阅读说明：本技术 一种提高低温卷取温度精度的层流冷却控制方法 (Laminar cooling control method for improving low-temperature coiling temperature precision ) 是由 邢伟 宋晓娟 王继军 张波 秦红波 师可新 邝霜 令狐克志 金鑫 于 2021-08-09 设计创作，主要内容包括：本发明涉及一种提高低温卷取温度精度的层流冷却控制方法,属于热轧方法技术领域。本发明的技术方案是：获取当前轧制带钢的卷取温度信息；以50℃为基础分别设定了N种上下集管不均匀冷却的模式,从N种上下不均匀冷却设定模式中确定出与当前轧制带钢的卷取温度匹配的上下不均匀的设定模式,根据上下集管不均匀冷却的模式确定不均匀冷却集管开启的位置,由执行设备启用相应的集管开启水阀。本发明的有益效果是：根据每次轧制带钢的卷取温控信息自动设置上下不均匀冷却模式,通过在卷取带钢前减少上集管的冷却速率,提高了低温卷取温度检测精度,从而使得层冷控制的温度更准确、控制更准时,因此可以提高卷取温度控制精度,以使成品质量更稳定。(The invention relates to a laminar cooling control method for improving low-temperature coiling temperature precision, and belongs to the technical field of hot rolling methods. The technical scheme of the invention is as follows: acquiring coiling temperature information of the currently rolled strip steel; n types of uneven cooling modes of the upper header and the lower header are respectively set on the basis of 50 ℃, an uneven setting mode matched with the coiling temperature of the current rolled strip steel is determined from the N types of uneven cooling setting modes, the opening position of the uneven cooling header is determined according to the uneven cooling modes of the upper header and the lower header, and the corresponding header opening water valve is started by the execution equipment. The invention has the beneficial effects that: the upper and lower uneven cooling modes are automatically set according to the coiling temperature control information of rolled strip steel every time, and the low-temperature coiling temperature detection precision is improved by reducing the cooling rate of the upper collecting pipe before coiling the strip steel, so that the temperature of laminar cooling control is more accurate and more timely in control, and the coiling temperature control precision can be improved, and the quality of finished products is more stable.)

1. A laminar cooling control method for improving the precision of low-temperature coiling temperature is characterized by comprising the following steps:

(1) the method comprises the steps that a process automation system of a rolling mill obtains coiling temperature control information of a currently rolled strip steel;

(2) the process automation system determines the cooling temperature and the cooling rate of the upper and lower collecting pipes, which start the up-and-down uneven cooling with the current rolled strip steel, from the N uneven cooling modes of the upper and lower collecting pipes according to the corresponding relation between the coiling temperature control information of the current rolled strip steel and the N uneven cooling modes of the upper and lower collecting pipes;

(3) and the process automation system determines the opening position of the uneven cooling header according to the uneven cooling mode of the upper header and the lower header and transmits information to the basic automation system, the basic automation system sends the set uneven cooling mode of the upper header and the lower header to an on-site execution mechanism, and the execution device starts the corresponding header to open the water valve.

2. The laminar cooling control method for improving the accuracy of the low-temperature coiling temperature according to claim 1, characterized in that: in the step (1), the coiling temperature control information comprises target coiling temperature and cooling rate parameters of the strip steel.

3. The laminar cooling control method for improving the accuracy of the low-temperature coiling temperature according to claim 1, characterized in that: in the step (2), N types of modes of uneven cooling of the upper and lower headers, each representing that the cooling temperature is set to 100 ℃, 150 ℃, 200 ℃, 250 ℃, 300 ℃, 350 ℃, 400 ℃ and 450 ℃ on the basis of 50 ℃, respectively, include four levels of 0%, 25%, 50% and 75% with respect to the cooling rate setting of the upper header, and include four levels of 25%, 50%, 75% and 100% with respect to the cooling rate setting of the lower header.

4. The laminar cooling control method for improving the accuracy of the low-temperature coiling temperature according to claim 3, characterized in that: the upper and lower header non-uniform cooling pattern comprises: starting the cooling starting temperature of the upper and lower uneven cooling; the cooling rate of the upper header and the cooling rate of the lower header.

5. The laminar cooling control method for improving the accuracy of the low-temperature coiling temperature according to claim 1, characterized in that: and the method also comprises the following steps of dynamically calculating according to the starting temperature and the cooling mode of the non-uniform cooling mode of the upper header and the lower header and the non-uniform cooling mode from the moment that the currently rolled strip steel enters the laminar cooling area, determining the next set data, and transmitting the result to the execution equipment for on-site header boiling water control.

Technical Field

The invention relates to a laminar cooling control method for improving low-temperature coiling temperature precision, and belongs to the technical field of hot rolling methods.

Background

In the production process of hot rolled strip steel, a laminar cooling device is required to be used for cooling the strip steel after rolling and before coiling, and ideal metallographic structure and mechanical properties are obtained by controlling the coiling temperature and the cooling rate of the strip steel. The sub-cooling zone is defined from the finish rolling outlet pyrometer to the underground crimper inlet pyrometer. The laminar cooling area is divided into a rough cooling area and a fine cooling area. Wherein the 1 st to 15 th groups of headers are rough cooling areas, and the 16 th, 17 th and 18 th groups of headers are fine cooling areas.

In the prior art, the cooling rate cannot be adjusted at a certain cooling temperature to realize vertically uneven cooling, so that the hot rolled strip, particularly the low-temperature coiled strip which is less than or equal to 500 ℃, is difficult to sweep due to the low-temperature plate surface Leidenfrost effect, when the cooling rate of an upper header is set to be large, the accumulated water on the plate surface is difficult to sweep, the detection of the plate surface temperature is influenced, the actual detected coiling temperature fluctuation is large, the coiling temperature control precision is influenced by the temperature detection value, the quality of a steel coil finished product is further influenced, and the large low-temperature coiling temperature fluctuation becomes the production problem of each hot rolling production line.

Disclosure of Invention

The invention aims to provide a laminar cooling control method for improving the precision of low-temperature coiling temperature, which automatically sets a vertically uneven cooling mode according to coiling temperature control information of rolled strip steel every time, and improves the detection precision of the low-temperature coiling temperature by reducing the cooling rate of an upper header before coiling the strip steel, so that the temperature of laminar cooling control is more accurate and more timely, the control precision of the coiling temperature can be improved, the quality of a finished product is more stable, and the problems in the background art are effectively solved.

The technical scheme of the invention is as follows: a laminar cooling control method for improving the precision of low-temperature coiling temperature comprises the following steps:

(1) the method comprises the steps that a process automation system of a rolling mill obtains coiling temperature control information of a currently rolled strip steel;

(2) the process automation system determines the cooling temperature and the cooling rate of the upper and lower collecting pipes, which start the up-and-down uneven cooling with the current rolled strip steel, from the N uneven cooling modes of the upper and lower collecting pipes according to the corresponding relation between the coiling temperature control information of the current rolled strip steel and the N uneven cooling modes of the upper and lower collecting pipes;

(3) and the process automation system determines the opening position of the uneven cooling header according to the uneven cooling mode of the upper header and the lower header and transmits information to the basic automation system, the basic automation system sends the set uneven cooling mode of the upper header and the lower header to an on-site execution mechanism, and the execution device starts the corresponding header to open the water valve.

In the step (1), the coiling temperature control information comprises target coiling temperature and cooling rate parameters of the strip steel.

In the step (2), N types of modes of uneven cooling of the upper and lower headers, each representing that the cooling temperature is set to 100 ℃, 150 ℃, 200 ℃, 250 ℃, 300 ℃, 350 ℃, 400 ℃ and 450 ℃ on the basis of 50 ℃, respectively, include four levels of 0%, 25%, 50% and 75% with respect to the cooling rate setting of the upper header, and include four levels of 25%, 50%, 75% and 100% with respect to the cooling rate setting of the lower header.

The upper and lower header non-uniform cooling pattern comprises: starting the cooling starting temperature of the upper and lower uneven cooling; the cooling rate of the upper header and the cooling rate of the lower header.

And the method also comprises the following steps of dynamically calculating according to the starting temperature and the cooling mode of the non-uniform cooling mode of the upper header and the lower header and the non-uniform cooling mode from the moment that the currently rolled strip steel enters the laminar cooling area, determining the next set data, and transmitting the result to the execution equipment for on-site header boiling water control.

The invention has the beneficial effects that: the upper and lower uneven cooling modes are automatically set according to the coiling temperature control information of rolled strip steel every time, and the low-temperature coiling temperature detection precision is improved by reducing the cooling rate of the upper collecting pipe before the strip steel is coiled, so that the temperature of laminar cooling control is more accurate and more accurate in control, and the coiling temperature control precision can be improved, and the quality of finished products is more stable.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer and more complete, the following describes technical solutions of the embodiments of the present invention clearly, and it is obvious that the described embodiments are a small part of the embodiments of the present invention, not all embodiments, and all other embodiments obtained by a person of ordinary skill in the art without creative work based on the embodiments of the present invention belong to the protection scope of the present invention.

A laminar cooling control method for improving the precision of low-temperature coiling temperature comprises the following steps:

(1) the method comprises the steps that a process automation system of a rolling mill obtains coiling temperature control information of a currently rolled strip steel;

(2) the process automation system determines the cooling temperature and the cooling rate of the upper and lower collecting pipes, which start the up-and-down uneven cooling with the current rolled strip steel, from the N uneven cooling modes of the upper and lower collecting pipes according to the corresponding relation between the coiling temperature control information of the current rolled strip steel and the N uneven cooling modes of the upper and lower collecting pipes;

(3) and the process automation system determines the opening position of the uneven cooling header according to the uneven cooling mode of the upper header and the lower header and transmits information to the basic automation system, the basic automation system sends the set uneven cooling mode of the upper header and the lower header to an on-site execution mechanism, and the execution device starts the corresponding header to open the water valve.

In the step (1), the coiling temperature control information comprises target coiling temperature and cooling rate parameters of the strip steel.

In the step (2), N types of modes of uneven cooling of the upper and lower headers, each representing that the cooling temperature is set to 100 ℃, 150 ℃, 200 ℃, 250 ℃, 300 ℃, 350 ℃, 400 ℃ and 450 ℃ on the basis of 50 ℃, respectively, include four levels of 0%, 25%, 50% and 75% with respect to the cooling rate setting of the upper header, and include four levels of 25%, 50%, 75% and 100% with respect to the cooling rate setting of the lower header.

The upper and lower header non-uniform cooling pattern comprises: starting the cooling starting temperature of the upper and lower uneven cooling; the cooling rate of the upper header and the cooling rate of the lower header.

And the method also comprises the following steps of dynamically calculating according to the starting temperature and the cooling mode of the non-uniform cooling mode of the upper header and the lower header and the non-uniform cooling mode from the moment that the currently rolled strip steel enters the laminar cooling area, determining the next set data, and transmitting the result to the execution equipment for on-site header boiling water control.

A laminar cooling device is arranged in a laminar cooling area on a hot-rolled strip steel production line, and the laminar cooling area is divided into a coarse cooling area and a fine cooling area. Wherein the 1 st to 15 th group of collecting pipes are rough cooling areas, the 16 th, 17 th and 18 th group of collecting pipes are fine cooling areas, the coiling temperature of the steel used by the invention is set to be less than or equal to 500 ℃, and the method comprises the following specific steps: acquiring the strip steel coiling temperature information of the currently rolled strip steel; n types of uneven cooling modes of the upper header and the lower header are respectively set on the basis of 50 ℃, and an upper uneven setting mode matched with the coiling temperature of the current rolled strip steel is determined from the N types of upper uneven cooling setting modes, wherein the N types of upper uneven cooling modes and the lower uneven cooling modes respectively represent different upper uneven cooling modes which are set by reducing the cooling rate of the upper header at a cooling temperature. The invention solves the technical problem of large Leidenfrost effect cooling temperature fluctuation in low-temperature coiling at the field of hot rolled strip steel production of less than or equal to 500 ℃ in the prior art, improves the coiling temperature control precision, and ensures that the finished product quality meets the requirements and is more stable because the upper and lower uneven cooling is the correction of the cooling mode before coiling the strip steel.

1. Coiling temperature control information acquisition: coiling temperature information of the current rolled strip steel is automatically obtained by the process of a rolling mill, and the coiling temperature control information comprises: the target coiling temperature and cooling rate parameters of the strip steel are partially shown in the table 1:

2. determination of the pattern of uneven cooling of the upper and lower headers: according to the corresponding relation (table 2) of the coiling temperature and the cooling rate parameter of the strip steel and the uneven cooling modes of the N upper and lower collecting pipes, the process control system determines the cooling temperature and the cooling rate of the upper and lower collecting pipes, which start the uneven cooling with the current rolled strip steel, from the uneven cooling modes of the N upper and lower collecting pipes by the process automation system (table 3).

Table 2: n kinds of modes (parts) for uneven cooling of upper and lower headers

TABLE 3 correspondence of steel type Properties with differential Cooling modes (part)

3. And (3) field execution: and determining the opening position of the uneven cooling manifold by the process automation system according to the upper and lower uneven cooling modes and transmitting information to the basic automation system, sending the set upper and lower uneven cooling modes to an on-site execution mechanism by the basic automation system, and starting the corresponding manifold to open the water valve by the execution equipment. Starting from the moment that the currently rolled strip steel enters the laminar cooling area, dynamically calculating according to the temperature and the cooling mode of the uneven cooling mode according to the preset uneven cooling mode and determining the next set data; and passes the results to the enforcement device.

Example 1: the production method of the FB510L hot-rolled girder steel adopts the following specific process.

(1) Coiling temperature control information acquisition: the method comprises the steps of automatically acquiring the strip steel coiling temperature information of the current rolled strip steel by the process of a rolling mill, setting the target coiling temperature of the strip steel to be 480 ℃, setting the cooling rate to be 100%, and setting the steel type attribute of the strip steel to be 5.

(2) Determination of the pattern of uneven cooling of the upper and lower headers: and determining that the control mode of starting up-down uneven cooling corresponding to the attribute 5 of the current rolled strip steel type is C-04, the corresponding cooling temperature is 450 ℃, the corresponding cooling rate of the upper header is 25% and the cooling rate of the lower header is 75% from the N modes of uneven cooling of the upper header and the lower header by a process automation system.

(3) And (3) field execution: and determining the opening position of the uneven cooling manifold by the process automation system according to the upper and lower uneven cooling modes and transmitting information to the basic automation system, sending the set upper and lower uneven cooling modes to an on-site execution mechanism by the basic automation system, and starting the corresponding manifold to open the water valve by the execution equipment. Starting from the moment that the currently rolled strip steel enters the laminar cooling area, dynamically calculating according to the temperature and the cooling mode of the uneven cooling mode according to the preset uneven cooling mode and determining the next set data; and passes the results to the enforcement device.

The coiling temperature of the FB510L hot rolled girder steel obtained in the embodiment is actually controlled to be +/-18 ℃ of a target, the coiling temperature fluctuation is small, and the mechanical property is tested, and the actual performance is (longitudinal): tensile strength 565MPa, yield strength 478MPa, and elongation 28%.

Example 2: the production method of the TKDC hot-rolled strapping steel adopts the following specific process.

(1) Coiling temperature control information acquisition: the process system of the rolling mill acquires the strip steel coiling temperature control information of the currently rolled strip steel, the target coiling temperature of the strip steel is 440 ℃, the cooling rate is set to be 75%, and the steel type attribute of the strip steel is 22.

(2) Determination of the pattern of uneven cooling of the upper and lower headers: and determining that the control mode of starting up-down uneven cooling corresponding to the attribute 22 of the current rolled steel strip steel type is C-07, the corresponding cooling temperature is 400 ℃, the corresponding cooling rate of the upper header is 25 percent, and the cooling rate of the lower header is 50 percent from the N modes of uneven cooling of the upper header and the lower header by a process automation system.

(3) And (3) field execution: and determining the opening position of the uneven cooling manifold by the process automation system according to the upper and lower uneven cooling modes and transmitting information to the basic automation system, sending the set upper and lower uneven cooling modes to an on-site execution mechanism by the basic automation system, and starting the corresponding manifold to open the water valve by the execution equipment. Starting from the moment that the currently rolled strip steel enters the laminar cooling area, dynamically calculating according to the temperature and the cooling mode of the uneven cooling mode according to the preset uneven cooling mode and determining the next set data; and passes the results to the enforcement device.

The coiling temperature of the TKDC hot-rolled strip steel obtained in the embodiment is actually controlled to be +/-20 ℃ of a target, the coiling temperature fluctuation is small, and the mechanical property is tested, and the actual performance is (longitudinal): tensile strength of 678MPa, yield strength of 570MPa, and elongation of 21.5%.

Example 3: the production method of 590HES hot-rolled automobile structural steel adopts the following specific process.

(1) Coiling temperature control information acquisition: the method comprises the steps of automatically acquiring the strip steel coiling temperature information of the current rolled strip steel by the process of a rolling mill, setting the target coiling temperature of the strip steel to be 450 ℃, setting the cooling rate to be 50%, and setting the steel type attribute of the strip steel to be 19.

(2) Determination of the pattern of uneven cooling of the upper and lower headers: and determining that the control mode of starting up-down uneven cooling corresponding to the attribute 19 of the current rolled strip steel type is C-06, the corresponding cooling temperature is 400 ℃, the corresponding cooling rate of the upper header is 0 percent, and the cooling rate of the lower header is 50 percent from the N modes of uneven cooling of the upper header and the lower header by a process automation system.

(3) And (3) field execution: and determining the opening position of the uneven cooling manifold by the process automation system according to the upper and lower uneven cooling modes and transmitting information to the basic automation system, sending the set upper and lower uneven cooling modes to an on-site execution mechanism by the basic automation system, and starting the corresponding manifold to open the water valve by the execution equipment. Starting from the moment that the currently rolled strip steel enters the laminar cooling area, dynamically calculating according to the temperature and the cooling mode of the uneven cooling mode according to the preset uneven cooling mode and determining the next set data; and passes the results to the enforcement device.

The coiling temperature of the 590HES hot-rolled automobile structural steel obtained in the embodiment is actually controlled to be +/-17 ℃ of a target, the coiling temperature fluctuation is small, and the mechanical property is tested, and the actual property is (longitudinal): tensile strength of 650MPa, yield strength of 592MPa, and elongation of 19%.

The invention has the advantages that:

1. the coiling temperature is controlled stably: the invention solves the technical problem of large LadunFloist effect cooling temperature fluctuation in low-temperature coiling at the temperature of less than or equal to 500 ℃ on site in hot rolled strip steel production in the prior art, improves the coiling temperature control precision, and reduces the coiling temperature fluctuation from the fluctuation of a target value of +/-50 ℃ to the target value of +/-20 ℃ by using four-stage cooling process.

2. The physical properties are stable: the invention can set the initial temperature of the uneven cooling mode, and the cooling modes before and after the initial temperature can be separately set, wherein the independent setting of the cooling mode before the initial temperature is favorable for controlling the physical performance, the uneven cooling mode setting after the initial temperature is favorable for solving the problem of large fluctuation of the low-temperature Leidenfrost effect coiling temperature, and the independent setting of the cooling mode is favorable for stabilizing the physical performance.

3. The cooling path is more abundant: the invention adds a cooling mode to adjust the initial temperature before the strip steel is coiled in the layer cooling path, and different cooling rates can be set before and after the temperature is taken as a boundary, thereby being beneficial to the development and the use of other new steel types.