{"id":7295,"date":"2023-04-13T10:50:51","date_gmt":"2023-04-13T02:50:51","guid":{"rendered":"https:\/\/lmmrolls.com\/?p=7295"},"modified":"2023-04-13T10:53:06","modified_gmt":"2023-04-13T02:53:06","slug":"10-places-you-need-to-pay-attention-to-during-rolling-process","status":"publish","type":"post","link":"https:\/\/lmmrolls.com\/hi\/10-places-you-need-to-pay-attention-to-during-rolling-process\/","title":{"rendered":"10 places you need to pay attention to during rolling process"},"content":{"rendered":"

Kata kunci<\/strong>\uff1aRolling process, billets, \u092e\u093f\u0932 \u0930\u094b\u0932<\/a><\/p>\n\n\n\n

Keterangan<\/strong>\uff1a<\/p>\n\n\n\n

Rolling is a process in which metal bars, plates, profiles, etc. are deformed through continuous stress to obtain the required shape and size. In this process, you should pay attention to the following places to ensure the quality and performance of metal materials<\/p>\n\n\n\n

\"10<\/figure>\n\n\n\n

Strip steel (strip billet) warped head<\/strong><\/h2>\n\n\n\n

1. Causes:<\/strong><\/p>\n\n\n\n

\u2460The temperature difference between the upper and lower surfaces of the billet: when the temperature of the upper surface is higher than the temperature of the lower surface, it will cause buckle of the strip, otherwise it will cause warping of the strip;<\/p>\n\n\n\n

\u2461Elevation of the rolling line: If the elevation of the rolling line is too high, it will cause buckling of the strip, otherwise it will cause the strip to warp;<\/p>\n\n\n\n

\u2462Influence of friction factors: When the surface of the strip steel is not descaled or the roll is rough, the strip steel will bend to the side with the iron sheet or the rough surface of the roll surface, which will cause the strip steel to warp or buckle;<\/p>\n\n\n\n

\u2463Influence of the rolling pressure of the roller system: when the upper rolling is used, the strip will be buckled; if the lower rolling is used, the strip will be warped;<\/p>\n\n\n\n

\u2464 Influence of rolling speed: When the roll surface speed of the lower roll is greater than the speed of the upper roll, it will cause the warping of the strip, otherwise it will cause buckling;<\/p>\n\n\n\n

\u2465Unreasonable distribution of rolling load.<\/p>\n\n\n\n

2. Preventive measures:<\/strong><\/p>\n\n\n\n

\u2460 Reasonably arrange the heating system to ensure the heating temperature of the billet, the temperature difference between the upper and lower surfaces, and the temperature difference between the core and the outer surface \u2264 30 \u00b0 C; the rolling process maintains a reasonable rolling rhythm, and at the same time ensures the uniform cooling of the roll system;<\/p>\n\n\n\n

\u2461Replace the backing plate in time according to the elevation of the rolling line and the technical requirements of the backing plate of the rolling mill;<\/p>\n\n\n\n

\u2462Guarantee the descaling effect of coarse descaling and fine descaling. Coarse descaling water pressure \u2265 16MPa, fine descaling water pressure \u2265 18MPa;<\/p>\n\n\n\n

\u2463Use the upper roller under the condition that the elevation of the rolling line meets the requirements.<\/p>\n\n\n\n

3. Processing method:<\/strong><\/p>\n\n\n\n

\u2460Slow down the rolling rhythm;<\/p>\n\n\n\n

\u2461Adjust the difference between the heating temperature of the upper and lower surfaces of the billet;<\/p>\n\n\n\n

\u2462 Check whether the cooling system of the roll is blocked;<\/p>\n\n\n\n

\u2463 Readjust the load current of each rack and each pass;<\/p>\n\n\n\n

\u2464When the head warping is serious, the roll should be replaced in time (adjust the roll pressure, rolling elevation and properly reduce the height of the upper guard plate at the exit.)<\/p>\n\n\n\n

Scrap steel<\/strong><\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460 The thickness of the slab is uneven, there are side bends, etc., or the incoming material of the rough-rolled strip is not straight, which leads to inconsistent extensions on both sides of the strip after entering the finishing mill;<\/p>\n\n\n\n

\u2461The accuracy of pressing and leveling after changing the rolls<\/a> is not high, resulting in large deviations in the gap between the rolls on both sides;<\/p>\n\n\n\n

\u2462Depressing the hand did not make timely and correct adjustments to the change of the material shape of the strip;<\/p>\n\n\n\n

\u2463 The center line of the opening of the guide is not centered or the opening is too large, causing the strip to deviate;<\/p>\n\n\n\n

\u2464 The roll gap of the rolling mill is out of position, and the operator did not confirm this in place and did not adjust it in time, resulting in partial scrap steel;<\/p>\n\n\n\n

\u2465 The roll body loses meat, and the material is biased when pressed into the strip;<\/p>\n\n\n\n

\u2466 Insufficient roll turning accuracy, such as material deviation caused by roll taper, out-of-roundness or three-point difference exceeding the process index;<\/p>\n\n\n\n

\u2467 Debris left on the rolling line, such as wrenches and leveling discs, etc. affect the strip threading process and cause material deviation.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 The operator should observe the shape of the slab and the rough rolling material frequently, and adjust it in time if there is any change, so as to ensure the straightness of the finishing rolling material;<\/p>\n\n\n\n

\u2461Strengthen the sense of responsibility, and be meticulous and careful during the leveling process to ensure the quality of leveling;<\/p>\n\n\n\n

\u2462Depress the hand to improve its own operating skills, and quickly and accurately adjust the changes in the shape of the strip steel;<\/p>\n\n\n\n

\u2463 Use the time of succession inspection and roll changing time to measure the guides and guards to ensure that the guides and guards are centered and the size of the opening of the guides and guards on each rack meets the process requirements;<\/p>\n\n\n\n

\u2464If you find that the roll gap is out of position, you should contact the automation personnel and other relevant personnel in time. If you have not confirmed whether the roll gap is true or false, you should stop and check, and you should not have a fluke mentality of gambling to prevent unnecessary steel scrap;<\/p>\n\n\n\n

\u2465Strictly implement the process discipline to ensure uniform cooling of the roll body. And use the shift or waiting time to carefully check the roll surface;<\/p>\n\n\n\n

\u2466The rolling section must ensure the machining accuracy of the rolls, and at the same time, the steel rolling section must check and confirm the roll surface of the upper machine roll;<\/p>\n\n\n\n

\u2467 Strengthen the inspection of equipment and process.<\/p>\n\n\n\n

3. Processing method:<\/p>\n\n\n\n

\u2460Turn off the cooling water of the rolls in time, and quickly lift the roll gap to prevent the rolls from being partially heated to cause cracking defects;<\/p>\n\n\n\n

\u2461 After the scrap steel is processed, the roll surface should be inspected first to see if the scrap steel sticks to the roll, loses meat, etc.;<\/p>\n\n\n\n

\u2462 Re-level the rolling mill;<\/p>\n\n\n\n

\u2463Whether the measuring guide meets the requirements of the process;<\/p>\n\n\n\n

\u2464 If there is a problem with the roll, it should be replaced in time.<\/p>\n\n\n\n

On the wall<\/strong><\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460 The adjustment of the material shape of the strip steel by pressing down the hand is not in place, so that the strip steel deviates during the belt threading process, causing the head to hit the wall;<\/p>\n\n\n\n

\u2461 The operation is not careful, the speed hand cannot observe the strip threading process in place, and does not cooperate with the pressing hand to adjust the speed in time, so that the amount of sheathing between the racks is too large, causing the middle part, especially the tail, to hit the wall.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 The rough rolling operator should adjust the strip in time to prevent the material shape of sickle bend and S-shaped bend, and ensure that the upstream plate shape is good;<\/p>\n\n\n\n

\u2461Finish rolling operators strengthen their sense of responsibility and make careful adjustments.<\/p>\n\n\n\n

\u2462 There must be a tacit cooperation between pressing and speed, especially when wearing the belt at the head and throwing steel at the tail, the speed hand must be cautious.<\/p>\n\n\n\n

3. Processing method:<\/p>\n\n\n\n

\u2460 Press down the hand to adjust the roll gap of the previous frame to make the strip straight;<\/p>\n\n\n\n

\u2461 The speed hand cooperates with the lower hand to try to reduce the speed of the upper rack correspondingly, and a certain tension is generated between the two racks on the upper wall, so that the strip steel “goes down the wall”.<\/p>\n\n\n\n

\u2462Once the wall occurs, the scrap steel shall be cut and processed in time, and the production shall be resumed quickly.<\/p>\n\n\n\n

Broken roll<\/strong><\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460Rolling low-temperature steel: The heating temperature system is unreasonable. After heating, the billet has black marks on the water pipe or the temperature is too low, and the head of the billet is poured with descaling water. And cause the roll to break;<\/p>\n\n\n\n

\u2461Foreign matter brought in: the wrench, block, etc. left on the rolling line during maintenance or daily maintenance are brought into the rolling mill by the strip steel for rolling, resulting in partial concentration of the rolling force, resulting in roll breakage;<\/p>\n\n\n\n

\u2462Strip deviation: the operator is not careful in seasoning, causing the strip to deviate to one side of the roll, causing the roll to be broken due to excessive local load;<\/p>\n\n\n\n

\u2463Unreasonable load arrangement of the rolling mill: the unreasonable load distribution among the rolling mills makes one of the rolling mills bear too much load, which exceeds the maximum torque of the \u0930\u094b\u0932\u093f\u0902\u0917 \u092e\u093f\u0932 \u0930\u094b\u0932<\/a> and causes fracture;<\/p>\n\n\n\n

\u2464 Backing plate displacement of the rolling mill: during the pressing or normal rolling process, the roll is broken due to the excessive deviation of the actual rolling force on both sides caused by the displacement of the backing plate;<\/p>\n\n\n\n

\u2465 Roll cooling is not in place: the cooling water is not opened or the water nozzle is blocked, which leads to the fracture of the thermal stress caused by the excessive temperature or uneven temperature of the roll along the length of the roll body;<\/p>\n\n\n\n

\u2466The quality of the roll itself: the defects of the casting structure and heat treatment structure of the roll, which cannot meet the normal rolling conditions during use, are fractured;<\/p>\n\n\n\n

\u2467 Influence of the fatigue layer of the roll: After the used roll is turned, there are still fatigue cracks that expand during use, and the fracture occurs when the load is heavy;<\/p>\n\n\n\n

\u2468The roll is broken due to the excessive rolling force caused by the overlapping rolling of the strip steel.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 Strictly implement the process discipline, and there should be no luck;<\/p>\n\n\n\n

\u2461Strengthen the point inspection of equipment, especially to thoroughly inspect various production process parts before maintenance and rolling;<\/p>\n\n\n\n

\u2462 The operator must operate carefully to ensure the straightness of the material shape. To prevent the steel strip from warping or sheathing, resulting in overlapping rolling of the steel.<\/p>\n\n\n\n

\u2463 Distribute the load of each rolling mill in strict accordance with the regulations;<\/p>\n\n\n\n

\u2464 Understand the usage degree and wear condition of the shim iron, and replace the matching shim iron in time when there is a problem;<\/p>\n\n\n\n

\u2465Intensify the inspection of equipment, and timely feedback and solve problems found;<\/p>\n\n\n\n

\u2466 Ensure that the cooling water nozzle is not blocked, and at the same time, understand the working conditions of the rolls used in the machine to prevent the phenomenon of skewed rolls, burnt boxes, burnt rolls and roll surface cracks.<\/p>\n\n\n\n

3. Processing method:<\/p>\n\n\n\n

\u2460 Notify the roll to prepare the roll;<\/p>\n\n\n\n

\u2461Organize on-site handling of broken rolls, and take corresponding measures to take out the broken rolls according to the site conditions such as the location of the broken rolls, the degree of breakage, etc.;<\/p>\n\n\n\n

\u2462Find the cause of the broken roll and solve it in time to prevent the roll from breaking again.<\/p>\n\n\n\n

Bad shape<\/h2>\n\n\n\n

1. Cause: along the rolling direction, there are wavy bending defects with ups and downs.<\/p>\n\n\n\n

\u2460The reason for side waves: According to the different parts of the wave distribution on the steel belt deck, the waves distributed on one side of the deck are called unilateral waves; the waves distributed on both sides of the deck are called bilateral waves. The elongation of the strip along the width direction is inconsistent, mainly due to the thickness difference before rolling, the roll is not leveled, the degree of wear in the direction of the roll body is inconsistent, the deviation of the strip steel and the uneven cooling of the length of the roll body are all caused. Causes of strip edge waves;<\/p>\n\n\n\n

\u2461Cause of intermediate waves: The defects distributed in the middle of the plate surface along the rolling direction are called intermediate waves. The main reason is that the convexity produced by the thermal expansion of the roll is greater than the deflection value of the roll under the action of the rolling force during the rolling process; in addition, the load distribution between the stands is unreasonable, and the load of the last stand rolling mill is too small. To some extent, it caused an intermediate wave;<\/p>\n\n\n\n

\u2462Causes of side bending: thickness difference of strip steel, temperature difference and working status of pressing screws, etc.;<\/p>\n\n\n\n

\u2463 The reason for the serpentine bend: the main reason is that the strip difference of the strip is large, the degree of control of the heating temperature and the degree of wear and levelness of the roll system of the finishing mill are all influencing factors;<\/p>\n\n\n\n

\u2464 Defects in the equipment, such as: deformation of the transmission shaft, loose anchor bolts, unstable frame, etc. will affect the change of the plate shape.<\/p>\n\n\n\n

\u2465The roll shape of the roll is bad, and the roll is conical, drum-shaped, or spindle-shaped; the rolling volume of the roll is too large, and the roll cannot be changed in time;<\/p>\n\n\n\n

\u2466The suppression system is unreasonable. The rear frame, especially the finished frame, has too much or too little reduction;<\/p>\n\n\n\n

\u2467 The roll level is not good, or the cooling temperature is uneven;<\/p>\n\n\n\n

\u2468 The roll shape and the plate shape are inconsistent;<\/p>\n\n\n\n

\u2469 Improper operation adjustment or misoperation.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 To ensure the leveling accuracy of the rolling mill, the operator should adjust in time to ensure the flatness of the plate shape change of the strip when the operator finds it, and ensure that the cooling water of the roll is evenly distributed;<\/p>\n\n\n\n

\u2461 Reduce the rolling rhythm, increase the speed of rolling, and minimize the pure rolling time, thereby reducing the temperature rise of the rolls and ensuring uniform cooling of the rolls; reasonably adjust the temperature of each stand according to the difference between the deflection of the rolls and the thermal crown of the rolls. load distribution;<\/p>\n\n\n\n

\u2462Operators should adjust the plate shape changes in a timely and correct manner; strengthen the spot inspection of equipment, and carry out technical reforms for unreasonable places;<\/p>\n\n\n\n

\u2463Strictly implement the process discipline, and burn steel according to the heating process system;<\/p>\n\n\n\n

\u2464 Guarantee the grinding accuracy of the rolls, strengthen the inspection of equipment, and timely feedback and deal with existing problems;<\/p>\n\n\n\n

\u2465Adjust the levelness of the roll to ensure that the cooling water of the roll is evenly distributed;<\/p>\n\n\n\n

\u2466Appropriate original roll shape can be selected, which can reduce the influence of bad shape defects to a certain extent.<\/p>\n\n\n\n

3. Processing method:<\/p>\n\n\n\n

\u2460 Check the material shape of the upstream rack and adjust it carefully;<\/p>\n\n\n\n

\u2461 For the rolls that are seriously worn due to the long working period of the rolls, the rolls should be replaced as soon as possible;<\/p>\n\n\n\n

\u2462 Check various influencing factors on site, analyze the causes of defects, and reasonably select work rolls with convexity and concavity according to the actual situation to ensure the quality of the roll profile.<\/p>\n\n\n\n

\u2463Optimize the reduction system, and the distribution of the reduction amount of each frame should be reasonable;<\/p>\n\n\n\n

\u2464The operator should carefully observe the rolling situation, control and adjust in time, and operate finely.<\/p>\n\n\n\n

Can’t pull out the roller<\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460 Press down the screw and it is not in place;<\/p>\n\n\n\n

\u2461 The exit guard board is not removed;<\/p>\n\n\n\n

\u2462The removal of the entrance guide is not in place;<\/p>\n\n\n\n

\u2463 The water retaining plate is not removed;<\/p>\n\n\n\n

\u2464The thermal expansion of the roll and the thermal expansion of the flat head of the \u0930\u094b\u0932\u093f\u0902\u0917 \u092e\u093f\u0932 \u0930\u094b\u0932<\/a>;<\/p>\n\n\n\n

\u2465Insufficient hydraulic cylinder pressure;<\/p>\n\n\n\n

\u2466 The two connecting shafts are unbalanced, or the flat head of the roll does not match the sleeve of the connecting shaft;<\/p>\n\n\n\n

\u2467 The gap between the roll and the rolling mill archway is full of sundries, such as iron oxide scale, round steel for leveling, disc circle, etc.;<\/p>\n\n\n\n

\u2468The roll is off the way or the work roll is tilted when the roll is drawn, causing the bearing box to be stuck;<\/p>\n\n\n\n

\u2469 The bending cylinder is not reset. The lifting track did not go up in place<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 Strictly implement the operation rules for changing rolls, and resolutely put an end to illegal operations;<\/p>\n\n\n\n

\u2461 When new rollers are installed, oil must be applied to the copper sliding plates of each bearing box;<\/p>\n\n\n\n

\u2462 Strengthen the inspection of the connecting shaft sleeve liner to prevent falling off.<\/p>\n\n\n\n

3. Take measures:<\/p>\n\n\n\n

\u2460 Make sure that the hydraulic cylinder is pressed down and lifted when changing rolls so that there is a certain gap between the upper support roll and the work roll;<\/p>\n\n\n\n

\u2462The hydraulic fitter should confirm the hydraulic system of the rolling mill before changing rolls;<\/p>\n\n\n\n

\u2463 When changing rolls, set the position of the two joint shafts to the state of “two joint shafts in balance”;<\/p>\n\n\n\n

\u2464 The sundries in the rolling mill archway should be cleaned up in time when changing rolls or overhauling;<\/p>\n\n\n\n

The loading roller cannot be loaded<\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460The roller head is not aligned with the flat head of the connecting shaft, the two connecting shafts are parallel, or the chuck is not tightened when the roller is pulled out, resulting in the falling of the connecting shaft;<\/p>\n\n\n\n

\u2461 The flat head inner liners of the upper and lower connecting shafts fell off, causing the roller heads not to be installed in place;<\/p>\n\n\n\n

\u2462The thickness of the copper plates on both sides of the bearing box is too high, the position of the bearing box fat or the copper plate is not in line with the position of the lower balance beam of the frame, and the flat head fat causes the roller to not fit in;<\/p>\n\n\n\n

\u2463 The bevel angle of the backing plate of the machine seat is not enough or the backing plate is out of position so that it cannot be installed;<\/p>\n\n\n\n

\u2464 The roll is not put in place, causing the roll to tilt as a whole or the roll to fall off the track, so that the bearing box can not be installed against the frame;<\/p>\n\n\n\n

\u2465The entrance guide is not moved out in place or the position of pressing down the screw is not high enough;<\/p>\n\n\n\n

\u2466Rolls of different racks cannot be mixed.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 When changing the roll, confirm that the position of the chuck is tightened, and at the same time, ensure that the roll head of the upper machine roll is in the same position as the flat head of the two connecting shafts;<\/p>\n\n\n\n

\u2461 Check whether the flat head inner lining is normal before installing the roller;<\/p>\n\n\n\n

\u2462Guarantee the dimensional accuracy and process requirements of the bearing box, flat head and inner lining of the archway;<\/p>\n\n\n\n

\u2463Replace the backing plates that are severely worn or cannot meet the normal use in time;<\/p>\n\n\n\n

\u2464 Check whether the four positioning pins under the roll bearing box are placed in place, the size of the positioning pin exceeds the standard, and whether the roll is off the road, etc.;<\/p>\n\n\n\n

\u2465 Confirm the various process parts when loading the roll, and determine the lifting height of the pressing screw according to the different roll diameters of the loaded roll;<\/p>\n\n\n\n

\u2466Execution of strict process discipline, install the machine according to the order of roller matching.<\/p>\n\n\n\n

3. Treatment measures:<\/p>\n\n\n\n

According to the on-site situation analysis and elimination of influencing factors, check whether there are obvious traces of friction on the copper slide plate and flat head of each bearing box, and then grind or replace another new roll immediately.<\/p>\n\n\n\n

Pull steel<\/strong><\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460 The unreasonable speed distribution between the racks leads to a large extension in the width direction of the strip, which makes the strip narrow;<\/p>\n\n\n\n

\u2461 When the specification is changed, the adjustment operation is not timely, the speed and the pressing are inconsistent or misoperation, etc.;<\/p>\n\n\n\n

\u2462During the rolling process, when the material is biased or the wall is on the wall, the steel drawing caused by reducing the speed of the rolling mill is adopted;<\/p>\n\n\n\n

\u2463The setting of speed ratio, hysteresis setting of the unit and the tension and angle setting of the looper setting are unreasonable;<\/p>\n\n\n\n

\u2464 Steel drawing caused by equipment reasons, such as: looper failure, sudden reduction in rolling mill speed, etc.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 The parameters of the operating procedures must be memorized, and the load and speed of the grid rolling mill shall be reasonably distributed in strict accordance with the process system;<\/p>\n\n\n\n

\u2461 When changing specifications, analyze the reduction of each frame to confirm the range of speed adjustment; when adjusting, notify each other and cooperate consistently;<\/p>\n\n\n\n

\u2462Strengthen the spot inspection of equipment and carefully operate to ensure the normal operation of the equipment;<\/p>\n\n\n\n

\u2463 Set various parameters according to the regulations.<\/p>\n\n\n\n

3. Treatment measures:<\/p>\n\n\n\n

The measurer should be notified in time to change the specification, wait for judgment or downgrade. For the head tension steel, the core can be pulled to minimize the loss.<\/p>\n\n\n\n

Roll gap movement<\/strong><\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460Automatic magnetic scale problem, the reading is not accurate;<\/p>\n\n\n\n

\u2461 There is a problem with the clutches on both sides of the pressed motor, the separation and separation are not flexible or the gap is large;<\/p>\n\n\n\n

\u2462The brakes of the pressing system on both sides are loose;<\/p>\n\n\n\n

\u2463 There is a problem with the brush of the vertical roller clutch;<\/p>\n\n\n\n

\u2464 The hydraulic pressure on both sides is unbalanced, causing the roll to tilt;<\/p>\n\n\n\n

\u2465 The bearing box of the upper support roll or the upper work roll is fat, causing certain jamming.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460Intensify inspections, communicate with automation personnel, and solve problems in a timely manner; \u2461Replace severely worn parts in a timely manner;<\/p>\n\n\n\n

\u2462Communicate with the fitter, and solve it in time when overhauling or changing rolls;<\/p>\n\n\n\n

\u2463Ensure the machining accuracy of the bearing housing.<\/p>\n\n\n\n

3. Processing method:<\/p>\n\n\n\n

\u2460 When the roll gap is found to be out of position, it must be confirmed first, and the material shape should be observed to see whether the data displayed by the computer is true;<\/p>\n\n\n\n

\u2461 If there is a problem, stop the rolling as soon as possible, and contact the automation personnel at the same time to troubleshoot the fault.<\/p>\n\n\n\n

Roll injury<\/strong><\/h2>\n\n\n\n

1. Causes:<\/p>\n\n\n\n

\u2460 The impact of the fish head and tongue tail of the steel strip on the low-temperature irregular shape of the roll will produce certain roll marks on the roll surface;<\/p>\n\n\n\n

\u2461 The unreasonable position of the upper and lower guard plates causes excessive wear on the rolls, resulting in damage to the strip loading rolls in the longitudinal middle of the strip;<\/p>\n\n\n\n

\u2462Under the alternating stress and thermal stress, the expansion of micro-cracks on the roll surface causes the roll surface to partially fall off;<\/p>\n\n\n\n

\u2463 Roll damage caused by periodic changes in the transverse direction of the strip caused by longitudinal and transverse textures or meat loss on the roll surface due to poor cooling of the roll body during use;<\/p>\n\n\n\n

\u2464 The damage to the roll surface caused by the disc circle or iron bar pressed in during the leveling process causes the roll damage of the strip steel on the length of the pass bar, and the damage to the roll caused by the introduction of foreign matter during the rolling process;<\/p>\n\n\n\n

\u2465 The collision of the rolls during the hoisting process, and the scratches on the surface of the work rolls by the support rolls or the bearing boxes due to the failure of the roll changer to confirm the position of the rolls when the work rolls are installed, resulting in scratches on the surface of the strip steel Periodic transverse roll damage occurs on the surface;<\/p>\n\n\n\n

\u2466 There are defects in the back-up rolls, and roll damage caused by uneven wear on the work rolls during the rolling process;<\/p>\n\n\n\n

\u2467 Damage to the surface of the feed roller, free roller or pinch roller caused by some uncertain factors during maintenance or routine maintenance, and scratches on the strip by some dead rollers on the roller table;<\/p>\n\n\n\n

\u2468There are quality defects in the roller itself, such as trachoma defects in the casting process.<\/p>\n\n\n\n

2. Preventive measures:<\/p>\n\n\n\n

\u2460 Cut the head and tail of the low-temperature irregular head and tail of the strip;<\/p>\n\n\n\n

\u2461 Ensure that the angles of the copper tips of the upper and lower guard plates are correct, and that they are in good contact with the roller surface, and that the tightness of the guard plate installation should be appropriate; excessively worn and worn out copper tips should be replaced in time;<\/p>\n\n\n\n

\u2462 When the roll is turned, the fatigue crack layer should be turned off as much as possible;<\/p>\n\n\n\n

\u2463 Turn off the cooling water of the rolls in time when parking to avoid fried lines on the rolls; ensure that the cooling water of the rolls is uniform during normal rolling;<\/p>\n\n\n\n

\u2464 When leveling and pressing into the disc or round steel, the amount of reduction should not be too large, otherwise groove marks will be pressed on the roll. In addition, under the condition of other normal conditions, the end must be adjusted before changing the roll and after leveling. Check the roll surface of the rack to see if there are any defects;<\/p>\n\n\n\n

\u2465 When installing the work roll, be sure to confirm the position of the upper support roll and the bearing box to avoid scratching and scratching the work roll;<\/p>\n\n\n\n

\u2466 Pay attention to the protection of the feed roller, free roller and pinch roller on the roller table during inspection and daily maintenance. Avoid some things such as: dripping of welding bump, damage of gas cutting, etc.;<\/p>\n\n\n\n

\u2467Guarantee the quality of new rolls, and reject or feedback the defective rolls.<\/p>\n\n\n\n

3. Processing method:<\/p>\n\n\n\n

\u2460 After the measuring worker discovers the roll damage, he should notify the operation desk in time.<\/p>\n\n\n\n

\u2461 For roll damage beyond the standard range, measures to stop rolling should be taken immediately, and the roll damage should be checked one by one according to the characteristics of the form and cycle of the roll damage, and it should be replaced immediately after detection.<\/p>","protected":false},"excerpt":{"rendered":"

Keyword\uff1aRolling process, billets, mill rolls Description\uff1a Rolling is a process in which metal bars, plates, profiles, etc. are deformed through continuous stress to obtain the required shape and size. In this process, you should pay attention to the following places to ensure the quality and performance of metal materials Strip steel (strip billet) warped head […]<\/p>","protected":false},"author":1,"featured_media":7299,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_templately_pack_id":"","_templately_imported_at":"","_templately_source":"","_templately_import_session_id":"","footnotes":""},"categories":[1],"tags":[66],"class_list":["post-7295","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-uncategorized","tag-rolling-mill-rolls"],"_links":{"self":[{"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/posts\/7295","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/comments?post=7295"}],"version-history":[{"count":2,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/posts\/7295\/revisions"}],"predecessor-version":[{"id":7302,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/posts\/7295\/revisions\/7302"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/media\/7299"}],"wp:attachment":[{"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/media?parent=7295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/categories?post=7295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lmmrolls.com\/hi\/wp-json\/wp\/v2\/tags?post=7295"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}