An emergency method for a pusher failure during rolling

Abstract

The present invention discloses an emergency method for the event of a pusher failure during the rolling process of a rolling mill, comprising the following steps: Step S1: maximizing the opening of the failed pusher and switching the pusher control mode to OFF; Step S2: closing the hydraulic valves of a pair of pushers on the failed side and placing a maintenance sign on the valves to prohibit opening the valves; Step S3: modifying the steel transfer strategy on the input control interface to force steel transfer on the side with the unfaulted pusher; Step S4: modifying the background control so that the rolling mill defaults to a state where the failed pusher is always ready. When a pusher fails during the operation of the rolling mill, the present method can be used to quickly set the relevant parameters of the rolling mill and shut down the failed pusher, ensuring that the failed pusher does not affect the continued operation of the rolling mill and does not affect the maintenance of the failed pusher. This can significantly improve the operating efficiency of the rolling mill and greatly reduce the losses caused by the pusher failure.

Description

Technical Field

[0001] The invention relates to the technical field of emergency methods for rolling mill pusher failure, in particular to an emergency method for a pusher failure occurring during the rolling process of a rolling mill. Background Art

[0002] Most production methods for wide and heavy plate roughing mills are as follows: 1) The slab is heated, passes through a descaling box, and is centered on a pusher before arriving at the rolling mill. It is then rolled longitudinally in one pass. The slab is then turned 90 degrees, centered on a pusher, and widened to the target width by transverse rolling. The slab is then turned 90 degrees, centered on a pusher, and rolled longitudinally to the target thickness. 2) The slab is heated, passes through a descaling box, and is centered on a pusher before arriving at the rolling mill. It is then widened to the target width by transverse rolling. The slab is then turned 90 degrees, centered on a pusher, and rolled longitudinally to the target thickness. 3) The slab is heated, passes through a descaling box, and is centered on a pusher before arriving at the rolling mill. It is then rolled longitudinally to the target thickness.

[0003] In a wide and thick plate rolling mill, equipment operating rate is an important indicator. The higher the equipment operating rate, the higher the output and the better the benefits. Equipment failure is an important factor affecting equipment operating rate. For a rolling mill in a rolling mill, the pusher is an important steel plate centering device and plays an important role. Generally, when the pusher fails, it is impossible to center the steel plate. The steel plate is tilted when it reaches the rolling mill, which does not meet the rolling conditions. The mill can only be shut down for unplanned maintenance of the pusher. The maintenance time ranges from tens of minutes to more than ten hours, which has a significant impact and loss on the rolling mill. In order to reduce losses and improve operating rate, an emergency method for pusher failure during the rolling process of the rolling mill is proposed. Summary of the Invention

[0004] The purpose of the present invention is to solve the above problems and provide an emergency method for the occurrence of a pusher failure during the rolling process of a rolling mill.

[0005] The specific solution of the present invention is: an emergency method for a pusher failure during the rolling process of a rolling mill, comprising the following steps:

[0006] Step S1: Open the faulty stretcher to the maximum and switch the stretcher control mode to OFF;

[0007] Step S2: Close the hydraulic valves of the pair of stretchers on the faulty side, and hang a maintenance sign on the valves to prohibit opening the valves;

[0008] Step S3: On the input control interface, modify the steel transfer strategy to force steel transfer on the side of the pusher without faults;

[0009] Step S4: Modify the background control so that the rolling mill defaults to the state where the fault push bed is always ready.

[0010] Furthermore, in step S4, a one-button forced button is developed and produced. When a push bed fails, other preparation conditions are completed and the corresponding button is selected to force the faulty push bed conditions so that the faulty push bed meets the conditions for rolling steel, simplifying the operation and saving time.

[0011] Furthermore, the opening of the push bed at the rolling outlet is set at 1200 mm.

[0012] Furthermore, the steel rolling bite speed and rolling speed are reduced.

[0013] The present invention has the following beneficial effects: when a push bed fails during the operation of the rolling mill, the present method can be used to set the relevant parameters of the rolling mill in a short time, and shut down the failed push bed, so that the failed push bed does not affect the continued operation of the rolling mill, and does not affect the maintenance of the failed push bed, thereby greatly improving the working efficiency of the rolling mill and greatly reducing the losses caused by the push bed failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the emergency treatment process of the present invention. DETAILED DESCRIPTION

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0016] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0017] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0018] A rolling mill is a device used to carry out the metal rolling process, broadly referring to the equipment that completes the entire process of rolling production. Depending on the number of rollers, rolling mills can be divided into two-roll, four-roll, six-roll, eight-roll, twelve-roll, and eighteen-roll types. Furthermore, depending on the arrangement of the rollers, rolling mills can be divided into "L," "T," "F," "Z," and "S" types. Conventional rolling mills primarily consist of rollers, a stand, a roll gap adjustment device, a roll temperature control device, a transmission, a lubrication system, a control system, and a roll removal device. Precision rolling mills, on the other hand, possess the main components and devices of conventional rolling mills, but also incorporate devices designed to ensure rolling accuracy.

[0019] 1) The function of the roughing mill pusher

[0020] The process of pushing the incoming slab to the centerline of the rolling mill is to align the slab so that it is in the center of the mill and square when rolling begins. The slab and the rollers are at a 90° angle to ensure the stability of the rolling process and the rectangularity of the rolled plate. The pusher alignment is generally used in the first pass of each stage of rolling a slab. The roughing mill rolling process is usually divided into three stages: the first stage is preforming, the second stage is widening, and the third stage is longitudinal rolling to the target thickness.

[0021] The first stage is the centering of the incoming material, after which the first preforming rolling is carried out.

[0022] The second stage is the widening stage. After the steel is turned, the slab is centered and the slab is turned 90 degrees and pushed onto the bed for centering, and then widening rolling is performed.

[0023] In the third stage, longitudinal rolling, after widening is completed, the steel is turned 90 degrees and pushed into the center of the bed, and then longitudinally rolled to the target thickness.

[0024] 2) Problems to be solved after the stretcher fails

[0025] The roughing mill has two pairs of pushers, one for the inlet and one for the outlet. If one pusher fails and becomes unusable, alignment becomes impossible, causing the steel plate to be misaligned or the slab and rolls to be at a different angle than 90°. This leads to unstable rolling, damage to the equipment, and deformation of the slab, which cannot meet production requirements. Ensuring the position and angle of the slab during rolling is crucial.

[0026] ① Push bed safety and rolling safety

[0027] Pusher safety: During the rolling process, the pusher automatically adjusts to changes in the rolling width and rolling direction. If a pusher malfunctions, its position becomes uncontrollable, creating a significant risk of collision with the rolling slab. Operators' habitual operation may lead to improper operation during a malfunction, potentially damaging the equipment.

[0028] Rolling safety: After the pusher fails, it cannot be centered, the slab is not in the correct position, the steel plate cannot be rolled, and during the rolling process, the slab runs obliquely and hits the pusher.

[0029] ②How to perform rolling after a push bed fails

[0030] When one side of the push bed fails, the pusher cannot move normally and cannot reach the set position of the secondary calculation. The secondary system of the rolling mill will think that the push bed is not ready and will not perform rolling.

[0031] ③Slab centering problem after one side pusher failure

[0032] When one side of the push bed fails and needs to be aligned, the alignment operation cannot be completed and the steel plate cannot be rolled; during the rolling process, the slab is not restricted by the push bed and there is a risk of it running tilted and hitting the push bed on the other side.

[0033] ④ Rolling stability after one side pusher failure

[0034] Under normal circumstances, the rolling speed is fast. Due to the speed difference of the rollers, the collision between the slab and the rollers, etc., the slab may run inclination to varying degrees during the rolling process. Without the restriction of the push bed during the rolling process, the running may become serious and the rolling stability will be reduced.

[0035] Please refer to Figure 1 , an emergency method for a pusher failure during a rolling mill rolling process, comprising the following steps:

[0036] Step S1: Open the faulty stretcher to the maximum and switch the stretcher control mode to OFF;

[0037] Step S2: Close the hydraulic valves of the pair of stretchers on the faulty side, and hang a maintenance sign on the valves to prohibit opening the valves;

[0038] Step S3: On the input control interface, modify the steel transfer strategy to force steel transfer on the side of the pusher without faults;

[0039] Step S4: Modify the background control so that the rolling mill defaults to the state where the fault push bed is always ready.

[0040] In this embodiment, in step S4, a one-button forced button is developed and manufactured. When a push bed fails, other preparation conditions are completed and the corresponding button is selected to force the faulty push bed conditions so that the faulty push bed meets the conditions for rolling steel, simplifying the operation and saving time.

[0041] In this embodiment, the opening of the push bed at the rolling outlet is set at 1200 mm.

[0042] In this embodiment, the steel rolling biting speed and the rolling speed are reduced.

[0043] The present invention has the following beneficial effects: when a push bed fails during the operation of the rolling mill, the present method can be used to set the relevant parameters of the rolling mill in a short time, and shut down the failed push bed, so that the failed push bed does not affect the continued operation of the rolling mill, and does not affect the maintenance of the failed push bed, thereby greatly improving the working efficiency of the rolling mill and greatly reducing the losses caused by the push bed failure.

[0044] First implementation of a new program

[0045] Failure of the pusher at the inlet of the roughing mill:

[0046] Emergency preparation took 35 minutes, including notifying electrical personnel, opening and closing valves, forcing conditions, modifying control strategies, and modifying rolling parameters.

[0047] The steel rolling was smooth. The pusher was overhauled for 6 hours and 50 minutes, and the single-side pusher was in production for 6 hours and 15 minutes. 138 blocks and 1,750 tons were rolled.

[0048] The inlet pusher of the roughing mill broke down, and compared with the previous time, the company utilized the maintenance time to produce 6.25 hours, producing 1,750 tons more.

[0049] Second implementation of the new plan

[0050] Failure of the pusher at the inlet of the roughing mill:

[0051] Emergency preparations take 10 minutes, including notifying inspection personnel, opening the bed, closing valves, one-button force, modifying control strategies, and modifying rolling parameters.

[0052] The steel rolling was smooth. The pusher was overhauled for 6 hours and 20 minutes, and the single-side pusher was in production for 6 hours and 10 minutes. 135 blocks and 1,727 tons were rolled.

[0053] The inlet pusher of the roughing mill broke down, and compared with the previous time, the company utilized the maintenance time to produce 6.16 hours, producing 1,727 tons more.

Claims

1. An emergency method for a pusher failure during rolling mill rolling, characterized in that : It includes the following steps: Step S1: Open the faulty stretcher to the maximum and switch the stretcher control mode to OFF; Step S2: Close the hydraulic valves of the pair of stretchers on the faulty side, and hang a maintenance sign on the valves to prohibit opening the valves; Step S3: On the input control interface, modify the steel transfer strategy to force steel transfer on the side of the pusher without faults; Step S4: Modify the background control so that the rolling mill defaults to the state where the fault push bed is always ready.

2. The emergency method for a rolling mill in case of a pusher failure during rolling according to claim 1, characterized in that: In step S4, a one-button forced button is developed and manufactured. When a push bed fails, other preparation conditions are completed and the corresponding button is selected to force the faulty push bed conditions so that the faulty push bed meets the conditions for rolling steel.

3. The emergency method for a pusher failure during rolling of a rolling mill according to claim 2, characterized in that: Set the opening of the rolling mill pusher at 1200 mm.

4. The emergency method for a pusher failure during rolling of a rolling mill according to claim 1, characterized in that: Reduce the steel rolling biting speed and rolling speed.

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