Fe6.5%Si高硅钢凝固过程铁素体相生长行为原位观察

In-situ observation of delta phase growth during Fe-6.5%Si high silicon steel solidification

采用共聚焦激光扫描显微镜(CLSM)原位观察Fe-6.5%Si高硅钢凝固过程中铁素体(δ)相生长行为,揭示了不同冷却速率对高硅钢δ相生长行为和形貌的影响。结果表明,在一定的过冷度下发生L→δ转变,δ相枝晶生长过程中会发生合并现象;随着凝固时间增加,枝晶尖端的粗化速率逐渐降低,L→δ相变开始和结束点延后;通过数据拟合得到二次枝晶臂间距(d)和冷却速度(R)关系:d=53.4R-0.23。

Delta phase growth process was in-situ observed during Fe-6. 5% Si high silicon steel solidification by Confocal Laser Scanning Microscope（ CLSM）, and the growth process and characteristics of δ phase varies on different cooling rate were also investigated. The results show that some cellular δ phase would combine into a bigger one while liquid to δ phase transformation occurred under a certain supercooling. The δ phase grow up rate decreased with the δ phase radius of curvature increased,the start and end point of L→δ phase transformation would be delay with the cooling rate increased. The curved relationship of Secondary Dendrite Arm Spacing（ SDAS） d with cooling rate R was showed as： d = 53. 4R- 0. 23.