Abstract: With pulse current ( 2 600 V, 0. 862 Hz, 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.

摘要： 45钢(0.43%C)在10kg中频感应炉出钢前(凝固前)经2600V、0.862Hz、电容器电容量200μF脉冲电流处理60s和钢水在铸模凝固过程用相同参数的脉冲电流处理3.5min后发现,两种脉冲电流处理方法均能改善钢的凝固组织:增加等轴晶和减少柱状晶数量,并减少魏氏组织,使珠光体片层间距减小;同时改善了钢的成分偏析,碳、硫、磷的偏析指数分别由未经脉冲电流处理的1.257、1.502和1.384降低至脉冲电流处理的1.125～1.194、1.067～1.300、1.227～1.092。

关键词: 脉冲电流处理, 45钢, 凝固组织