Abstract：Surface defects of cold-rolled sheet is an important factor which affecting the material yield of SPHCZ in Han Steel, the main surface defects are long strip surface defects and strip surface warping defects. In order to study surface defects of cold-rolled sheet, the scanning electron microscope , metallographic structure, energy spectrum and other related test methods, the surface defects of cold-rolled sheet were analyzed, and the corresponding solutions had been put forward according to the reasons. The research results showed that: The main components of the strip surface defects are Fe and O, and no other inclusions exist. The reason for this type of strip surface defect was due to the process of rolling steel scale pressed into during the production process. The main components of the strip surface warping defect were the inclusions of Al, K, Na, O. The reason for the warping defect of the strip surface was due to the involvement of the mold powder in the steel during the continuous casting process. The surface defects rate of SPHCZ steel decreased from 0.37% to 0.12% by adopting these measures that increasing the frequency of removing scale, refining the censorship in finishing rolls stand, optimizing the argon blowing system in tundish, increasing the viscosity of mold powder, and so on. It achieved remarkable results.
2019, Vol. 38 