How to prevent the harm of roll and improve the working efficiency?

Among the rolling mill components, the working conditions of the rollers are the most disorderly. The residual stress and thermal stress will occur in the preparation process before the roll is made and applied. The application is further subjected to the effect of various periodic stresses, including bending, modification, shear, contact stress and thermal stress. The distribution of these stresses along the roller body is uneven and constantly changing, which is caused not only by planning factors, but also by the constant changes in wear, temperature and roll shape in the application of the roller. In addition, rolling conditions often present abnormal conditions. Improper cooling of the roller after use will also be harmed by thermal stress. So the roller in addition to wear, but also often present cracks, cracking, falling off, indentation and other parts of the damage and appearance damage. A good roll, its strength, wear resistance and other various performance indicators should be a better match. In this way, not only under normal rolling conditions, but also in the presence of some abnormal rolling conditions less damage. Therefore, the metallurgical quality of the roll should be strictly controlled or supplemented by external measures to enhance the bearing capacity of the roll. Reasonable roll shape, pass, deformation criteria and rolling conditions can also reduce the operating load of the roll, prevent part of the peak stress, and extend the roll life. The reason is related to the residual stress of the roll itself, the mechanical stress during rolling and the thermal stress of the roll, especially when the temperature difference between the appearance of the roll body and the core is large. This difference in temperature can be caused by poor roll cooling, cooling stoppage, or roll surface overheating at the beginning of a new rolling cycle. This infinite temperature difference between the appearance and the core of the roll results in greater thermal stress, and when the greater thermal stress, mechanical stress and residual stress of the roll exceed the core strength of the roll, the roll breaks.

Cold welding repair method: the roll of cold welding machine USES the principle of high frequency discharge of electric spark to conduct no heat surfacing welding on the metal surface, so no deformation, no annealing, no edging and residual stress and no modification of the metal arrangement in the process of repairing the roll's sand hole, scratch and other defects. Correction accuracy is high, the coating thickness from several microns to several millimeters, for metal artifacts appear wear and scratches, pinhole, crack, deformation defects and the decrease of the hardness, trachoma, shortcomings and so on damage accumulation, hole sealing, filling peer correction function, only grinding, polishing, also can undertake car, milling, planing, grinding and other kinds of mechanical processing, and post processing, such as electroplating.