Theme I: Advances in research on modeling of ROT cooling in hot strip mill Chairpersons: N. Nagai (Univ. of Fukui), Y. Serizawa (Nippon Steel)
Cooling technologies in Run-Out-Table (ROT) have important roles as key tools for the controlling of microstructure and mechanical properties of hot rolling. This round-table aims at discussing about modeling of ROT cooling and improvement of controlled cooling technologies, mainly based on achievements of Research Project "Development of heat transfer model of run-out table in hot strip mill, part II" closed at March in 2020.

Theme II: Needs for tubes with uneven thickness and their manufacturing and forming techniques
Chairperson: T. Kuwabara (Tokyo Univ. of Agriculture and Technology), H. Yoshimura (Kagawa Univ.)
There is a demand in the industry for steel tubes with uneven thickness, in which excess tube thickness is reduced as with tailored sheet blanks, to further reduce the weight of transportation equipment such as automobiles. Uneven thickness tubes have locally thickened sections at which the thickness is to be reduced in the second forming process. Another example of uneven thickness tube is that having the thickened ends for pre-reinforced tube joints. In addition, these uneven thickness tubes are highly applicable to non-transport equipment. This session aims to discuss the needs of tubes with uneven thickness and their manufacturing and forming technologies.

Theme III: Understanding plasticity-induced damage evolution: overcoming mechanical problems
Chairpersons: M. Koyama (Tohoku Univ.)
Most steels show fracture after a certain large plastic deformation. A bridge between the plastic deformation and fracture is microscopic damage initiation and subsequent growth. However, behavior of the plasticity-induced damage evolution, which includes hydrogen embrittlement and fatigue etc., is dependent on microstructure, specimen geometry, and loading mode, which thereby has been recognized to be a complex problem associated with both material engineering and mechanical engineering. In addition, microscopic deformation heterogeneity is key to understanding the damage evolution mechanism. Therefore, toward designing further advanced high-strength steels, we must note the positive and negative roles of deformation heterogeneity on the strength, work hardening, and damage evolution. In this opportunity, we aim to find a brilliant future of steels via debating the fundamentals of the plasticity-induced damage and fracture and sharing successful examples of overcoming the plasticity-induced damage problems.