Speaker
Description
Ultra-Low Carbon (ULC) steel grade is used in automotive industry due to the good formability and a superior surface quality. Titanium is usually added to this grade in order to improve physical properties such as total elongation, normal anisotropy, and strain hardening. However, adding Ti increases clogging tendency comparing Ti-free ULC. For clogging in casting of Ti-ULC steel, two key mechanisms have been proposed: (1) formation of solid oxide due to the chemical reactions on the SEN refractory wall, called ‘early stage’ and (2) deposition of suspended solid non-metallic inclusions (NMIs) on the SEN refractory wall, called ‘late stage’. In this paper a combined model is developed considering both stages. Modeling of early stage is based on the carbothermic reactions inside the SEN refractory and the further reaction of the generated CO gas with the steel melt [1]. Modeling of late stage of clogging is according to clog growth by deposition of the NMIs on the clog front [2]. The combined model is evaluated by comparison with analysis of an as-clogged SEN. The combined model can correlate several parameters, like velocity and pressure of the melt, composition of SEN refractory, size and number density of NMI in the melt, to the clogging tendency in the casting of Ti-ULC.
References
[1] Y.-B. Kang and J.-H. Lee: ISIJ Int., 60 (2020)
[2] H. Barati, M. Wu, A. Kharicha, A. Ludwig: Powder Technol., 329 (2018)