Theme I: Multi-scale evaluations on microstructures of high-quality iron ore sinters
Chairpersons: M. Hayashi (Tokyo Tech.), R. Murao (Nippon Steel)

CO₂ emission reduction in steelmaking is an important and urgent task for the prevention of grovel warming, and efforts are currently worldwide underway to develop carbon-neutral steelmaking. Improvement of quality such as the reducibility for iron ore sinters leads to a reduction of CO₂ emissions, and energy consumption in the blast furnace process. Improvement of the quality of sinters could be attained by optimization of microstructures. In 2021, the "Multi-scale evaluations on microstructures of high-quality iron ore sinters " research group was established to focus on the Silico-ferrite of Calcium and Aluminum (SFCA) series, which is a constituent phase of sinters and responsible for its high quality. The composition, crystal structure, and morphology of SFCA are still unknown. In the research group, a multi-scale measurement method has been established and applied for the observation of microstructures of sinters, and the relation between compositions, crystal structures, and morphologies of the SFCA series has been elucidated using the multi-scale measurement method. In addition, the effect of compositions, crystal structures, and morphologies of the SFCA series on the reducibility has been studied to clarify what kind of microstructures the sinters should have to attain high reducibility. Phase diagrams of sinters have also been made to control the microstructures of sinters. In this session, the results of the research group and the related results will be presented and discussed.

Theme II: Systems technologies toward enhancing energy efficiency
Chairpersons: H. Suwa (Setsunan Univ.), Y. Yoshinari (JFE Steel)

Total optimization of the steel-process energy chain in steel plants becomes more crucial to solving energy demand and supply problems with uncertainties in steel plants. This discussion session "Systems Technologies toward Enhancing Energy Efficiency," first overviews the pros and cons of conventional "systematic" systems technologies, including the evaluation of life cycle assessment and factory energy management systems, for building green steel-making manufacturing, and then discusses the applicability of "systemic" approaches for the enhancement of not only energy use efficiency but resiliency and sustainability in operating ongoing energy-aware steel-making processes.

Theme III: Tribological studies on steel rolling
Chairpersons: H. Utsunomiya (Osaka Univ.), W. Baba (JFE Steel)

Recently, production of high-strength thin steels increases rolling loads and rolling speed. Research on tribology becomes more important, as the lubrication severely affects rolling phenomena. In this session, tribological studies on rolls and lubrication, oxide scale in steel rolling processes will be presented. Future needs and trends of tribological research on steel rolling will be also discussed.

Theme IV: Research activity on the cooling model for the run-out table in the hot strip mill
Chairpersons: N. Nagai (Univ. of Fukui), Y. Serizawa (Nippon Steel)

Water cooling technology in the steel process is becoming more and more important due to the recent advancement of steel materials. In order to understand the current status of water cooling research and to expand the discussion on future issues, we would like to invite the presenters who have participated in the ROT study group to report on their latest research. In addition, we would like to hear reports and issues from various perspectives from both industry and academia.

Theme V: State-of-the-art research on material modeling
Chairpersons: T. Kuwabara (Tokyo Inst. of Agriculture and Technology), K. Hayakawa (Shizuoka Univ.)

Recently, the manufacturing and processing of steel materials have become more complex and highly precise to great extent. There is a large demand on higher accuracy in predicting the internal structure generated and the deformation and fracture during material processing. In this session, the lectures on modeling and analysis of materials will be delivered by researchers and engineers in industry and academia, to discuss the future trend of this research field.

Theme VI: Multi-phase structures and functionality in galvanized/aluminized coatings by hot-dip galvanizing process
Chairpersons: N. Takata (Nagoya Univ.), M. Ueda (Tokyo Tech.), K. Hoshino (JFE Steel), K. Ishii (Nippon Steel), R. Otomo (Kobe Steel)

In recent years, hot-dip galvannealing (GA) and hot-dip galvanizing (GI) processes are being applied to high-strength steels. Not only cold-forming but also hot-working processes are applied for forming complex shapes of the GA/GI processed high-strength steels, whereby various functionalities are required for the GA/GI processed coatings. Herein, we will share the latest research activities on the chemical reactions and their associated formation of multi-phase structures involved in hot-dip Zn/Al processes, and the various functionalities of the coatings. Each research product will be discussed for understanding the structural factors governing various functionalities of the galvanized/aluminized coatings.