The quilting pipe is processed by rolling. Because the surface layer leaves surface residual compressive stress, it helps to close the surface micro cracks and hinder the expansion of erosion. So as to improve the corrosion resistance of the surface, delay the generation or expansion of fatigue cracks, and improve the fatigue strength of quilted pipe. Through rolling forming, a cold work hardening layer is formed on the rolling surface, which reduces the elastic and plastic deformation of the contact surface of the grinding pair, improves the wear resistance of the inner wall of the quilting pipe, and avoids the burn caused by grinding. After rolling, the reduction of surface roughness can improve the matching properties.
Rolling is a kind of chip free processing, which uses the plastic deformation of metal at room temperature to flatten the micro unevenness of workpiece surface, so as to change the surface structure, mechanical characteristics, shape and size. Therefore, this method can achieve the two purposes of finishing and strengthening at the same time, which can not be achieved by grinding.
No matter what processing method is used, there will always be fine uneven knife marks on the part surface, resulting in staggered peaks and valleys.
Rolling processing principle: it is a pressure finishing process, which uses the cold plastic characteristics of metal at room temperature and applies certain pressure on the workpiece surface with rolling tools to make the metal on the surface of the workpiece produce plastic flow and fill it into the original residual low concave trough, so as to reduce the roughness value of the workpiece surface. Due to the plastic deformation of the rolled surface metal, the surface structure is cold hardened and the grain becomes fine, forming a dense fibrous shape, forming a residual stress layer, and improving the hardness and strength, so as to improve the wear resistance, corrosion resistance and compatibility of the workpiece surface. Rolling is a non cutting plastic machining method.
