Elimination of Scratches on the Surface of Welded Pipes
Causes of scratches on the surface of welded pipes (LSAW/SSAW/ERW Pipe): The welded pipe using roll forming requires the strip to be bent into a circle transversely. This is achieved by deforming the strip by a series of rolls with different grooves. Each pair of rolls rotates at a certain speed, but the linear velocity of the roll surface is different due to the radius of rotation. However, the difference in linear speed makes the sliding friction between the strip and the forming roller the root cause of the scratches on the surface of the welded pipe. Most welded pipe mills adopt the horizontal forming method. For this mill, the active roll bottom diameter of the roughing roll, guide ring roll and sizing roll is considered to be the driving diameter, and the linear velocity of these roll bottom diameters is basically equal to the conveying speed of the strip. Due to the different radius of rotation, the roll edge of each roll makes the relative sliding friction between th...