Slab continuous casting by big roll heavy reduction and extra thick plate rolled by low compression ratio
KANG Yong-lin1, ZHU Guo-ming1, JIANG Min1, WANG Guo-lian2, LIU Peng-tao3, XU Hai-wei2, XIE Cui-hong2, WEI Yun-fei2, SHEN Kai-zhao2, LIU Yang4
1. School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China; 2.Shougang Jingtang United Iron and Steel Co., Ltd., Tangshan 063200, Hebei, China; 3.Beijing Shougang International Engineering Technology Co., Ltd., Beijing 100043, China; 4. Research Institute of Technology, Shougang Group Co., Ltd., Beijing 100041, China
Abstract:In recent years, the heavy reduction technology at solidification end of continuous casting developed at home and abroad has achieved good effect on reducing porosity and segregation in thick slab, while there are also some deficiencies, for instance, when the thick slab is pressed by the small rolls of segment, the strain is difficult to penetrate into the core of slab, which is not conducive to ameliorate the central porosity. Obtaining high-quality thick slab with high efficiency, low cost as well as low energy consumption and rolling high-quality thick slab with low compression ratio are still the direction of further exploration and development. In order to solve the problems of central porosity and segregation defects in the solidification process of thick slab continuous casting more effectively, a new technical of wide-thick slab continuous casting by big roll heavy reduction(BRHR) was proposed and the BRHR equipment was developed. The BRHR equipment had been installed, commissioned on the wide and thick slab continuous casting line and operated for more than two years. Meanwhile, the process prediction and control system and secondary cooling water process optimization control technology were developed. The research proves that developed BRHR equipment and technology for continuous casting are conducive to make the reduction strain penetrate into the core of slab. Using the large gradient temperature field which is larger than 500 ℃ or 400 ℃ formed at the end of solidification or just complete solidification (fs=1.0) on the continuous casting line to implement large diameter roll for large reduction can significantly reduce the central defects of wide and thick slab. The production practice proves that shrinkage, porosity and segregation in 400 mm thickness specification wide and thick continuous casting slab have been significantly ameliorated by BRHR equipment and technology. Combined with the optimization of rolling process, the high-quality extra thick slab with thickness of 150-200 mm is produced with very low compression ratio of 1.90-2.53, which has great significance for low cost and short process production of high-quality extra thick products as well as energy conservation and emission reduction.
康永林, 朱国明, 姜敏, 王国连, 刘彭涛, 徐海卫,谢翠红, 魏运飞, 沈开照, 刘洋. 板坯连铸大辊径大压下及低压缩比轧制特厚板[J]. 钢铁, 2022, 57(7): 95-105.
KANG Yong-lin, ZHU Guo-ming, JIANG Min, WANG Guo-lian, LIU Peng-tao, XU Hai-wei, XIE Cui-hong, WEI Yun-fei, SHEN Kai-zhao, LIU Yang. Slab continuous casting by big roll heavy reduction and extra thick plate rolled by low compression ratio[J]. Iron and Steel, 2022, 57(7): 95-105.
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