The professional manufacturer of Rolling mill machines talks about the reasons for the breakage of the roll body

According to the professional manufacturer of Rolling mill machines, in practical applications, the rolls of the rolling mill may break. Combined with the analysis of its fracture phenomenon, the main part of the fracture is basically concentrated at the roller ring, and the fracture section is an irregular inclined plane or a vertical section. So, why does this happen?

The analysis of this issue can actually be explained from several aspects. The professional manufacturer of Rolling mill machines believes that, first of all, it may be due to the quality problem 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 greatly with the increase of the roll temperature, 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 collected for analysis, the part of the roll must also have good wear resistance and appropriate hardness and strength at the same time. The professional manufacturer of Rolling mill machines 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 surface of the roll due 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 mill machines said that the hardness standard of the roll is also very important. In general, the hardness is 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 of the roll and the hardness of the roll surface are related to the hardness difference along the diameter direction of the roll body, so it is desirable that the hardness difference along the diameter direction of the roll is as small as possible, and the hardness is moderate.

In the actual rolling work, the rolls will also bear a lot of loads. Professional manufacturers of Rolling mill machines believe that, for example, during the rolling process, the rolls will be affected by the rolling pressure applied by the hydraulic device at both ends, the reaction force generated when the rolling stock is deformed, and will also be subjected to heat and cold variable load, etc.