Anomaly in the dynamic strength of austenitic stainless steel 12Cr19Ni10Ti under shock wave loading

Resumo

Measurement results for the shock wave compression profiles of 12Cr19Ni10Ti steel and its dynamic strength in the strain rate range 10⁵–10⁶ s⁻¹ are presented. The protracted viscous character of the spall fracture is revealed. With the previously obtained data taken into account, the measurement results are described by a polynomial relation, which can be used to construct the fracture kinetics. On the lower boundary of the range, the resistance to spall fracture is close to the value of the true strength of the material under standard low-rate strain conditions; on the upper boundary, the spall strength is more than twice greater than this quantity. An increase in the temperature results in a decrease in both the dynamic limit of elasticity and the spall fracture strength of steel. The most interesting result is the anomaly in the dependence of the spall fracture strength on the duration of the shock wave compression pulse, which is related to the formation of deformation martensite near the growing discontinuities.