Doctoral Dissertations

Keywords and Phrases

Advanced High Strength Steels; Continuous Casting of Steels; Fiber-instrumented Mold; Initial Shell Solidification; Mold Flux Impact; Mold Simulator

Abstract

"Continuous casting of Advanced High Strength Steels (AHSS) is frequently associated with non-uniform shell growth and unstable mold heat transfer caused by complex solidification behavior and mold flux interactions at the meniscus. This dissertation addresses these challenges through the development of a laboratory-scale continuous casting mold simulator integrated with fiber optic sensing and advanced characterization techniques. A static-type dip tester was transformed into a fully instrumented mold simulator capable of reproducing mold oscillation and shell growth. Custom-designed copper molds embedded with Rayleigh backscattered fiber optic sensors enabled high-resolution thermal mapping during initial solidification. Mold flux wetting studies using platinum and graphite crucibles revealed that non-wetting conditions delayed crystallization onset by an average of 143°C. Integrated characterization involving mold simulator experiments, advanced characterization techniques, thermodynamic simulations, shell scanning, and inverse heat conduction analysis was used to investigate peritectic sensitivity in Fe–0.1 wt.% C–Si–Mn steels. Higher Mn contents broadened the effective peritectic range, whereas increasing Si content promoted more uniform shell development. Thermal mapping from fibers identified strong correlations among shell deformation, air-gap formation, and crack initiation, where heat flux surges approaching 3 MW/m² initially followed by reductions to −0.5 MW/m² corresponded directly to crack-prone regions. Preliminary hydrogen sensitivity studies further suggested that elevated dissolved hydrogen levels (~10 ppm) may modify mold flux morphology and heat transfer behavior in peritectic steel grades"-- Abstract, p. iv

Advisor(s)

O'Malley, Ronald J.
Buchely, Mario F.
Emdadi, Arezoo

Committee Member(s)

Smith, Jeffrey D.
Huang, Jie

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Materials Science and Engineering

Publisher

Missouri University of Science and Technology

Publication Date

2026

Journal article titles appearing in thesis/dissertation

Paper I, found on pages 22-46, has been published in Iron and Steel Technology – AIST Transactions.

Paper II, found on pages 47-79, has been published in Materials – MDPI Journal.

Paper III, found on pages 80-123, is intended for submission to Steel Research International Journal.

Paper IV, found on pages 124-162, is intended for submission to Metallurgical and Materials Transaction B Journal.

Paper V, found on pages 163-188, is intended for submission to Metallurgical and Materials Transaction B Journal.

Paper VI, found on pages 189-210, is intended for submission to Steel Research International Journal.

Pagination

xxiii, 227 pages

Note about bibliography

Includes_bibliographical_references_(pages 217-221)

Rights

© 2026 Muhammad Anwarul Nazim , All Rights Reserved

Document Type

Dissertation - Open Access

File Type

text

Language

English

Thesis Number

T 12623

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