Doctoral Dissertations

Keywords and Phrases

Filtration; Foundry Steelmaking; Inclusion Engineering; Mathematical Modeling; Non-metallic Inclusions; Steel

Abstract

”Ceramic filters are routinely used in steel foundries to remove non-metallic inclusions from steel melt. Removal efficiency for both solid and liquid inclusions by magnesia-stabilized zirconia foam filters (10ppi) were evaluated and distribution of the captured inclusions through the filter thickness was also investigated. A mold design was developed using a commercial computational fluid dynamics software package to produce two castings that fill simultaneously, one with a filter and the other without a filter, from a single ladle pour, while also matching the fill rates and avoid turbulence and reoxidation during pouring. An industrial-scale experiment was also performed to investigate the distribution of captured inclusions through the filter thickness for higher inclusion loading compared to that of laboratory-scale experiments.

Inclusion removal efficiency was observed to be strongly dependent on the initial inclusion concentration. Solid alumina inclusions are found to be captured within the filter at the metal-filter macropore interface. The concentration of the captured solid inclusions decreased exponentially from the entry to exit side of the filter, following first order capture kinetics. Liquid inclusions were captured within the micropores of the ceramic web structure and at the metal-filter macropore interface. The captured liquid inclusion concentration within filter micropores also followed an exponential trend for lower inclusion loading, whereas it became constant for higher inclusion loading due to complete saturation of the ceramic web micropores. Upon filter micropore saturation, continuous liquid inclusion films developed at the metal-filter macropore interface, increasing the possibility for the release of large liquid inclusions from the filter”--Abstract, page iv.

Advisor(s)

O'Malley, Ronald J.

Committee Member(s)

Bartlett, Laura
Xu, Mingzhi
Richards, Von
Mandal, Kamalesh

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Materials Science and Engineering

Comments

The authors wish to gratefully acknowledge the financial support and technical guidance from the industry mentoring committee of Peaslee Steel Manufacturing Research Center, Missouri University of Science and Technology.

Research Center/Lab(s)

Peaslee Steel Manufacturing Research Center

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2020

Journal article titles appearing in thesis/dissertation

  • Removal of alumina inclusions from molten steel by ceramic foam filtration
  • Effect of physical state of non-metallic inclusions on the accumulation within magnesia stabilized zirconia foam filters
  • Ceramic foam filter micropores as sites for liquid inclusion retention

Pagination

xv, 143 pages

Note about bibliography

Includes bibliographic references.

Rights

© 2020 Soumava Chakraborty, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 11778

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