Abstract

Industrial and laboratory experiments were carried out to investigate the formation and evolution of the inclusions in Ti-bearing Al-killed steel, and thermodynamic calculations were also conducted to check the stability of inclusions in steel. It is found that the addition of Ti influences the inclusions evidently. Before Ti addition, the inclusions transform along the route of “Al2O3 → MgO·Al2O3 spinel → CaO-Al2O3(-MgO) system” with the generation of dissolved Mg and Ca in liquid steel. When there is no sufficient Ca in liquid steel, the addition of Ti during refining process would lead to the transformation of MgO·Al2O3 spinel inclusions into MgO-Al2O3-TiOx inclusions. When a trace of dissolved Ca is formed, CaO-Al2O3-TiOx system inclusions can be generated from MgO-Al2O3-TiOx inclusions or CaO-Al2O3 inclusions. Higher calcium content originated from calcium treatment would result in the formation of CaO·TiO2 inclusions, and then weaken the castability of Ti-bearing Al-killed steel grades. Calcium treatment could also increase the frequency of macro-inclusions in steel, and evidently decline the quality of the steel. Cancellation of calcium treatment is suggested to improve the cleanliness of Ti-bearing Al-killed steel grades.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.