The working conditions of the rollers in the rolling mill parts are disorderly. The residual stress and thermal stress will occur in the process of roll preparation before production and operation. It is further subjected to various periodic stress effects, including twists and turns, changes, shear, contact stress and thermal stress, etc. . The distribution of these stresses along the roll body is uneven and constantly changing due not only to the planning elements, but also to the wear and tear of the roll, the temperature and the shape of the roll. In addition, the rolling conditions are often abnormal. Roll cooling after use is not appropriate, will also be the harm of thermal stress. So roll in addition to wear, but also often appear cracks, cracking, shedding, indentation and other parts of the damage and appearance damage. A good roller, its strength, wear resistance and other performance indicators should have a better match. In this way, not only in the normal rolling conditions durable, but also in some abnormal rolling conditions when less damage. Therefore, the metallurgical quality of rolls should be strictly controlled or external measures should be taken to enhance the carrying capacity of rolls. Reasonable roll shape, pass, deformation criterion and rolling conditions can also reduce the work load of rolls, prevent partial stress and extend the life of rolls. The reason is related to the residual stress of the roll, the mechanical stress and the thermal stress of the roll, especially when the temperature difference between the roll body and the core is large. This temperature difference can be caused by poor roll cooling, cooling suspension, or overheat of the roll surface at the beginning of a new rolling cycle. This infinite temperature difference between the core and the outer surface of the roll leads to a higher thermal stress, and when the higher thermal stress, mechanical stress and residual stress of the roll exceed the strength of the core, the roll breaks.
        Cold welding repair method: Cold Welding Machine Roll is the use of electric spark high-frequency discharge principle to metal surface non-thermal surfacing, so in the repair roll sand hole, scratches and other defects in the process of no deformation, no annealing, no undercut and residual stress, no changes to the metal arrangement. High Correction Accuracy, coating thickness from a few microns to a few millimeters, can present wear, scratch, pinhole, crack, defect deformation, hardness decline, Trachoma, damage and other shortcomings of the metal workpiece for stacking, sealing, repair and other correction functions, just grinding, polishing, but also for turning, milling, planing, grinding and other types of mechanical processing, as well as electroplating and other post-processing. Cold rolled strip, rolling mill bearings, roll surfacing