Corrosion processes in zirconium fluoride-sodium fluoride melts.Study of shortcut cell C/(ZrF₄ – NaF)EUT/Hastelloy

摘要

Time dependencies for the parameters (current, voltage, inner resistance) of shortcut galvanic cell Hastelloy-carbon material have been studied in NaF-ZrF₄ eutectic melt at 600…650°C. Analysis of these data, together with the data on polarization of separate electrodes at open circuit conditions, showed that shortcut current is related to the rate of corrosion of the alloy contacted with carbon, if Zr metal is absent in the system. In presence of Zr, the current corresponds to the rate of zirconium reaction with the melt (related to unit surface of the Hastelloy electrode), and can be used for studies of dissolution kinetics of Zr metal in the melt. It was found that contact of the alloy with carbon material results in the increase of corrosion rate both in pure eutectics and with the additives of LaF₃. Presence of Zr metal suppresses the corrosion process.