A simple, but comprehensive model of heat transfer and solidification of the continuous casting of steel slabs is described, including phenomena in the mold and spray regions. The model includes a one-dimensional (1-D) transient finite-difference calculation of heat conduction within the solidifying steel shell coupled with two-dimensional (2-D) steady-state heat conduction within the mold wall. The model features a detailed treatment of the interfacial gap between the shell and mold, including mass and momentum balances on the solid and liquid interfacial slag layers, and the effect of oscillation marks. The model predicts the shell thickness, temperature distributions in the mold and shell, thickness of the resolidified and liquid powder layers, heat-flux profiles down the wide and narrow faces, mold water temperature rise, ideal taper of the mold walls, and other related phenomena. The important effect of the nonuniform distribution of superheat is incorporated using the results from previous three-dimensional (3-D) turbulent fluid-flow calculations within the liquid pool. The FORTRAN program CONID has a user-friendly interface and executes in less than 1 minute on a personal computer. Calibration of the model with several different experimental measurements on operating slab casters is presented along with several example applications. In particular, the model demonstrates that the increase in heat flux throughout the mold at higher casting speeds is caused by two combined effects: a thinner interfacial gap near the top of the mold and a thinner shell toward the bottom. This modeling tool can be applied to a wide range of practical problems in continuous casters.

http://ccc.illinois.edu/pdf files/publications/03_mtb_meng_con1d_reprint_post.pdf

Heat-transfer and solidification model of continuous slab casting: CON1D

Review of non-reactive and reactive wetting of liquids on surfaces.

Hydrodynamic and hydromagnetic stability

United States. National Aeronautics and Space Administration (NASA MESSENGER Participating Scientist grant NNX07AR77G)

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1002/jgre.20091

The curious case of Mercury's internal structure

The latest publications regarding the development of technology to control inclusion compositions focusing on MgO·Al2O3 spinel inclusions were summarized in this review article. The problems caused by spinel inclusions, which affect practice as well as products were shown. The formation mechanism of MgO·Al2O3 spinel inclusions is secondly explained thermodynamically from the view points of chemistries of molten steels and slag compositions. Furthermore, crystallization behaviour of spinel was introduced. Countermeasures conducted in practices and laboratories were shown along with some problems still left that should be solved in the future.

https://www.jstage.jst.go.jp/article/isijinternational/50/10/50_10_1333/_pdf

Control of MgO·Al2O3 Spinel Inclusions in Stainless Steels

Equilibrium values for the dissolution of solid copper into FeS- Na2S mattes

Droplets of liquid sodium ranging from 1.2 to 2.1 g, immersed in mineral oil, were levitated in an electromagnetic field. The experimental setup was designed and constructed to levitate small metal droplets at audio frequencies. The levitated droplet was found to be very stable inside the inductor, and the equilibrium shape attained by the droplet in the electromagnetic field was measured during the experiment. A surface coupled mathematical model was used to calculate the self-consistent equilibrium droplet shape of liquid sodium under the influence of an electromagnetic field. The predicted shapes of the metal droplet and the position of the droplet inside the inductor compare well with the experimental data.

Levitation of liquid sodium droplets

Virtually all grades of steels exhibit reoxidation during the steelmaking, refining and casting processes. In this paper, reoxidation on the surface of low-carbon, Al-killed steel melts before Ca-treatment was investigated by direct observation of oxide evolution through a confocal scanning laser microscope equipped with a gold image furnace. The formation, growth and clustering of oxides were quantified on molten aluminum-killed steels at different oxygen partial pressures, gas flowrates and temperatures. A scanning electronic microscope (SEM) equipped with an energy dispersive spectroscopy (EDS) system was used to characterize the inclusions formed under different experimental conditions. The time period necessary for observable reoxidation to occur was a function of temperature and also the gas flowrate. A gas-phase mass-transfer of oxygen through a gas boundary layer to the melt surface led to supersaturation and subsequent inclusion formation. The oxide growth decreased at higher experimental temperatures. When the individual crystals were large enough, the capillary depression led to attractive forces over 10 - 1 7 N and consequent particle agglomeration on the surface of steel.

Alan W. Cramb

Papers

Equilibrium values for the dissolution of solid copper into FeS- Na2S mattes

Levitation of liquid sodium droplets

Reoxidation of low-carbon, aluminum-killed steel

(For Use By Financial Assistance Recipients and Non-M&O/M&I Contractors)