Health & Environmental Research Online (HERO)


Print Feedback Export to File
7850697 
Journal Article 
Inter-Columnar Macro-Segregation in Continuously Cast Steel; Characterization, Possible Reasons, and Consequences 
Rajiah, S; Sambandam, M; Shanmugam, SP; Vikraman, S; Taticherla, R 
2021 
0 
Transactions of the Indian Institute of Metals
ISSN: 0972-2815 
74 
7 
1557-1568 
WOS:000646769000001 
The current work emphasizes the characterization of inter-columnar macro-segregation in as-cast samples from continuously cast steel slabs and their segregation level in the rolled products. Based on the literature studies, and understanding from the characterization of steel samples, the formation mechanism and possible causes of inter-columnar segregation have been elucidated. It is observed that macro-segregation happens as a result of the breakage of columnar dendrites in the low ductility region of steel between zero ductile temperature (ZDT) and zero strength temperature (ZST). The external tensile strain has been observed in the form of strain rate due to the cumulative strain of bulging, straightening, and misalignment which exceeds the critical strain of steel causing crack formation at the low ductility region. The inherent critical strain is determined from the interval of ZDT and ZST region which is decided by the segregation of solute elements based on the steel composition. To some extent, the current work elucidates the effect of solute elements on the critical strain and most importantly on segregation of sulphur and phosphorus in liquid has been simulated using Scheil solidification model in Thermo-Calc software. However, the segregation of sulphur leads to the formation of manganese sulphide, whereas steels having a phosphorus level of more than 0.016% enhance the crack formation resulting in inter-columnar segregation, which is in good agreement with the plant data and experimental studies with other researchers.