The casting of titanium stabilized steels with an ultra low carbon content is still a certain challenge for the steel producers because of an increased clogging tendency and both processing and product quality can be affected negatively. The aim of this thesis was to increase the quality and castability of these steel grades at voestalpine Stahl GmbH in Linz. Therefore a statistical evaluation of available process parameters should reveal possible influences on the castability and steel cleanness. This part is based on process parameters which are denoted as significant in the literature, including parameters like total oxygen, processing times and the [Ti]/[Al] ratio. Further on, the formation and morphology of aluminium oxides as well as the influence of the ferrotitanium addition on the nonmetallic inclusions are pointed out in the literature part. In parallel, plant trails with a different ladle slag should reduce the elevated (FeO) content in the slag thus leading to a reduced [Al] burn off. The evaluation of these trials was made by analyzing several slag and steel samples, taken during the secondary treatment of these steel grades. It can be concluded that the changed ladle slag does not lead to a sufficient reduction of the (FeO) content thus no impact on steel cleanness and castability was measureable. On the other hand the quality of the ferrotitanium plays a siginificant role on the cleanness. The oxygen content of the ferroalloy must be significantly higher as it is considered in the literature.
|Translated title of the contribution||Influence of slag practice on the steel cleanness and clogging tendency of ULC-steels|
|Award date||20 Oct 2017|
|Publication status||Published - 2017|
Bibliographical noteembargoed until 05-09-2022
- steel cleanness