“…Because manganese is segregated in the band structure, a considerable amount of austenite can transform to martensite during the cooling following the isothermal treatment, due to the increased hardenability of austenite. [17,18] Such a microstructure is more brittle than the one wherein hard phases are evenly distributed overall, and, thus, the formation of the band structure does not help to enhance the elongation. Consequently, the manganese content should be controlled at a lower amount in order to restrict the formation of the intercritically annealed for 5 minutes at 840 ЊC, at which the fraction ratio of ferrite to austenite is about 40:60, and then isothermally treated at 465 ЊC, 450 ЊC, and 430 ЊC for 1 and 10 minutes, respectively.…”