engleski

The analysis of defects on continuous cast billets

First the article presents the system of sampling and methods of correction of defects on continous cast billets and rolled steel concrete bars. Although the chemical composition of these billets (with increased contents of manganese and oxygen) is adequate to the standard chemical composition (DIN 488- BSt 500S) there are gas blow holes and cracks as well as central and peripheral segregation. The point is in unsatisfactory deoxidation of hot cracks which develop during solidification. A prove that the hot cracks are decarbonisation in cracks are inclusions of Si, MnS, Fe, S, respectively an increased content of accompanying elements. The hardness value indicates that the rolling process develops regularly, i.e. in the area of recrystallization of metal.

steel ; cast billets ; defects ; segregations ; cracks

Tiskano u: Metalurgija 45 (2006) 3, 196.