Production line and method for shortening non-cold section of high-speed finished product under TMCP (Thermal Mechanical Control Processing) process

Abstract

The invention relates to the technical field of steel production, in particular to a production line and method for shortening a non-cold section of a high-speed finished product under a TMCP process. The production line comprises a feeding rack, the feeding rack is connected with a feeding port of a heating furnace through a furnace inlet roller way, a discharging port of the heating furnace is connected with a roughing mill unit, a first flying shear, an intermediate mill unit, a second flying shear, a pre-finishing mill unit and a module mill unit through a furnace outlet roller way, and a discharging port of the module mill unit is sequentially connected with a first pinch roll, a third flying shear and a finishing mill unit. And a discharge hole of the finishing mill group is sequentially connected with a second pinch roll, a fourth flying shear, a mini rolling mill group, a third pinch roll, a fourth pinch roll, a front pinch roll of a silking machine and the silking machine. According to the invention, the head non-cold section of a high-speed wire product produced by adopting the TMCP process can be sheared at least, and the length of the head non-cold section is shortened from 50-60 meters to 3-10 meters.

Description

Technical Field

[0001] The invention relates to the technical field of steel production, and in particular to a production line and a method for shortening a non-cooling section of a finished product through a high-speed line under a TMCP process. Background Art

[0002] High-speed wire, short for high-speed wire rod, is a wire rod rolled by a high-speed no-twist rolling mill. The diameter of high-speed wire is usually between 5.5 and 14 mm, and the weight of each wire (coil) is between 1.8 and 2.7 tons. Compared with ordinary wire (wire rod rolled by ordinary rolling mill), high-speed wire has higher dimensional tolerance accuracy and better mechanical properties.

[0003] At present, most domestic high-speed wires use the TMCP process to produce rebar. The TMCP process requires water cooling of steel during and after rolling. Because the rolling specifications of high-speed wire are small and the finished product speed is fast, in order to avoid steel piling up in the water tank due to water resistance, a head non-cooling section is set in each water tank, especially the water tank after the finished rolling mill. After the steel is clamped by the front pinch rollers of the laying machine, the cooling water in the water tank is turned on, and the steel will have a certain length of head non-cooling section. The length of the head non-cooling section of the high-speed wire depends on the distance from the finished rolling mill to the pinch rollers. Most high-speed wire finished rolling mills are more than 50 meters away from the pinch rollers of the laying machine, resulting in a head non-cooling section of more than 50 meters.

[0004] The uncooled section at the head of the high-speed wire has high steel temperature and steel performance is lower than the standard requirements. In order to ensure the quality of the product, the uncooled section at the head needs to be manually cut off, resulting in the yield rate of high-speed wire rebar produced by the TMCP process being more than 0.5% lower than that of the conventional process. Summary of the invention

[0005] In view of the technical problem that the head non-cooling section of high-speed wire products produced by TMCP process is too long, the present invention provides a production line and method for shortening the non-cooling section of finished products of high-speed wire under TMCP process.

[0006] The technical solution of the present invention is as follows: In a first aspect, the present invention provides a production line for shortening the non-cold section of a finished product of a high-speed line under a TMCP process, comprising a loading platform, the loading platform is connected to the feeding port of a heating furnace through an inlet roller, the discharging port of the heating furnace is connected to the feeding port of a rough rolling unit through a discharging roller, the discharging port of the rough rolling unit is sequentially connected to a 1# flying shear and an intermediate rolling unit, the discharging port of the intermediate rolling unit is sequentially connected to a 2# flying shear, a pre-finishing rolling unit and a module rolling unit, the discharging port of the module rolling unit is sequentially connected to a 1# pinch roller, a 3# flying shear and a finishing rolling unit, the discharging port of the finishing rolling unit is sequentially connected to a 2# pinch roller, a 4# flying shear and a mini rolling unit, the discharging port of the mini rolling unit is sequentially connected to a 3# pinch roller, a 4# pinch roller, a front pinch roller of a laying head and a laying head; There are 1# water tank and 2# water tank between the discharge port of the modular rolling mill and the 1# pinch roller; There are water tanks No. 3, No. 4, and No. 5 between the discharge port of the finishing mill and the No. 4 flying shear. There is a water tank No. 6 between the No. 3 pinch roll and the No. 4 pinch roll, and there are water tanks No. 7 and No. 8 between the No. 4 pinch roll and the pinch roll before the coiler.

[0007] Furthermore, a No. 3 pinch roll is configured 1 meter away from the discharge port of the mini-mill.

[0008] Furthermore, the roughing mill train includes seven roughing mills, the intermediate mill train includes six intermediate mills, the pre-finishing mill train includes four pre-finishing mills, and the modular mill train includes two modular mills.

[0009] Furthermore, the discharge port of the coiler is connected to the Stelmor line and the coiling reel in sequence.

[0010] In a second aspect, the present invention provides a method for shortening the non-cooling section of finished products in high-speed wire under the TMCP process, including the following steps: (1) Heating the continuous casting billet of steel in a heating furnace, with the temperature of the first heating section being 760 - 860 °C, the temperature of the second heating section being 960 - 1040 °C, and the soaking section temperature being 970 - 1030 °C. The steel billet is heated in the heating furnace to 910 - 950 °C, and after the heating time is ≥ 1.5 hours, it is discharged from the furnace; (2) After the steel billet is rolled by the roughing mill, intermediate mill, pre-finishing mill, and modular mill, the steel temperature rises from 910 - 950 °C to 1020 - 1050 °C, and then is cooled by water tanks No. 1 and No. 2, and the steel temperature drops to 880 - 950 °C; (3) The steel after being sheared by the No. 3 flying shear enters the finishing mill for rolling, the steel temperature rises from 880 - 950 °C to 980 - 1050 °C, and then is cooled by water tanks No. 3, No. 4, and No. 5, and the steel temperature drops to 780 - 830 °C; (4) The steel after being sheared by the No. 4 flying shear enters the mini-mill for rolling, the steel temperature rises from 780 - 830 °C to 860 - 910 °C, and then is clamped by the No. 3 pinch roll, cooled by the No. 6 water tank, clamped by the No. 4 pinch roll, cooled by water tanks No. 7 and No. 8, and clamped by the pinch roll before the coiler and then coiled, and the steel temperature drops to 780 - 810 °C.

[0011] Furthermore, the continuous casting billet of steel is heated in the heating furnace by cold charging or hot charging.

[0012] Furthermore, water tanks No. 1 and No. 2 are in the normally open mode.

[0013] Furthermore, water tanks No. 3, No. 4, and No. 5 are in the normally open mode.

[0014] Furthermore, water tanks No. 6, No. 7, and No. 8 are in the normally open mode.

[0015] Furthermore, after being collected by the collection reel, the product is transferred to the vertical reel rack for placement, and then transported to the P&F transport line by the reel transport trolley.

[0016] The beneficial effects of the present invention are: In order to avoid steel piling in the area between the mini rolling mill and the laying head due to high speed and large water penetration resistance, the present invention configures multiple pinch rollers in this area to achieve the shortest setting of the non-cooling section length (0 meter).

[0017] The present invention can achieve minimum shearing of the head non-cooling section of the high-wire product produced by the TMCP process through precise control of the start rolling temperature, the temperature entering the finishing mill, the temperature entering the mini-mill and the spinning temperature, and the application of the normally open mode of the rear water tanks of the pre-finishing mill (1# water tank, 2# water tank) and the rear water tanks of the finishing mill (3# water tank, 4# water tank and 5# water tank), and the setting of the shortest length of the non-cooling section of the rear water tank of the mini-mill. The length of the head non-cooling section is shortened from 50 to 60 meters to about 3 to 10 meters, and the yield rate is increased by more than 0.5% compared with the yield rate of the high-wire with general configuration of the same process, and the processing cost is reduced by more than 2.5 yuan / ton, which greatly reduces the labor intensity of the workers who cut the head and tail. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a process flow chart of producing high-line products in a production line according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only 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 should fall within the scope of protection of the present invention.

[0020] Example 1 A production line for shortening the non-cold section of finished products under the TMCP process, comprising a loading platform, the loading platform is connected to the feeding port of a heating furnace through a furnace entry roller, the discharging port of the heating furnace is connected to the feeding port of a rough rolling unit through a furnace exit roller, the rough rolling unit comprises seven rough rolling mills, the discharging port of the rough rolling unit is sequentially connected to a No. 1 flying shear and an intermediate rolling unit, the intermediate rolling unit comprises six intermediate rolling mills, the discharging port of the intermediate rolling unit is sequentially connected to a No. 2 flying shear, a pre-finishing rolling unit and a module rolling unit, the pre-finishing rolling unit comprises four pre-finishing rolling mills, the module rolling unit comprises two module rolling mills, the discharging port of the module rolling unit is sequentially connected to a No. 1 pinch roller, a No. 3 flying shear and a finishing rolling unit , 1# water tank and 2# water tank are arranged between the discharge port of the module rolling mill group and the 1# pinch roller, the discharge port of the finishing mill group is connected with the 2# pinch roller, 4# flying shear and mini rolling mill group in sequence, 3# water tank, 4# water tank and 5# water tank are arranged between the discharge port of the finishing mill group and the 4# flying shear, 3# pinch roller is arranged 1 meter away from the discharge port of the mini rolling mill group, the discharge port of the 3# pinch roller is connected with the 4# pinch roller, the front pinch roller of the spinning machine and the spinning machine in sequence, 6# water tank is arranged between the 3# pinch roller and the 4# pinch roller, 7# water tank and 8# water tank are arranged between the 4# pinch roller and the front pinch roller of the spinning machine, the discharge port of the spinning machine is connected with the Stelmore line and the collecting drum in sequence.

[0021] Example 2 The production line of Example 1 is used to produce high-line products under the TMCP process, and the specific steps are as follows: The cold continuous casting billet is heated in the heating furnace after being fed through the loading platform, the furnace roller and weighed. The temperature of the first heating stage is 760℃, the temperature of the second heating stage is 960℃, the temperature of the equalizing stage is 970℃. The billet is heated to 910℃ in the heating furnace and taken out of the furnace after being heated for 2 hours.

[0022] After the billet comes out of the furnace, it is descaled with high-pressure water, rolled by seven rough rolling mills, cut by 1# flying shear, rolled by six intermediate rolling mills, cut by 2# flying shear, rolled by four pre-finishing rolling mills, and rolled by two module rolling mills. The steel temperature is raised from 910℃ to 1020℃, and then dropped to 880℃ after passing through 1# water tank and 2# water tank. 3# flying shear is set behind 1# water tank and 2# water tank to cut off all the blackheads caused by water penetration on the head of the steel. Therefore, 1# water tank and 2# water tank can use the normally open mode to eliminate all the non-cooling sections in this area caused by water penetration cooling.

[0023] After the 3# flying shear cuts, the steel enters the finishing mill for rolling, and the steel temperature rises from 880℃ to 980℃, and then cools through the 3# water tank, 4# water tank, and 5# water tank, and the steel temperature drops to 780℃. The 4# flying shear is set after the 3# water tank, 4# water tank, and 5# water tank to cut off all the blackheads caused by water penetration at the head of the steel. Therefore, the 3# water tank, 4# water tank, and 5# water tank can use the normally open mode to eliminate all the non-cooling sections caused by water penetration cooling in this area.

[0024] The steel after passing through the No. 4 flying shear enters the mini rolling mill for rolling. The steel temperature rises from 780 °C to 860 °C. When the head of the steel reaches the No. 3 pinch roll 1 meter away from the discharge port of the mini rolling mill, the No. 3 pinch roll immediately grips it, and the No. 6 water tank immediately starts to supply water. When the head of the steel reaches the No. 4 pinch roll after passing through the No. 6 water tank, the No. 4 pinch roll immediately grips it, and the No. 7 water tank and the No. 8 water tank immediately start to supply water. The lengths of the non-cooling sections of the No. 6 water tank, the No. 7 water tank, and the No. 8 water tank can be set to 0 meters, and even the always-open mode can be applied. Then, after being gripped by the pinch roll in front of the coiler, the steel is coiled, and the steel temperature drops to 780 °C.

[0025] After coiling, the high-speed wire products sequentially pass through the Stelmor line and are collected by the coiler drum. Then the obtained products are transported to the vertical coiler mandrel for placement, and then conveyed to the P&F conveyor line by the coil car. After bundling, weighing, and tagging, the coils are unloaded and finally stored in the warehouse.

[0026] After testing, for the high-speed wire products produced by the method of this embodiment, the length of the non-cooling section at the head can be controlled within 3 to 10 meters.

[0027] Example 3 Using the production line of Example 1 to produce high-speed wire products under the TMCP process, the specific steps are as follows: The hot continuous casting billet is heated in the heating furnace after passing through the charging table, the furnace roller table, and weighing. The temperature in the first heating section is 860 °C, the temperature in the second heating section is 1040 °C, and the soaking section temperature is 1030 °C. The billet is heated to 950 °C in the heating furnace and then discharged after 1.5 hours in the heating furnace.

[0028] After the billet is discharged from the furnace, it undergoes high-pressure water descaling, rolling by seven roughing mills, shearing of the head and tail by the No. 1 flying shear, rolling by six intermediate mills, shearing of the head and tail by the No. 2 flying shear, rolling by four pre-finishing mills, and rolling by two modular mills. Then the steel temperature rises from 950 °C to 1050 °C, and after passing through the No. 1 water tank and the No. 2 water tank, the steel temperature drops to 950 °C. A No. 3 flying shear is set after the No. 1 water tank and the No. 2 water tank, which can cut off all the black heads generated at the head of the steel due to water penetration. Therefore, the No. 1 water tank and the No. 2 water tank can use the always-open mode to eliminate all the non-cooling sections caused by water penetration cooling in this area.

[0029] The steel after passing through the No. 3 flying shear enters the finishing mill for rolling. The steel temperature rises from 950 °C to 1050 °C, and then is cooled by the No. 3 water tank, the No. 4 water tank, and the No. 5 water tank, and the steel temperature drops to 830 °C. A No. 4 flying shear is set after the No. 3 water tank, the No. 4 water tank, and the No. 5 water tank, which can cut off all the black heads generated at the head of the steel due to water penetration. Therefore, the No. 3 water tank, the No. 4 water tank, and the No. 5 water tank can use the always-open mode to eliminate all the non-cooling sections caused by water penetration cooling in this area.

[0030] The steel after passing through the 4# flying shear enters the mini rolling mill for rolling. The steel temperature rises from 830°C to 910°C. When the head of the steel reaches the 3# pinch roll 1 meter away from the discharge port of the mini rolling mill, the 3# pinch roll immediately clamps it, and the 6# water tank immediately starts to supply water. When the head of the steel reaches the 4# pinch roll after passing through the 6# water tank, the 4# pinch roll immediately clamps it, and the 7# water tank and 8# water tank immediately start to supply water. The 6# water tank, 7# water tank, and 8# water tank can set the length of the non-cooling section to 0 meters, or even achieve the application of the always-open mode. Then, after being clamped by the pinch roll in front of the coiler, the steel is coiled, and the steel temperature drops to 810°C.

[0031] After coiling, the high-speed wire products pass through the Stelmor line and the coiling reel for collection in sequence. Then the obtained products are transported to the vertical coiler mandrel for placement, and then conveyed to the P&F conveyor line by the coil transfer car. After bundling, weighing, and tagging, the coils are unloaded and finally stored in the warehouse.

[0032] After testing, for the high-speed wire products produced by the method of this embodiment, the length of the non-cooling section at the head can be controlled within 3 - 10 meters.

[0033] Comparative Example 1 A production line for shortening the non-cooling section of high-speed wire under the TMCP process includes a loading table. The loading table is connected to the feeding port of the heating furnace through the charging roller table. The discharging port of the heating furnace is connected to the feeding port of the rough rolling mill through the discharging roller table. The rough rolling mill includes six rough rolling mills. The discharging port of the rough rolling mill is connected to the 1# flying shear and the intermediate rolling mill in sequence. The intermediate rolling mill includes eight intermediate rolling mills. A 2# flying shear is provided between the first six intermediate rolling mills and the last two intermediate rolling mills. The discharging port of the intermediate rolling mill is connected to the pre-finishing mill. The pre-finishing mill includes four pre-finishing mills. The discharging port of the pre-finishing mill is connected to the 1# pinch roll, the 3# flying shear, and the finishing mill in sequence. A 1# water tank is provided between the discharging port of the pre-finishing mill and the 1# pinch roll. The discharging port of the finishing mill is connected to the pinch roll in front of the coiler and the coiler in sequence. A 2# water tank, a 3# water tank, and a 4# water tank are provided between the discharging port of the finishing mill and the pinch roll in front of the coiler. The pinch roll in front of the coiler is connected to the coiler. The discharging port of the coiler is connected to the Stelmor line and the coiling reel in sequence.

[0034] Using the above production line to produce high-speed wire products under the TMCP process, the specific steps are as follows: The cold continuous casting billet is loaded onto the loading table, passed through the charging roller table, weighed, and then enters the heating furnace for heating. The temperature of the first heating section is 850°C, the temperature of the second heating section is 1000°C, and the soaking section temperature is 1040°C. The steel billet is heated to 970°C in the heating furnace and discharged after 1.5 hours in the heating furnace.

[0035] After the steel billet comes out of the furnace, it is descaled by high-pressure water, rolled by six rough rolling mills, cut by 1# flying shear, rolled by six intermediate rolling mills, cut by 2# flying shear, rolled by two intermediate rolling mills, and rolled by four pre-finishing rolling mills. The steel temperature is raised from 950℃ to 1070℃, and then dropped to 900℃ after passing through 1# water tank. 3# flying shear is set after 1# water tank, the water tank uses automatic mode, and the non-cooling section is set to 0~5 meters.

[0036] After the 3# flying shear cutter, the steel enters the finishing mill for rolling, and the steel temperature rises from 900℃ to 1020℃. When the head of the steel reaches the front pinch roller of the laying head, the front pinch roller of the laying head clamps it immediately, and the 2#, 3#, and 4# water tanks immediately open water for cooling, and the steel temperature drops to 900℃. The 2#, 3#, and 4# water tanks can set the length of the non-cooling section to 50 meters.

[0037] After spinning, the high-wire products are collected by the Stelmore line and the collection drum in turn. Then the obtained products are transferred to the vertical winding core rack for placement, and then transported to the P&F transportation line by the coil transport trolley. After bundling, weighing and labeling, the coils are unloaded and finally put into storage.

[0038] After testing, it was found that the length of the head non-cooling section of the conventionally configured high-wire product was 50 to 60 meters, which was 40 to 57 meters longer than the non-cooling section of the embodiment of the present invention, resulting in a reduction in the yield rate of more than 0.5% and an increase in the processing cost of more than 2.5 yuan / ton.

[0039] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any person of ordinary skill in the art may easily conceive of changes or substitutions within the technical scope disclosed by the present invention, and such changes or substitutions shall be within the scope of protection of the present invention.

Claims

1. A production line for shortening the non-cooling section of finished high-speed wire under TMCP process, including a loading table, characterized in that, The charging table is connected to the feeding port of the heating furnace through the charging roller table. The discharging port of the heating furnace is connected to the feeding port of the rough rolling mill through the discharging roller table. The discharging port of the rough rolling mill is successively connected to the No. 1 flying shear and the intermediate rolling mill. The discharging port of the intermediate rolling mill is successively connected to the No. 2 flying shear, the pre-finishing mill and the modular rolling mill. The discharging port of the modular rolling mill is successively connected to the No. 1 pinch roll, the No. 3 flying shear and the finishing mill. The discharging port of the finishing mill is successively connected to the No. 2 pinch roll, the No. 4 flying shear and the mini rolling mill. The discharging port of the mini rolling mill is successively connected to the No. 3 pinch roll, the No. 4 pinch roll, the pinch roll before the coiler and the coiler; A No. 1 water tank and a No. 2 water tank are arranged between the discharging port of the modular rolling mill and the No. 1 pinch roll; A No. 3 water tank, a No. 4 water tank and a No. 5 water tank are arranged between the discharging port of the finishing mill and the No. 4 flying shear; A No. 6 water tank is arranged between the No. 3 pinch roll and the No. 4 pinch roll, and a No. 7 water tank and a No. 8 water tank are arranged between the No. 4 pinch roll and the pinch roll before the coiler.

2. The production line according to claim 1, characterized in that, The No. 3 pinch roll is configured 1 meter away from the discharging port of the mini rolling mill.

3. The production line according to claim 1, characterized in that, The rough rolling mill includes 7 rough rolling stands, the intermediate rolling mill includes 6 intermediate rolling stands, the pre-finishing mill includes 4 pre-finishing stands, and the modular rolling mill includes 2 modular rolling stands.

4. The production line according to claim 1, wherein The discharging port of the coiler is successively connected to the Stelmor line and the coiling reel.

5. A method for shortening the non-cooling section of finished high-speed wire under TMCP process, characterized in that, It includes the following steps: (1) Charge the continuous casting billet into the heating furnace for heating. The temperature of the first heating stage is 760 - 860 °C, the temperature of the second heating stage is 960 - 1040 °C, and the soaking temperature is 970 - 1030 °C. The billet is heated in the heating furnace to 910 - 950 °C and discharged after the heating time ≥ 1.5 hours; (2) After the billet is rolled by the rough rolling mill, the intermediate rolling mill, the pre-finishing mill and the modular rolling mill, the steel temperature rises from 910 - 950 °C to 1020 - 1050 °C, and then is cooled by the No. 1 water tank and the No. 2 water tank, and the steel temperature drops to 880 - 950 °C; (3) The steel after being sheared by the No. 3 flying shear enters the finishing mill for rolling. The steel temperature rises from 880 - 950 °C to 980 - 1050 °C, and then is cooled by the No. 3 water tank, the No. 4 water tank and the No. 5 water tank, and the steel temperature drops to 780 - 830 °C; (4) The steel after being sheared by the No. 4 flying shear enters the mini rolling mill for rolling. The steel temperature rises from 780 - 830 °C to 860 - 910 °C, and then is clamped by the No. 3 pinch roll, cooled by the No. 6 water tank, clamped by the No. 4 pinch roll, cooled by the No. 7 and No. 8 water tanks, and clamped by the pinch roll before the coiler and then coiled, and the steel temperature drops to 780 - 810 °C.

6. The method according to claim 5, characterized in that The continuous casting billet is charged into the heating furnace cold or hot.

7. The method according to claim 5, wherein The No. 1 water tank and the No. 2 water tank are in the normally open mode.

8. The method according to claim 5, characterized in that The No. 3 water tank, the No. 4 water tank and the No. 5 water tank are in the normally open mode.

9. The method according to claim 5, wherein The No. 6 water tank, the No. 7 water tank and the No. 8 water tank are in the normally open mode.

10. The method according to claim 5, characterized in that, After being collected by the coiling reel, the product is transported to the vertical core rack for placement, and then conveyed to the P&F conveyor line by the coil car.

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