A production line and method for shortening the non-cooling section of finished products using TMCP process.

Abstract

This invention relates to the field of steel production technology, specifically to a production line and method for shortening the non-cooled section of high-speed wire rod under the TMCP process. The production line includes a loading platform connected to the furnace inlet via an inlet roller conveyor. The furnace outlet is connected to the roughing mill, No. 1 flying shear, intermediate mill, No. 2 flying shear, pre-finishing mill, and modular mill via an outlet roller conveyor. The modular mill outlet is sequentially connected to No. 1 pinch roll, No. 3 flying shear, and finishing mill. The finishing mill outlet is sequentially connected to No. 2 pinch roll, No. 4 flying shear, mini mill, No. 3 pinch roll, No. 4 pinch roll, front pinch roll of the wire rod feeder, and the wire rod feeder. This invention enables minimal shearing of the non-cooled section at the head of high-speed wire rod produced using the TMCP process, reducing the length of the non-cooled section from 50-60 meters to 3-10 meters.

Description

Technical Field

[0001] This invention relates to the field of steel production technology, specifically to a production line and method for shortening the non-cooling section of finished products using the TMCP process. Background Technology

[0002] High-speed wire rod, short for high-speed wire, is a type of coil rolled using a high-speed, twist-free rolling mill. The diameter of high-speed wire rod typically ranges from 5.5 to 14 mm, and each coil weighs between 1.8 and 2.7 tons. Compared to ordinary wire rod (rolled using a conventional rolling mill), high-speed wire rod offers higher dimensional tolerances and better mechanical properties.

[0003] Currently, most high-speed wire rod mills in China use the TMCP process to produce rebar. The TMCP process requires water cooling of the steel during and after rolling. Due to the small dimensions and high speed of high-speed wire rod rolling, to prevent steel from piling up in the water tanks due to water resistance, each tank has a head-uncooled section, especially the tank after the finishing mill. After the steel is clamped by the pinch rolls before the wire rod mill, the cooling water in the tank is turned on, resulting in a certain length of head-uncooled section. The length of this head-uncooled section depends on the distance from the finishing mill to the pinch rolls. Most high-speed wire rod mills are more than 50 meters away from the pinch rolls of the wire rod mill, resulting in head-uncooled sections exceeding 50 meters.

[0004] Because the steel temperature is high in the non-cooled section at the head of the high-strength wire rod, the steel performance is lower than the standard requirements. In order to ensure the quality of the product, the non-cooled section at the head needs to be cut off manually. As a result, the yield of high-strength wire rod produced by the TMCP process is more than 0.5% lower than that of conventional processes. Summary of the Invention

[0005] To address the technical problem of excessively long non-cooled section at the head of high-speed wire rod products manufactured using the TMCP process, this invention provides a production line and method for shortening the non-cooled section of the finished product using the TMCP process.

[0006] The technical solution of this invention is as follows:

[0007] In a first aspect, the present invention provides a production line for shortening the non-cooled section of the finished product using the TMCP process, comprising a feeding platform, which is connected to the inlet of the heating furnace via an inlet roller conveyor, and the outlet of the heating furnace is connected to the inlet of the roughing mill via an outlet roller conveyor. The outlet of the roughing mill is sequentially connected to a No. 1 flying shear and an intermediate mill, and the outlet of the intermediate mill is sequentially connected to a No. 2 flying shear, a pre-finishing mill, and a modular mill, and the outlet of the modular mill is sequentially connected to a No. 1 pinch roll, a No. 3 flying shear, and a finishing mill, and the outlet of the finishing mill is sequentially connected to a No. 2 pinch roll, a No. 4 flying shear, and a mini mill, and the outlet of the mini mill is sequentially connected to a No. 3 pinch roll, a No. 4 pinch roll, a pinch roll in front of the spinning mill, and the spinning mill.

[0008] The modular rolling mill unit is equipped with water tank No. 1 and water tank No. 2 between the discharge port of the No. 1 pinch roll;

[0009] Water tanks #3, #4, and #5 are installed between the discharge port of the finishing mill and the #4 flying shear.

[0010] A water tank of No. 6 is provided between the No. 3 pinch roller and the No. 4 pinch roller, and a water tank of No. 7 and a water tank of No. 8 are provided between the No. 4 pinch roller and the pinch roller in front of the spinning machine.

[0011] Furthermore, a No. 3 pinch roll is installed 1 meter from the discharge port of the mini rolling mill.

[0012] Furthermore, the roughing mill group includes seven roughing mills, the intermediate mill group includes six intermediate mills, the pre-finishing mill group includes four pre-finishing mills, and the modular mill group includes two modular mills.

[0013] Furthermore, the discharge port of the spinning machine is connected in sequence to the Stellmore line and the collecting drum.

[0014] Secondly, the present invention provides a method for shortening the non-cooled section of a finished product using a high-speed wire rod milling process under TMCP technology, comprising the following steps:

[0015] (1) The steel billet is heated in a heating furnace. The temperature of the first heating stage is 760~860℃, the temperature of the second heating stage is 960~1040℃, and the temperature of the soaking stage is 970~1030℃. The billet is heated in the heating furnace to 910~950℃ and taken out of the furnace after a heating time of ≥1.5 hours.

[0016] (2) After the billet is rolled by roughing, intermediate rolling, pre-finishing rolling and modular rolling mill, the steel temperature is raised from 910~950℃ to 1020~1050℃, and then cooled by No. 1 water tank and No. 2 water tank, the steel temperature drops to 880~950℃;

[0017] (3) The steel after passing through the No. 3 flying shear head enters the finishing mill for rolling. The steel temperature is raised from 880~950℃ to 980~1050℃. Then it is cooled by the No. 3 water tank, No. 4 water tank and No. 5 water tank, and the steel temperature drops to 780~830℃.

[0018] (4) The steel after passing through the No. 4 flying shear head enters the mini rolling mill for rolling. The steel temperature rises from 780~830℃ to 860~910℃. Then it 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, clamped by the front pinch roll of the wire drawing machine and then wired. The steel temperature drops to 780~810℃.

[0019] Furthermore, the steelmaking continuous casting billets are either cold-charged or hot-charged into the heating furnace for heating.

[0020] Furthermore, water tanks #1 and #2 are operated in a normally open mode.

[0021] Furthermore, water tanks #3, #4, and #5 are operated in a normally open mode.

[0022] Furthermore, water tanks #6, #7, and #8 are operated in a normally open mode.

[0023] Furthermore, after being collected by the roll collection drum, the products are transferred to the vertical roll core rack for placement, and then transported to the P&F transport line via a roll transport trolley.

[0024] The beneficial effects of this invention are as follows:

[0025] To avoid steel piling up in the area between the mini rolling mill and the wire drawing machine due to high speed and large water resistance, this invention configures multiple pinch rolls in this area to achieve the shortest possible length of the non-cooled section (0 meters).

[0026] This invention achieves minimal shearing of the head section of high-speed wire rod produced using the TMCP process by precisely controlling the initial rolling temperature, the temperature entering the finishing mill, the temperature entering the mini mill, and the wire exit temperature. It also utilizes the normally open mode of the water tanks after the pre-finishing mill (tanks #1 and #2) and the finishing mill (tanks #3, #4, and #5), and sets the minimum length of the non-cooled section in the mini mill's water tank. This reduces the length of the head section from 50-60 meters to approximately 3-10 meters, increases the yield by more than 0.5% compared to high-speed wire rod produced with the same process and typical configurations, reduces processing costs by more than 2.5 yuan / ton, and significantly reduces the labor intensity of workers shearing the head and tail sections. Attached Figure Description

[0027] Figure 1 This is a process flow diagram of the production line for producing high-speed wire products according to a specific embodiment of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0029] Example 1

[0030] A production line for shortening the non-cooled section of a finished product using TMCP (Transformer-Modified Plasma Process) includes a loading platform connected to the furnace feed inlet via an inlet roller conveyor. The furnace discharge outlet is connected to the roughing mill feed inlet via an outlet roller conveyor. The roughing mill comprises seven roughing mill stands, with its discharge outlet sequentially connected to a No. 1 flying shear and an intermediate mill. The intermediate mill comprises six intermediate mill stands, with its discharge outlet sequentially connected to a No. 2 flying shear, a pre-finishing mill, and a modular mill. The pre-finishing mill comprises four pre-finishing mill stands, and the modular mill comprises two modular mill stands, with their discharge outlet sequentially connected to a No. 1 pinch roll, a No. 3 flying shear, and the finishing mill. The modular rolling mill is equipped with water tanks #1 and #2 between its discharge port and #1 pinch roll. The finishing mill is connected in sequence to pinch roll #2, flying shear #4, and mini rolling mill. Water tanks #3, #4, and #5 are connected between the finishing mill and flying shear #4. Pinch roll #3 is positioned 1 meter from the discharge port of the mini rolling mill. The discharge port of pinch roll #3 is connected in sequence to pinch roll #4, the pinch roll in front of the spinning machine, and the spinning machine. Water tank #6 is located between pinch roll #3 and pinch roll #4. Water tanks #7 and #8 are located between pinch roll #4 and the pinch roll in front of the spinning machine. The discharge port of the spinning machine is connected in sequence to the Stellmore line and the collecting drum.

[0031] Example 2

[0032] The production line of Example 1 is used to produce high-speed wire rod products under the TMCP process. The specific steps are as follows:

[0033] After being fed onto the loading platform, passed through the furnace roller conveyor, and weighed, the billet is heated in the heating furnace. The first heating stage has a temperature of 760℃, the second heating stage has a temperature of 960℃, and the soaking stage has a temperature of 970℃. The billet is heated to 910℃ in the heating furnace and is removed from the furnace after 2 hours of heating.

[0034] After the billet exits the furnace, it undergoes high-pressure water descaling, rolling on seven roughing mills, shearing the head and tail of the billet with a No. 1 flying shear, rolling on six intermediate mills, shearing the head and tail of the billet with a No. 2 flying shear, rolling on four pre-finishing mills, and rolling on two modular mills. The steel temperature rises from 910℃ to 1020℃. After passing through No. 1 and No. 2 water tanks, the steel temperature drops to 880℃. A No. 3 flying shear is installed after No. 1 and No. 2 water tanks to completely remove the black head caused by water cooling. Therefore, No. 1 and No. 2 water tanks can be used in a normally open mode to completely eliminate the uncooled section caused by water cooling in this area.

[0035] The steel, after passing through the No. 3 flying shear head, enters the finishing mill for rolling, where the steel temperature rises from 880℃ to 980℃. It then passes through water tanks No. 3, No. 4, and No. 5 for cooling, reducing the temperature to 780℃. A No. 4 flying shear is installed after water tanks No. 3, No. 4, and No. 5 to completely remove the blackheads caused by water quenching at the steel's head. Therefore, water tanks No. 3, No. 4, and No. 5 can operate in a normally open mode, eliminating any uncooled sections caused by water quenching in this area.

[0036] After passing through the No. 4 flying shear head, the steel enters the mini rolling mill for rolling. The steel temperature rises from 780℃ to 860℃. When the head of the steel reaches the No. 3 pinch roll 1 meter from the outlet of the mini rolling mill, the No. 3 pinch roll immediately clamps it, and the No. 6 water tank immediately turns on the water. When the head of the steel reaches the No. 6 water tank, the No. 4 pinch roll immediately clamps it, and the No. 7 and No. 8 water tanks immediately turn on the water. The length of the non-cooled section of the No. 6, No. 7, and No. 8 water tanks can be set to 0 meters, or even used in a normally open mode. Then, the wire is clamped by the pinch roll in front of the wire feeder and the wire is fed, and the steel temperature drops to 780℃.

[0037] After spinning, the high-strength wire products pass through the Stellmore line and are collected by the collecting drum. The resulting products are then transferred to the vertical core rack and transported to the P&F transport line via a trolley. After bundling, weighing, and tagging, the coils are unloaded and finally stored in the warehouse.

[0038] Tests have shown that the length of the non-cooled section at the head of the high-strength wire produced by the method of this embodiment can be controlled within 3 to 10 meters.

[0039] Example 3

[0040] The production line of Example 1 is used to produce high-speed wire rod products under the TMCP process. The specific steps are as follows:

[0041] After being fed onto the loading platform, fed onto the furnace roller conveyor, and weighed, the hot continuous casting billet is heated in the heating furnace. The first heating stage has a temperature of 860℃, the second heating stage has a temperature of 1040℃, and the soaking stage has a temperature of 1030℃. The billet is heated to 950℃ in the heating furnace and is removed from the furnace after 1.5 hours of heating.

[0042] After the steel billet exits the furnace, it undergoes high-pressure water descaling, rolling on seven roughing mills, shearing the head and tail of the billet with a No. 1 flying shear, rolling on six intermediate mills, shearing the head and tail of the billet with a No. 2 flying shear, rolling on four pre-finishing mills, and rolling on two modular mills. The steel temperature is then raised from 950℃ to 1050℃. After passing through No. 1 and No. 2 water tanks, the steel temperature is reduced to 950℃. A No. 3 flying shear is installed after No. 1 and No. 2 water tanks to completely remove the black head caused by water cooling. Therefore, No. 1 and No. 2 water tanks can be used in a normally open mode to completely eliminate the uncooled section caused by water cooling in this area.

[0043] The steel, after passing through the No. 3 flying shear head, enters the finishing mill for rolling, where the steel temperature is raised from 950℃ to 1050℃. It is then cooled by water tanks No. 3, No. 4, and No. 5, reducing the temperature to 830℃. A No. 4 flying shear is installed after water tanks No. 3, No. 4, and No. 5 to completely remove the blackheads caused by water quenching at the steel head. Therefore, water tanks No. 3, No. 4, and No. 5 can operate in a normally open mode, eliminating any uncooled sections caused by water quenching in this area.

[0044] After passing through the No. 4 flying shear head, the steel enters the mini rolling mill for rolling. The steel temperature rises from 830℃ to 910℃. When the head of the steel reaches the No. 3 pinch roll 1 meter from the outlet of the mini rolling mill, the No. 3 pinch roll immediately clamps it, and the No. 6 water tank immediately turns on the water. When the head of the steel reaches the No. 6 water tank, the No. 4 pinch roll immediately clamps it, and the No. 7 and No. 8 water tanks immediately turn on the water. The length of the non-cooled section of the No. 6, No. 7, and No. 8 water tanks can be set to 0 meters, or even used in a normally open mode. Then, the wire is clamped by the pinch roll in front of the wire feeder and the wire is fed, and the steel temperature drops to 810℃.

[0045] After spinning, the high-strength wire products pass through the Stellmore line and are collected by the collecting drum. The resulting products are then transferred to the vertical core rack and transported to the P&F transport line via a trolley. After bundling, weighing, and tagging, the coils are unloaded and finally stored in the warehouse.

[0046] Tests have shown that the length of the non-cooled section at the head of the high-strength wire produced by the method of this embodiment can be controlled within 3 to 10 meters.

[0047] Comparative Example 1

[0048] A production line for shortening the non-cooled section of finished product using TMCP process includes a loading platform connected to the furnace feed inlet via an inlet roller conveyor. The furnace discharge outlet is connected to the roughing mill feed inlet via an outlet roller conveyor. The roughing mill comprises six roughing mill stands, with its discharge outlet sequentially connected to a No. 1 flying shear and an intermediate mill. The intermediate mill comprises eight intermediate mill stands, with a No. 2 flying shear located between the first six intermediate mill stands and the last two. The discharge outlet of the intermediate mill is connected to a pre-finishing mill. Next, the pre-finishing mill unit includes four pre-finishing mill stands. The discharge port of the pre-finishing mill unit is connected in sequence to the No. 1 pinch roll, the No. 3 flying shear, and the finishing mill unit. A No. 1 water tank is installed between the discharge port of the pre-finishing mill unit and the No. 1 pinch roll. The discharge port of the finishing mill unit is connected in sequence to the pinch roll in front of the wire spinneret and the wire spinneret. A No. 2 water tank, a No. 3 water tank, and a No. 4 water tank are installed between the discharge port of the finishing mill unit and the pinch roll in front of the wire spinneret. The pinch roll in front of the wire spinneret is connected to the wire spinneret. The discharge port of the wire spinneret is connected in sequence to the Stellmore wire and the collecting drum.

[0049] The specific steps for producing high-speed wire rod products using the above production line under the TMCP process are as follows:

[0050] After being fed through the loading platform, the furnace roller conveyor, and weighed, the cooled continuous casting billet is heated in the heating furnace. The first heating stage is 850℃, the second heating stage is 1000℃, and the soaking stage is 1040℃. The billet is heated to 970℃ in the heating furnace and removed from the furnace after 1.5 hours.

[0051] After the billet exits the furnace, it undergoes high-pressure water descaling, rolling on six roughing mills, shearing the head and tail of the No. 1 flying shear, rolling on six intermediate mills, shearing the head and tail of the No. 2 flying shear, rolling on two intermediate mills, and rolling on four pre-finishing mills. The steel temperature is raised from 950℃ to 1070℃, and then cooled to 900℃ in the No. 1 water tank. The No. 3 flying shear is installed after the No. 1 water tank. The water tanks are set in automatic mode, and the non-cooling section is set from 0 to 5 meters.

[0052] The steel, after passing through the No. 3 flying shear head, enters the finishing mill for rolling, where the steel temperature rises from 900℃ to 1020℃. The steel head reaches the clamping rolls in front of the wire drawing machine, where it is immediately clamped. Water tanks No. 2, No. 3, and No. 4 immediately begin cooling, reducing the steel temperature to 900℃. The length of the non-cooled section in water tanks No. 2, No. 3, and No. 4 can be set to 50 meters.

[0053] After spinning, the high-strength wire products pass through the Stellmore line and are collected by the collecting drum. The resulting products are then transferred to the vertical core rack and transported to the P&F transport line via a trolley. After bundling, weighing, and tagging, the coils are unloaded and finally stored in the warehouse.

[0054] Tests showed that the length of the non-cooled section at the head of the conventionally configured high-strength wire rod product is 50-60 meters, which is 40-57 meters longer than the non-cooled section length in the embodiment of this invention. This results in a yield reduction of more than 0.5% and an increase in processing cost of more than 2.5 yuan / ton.

[0055] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Various equivalent modifications or substitutions can be made to the embodiments of the present invention by those skilled in the art without departing from the spirit and essence of the invention, and such modifications or substitutions should all be within the scope of the present invention. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should also be covered within the protection scope of the present invention.

Claims

1. A method for shortening the non-cooled section of a finished product using a high-speed wire rod mill under a TMCP process, characterized in that, Includes the following steps: (1) The steel billet is heated in a heating furnace. The temperature of the first heating stage is 760~860℃, the temperature of the second heating stage is 960~1040℃, and the temperature of the soaking stage is 970~1030℃. The billet is heated in the heating furnace to 910~950℃ and taken out of the furnace after a heating time of ≥1.5 hours. (2) After the billet is rolled by roughing, intermediate rolling, pre-finishing rolling and modular rolling mill, the steel temperature is raised from 910~950℃ to 1020~1050℃, and then cooled by No. 1 water tank and No. 2 water tank, the steel temperature drops to 880~950℃; (3) The steel after passing through the No. 3 flying shear head enters the finishing mill for rolling. The steel temperature is raised from 880~950℃ to 980~1050℃. Then it is cooled by the No. 3 water tank, No. 4 water tank and No. 5 water tank, and the steel temperature drops to 780~830℃. (4) The steel after passing through the No. 4 flying shear head enters the mini rolling mill for rolling. The steel temperature rises from 780~830℃ to 860~910℃. Then it 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, clamped by the pinch roll in front of the wire drawing machine and then wired. The steel temperature drops to 780~810℃. The production line used in the method for shortening the non-cooled section of the finished product under the TMCP process includes a feeding platform. The feeding platform is characterized by being connected to the inlet of the heating furnace via an inlet roller conveyor. The outlet of the heating furnace is connected to the inlet of the roughing mill via an outlet roller conveyor. The outlet of the roughing mill is sequentially connected to the No. 1 flying shear and the intermediate mill. The outlet of the intermediate mill is sequentially connected to the No. 2 flying shear, the pre-finishing mill, and the modular mill. The outlet of the modular mill is sequentially connected to the No. 1 pinch roll, the No. 3 flying shear, and the finishing mill. The outlet of the finishing mill is sequentially connected to the No. 2 pinch roll, the No. 4 flying shear, and the mini mill. The outlet of the mini mill is sequentially connected to the No. 3 pinch roll, the No. 4 pinch roll, the pinch roll before the spinning mill, and the spinning mill. The modular rolling mill is equipped with water tanks #1 and #2 between the discharge port and the #1 pinch roll. Water tanks #3, #4, and #5 are installed between the discharge port of the finishing mill and the #4 flying shear. A water tank #6 is installed between pinch roller #3 and pinch roller #4, and water tanks #7 and #8 are installed between pinch roller #4 and the pinch roller in front of the spinning machine. The mini rolling mill is equipped with a No. 3 pinch roll 1 meter from the discharge port.

2. The method as described in claim 1, characterized in that, The roughing mill group includes 7 roughing mills, the intermediate mill group includes 6 intermediate mills, the pre-finishing mill group includes 4 pre-finishing mills, and the modular mill group includes 2 modular mills.

3. The method as described in claim 1, characterized in that, The discharge port of the spinning machine is connected in sequence to the Stellmore line and the collecting drum.

4. The method as described in claim 1, characterized in that, Steelmaking continuous casting billets are cold-charged or hot-charged into the heating furnace for heating.

5. The method as described in claim 1, characterized in that, Water tanks #1 and #2 are in normally open mode.

6. The method as described in claim 1, characterized in that, Water tanks #3, #4, and #5 are in normally open mode.

7. The method as described in claim 1, characterized in that, Water tanks #6, #7, and #8 are in normally open mode.

8. The method as described in claim 1, characterized in that, After being collected by the collecting drum, the products are transferred to the vertical core rack and then transported to the P&F transport line by the transport trolley.

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