The professional rolling mill manufacturer tells the reason for the fracture of the roll body
Release date: 2020-05-16 16:14:16 Visits: 882
According to a professional manufacturer of rolling mills, in actual applications, the rolls of rolling mills may break. Based on the analysis of the fracture phenomenon, the main part of the fracture is basically concentrated at the roll ring, and the fracture section is an irregular inclined plane or vertical section. So, why does this happen?
Analyzing this problem can actually be explained from many aspects. Professional rolling mill manufacturers believe that, first of all, it may be due to the quality problems of the roll itself. Since the work roll is in direct contact with the high-temperature slab and bears various loads, it is required to have good heat resistance. If the hardness of the roll body decreases as the temperature of the roll increases, it means that the heat resistance of the roll is poor, which will seriously affect the overall performance of the roll.
At the same time, if the rolling conditions are analyzed together, the part of the roll must also have good wear resistance and appropriate hardness and strength. The professional rolling mill manufacturer explained that, in fact, the mechanical fatigue of the surface layer caused by the periodic load of the roll, and the thermal fatigue of the roll surface subjected to the periodic heating of the rolling piece and the periodic cooling of the cooling water will cause the wear of the roll and the occurrence of thermal cracks.
The professional manufacturer of rolling mills said that at the same time, the hardness standard of the roll is also very important. Under normal circumstances, its hardness is also inversely proportional to the thermal crack resistance of the roll body. That is to say, the higher the hardness of the roll body, the better the wear resistance, but the weaker its resistance to thermal cracking. Generally speaking, the wear resistance and the hardness of the roll surface are related to the hardness difference of the roll body along the diameter direction. Therefore, it is hoped that the hardness difference along the diameter direction of the roll is as small as possible, and the hardness is moderate.
Finally, in the actual rolling work, the roll will bear a lot of loads. Professional rolling mill manufacturers believe that, for example, in the rolling process, the rolls will be subjected to the rolling pressure from the hydraulic device at both ends, the reaction force generated when the rolled piece is deformed, and it will also bear the alternating load under the action of cold and heat. Wait.
