capacitance of capacitor 200 μF) treated liquid 45 steel (0. 43% C) for 60 s before tapping from 10 kg medium frequency furnace ( before solidification) or with same pulse current treated liquid for 3. 5 min during solidified process in casting mold
it was found that both pulse current treated methods all were able to improve solidified structure of steel
i. e. increased equiaxial crystal
decreased columnar crystal. reduced Widmannstattern structure and decreased interlamellar spacing of pearlite
besides to improve chemical composition segregation
the segregation index of carbon
sulphur and phosphorus respectively decreased to 1. 125 ~ 1. 194
1. 067 ~ 1. 300 and 1. 227 ~ 1. 092 with pulse current treatment from 1. 257
1. 502 and 1. 384 without pulse current treatment.