A control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates

Abstract

This invention discloses a control method for effectively improving the hot charging efficiency of thin-gauge pickled steel sheets, comprising the following steps: Pre-setting two continuous casting machines for separate rolling lines, namely a 2250 line and a 1780 line; conveying molten steel to the continuous casting machines for casting, controlling multiple heats per casting to obtain slabs; conveying the slabs to the hot-rolled slab warehouse, dynamically tracking the slab cutting time; if it is predicted that the slabs can be loaded into the heating furnace within 4 hours, then the slabs are first stacked in a designated area and loaded into the heating furnace in batches; if it is predicted that the slabs will take more than 4 hours to be loaded into the heating furnace, then they are first stacked in a slow cooling zone and loaded into the heating furnace in batches within 10 hours, and a rolling plan is formulated to schedule the slab output. This method can increase the slab charging temperature, shorten the slab heating time, reduce fuel input and fuel consumption per ton of steel, improve the rolling stability of thin plates, reduce the number of scrap steel applications and the breakage rate, and lower the manufacturing cost of pickled steel sheets.

Description

Technical Field

[0001] This invention relates to the field of hot-rolled pickled steel plate technology in the metallurgical industry, specifically to a control method for effectively improving the hot delivery and charging efficiency of thin-gauge pickled steel plates. Background Technology

[0002] Pickled steel sheet is an intermediate product made from high-quality hot-rolled thin plates. After pickling to remove the oxide layer, trimming, and finishing, its surface quality and usage requirements fall between hot-rolled and cold-rolled steel sheets. It represents a relatively high-performance-price ratio compared to hot-rolled and cold-rolled steel sheets. Compared to hot-rolled steel sheets, pickled steel sheets offer several advantages: better surface quality (the removal of surface iron oxide scale improves the steel's surface quality, facilitating welding, oiling, and painting); higher dimensional accuracy (balance allows for some shape variation, reducing unevenness); improved surface finish and enhanced appearance; and reduced environmental pollution from dispersed pickling processes. Compared to cold-rolled steel sheets, pickled steel sheets offer the advantage of effectively reducing procurement costs while maintaining the required surface quality. They are widely used in automotive parts, light industrial appliances, highway guardrails, and other applications.

[0003] At present, as hot-rolled plates expand to thinner specifications, the production demand for thin-specification pickled plates is also gradually increasing. However, due to the high surface quality requirements of thin-specification pickled plates, especially those with a finished thickness of less than 2.1 mm and a tensile strength of ≤590 MPa, the overall production is quite difficult. Common problems include high rolling difficulty, insufficient transition material, and inability to effectively and quickly load the furnace for production, leading to slab cooling. At the same time, the cold slabs may not be fully heated, resulting in scrap steel or breakage. As a result, the production of thin-specification pickled plates suffers from low production efficiency, poor production stability, low finished product quality, and high production costs. Summary of the Invention

[0004] The purpose of this invention is to provide a control method that effectively improves the hot conveying and hot loading efficiency of thin-gauge pickled plates, thereby improving production stability, production efficiency and product yield, and reducing enterprise production costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates includes the following steps:

[0007] S1: Two continuous casting machines are pre-set to produce rolling lines, namely the 2250 line and the 1780 line. The 2250 line is set to prioritize rolling non-high-strength pickled thin plates, and the 1780 line is set to prioritize rolling high-strength pickled thin plates.

[0008] S2: The molten steel is transported to the continuous casting machine for casting. Multiple furnaces are tapped in a single casting to obtain slabs.

[0009] S3: Transport the slab to the hot-rolled slab warehouse and dynamically track the slab cutting time. If it is predicted that the slab can be loaded into the heating furnace within 4 hours, then proceed to step S5. If it is predicted that the slab will take more than 4 hours to be loaded into the heating furnace, then proceed to step S4.

[0010] S4: After entering the hot-rolled slab warehouse, the slabs are piled up in the slow cooling zone and step S5 is executed within 10 hours.

[0011] S5: Based on the slab specifications, process, and the number of continuously rolled slabs in the actual production line, divide the slabs into batches and load them into the heating furnace in sequence. At the same time, formulate a rolling plan to allocate and arrange the steel output of the slabs.

[0012] S6: Based on the slab output, formulate a rolling plan. If the multi-heat slabs obtained in step S2 consist of 2 heats of thin slabs and 3 heats of non-thin slabs, or if the number of steel outputs in step S2 reaches 4 or more, then directly roll the slabs. Otherwise, divert the slabs to the 2250 production line and the 1780 production line for rolling. The rolling thickness of the thin slabs is less than or equal to 2.1 mm, and the rolling thickness of the non-thin slabs is greater than 2.1 mm.

[0013] Furthermore, in step S1, both the 2250 production line and the 1780 production line are linear material flow production lines, and each is equipped with two continuous casting machines.

[0014] Furthermore, in step S1, the 1780 production line is equipped with a hot roll box device.

[0015] Furthermore, in step S4, the slow cooling zone is equipped with a heat-insulating pit or heat-insulating furnace for centrally stacking slabs.

[0016] Furthermore, in step S5, the current batch of slabs is loaded into the heating furnace, while the remaining batches of slabs are stacked in the hot-rolled slab warehouse, waiting to be loaded into the heating furnace.

[0017] Furthermore, the specifications of the pickled sheet are as follows: the finished thickness is less than 2.1 mm, and the tensile strength is less than or equal to 590 MPa.

[0018] The beneficial effects of this invention are:

[0019] 1. This method uses casting, hot delivery, stacking, hot charging, and rolling as the process steps, organically combining the steelmaking process with the hot rolling process. This reduces the production difficulty of thin-gauge pickled plates, while achieving the shortest slab logistics division of production lines, increasing the number of continuous rolling blocks of thin-gauge pickled plates, which is conducive to improving the production stability and efficiency of thin-gauge pickled plates.

[0020] 2. Starting from steelmaking and casting, the plan is to adopt a steelmaking mode of 2 heats of thin slab billets + 3 heats of non-thin slab billets to reduce the number of heats of thin slab casting in a single batch and effectively ensure the stable production of thin slabs on a single production line.

[0021] 3. By centralizing stacking and diverting production lines, the efficiency of hot charging and hot delivery can be improved, ensuring that the slab charging temperature can be maintained above 400℃. This increases the average charging temperature of the slab, effectively reduces slab temperature drop, reduces fuel input for slab heating, and lowers fuel consumption per ton of steel. Consequently, the slab heating time is shortened, the number of scrap steel generation times is reduced, and the breakage rate is lowered. This significantly improves the rolling stability of thin plates, increases product production efficiency and yield, and reduces enterprise production costs. Detailed Implementation

[0022] The technical solutions in the embodiments of the present invention will be described below.

[0023] A control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates includes the following steps:

[0024] S1: Two continuous casting machines are pre-set to produce rolling lines, namely the 2250 line and the 1780 line. The 2250 line is set to prioritize rolling non-high-strength pickled thin plates, and the 1780 line is set to prioritize rolling high-strength pickled thin plates.

[0025] S2: The molten steel is transported to the continuous casting machine for casting. Multiple furnaces are tapped in a single casting to obtain slabs.

[0026] S3: Transport the slab to the hot-rolled slab warehouse and dynamically track the slab cutting time. If it is predicted that the slab can be loaded into the heating furnace within 4 hours, then proceed to step S5. If it is predicted that the slab will take more than 4 hours to be loaded into the heating furnace, then proceed to step S4.

[0027] S4: After entering the hot-rolled slab warehouse, the slabs are piled up in the slow cooling zone and step S5 is executed within 10 hours.

[0028] S5: Based on the slab specifications, process, and the number of continuously rolled slabs in the actual production line, divide the slabs into batches and load them into the heating furnace in sequence. At the same time, formulate a rolling plan to allocate and arrange the steel output of the slabs.

[0029] S6: Based on the slab output, formulate a rolling plan. If the multi-heat slabs obtained in step S2 consist of 2 heats of thin slabs and 3 heats of non-thin slabs, or if the number of steel outputs in step S2 reaches 4 or more, then directly roll the slabs. Otherwise, divert the slabs to the 2250 production line and the 1780 production line for rolling. The rolling thickness of the thin slabs is less than or equal to 2.1 mm, and the rolling thickness of the non-thin slabs is greater than 2.1 mm.

[0030] Furthermore, in step S1, both the 2250 production line and the 1780 production line are linear material flow production lines, and each is equipped with two continuous casting machines.

[0031] Furthermore, in step S1, the 1780 production line is equipped with a hot roll box device.

[0032] Furthermore, in step S4, the slow cooling zone is equipped with a heat-insulating pit or heat-insulating furnace for centrally stacking slabs.

[0033] Furthermore, in step S5, the current batch of slabs is first loaded into the heating furnace, while the remaining batches of slabs are stacked together in the hot-rolled slab warehouse, waiting to be loaded into the heating furnace.

[0034] Furthermore, the specifications of the pickled sheet are as follows: the finished thickness is less than 2.1 mm, and the tensile strength is less than or equal to 590 MPa.

[0035] It should be noted that in step S1, the 2250 production line can continuously roll 30 thin plate slabs with a thickness of less than 2.1 mm and 15 thin plate slabs with a thickness of less than 1.5 mm; the 1780 production line can continuously roll 35 thin plate slabs with a thickness of less than 2.1 mm and 20 thin plate slabs with a thickness of less than 1.5 mm.

[0036] It should be noted that in step S2, this method requires controlling multiple heats of steel in a single casting. In actual production, the number of heats and specifications of slabs are unstable. Based on the actual production situation of slabs, the slabs are rolled separately, which can effectively ensure the stable production of the production line, reduce rolling production costs, and ensure the rolling quality of slabs.

[0037] It should be noted that in step S4, the heat preservation pit and heat preservation furnace can achieve a better slow cooling effect and prevent the temperature of the slab from dropping too quickly.

[0038] It should be noted that in step S5, the slabs are fed into the heating furnace in batches, which can ensure the hot charging quality of the slabs and facilitate the subsequent uniform rolling process. The slabs waiting to be loaded into the furnace can be stacked in a concentrated manner at the stacking position to achieve slow cooling, and at the same time, it is convenient to load them into the furnace nearby.

[0039] It is important to understand that this method uses casting, hot delivery, stacking, hot charging, and rolling as the process steps, organically combining the steelmaking process with the hot rolling process. This reduces the production difficulty of thin-gauge pickled plates, while achieving the shortest slab logistics division of production lines, increasing the number of continuously rolled thin-gauge pickled plates, and thus improving the production stability and efficiency of thin-gauge pickled plates.

[0040] It is important to understand that, starting from steelmaking and casting, the plan is to adopt a steelmaking mode of 2 heats of thin slab billets + 3 heats of non-thin slab billets, reducing the number of heats of thin slab casting in a single batch and effectively ensuring the stable production of thin slabs on a single production line.

[0041] It is important to understand that this method improves the efficiency of hot charging and conveying by centralized stacking and production line diversion, so that the slab charging temperature can be maintained above 400℃, increasing the average charging temperature of the slab, effectively reducing the temperature drop of the slab, reducing the fuel input for raising the slab temperature from room temperature to 1230℃ in the heating furnace, reducing fuel consumption per ton of steel, thereby shortening the slab heating time, reducing the number of scrap steel generation, reducing the breakage rate, and thus significantly improving the rolling stability of thin plates, increasing product production efficiency and yield, and reducing enterprise production costs.

Claims

1. A control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates, characterized in that: Includes the following steps: S1: Two continuous casting machines are pre-set to produce rolling lines, namely the 2250 line and the 1780 line. The 2250 line is set to prioritize rolling non-high-strength pickled thin plates, and the 1780 line is set to prioritize rolling high-strength pickled thin plates. S2: The molten steel is transported to the continuous casting machine for casting. Multiple furnaces are tapped in a single casting to obtain slabs. S3: Transport the slab to the hot-rolled slab warehouse and dynamically track the slab cutting time. If it is predicted that the slab can be loaded into the heating furnace within 4 hours, then proceed to step S5. If it is predicted that the slab will take more than 4 hours to be loaded into the heating furnace, then proceed to step S4. S4: After entering the hot-rolled slab warehouse, the slabs are piled up in the slow cooling zone and step S5 is executed within 10 hours. S5: Based on the slab specifications, process, and the number of continuously rolled slabs in the actual production line, divide the slabs into batches and load them into the heating furnace in sequence. At the same time, formulate a rolling plan to allocate and arrange the steel output of the slabs. S6: Based on the slab output, formulate a rolling plan. If the multi-heat slabs obtained in step S2 consist of 2 heats of thin slabs and 3 heats of non-thin slabs, or if the number of steel outputs in step S2 reaches 4 or more, then directly roll the slabs. Otherwise, divert the slabs to the 2250 production line and the 1780 production line for rolling. The rolling thickness of the thin slabs is less than or equal to 2.1 mm, and the rolling thickness of the non-thin slabs is greater than 2.1 mm.

2. The control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates according to claim 1, characterized in that: In step S1, both the 2250 production line and the 1780 production line are linear material flow production lines, and each is equipped with two continuous casting machines.

3. The control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates according to claim 1 or 2, characterized in that: In step S1, the 1780 production line is equipped with a hot roll box device.

4. The control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates according to claim 1, characterized in that: In step S4, the slow cooling zone is equipped with a heat-insulating pit or heat-insulating furnace for centrally stacking slabs.

5. The control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates according to claim 1, characterized in that: In step S5, the current batch of slabs is first loaded into the heating furnace, while the remaining batches of slabs are stacked in the hot-rolled slab warehouse, waiting to be loaded into the heating furnace.

6. The control method for effectively improving the hot delivery and hot loading efficiency of thin-gauge pickled plates according to claim 1, characterized in that: The specifications of the pickled sheet are as follows: the finished thickness is less than 2.1 mm and the tensile strength is less than or equal to 590 MPa.