Failure-delay effect in destruction of steel samples under spalling conditions

Dynamic spalling tests have been run on two batches of 30KhN4M steel samples. Experimental data have been processed with the classical technique based on solution of the elastic wave equation. Three samples have been revealed that demonstrated the failure-delay effect under testing. The incubation-time criterion has been used to show the conditions of emergence of failure delay with the example of triangular loading pulses. A rate strength curve has been constructed for the other samples. It has been shown that the limiting strengths under dynamic loads considerably differ for samples from different batches despite the same chemical composition and static strength.