A method to prevent the confusion of rough rolling tracking model

Abstract

The present invention relates to a method for preventing the disorder of the rough rolling tracking model, and belongs to the technical field of hot-rolled strip production methods in the metallurgical industry. The technical solution of the present invention is: the length L of the strip after the reverse rolling of R2 is added to the length L1 of the cast steel after rolling, and the addition result is compared with the distance L2 between the center line of R2 and the HMD of the intermediate tracking of R1\R2. If (L+L1)>L2, a signal prohibiting steel entry is given to the strip to be rolled at the entrance of R1, and the rolling of R1 is suspended. After the reverse rolling of R2 is completed and the rolling is turned to again, and the HMD signal between R1 and R2 disappears, R1 is allowed to enter steel and normal rolling production is carried out. The beneficial effect of the present invention is: without changing the original hardware system layout design of the rolling line, by adding the calculation of the length of the rolled plate and strip, the strip rolling is controlled together with the hardware tracking equipment arranged online, and the model tracking problem is solved at a very low cost.

Description

Technical Field

[0001] The invention relates to a method for preventing a rough rolling tracking model from being disordered, and belongs to the technical field of hot-rolled strip steel production methods in the metallurgical industry. Background Art

[0002] The traditional production process for hot-rolled strip steel includes heating, descaling, width setting (optional), rough rolling, finishing rolling, layer cooling, and coiling. After heating in a heating furnace and removing surface oxide scale in a pre-descaler, the slab enters a width setting mill for online width adjustment (optional). The slab then enters a roughing mill for reciprocating rolling. Once the slab reaches the target thickness, it is sent to the finishing mill.

[0003] The roughing mill can be arranged as a single stand or a dual stand (the first and second stands are designated R1 and R2, respectively). Depending on the arrangement, a single stand typically uses a 5-pass or 7-pass rolling cycle, while a dual stand typically uses a 3+3 or 3+5-pass rolling cycle. The movement of the strip in different areas of the roughing mill and the rolling of different stands depend on the settings of the primary and secondary levels. The accurate execution of these settings depends on the strip tracking system along the rolling line, which is tracked by HMDs (hot metal detectors) located at various locations along the rolling line.

[0004] With the changing market competition, improving rolling line production efficiency and reducing production costs are the common goals of all steel companies. The most effective means of improving production efficiency is to increase the rolling rhythm and increase the unit weight of steel coils. To this end, companies have generally conducted research on increasing slab lengths and shortening rolling intervals. Through improvements in various rolling equipment operations, the hourly coil output has reached over 40 coils. During the efficient production process, the original strip model tracking system exposed some issues. Specifically, the increase in strip length made it difficult to properly track the strip during production. HMDs were installed before, during, and during the R1 and R2 production lines to track the strip. Under normal production conditions, strip tracking is possible. However, when increasing slab length and the rolling rhythm, the following special situation occurred: when R2 was rolling in the reverse direction and R1 was rolling in the forward direction, the head of the slab after R2 rolling exceeded the HMD before R1 / R2. This caused the tracking system to mistakenly believe that the slab rolled in R1 had arrived. As a result, the strip model rolled in R1 and the strip model rolled in R2 were connected together, causing model confusion. This made it impossible to set the production model, resulting in rolling interruption and the ejection of the intermediate slab. This problem has seriously hindered the promotion of efficient production. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preventing the disorder of the rough rolling tracking model without changing the original hardware system layout design of the rolling line. By increasing the calculation of the length of the rolled strip, the strip rolling is controlled together with the hardware tracking equipment arranged online to avoid the rolling interruption caused by the models being connected together, and the model tracking problem is solved at an extremely low cost. It can ensure the production continuity under the efficient production state, reduce production costs, and can be promoted to other areas, effectively solving the above-mentioned problems existing in the background technology.

[0006] The technical solution of the present invention is: a method for preventing the disorder of the rough rolling tracking model, comprising the following steps: the strip rolled by R2 is rolled in the reverse direction from R2 to R1. Before the start, the first-level model calculates the length L of the strip after R2 reverse rolling, and adds it to the length L1 of the rolled steel. The addition result is compared with the distance L2 between the center line of R2 and the R1\R2 intermediate tracking HMD. If (L+L1)>L2, a signal prohibiting steel entry is given to the strip to be rolled at the R1 entrance, and R1 rolling is suspended. After the reverse rolling of R2 is completed and the rolling is turned again, after the HMD signal between R1 and R2 disappears, R1 is allowed to enter steel and normal rolling production is carried out.

[0007] The calculation formula for the length of the strip after the R2 reverse rolling is as follows:

[0008] L=G / (h*b*7.85)*α

[0009] Where L is the length of the strip after R2 reverse rolling, G is the weight of the slab, h is the thickness of the strip after R2 reverse rolling, b is the width of the strip after R2 reverse rolling, and α is the thermal expansion coefficient of the strip.

[0010] The rolled steel length L1 is the distance from the strip tail to the center line of the R2 roller after rolling. The rolled steel length comes from the primary control calculation, and its length is determined by program setting.

[0011] The size of the distance L2 between the R2 center line and the R1\R2 intermediate tracking HMD depends on the installation layout of the rolling line HMD, and different production lines are matched with their own equipment layout.

[0012] The beneficial effects of the present invention are: without changing the original hardware system layout design of the rolling line, by adding the calculation of the rolled strip length, the strip rolling is controlled together with the hardware tracking equipment arranged online, so as to avoid the rolling interruption caused by the models being connected together, and solve the model tracking problem at an extremely low cost; it can ensure production continuity under efficient production conditions, reduce production costs, and can be promoted to other areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the present invention;

[0014] In the figure: 1# strip steel 1, 2# strip steel 2, R1 rolling direction 3, R2 rolling direction 4, HMD 5. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solutions and advantages of the invention implementation cases clearer, the technical solutions in the invention implementation cases will be clearly and completely described below in conjunction with the drawings in the implementation cases. Obviously, the implementation cases described are only a small part of the implementation cases of the present invention, rather than all the implementation cases. Based on the implementation cases in the present invention, all other implementation cases obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0016] A method for preventing the disorder of the rough rolling tracking model comprises the following steps: the strip steel rolled by R2 is rolled in the reverse direction from R2 to R1. Before the start, the first-level model calculates the length L of the strip steel after the reverse rolling of R2, and adds it to the length L1 of the rolled steel strip. The addition result is compared with the distance L2 between the center line of R2 and the R1\R2 intermediate tracking HMD. If (L+L1)>L2, a signal prohibiting steel feeding is given to the strip steel to be rolled at the R1 entrance, and the R1 rolling is suspended. After the reverse rolling of R2 is completed and the rolling is turned to the reverse direction again, after the HMD signal between R1 and R2 disappears, R1 is allowed to feed steel and normal rolling production is carried out.

[0017] The calculation formula for the length of the strip after the R2 reverse rolling is as follows:

[0018] L=G / (h*b*7.85)*α

[0019] Where L is the length of the strip after R2 reverse rolling, G is the weight of the slab, h is the thickness of the strip after R2 reverse rolling, b is the width of the strip after R2 reverse rolling, and α is the thermal expansion coefficient of the strip.

[0020] The rolled steel length L1 is the distance from the strip tail to the center line of the R2 roller after rolling. The rolled steel length comes from the primary control calculation, and its length is determined by program setting.

[0021] The size of the distance L2 between the R2 center line and the R1\R2 intermediate tracking HMD depends on the installation layout of the rolling line HMD, and different production lines are matched with their own equipment layout.

[0022] In practical applications:

[0023] ① Calculate the length of the strip after R2 reverse rolling at the first level. The calculation formula is as follows:

[0024] L=G / (h*b*7.85)*α

[0025] L: strip length after R2 reverse rolling;

[0026] G: Weight of the strip slab

[0027] h: strip thickness after R2 reverse rolling;

[0028] b: strip width after R2 reverse rolling;

[0029] α: thermal expansion coefficient of strip steel;

[0030] ② Rolled steel length L1

[0031] The length of the rolled steel comes from the first-level control calculation, and its length can be determined by program setting.

[0032] ③The distance L2 between the center line of R2 and the tracking HMD between R1 and R2:

[0033] The size of L2 comes from the installation layout of the rolling line HMD, and different production lines are determined according to their own equipment layout.

[0034] ④ After determining the values ​​of ① to ③, the first level performs a comparison operation and executes the following actions:

[0035] If L2>(L+L1), the slab at the R1 entrance is rolled normally;

[0036] If L2≤(L+L1), the R1 inlet generates a signal prohibiting steel feeding;

[0037] After R2 reverse rolling is completed, it switches to forward rolling and the HMD detection signal between R1\R2 disappears, the R1 steel feed prohibition signal is cancelled and normal rolling is carried out.

Claims

1. A method for preventing the disorder of the rough rolling tracking model, characterized in that The process includes the following steps: The strip steel rolled by R2 is rolled in the reverse direction from R2 to R1. Before the start, the first-level model calculates the length L of the strip steel after R2 reverse rolling, and adds it to the length L1 of the rolled steel strip. The result of the calculation is compared with the distance L2 between the center line of R2 and the HMD between R1 and R2. If (L+L1)>L2, a signal prohibiting steel feeding is given to the strip steel to be rolled at the entrance of R1, and R1 rolling is suspended. After the reverse rolling of R2 is completed and the rolling is reversed again, R1 is allowed to feed steel and normal rolling production is carried out after the HMD signal between R1 and R2 disappears. The calculation formula for the length of the strip after the R2 reverse rolling is as follows: L=G / (h*b*7.85)*α Where L is the length of the strip after R2 reverse rolling, G is the weight of the slab, h is the thickness of the strip after R2 reverse rolling, b is the width of the strip after R2 reverse rolling, and α is the thermal expansion coefficient of the strip; The rolled steel length L1 is the distance from the strip tail to the center line of the R2 roller after rolling. The rolled steel length comes from the primary control calculation, and its length is determined by program setting.

2. The method for preventing the disorder of the rough rolling tracking model according to claim 1, characterized in that: The size of the distance L2 between the R2 center line and the R1\R2 intermediate tracking HMD depends on the installation layout of the rolling line HMD, and different production lines are matched with their own equipment layout.

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