Investigation surface faint-sliver defects of cold-rolling IF steel sheets from slabs produced by continuous casting

摘要

Surface faint-sliver defects of cold-rolling IF steel sheets will have a bad effect on the appearance and use of rolled products. In this paper, it is revealed that Al_2O_3 is the important reason for causing surface faint-sliver defects of cold-rolling IF steel sheets by detecting the inclusion in the strands and analyzing the quality of finished rolled products. Therefore, some methods can be employed to evidently weaken surface faint-sliver defects of cold-rolling IF steel sheets, which include the ladle slag modifier to decrease oxidizability of the ladle slag, high basicity (CaO/SiO_2) refining slag, controlling chemical composition of slag to increase the absorbency of slag to inclusion, improving the clean of steel liquid, decreasing the amount and size of Al_2O_3 inclusion and properly increasing the heating time of strand in heating-furnace.