Designing mould fluxes to prevent longitudinal cracking for peritectic steel slab casting

ABSTRACT

During continuous casting of hypo-peritectic steel slabs, control of horizontal heat transfer rate in mould is important to avoid longitudinal cracks. This rate can be manipulated by mould slag crystallization. From an industrial situation where the longitudinal cracking index was too high, a new mould flux was designed with appropriate crystallization kinetics. The mould flux crystallization process was analysed in laboratory through differential scanning calorimetry. The Friedman isoconversional method was applied to determine the activation energy of crystallization from melt. Besides, a new quick test was developed to evaluate crystallization kinetics. The industrial tests have shown that the new mould flux decreases the longitudinal cracking index, and this is related to the decrease of horizontal heat transfer rate during the continuous casting process, which in turn is related to crystallization from mould slag.

KEYWORDS:

• Casting powder‌
• DSC
• horizontal heat transfer
• Peritectic steels
• longitudinal crack
• mould flux
• mould slag
• crystallization kinetics

Acknowledgements

Financial support from the Coordination for the Improvement of Higher Education Personnel of Brazil (CAPES, Finance Code 001) is gratefully acknowledged.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Coordination for the Improvement of Higher Education Personnel of Brazil [Grant Number CAPES, Finance Code 001].