How to prevent roll hazards to improve operational efficiency?

In rolling mill assemblies, rolls operate under chaotic conditions. Residual and thermal stresses are generated during the preparation process prior to production and use of the roll. In use, it is also subjected to a variety of cyclic stresses, including torsion, variation, shear, contact stresses and thermal stresses. The distribution of these stresses along the roll body is uneven and constantly changing. The reason for this is not only the planning elements, but also the continuous changes in roll wear, temperature and roll shape during use. In addition, rolling conditions often exhibit abnormal conditions. If the rolls are not properly cooled after use, they are also harmed by thermal stresses. As a result, in addition to wear, rolls often exhibit a variety of localized and surface damage, such as cracks, crazing, peeling and indentations. A good roll should achieve a good match between strength, abrasion resistance and various other performance indicators. In this way, it is not only in the normal rolling conditions are good, but also in the presence of some abnormal rolling conditions will not cause too much damage. Therefore, when manufacturing rolls, the metallurgical quality of the rolls needs to be strictly controlled or supplemented by external measures to enhance the bearing capacity of the rolls. Reasonable roll shape, through, deformation guidelines and rolling conditions can also reduce the working load of the roll, to prevent some of the peak stress, and extend the service life of the roll. 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 outer surface of the roll body and the core is large. Poor cooling of the rolls at the start of a new rolling cycle, interruption of cooling or overheating of the roll surfaces may cause this temperature difference. The temperature difference between the outer surface of the roll and the core results in large thermal stresses, and when the large thermal, mechanical and residual stresses of the roll exceed the strength of the core of the roll, the roll breaks.

Cold welding recovery method: Cold welder rolls use high frequency electric spark discharge principle for non-thermal overlay welding of metal surfaces, so there will be no deformation, annealing, nibbling and residual stresses, rolling holes and scratches during the recovery of defects, please do not change the state of metal arrangement. High accuracy of calibration. The thickness of the coating is from a few micrometers to several millimeters. It can correct the defects of metal workpieces, such as abrasion, scratches, pinholes, cracks, defects deformation, hardness reduction, trachoma, damage and other functions, only need to be polished and buffed, can also be used for turning, milling, planing, grinding and other machining, as well as plating and other post-treatment.

Leave a Reply

Your email address will not be published. Required fields are marked *