Forming mechanism and counter measure of pitting on cold rolled continuous annealed strip steel surface

Abstract

For the pitting defect on the strip surface during cold rolled continuous annealing process, integrated with the equipment and technology, the cause of pitting defect was analyzed and the prevention measures were proposed. The results show that the O2, the dew points in the annealing furnace and the pulling force out of control lead furnace roller to slip and nodule, which are the main reason of the strip pitting. In actual production, the O2 in furnace holds within 0.003%-0.005% and the dew point in the furnace holds within -30--45 ℃, and combined with pulling force control, keep the original strip cleanliness and the furnace roller cleaning online can prevent the strip surface from pitting.