Finish rolling area rolling technology for improving high-speed wire rod productivity

Abstract

The invention discloses a finish rolling area rolling process for improving the productivity of high-speed wire rods. The finish rolling area rolling process comprises the following steps: step 1, heating: heating a steel billet by adopting a heating furnace; secondly, rolling is conducted through a roughing mill unit; thirdly, rolling is conducted through an intermediate rolling unit; fourthly, rolling is conducted through a pre-finishing rolling unit; 5, post-cooling of the pre-finishing mill group; sixthly, rolling is conducted through a finishing mill unit; seventhly, post-cooling is conducted through a finishing mill unit; 8, spinning and looping; ninthly, controlled cooling is conducted through an air cooling line; and tenthly, collecting coils and collecting. According to the invention, a phi170 six-inch roller box of a finishing mill group is changed into a phi230 eight-inch roller box, and a roller ring is improved in a matched manner, so that the stock types and quantity of spare parts of spare rollers and roller box equipment are reduced, the spare part flow is simplified, and the working efficiency is improved; and a finishing mill area adopts a post-rolling technology, so that the rolling line speed of coiled screws and wire rods with specifications of more than phi 6 is improved, the productivity is improved, and the economic benefit is improved.

Description

Technical Field

[0001] The invention belongs to the field of long product production in the iron and steel metallurgical industry, and specifically relates to a finishing zone rolling process for improving the production capacity of high-speed wire rods. Background Art

[0002] As one of the important products in the steel industry, high-speed wire has a wide variety of products, including bearing steel, spring steel, cord steel, cold heading steel, construction steel, etc. It is widely used in automobile, machinery, metal products, construction and other industries. In recent years, the output has continued to increase, reaching 156.82 million tons in 2019, an increase of 8.9% over 2018, accounting for 15.74% of my country's crude steel output.

[0003] Typical high-speed wire rolling mills mainly include: roughing mill, intermediate rolling mill, pre-finishing mill, finishing mill. Some high-speed wires are also equipped with sizing mills after finishing mills to increase the output of high-speed wires. At present, the maximum rolling speed of ordinary high-speed wires is about 90m / s. Through the analysis of the hole system and equipment capacity of various specifications of finishing mills, without replacing the main motor, adding sizing and other equipment modifications, there is no room for improvement in rolling line speed and production capacity. Summary of the invention

[0004] The present invention provides a finishing zone rolling process for improving the production capacity of high-speed wire rods, so as to solve the defects in the prior art.

[0005] The present invention is achieved through the following technical solutions:

[0006] A finishing zone rolling process for improving the production capacity of high-speed wire rods comprises the following steps:

[0007] Step 1: Heating: Use a heating furnace to heat the steel billet;

[0008] Step 2: rolling by a roughing mill: the square billet heated in step 1 is subjected to 6 passes of short stress line roughing mill rolling;

[0009] Step 3: rolling by the intermediate rolling mill: the rolled piece in step 2 after being rolled by the rough rolling mill and cut by the flying shear I is rolled by the intermediate rolling mill for 6 passes. The temperature of the rolled piece is controlled at 900°C to 950°C before entering the intermediate rolling mill;

[0010] Step 4: Pre-finishing mill rolling: the rolled product in step 3 after being rolled by the intermediate mill and cut by the flying shear II is rolled by the pre-finishing mill for 6 passes, and the temperature of the rolled product is controlled at 950°C to 1000°C before entering the pre-finishing mill;

[0011] Step 5: cooling after the pre-finishing mill: cooling the rolled piece after the pre-finishing controlled rolling in step 4 through a post-pre-finishing water tank;

[0012] Step 6: Finishing mill group rolling: the rolled piece after the pre-finishing rolling in step 5 is cooled by the water tank and then cut by the front shear III of the finishing mill group and then rolled by the finishing mill group. The temperature of the rolled piece is controlled at 880℃~920℃ before entering the finishing mill group, and the final rolling temperature is controlled at 1000℃~1050℃;

[0013] Step 7: cooling after finishing mill: cooling the rolled piece after finishing mill control rolling in step 6 through a post-finishing water tank;

[0014] Step 8: Spinning into a coil: After the finished rolling and cooling in the water tank in step 7, the rolled piece is clamped by the front pinch roller of the spinning machine and then enters the spinning machine to spin into a coil. The spinning temperature of the spinning machine is 700℃~950℃;

[0015] Step 9: controlled cooling on the air cooling line: the wire coiled into a coil by the spinning machine in step 8 enters the air cooling line for controlled cooling;

[0016] Step 10: Coil collection: The wire coils cooled by the air cooling line in step 9 are collected at the coil collection station, cooled, bundled, weighed, labeled, and unloaded by the PF line before being put into storage.

[0017] In the above-mentioned finishing zone rolling process for improving the production capacity of high-speed wire rods, the heating temperature in step 1 is 950°C to 1200°C.

[0018] In the above-mentioned finishing zone rolling process for improving the production capacity of high-speed wire rods, in the step 2, the rough rolling unit adopts a horizontal and vertical alternating rolling method for rolling.

[0019] As described above, in a finishing zone rolling process for improving the production capacity of high-speed wire rods, the finishing rolling unit in step six replaces the original ￠170 six-inch roller ring with a ￠230 eight-inch roller ring, and adjusts the size of the replaced ￠230 roller ring to ensure stable rolling.

[0020] As described above, a finishing zone rolling process for improving the production capacity of high-speed wire rods, when the finishing mill in step six rolls φ6-φ8 specification coils and wire rods, the hole types of each finishing rolling sequence used remain unchanged, and the speed of the finishing mill is directly increased, and the rolling speed is increased by 3-5m / s. That is, when the finishing mill is rolling, the roller ring diameter increases, and the original speed rolling finishing mill speed is low, which can directly increase the rolling speed.

[0021] As described above, in a finishing zone rolling process for improving the production capacity of high-speed wire rods, the finishing mill in step six, when rolling φ10 and φ12 specification coils and wire rods, sequentially postpones the hole types of each finishing run used by 2 runs. The specific operation is: when the finishing mill rolls an empty rack, the empty rack is the rack corresponding to the first 4 passes, and the roll ring size of the postponed rack is adjusted by 0.2-0.5mm to reduce the tension between the roll rings and ensure rolling stability.

[0022] In the finishing zone rolling process for improving the production capacity of high-speed wire rods as described above, the spinning temperature of the spinning machine in step eight is 700°C to 950°C.

[0023] The advantages of the present invention are as follows: the present invention changes the ￠170 six-inch roll box of the finishing mill group into a ￠230 eight-inch roll box, improves the roll ring matching, reduces the types and quantities of spare roll and roll box equipment spare parts inventory, simplifies the spare parts process, and improves work efficiency; the finishing mill area adopts the extended rolling technology, increases the rolling line speed of coils and circles with specifications above φ6, improves productivity, and improves economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 It is a schematic diagram of the production system layout of the rolling process of the present invention;

[0026] Figure 2 It is a process pass system diagram of post-finishing rolling in the production of φ10 specification coils and strips of the finishing mill of the present invention;

[0027] Figure 3 It is a schematic diagram of the arrangement of the roll boxes and roll rings in the finishing rolling area of ​​the finishing rolling mill group of the present invention.

[0028] Figure numerals: 1. Heating furnace, 2. Rough rolling mill, 3. Flying shear I, 4. Intermediate rolling mill, 5. Flying shear II, 6. Pre-finishing rolling mill, 7. Water tank after pre-finishing rolling, 8. Flying shear III, 9. Finishing rolling mill, 10. Water tank after finishing rolling, 11. Pinch roll, 12. Laying machine. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] A finishing zone rolling process for improving the production capacity of high-speed wire rods comprises the following steps:

[0031] Step 1: Heating: Use a heating furnace to heat the steel billet;

[0032] Step 2: rolling by a roughing mill: the square billet heated in step 1 is subjected to 6 passes of short stress line roughing mill rolling;

[0033] Step 3: rolling by the intermediate rolling mill: the rolled piece in step 2 after being rolled by the rough rolling mill and cut by the flying shear I is rolled by the intermediate rolling mill for 6 passes. The temperature of the rolled piece is controlled at 900°C to 950°C before entering the intermediate rolling mill;

[0034] Step 4: Pre-finishing mill rolling: the rolled product in step 3 after being rolled by the intermediate mill and cut by the flying shear II is rolled by the pre-finishing mill for 6 passes, and the temperature of the rolled product is controlled at 950°C to 1000°C before entering the pre-finishing mill;

[0035] Step 5: cooling after the pre-finishing mill: cooling the rolled piece after the pre-finishing controlled rolling in step 4 through a post-pre-finishing water tank;

[0036] Step 6: Finishing mill group rolling: the rolled piece after the pre-finishing rolling in step 5 is cooled by the water tank and then cut by the front shear III of the finishing mill group and then rolled by the finishing mill group. The temperature of the rolled piece is controlled at 880℃~920℃ before entering the finishing mill group, and the final rolling temperature is controlled at 1000℃~1050℃;

[0037] Step 7: cooling after finishing mill: cooling the rolled piece after finishing mill control rolling in step 6 through a post-finishing water tank;

[0038] Step 8: Spinning into a coil: After the finished rolling and cooling in the water tank in step 7, the rolled piece is clamped by the front pinch roller of the spinning machine and then enters the spinning machine to spin into a coil. The spinning temperature of the spinning machine is 700℃~950℃;

[0039] Step 9: controlled cooling on the air cooling line: the wire coiled into a coil by the spinning machine in step 8 enters the air cooling line for controlled cooling;

[0040] Step 10: Coil collection: The wire coils cooled by the air cooling line in step 9 are collected at the coil collection station, cooled, bundled, weighed, labeled, and unloaded by the PF line before being put into storage.

[0041] Specifically, the heating temperature in step 1 described in this embodiment is 950°C to 1200°C.

[0042] Specifically, in step 2 of this embodiment, the rough rolling unit performs rolling by alternating horizontal and vertical rolling.

[0043] More specifically, the finishing mill in step six described in this embodiment replaces the original ￠170 six-inch roll ring with a ￠230 eight-inch roll ring, and adjusts the size of the replaced ￠230 roll ring to ensure stable rolling.

[0044] Furthermore, when the finishing mill in step six described in this embodiment rolls φ6-φ8 specification coils and wire rods, the hole types of each finishing rolling operation used remain unchanged, and the speed of the finishing mill is directly increased, thereby increasing the rolling speed by 3-5 m / s. That is, when the finishing mill is rolling, the roller ring diameter increases, and the speed of the finishing mill at the original rolling speed is low, so the rolling speed can be directly increased.

[0045] Furthermore, when the finishing mill in step six described in this embodiment rolls φ10 and φ12 specification coils and wire rods, the hole types of each finishing rolling sequence used by the finishing mill are sequentially postponed by 2 sequences. The specific operation is as follows: when the finishing mill rolls an empty rack, the empty rack is the rack corresponding to the first 4 passes, and the roller ring size of the postponed rack is adjusted by 0.2-0.5mm to reduce the tension between the roller rings and ensure rolling stability.

[0046] Furthermore, the spinning temperature of the spinning machine in step eight described in this embodiment is 700°C to 950°C.

[0047] Example

[0048] Take φ10 coil as an example, as shown below:

[0049] 1) Taking φ10 coil as an example, the original design puts 21-26 racks into use in the finishing rolling area, with 26 racks being the finished product rack and the finished product line speed being 50m / s. By delaying the pass type of the finishing rolling racks by 2 racks in sequence, putting 23-28 racks into use, with 28 racks being the finished product rack, the finished product line speed is increased from 50m / s to 55m / s after the delay process.

[0050] 2) Considering that the rolling force will increase with the increase of rolling line speed after adopting the extended rolling process, especially the original 8-inch roller ring hole type of the 22nd and 23rd frames is used in the 6-inch roller ring of the 24th and 25th frames, which has a great impact on the roller ring strength and is prone to roller ring cracking. Therefore, the original 6-inch roller box was replaced with an 8-inch roller box with adjusted speed ratio, and the 8-inch roller ring was continued to be used. Taking the 24th frame as an example, by adjusting the speed ratio of the 8-inch roller box from 0.289 to 0.393 and using the 8-inch roller ring, the rolling line speed of this frame remained unchanged, ensuring the improved roller strength.

[0051] 3) The finished product batch is changed to the corresponding batch, and the speed ratio of the finishing mill is changed according to the changed batch to ensure the stacking and pulling relationship in the finishing mill and ensure stable rolling.

[0052] The present invention reduces spare parts inventory and spare parts manager workload by changing the roller box and roller ring spare parts of the finishing mill group from two types of ￠170 six-inch and ￠230 eight-inch to only ￠230 eight-inch spare parts; adopts a gradual replacement method to complete the original ￠170 six-inch roller box to ￠230 eight-inch roller box, and the synchronous replacement of the finishing roller rings, and the transformation cost is mainly the roller box transformation cost of only about 70,000 yuan; when rolling φ6-φ8 specification coils and wire rods, the finished product line speed is increased by 3-5m / s, and when rolling φ10-φ12 specification coils and wire rods, the finished product line speed is increased by 5-10m / s, and the average monthly output is increased by about 3750 tons, achieving obvious economic benefits, thereby being able to play a role in improving production capacity.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A finishing zone rolling process for improving high-speed wire production capacity, characterized in that: The steps include: Step 1: Heating: Use a heating furnace to heat the steel billet; Step 2: rolling by a roughing mill: the square billet heated in step 1 is subjected to 6 passes of short stress line roughing mill rolling; Step 3: rolling by the intermediate rolling mill: the rolled piece in step 2 after being rolled by the rough rolling mill and cut by the flying shear I is rolled by the intermediate rolling mill for 6 passes. The temperature of the rolled piece is controlled at 900°C to 950°C before entering the intermediate rolling mill; Step 4: Pre-finishing mill rolling: the rolled product in step 3 after being rolled by the intermediate mill and cut by the flying shear II is rolled by the pre-finishing mill for 6 passes, and the temperature of the rolled product is controlled at 950°C to 1000°C before entering the pre-finishing mill; Step 5: cooling after the pre-finishing mill: cooling the rolled piece after the pre-finishing controlled rolling in step 4 through a post-pre-finishing water tank; Step 6: Finishing mill group rolling: the rolled piece after the pre-finishing rolling in step 5 is cooled by the water tank and then cut by the front shear III of the finishing mill group and then rolled by the finishing mill group. The temperature of the rolled piece is controlled at 880℃~920℃ before entering the finishing mill group, and the final rolling temperature is controlled at 1000℃~1050℃; Step 7: cooling after finishing mill: cooling the rolled piece after finishing mill control rolling in step 6 through a post-finishing water tank; Step 8: Spinning into a coil: After the finished rolling and cooling in the water tank in step 7, the rolled piece is clamped by the front pinch roller of the spinning machine and then enters the spinning machine to spin into a coil. The spinning temperature of the spinning machine is 700℃~950℃; Step 9: controlled cooling on the air cooling line: the wire coiled into a coil by the spinning machine in step 8 enters the air cooling line for controlled cooling; Step 10: Coil collection: The wire coils cooled by the air cooling line in step 9 are collected at the coil collection station, cooled, bundled, weighed, labeled, and unloaded by the PF line before being put into storage.

2. A finishing zone rolling process for improving high-speed wire rod production capacity according to claim 1, characterized in that: The heating temperature in step 1 is 950°C to 1200°C.

3. A finishing zone rolling process for improving high-speed wire production capacity according to claim 1, characterized in that: In the step 2, the rough rolling unit performs rolling by means of horizontal and vertical alternating rolling.

4. The finishing zone rolling process for improving high-speed wire production capacity according to claim 1, characterized in that: The finishing mill in step six replaces the original ￠170 six-inch roller ring with a ￠230 eight-inch roller ring, and adjusts the size of the replaced ￠230 roller ring to ensure stable rolling.

5. The finishing zone rolling process for improving high-speed wire production capacity according to claim 1, characterized in that: When the finishing mill in step six is ​​rolling φ6-φ8 specification coils and wire rods, the hole types of each finishing rolling batch used remain unchanged, and the speed of the finishing mill is directly increased, and the rolling speed is increased by 3-5m / s. That is, when the finishing mill is rolling, the roller ring diameter increases, and the original speed rolling finishing mill speed is low, which can directly increase the rolling speed.

6. A finishing zone rolling process for improving high-speed wire production capacity according to claim 1, characterized in that: When the finishing mill in step six is ​​rolling φ10 and φ12 specification coils and wire rods, the hole types of each finishing rolling sequence used by the finishing mill are sequentially postponed by 2 sequences. The specific operation is as follows: when the finishing mill is rolling an empty rack, the empty rack is the rack corresponding to the first 4 passes, and the roller ring size of the postponed rack is adjusted by 0.2-0.5mm to reduce the tension between the roller rings and ensure rolling stability.

7. A finishing zone rolling process for improving high-speed wire production capacity according to claim 1, characterized in that: The spinning temperature of the spinning machine in step eight is 700°C to 950°C.

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