Aiming to research the thermal fatigue behavior of die casting steel,laser remelting on surface of Dievar steel with quenching and tempering state was carried out by pulsed Nd:YAG laser.And the thermal fatigue properties of the samples have been studied with self-restricting test method.The results show that the propagation of thermal fatigue crack in Dievar steel treated by laser remelting exhibits lower speed than that of conventional heat treatments.The fatigue crack near the laser remelting zone has bee...