Influence of combined treatment of the surface layer on the impact resistance of steel

The results of a study of the influence of cold gas-dynamic spraying followed by laser processing of samples made of carbon steel 20 and stainless steel 08X18H10T on their dynamic (spall) strength under impact loading conditions at a strain rate of 10$^5$ $\cdot$ s$^{-1}$ are presented. The influence of impact speed on the microstructure of samples and their spall strength was studied. It was shown that the dynamic (spall) strength of laser-treated samples after their gas-dynamic spraying changed little in relation to samples without treatment. The microstructure of the tested samples was studied. It has been established that a large amount of martensite is formed inside the ferritic grains of carbon steel during impact loading, and intense mechanical twinning develops in the austenitic grains of austenitic steel upon impact, with the largest number of twins observed in samples without laser treatment. In the spall crack zone of the treated stainless steel samples, areas of amorphization and melting were found.