High Rate Pulse-Galvanostatic Anodic Dissolution of Nickel-Chromium Steels in Electrolytes for Their Electrochemical Machining. Impact of Surface Temperature

Pulse-galvanostatic dissolution of steels Cr18Ni10 and Cr35NiWTi at current densities up to 100A/sm² under conditions of their electrochemical machining in chloride, nitrate, and mixed chloride-nitrate electrolytes was investigated. In was shown that at a pulse duration of 20µs – 2 ms and a duty cycle of ˂ 50% in all solutions (except the dissolution of Cr35NiWTi in chlorides) the limiting Faraday dissolution rate (~0,18mg/C) is achieved. This corresponds to the values of the current efficiencies for dissolution of Cr18Ni10 - 50% and of Cr35NiWTi - 68%. An increase of the current efficiency at transition to direct current takes place. The determining role in this process is that of a rise in the surface temperature.