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Introduction

Today, the share of continuous casting in worldwide steel production amounts to more than 90% (appr. 1.5 Billion tons/a). The cc process has a dominating influence on final product quality characteristics. The following topics will be investigated in detail to improve the performance of the casting process as well as the quality of the cast product.

Objectives and Motivation

  • Optimizing the selection and the properties of refractories
  • Investigation and testing of alternative slag band materials
  • Development of alternative mould fluxes
  • Identification of the origin of clogged agglomerates and improve the understanding of the clogging mechanism

Methodology

For the entire objectives one main pillar is the thermochemical simulation with FactSage and mineralogical investigations.

Selection of new slag band materials is based on crucial properties like solubility, oxidation resistance and wetting. Additionally to available information this will be tested both on pure components and readily composed slagband materials.

The development of new mould powder compositions requires laboratory trials. Methods for the determination of the viscosity, the crystallization temperature and the crystal growth rate developed and applied in the previous founding period will we further used.

The origin of clogged material will be investigated by tracing inclusions with tracer elements and the use of oxygen isotope analysis. These activities aim to get a better understanding for the clogging mechanisms for a selected number of highly clogging sensitive steel grades.

In addition an Eulerian-Lagrangian model will be established to calculate the transport phenomenon of the micro inclusions in a turbulent melt flow, to perform the analysis of force Balance. The model will be evaluated in comparison with the laboratory experiments (clogging experiments in induction furnaces). Numerical parameter study on SEN will be performed to investigate the influence of the size, chemistry and morphology of the micro inclusions on the occurrence of clogging.

Results and application

The impact of the tundish lining on steel quality should be quantified, and an optimized matching between lining material and steel grade should support clean steel production.

Further investigations will result in the development of refractory components with superior corrosion resistance for SEN slagbands. In the future an increase of life time of the SEN especially for aggressive mould slags will result from these investigations.

Concerning the clogging phenomenon, the application of new techniques will gain a better insight into the origin of clogged agglomerates and thus provide the basis for laboratory simulation and numerical modelling. As far as most promising combinations of steel grade and SEN will be identified they will be tested in plant trials.