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Molten Salt Corrosion Behavior of the Rolled High purity Chromium Plate

1990; Japan Institute of Metals and Materials; Volume: 54; Issue: 7 Linguagem: Inglês

10.2320/jinstmet1952.54.7_794

1880-6880

Masayuki Yoshiba, Hiroshi Wada, Takashi Sakaki, Masatoshi Kato,

Nuclear Materials and Properties

In order to evaluate the utility of a high purity Cr plate developed by an improved processing technique with powder metallurgy for a high temperature corrosion resistant structural material, the molten salt corrosion tests were performed by the laboratorial salt coating method at 1073-1173 K using the V2O5-Na2SO4-NaCl systems of salt mixtures, and the corrosion behavior was investigated from various points of view. The isocorrosion contour; the corrosion map, was established for high purity Cr in the tertiary salt system, suggesting the strong dependence on a NaCl concentration of corrosion resistance. The corrosion kinetics of the representatitve molten salt systems, corresponding to vanadium pentoxide attack and hot corrosive environments were also investigated, to reveal its conformity to a nearly parabolic rate law in both environments. Different aspects of the corrosion behavior were discussed in connection with scale analyses, and it was suggested that Cr2O3 could be always formed at the metal/scale interface to provide a protective barrier. Furthermore, the effect of the pre-oxidation treatment on the corrosion resistance improvement for the high purity Cr was investigated to confirm the improvement in corrosion performance under a variety of molten salt environments.