Experimental Study on Dynamic Mechanical Properties of Ultrahigh Strength 30CrMnSiNi2A Steel

As an outstanding performance aviation material, the understanding of dynamic behavior of ultrahigh strength steel 30CrMnSiNi2A at high strain rates is of importance in a range of applications. The curves of stress and strain in different strain rates (500~5000s^-1) of 30CrMnSiNi2A steel are obtained with split Hopkinson pressure bar(SHPB) experiments, and the micro-deformation characters were observed by metallography. The results indicate that 30CrMnSiNi2A steel is sensible of strain rate, and dynamic compression leads to shear failure with the angle 45°. The yield stress increases from 1655MPa to 1908MPa with increasing strain-rate (500~5000s^-1). Through metallographic analyses, the failure is found to be dimple intercrystalline fracture under high strain-rate loading. Meanwhile, the material parameters of Johnson-Cook model are determined through the SHPB experiments and quasi-static results.