Precise control method for heavy load deviation of straight-strip hot-rolled steel bar bag

Abstract

The invention discloses a method for accurately controlling the load deviation of a straight hot-rolled steel bar package, and relates to the technical field of steel bar production. The method comprises the following steps: stably controlling the size of a product cleaning rod, namely controlling the steel temperature to be uniform and controlling the size and the shape of a key pass material to meet process requirements; fixed-length deviation control: controlling the room-temperature length allowable deviation of the steel bar after fixed-length shearing to be close to 0; and a ladle weight upper and lower limit early warning system is arranged, the ladle weight is stably controlled to fluctuate in the middle and lower limit range, and the steel temperature uniformization control mode comprises the steps that cold and hot mixed loading of the steel billet is avoided, the temperature of a uniformization section hearth is controlled to be 20-50 DEG C lower than the temperature of a heating section hearth, and a roller way heat preservation device is arranged at the steel billet discharging position. By adopting the process optimization, the negative deviation of the ladle is averagely improved by-0.5%, the average cost of per ton of steel is reduced by 5kg, the average cost of per ton of steel is reduced by 20 yuan, and remarkable benefits are created for enterprises. The hot-rolled steel bar produced through the process is uniform in size and stable in performance, the product quality is improved to a certain degree, and the market competitiveness is improved.

Description

Technical Field

[0001] The invention relates to the technical field of steel bar production, and in particular to a method for accurately controlling the weight deviation of a straight hot-rolled steel bar package. Background Art

[0002] Hot-rolled straight bars are delivered according to the fixed length and theoretical weight. The new national standard GB 1499.2-2024 stipulates that the allowable deviation of the fixed length is 0-50mm, and the weight deviation is divided into three ranges of ±5.5%, ±4.5%, and ±3.5% according to different specifications. At present, the production of straight bars adopts the negative deviation rolling process. Under the condition of ensuring that the mechanical properties, dimensional deviation and weight deviation meet the national standards, the smaller the actual weight of the steel bar is controlled, the greater the economic benefits of the enterprise.

[0003] However, in actual production, it was found that there was a large difference between the weight deviation data of sampling inspection and the weight deviation data of package weight. This was mainly due to the influence of multiple factors such as poor uniformity of product size, poor cutting line, deviation in fixed length, uneven steel temperature, weight of strapping tape, etc., which made it difficult to control the weight deviation of package weight.

[0004] Therefore, a method for accurately controlling the weight deviation of hot-rolled straight steel bar packages is proposed. Summary of the invention

[0005] The purpose of the present invention is to solve the problems mentioned in the above background technology, and provide a method for accurately controlling the weight deviation of a straight hot-rolled steel bar package.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:

[0007] A method for accurately controlling the weight deviation of a straight hot-rolled steel bar package comprises the following steps:

[0008] Stable control of product rod size: including uniform steel temperature control and key pass material size and shape control to meet process requirements;

[0009] Control of the deviation of the cut-to-length length: The room temperature length deviation of the steel bar after cutting to the cut-to-length is controlled to be close to 0;

[0010] Set up upper and lower limit warning systems for package weight to stably control package weight fluctuations within the middle and lower ranges.

[0011] Furthermore, the method of controlling the uniform temperature of the steel includes avoiding mixing of hot and cold billets, controlling the furnace temperature of the soaking section to be 20 to 50°C lower than the furnace temperature of the heating section, and setting a roller insulation device at the billet discharge position.

[0012] Furthermore, the method for avoiding mixed charging of hot and cold steel billets includes continuous hot charging or continuous cold charging of steel billets, and the temperature of the steel billets after they are taken out of the furnace and rolled is 980-1020°C.

[0013] Furthermore, the size and shape of the key pass material are observed, measured and adjusted multiple times to reduce the temperature drop of the rolled piece before slitting while ensuring a large performance margin.

[0014] Furthermore, the package weight upper and lower limit warning system includes a data acquisition module, a data processing module and a display module. The data acquisition module is used to obtain package weight data, the data processing module is used to convert the data format into a visual format and transmit it to the display module, and the display module is used to display the package weight data and draw it as a curve graph.

[0015] Furthermore, the package weight upper and lower limit warning system package also includes an alarm module, and the package weight center line is a warning signal.

[0016] The beneficial effects of the present invention are as follows:

[0017] First, the size of the product rod is stably controlled. By evenly controlling the steel temperature and ensuring that the size and shape of the key pass material meet the process requirements, the uniformity and consistency of the steel bars during processing are guaranteed, and the product quality fluctuations caused by uneven materials are reduced. Furthermore, in terms of the control of the length deviation of the fixed length, through fine adjustment, the length deviation of the steel bar after cutting can be significantly closer to the zero deviation direction, thereby greatly improving the accuracy and consistency of the steel bar length, reducing the subsequent processing problems caused by length errors, and improving the product's use efficiency and customer satisfaction. In addition, the upper and lower limit warning system of the package weight is set up to effectively stabilize the package weight fluctuation, ensure the weight consistency of the product, reduce the cost loss caused by weight deviation, and achieve efficient use of resources. By taking the above process optimization, the average negative deviation of the package is increased by -0.5%, the average reduction of 5kg per ton of steel, and the average cost reduction of 20 yuan per ton of steel, creating significant benefits for the enterprise. The hot-rolled steel bars produced by the above process are uniform in size, stable in performance, and the product quality is improved to a certain extent, which improves market competitiveness. DETAILED DESCRIPTION

[0023] A method for accurately controlling the weight deviation of a straight hot-rolled steel bar package comprises the following steps:

[0024] Stable control of product rod size: including uniform steel temperature control and key pass material size and shape control to meet process requirements;

[0025] Control of the deviation of the cut-to-length length: The room temperature length deviation of the steel bar after cutting to the cut-to-length is controlled to be close to 0;

[0026] Set up upper and lower limit warning systems for package weight to stably control package weight fluctuations within the middle and lower ranges.

[0027] First, the size of the product's wire rods is stably controlled. By evenly controlling the steel temperature and ensuring that the size and shape of the key material meet the process requirements, the uniformity and consistency of the steel bars during processing are guaranteed, reducing product quality fluctuations caused by uneven materials. Furthermore, in terms of controlling the deviation of the fixed length, through fine adjustments, the length deviation of the sheared steel bars can be significantly brought closer to the zero deviation direction, thereby greatly improving the accuracy and consistency of the steel bar length, reducing subsequent processing problems caused by length errors, and improving product efficiency and customer satisfaction. In addition, the upper and lower limit warning system for package weight is set up to effectively stabilize package weight fluctuations, ensure product weight consistency, reduce cost losses caused by weight deviations, and achieve efficient use of resources.

[0028] The method of controlling the uniform temperature of steel includes avoiding mixing of hot and cold steel billets, controlling the furnace temperature of the soaking section to be 20-50°C lower than the furnace temperature of the heating section, and setting a roller heat preservation device at the position where the steel billets are discharged from the furnace. Steel temperature is the most important factor affecting the size, and controlling the uniform and stable steel temperature is a necessary condition. The temperature of the steel billets discharged from the furnace is kept consistent by avoiding mixing of hot and cold steel billets, controlling the furnace temperature of the soaking section to make the steel billets fully uniform, and the temperature difference between the inside and outside is small. The roller heat preservation device is set to reduce the surface cooling of the steel billets.

[0029] The method of avoiding hot and cold mixed loading of steel billets includes continuous hot loading or continuous cold loading of steel billets, and the temperature of the steel billets when rolling out of the furnace is 980-1020° C. By continuous hot loading or cold loading of steel billets, the temperature of each steel billet out of the furnace is consistent and the temperature difference is small.

[0030] Observe, measure and adjust the size and shape of the key pass material for many times, and reduce the temperature drop of the rolled piece before slitting under the premise of large performance margin. By controlling the size and shape of the key pass material to meet the process requirements, create good conditions for the control of the slitting line difference in the finishing rolling process, and by reducing the temperature drop of the rolled piece before slitting, the steel temperature of the slitting multiple lines is uniform, the wear of the rolling groove is uniform, and the size shrinkage after rolling is uniform. Finally, the purpose of stable size of the straight bar and small slitting line difference is achieved.

[0031] The dimensions of H10 red blank are shown in the table below (allowable deviation ±1mm):

[0032] Specification world Mountain Bend ￠10 23.1 64.5 ￠12 42.5 43.5 ￠14 35 58.5 ￠16 47 48 ￠18 32 73 ￠20 51 52 ￠22 48.5 49.5 ￠25 42 43.5 ￠28 45.5 46.5 ￠32 42 43.5 ￠36 45.5 46.5 ￠40 52 52.5

[0033] The national standard allows a deviation of 0 to 50 mm in length. The principle of thermal expansion and contraction is used to control the allowable deviation of the room temperature length of the steel bars after cutting to be as close to 0 as possible, thereby reducing the weight of the steel bar package.

[0034] The linear expansion coefficient of carbon steel is: at 20-300℃, the linear expansion coefficient is: 12.1-13.5×10-6 / ℃, taking the center line of 12.8×10-6 / ℃, the steel temperature is about 200-300℃ during cut-to-length, so the maximum shrinkage per meter is 300*12.8×10-6×1000×1=3.84mm, and the minimum shrinkage is 200*12.8×10-6×1000×1=2.56mm; so the shrinkage range of 9 meters is 23.04-34.56mm, and the shrinkage range of 12 meters is 30.72-46.08mm; therefore, the allowable deviation of the cut-to-length length is adjusted according to the steel temperature during cut-to-length, and the allowable deviation of the cut-to-length length after shrinkage is controlled to be in the range of 0-10mm, which meets the requirements of national standards.

[0035] The upper and lower limit warning system for bale weight includes a data acquisition module, a data processing module and a display module. The data acquisition module is used to obtain bale weight data, the data processing module is used to convert the data format into a visual format and transmit it to the display module, and the display module is used to display the bale weight data and draw it as a curve. The staff monitors the curve online. During the production process, the thermal inspection worker observes the bale weight in real time according to the curve, measures the size change of the finished product in time through the bale weight change, notifies the adjustment worker to collect the material, and stably controls the bale weight to fluctuate within the middle and lower line range.

[0036] The package weight upper and lower limit warning system package also includes an alarm module, and the package weight center line is a warning signal. When the package weight is greater than the center line value, an alarm prompt is issued through the alarm module, thereby notifying the management personnel in time.

[0037] By adopting the above-mentioned process optimization, the negative deviation of the package was improved by an average of -0.5%, the average weight per ton of steel was reduced by 5kg, and the average cost per ton of steel was reduced by 20 yuan, creating significant benefits for the enterprise.

[0038] The hot-rolled steel bars produced through the above process have uniform size and stable performance, and the product quality is improved to a certain extent, thereby enhancing market competitiveness.

[0039]

[0040]

[0041] To sum up: First, the size of the product rod is stably controlled, and the uniform control of the steel temperature and the guarantee that the size and shape of the key pass material meet the process requirements ensure the uniformity and consistency of the steel bar during the processing, and reduce the product quality fluctuation caused by uneven material. Furthermore, in terms of the control of the length deviation of the fixed length, through fine adjustment, the length deviation of the steel bar after cutting can be significantly close to the zero deviation direction, thereby greatly improving the accuracy and consistency of the steel bar length, reducing the subsequent processing problems caused by the length error, and improving the product's use efficiency and customer satisfaction. In addition, the upper and lower limit warning system of the package weight is set up to effectively stabilize the package weight fluctuation, ensure the weight consistency of the product, reduce the cost loss caused by weight deviation, and achieve efficient use of resources. By taking the above process optimization, the average negative deviation of the package is increased by -0.5%, the average reduction of 5kg per ton of steel, and the average cost reduction of 20 yuan per ton of steel, creating significant benefits for the enterprise. The hot-rolled steel bars produced by the above process are uniform in size, stable in performance, and the product quality is improved to a certain extent, which improves the market competitiveness.

Claims

1. A method for accurately controlling the weight deviation of a straight hot-rolled steel bar package, characterized in that: The steps include: Stable control of product rod size: including uniform steel temperature control and key pass material size and shape control to meet process requirements; Control of the deviation of the cut-to-length length: The room temperature length deviation of the steel bar after cutting to the cut-to-length is controlled to be close to 0; Set up upper and lower limit warning systems for package weight to stably control package weight fluctuations within the middle and lower ranges.

2. According to claim 1, a method for accurately controlling the weight deviation of a straight hot-rolled steel bar package is characterized in that: The method of controlling the uniform temperature of the steel includes avoiding mixing of hot and cold billets, controlling the furnace temperature of the soaking section to be 20-50°C lower than the furnace temperature of the heating section, and setting a roller heat preservation device at the billet discharge position.

3. A method for accurately controlling the weight deviation of a straight hot-rolled steel bar package according to claim 2, characterized in that: The method for avoiding mixed charging of hot and cold steel billets includes continuous hot charging or continuous cold charging of steel billets, and the temperature of the steel billets when they are taken out of the furnace and rolled is 980-1020°C.

4. The method for accurately controlling the weight deviation of a straight hot-rolled steel bar package according to claim 1 is characterized in that: The size and shape of the material in key passes are observed, measured and adjusted multiple times to reduce the temperature drop of the rolled piece before slitting while ensuring a large performance margin.

5. The method for accurately controlling the weight deviation of a straight hot-rolled steel bar package according to claim 1, characterized in that: The package weight upper and lower limit warning system includes a data acquisition module, a data processing module and a display module. The data acquisition module is used to obtain package weight data, the data processing module is used to convert the data format into a visual format and transmit it to the display module, and the display module is used to display the package weight data and draw it into a curve graph.

6. A method for accurately controlling the weight deviation of a straight hot-rolled steel bar package according to claim 5, characterized in that: The package weight upper and lower limit warning system package also includes an alarm module, and the package weight center line is a warning signal.

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