TY - BOOK

T1 - Solidification control in casting of heavy ingots by a novel casting process

AU - Riedler, Michael

N1 - no embargo

PY - 2016

Y1 - 2016

N2 - Within the framework of the FFG-Bridge program the development of a novel casting process for heavy forging ingots (also called Segment Casting) was performed. The investigated technology can be positioned between the well-known casting process, continuous casting and ingot casting. The aim of this development is the combination of certain benefits of both processes. An unaffected solidification leads to qualitative problems due to the unfavourable geometry of the ingot, especially the diameter/height-ratio. Hence the inner quality of the strand will be improved by using electromagnetic stirring as well as hot feeding. At the beginning an evaluation of several parameters from the literature was preformed whereby these parameters should describe the essential inner quality criteria. The main focus here lies on the formation of shrinkage porosities at the centre of the steel strand. Furthermore, laboratory casting experiments with varying cooling conditions and similar d/h-ratio were executed. The performed experiments were numerically illustrated in a model and the different criteria were implemented at this model. A conclusion regarding the validity of the used criteria can be performed based on the comparison of the experimental results with the numerical calculation. Finally, a numerical model of the Segment Casting process was developed, where the electromagnetic stirrer as well as the hot feeder was taken into account. Moreover, the previously determined criteria for the formation of pores were applied on the numerical calculated results. The obtained results point out how the technological parameters of the hot feeder and the electromagnetic stirrer can be adjusted to improve the inner quality of the strand.

AB - Within the framework of the FFG-Bridge program the development of a novel casting process for heavy forging ingots (also called Segment Casting) was performed. The investigated technology can be positioned between the well-known casting process, continuous casting and ingot casting. The aim of this development is the combination of certain benefits of both processes. An unaffected solidification leads to qualitative problems due to the unfavourable geometry of the ingot, especially the diameter/height-ratio. Hence the inner quality of the strand will be improved by using electromagnetic stirring as well as hot feeding. At the beginning an evaluation of several parameters from the literature was preformed whereby these parameters should describe the essential inner quality criteria. The main focus here lies on the formation of shrinkage porosities at the centre of the steel strand. Furthermore, laboratory casting experiments with varying cooling conditions and similar d/h-ratio were executed. The performed experiments were numerically illustrated in a model and the different criteria were implemented at this model. A conclusion regarding the validity of the used criteria can be performed based on the comparison of the experimental results with the numerical calculation. Finally, a numerical model of the Segment Casting process was developed, where the electromagnetic stirrer as well as the hot feeder was taken into account. Moreover, the previously determined criteria for the formation of pores were applied on the numerical calculated results. The obtained results point out how the technological parameters of the hot feeder and the electromagnetic stirrer can be adjusted to improve the inner quality of the strand.

KW - Segment Casting

KW - Gießverfahren

KW - Erstarrung

KW - Modellierung

KW - Simulation

KW - Experiment

KW - Poren

KW - Porositäten

KW - Lunker

KW - Kritrium

KW - Segment Casting

KW - casting process

KW - solidification

KW - modelling

KW - simulation

KW - experiment

KW - pores

KW - porosity

KW - pipe

KW - criterium

M3 - Doctoral Thesis

ER -