CN113787096A - Rolling mill screw-down control method during start-up of double-roller thin strip casting and rolling process - Google Patents

Abstract

A rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line; adjusting the roll gap of the working roll of the rolling mill, then carrying out pressure test, continuously adjusting the inclination of the working roll and then carrying out pressure test again according to the deviation and the plate shape of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill until the plate shape, the thickness and the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill meet the requirements; and recording the rolling parameters at the moment as normal production parameters for subsequent continuous production.

Description

Rolling mill screw-down control method during start-up of double-roller thin strip casting and rolling process

Technical Field

The invention relates to a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process, belonging to the technical field of metallurgical steel rolling equipment.

Background

The common thin strip production process flow is continuous casting of a thick intermediate slab → reheating and heat preservation of a casting blank → rough rolling → finish rolling → coiling, and if a steel strip with the thickness of less than 2.5mm (inclusive) is to be produced, the whole production process has high difficulty, long process flow, high energy consumption, more unit equipment and high capital construction cost, so that the production cost is high and the instability is increased.

The CSP thin slab continuous casting and rolling process flow is as follows: continuous casting thin slab → casting blank heat preservation soaking → hot continuous rolling → coiling. Compared with the technique for producing the thin strip by the thick intermediate plate blank, the CSP technique greatly simplifies the production procedures and shortens the production period; the equipment investment is correspondingly reduced, the product cost is obviously reduced, and the method is a low-carbon and environment-friendly hot-rolled thin strip production process.

The twin-roll thin strip casting process is a main form of the thin strip casting process, but has not been widely popularized previously due to the limitation of production conditions. The twin-roll thin strip casting and rolling technology is a continuous process integrating casting and rolling. The method is characterized in that liquid metal is used as a raw material, 2 casting rolls with opposite rotating directions are used as crystallizers, thin strips with the thickness of 1-5mm are directly cast by liquid molten steel, and the thin strips are rolled by a single-stand rolling mill and then coiled. The process simplifies a series of conventional procedures such as continuous casting, rough rolling, hot continuous rolling and related heating, end cutting and the like, and greatly shortens the production flow of the thin strip steel. Therefore, compared with the traditional mode, the thin strip steel produced by adopting the twin-roll casting and rolling mode greatly saves energy, reduces metal consumption and equipment investment cost and greatly reduces production cost. The production flow of the twin-roll thin strip casting and rolling comprises the following steps: molten steel in a large ladle is directly poured into a molten pool enclosed by two crystallization rollers which rotate relatively and can be cooled rapidly and a side sealing device through a large ladle long nozzle, a tundish and a flow distribution device, because the cooling intensity is high, the cooling speed is high, the molten steel is solidified on the circumferential surface of the rotation of the crystallization rollers to form a solidified shell and gradually grow, a steel strip with the thickness of 1-5mm is formed at the minimum position of the gap between the two crystallization rollers, the steel strip is sent into a rolling mill through a guide plate guide pinch roller to be rolled into a thin strip with the thickness of 0.7-2.5mm, then is cooled through a cooling device, is cut by a flying shear device, and is finally sent into a coiling machine to be coiled.

One of the existing double-roll thin strip casting and rolling process patents mainly focuses on smelting objects, for example, the invention patent CN200910010472 of the northeast university focuses on a high-phosphorus weather-resistant steel casting and rolling thin strip with negative phosphorus segregation on the surface and a preparation method thereof, and the invention patent CN201110237025 of the northeast university focuses on a preparation method of a tin-containing ferrite stainless steel thin strip with reverse tin segregation. The invention patent CN201210317194 of Baoshan steel focuses on a boron-containing weather-resistant thin strip steel and a manufacturing method thereof, and the invention patent CN201710288312 of liquor spring steel focuses on a production process of ultra-pure ferrite stainless steel double-roll strip casting and rolling.

Another type of equipment is concerned with the direction of twin-roll strip casting and rolling, for example, patent CN200710185377 of the university of yanshan is concerned with a vibrating twin-roll strip casting and rolling machine, which moves up the position of the solidification end point, changes the shape of the solidification liquid cavity, distributes alloy components uniformly, reduces segregation, refines grains, and can reduce the product defects of cracks, delamination and the like. The casting and rolling speed, the product quality and the production efficiency are improved. The invention patent CN200610134351 of Liaoning science and technology university focuses on a controlled rolling method and device for twin-roll continuous casting of magnesium alloy sheets, a hot strip blank is produced by twin-roll casting, and then line control temperature and deformation rolling are immediately followed to produce the magnesium alloy sheet with good forming and secondary processing capability. The invention patent CN201010153916 of Shanxi Yingguang Huasheng magnesium industry focuses on magnesium alloy wide plate casting and rolling equipment, and the invention patent CN202010559089 of the university of China and south focuses on a device and a method for simulating a double-roller thin-strip continuous casting process.

Therefore, in the actual production process, the relationship between the twin-roll casting process and the type of the smelting product is large. In addition, much emphasis is placed on the modification of the plant itself, with less attention paid to the control of the rolling production. The invention has found that when the steel plate for the automobile is produced, because the steel plate is rolled by a single frame and the thickness of the steel strip is thin, the phenomena of central line deviation, rolling erosion and the like of the steel strip are easy to occur after the rolling mill is pressed down, and the steel clamping can be caused to stop production in serious cases, thereby causing great economic loss.

Disclosure of Invention

The invention aims to provide a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process, in particular to a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process for an automobile steel plate, which can effectively avoid the phenomena of strip steel deflection, rolling breakage and the like in the beginning of the automobile steel plate.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is arranged on a twin-roll thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively arranged at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line.

Further, the control method is characterized in that: and adjusting the roll gap of the working roll of the rolling mill, testing pressure, continuously adjusting the inclination of the working roll according to the deviation and the plate shape of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill, and testing pressure again until the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill is within +/-10 mm and the wedge shape is within +/-100 mu m. And recording the rolling parameters at the moment as normal production parameters for subsequent continuous production.

The steel plate for the automobile comprises the following components in percentage by weight: 0.01-0.02%, Si: 0.1-0.15%, Mn: 1.4-1.6%, Cr: 0.1-0.4%, Nb: 0.04-0.08%, V: 0.02 to 0.06%, Ti: 0.02 to 0.06%, Cu: 0.02 to 0.06%, Al: less than or equal to 0.003 percent, P: less than or equal to 0.02 percent, S: less than or equal to 0.005 percent, and the balance of Fe and inevitable impurity elements.

Casting and rolling a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, and the roller speed of a crystallizer is 30-40 m/min; in the casting and rolling process, the casting temperature of the molten steel is 1540-1600 ℃, the molten steel is injected into a double-roller casting and rolling machine through a submerged nozzle, the roll gap of a casting and rolling roll is adjustable between 1.5 mm and 40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-;

a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line; the method comprises the following specific steps:

(1) c in percentage by weight: 0.01-0.02%, Si: 0.1-0.15%, Mn: 1.4-1.6%, Cr: 0.1-0.4%, Nb: 0.04-0.08%, V: 0.02 to 0.06%, Ti: 0.02 to 0.06%, Cu: 0.02 to 0.06%, Al: less than or equal to 0.003 percent, P: less than or equal to 0.02 percent, S: less than or equal to 0.005 percent, and the balance of Fe and inevitable impurity elements to prepare molten steel;

(2) casting and rolling the qualified smelted molten steel by adopting a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, the roller speed of a crystallizer is 30-40 m/min, and the thickness of strip steel is 1.9-2.5 mm; in the casting and rolling process, the casting temperature of the molten steel is 1500-1580 ℃, the molten steel is injected into a double-roller casting and rolling machine through an immersion nozzle, the roll gap of a casting roller is adjustable between 1.5 mm and 40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-;

(3) the roll gap of the initial rolling mill is parallel to the horizontal plane; the rolling mill is pressed down until the roll gap is 1.7-2.2mm, the strip steel enters a 2# coiling machine after passing through a flying shear cutting head, and the condition is detected according to a rolling mill outlet multifunctional instrument;

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-2 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of the roll gap of the rolling mill to +/-3 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-1.5 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out the 2 nd trial rolling, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-2.5 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

It should be clear to one skilled in the art that a twin roll strip casting line is a continuous process where casting and rolling are integrated. The method is characterized in that liquid metal is used as a raw material, 2 casting rolls with opposite rotating directions are used as crystallizers, thin strips with the thickness of 1-5mm are directly cast by liquid molten steel, and the thin strips are rolled by a single-stand rolling mill and then coiled.

The invention has the beneficial effects that: the invention can effectively avoid the accidents of steel scrap, water stop and the like caused by the pressing down of the rolling mill during the initial rolling, improve the production efficiency and save the cost.

Drawings

FIG. 1 is a schematic diagram of a twin roll strip casting line layout;

1-steel ladle; 2, pouring a tundish; 3, distributing the bags; 4-a crystallizer; 5, pinch rolls; 6-rolling mill entrance multifunctional instrument; 7, rolling; 8-rolling mill outlet multifunctional instrument; 9-pinch roll before the flying shear; 10, flying shears; 11-pinch roll behind the flying shear; 12-1 # pinch roll; 13-1 # recoiling machine; 14-2 # pinch roll; 15-2 # coiler; 16-waste hopper.

Detailed description of the preferred embodiments

The application of the invention is further illustrated by way of example in the following with reference to the accompanying drawings.

Example 1:

a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line;

(1) c in percentage by weight: 0.01-0.02%, Si: 0.1-0.15%, Mn: 1.4-1.6%, Cr: 0.1-0.4%, Nb: 0.04-0.08%, V: 0.02 to 0.06%, Ti: 0.02 to 0.06%, Cu: 0.02 to 0.06%, Al: less than or equal to 0.003 percent, P: less than or equal to 0.02 percent, S: less than or equal to 0.005 percent, and the balance of Fe and inevitable impurity elements to prepare molten steel;

(2) casting and rolling the qualified smelted molten steel by adopting a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, the roller speed of a crystallizer is 30m/min, and the thickness of strip steel is 2.3 mm; in the casting and rolling process, the casting temperature of the molten steel is 1500-1580 ℃, the molten steel is injected into a double-roller casting and rolling machine through an immersion nozzle, the roll gap of a casting roller is adjustable between 1.5 mm and 40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-;

(3) the roll gap of the initial rolling mill is parallel to the horizontal plane; the rolling mill is pressed down until the roll gap is 2.1mm, the strip steel enters a 2# coiling machine after passing through a flying shear cutting head, and the detection condition is detected according to a rolling mill outlet multifunctional instrument;

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-2 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of the roll gap of the rolling mill to +/-3 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-1.5 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out the 2 nd trial rolling, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-2.5 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Example 2:

a rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line;

(1) c in percentage by weight: 0.01-0.02%, Si: 0.1-0.15%, Mn: 1.4-1.6%, Cr: 0.1-0.4%, Nb: 0.04-0.08%, V: 0.02 to 0.06%, Ti: 0.02 to 0.06%, Cu: 0.02 to 0.06%, Al: less than or equal to 0.003 percent, P: less than or equal to 0.02 percent, S: less than or equal to 0.005 percent, and the balance of Fe and inevitable impurity elements to prepare molten steel;

(2) casting and rolling the qualified smelted molten steel by adopting a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, the roller speed of a crystallizer is 35m/min, and the thickness of strip steel is 2.0 mm; in the casting and rolling process, the casting temperature of the molten steel is 1500-1580 ℃, the molten steel is injected into a double-roller casting and rolling machine through an immersion nozzle, the roll gap of a casting roller is adjustable between 1.5 mm and 40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-;

(3) the roll gap of the initial rolling mill is parallel to the horizontal plane; the rolling mill is pressed down until the roll gap is 1.9mm, the strip steel enters a 2# coiling machine after passing through a flying shear cutting head, and the detection condition is detected according to a rolling mill outlet multifunctional instrument;

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-2 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of the roll gap of the rolling mill to +/-3 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-1.5 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out the 2 nd trial rolling, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-2.5 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Example 3

A rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line;

(1) c in percentage by weight: 0.01-0.02%, Si: 0.1-0.15%, Mn: 1.4-1.6%, Cr: 0.1-0.4%, Nb: 0.04-0.08%, V: 0.02 to 0.06%, Ti: 0.02 to 0.06%, Cu: 0.02 to 0.06%, Al: less than or equal to 0.003 percent, P: less than or equal to 0.02 percent, S: less than or equal to 0.005 percent, and the balance of Fe and inevitable impurity elements to prepare molten steel;

(2) casting and rolling the qualified smelted molten steel by adopting a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, the roller speed of a crystallizer is 40m/min, and the thickness of strip steel is 1.9 mm; in the casting and rolling process, the casting temperature of the molten steel is 1500-1580 ℃, the molten steel is injected into a double-roller casting and rolling machine through an immersion nozzle, the roll gap of a casting roller is adjustable between 1.5 mm and 40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-;

(3) the roll gap of the initial rolling mill is parallel to the horizontal plane; the rolling mill is pressed down until the roll gap is 1.8mm, the strip steel enters a 2# coiling machine after passing through a flying shear cutting head, and the detection condition is detected according to a rolling mill outlet multifunctional instrument;

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-2 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of the roll gap of the rolling mill to +/-3 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-1.5 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out the 2 nd trial rolling, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-2.5 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Comparative example 1

The only difference from example 1 is:

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-4 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-4 + (N-2) DEG relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-3 degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-4 + (N-2) DEG relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

For the rolling mill reduction control method, the adjustment range of the single roll gap of the rolling mill is large, and the operation difficulty is large.

Comparative example 2

The only difference from example 1 is:

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-1 DEG relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-8), adjusting the inclination degree of a roll gap of the rolling mill to +/-1.5 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

Thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-1 DEG relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-8), adjusting the inclination degree of the roll gap of the rolling mill to +/-2 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

According to the rolling mill reduction control method, although the adjustment range of a single roll gap of the rolling mill is small, the number of pressure tests is large, and stable product quality can be obtained only in the 6 th to 8 th pressure tests.

Claims (3)

1. A rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line; adjusting the roll gap of the working roll of the rolling mill, then carrying out pressure test, continuously adjusting the inclination of the working roll and then carrying out pressure test again according to the deviation and the plate shape of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill until the plate shape, the thickness and the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill meet the requirements; and recording the rolling parameters at the moment as normal production parameters for subsequent continuous production.

2. The rolling mill reduction control method at the beginning of the twin-roll thin strip casting process according to claim 2, characterized in that: casting and rolling a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, and the roller speed of a crystallizer is 30-40 m/min; in the casting and rolling process, the casting temperature of the molten steel is 1540-1600 ℃, the molten steel is injected into a double-roller casting and rolling machine through a submerged nozzle, the roll gap of a casting and rolling roll is adjustable within 1.5-40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-.

3. A rolling mill screw-down control method in the beginning of a double-roller thin strip casting and rolling process is characterized in that: a primary rolling mill is installed on a double-roller thin strip casting and rolling production line, and multifunctional instrument detection devices are respectively installed at the inlet and the outlet of the rolling mill to detect the strip shape, the thickness and the strip center line; the method comprises the following specific steps:

(1) c in percentage by weight: 0.01-0.02%, Si: 0.1-0.15%, Mn: 1.4-1.6%, Cr: 0.1-0.4%, Nb: 0.04-0.08%, V: 0.02 to 0.06%, Ti: 0.02 to 0.06%, Cu: 0.02 to 0.06%, Al: less than or equal to 0.003 percent, P: less than or equal to 0.02 percent, S: less than or equal to 0.005 percent, and the balance of Fe and inevitable impurity elements to prepare molten steel;

(2) casting and rolling the qualified smelted molten steel by adopting a double-roller thin strip, wherein the diameter of a casting roller is 500-1000 mm, the roller speed of a crystallizer is 30-40 m/min, and the thickness of strip steel is 1.9-2.5 mm; in the casting and rolling process, the casting temperature of the molten steel is 1500-1580 ℃, the molten steel is injected into a double-roller casting and rolling machine through an immersion nozzle, the roll gap of a casting roller is adjustable between 1.5 mm and 40.0mm, inert gas is adopted for protection in the flowing process of the molten steel, and the cooling rate is 500-;

(3) the roll gap of the initial rolling mill is parallel to the horizontal plane; the rolling mill is pressed down until the roll gap is 1.7-2.2mm, the strip steel enters a 2# coiling machine after passing through a flying shear cutting head, and the condition is detected according to a rolling mill outlet multifunctional instrument;

(4) the detection condition takes the deviation of the central line of the strip steel detected by the multifunctional instrument at the outlet of the rolling mill to be within +/-10 mm and the wedge shape to be within +/-100 mu m as the standard of well controlled pressing during initial rolling;

firstly, if the strip steel plate shape is good when the strip steel is taken out of the rolling mill for the first time, namely the offset of a central line and the size of a wedge is in a standard range, the roll gap of the rolling mill can be directly pressed down without adjusting the roll gap inclination of the rolling mill, and the rolling parameter at the moment is recorded as a parameter 1;

if the offset of the central line of the strip steel exceeds +/-12 mm or the wedge exceeds +/-120 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of a roll gap of the rolling mill to +/-2 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out trial rolling for the 2 nd time, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of the roll gap of the rolling mill to the horizontal plane +/-3 +0.5 +/-2 (N-2) ], then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected by the rolling mill outlet multifunctional instrument to meet the standard, and then carrying out continuous casting and rolling according to the parameter when the product meets the standard for the first time;

thirdly, if the offset of the central line of the strip steel exceeds +/-11 mm or the wedge exceeds +/-110 mu m when the strip steel is taken out of the rolling mill for the 1 st time, adjusting the inclination degree of the roll gap of the rolling mill to +/-1.5 degrees relative to the horizontal plane according to the detection result of a multifunctional instrument, then carrying out the 2 nd trial rolling, and recording the rolling parameter at the time as a parameter 2;

by analogy, if the offset of the central line of the strip steel exceeds +/-10 mm or the wedge exceeds +/-100 mu m when the strip steel is discharged from the rolling mill for the Nth time (N is an integer of 2-4), adjusting the inclination degree of a roll gap of the rolling mill to +/-2.5 +0.5 +/-2 (N-2) degrees relative to the horizontal plane according to the detection result of the multifunctional instrument, then carrying out trial rolling for the (N +1) th time, recording the rolling parameter as the parameter (N +1) until the strip steel is detected to be in accordance with the standard by the multifunctional instrument at the outlet of the rolling mill, and then carrying out continuous casting and rolling according to the parameter when the product is in accordance with the standard for the first time.

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