Method for eliminating machine set punch marks through machine set start and stop
阅读说明：本技术 一种通过机组起停车消除机组硌印的方法 (Method for eliminating machine set punch marks through machine set start and stop ) 是由 孙帅 王汝飞 王洋 王锦波 杨增荣 江波 刘成群 李晓 许铭 王永新 刘新宇 于 2021-08-23 设计创作，主要内容包括：本发明公开了一种通过机组起停车消除机组硌印的方法,当机组发现炉内硌印后,降速到最低工艺速,将炉区各段张力降低30-50％,再将带温降低到满足最低退火温度；等带温降低到最低退火温度后加大退火炉各段张力；炉区张力稳定后再提升炉速,直接按炉区快停按钮；带钢速度为0,将炉区张力卸掉后再重新建张,张力稳定后炉区直接升速,往复几次后炉内硌印消除；当机组发现平整机硌印后,首先提升平整机前后防皱辊高度,增加延伸率0.1％,平整机速度在30-550m/min之间往复升降速或急速启停车,消除轧辊表面异物；本发明在不停机开炉、平整机不换辊的情况下消除炉内炉辊及平整机轧辊硌印,缩短处理缺陷时间,减少降级品发生量。(The invention discloses a method for eliminating punch marks of a machine set by starting and stopping the machine set, when the machine set finds punch marks in a furnace, the speed is reduced to the lowest process speed, the tension of each section of the furnace area is reduced by 30-50%, and then the strip temperature is reduced to meet the lowest annealing temperature; increasing the tension of each section of the annealing furnace after the strip temperature is reduced to the lowest annealing temperature; after the tension of the furnace area is stable, the furnace speed is increased, and a furnace area quick-stop button is directly pressed; the strip steel speed is 0, the tension in the furnace area is relieved and then the new tension is built, the furnace area is directly accelerated after the tension is stable, and the punch marks in the furnace are eliminated after the process of reciprocating for several times; after a machine set finds that the planisher is embossed, firstly, the heights of front and rear crease-resistant rollers of the planisher are increased, the elongation is increased by 0.1%, the speed of the planisher is increased and decreased in a reciprocating mode between 30 and 550m/min or the planisher is started and stopped rapidly, and foreign matters on the surfaces of the rollers are eliminated; the invention eliminates the punch marks of the furnace roller and the roller of the temper mill under the conditions of blowing in the furnace without stopping the machine and not changing the roller of the temper mill, shortens the defect processing time and reduces the generation amount of degraded products.)
1. A method for eliminating machine set punch marks through machine set start and stop is characterized by comprising the following steps:
1) after the machine set finds punch marks in the annealing furnace, the furnace speed of the machine set is reduced to the lowest process speed, and meanwhile, the tension of each section of the annealing furnace area is reduced by 30-50%;
2) then reducing the strip temperature to meet the minimum annealing temperature;
3) after the temperature of the annealing band is reduced to the lowest annealing temperature, the tension of each section of the annealing furnace is increased, particularly the tension of a defect generation area is increased to 130-150% of the original tension;
4) after the tension of the furnace area is stable, the furnace speed is increased to 100-130m/min, and after the speed is stable, a furnace area quick-stop button is directly pressed to quickly stop the annealing furnace;
5) after the speed of the strip steel in the annealing furnace is 0, the tension in the furnace area is removed, the tension is rebuilt after the tension is completely removed, the tension is increased by 30-50% on the basis of the original tension, the furnace area is directly accelerated to 100 plus 130m/min after the tension is stable, and the punch marks in the furnace can be eliminated after the process is repeated for several times;
6) after a machine set finds that the planisher is embossed, firstly, the height of front and rear crease-resistant rollers of the planisher is increased by 30-50mm, the elongation is increased by 0.1%, and the front and rear tension of the planisher is increased by 20-30%;
7) the speed of the leveler is increased or decreased in a reciprocating way or stopped rapidly between 30 and 550m/min, and foreign matters on the surface of the roller can be eliminated.
2. The method for eliminating the machine set punch marks through the start and stop of the machine set according to claim 1, wherein the tension of the annealing furnace area in the steps 1), 3) and 5) is controlled to be too high in furnace tension, which causes hot buckling of strip steel, too low in furnace tension causes deviation at the inlet of the annealing furnace, and too high in tension difference of each section in the furnace causes overload of a furnace roller motor; the tension measuring points in the furnace are all at the bottom roller of the furnace and are the lowest tension in the furnace, the tension displayed on a computer system is the lowest tension in the area, the highest tension in the furnace is calculated and the gravity of the strip steel in the furnace is added,
namely: t is tmax+BHSρ+BHRαρ＜Rp0.2×H
tmax＜Rp0.2×H-HMρ-HRαρ。
3. Method for eliminating crew punch marks by crew start and stop according to claim 2, characterized in that t in the formulamaxThe maximum unit tension, B the strip width, H the strip thickness, and p the material density 7850kg/m3Alpha is the taper angle of the single taper roller, M is the length between the tangent lines of the upper and lower furnace rollers, Rp0.2The maximum tension of the strip steel in the formula is not more than the yield strength of the material, and the minimum tension of the strip steel is not more than 50% of the secondary original tension value.
Technical Field
The invention relates to the technical field of metallurgy, in particular to a method for eliminating punch marks of a unit through start and stop of the unit.
Background
The cold rolling continuous annealing unit consists of a series of large single equipment, and the strip steel is sequentially processed by the processing equipment to form a final cold rolling finished product. Different quality defects can occur in the process treatment process of each large-scale device, particularly, the punch mark defects of an annealing furnace and a flattening machine are more, and the defects are difficult to treat due to the working condition, so that the defects become a difficult problem in the high-quality stable production process of a cold rolling continuous annealing unit. Through the skillful grasp of the production process and the continuous exploration and breakthrough of the ultimate capacity of equipment, a method for changing the friction force between the strip steel and the roller by adjusting the tension and the running speed of a unit is gradually explored, so that the punch-through mark is eliminated. At present, a conventional method is to equip a scraper on a unit tension roller, and the scraper is used for scraping the roller, so that foreign matters on the roller can be eliminated. The defects are that the scraper is easy to damage the roller, the service life of the roller is shortened, and meanwhile, the scraper needs to be replaced periodically, so that the cost is increased. And the roller of the temper mill and the roller of the annealing furnace cannot be provided with scrapers due to the restriction of working conditions and the restriction of high temperature in the annealing furnace, and foreign matters can be eliminated only by replacing the roller or adjusting the speed difference of the roller. The method has the advantages of poor effect of eliminating foreign matters with serious roller surface adhesion, long treatment time and more degraded products. Aiming at the limitation of the existing means, a method for eliminating the punch marks of the unit by starting and stopping the unit needs to be designed.
Patent CN 101660039a "a method for eliminating cold rolled steel sheet rough annealing mark" utilizes a plurality of annealing furnace roller sets composed of different roller diameters in a continuous annealing furnace and a plurality of steel sheet automatic deviation rectifying control modules corresponding to each annealing furnace roller set, controls the furnace roller automatic deviation rectifying control modules through manual braking, adjusts the displacement required by the steel sheet, and removes the foreign matters adhered on the surface of the furnace roller by using the edge of the steel sheet. The method is obviously different from the method for eliminating the punch marks of the strip steel in the annealing furnace by adjusting the temperature in the furnace, the tension and the speed of the strip steel, and the method does not contain how to eliminate the punch marks caused by the temper mill.
Disclosure of Invention
The invention aims to provide a method for eliminating punch marks of a unit through start and stop of the unit, aiming at solving the problems in the prior art.
The technical scheme adopted by the invention for solving the technical problems is as follows: a method for eliminating unit punch marks through unit start and stop comprises the following steps:
1) after the machine set finds punch marks in the annealing furnace, the furnace speed of the machine set is reduced to the lowest process speed, and meanwhile, the tension of each section of the annealing furnace area is reduced by 30-50%;
2) then reducing the strip temperature to meet the minimum annealing temperature;
3) after the temperature of the annealing band is reduced to the lowest annealing temperature, the tension of each section of the annealing furnace is increased, particularly the tension of a defect generation area is increased to 130-150% of the original tension;
4) after the tension of the furnace area is stable, the furnace speed is increased to 100-130m/min, and after the speed is stable, a furnace area quick-stop button is directly pressed to quickly stop the annealing furnace;
5) after the speed of the strip steel in the annealing furnace is 0, the tension in the furnace area is removed, the tension is rebuilt after the tension is completely removed, the tension is increased by 30-50% on the basis of the original tension, the furnace area is directly accelerated to 100 plus 130m/min after the tension is stable, and the punch marks in the furnace can be eliminated after the process is repeated for several times;
6) after a machine set finds that the planisher is embossed, firstly, the height of front and rear crease-resistant rollers of the planisher is increased by 30-50mm, the elongation is increased by 0.1%, and the front and rear tension of the planisher is increased by 20-30%;
7) the speed of the leveler is increased or decreased in a reciprocating way or stopped rapidly between 30 and 550m/min, and foreign matters on the surface of the roller can be eliminated.
Specifically, the tension of the annealing furnace zone in the steps 1), 3) and 5) is controlled in such a way that the excessive tension in the furnace can cause the hot buckling of the strip steel, the too low tension in the furnace can cause the deviation at the inlet of the annealing furnace, and the excessive tension difference in each section in the furnace can cause the overload of a furnace roller motor; the tension measuring points in the furnace are all at the bottom roller of the furnace and are the lowest tension in the furnace, the tension displayed on a computer system is the lowest tension in the area, the highest tension in the furnace is calculated and the gravity of the strip steel in the furnace is added,
namely: t is tmax+BHSρ+BHRαρ＜Rp0.2×H
tmax＜Rp0.2×H-HMρ-HRαρ。
Specifically, t in the formulamaxThe maximum unit tension, B the strip width, H the strip thickness, and p the material density 7850kg/m3Alpha is the taper angle of the single taper roller, M is the length between the tangent lines of the upper and lower furnace rollers, Rp0.2The maximum tension of the strip steel in the formula is not more than the yield strength of the material, and the minimum tension of the strip steel is not more than 50% of the secondary original tension value.
The invention has the following beneficial effects:
the method for eliminating the press marks of the unit through the start and stop of the unit, which is designed by the invention, can efficiently and quickly eliminate the press marks of the furnace roller and the roller of the temper mill without stopping the furnace and changing the roller of the temper mill, shorten the treatment defect time, reduce the generation amount of degraded products and reduce the economic loss of enterprises.
Detailed Description
The technical scheme in the embodiment of the invention is clearly and completely further detailed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
A method for eliminating punch marks of a machine set by starting and stopping the machine set is characterized in that after the machine set finds punch marks in an annealing furnace, the speed must be reduced to the lowest process speed (see table 1) in order to reduce the generation amount of defective products, thermal buckling is not generated after the speed is greatly reduced in a furnace area, meanwhile, the tension of each section of the furnace area is reduced by 30-50% (the original tension is shown in table 2), and then the belt temperature is reduced to meet the lowest annealing temperature (the original belt temperature is shown in table 3). After the constant band temperature is reduced to the minimum annealing temperature, the tension of each section of the annealing furnace is increased, particularly the tension of the suspected defect generation area is increased to 130-150% of the original tension. After the tension of the furnace area is stable, the furnace speed is increased to 100-130m/min, and after the speed is stable, the furnace area quick stop button is directly pressed to quickly stop the annealing furnace. And (3) after the speed of the strip steel in the annealing furnace is 0, relieving the tension of the furnace area, reestablishing the tension after the tension is completely relieved, increasing the tension by 30-50 percent on the basis of the original tension, directly increasing the speed of the furnace area to 100 plus material 130m/min after the tension is stable, and eliminating the punch marks in the furnace after repeating for a plurality of times. The operation is mainly to improve the friction force between the strip steel and the furnace roller by increasing the strip steel tension in the furnace, and the roller and the strip steel generate relative slippage after the furnace is started and stopped quickly, so as to rub off foreign matters on the surface of the roller, so that the method can treat the punch marks in the furnace by adjusting the furnace temperature, the furnace speed and the strip steel tension under the condition of non-stop furnace opening.
After the press marks of the planisher are found, the height of front and rear crease-resistant rollers of the planisher is firstly increased by 30-50mm (the height of an original crease-resistant roller is shown in a table 4), the elongation is increased by 0.1%, and the front and rear tension of the planisher is increased by 20-30% (the tension of the original planisher is shown in a table 5). The speed of the leveler is increased or decreased in a reciprocating way or stopped rapidly between 30 and 550m/min, and foreign matters on the surface of the roller can be eliminated. The operation is to eliminate the foreign matter on the roller surface by increasing the front and back tension and rolling force of the planisher and rolling wrap angle and using the rapid starting, stopping and speed increasing to generate larger friction on the roller and the surface of the strip steel, which is a method for eliminating the planishing mark by adjusting the rolling parameters of the planisher under the condition that the roller of the planisher is not changed and the speed of a furnace zone is not reduced.
The key point of the tension control of the furnace area is that the thermal buckling of the strip steel can be caused by the overlarge tension in the furnace, and the deviation can be generated at the inlet of the annealing furnace when the tension in the furnace is too small. And the excessive tension difference of each section in the furnace can cause the overload of a furnace roller motor. The tension measuring points in the furnace are all at the bottom roller of the furnace and are the points with the lowest tension in the furnace, so the tension seen on a computer screen is the lowest tension in the area, and if the highest tension in the furnace is calculated and the gravity of the strip steel in the furnace is added,
namely: t is tmax+BHSρ+BHRαρ＜Rp0.2×H
tmax＜Rp0.2×H-HMρ-HRαρ。
T in the formulamaxIs the maximum unit tension;
b is the width of the strip steel;
h is the thickness of the strip steel;
rho is the material density 7850kg/m3；
Alpha is the taper angle of the single taper roller;
m is the length between the tangent lines of the upper furnace roller and the lower furnace roller;
Rp0.2is the yield strength of the material;
the maximum tension of the strip steel in the formula is not more than the yield strength of the material, and the minimum tension of the strip steel is not more than 50% of the secondary original tension value.
The key point of the furnace zone temperature control is that the yield strength of the strip steel is too low due to too high furnace temperature, the furnace roller convexity is too large, and the buckling of the strip steel in the heating zone is easily caused after the two conditions are superposed. If the furnace temperature is too low, the recrystallization annealing of the strip steel can not be finished, and defective products are produced.
The key point of the speed control in the furnace is that the roll shape of the heating area is degraded and then the deviation occurs when the speed is too high, and the strip steel annealing time is too long and the performance of the strip steel is affected or the buckling occurs when the speed is too low.
If the height of the crease-resist roller of the temper mill is too low, the rolling wrap angle is too small, the contact surface of the strip steel and the roller is small, and the function of increasing friction force cannot be achieved. If the height of the anti-wrinkling roller is too high, the strip steel is easy to scratch the waterproof baffle to cause strip breakage.
The elongation is increased to increase the rolling force, so that the friction between the strip steel and the roller is increased.
The front and back tension of the temper mill is increased to increase the friction between the strip steel and the roller.
The present invention will be described in further detail with reference to specific examples.
Example 1
Producing steel grades: DC04
Specification: 1 x 1300 mm.
When a machine set finds punch marks in the furnace, the speed must be reduced to the lowest process speed of 50m/min in order to reduce the generation amount of defective products, and in order to ensure that thermal buckling does not occur after the speed is greatly reduced in a furnace zone, the tension of a heating section in the furnace zone is reduced to 5.4KN from 7.8KN by operating personnel in the furnace zone, and the temperature of a strip is reduced to 800 ℃ to meet the lowest annealing temperature. And increasing the tension of the hot section of the annealing furnace to 10.2KN after the strip temperature is reduced to the minimum annealing temperature of 800 ℃. And after the furnace area tension is stable, the furnace speed is increased to 150m/min, and after the furnace speed is stable, a furnace area quick stop button is directly pressed to quickly stop the annealing furnace. And (4) removing the tension of the furnace zone after the speed of the furnace zone is 0, and re-building the furnace zone to 10.2KN after the tension is completely removed. After the tension is stable, the furnace area directly rises to 150m/min, and after 4 times of reciprocating, the punch mark elimination is observed at the outlet of the furnace area.
Example 2
Producing steel grades: DC01
Specification: 1 x 1100mm
When a machine set finds punch marks in the furnace, the speed must be reduced to the lowest process speed of 50m/min in order to reduce the generation amount of defective products, and in order to ensure that thermal buckling does not occur after the speed is greatly reduced in a furnace zone, the tension of a heating section in the furnace zone is reduced to 5.2KN from 7.7KN by operating personnel in the furnace zone, and the temperature of a strip is reduced to 760 ℃ to meet the lowest annealing temperature. And increasing the tension of each section of the annealing furnace to 9.8KN after the temperature of the strip is reduced to the lowest annealing temperature of 760 ℃. And after the furnace area tension is stable, the furnace speed is increased to 150m/min, and after the furnace speed is stable, a furnace area quick stop button is directly pressed to quickly stop the annealing furnace. And (4) removing the tension of the furnace zone after the speed of the furnace zone is 0, and re-building the furnace zone to 9.8KN after the tension is completely removed. After the tension is stable, the furnace area directly rises to 150m/min, and after 3 times of reciprocating, the punch marks are observed and eliminated at the outlet of the furnace area.
Example 3
Producing steel grades: DC03
Specification: 1.2 x 1300mm
After the planisher punch mark is found in the machine set, the heights of the front and rear crease-resisting rollers of the planisher are firstly raised to 160mm and 170mm from 130mm and 140mm, the elongation is increased to 0.6% from 0.5%, and the front and rear tension of the planisher is increased to 84.5KN from 70.5 KN. The speed of the planisher is increased and decreased in a reciprocating mode between 30mm and 550mm, the planisher is rapidly started and stopped, and after the operation is repeated for more than 5 times, the punch mark defect disappears when the planisher is observed at the outlet of the planisher.
Example 4
Producing steel grades: DC01
Specification: 0.8 x 1600mm
After the set finds the punch mark of the planisher, the heights of the front and rear crease-resisting rollers of the planisher are firstly raised to 180mm and 210mm from 150mm and 180mm, the elongation is increased to 1.1% from 1.0%, and the front and rear tension of the planisher is increased to 75KN from 61.5 KN. The speed of the planisher is increased and decreased in a reciprocating mode between 30 and 550m/min and the planisher is rapidly started and stopped, and the abrasion mark defects are observed to disappear at the outlet of the planisher after the planisher is repeatedly operated for more than 6 times.
Table 1: minimum speed m/min in furnace zone
Table 2: original tension N/mm of furnace area2
Table 3: minimum annealing temperature of different steel grades
TABLE 4 original crease roll height
Thickness of strip steel (mm)
Inlet crease-resist roller height (mm)
Outlet crease-resist roller height (mm)
0.4
150
230
0.5
150
225
0.6
150
220
0.7
150
190
0.8
150
180
0.9
150
170
1
150
160
1.1
140
150
1.2
130
140
1.3
120
130
1.4
110
120
1.5
100
110
1.6
90
90
1.7
80
80
1.8
70
70
1.9
60
60
2
50
50
2.1
40
40
2.2
30
30
2.3
30
30
2.4
30
30
2.5
30
30
TABLE 5 original tension at inlet and outlet of temper mill
Thickness (mm)
Inlet of planisher (N/mm2)
Exit of temper mill (N/mm2)
[0.3～0.6]
50
50
(0.6～0.8]
48
48
(0.8～1.0]
46
46
(1.0～1.2]
45
45
(1.2～1.5]
43
43
(1.5～1.8]
40
40
(1.8～2.2]
38
38
(2.2～2.5]
35
35
The present invention is not limited to the above embodiments, and any structural changes made under the teaching of the present invention shall fall within the scope of the present invention, which is similar or similar to the technical solutions of the present invention.
The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：不锈钢混酸酸洗污泥的回收利用方法及系统