Abstract: In view of the pitting defects on the surface of cold rolling continuous annealing strip, the causes of the pitting defects were found out through on-site open furnace inspection, the formation mechanism of the furnace roller nodules was found out by detection the chemical composition of the nodules, and reasonable and effective measures to prevent the furnace roller nodules were put forward based on the equipment and process characteristics of the continuous annealing unit. The results show that the serious roller nodules in the slow cooling section of the annealing furnace are the main cause of the pitting defects on the surface of the strip steel. In the actual production, the occurrence of furnace roller nodules can be effectively controlled by strengthening the cleaning effect of strip steel, optimizing the tension in the annealing furnace, controlling the O₂ content and dew point temperature in the annealing furnace, reducing the roughness of the furnace roller and arranging the production plan reasonably.

Key words: continuous annealing strip steel, pitting defect, furnace roller nodules