Solution to High Temperature of Rolling Mill

In summer, we should pay special attention to the safe operation of the rolling mill in the high-temperature natural environment, improve its maintenance and repair, because the temperature rise is more likely to cause small problems of the rolling mill. First of all, the cooling circulating water of rolling mill roll can not be less, the average temperature is high, and the cooling circulating water volatilizes too fast, which should be added frequently. And check the body of water in time, and if the water body smells smelly, it is necessary to dismantle and replace the cooling circulating water, throw away the sewage, replace the saponification liquid again, and add the water that must be accounted for.

If the rolling mill works for a long time, it will also cause the temperature of the motor to rise, so you have to touch the bearing end cover shell of the motor by hand to see if the temperature is too high. If the temperature is high, it needs to be shut down to reduce the temperature of the motor before it works without overload.

The cycloid reducer is used in the rolling mill, and the installation method is inverted. In high temperature, the temperature rise will occur, which makes the viscosity of the lubricating grease lower and lower, and it will flow into the bearing end cover, resulting in the lack of lubricating grease in the cycloid reducer, leading to the temperature rise of the reducer, and the more severe one will burn the reducer. Therefore, it is necessary to often check whether there is a lack of grease in the reducer to ensure the normal operation of the reducer.

In summer, it is also necessary to check the route of household electrical appliances of rolling mills. The rise of average temperature will accelerate the embrittlement of the route, which is easy to cause short-circuit fault. However, the actual operating staff of the rolling mill shall wear rubber gloves during safe operation, and the temperature of spiral gear after cold rolling is too high, which will burn their hands.

In addition, the roll of the rolling mill shall be cleaned. At the end of daily work and after standby, the roll must be removed. Clean the roller surface with a clean towel and wipe off the air oxide skin adhered on the surface, so as to improve the service life of the roller.

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Rolling Mill Packaging, Transportation and Storage Requirements

We have introduced a lot of knowledge about the use and operation of rolling mills. However, if we want to ensure the normal use of the rolling mill machine, we need to comply with certain requirements for its packaging, transportation, and storage. Now we will introduce this aspect for you, hoping to provide a reference. 

First of all, let's take a look at how to properly pack the rolling mill. In general, since the equipment is shipped in bulk during transportation, it is required to wrap the motor part with a plastic cloth during packaging so as to prevent damage due to moisture. In addition, the shaft head of all exposed parts also needs to be wrapped with plastic cloth to prevent damage and corrosion.

As for other parts of the rolling mill, it is necessary to apply antirust oil in advance to avoid rusting in early summer. Therefore, in the process of transportation, what should we pay attention to? When loading, unloading and hoisting the equipment, it is necessary to operate it carefully and ensure that the rope used has sufficient strength. At the same time, it should be noted that the protruding part of the equipment shall not be damaged during lifting, and it is better to use some soft things for protection.

In the process of transportation, it is necessary to ensure that the rolling mill machine is fixed so as to avoid sloshing, and no strong vibration or impact. During the driving process, the speed should be uniform and the driving should be stable. In addition, we also need to pay attention to some problems when storing the product.

When the rolling mill arrives, we need to remove it from the box and check it carefully. The rolling mill equipment is then placed in a ventilated and dry room to prevent rust damage. If long-term storage is required, it should be cleaned and rust-proofed.

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How to Avoid Accidents in Cold Rolling?

In many steel rolling plants, especially in cold rolling production, accidents are most likely to occur, including operation accidents, equipment accidents, and quality accidents. All those directly affect equipment, quality, and output. So when accidents occur, remedies should be taken immediately.

1. The rolling piece is deviated, which usually occurs when the head is worn or the tail deviates when the belt is worn. It is caused by the uneven thickness of the incoming material, unskillful operation, old-fashioned roll holes, electrical problems, etc. The slight deviation during threading can be eliminated by timely adjusting and screwing down; for serious deviation, it is necessary to cut the strip steel in front of the frame, find out the cause of deviation, and then re-thread the strip; if it is found that the strip tail is deviated during tailing off, it is necessary to stop immediately, and lift the screw-down according to the situation to make the strip steel pass or cut it. When rolling a very thin strip, the roll is easy to be damaged due to deviation, so special attention should be paid.

　　

2. The rolling mill runout. Rolling mill runout usually occurs during high-speed rolling of extremely thin strip. Because of the beating, the thickness of the strip fluctuates, it is easy to break the strip. Therefore, once the rolling mill has obvious beating sound, the rolling speed shall be reduced immediately to eliminate the vibration. There are many reasons for the runout, such as high rolling speed, thin product thickness, low rolling pressure and small deformation of the finished pass, large tension before the strip steel, too good or too bad lubrication, insufficient roughness of the working roll, damage of the supporting roll, sudden change of various rolling parameters, large gap between the roll bearing and the bearing seat, etc. The cause of rolling mill vibration is complex and it is not easy to make a correct judgment. Through careful search and analysis, before the correct conclusion is reached, only the method of limiting rolling speed is used to prevent the occurrence of run out. 

2. The broken strip of rolled piece. There are many reasons for the broken strip of the rolled piece. Generally, it can be concluded as four kinds: defective incoming material, poor weld quality, misoperation, electrical and mechanical failure. In case of strip breaking, stop the mill immediately to reduce the loss. Serious belt breaking not only makes the work roll and even the support roll bond seriously, but also makes the treatment of the waste belt and the extraction of the work roll very difficult after bonding. Moreover, the treatment time is long and the labor intensity is large. After the belt breaking treatment, the equipment shall be inspected. The surface quality of the first coil of steel to be rolled after roll change shall be checked carefully. For the coil with weld, the mark of the weld position shall be accurate and clear. The rolling speed shall be reduced before the weld passes through the rolling mill. The steel coil with defects must be rolled slowly to minimize the occurrence of accidents in cold rolling production.

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The Operating Rules of Rolling Mills

Eight Precautions for Rolling Mills

1. Every time the rolling mill appears to be jogging, it must not exceed one second. The worm gear should be adjusted in place, and the adjustment amount should be completely equal on both sides to avoid side bends.

2. When operating the cold rolling mill, there should be a special person to guard, and there should be no phenomenon of no one to guard, so as not to find the equipment failure and not find it in time.

3. Under normal circumstances, a single cold rolling mill should not exceed 40% of the aluminum plate in a single thickness.

4. There must be no debris in the production line.

5. Adjust the amount of reduction and the number of passes according to the material of the incoming material and the capacity of the rolling mill.

6. When using a cold rolling mill, the relevant technical parameters must be in full compliance with the requirements, and it should not be operated under load.

7. Rolls should not be subjected to more serious wear and should be replaced if they are found to be worn out.

8. During the whole rolling process, if the roll affects the surface quality of the rolled piece due to wear, or the size and precision, the roll should be replaced immediately, and after the roll is replaced, the driving operation must be guaranteed 2 to 3 minutes.

Precautions of Cold Rolling Mill

1. Preparation for Startup

Let the rolling mill equipment idle for about 10 minutes. During this period, observe whether the device is running normally, and add lubricating oil and rolling oil to lubricate the equipment properly according to the regulations.

2. Precautions before Unloading

(1) The press should be raised to the specified position, the reel should be retracted into position, and the hydraulic truck should be prepared in advance for auxiliary discharge.

(2) The aluminum plate plug should be inserted into the jaws successfully, otherwise, it will be difficult to insert.

3. Some Considerations

(1) The time for each jog of the machine should not exceed one second. The turbine should be adjusted to reduce the turbine. The adjustment amount on both sides should be equal to avoid the side bend of the rolled piece.

(2) When the cold rolling mill is running, someone should be responsible for guarding to prevent problems.

(3) Generally speaking, the thickness of one rolling of a single cold rolling mill should not exceed 40% of the aluminum plate.

(4) There should be no debris in the production line.

(5) Appropriate adjustments should be made to the pass and reduction depending on the material of the incoming material and the capacity of the rolling mill.

(6) The use of cold rolling mills should meet the requirements of the main technical parameters and should not be overloaded.

(7) The mill roll should not have serious wear and should be replaced if necessary.

(8) In the rolling process, if the wear of the mill roll has affected the surface quality and dimensional accuracy of the rolled piece, the roll should be changed immediately. After changing the roller, it should idle for 2 to 3 minutes.

(9) If there is any phenomenon such as tearing or skewing of the rolled piece, the hand can not be used. It should be stopped first and then taken out.

(10) Rolled finished products or semi-finished products should be filled out with relevant records and stacked in batches.

How to Improve the Operation Efficiency of High-speed Rolling Mill?

High-speed rolling mill is similar to the conventional rolling mill. The ultimate goal is to obtain the required size of the rolled piece by rolling mill calendering. In rolling operation, in order to improve the operation efficiency of the high-speed rolling mill, it is necessary to take corresponding improvement measures.

       

The operation efficiency of high-speed rolling mill is mostly affected by unplanned parking, other equipment delays, roll and bearing replacement, and other process maintenance. Therefore, we need to improve the operation efficiency of the high-speed rolling mill in a planned way. The specific operations are as follows:

1. The material of rolls should be screened according to the requirements of the rolled parts to improve the fatigue strength and service life of the rolls. 

2. Inspect the wear of roll and guide from time to time.

3. Inverse injection process of bearing lubricant from inside to outside to inside, so as to reduce the pollution of dust to bearing.

4. Using ultrasonic technology to inspect and analyze rolls.

5. The dry lubricating oil point has been modified. At present, the dry oil is added from the high-pressure zone. The amount of added oil increases from six cycles of raw materials to eleven cycles, and the thin oil lubrication is a 15-minute cycle. The cumulative effect of these changes can reduce the bearing temperature by several degrees Celsius.

With the upgrading of the steel rolling industry, new problems will arise, and we need to optimize and adjust the rolling process according to the actual situation at any time. This process requires us to explore step by step for a long time.

If you are interested in our rolling mill machine, please feel free to mail at marketing2@hanrm.com, we will make the customized solution for you.

How to Carry out Daily Maintenance of Rolling Mill?

Rolling mills are widely used in the steel industry. In order to ensure the smooth running of daily work, daily maintenance is particularly important. It should be noted that the daily maintenance of the rolling mills will affect the service life. So how to carry out the daily maintenance of the rolling mill, how to operate?

Every day, the rolling mill is inspected for oil, water and gas leakage and overheating of the machine parts; reducing the loss caused by the illegal operation of the equipment or maintenance, and when lifting the rubber rolls, take necessary maintenance measures at the chain, rope and end of the roll surface.

The automatic thickness control system on the rolling mill is operated strictly in accordance with the rolling mill operating process and operating methods. The gearbox should be cleaned at least once a quarter. When the roll is fed to the extreme position, special attention must be paid to the safe operation of the rolling mill. Care should be taken when performing the rolling mill operation to prevent the hand from being pressed by the steel plate and being fed together with the steel. When using the aircraft hoisting mill for inspection, be careful not to collide with the machine.

In the rolling operation, the personnel of each department should coordinate with each other and listen to the command of the person in charge of the rolling mill production line. In the rolling process, the roller and the raceway are in line contact or repaired line contact, and the radial bearing capacity is large and is suitable for bearing heavy load and impact load. If irregular noise is found, such as the abnormal phenomenon that the roller cannot be touched by the sudden release of the load after the steel bar is interrupted, it should be stopped immediately and checked, and the steel rolling production line can be completely stopped before being repaired. After the main drive of the motor is stopped, the upper and lower rolls can be lifted and lowered. When cleaning, firstly, in the hot state, stop the oil drain screw on the side of the gearbox, and turn the rollover of the roll and the lifting of the upper roll.

After the end of rolling, the finished material should be cleared, and the equipment maintenance and repair work should be done. In order to strengthen the effective management of the equipment, the equipment utilization rate should be improved, and the power supply should be turned off in time.