Experimental Investigation on Spall Fracture of 30CrMnSiNi2A Steel

Spall fracture is a damage that occurs in a body when two rarefaction waves interact and produce enough dynamic tension breakage,and then the spall zone is founded in the interior of the target.Behavior of materials in the spall phenomenon is strongly affected by the stress level,time of loading and so on.The spall properties of 30CrMnSiNi2A steel loaded by a gas gun were investigated using the planar impact experiment and the two-wave structural profiles of free surface velocities of specimens were recorded by velocity interferometer system for any reflector (VISAR) techniques.The Hugoniot elastic limit (HEL),spall strength,spall thickness and strain rate were obtained in the plate impact experiments of 30CrMnSiNi2A steel specimens with different thickness.The result indicates that the values of HEL and spall strength increase with the increasing strain rate.The dynamic spall fracture and corresponding microscopic mechanism of 30CrMnSiNi2A at different strain rates were evaluated through the fracture analysis and fractography using a scanning electron microscope (SEM).