Part of the book: Two Phase Flow, Phase Change and Numerical Modeling
Part of the book: Heat Transfer
Electric-Arc-Furnace (EAF)-based process route in modern steelmaking for the production of plates and special quality bars requires a series of stations for the secondary metallurgy treatment (Ladle-Furnace, and potentially Vacuum-Degasser), till the final casting for the production of slabs and blooms in the corresponding continuous casting machines. However, since every steel grade has its own melting characteristics, the melting (liquidus) temperature per grade is generally different and plays an important role in the final casting temperature, which has to exceed by somewhat the melting temperature by an amount called superheat. The superheat is adjusted at the ladle-furnace (LF) station by the operator who decides mostly on personal experience but, since the ladle has to pass from downstream processes, the liquid steel loses temperature not only due to the duration of the processes till casting but also due to the ladle refractory history. Simulation software was developed in order to reproduce the phenomena involved in a meltshop and influence downstream superheats. Data science models were deployed in order to check the potential of controlling casting temperatures by adjusting liquid-steel exit temperatures at LF.
Part of the book: Dependability Engineering
In the quest for high-quality steel products, the need of cast billets with minimum surface and internal defects is of paramount importance. On the other hand, productivity is required to be as high as possible in order to reduce production cost. Different billet shapes have been applied with emphasis upon square, rectangular, and circular cross-sections. It is obvious that the best billet shape that minimizes surface and subsurface defects is the circular one. Nevertheless, this shape creates some problems with respect to handling and safety reasons. One recent attempt is to produce normal octagonal-shaped billets that appear to approach the circular shape albeit easier to handle. In this study, a numerical solution for the heat transfer during solidification in the continuous casting of octagonal billets has been carried out. The developed model deploys an implicit scheme in order to solve the differential equations of heat transfer under the appropriate boundary conditions in a section of an octagonal billet, assuming fully axisymmetric cooling of the bloom. The geometry of the octagonal billet plays an interesting role in the development of the heat transfer analysis. Based upon fundamental principles, a computer program has been developed for this purpose. Consequently, results from the numerical solution are presented and discussed.
Part of the book: Heat and Mass Transfer