Process control for sliver defects in cold rolled steel sheets
DENG Xiao-xuan1,JI Chen-xi1,WANG Sheng-dong2,GUAN Shun-kuan2,LI Lin-ping3
1. Sheet Metal Research Institute, Shougang Research Institute of Technology, Beijing 100043, China 2. Steelmaking Department, Shougang Jingtang United Iron and Steel Co., Ltd., Tangshan 063200,Hebei， China 3. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China
Abstract：Based on the severe mold entrapment due to the mold splashing and the lack of the basis of the tundish superheat control, the effects of the flow pattern in the mold and the superheat on the surface quality were investigated. It can be concluded that the alumina and mold powder primarily accounted for the slivers defect in this mill and the location of these inclusions were trapped in the first 5 mm of the solidified shell in the upper part of the mold based on the literature review and numerous SEM analysis of steel sheets. Decreasing the gas flow rates and increasing the SEN depth can promote the double roll flow (DRF). Therefore, based on the water model and the industrial experiment, the critical gas flow rates were put forward to control the DRF and the mold splashing was eliminated after applying the results in the real casters. Furthermore, increasing the superheat in tundish can retard the solidification front and decrease the hook depth, thus improve the surface quality of slabs. The tundish superheat in the casting practice was set to 25 to 40 ℃taking into the consideration of steel cleanliness. The degradation ratio decreased from 1.1% to 0.6% after applying these countermeasures.
邓小旋 季晨曦，王胜东，关顺宽，李林平. 冷轧薄板线状缺陷的工艺控制[J]. 中国冶金, 2017, 27(4): 55-60.
DENG Xiao-xuan,JI Chen-xi,WANG Sheng-dong,GUAN Shun-kuan,LI Lin-ping. Process control for sliver defects in cold rolled steel sheets. China Metallurgy, 2017, 27(4): 55-60.
2017, Vol. 27 
