shock wave. Variations in pressure and temperature with ball radius and time, P(R, t) and T(R, t), were found
for Lagrangian particles by numerical modeling. The initial pressure at the ball surface was 60 GPa and the load
pulse was 5
s long. The calculated pressure and temperature at the front of the spherically converging wave at a radius of 2 mm were 1000 GPa and 30 000°C, respectively. As it passed through, the load pulse caused the
material to suffer a high-rate deformation at long radii (R > 9 mm) and a solid–melt transformation at the shorter
radii (R
6 mm). As a result of the inertial isentropic after-compression, the melt was forced to solidify. In the unloading wave and at high residual temperatures, the metal melted at R
9 mm. At R 3 mm, the material changed to a vapor state. The loading by strong stress waves gave rise to numerous defects in the material.
Atthe center of the sphere, a cavity was produced with an effective volume of 221.5 cm3 and a radius of
37.5mm. In the material of the compressed and saved sphere, optical and scanning electron microscopy
revealed macrostructural features traceable to the melting and evaporation of the steel in spherical stress waves.