Thermo-fluid model of meniscus behavior and oscillation mark formation in steel continuous casting

The surface quality of steel depends on initial solidification at the meniscus during continuous casting. A computational thermal-fluid model has been developed to simulate the complex transient behavior of the slag layer between the oscillating mold wall, the slag rim, the slag/liquid steel interface, and the solidifying steel shell in the meniscus region. It includes transient heat transfer, multi-phase fluid flow, solidification of the slag and steel, and movement of the mold during several oscillation cycles. The model is validated with transient temperature measurements and shell strand measurements from a “mold simulator” lab experiment and with plant measurements of oscillation mark (OM) depth and slag consumption. Hook type oscillation mark is predicted to form by steel overflowing the meniscus. In addition to the commonly predicted/measured temperature increase during the negative strip time (NST), a smaller temperature increase is predicted during the positive strip time (PST) for thermocouples near steel level, and can be associated with the overflow event. These discoveries help to explain the overflow mechanism in detail and reveal new insights into the phenomena which govern initial solidification, oscillation mark formation, and surface defects in this process.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2017

Author dc:creator

• Yan, Xiaolu

Contributors dc:contributor

• Thomas, Brian G.

• Continuous casting
• Model
• Oscillation mark

Statement dc:rights

• Copyright 2017 Xiaolu Yan

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/97791

OAI record oai:identifier

https://www.ideals.illinois.edu/oai-pmh?verb=GetRecord&metadataPrefix=etdms&identifier=oai%3Awww.ideals.illinois.edu%3A2142%2F97791