4 Points About the Steel Rolling Mill You Must Know

What preparatory work should be done before rolling?

For the production of each product, preparations should be made for changing the rolls. In order to make the steel rolling mill run normally, it is necessary to check the position of the roll, the main and auxiliary parts of the rolling mill, and related equipment before rolling. The structure of the rolling mill is different, and the items that need to be inspected are also different. Generally, the items that need to be inspected are:

Roller: Consider the roll orientation after roll jumping;

Rolling mill components: Check various rolling mill components according to technical regulations;

Rolling mill accessories: Check the rolling mill accessories according to the technical specifications and practical experience;

Auxiliary equipment: It is necessary for each auxiliary equipment to be in order.

What are the precautions for trial rolling?

According to the main motor start-up operation management system and the steel rolling mill operation technical operation rules, inform all relevant posts to achieve a safe start-up and safe operation.

Supply cooling water before the operation, and after a period of idling, check whether the rolling mill is operating normally, check whether the temperature rise of various bearings is normal, and check whether there is any abnormal phenomenon of overheating and deformation.

Prepare the trial rolling materials in advance, tap slowly, and do not roll the rolled parts below the specified temperature, so as to avoid tripping the main motor or damage to safety equipment.

During the trial rolling process, measure the standard of each red billet, and check whether the standard is correct and whether the surface quality is excellent according to the adjustment icon. Normal production can only be started after the trial rolling is passed.

What connecting equipment does the steel rolling mill have?

The connecting shaft is a device that transmits power from the gear seat to the roll, or from the roll of one rolling mill to the roll of another rolling mill, or directly from the main motor to the roll. There are two types of universal joint shafts: universal joint shafts and plum blossom joint shafts.

All roll diameters are planned for change. From loading new rolls to roll scrapping, the axis position of the rolls will change up and down, while the axis of the herringbone gear in the gear seat is unchanged. The universal joint shaft allows the axis of the roll to have a large inclination angle (8-10°C) to the axis of the herringbone gear, which can smoothly transmit the turning torque. The allowable inclination angle of the plum blossom shaft is only 1-2 degrees, which is only suitable for rolling mills where the distance between the centerlines of the working rolls does not change much. It is easy to disassemble and change rollers.

The plum blossom connecting shaft and plum blossom bushing should be compatible with the standard of the roll journal so that they can be disassembled when changing the roll, bear a large impact load and extend the service life. The shaft sleeve is generally made of cast iron, and it is made of cast steel in the case of a large force. The joint shaft and the shaft sleeve of the section steel mill with a roll diameter greater than 500mm have a large weight. In order to prevent the weight of the torx joint shaft and the universal joint shaft from acting on the hinge of the torx shaft sleeve or the universal joint shaft, it is usually placed on the joint of the shaft. A shaft bracket is installed in the center to balance the weight of the shaft and make the shaft roll smoothly.

Because the plum blossom joint shaft and the universal joint shaft have their own advantages and disadvantages, a combined joint shaft has recently appeared, that is, the end of the joint shaft and the gear seat is connected by a universal joint shaft, and the end of the joint shaft and the roll is connected by a universal joint shaft. Plum blossom shaft connection. Others include arc gear shafts and so on.

What safety equipment does the steel rolling mill have?

The safety mortar is between the pressing screw of the loading mill and the upper and lower roll bearings and is equipped with a protective cover. When the rolling force exceeds the allowable value, the safety mortar breaks to increase the distance between the rolls, thereby protecting the rolls. The material of the safety mortar is generally hard and brittle cast iron. Its strength should be lower than that of the roll, and cast steel or forged steel cannot be used indiscriminately.

Torx bushing, on the torx head of the loaded roll. When the rolling torque exceeds the allowable changing torque, the plum blossom bushing will break first, and then play the role of protecting the roll.

The coupling is installed at the connection between the shafts of the transmission mechanism. When the motor is overloaded, the pins in the coupling are cut off, and then play a role in protecting the motor.

Overcurrent relay and thermal relay, located at the power input of the motor. When the input current exceeds the load, it can automatically cut off the power supply to protect the motor.