Abstract
UDC 541.138.2+621.0.147.7
DOI https://doi.org/10.52577/eom.2022.58.2.01
It is shown that at high-speed pulsed galvanostatic anodic dissolution of chromium-nickel steels Kh3N35VT (CSN17335), Kh18N10 (AIS1 304) in the regions of pulse durations of 20–2000 ms and current densities of 1–100 A/cm2 in electrolytes for their electrochemical dimensional machining (ECDM) (chloride, nitrate, and mixed chloride-nitrate with an electrical conductivity of 0.15 S/cm), a significant part of the charge (up to 50%) is spent on the formation of a passivating oxide film having a semiconductor character. As a result, the film, not the alloy, is subject to electrochemical treatment. As a result, the current output of the ECDM process of these materials under pulsed conditions is ~ 50–70%, depending on the composition of the alloy. The speed of the process increases with the transition to a constant processing current because of the destruction of the film due to its thermokinetic instability (“thermal explosion”) caused by an increase in the surface temperature.
Keywords: chromium-nickel steels, electrochemical dimensional machining, oxide films, passivation, electrolytes for electrochemical dimensional machining, pulse dimensional machining, destruction of oxide films.