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.
Corrosion-Wear Resistance and Interfacial Morphologies of Novel Fe–Cr–B Cast Steels in Molten Aluminum
In order to improve the corrosion–wear resistance properties of steels in molten aluminum, novel Fe–Cr–B cast steels with different boron concentrations were prepared. The steels were investigated at 750 °C for 0.5 h using a ring-block corrosion–wear test, and the interfacial morphologies were examined. Results showed that the corrosion–wear resistance of the Fe–Cr–B cast steel was three times that of H13, and benefited greatly from the effects of the primary Cr-rich Fe2B, which bore the main load during the corrosion–wear test. The corrosion–wear behavior of the coarse primary Cr-rich Fe2B in molten aluminum was clearly different from that in static molten aluminum.
Effect of stress conditions on collapse deformation behavior of a rockfill material
A set of saturated and dry-saturated large-scale triaxial tests were conducted in order to explore the effects of stress conditions on the saturation-induced collapse deformation behavior of a rockfill material. Specimens were tested in different confining pressures and for dry-saturated tests the specimens were submerged in various shear stress levels. The results indicate that in all of the dry-saturated tests a sudden reduction in the volume of the specimens was observed during the submerging process. The ratio of the minimum axial strength of a submerged specimen (at the end of the saturation process) to the shear strength of the specimen before saturation is defined as the coefficient of stress recovery, Csr. Results of the dry-saturated tests showed that this ratio increases as the confining pressure increases and decreases by increasing the shear stress level. According to the results of dry-saturated tests the values of internal friction angle reduction caused by saturation (Δϕc), the ratio of the elasticity modulus of the material after saturation to its elasticity modulus in dry condition, i.e., Ewet/Edry, and also the saturation induced sudden volumetric strain (εvc) decrease as the confining pressure increases. However the shear stress level does not have any meaningful effect on the variation of Dfc, Ewet/Edry and (εvc).