连铸板坯宏观偏析特性

Continuous Casting Slab's Macrosegregation Characteristics

应用金属原位分析仪,对铸坯的成分偏析状况进行了分析。铸坯试样为120 mm中等厚度连铸坯。分析结果发现:铸坯中心偏析成岛状出现在中心线附近,且彼此孤立,中心成分起伏波动大,最大偏析一般在中心位置;正偏析元素(k<1)在整个中心等轴枝晶区域内含量均比较高(即偏析值较大);柱状晶组织向等轴状晶的过渡区为严重偏析的高发区域。

The composition segregation of continuous casting slab （ 120 mm in thickness） has been analyzed with an original position analyzer for metal. The result shows that the central segregation can be found around the central line like some isolated isles. The composition at the center fluctuates greatly and the maximum segregation usually appears in the center. Furthermore, the content of elements with positive segregation （ k 〈 1 ） is higher in the whole area of equiaxed gains. That is the segregation value is greater in this area. The transition area where columnar structure turns to equiaxed grains is a zone where serious segregation occurs.