Metallurgical analysis and computer simulation of a solid steel sphere under shock loading.

An explosive-based spherical shock-recovery system was used to load an annealed solid steel sphere. The hydrocode CTH was utilized to model the explosive-metal interaction. Based on the simulation results, pressures reached as high as 100 GPa (1 Mbar) at the surface and converged to 1.25 TPa (12.5 Mbar) at the center of the sphere. As the computer simulation predicted, post-shock examination of the recovered sphere revealed a large void at its center created as a result of strong tensile waves emanating from the surface. Micro-hardness measurements showed a hardness at the surface of the sphere approximately twice the hardness at its center. X-ray analysis of the pre and post shocked samples revealed no permanent phase transformation. [ABSTRACT FROM AUTHOR]