Study on the relevance between cavitation and cavitation erosion of pure water hydraulic control check valve under the impact of high pressure and large flow

The relationship between impact cavitation characteristics and cavitation damage of a pure water hydraulic control check valve under high pressure and high flow was investigated to prevent cavitation damage. The surface shape, phase, chemical state, and polarization curve of the hydraulic control check valve after pure water impact at high pressure and high flow were analyzed. The results indicate that the greater the impact pressure, the more pronounced the pressure drop at the throttle and the greater and more intense the cavitation range at the flow passage's rear end. Less impact pressure results in a quicker unloading process, and impact pressure has a significant effect on unloading time. With the improvement of impact characteristics, both the cavitation index and cavitation damage intensify. Cavitation collapse can rapidly transfer high temperatures to the surface of stainless steel, resulting in a martensitic structure through the rapid cooling of a pure water medium. After cavitation collapse, the passivation film of the stainless steel surface appears with early cracks and pores, which are more fragile than the surrounding area, resulting in a higher current density in the contained area, resulting in more H+ in ionization, thus an acidic corrosive solution, and accelerating the destruction of the passivation film.