CN114289525B - Method for detecting and straightening head warpage of hot rolled steel plate - Google Patents

Abstract

The invention discloses a method for detecting and straightening the head warpage of a hot rolled steel plate, which specifically comprises the following steps: s1, setting a laser cold detection device; the laser cold inspection device is provided with a first height h ₁ Second height h ₂ … … nth height h _n The method comprises the steps of carrying out a first treatment on the surface of the A limit height H; s2, moving the steel plate to a cooling bed, and triggering an anti-straightening signal when the head of the steel plate shields the signal of the laser cold detection device; s3, the PLC control system receives the anti-straightening signal of the limit height H to stop straightening the steel plate, and operators manually cut off the warping part of the steel plate exceeding the limit height H; s4, automatically judging the nth height h with the highest execution height by the PLC control system _n Is a signal of inverse straightening; s5, straightening the rest part of the steel plate continuously after the hot straightening machine levels the head part of the steel plate. According to the invention, the opening height of the roll gap of the thermal straightener and the running direction of the straightener are controlled in a linkage manner by detecting the reverse straightening signal of the head warpage of the thermal straightening incoming steel plate, and the phenomenon of tilting the head is eliminated through the reverse straightening process of the thermal straightener, so that the steel plate is leveled.

Description

A method for detecting and straightening head warpage of hot-rolled steel plates

Technical field

The present invention relates to the technical field of steel rolling, specifically a method for detecting and straightening the warpage of the head of a hot-rolled steel plate.

Background technique

In the existing steel plate rolling production system, after the steel plate has completed the rolling process, some of the steel plates will have head warping before entering the hot straightening process, which is the "warped head" phenomenon. If a "cocked head" situation cannot be discovered and dealt with in time, after the steel plate enters the ultra-fast cooling process, the angle at which the cooling water is sprayed onto the surface of the steel plate will change. In this way, the cooling situation at the head and tail of the steel plate will be affected by the cooling process. That changed. Slight warping will affect the performance of the steel plate. When severe warping occurs, the steel plate will directly hit the main equipment of the cooling system, causing damage to the steel rolling cooling equipment.

The existing detection and prevention methods use manual observation to pick out unqualified steel plates, but manual inspection lacks specific quantitative detection methods. Therefore, there is an urgent need for a method for detecting and straightening the head warpage of hot-rolled steel plates.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for detecting and straightening the warpage of the head of a hot-rolled steel plate in view of the above-mentioned deficiencies in the prior art. The straightening signal is used to interlock to control the opening height of the roll gap of the hot straightening machine and the running direction of the straightening machine. The anti-straightening process of the hot straightening machine eliminates the "buck head" phenomenon and makes the steel plate flat.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

A method for detecting and straightening head warpage of hot-rolled steel plates, specifically including the following steps:

Step 1. The steel plate rolled by the rolling mill needs to pass the laser cold inspection device before entering the cooling bed; the transmitter and receiver of the laser cold inspection device are arranged on both sides of the steel plate in the forward direction and at the same height; the laser cold inspection device is set There are several sets of detection heights in the vertical direction, from low to high, they are the first height h ₁ , the second height h ₂ ,...the nth height h _n , where n is a positive integer; the laser cold inspection device settings also set There is a set of limit heights H, and the limit height H is higher than the nth height h _n ;

Step 2. The steel plate moves to the cooling bed through the conveyor roller. When the head of the steel plate warps and blocks the signal reception between the transmitter and receiver of the laser cold inspection device, the anti-straightening signal can be triggered. The anti-straightening signal is collected. Transmitted to the PLC control system;

Step 3. When the PLC control system receives the reverse straightening signal of the limit height H, the PLC control system automatically stops the straightening of the steel plate, and the screen alarm prompts the operator to manually cut off the warped part of the steel plate that exceeds the limit height H; After the straightening signal disappears, continue the straightening work;

Step 4. When the PLC control system receives the nth height h _n , the n-1th height h _n-1 , and... the first height h ₁ , it automatically determines and selects to perform the reverse straightening of the nth height h _n with the highest height. Signal: The roll gap of the hot straightening machine is raised by h _n +100mm, and the steel plate moves toward the cooling bed on the conveyor roller table until the head of the steel plate enters the hot straightening machine at a distance of 2 to 4 meters, and the roller pressure of the hot straightening machine resumes. During the straightening roll gap during normal operation, when the steel plate moves toward the rolling mill on the conveyor roller table until it exits the hot straightening machine, the head of the steel plate warps and is reverse-straightened by the hot straightening machine;

Step 5. After the hot straightening machine straightens the head of the steel plate, the steel plate continues to perform the normal straightening process to straighten the rest of the steel plate.

As a further preference of the present invention, if the signal of the laser cold inspection device is not blocked by the warpage of the steel plate head and the PLC control system does not receive the anti-straightening signal, the thermal straightening machine executes the normal straightening process, and the straightening direction is the rolling mill Toward the direction of the cooling bed; on the contrary, if the signal of the laser cold inspection device is blocked by the warpage of the steel plate head, when the PLC control system receives the anti-straightening signal, the hot straightening machine will perform the anti-straightening process, and the straightening direction will be cold The bed faces the direction of the rolling mill.

As a further preference of the present invention, the maximum height H of the steel plate is 350 mm.

As a further preference of the present invention, the laser cold detection device in step 1 is provided with 3 sets of detection heights, which are the first height h ₁ , the second height h ₂ and the third height h ₃ respectively; the first height h ₁ is 80~ 120mm, the second height _h2 is 130~170mm, and the third height _h3 is 180~220mm.

As a further preference of the present invention, the first height h ₁ is 100 mm, the second height h ₂ is 150 mm, and the third height h ₃ is 200 mm.

As a further preference of the present invention, the automatic determination logic of the PLC control system is: when the anti-straightening signals of the first height h ₁ , the second height h ₂ and the third height h ₃ are simultaneously collected, execute the third height h ₃ With the anti-straightening signal, the roll gap of the hot straightening machine is raised to 300mm, and the steel plate moves toward the cooling bed on the conveyor roller until the head of the steel plate enters the hot straightening machine at a distance of 4 meters; when the first height h ₁ is collected at the same time , the anti-straightening signal of the second height h ₂ , when the anti-straightening signal of the third height h ₃ is not collected, the anti-straightening signal of the second height h ₂ is executed, and the roll gap of the thermal straightening machine is raised to 250mm. The steel plate moves toward the cooling bed on the conveyor roller until the head of the steel plate enters the hot straightening machine at a distance of 3 meters; when the anti-straightening signal of the first height h ₁ is collected, the second height h ₂ and the third height are not collected. When the anti-straightening signal of h ₃ is reached, the anti-straightening signal of the first height h ₁ is executed, the roll gap of the hot straightening machine is raised to 200mm, and the steel plate moves toward the cooling bed on the conveyor roller table until the head of the steel plate enters the heat straightening The distance between the machine and the machine is 2 meters; when the anti-straightening signals of the first height h ₁ , the second height h ₂ and the third height h ₃ are not collected, the thermal straightening machine performs the normal straightening process.

The invention has the following beneficial effects:

1. The present invention can realize automatic monitoring of the warpage of the head of steel plates, replacing manual observation to screen out unqualified steel plates with head warps. The monitoring is accurate and reliable.

2. This invention can, when the warped height of the steel plate head exceeds the limit height H, the PLC control system screen alarm prompts the operator to manually cut off the warped part of the steel plate that exceeds the limit height H, ensuring the stable operation of the heat straightening process; the steel plate head warps When the warp height does not exceed the limit height H, the warpage height is judged by the laser cold inspection device, and the anti-straightening signal is automatically determined and fed back to the PLC control system to adjust the height of the roll gap of the thermal straightening machine and the entry of the steel plate head. The distance between the hot straightening machine and the counter-straightening steel plate makes the steel plate flat and meets the production requirements.

Description of the drawings

Figure 1 is a schematic diagram of a detection and straightening device for a method of detecting and straightening the head warpage of a hot-rolled steel plate according to the present invention.

Figure 2 is a schematic diagram of a laser cold inspection device for detecting and straightening the head warpage of hot-rolled steel plates according to the present invention.

Among them are: 1. Rolling mill; 2. Conveying roller table; 3. Thermal straightener; 4. Laser cold inspection device; 5. Cooling bed.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific preferred embodiments.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "left side", "right side", "upper part", "lower part", etc. are based on the orientation or positional relationship shown in the drawings, and are only In order to facilitate the description of the present invention and simplify the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and "first", "second", etc. do not refer to components. importance and therefore should not be construed as limitations of the invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of the present invention.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific preferred embodiments.

A method for detecting and straightening head warpage of hot-rolled steel plates, specifically including the following steps:

Step 1. Before entering the heat straightening process, some steel plates will have their heads warped, which is the phenomenon of "warped heads". If a "cocked head" situation cannot be discovered and dealt with in time, after the steel plate enters the ultra-fast cooling process, the angle at which the cooling water is sprayed onto the surface of the steel plate will change. In this way, the cooling situation at the head and tail of the steel plate will be affected by the cooling process. That changed. Slight warping will affect the performance of the steel plate. When severe warping occurs, the steel plate will directly hit the main equipment of the cooling system, causing damage to the steel rolling cooling equipment. As shown in Figure 1, the steel plate rolled by the rolling mill 1 needs to pass through the laser cold inspection device 4 before entering the cooling bed 5. The laser cold inspection device 4 can realize automatic monitoring of the warpage of the steel plate head, replacing manual observation and screening. Unqualified steel plates with warped heads are monitored accurately and with high reliability.

As shown in Figure 2, the transmitter and receiver of the laser cold inspection device 4 are respectively arranged on both sides of the steel plate in the forward direction and at the same height; the laser cold inspection device 4 is provided with several sets of detection heights in the vertical direction, from low to The heights are respectively the first height h ₁ , the second height h ₂ ,...the nth height h _n , where n is a positive integer; the laser cold inspection device 4 is also provided with a set of limit heights H, and the limit height H is higher than the nth height h _n .

Step 2. The steel plate moves to the cooling bed through the conveyor roller 2. When the head of the steel plate warps and blocks the signal reception between the transmitter and the receiver of the laser cold inspection device 4, the anti-straightening signal can be triggered. The anti-straightening signal After collection, it is transmitted to the PLC control system.

If the signal from the laser cold inspection device 4 is not blocked by the warpage of the steel plate head and the PLC control system does not receive the anti-straightening signal, the hot straightening machine 3 performs the normal straightening process, and the straightening direction is the rolling mill 1 towards the cooling bed 5 direction; on the contrary, if the signal of the laser cold inspection device 4 is blocked by the warpage of the steel plate head, when the PLC control system receives the anti-straightening signal, the thermal straightening machine 3 executes the anti-straightening process, and the straightening direction is the cooling bed 5 towards the direction of rolling mill 1.

Step 3. When the PLC control system receives the anti-straightening signal of the limit height H, the PLC control system automatically stops straightening the steel plate, and the screen alarm prompts the operator to manually cut off the warped part that exceeds the limit height H of the steel plate; the limit height H After the anti-straightening signal disappears, continue the straightening work.

Step 4. When the PLC control system receives the anti-straightening signals of the nth height h _n , the n-1th height h _n-1 , ... the first height h ₁ , it automatically determines and selects the nth height h with the highest execution height. _n reverse straightening signal; the gap between the rollers of the hot straightening machine 3 is raised h _n +100mm, and the steel plate moves toward the cooling bed on the conveyor roller 2 until the head of the steel plate enters the hot straightening machine 3 for a distance of 2 to 4 meters Afterwards, the roller 3 of the hot straightening machine is pressed down to restore the straightening roll gap during normal operation. The steel plate moves towards the direction of the rolling mill 1 on the conveyor roller table 2 until the head of the steel plate exits the hot straightening machine 3. The head of the steel plate becomes warped. The curve is straightened and smoothed by the heat straightening machine 3.

Step 5. After the hot straightening machine 3 straightens the head of the steel plate, the steel plate continues to perform the normal straightening process to straighten the rest of the steel plate.

The laser cold inspection device 4 in step 1 is provided with 3 sets of detection heights, which are the first height h ₁ , the second height h ₂ and the third height h ₃ respectively; the first height h ₁ is 80~120mm, and the second height h ₂ is 130~170mm, and the third height _h3 is 180~220mm.

Further introduction will be made below in conjunction with the preferred embodiment 1.

Objectively speaking, based on the objective limitations of the performance of the thermal straightening machine 3 equipment itself and the quality of the incoming steel plate, the warping position of the steel plate that needs to be straightened is basically located at the head of the steel plate, and generally warping occurs The ultimate height is 350mm. A steel plate with a warpage height exceeding 350mm is an unqualified steel plate and loses the need for straightening. Therefore, the maximum height H of the steel plate is 350mm. On this basis, the first height h ₁ is 100mm, the second height h ₂ is 150mm, and the third height h ₃ is 200mm, which are the optimal detection height settings of the present invention.

When the anti-straightening signals of the first height h ₁ , the second height h ₂ and the third height h ₃ are collected at the same time, the anti-straightening signal of the third height h ₃ is executed, and the roller gap of the thermal straightening machine 3 is raised to 300mm, the steel plate moves on the conveyor roller 2 in the direction of the cooling bed 5 until the head of the steel plate enters a distance of 4 meters in the hot straightening machine 3; when the reverse straightening of the first height h ₁ and the second height h ₂ is collected at the same time signal, when the anti-straightening signal at the third height h ₃ is not collected, the anti-straightening signal at the second height h ₂ is executed. The gap between the rollers of the hot straightening machine 3 is raised to 250mm, and the steel plate moves toward the cold conveyor on the conveyor roller 2. The bed 5 moves in the direction until the head of the steel plate enters a distance of 3 meters into the hot straightening machine 3; when the anti-straightening signal at the first height h ₁ is collected, the anti-straightening signal at the second height h ₂ and the third height h ₃ is not collected. When the straightening signal is issued, the anti-straightening signal of the first height h ₁ is executed, the roll gap of the hot straightening machine 3 is raised to 200mm, and the steel plate moves on the conveyor roller 2 towards the cooling bed 5 until the head of the steel plate enters the hot straightening A distance of 2 meters within the machine 3; when the anti-straightening signals of the first height h ₁ , the second height h ₂ and the third height h ₃ are not collected, the thermal straightening machine 3 performs the normal straightening process.

The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention. These equivalent transformations All belong to the protection scope of the present invention.

Claims (6)

1. A method for detecting and straightening the warpage of the head of a hot rolled steel plate is characterized by comprising the following steps: the method specifically comprises the following steps:

step 1, a steel plate rolled by a rolling mill (1) passes through a laser cold detection device (4) before entering a cooling bed (5); the transmitters and the receivers of the laser cold detection device (4) are respectively arranged at two sides of the advancing direction of the steel plate and are positioned at the same height; laser cold inspection deviceThe device (4) is provided with a plurality of groups of detection heights in the vertical direction, and the detection heights are respectively the first height h from low to high ₁ Second height h ₂ … … nth height h _n Wherein n is a positive integer; the laser cold inspection device (4) is also provided with a group of limit height H, and the limit height H is higher than the nth height H _n ；

Step 2, the steel plate moves to a cooling bed through a conveying roller way (2), when the head of the steel plate warps and shields signal receiving between a transmitter and a receiver of a laser cold detection device (4), an anti-straightening signal can be triggered, and the anti-straightening signal is collected and transmitted to a PLC control system;

step 3, when the PLC control system receives an anti-straightening signal with the limit height H, the PLC control system automatically stops straightening the steel plate, and a picture alarm prompts an operator to manually cut off a warping part exceeding the limit height H of the steel plate; after the anti-straightening signal with the limit height H disappears, continuing to straighten;

step 4, when the PLC control system receives the nth height h _n N-1 h _n-1 … … first height h ₁ When the inverse straightening signal of (2) is received, the n-th height h with the highest execution height is automatically determined and selected _n Is a signal of inverse straightening; roll gap lifting h of thermal straightener (3) _n After the steel plate moves on the conveying roller way (2) towards the direction of the cooling bed until the steel plate head enters the thermal straightener (3) for a distance of 2-4 meters, the roller of the thermal straightener (3) is pressed down to restore the straightening roller gap when the thermal straightener (3) operates normally, and the steel plate moves on the conveying roller way (2) towards the direction of the rolling mill (1) until the steel plate head exits the thermal straightener (3), and the steel plate head is reversely straightened and flattened by the thermal straightener (3) in the process of the steel plate head exiting the thermal straightener (3);

and 5, after the head of the steel plate is leveled by the hot leveler (3), the steel plate continues to execute a normal straightening process, and the rest part of the steel plate is straightened.

2. The method for detecting and straightening the head warp of the hot rolled steel sheet according to claim 1, wherein: in the step 2, if the signal of the laser cold detection device (4) is not blocked by the warpage of the steel plate head, the hot straightening machine (3) executes a normal straightening process when the PLC control system does not receive the anti-straightening signal, and the straightening direction is the direction of the rolling mill (1) towards the cooling bed (5); otherwise, if the signal of the laser cold checking device (4) is blocked by the warpage of the steel plate head, the hot straightening machine (3) executes a reverse straightening process when the PLC control system receives the reverse straightening signal, and the straightening direction is the direction of the cooling bed (5) towards the rolling mill (1).

3. The method for detecting and straightening the head warp of the hot rolled steel sheet according to claim 1, wherein: the limit height H of the steel plate in the step 1 is 350mm at maximum.

4. The method for detecting and straightening the head warp of the hot rolled steel sheet according to claim 1, wherein: the laser cold detection device (4) in the step 1 is provided with 3 groups of detection heights, namely a first height h ₁ Second height h ₂ And a third height h ₃ The method comprises the steps of carrying out a first treatment on the surface of the First height h ₁ 80-120 mm, a second height h ₂ 130-170 mm, a third height h ₃ 180-220 mm.

5. The method for detecting and straightening head warp of a hot rolled steel sheet according to claim 4, wherein: first height h ₁ 100mm, a second height h ₂ 150mm, a third height h ₃ 200mm.

6. The method for detecting and straightening head warp of a hot rolled steel sheet according to claim 5, wherein: when the first height h is collected simultaneously ₁ Second height h ₂ And a third height h ₃ Performs a third height h when the signal is anti-straightened ₃ The roll gap of the hot straightening machine (3) is raised to 300mm, and the steel plate moves on the conveying roller way (2) towards the direction of the cooling bed (5) until the head of the steel plate enters the hot straightening machine (3) for a distance of 4 meters; when the first height h is collected simultaneously ₁ Second height h ₂ Is not acquired at the third height h ₃ Performs a second height h when the signal is anti-straightened ₂ Is a reverse straightening letterThe roll gap of the hot straightening machine (3) is raised to 250mm, and the steel plate moves on the conveying roller way (2) towards the direction of the cooling bed (5) until the head of the steel plate enters the hot straightening machine (3) for a distance of 3 meters; when the first height h is acquired ₁ Is not acquired at a second height h ₂ Third height h ₃ Performs a first height h when the signal is anti-straightened ₁ The roll gap of the hot straightening machine (3) is raised to 200mm, and the steel plate moves on the conveying roller way (2) towards the direction of the cooling bed (5) until the head of the steel plate enters the hot straightening machine (3) for a distance of 2 meters; at a first height h ₁ Second height h ₂ And a third height h ₃ When none of the anti-straightening signals is acquired, the thermal straightener (3) executes a normal straightening process.