Abstract
Unidirectional solidification of Fe-25% Cr-3.5% C eutectic high chromium white cast irons was conducted under a solidification rate range from 1.3×10-3 mm/s to 1.3×10-1 mm/s to clarify the deformation behavior of the irons at elevated temperatures. The alloy specimens were processed in the parallel and vertical directions to the solidification direction, and a compression test was done under a strain rate range from 2.5×10-4 to 1.7×10-2 at various temperatu res up to 1073 K. The relation between the microstructure and high temperature strength was studied. The strength depended on the morphology of eutectic cells and the orientation of primary carbides. The maximum compressive strength of the parallel direction to the solidification direction was larger than that of the vertical direction within the whole temperature ranges. The strain rate sensitivity exponent showed larger value in the vertical direction than in the parallel direction. These results suggest that the strength of the parallel direction is mainly supported by the elongated primary carbide phases, while the strength of vertical direction is supported by the iron matrix and strongly depend on the deformation behavior of the iron matrix. The rule of mixtures was used for analysis of the experimental results described above.
