円形空孔浸出法による鋼の固液共存層内の有効透過係数と透過率の評価

抄録

The fluidity of the liquid in the solid-liquid coexisting zone of carbon steel was measured by the seepage of interdendritic liquid into a cylindrical hole formed in that zone. The effective permeability K has been determined in relation to the fraction of solid f_S and cooling rate R, and the speciffc permeability k which depends on the dendrite morphology has been deduced from the effective permeability to give, log K=log 0.10 R^0.81+19.6 R^0.33 log (1-f_S)……(2)
log k=log 1.5×10^-6 R+20.3 R^0.35 log (1-f_S)……(11)
The fraction of solid at which dendrites begin to form networks is 0.290.30 depending on the cooling rate. The effective permeability is 6.3×10^-4 cm/s and the specific permeability is 6.0×10^-9cm². On the other hand, the fraction of solid above which the liquid cannot flow through the dendrites decreases from 0.73 to 0.60 as the cooling rate increases from 0.033 to 0.15°C/s. The values of effective and specific permeability become constant, 1.6×10^-6 cm/s and 2.1×10^-11 cm², respectively, although the fraction of solid is changed by the cooling rate. It has been shown that the effective permeability is mainly controlled by the specific permeability. The fluidity of silicen-free steel which contains 1% molybdenum is smaller than that of carbon steel.