Papers by Keyword: Faint-Sliver Defect

Abstract: In order to solve the problem of mold powder entrapment which is one of the affecting factors on faint-sliver defect in IF cold-rolled steel sheet in casting process, continuous casting process is optimized. Based on the analysis of the defect, the composition of mold powder is optimized. Otherwise, surface tension and viscosity of mold powder are raised. With theses countermeasures, mold powder entrapment and casting subcutaneous slag is decreased obviously. In addition, the rate of faint-sliver defect in cold-rolled IF steel sheet has been reduced from 5.21% to below 1.0%.

Abstract: The samples of cold-rolled sheets, hot-rolled plates and continuously cast slabs have been analyzed with the condition of faint-sliver defects appeared in IF steel of Pangang, and it was shown that faint-sliver defects in cold-rolled steel sheet were mainly caused by micro-cracks in the surface of strands, slag entrapment in mold during casting and inclusions in sub-surface of strand. Faint-sliver defects were controlled effectively with the technical measures, which were decreasing oxidation of ladle slag, controlling the ratio of CaO/Al2O3 in slag, extending circulation time of deoxidization and alloying in RH process, controlling the casting speed and increasing the viscosity of mold fluxes. Therefore, the ratio of downgrade induced by faint-sliver defects reduced from 10.97% to 1.0%.

Abstract: Mold powder entrapment is one of the affecting factors on faint-sliver defect in IF cold-rolled steel sheet in casting process. Based on the analysis of the defect, the composition of mold powder is adjusted. Otherwise, surface tension and viscosity of mold powder are raised. After taking these measures, mold powder entrapment and casting subcutaneous slag is decreased obviously. In addition, the rate of faint-sliver defect in cold-rolled IF steel sheet has been reduced from 5.21% to below 1.0%.