Inclusion engineering in Mn-Si de-oxidized steel for thin-strip casting

<p>"The focus of this research was to understand inclusion formation and evolution in Mn-Si de-oxidized steels used in thin-strip casting. Inclusions formation and evolution in ultra-low carbon low-alloyed steels were studied. Inclusion engineering can be used to remove or modify detrimental inclusions, which cause casting issues.</p> <p>The first part of this study focused on inclusion formation as a result of ferro-alloy addition. De-oxidation reaction in steels are the primary source of the typical oxide inclusion formed in steel. For Mn-Si de-oxidized steels ferro-silicon and ferro-manganese are the two ferro-alloys used for de-oxidation. Inclusion formation and evolution during the early stages of dissolution of these ferro-alloys was experimentally studied. The mechanism for inclusion formation in their transient phase was proposed.</p> <p>The second part of this study shows the results of modification of inclusions observed in Mn-Si killed steel as a result of ferro-titanium addition. MnO-SiO₂-Al₂O₃ based inclusions were modified by ferro-titanium addition to form inclusions of lower melting points. These inclusions would cause fewer issues during casting.</p> <p>In the third part of this study a comprehensive dynamic model for vacuum tank degasser (VTD) was developed. VTD is used in the industry to obtain ultra-low carbon steels. Further, VTD processing typically removes gaseous species from liquid steel which is essential for thin-strip casting. Inclusion content in the steel is further reduced by this process. The VTD model calculated thermodynamic equilibrium under different conditions within steel in a ladle during VTD processing. The model successfully predicted composition change in steel over time under VTD processing."--Abstract, page iv.</p>

Name thesis:degree_name

Ph. D. in Materials Science and Engineering

Grantor

Missouri University of Science and Technology

Year dc:date.available

2016

Author dc:creator

• Thapliyal, Vivek

• Ferro-alloy dissolution
• Inclusions
• Steelmaking
• Thermodynamic-modeling
• Thin-strip casting
• Materials Science and Engineering

Repository record dc:identifier

https://scholarsmine.mst.edu/doctoral_dissertations/2397

OAI identifier oai:identifier

oai:scholarsmine.mst.edu:doctoral_dissertations-3399