Influence of Surface Ultrafine Grain Structure on Cavitation Erosion Damage Resistance

Abstract

Ultrafine-grained structures (UFGS) are formed after severe plastic deformation (SPD) using the method of vibration-centrifugal hardening (VCH). This method provides greater depth due to the significant mass of the hardening tool. Under optimal conditions, vibration-centrifugal hardening during cold plastic deformation forms an ultrafine-grained ferritic structure with a grain size of 190 nm and high dislocation density and reaches microhardness of 8.9 GPa and a hardening depth of 7 mm on the 40Kh steel surface. The dependence of the corrosion and electrochemical characteristics as well as cavitation erosion damage resistance on the processing modes is shown. However, vibration-centrifugal hardening increases the cavitation erosion damage resistance by two times after stabilizing the destruction rate and by ten times at the incubation time.