Erosion-corrosion of RAFM JLF-1 steel in Lithium flow induced by impeller
The purpose of the present study is to investigate erosion-corrosion characteristics of reduced activation ferritic martensitic steel, JLF-1 (Fe-9Cr-2W) in flowing Li. The erosion-corrosion characteristics were investigated by means of corrosion tests with rectangular plate type specimen of JLF-1 in Li stirring pot, where the Li flow was induced by impeller in the pot. The test temperature was 500 C and 600 C, and there was no temperature difference in the Li stirring pot. The erosion-corrosion characteristics were evaluated by the weight loss measurement of the specimens and metallurgical analysis for the corroded surface. The results were compared with those obtained from the tests at static condition to feature the effect of Li flow on the corrosion. The weight loss of the specimens tested in Li flow was larger than that tested in the static tests. The corroded surface showed the local corrosion along lath boundary and grain boundary of JLF-1 as the same as that after the test at static condition. There were defects which were not observed in the specimen tested at the static condition. The defects were the trace of the erosion-corrosion. The corrosion attack to the boundaries made weak bonding between the subgrains, and the subgrains were peeled from the surface by the Li flow.
Mass transfer of RAFM steel in Li by simple immersion, impeller induced flow and thermal convection
Abstract The compatibility of reduced activation ferritic steel, JLF-1, was investigated by the corrosion tests in static lithium (Li), impeller induced Li flow and thermal convection Li. A simple model for corrosion of JLF-1 in Li was based on the equation of mass transfer and mass balance in the corrosion test. Solubility of Cr in Li was evaluated as 37.6 wppm at 500 °C and 77.2 wppm at 600 °C based on the data obtained in corrosion tests in static Li. The mass transfer coefficient of the dissolved Cr from the steel in static Li was experimentally determined to be 4.08 × 10−8 m/s at 500 °C and 1.81 × 10−7 m/s at 600 °C. The mass transfer coefficient for impeller induced flow calculated from Sherwood number and literature value of the diffusion coefficient was 1.34 × 10−4 m/s at 500 °C and 1.40 × 10−4 m/s at 600 °C. Theoretical values for the corrosion loss were compared with values obtained from the experimental data. The mass transfer coefficient determined for the thermal convection loop was 1.73 × 10−5 m/s.
SR topography of plastically deformed Fe-Si bicrystals - observation in situ and post mortem
SR reflection topography was applied to study the interaction of slip dislocations with the grain boundaries in Fe-4at%Si bicrystals deformed by compression. Three experimental settings with either a white or monochromatic beam were used and the corresponding orientation contrast analysed. Dislocation transmission through the grain boundary was observed in bicrystals with favourable geometry of the slip systems.