| Title |
Joint - Syposium on Fine - Grained Materials by the Phase Transformation Committee ( Eighth ) and the Ferrous Metallurgy Committee ( Second ) : Grain Growth and Modeling ; Effect of Temper Rolling Conditions on the Formation of Abnormally Coarse Grains in |
| Authors |
김교성(Gyo Sung Kim) ; 백승철(Seung Chul Baik) ; 권오준(Oh Joon Kwon) |
| Abstract |
This study was performed to clarify the effect of temper rolling conditions on the formation of abnormally coarse grain(ACG) structure in extra-low carbon steel. Both laboratory and mill trial temper rollings were carried out with various rolling reductions, followed by annealing at temperatures ranging between 660℃ and 700℃ for 3 hours. Optical microstructure and texture were examined using annealed specimens. FEM analysis was also performed to compare the effects of roll diameter, friction, and tension. The ACG was observed when the rolling reduction was higher than a critical value, which was found to be decreased at higher annealing temperatures. The formation of the coarse grains started at the surface layer of the specimens. Crystal orientation was not changed with the development of ACG, but the intensity of texture was decreased. When the rolling reduction was 2%, the ACG could be obtained in the specimens rolled in the mill. However, the ACG was not observed in the laboratory. FEM analyses showed that the discrepency between the two rolling mills was caused by the differences in the roll diameter and the friction coefficient. |