High speed wire technology summary: Process adjustment of finishing mill group
The process adjustment of the finishing mill group is generally only adjusted the first sortie and the finished sortie, and other sorties are not allowed to be adjusted at will, for two reasons:
1) Moving the roll gap of one of the frames will destroy the micro-tension relationship between the frames, resulting in product size fluctuations;
2) The opening of the guide roller of the rolling guide is precisely adjusted according to the sample rod. If a roll gap is enlarged, the incoming material will become larger, resulting in reduced service life of the guide roller or even damage the guide wheel and waste products; If a secondary roll gap is reduced, it will cause the incoming material to become smaller, the guide wheel clamping is unstable, and the steel pouring phenomenon will occur.
When the size of the finished product is too high and the width is too large, the first rolling mill should be adjusted first, and the finished rolling mill should be adjusted later.
The cumulative adjustment amount of the first and finished stand mill shall not exceed 0.3mm.
When it is found that the surface quality of the billet is not good, it should be stopped to check the roller ring and guide for foreign bodies.
(1) The roll gap of the finished product is larger in vertical diameter and slightly smaller in horizontal diameter;
(2) When the vertical diameter of the finished product is small and the horizontal diameter is just right, the roll gap of the finished product is enlarged;
(3) When the vertical diameter of the finished product is just and the horizontal diameter is large, the roll gap of the first set is reduced;
(4) The vertical diameter of the finished product is just, the horizontal diameter is small, and the roll gap of the first set is enlarged.
If the requirements are still not met after the above adjustment, the incoming size of the front unit should be checked, and the roll gap of the last batch of the front unit should be enlarged or reduced. The cumulative adjustment of the roll gap of the first and last rolling mill shall not exceed 0.3mm.
The main reasons for the head pile of steel in rolling are as follows:
(1) the size of the rolled piece on the previous pass is so large that the rolled piece is squeezed in the entrance cleat when it enters the next pass, resulting in a pile of steel;
(2) Due to the uneven deformation of the billet head during rolling, the low temperature of the billet head and the inclusion of the rolled pieces may cause splitting;
(3) The torsion guide is seriously worn or the torsion guide wheel bearing is burned out, causing the torsion Angle to change, causing the pile steel;
(4) The rolled elbow is made into the next channel, causing the pile of steel.
The reasons for the tail pile of steel in rolling are:
(1) The defects caused by the billet itself, such as stratification, serious bubbles, etc., are rolled to half of the fracture caused by the pile steel during the rolling process;
(2) When the speed of an intermediate mill is not set properly, the pile steel rolling state is actually generated, and the first half of the rolled piece is rolled by the front mill to maintain tension; When the end of the rolling piece leaves the front mill, the tension there is suddenly lost, which causes the rack to produce a pile of steel;
(3) Due to the sudden acceleration or deceleration of the motor of a mill, the original continuous rolling relationship is destroyed and caused by stacking steel;
(4) Due to the sudden break of the roll, or the serious damage of the first few times, resulting in changes in the rolled section and causing the pile of steel.
The reasons for stacking steel between the stands of the finishing mill group are:
(1) Guide stick steel;
(2) the guide wheel does not turn or the bearing is burned out;
(3) rolling pieces split head;
(4) the guide or roller ring is installed incorrectly;
(5) Improper roll gap setting or incoming material size does not meet the requirements;
(6) The guide is not fastened;
(7) The roller key is broken to loosen the roller sheet;
(8) The roll is broken;
(9) the rolling roller bearing is worn or broken;
(A) The reason for the waste box pile steel when spinning 5 circles, the main reasons are
1, 28 # entrance guide is not good, such as guide installation bias, opening degree is too large, guide stick iron, guide roller does not turn, etc
2, 28 # exit guide, the rolling line between the waste box is not right, the guide base is not right, etc
3, 28 # export guide, waste box excessive wear or stick iron.
When spinning between 5 and 12 turns the main reasons are:
1, the water cooling section is installed incorrectly or excessive wear.
2, there are foreign bodies in the water cooling section.
3, water cooling water, back blowing water, air nozzle often open, closed or opened too early.
When spinning about 12 turns, the main reasons are:
1. The middle guide of the pinch roller is biased.
2. Excessive wear of the trumpet core tube of the spinning machine.
3. The pinch roller is in a normally closed state.
Causes of the waste box pile steel in the end of the wire rod:
1. The speed match between finishing mill, pinch roll and spinning machine is not correct.
2, pinch roll opening set wrong.
3. The parameter setting of the pinch roller is wrong during the full pinch process, such as cylinder pressure, roll diameter, current limiting value, etc.
4, the steel is not good, such as rotten steel
(2) Determine where the steel head runs according to the number of spinning rings, and generally check the position and cause of the impact of the steel head before the position. Measures taken for scrap bin stacking steel
1, the initial installation of the waste box turning transduction slot and rolling line deviation, and later re-center the base of the waste box turning transduction slot.
2. The top cover moves up and down after the turn transduction groove pin is ground, up to 0.5-0.6mm in serious cases, and then replace the original pin with a screw.
3. The upper cover of the waste box is too light, easy to open, too heavy, and can not protect, and later the weight of the upper cover of the waste box is increased.
4. Transform the back guide of the pinch roller to increase its inclination Angle and avoid the steel head hitting the inlet pipe of the wire spinning machine.
5. The middle guide fixture of the pinch roller is biased, resulting in the middle guide and guard being biased, and the new fixture is replaced.
6, the use of the water cooling section guide groove standards: after finishing rolling, the maximum wear diameter of the specification guide groove in the water cooling section is not more than 24mm,
The maximum wear diameter of the small guide groove is not greater than 19mm, the deviation from the center line is not more than 2mm, and the swing of the guide tube is not more than 2mm.
Delimit maintenance responsibility: the responsibility for the misalignment of the rolling line at the outlet of 28 sets to the pinch roll is attributed to the production preparation, and the rolling line is required to be calibrated once a month.
Primary school day repair and parking time is school. The rolling workshop is responsible for checking whether there are steel heads, steel slag and water nozzle is active, and the water nozzle activity is borne by the preparation;
After the pile steel post-treatment, the alignment of the guide groove is undertaken by the rolling steel, and the wobble of the water nozzle conduit is resolved by the production preparation
Quality and influence of red billet
1. The size of the rolled piece on the pass is too high or too wide, which will make the rolled piece crowded in the inlet guide of the pass and blocked the pile steel. The head of the rolled piece should be observed to make a judgment.
2, the uneven deformation of the rolled head in the large amount of rolling, head low temperature or slag inclusion and other reasons cause the splitting, causing the pile of steel.
3, the last pass incoming material is too small, resulting in the gap between the rolled piece and the guide is too large, causing the head to pour steel, so that the rolled piece is blocked in the pass inlet guide and cause the pile steel.
4. The center line of the import and export guide is inconsistent with the center line of the hole, the wear of the upper and lower rollers is uneven, and the elbow caused by the gap of the transmission components is too large.
5, red blank size set improperly, can cause the roller ring fracture or fragmentation.
6, the size of the incoming material will be too full in the pass and produce ears, resulting in folding.
7, the size of the incoming material is too small will make the rolled piece swing back and forth to produce irregular ears, causing irregular folding.
8. The roughing mill takes advantage of the high temperature of the rolled piece and increases the extension of the rolled piece.
9. The pre-finishing mill group uses the middle rolled piece with good surface quality and small section tolerance to meet the requirements of the finishing mill group and ensure the reduction of waste.
10, the finishing mill group each frame material shape meets the requirements, in order to ensure the normal continuous rolling relationship (expected micro-tension rolling effect).
11, the temperature of the red billet affects the size of the deformation resistance and thus affects the size of the motor load.
12, the lower temperature of the rolling piece will lead to the increase of the mill bounce and affect the metal second flow, resulting in a slight stacking of steel phenomenon.
13, the low temperature of the rolled head will increase the head width and pile steel.
14. The high temperature of the rolling piece will make it too soft in the finishing mill group, and will also make the secondary oxidation serious, causing the oxide sheet to fall off and block the guide reactor steel.
15, the uneven temperature of rolled parts will cause tension fluctuations, which will affect the accuracy of the finished product.
The problems of spinning circle falling from left to right, the size of spinning circle is different and the spinning circle is not round affect the production.
The analysis holds that:
1. The reason why the spit ring falls left and right is that when the coil is spit down at the outlet of the spit tube, there is a coil tangential direction speed. Technically, the spinning coil should fall smoothly and evenly by adjusting the speed lead value of the spinning machine and the pinch roller.
2, the size of the spinning circle is different. Due to the continuous wear of the wall of the spinning tube, the dynamic balance of the spinning machine is destroyed, and the spinning process may be blocked due to wear, so the wear resistance requirements of the spinning tube should be improved, and the rotational speed of the spinning machine should be reduced. Improper installation of the spinning tube, high temperature spinning, deformation and positioning of the spinning tube will also cause large and small rings, which should be strictly installed;
On the other hand, the wear of the related equipment will also cause the size of the ring. The wall thickness of the wire tube, the bending pipe at the outlet of the pinch roll, the guide groove between the two-module mill and the pinch roll, and the wear of the control cold water pipe of the control cold water tank should be checked and adjusted in time. In addition, improper electrical automation control and improper rolling tension adjustment will also appear small and small rings, and relevant necessary measures should be taken.
3. The spit circle is not round. The spinning circle is not round because the spinning tube is not replaced or used after the rolling line is changed, which causes the destruction of the dynamic balance after the spinning tube is worn, and the new spinning tube is not tested after the replacement of the action balance, which should be checked regularly and the spinning dynamic balance test should be carried out during installation.
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