TY - THES

T1 - Systematic Investigation of Mold Level Fluctuation and its Impacts on the Quality of Slabs and Cold Rolled Strips

AU - Trindade dos Santos, Gabriel

N1 - embargoed until 25-02-2025

PY - 2020

Y1 - 2020

N2 - The market requirements on the production of high surface quality steel grades stimulate the measurement and control of the mold level conditions in the continuous casting mold. A considerably turbulent mold top (meniscus) leads to entrapment of casting powder and inclusions, which might seriously compromise the surface integrity of the products. This project aims to evaluate the mold level fluctuation and its consequences on the formation of defects in slabs and cold-rolled strips over the casters at voestalpine Stahl Linz GmbH. More specifically, it seeks to investigate the effects of operational parameters; currently installed hardware and software; change in the Level-2; implementation of the electromagnetic stirring technology on the stability of the steel in the meniscus region and, consequently, on the surface quality. The findings of the study suggest that there are no great differences between the casters in terms of current installed hardware and software. The Level-2 change resulted in no significant influence on the MLF, scarfing index, and slivers formation. The difference in the VUHZ sensor layout seems to impact in the MLF values. MM-EMS has delivered an advantageous impact on the quality of the products. Casting powders and refractory pieces display relevant disparity of performance regarding the formation of surface defects and MLF, respectively.

AB - The market requirements on the production of high surface quality steel grades stimulate the measurement and control of the mold level conditions in the continuous casting mold. A considerably turbulent mold top (meniscus) leads to entrapment of casting powder and inclusions, which might seriously compromise the surface integrity of the products. This project aims to evaluate the mold level fluctuation and its consequences on the formation of defects in slabs and cold-rolled strips over the casters at voestalpine Stahl Linz GmbH. More specifically, it seeks to investigate the effects of operational parameters; currently installed hardware and software; change in the Level-2; implementation of the electromagnetic stirring technology on the stability of the steel in the meniscus region and, consequently, on the surface quality. The findings of the study suggest that there are no great differences between the casters in terms of current installed hardware and software. The Level-2 change resulted in no significant influence on the MLF, scarfing index, and slivers formation. The difference in the VUHZ sensor layout seems to impact in the MLF values. MM-EMS has delivered an advantageous impact on the quality of the products. Casting powders and refractory pieces display relevant disparity of performance regarding the formation of surface defects and MLF, respectively.

KW - Gießspiegelschwankungen (MLF)

KW - Stranggießanlagen

KW - Level-2

KW - Elektromagnetischen Rührtechnologie (MM-EMS)

KW - Flämmanteil

KW - Slivers (OZE)

KW - Mold Level Fluctuation (MLF)

KW - Continuous Casting Machine

KW - Level-2

KW - Multi Mode-Electromagnetic Stirring (MM-EMS)

M3 - Master's Thesis

ER -