The rolls of the roll forming machine include work rolls and backup rolls, which are one of the key parts of the roll forming machine and are installed in the roll forming machine. In the production of hot-rolled strip steel, the consumption of rolls is very large, especially the work rolls, which are always in direct contact with the red hot billet. Therefore, to find out the cause of the damage of the roll and make corresponding solutions to improve the life of the roll and reduce the consumption of the roll is a problem that the rolling mill, the manufacturer and the user are very concerned about. In the actual production process, the damage forms of the roll mainly include roll wear, roll crack, roll peeling and roll breakage.
The reasons for roll failure are as follows:
one. Roll wear
Hot rolling rolls have been working in the environment for a long time, in direct contact with the hot steel billet, and are subjected to strong rolling force. Thermal fatigue effect. Therefore, hot rolled materials are required to have the characteristics of high hardenability, low thermal expansion coefficient, high thermal conductivity, high high temperature yield strength and high oxidation resistance.
Second, there are cracks
Cracked rolls should be replaced in time for grinding to ensure a moderate amount of grinding to eliminate residual cracks. In order to reduce or eliminate the internal stress, the work rolls should be subjected to a stress relief annealing after one period of use, or the ground rolls should be immersed in oil with a certain temperature for storage.
Three, roll peeling
Reasonable configuration of roll shape, uniform contact stress between rolls, maintain proper amount of uniform wear, and use the driving effect of wear to effectively eliminate roll peeling. Starting from the rolling process. To ensure the normal input of cooling water, the management of the cooling nozzle of the roll must be strengthened during use to ensure that the nozzle and filter are not blocked, the water volume is sufficient, and the temperature of the roll is controlled within the normal range;
Fourth, the roll breaks
The rolling lubrication technology can also be applied in the production of hot-rolled strip steel. Practice has proved that rolling lubrication can reduce the wear of the roll, reduce the rolling force and rolling torque, relieve the thermal fatigue of the roll, and improve the stress state during rolling. reduce breakage;