanwhile, the fracture surfaces of specimens in two states are also analyzed, and original region, extended region and instantaneous broken region can be clearly seen. The first fatigue crack appears at the corner of specimen, and there exist a large number of dimples and micro-cracks with different lengths in instantaneous broken region.

Key words: DP590, fatigue performance, pre-compression deformation, fracture morphology