Galvanized scratches refer specifically to the scratches formed on the surface of the strip steel on the sinking roll or stabilizing roll during the galvanizing process. Due to the special position of the sinking roll and the fixed roll, the driving device cannot be installed on the sinking roll, and the installation of the driving device on the fixed roll is more complicated, so the sinking roll is almost all driven by the strip steel to run passively, and the fixed roll is also mostly Passive. However, these two types of rollers cannot be installed with ordinary bearing bushes, and can only be replaced with sliding bearing bushes. The resistance is relatively large and the wear is serious, which will have a great impact on their normal operation. If the sinking roll and the fixed roll have high running resistance, the strip steel cannot make it run, and the surface of the strip steel will be scratched. It is characterized in that dense, continuous, deep, and sharp scratches are formed on the entire surface of the strip when the sinking roller does not rotate; when the sinking roller rotates lagging behind, the scratches on the surface of the strip are intermittent , the others are basically the same; the scratches formed on the surface of the steel strip by the stabilizing roll without rotation or lag are basically the same as the non-rotation of the sinking roll, except that the depth is shallower. Since the surface of the sinking roll and the fixed roll is covered with zinc slag, the zinc slag is a fine particle with high hardness. There are many, so the scratches are also dense. The confirmation of this situation is relatively simple. To determine whether it is a problem with the stabilizing roll, you only need to open the stabilizing roll and leave the strip; to determine whether it is a problem with the sinking roll, just use a stick to test the surface of the sinking roll. It can be judged by listening to the sound of the sound bar running on the sunken roller frame.

     When the production line is running normally, the sinking roller or the stabilizing roller does not rotate. The solution is: firstly increase the tension of the process section appropriately, and hit the roller with a stick. If the roller is accidentally stuck for a while, the operation can be resumed. Then use a stick to detect whether the roller is biased to one side, forming axial movement. If there is movement, the roller can be straightened and returned to normal. If it is invalid, the speed-up and speed-down adjustments can be repeated, and the sinking roller and the stabilizing roller may also be restored to operation during the speed-up and speed-down. If the production line produces a thin plate, it can be converted into a thick plate, preferably a thick plate with other defects to move, sink and rotate. If the scratch is only caused by the poor operation of the stabilizing roller, the stabilizing roller can be temporarily loosened to run. If none of the above measures have any effect, it is necessary to consider stopping the machine and changing the roller.

     There are many factors affecting the operation of the sinking roller and the stabilizing roller. If the same problem occurs, after making a comprehensive adjustment to the process, the more stable and quick method is to process the outer circle of the inner sleeve of the bearing bush of the roller into a drum shape. That is to say, in the length direction, the center is large and the two ends are small. When matched with the bearing bush jacket, the contact area is reduced, which can greatly reduce the friction force, and ensure that the roller can run under a small friction force of the strip steel. Problems can be solved quickly to reduce the impact and loss on production.