CAJ | 학술논문

研究了不同凝固组织下管线钢的中心偏析情况。低倍组织腐蚀结果表明，连铸板坯的中心偏析由相对独立的、大小不一的半宏观偏析点组成，且不同凝固组织的半宏观偏析特征有所差别。化学成分分析表明，中心等轴晶时板坯中心为负偏析，且贯穿于整个等轴晶区中，而中心为柱状晶时则表现为正偏析。通过对比化学成分和半宏观偏析面积比发现，板坯的半宏观偏析面积比随 C 和 Mn 最大偏析度的增加而增加，由于化学成分分析只能反应局部位置的偏析情况，因此半宏观偏析面积比的方法对生产实践更具有指导意义。对不同过热度下不同凝固组织的半宏观偏析面积比的统计结果显示，在合理使用轻压下技术的前提下，中心为柱状晶更有利于减轻半宏观偏析面积比，进而改善管线钢连铸板坯的中心偏析。
연구료불동응고조직하관선강적중심편석정황。저배조직부식결과표명，련주판배적중심편석유상대독립적、대소불일적반굉관편석점조성，차불동응고조직적반굉관편석특정유소차별。화학성분분석표명，중심등축정시판배중심위부편석，차관천우정개등축정구중，이중심위주상정시칙표현위정편석。통과대비화학성분화반굉관편석면적비발현，판배적반굉관편석면적비수 C 화 Mn 최대편석도적증가이증가，유우화학성분분석지능반응국부위치적편석정황，인차반굉관편석면적비적방법대생산실천경구유지도의의。대불동과열도하불동응고조직적반굉관편석면적비적통계결과현시，재합리사용경압하기술적전제하，중심위주상정경유리우감경반굉관편석면적비，진이개선관선강련주판배적중심편석。
Center segregation with different solidification structures was investigated in pipeline steel. Macrostructure photographs show that center segregation in continuous casting slabs is composed of many semi-macro segregates, which are relatively independent and separated spot-like segregates with different sizes. The features of semi-macro segregation are different for different solidification structures. Chemical analysis shows that negative segregation is formed across the equiaxed zone in the center of the slab, while positive segregation is observed in the center of the slab surrounded by columnar crystals. It is revealed that the semi-macro segregation area in the center of the slab increases with the increase of the maximum segregation ratios of C and Mn. However, compared with the method of segregation area measurement, only local segregation could be obtained by chemical analysis, and it is obvious that the method of segregation area measurement is more helpful to industrial practice. Furthermore, the segregation area with different solidification struc-tures under different superheats was calculated. The results indicate that as the soft reduction technology is applied reasonably, colum-nar crystals in the center of the slab are more advantageous to the reduction of segregation area, and finally would be better for the im-provement of center segregation.