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[Библиогр.: 10 назв.]

A comparative study of shock-wave hardening and spall fracture characteristics of austenitic 304L and Hadfield steel targets up to 10 mm thick at strain rate of ~ 10 6 s -1 are presented. An accelerator “SINUS-7” which formed the high-current nanosecond relativistic electron beam (1.35 MeV, 20 kA, 45 ns, 3.4-10 10 W/cm 2) was used as a shock-wave generator. It was found that, regardless of the steel type and target thickness, the microhardness depth profiles have a near-surface maximum, located at the depths of 0.5-1 mm from the bottom of the ablation hole, which correlates with the simulated thickness of the heat affected zone of the e-beam. In the absence of spallation, a second microhardness maximum associated with the reflection of a shock wave from the rear surface is formed near the back surface, and this effect is more pronounced for Hadfield steel. It was shown that the rear spallation is carried out in the mixed ductile-brittle mode by intergranular (Hadfield steel) and mixed trans-and intergranular (SS 304L) fracture. The thickness of the spall layer increases almost linearly with target thickness up to ~ 0.7 mm, which agrees satisfactory with simulation. Correlations between microstructure of steels and spall fracture modes were found.