Studies of the decarburisation phenomena during preheating of submerged entry nozzles (SEN) in continuous casting processes

Abstract

PostprintThis is the accepted version of a paper published in Ironmaking & steelmaking. This paper has been peer-reviewed but does not include the final publisher proof-corrections or journal pagination.Citation for the original published paper (version of record):Svensson, J., Memarpour, A., Brabie, V., Jönsson, P. (2016) Studies of the decarburisation phenomena duringpreheating of submerged entry nozzles (SEN) incontinuous casting processes. Decarburisation of the submerged entry nozzles (SEN) during the preheating process was investigated based on plant trials and thermodynamic modelling at three different steel plants. During the trials the preheating processes were mapped, the temperature profiles were registered and post mortem studies of the SENs with scanning electron microscopy (SEM) were performed. Typically, the glass/silicon powder will form a dense and protective layer inside the SEN when heated over 1100°C. However, this study found that the temperature distribution inside the SEN did not always reach this critical temperature. Thus, decarburisation of the SEN was found at all steel plants. The overall results illustrate that the control of the pre-heating process needs to be improved at all steel plants. It is suggested that future research should be focused on the development of new coating materials to prevent decarburisation of the RBM, which would decrease the chances of clogging during casting. Ironmaking

Calculation Accuracy and Efficiency of a Transient Model for Submerged Entry Nozzle Clogging

“…These mechanisms are related to chemistry and thermodynamics of the system. Most studies were made by postmortem analysis of inclusions or clog [13][14][15]30,[39][40][41][42][43] or through thermodynamic calculation of the involved phases (materials) related to clogging. [41,[44][45][46][47] These studies indicated that the clogging event was related to (or affected by) the thermodynamic or chemical properties of the involved materials, but no quantitative correlation between the clogging event and those thermodynamic or chemical properties was established.…”

Optimization on Reducing Slag Entrapment in 150 × 1270 mm Slab Continuous Casting Mold

“…The core concept of high efficiency continuous casting is to produce high quality defect-free steel at high casting speeds. At high casting speeds, slag entrapment in molds seriously deteriorate the quality of steel products, becoming one of the main obstacles affecting the production of high value-added steel products [1].…”

Microstructure, properties, and application of low carbon Al2O3‐C refractories used as submerged entry nozzles

“…1 Excellent thermo-mechanical properties, high corrosion resistance against both liquid steel and slag as well as high thermal shock resistance are typical properties that are required for the application of SEN materials. 1 Excellent thermo-mechanical properties, high corrosion resistance against both liquid steel and slag as well as high thermal shock resistance are typical properties that are required for the application of SEN materials.…”

“…The submerged entry nozzle (SEN) is one of the most important functional components in the continuous casting of steel, playing critical roles in the production efficiency as well as steel quality. 1 Excellent thermo-mechanical properties, high corrosion resistance against both liquid steel and slag as well as high thermal shock resistance are typical properties that are required for the application of SEN materials. To meet these requirements, Al 2 O 3 -C refractories with graphite content in the range of 8%-25%, were developed in the 1980s and have been increasingly used in the continuous casting since then.…”