Analysis of mixed crystal and texture for hot-rolled strip at surface sliver defects
PAN Yi-qing1, YIN Sheng2, TIAN Qing-chao1, PEI Xin-hua2, LUO Ke-li3
1. State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200444, China; 2. Research and Development Center, Shanghai Meishan Iron and Steel Co., Ltd., Nanjing 210039, Jiangsu, China; 3. Hot Rolling Plant, Shanghai Meishan Iron and Steel Co., Ltd., Nanjing 210039, Jiangsu, China
Abstract：The sliver defects of SAE1006 hot-rolled strip were studied to improve the surface quality of hot-rolled products. The defects were analyzed by optical microscope, scanning electron microscope, energy spectrometer, EBSD and X-ray diffraction. The results show that the sliver defects of hot-rolled strip are mainly induced by slag inclusions in continuous casting slabs, which is deriving from the mould slag entrainment in continuous casting process. The reversible rolling of rough rolling stage causes the sliver defects to be folded and reduces the effective strain of surrounding matrix, which leads to the partial recrystallization and mixed crystal. The value of low-angle grain boundaries in mixed-crystal region is as high as 0.074, which is 8 times that of normal part in strip center. The [001] crystal direction appears more frequently in mixed-crystal region, while the crystal direction in the center is mainly [101]. The sliding friction at defected part is large, which tends to produce more shear texture, leading the strength of Goss texture greater than that of normal part, and easy to crack during rolling.
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2022, Vol. 32 
