Method and device for calculating the initial thermal crown of a high-speed steel roller at the start of a new rolling campaign

Abstract

The present application relates to a kind of method and device for calculating the initial thermal crown of high-speed steel roller repeated on machine, belong to metallurgical industry hot rolling method and device technical field.The technical scheme of the present application is: when roller is off machine, the roller thermal crown based on roller number and off machine time are collected, and are stored to database;When executing roll change operation, i.e., when roller is on machine, the roller thermal crown and off machine time of last off machine of current roller number are called from database;Determine whether the roller is repeated on machine, if it is not repeated on machine, then determine the thermal crown as 0, if it is repeated on machine, then calculate the thermal crown of high-speed steel roller repeated on machine based on the determined calculation method;The thermal crown calculation value of high-speed steel roller repeated on machine is given to shape model, for roller gap crown calculation.The beneficial effects of the present application are: by establishing the roller thermal crown calculation method based on roller off machine thermal crown and time interval, the initial thermal crown of roller repeated on machine is calculated, and the calculation value is used for shape calculation after roll change, ensure the shape setting precision and control effect of first piece strip steel after roll change.

Description

TECHNICAL FIELD

[0001] The application relates to a method and a device for calculating the initial thermal crown of a high-speed steel roller repeatedly put on a machine, and belongs to the technical field of hot rolling methods and devices in the metallurgical industry. BACKGROUND

[0002] In the technical field of hot rolling, the application of high-speed steel rollers is an important part of the development of modern steel rolling production and is another major reform after the development of micro-alloying and controlled rolling and controlled cooling technologies. Compared with ordinary rollers, high-speed steel rollers should have good wear resistance and be widely used in the rolling production of plates, steel sections, bars and other fields, which can effectively reduce the roller consumption cost per ton of steel and improve the product competitiveness. Based on the excellent wear resistance of high-speed steel rollers, the high-speed steel roller is ground once and put on the machine for 4-6 times, and in some cases, the high-speed steel roller is put on the machine for more than 8 times. That is, the high-speed steel roller replaced by finishing rolling is placed for a few hours without grinding and is repeatedly put on the machine to reduce the roller consumption.

[0003] In the process of implementing the present application, the applicant found at least the following shortcomings in the prior art:

[0004] In the prior art, the thermal crown of the roller in the on-machine state can be calculated in real time based on the roller model, which is used to calculate the roll gap crown to ensure good strip shape. When the high-speed steel roller is repeatedly put on the machine, the roller still has thermal crown due to the short placement time and the lack of grinding. However, due to the lack of a method for predicting the initial crown of the high-speed steel roller repeatedly put on the machine, the roller model cannot obtain the thermal crown of the high-speed steel roller repeatedly put on the machine, resulting in deviation in the accuracy of calculating the roll gap crown.

[0005] Patent CN115401076A discloses a method for improving the shape of a plate by applying the thermal crown compensation of a high-speed steel roller. The method measures the actual roller temperature, establishes a roller temperature prediction model, obtains a predicted roller temperature, compares the predicted roller temperature with the actual temperature, calculates the corresponding thermal crown according to the roller temperature, automatically adjusts the bending roller force model to improve the plate shape. The method needs to ensure that the roller stably rolls 30 strips of steel, and the center temperature of the roller is greater than 50 DEG C. The cooling water is closed at the first time after the tail of the last strip of steel is thrown, and the roller temperature needs to be measured manually multiple times. The method has harsh application conditions, multiple manual operation steps, is not suitable for large-scale production, and cannot improve the plate shape from the source. SUMMARY

[0006] The application aims to provide a method and device for calculating the initial thermal crown of a high-speed steel roller when repeatedly put on a machine, by establishing a roller thermal crown calculation method based on the roller off-machine thermal crown and time interval, calculating the initial thermal crown of the roller when repeatedly put on a machine, and using the calculation value for plate shape calculation after roller replacement, to ensure the plate shape setting accuracy and control effect of the first plate steel after roller replacement, and effectively solve the above problems in the background art.

[0007] The technical solution of the application is a method for calculating the initial thermal crown of a high-speed steel roller when repeatedly put on a machine, comprising the following steps:

[0008] Step 101: When the roller is off the machine, the roller thermal crown based on the roller number and the off-machine time are collected and stored in a database.

[0009] Step 102: When the roller replacement operation is performed, i.e. when the roller is put on the machine, the roller thermal crown and off-machine time of the last off-machine of the current roller number are called from the database.

[0010] Step 103: It is judged whether the roller is repeatedly put on the machine. If not, the thermal crown is determined to be 0. If yes, the thermal crown of the high-speed steel roller when repeatedly put on the machine is calculated based on the determined calculation method.

[0011] Step 104: The thermal crown calculation value of the high-speed steel roller when repeatedly put on the machine is given to the plate shape model for roller gap crown calculation.

[0012] In the step 101, if the record of the current roller number does not exist in the database, a new record is generated for storage. If the record of the current roller number already exists, the roller thermal crown and off-machine time are updated.

[0013] In the step 102, if the record based on the current roller number does not exist, the roller thermal crown is set to 0 and the off-machine time is set to a default time.

[0014] The default time is set to 1970-01-01 00:00:00, which represents 0:00:00 on January 1, 1970.

[0015] In the step 103, the repeated on-machine judgment method is based on the on-machine number in the roller information. The last on-machine number of the roller is initially 0. After each grinding, the last on-machine number of the roller is reset to 0. After the roller is put on the machine, the last on-machine number of the roller is increased by 1. Therefore, when the roller is put on the machine, the corresponding last on-machine number is determined. If the last on-machine number is 0, it is judged as non-repeated on-machine. Otherwise, it is judged as repeated on-machine.

[0016] In the step 103, the determined calculation method is based on the thermal crown and off-machine time of the last off-machine of the roller and the current on-machine time. Specifically, it is expressed by a function relationship as follows:

[0017]

[0018] wherein C v is the thermal crown of the roll at the current on-machine time;

[0019] C0is the thermal crown of the roll at the last off-machine time;

[0020] e is the natural logarithm;

[0021] t n is the current on-machine time of the roll;

[0022] t0is the last off-machine time of the roll;

[0023] T is a time constant, set to T = 3600, in minutes;

[0024] f(t n ,t0) represents the time difference between the current on-machine time t n and the last off-machine time t0, in minutes;

[0025] C f is a correction factor, having a value in the range of 0.8 to 1.2, and can be set to different values for different stands.

[0026] In the step 104, the calculated thermal crown of the roll at the current on-machine time is used to compensate the roll crown when setting the shape of the first strip after roll change, so as to ensure the setting accuracy and control effect of the shape of the first strip after roll change, and the thermal crown self-learning value of the roll is used from the second strip.

[0027] A device for calculating the initial thermal crown of a high-speed steel roll at the repeated on-machine time, comprising a data acquisition module, a data calling module, a calculation module and a data transmission module, wherein the data acquisition module is connected to the input end of the roll and the database, the data calling module is connected to the output end of the database and the calculation module, the output end of the calculation module is connected to the data transmission module, and the data transmission module is connected to the shape model.

[0028] The data acquisition module is used to acquire the thermal crown of the current roll number and the off-machine time when the roll is off-machine, and store them in the database; the data calling module is used to call the thermal crown of the last off-machine time and the off-machine time of the current roll number from the database when the roll is on-machine; the calculation module is used to calculate the thermal crown of the high-speed steel roll at the repeated on-machine time; and the data transmission module is used to transmit the calculated thermal crown of the high-speed steel roll at the repeated on-machine time to the shape model, for calculating the roll gap crown of the roll.

[0029] The beneficial effect of the present application is that by establishing a rolling mill roll thermal crown calculation method based on the rolling mill roll off-machine thermal crown and time interval, the initial thermal crown of the rolling mill roll when repeatedly on-machine is calculated, and the calculation value is used for plate shape calculation after roll replacement, so as to ensure the plate shape setting accuracy and control effect of the first strip after roll replacement. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a method flowchart of the present application;

[0031] Figure 2 is a thermal crown curve diagram based on on-machine time and off-machine time interval of the present application;

[0032] Figure 3 is a device structure diagram of the present application;

[0033] In the figure: data acquisition module 1, data calling module 2, calculation module 3, data transmission module 4. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiment of the application clearer, the technical scheme of the embodiment of the application will be clearly and completely described below in combination with the drawings in the embodiment. Obviously, the described embodiment is only a part of the embodiments of the application, but not all the embodiments of the application. Based on the embodiment of the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0035] A method for calculating the initial thermal crown of a high-speed steel rolling mill roll when repeatedly on-machine, comprising the following steps:

[0036] Step 101, when the rolling mill roll is off-machine, the rolling mill roll thermal crown based on the rolling mill roll number and the off-machine time are collected and stored in the database;

[0037] Step 102, when the roll replacement operation is performed, i.e. when the rolling mill roll is on-machine, the rolling mill roll thermal crown and off-machine time of the last off-machine time of the current rolling mill roll number are called from the database;

[0038] Step 103, it is judged whether the rolling mill roll is repeatedly on-machine. If it is not repeatedly on-machine, the thermal crown is determined to be 0. If it is repeatedly on-machine, the thermal crown of the high-speed steel rolling mill roll when repeatedly on-machine is calculated based on the determined calculation method;

[0039] Step 104, the thermal crown calculation value of the high-speed steel rolling mill roll when repeatedly on-machine is given to the plate shape model, which is used for rolling mill roll gap crown calculation.

[0040] In the step 101, if the record of the current rolling mill roll number does not exist in the database, a new record is generated for storage. If the record of the current rolling mill roll number already exists, the rolling mill roll thermal crown and off-machine time are updated.

[0041] In the step 102, if the record based on the current roll number does not exist, the roll thermal crown is set to 0 and the off-machine time is the default time.

[0042] The default time is set to 1970-01-01 00:00:00, which represents 0:00:00 on January 1, 1970.

[0043] In the step 103, the on-machine judgment method is repeated, the on-machine number in the roll information is used, the last on-machine number of the roll is initially set to 0, after each grinding, the last on-machine number of the roll is reset to 0, and after the roll is on-machine, the last on-machine number of the roll is increased by 1, so that when the roll is on-machine, the corresponding last on-machine number is judged, if the last on-machine number is 0, it is judged as non-repeated on-machine, otherwise, it is judged as repeated on-machine.

[0044] In the step 103, the determined calculation method is based on the thermal crown when the roll is off-machine last time, the off-machine time and the on-machine time this time, and is specifically expressed by a function relationship as follows:

[0045]

[0046] Wherein, C v is the thermal crown when the roll is on-machine;

[0047] C0is the thermal crown when the roll is off-machine last time;

[0048] e is the natural logarithm;

[0049] t n is the on-machine time of the roll this time;

[0050] t0is the off-machine time of the roll last time;

[0051] T is a time constant, set to T=3600, unit: minute;

[0052] f(t n ,t0) represents the time difference between the on-machine time t n of the roll this time and the off-machine time t0last time, unit: minute;

[0053] C f is a correction coefficient, the value range is 0.8-1.2, and different coefficients can be set according to the stand.

[0054] In the step 104, the calculated thermal crown when the roll is on-machine is used to compensate the roll crown when the first strip shape is set after roll replacement, so as to ensure the strip shape setting accuracy and control effect of the first strip after roll replacement, and the roll thermal crown self-learning value is used from the second strip.

[0055] The device for calculating the initial thermal crown of the high-speed steel roller in repeated on-machine includes a data acquisition module 1, a data calling module 2, a calculation module 3 and a data transmission module 4, the data acquisition module 1 is connected with the input end of the roller and the database, the data calling module 2 is connected with the output end of the database and the calculation module 3, the output end of the calculation module 3 is connected with the data transmission module 4, and the data transmission module 4 is connected with the plate shape model.

[0056] The data acquisition module 1 is used for collecting the roller thermal crown of the current roller number and the off-machine time when the roller is off-machine and storing the same into the database, the data calling module 2 is used for calling the roller thermal crown and the off-machine time of the last off-machine time of the current roller number from the database when the roller is on-machine, the calculation module 3 is used for calculating the thermal crown of the high-speed steel roller in repeated on-machine, and the data transmission module 4 is used for transmitting the thermal crown calculation value of the high-speed steel roller in repeated on-machine to the plate shape model for the roller gap crown calculation.

[0057] In actual application, firstly, the roller thermal crown of the current roller number and the off-machine time are collected when the roller is off-machine and are stored into the database, if the record of the current roller number does not exist in the database, a new record is generated and stored, otherwise, if the record of the current roller number already exists, the roller thermal crown and the off-machine time are updated, then the roller thermal crown and the off-machine time of the last off-machine time of the current roller number are called from the database when the roller is on-machine, if the record based on the current roller number does not exist, the roller thermal crown is set to 0 and the off-machine time is set to the default time, further, it is judged whether the roller is in repeated on-machine, if not, the thermal crown is determined to be 0, if yes, the thermal crown of the high-speed steel roller in repeated on-machine is calculated based on the determined calculation method, the calculation method is based on the thermal crown of the last off-machine time of the roller, the off-machine time and the on-machine time, finally, the thermal crown calculation value of the high-speed steel roller in repeated on-machine is transmitted to the plate shape model for the roller gap crown calculation, so that the plate shape setting precision and control effect of the first strip after the roller replacement are ensured.

[0058] Embodiment one

[0059] In this embodiment, a method for calculating the initial thermal crown of the high-speed steel roller in repeated on-machine is applied to the hot continuous rolling process using the high-speed steel roller, and the method comprises the following steps.

[0060] In step 101, the roller thermal crown based on the roller number and the off-machine time are collected when the roller is off-machine and are stored into the database.

[0061] Specifically, if the record of the current roller number does not exist in the database, a new record is generated and stored, otherwise, if the record of the current roller number already exists, the roller thermal crown and the off-machine time are updated.

[0062] Step 102, when the roll is put on the machine, the last time the roll is taken off the machine and the roll thermal crown and the time of taking off the machine of the current roll number are called from the database;

[0063] Specifically, if the record based on the current roll number does not exist, the roll thermal crown is set to 0 and the time of taking off the machine is the default time;

[0064] Optionally, the default time is set to 1970-01-01 00:00:00, which represents 0:00:00 on January 1, 1970;

[0065] Step 103, determining whether the roll is repeated on the machine, if not, the thermal crown is determined to be 0, and if it is repeated on the machine, the thermal crown of the high-speed steel roll is calculated based on the determined calculation method when it is repeated on the machine;

[0066] Specifically, the repeated on-machine judgment method is based on the number of times the roll is put on the machine, the last time the roll is put on the machine is initially 0, after each grinding, the last time the roll is put on the machine is reset to 0, and after the roll is put on the machine, the last time the roll is put on the machine is added by 1, so when the roll is put on the machine, the corresponding last time is determined, if the last time is 0, it is determined that it is not repeated on the machine, otherwise, it is determined that it is repeated on the machine.

[0067] Specifically, the determined calculation method is based on the thermal crown of the roll when it is last taken off the machine, the time of taking off the machine and the time of putting on the machine this time, and specifically, it is expressed by a function relationship as follows:

[0068]

[0069] Wherein, C v is the thermal crown of the roll when it is put on the machine;

[0070] C0 is the thermal crown of the roll when it is last taken off the machine;

[0071] e is the natural logarithm;

[0072] t n is the time of putting on the machine this time;

[0073] t0 is the time of taking off the machine last time;

[0074] T is a time constant, and T is set to 3600, with the unit of minute;

[0075] f(t n ,t0) represents the time difference between the time t n of putting on the machine this time and the time t0 of taking off the machine last time, with the unit of minute;

[0076] C f is a correction coefficient, and the value range is 0.8-1.2, which can be set to different coefficients according to the rack.

[0077] Step 104, the calculated value of the thermal crown of the high-speed steel roller when repeatedly put on the machine is given to the strip shape model for roller gap crown calculation;

[0078] Specifically, the calculated thermal crown C of the roller when put on the machine v For the first strip shape setting after roll replacement, the roller crown is compensated to ensure the strip shape setting accuracy and control effect of the first strip after roll replacement, and the thermal crown self-learning value of the roller is used from the second strip.

[0079] The technical scheme of the embodiment will be further described through a typical application example. On July 30, 2023, at 15:35:34, the finishing rolling was performed roll replacement, the finishing rolling roller was taken off, the roller thermal crown based on the roller number and the off-machine time were collected and stored in the database, the finishing rolling roller included the first to seventh stands, and specific information is shown in Table 1.

[0080] Table 1: Storage information of the roller off-machine

[0081]

[0082]

[0083] At 15:37:27 on July 30, 2023, when the roller was put on the machine, the roller thermal crown and off-machine time of the last off-machine time of the current roller number were called from the database. Based on the information obtained from the database, the roller number of the finishing rolling 1-7 stands is shown in Table 2.

[0084] Table 2: Information of the roller on-machine at the last off-machine time

[0085] finishing stand roll number hot crown down time 1 XTFG005 0.33249 2023-07-29 17:47:02 2 XTFG008 0.33038 2023-07-30 11:24:23 3 XTFM264 0.23537 2023-07-29 17:47:02 4 XTFM218 0.1696 2023-07-30 05:00:02 5 XTFN276 0.15116 2023-07-29 17:47:02 6 XTFM200 0.12473 2023-07-29 17:47:02 7 XTFM204 0.13065 2023-07-29 17:47:02

[0086] Further, it is judged whether the roller is repeatedly put on the machine. If it is not repeatedly put on the machine, the thermal crown is determined to be 0, and if it is repeatedly put on the machine, the thermal crown of the high-speed steel roller when repeatedly put on the machine is calculated based on the determined calculation method.

[0087] Among them, the on-machine times of the rollers except the roller number XTFG008 are 0, and the on-machine times of the other rollers are 0, which indicates that the roller number XTFG008 of the roller is repeatedly put on the machine, and the thermal crown of the high-speed steel roller when repeatedly put on the machine needs to be calculated based on the determined calculation method, and the thermal crown of the other rollers has been cooled and ground normally, and the thermal crown can be determined to be 0; for the initial thermal crown of the finishing stand 2 and the roller number XTFG008, C v The thermal crown C0 of the last off-machine time is 0.33038 mm, and the on-machine time t of the roller this time is 0.33038 mm. nThe roll last came off the mill at 15:37:27 on July 30, 2023. The roll's last off-mill time, t0, was 11:24:23 on July 30, 2023. Therefore, the roll's current on-mill time, t... n The time difference f(t) with the last time the machine stopped t0 n ,t0)=253 minutes, correction factor C f According to the finishing mill stand setup, as shown in Table 3, where C corresponds to 2 stands. f =1.0, then:

[0088]

[0089] Table 3 Correction factor C f surface

[0090]

[0091] Furthermore, the calculated thermal crown C of the rolls on the finishing mill stand 2 during rolling is... v =0.16307mm is used to compensate for the roll crown when setting the shape of the first strip after roll change, so as to ensure the accuracy and control effect of the shape setting of the first strip after roll change. From the second strip onwards, the roll thermal crown self-learning value is used. The rolls on other stands are not repeated and do not need to compensate for the roll crown.

[0092] Example 2

[0093] In this embodiment, a device for calculating the initial thermal crown of a high-speed steel roll during repeated rolling is applied to a hot continuous rolling process using high-speed steel rolls. (See also...) Figure 3 ,include:

[0094] The data acquisition module is used to collect the thermal crown of the current roll number and the roll exit time when the roll exits the mill, and store them in the database;

[0095] The data retrieval module is used to retrieve the roll thermal crown and unloading time of the current roll number from the database when the roll is loaded onto the mill.

[0096] The calculation module is used to calculate the thermal crown of high-speed steel rolls during repeated rolling.

[0097] The data transmission module is used to transmit the calculated thermal crown value of the high-speed steel roll during repeated rolling to the shape model for roll gap crown calculation.

[0098] Since the device for calculating the initial thermal crown of the high-speed steel roller when repeatedly put on the machine in the embodiment is the device used for implementing the method for calculating the initial thermal crown of the high-speed steel roller when repeatedly put on the machine in Embodiment One of the present application, the specific implementation of the device of the present embodiment and its various forms can be understood by those skilled in the art based on the method for calculating the initial thermal crown of the high-speed steel roller when repeatedly put on the machine in Embodiment One of the present application, so the system how to implement the method in the present embodiment will not be introduced in detail. As long as the device used for implementing the method for calculating the initial thermal crown of the high-speed steel roller when repeatedly put on the machine in the present embodiment is implemented by those skilled in the art, it belongs to the scope of the present application.

[0099] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A method of calculating the repeat mill initial thermal crown of a high speed steel roll characterized by The method comprises the following steps: (1) When the roll is taken off, the roll thermal crown based on the roll number and the off-machine time are collected and stored in a database; (2) When the roll changing operation is performed, i.e. when the roll is put on, the roll thermal crown and the off-machine time of the last off-machine time of the current roll number are called from the database; (3) It is judged whether the roll is repeatedly put on, if not, the thermal crown is determined to be 0, if yes, the thermal crown of the high-speed steel roll when repeatedly put on is calculated based on a determined calculation method; (4) The calculated thermal crown of the high-speed steel roll when repeatedly put on is given to a shape model for roll gap crown calculation; In the step (2), if the record based on the current roll number does not exist, the roll thermal crown is set to 0 and the off-machine time is set to a default time; In the step (3), the repeated put-on judgment method is based on the put-on times in the roll information, the initial value of the roll put-on times is 0, the roll put-on times is reset to 0 after each grinding, and the roll put-on times is added by 1 after the roll is put on, so that the corresponding put-on times is judged when the roll is put on, if the put-on times is 0, it is judged that the roll is not repeatedly put on, otherwise, it is judged that the roll is repeatedly put on; In the step (3), the determined calculation method is based on the thermal crown of the last off-machine time, the off-machine time and the current put-on time, and is specifically expressed by a function relationship as follows: ， wherein C V is the thermal crown at the roll entry; C0 is the thermal crown of the last off-machine time; e is a natural constant; t n t n t n t n t n t < t0 is the off-machine time of the last off-machine time; T is a time constant, and T=3600 is set, with the unit of minute; f(t n ,t0) represents the time difference between the current on-machine time t n and the last off-machine time t0, in minutes; C f The correction coefficient is set in the range of 0.8-1.2, and different coefficients are set according to the rack. In the step (4), the calculated thermal crown of the roll when put on is used for compensating the roll crown when the first strip shape is set after roll changing, so as to ensure the shape setting precision and control effect of the first strip after roll changing, and the roll thermal crown self-learning value is used from the second strip.

2. A method of calculating the initial thermal crown of a high speed steel roll for repeat set-up of a hot mill according to claim 1, characterized in that: In the step (1), if the record of the current roll number in the database does not exist, a new record is generated and stored, if the record of the current roll number already exists, the roll thermal crown and the off-machine time are updated.

3. A method of calculating the initial thermal crown of a high speed steel roll for repeat set-up of a hot mill according to claim 1, characterized in that: The default time is set to 1970-01-01 00:00:00, which represents 0:00:00 on January 1, 1970.

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