부산대학교 도서관

In order to reveal the formation mechanism of microstructural delamination in flange steel during punching, the microstructuralcharacteristics of flange steels with 0.064, 0.085, and 0.101 wt% carbon contents were analyzed by an opticalmicroscope, optical emission spectrometer, metal in situ analyzer, and electron probe microanalyzer. It was found that microstructuraldelamination occurred due to C and Mn segregation, especially the former. The intensive segregation degree ofC was dependent on its relatively smaller partition coefficient. Moreover, the segregation degree gradually decreased withthe decreasing carbon content. And the increased segregations of elements except carbon were related to the coupling effectbetween different alloying elements. Furthermore, C and Mn were prone to segregate at the 1/4th position along the transversedirection of the casting slab; hence, almost no segregation was noticed at the edge of the casting slab. The homogenizationtreatment had a substantial effect on the elimination of C segregation; however, Mn segregation was relatively hard to beremoved.