CN107597844A - The ferrite rolling method and apparatus that endless casting rolling deep-draw is rolled up with humble carbon steel - Google Patents

Abstract

The ferrite rolling method and apparatus that a kind of endless casting rolling deep-draw is rolled up with humble carbon steel, belong to metallurgical steel rolling field.The ferrite rolling method and apparatus that endless casting rolling production deep-draw is rolled up with humble carbon steel are batched to be casting continuously to form base → roughing mills roughing → cooling duct temperature control → high-pressure water descaling → mm finishing mill unit ferrite rolling → layer device for cooling cooling → high-speed flying shear bundling → coiling machine.The inventive method and device before solving conventional hot rolling technology roughing need that the problem of temperature cooling need to be treated between heating stove heat/soaking, austenitic area roughing and ferrite area finish rolling because the temperature difference is big and the continuous casting and rolling technique of sheet bar using CSP as representative need to heat stove heat/soaking or sensing heating mends the problems such as temperature, with characteristics of compact layout, small investment, production efficiency height, safe and reliable, energy-conserving and environment-protective and the advantages such as cost are reduced, realize endless casting rolling and ferrite rolling production deep-draw low-carbon/micro- carbon steel volume.

Description

Ferrite rolling method and device for low carbon steel coil for endless continuous casting and rolling deep drawing

technical field

The invention belongs to the technical field of metallurgical steel rolling, and in particular provides a ferrite rolling method and device for producing low-micro-carbon steel coils for deep drawing by endless continuous casting and rolling.

Background technique

Thin slab continuous casting and rolling technology is a new technology that appeared in the late 1980s. Mainly include the CSP process of German SMS company, which adopts roller hearth furnace for heating, soaking and heat preservation, and the CPR process cooperated with German Thyssen factory can realize semi-endless rolling; the ISP process of German MDS company, the intermediate billet is heated by induction and hot coil box-type soaking, which can realize semi-endless rolling; the FTSR process of Italian Danieli company has liquid core reduction technology, which is heated and kept in a roller hearth tunnel furnace and then rough rolled. There are thermal insulation roller tables; Japan’s Sumitomo Metal’s QSP process, the continuous casting slab is heated by a roller hearth furnace, and the rough rolling and finishing rolling are intermediate conveying roller tables with heating functions; voestalpine’s CONROLL process has induction side Head heater and roller hearth soaking furnace; Italian Arvedi company's ESP process, continuous casting includes liquid core reduction, soft reduction, etc., induction heating is used between finishing and rough rolling, which can realize endless rolling. "A strip steel production process—ESP" (Lv Kunyong, Chinese patent, 200510057404.5) proposes a new ESP process: continuous casting machine (liquid core pressing)→swing shearing and splitting→heating furnace→descaler→rough rolling mill→ Descaling→finishing rolling unit→laminar cooling→coiler. The BCT process of SMS company in Germany is directly rolled after continuous casting, and can continuously cast 15mm thick non-finished steel strips, but this technology is not mature, and is currently used for HSD steels with high manganese, silicon and aluminum content. The conventional semi-continuous hot rolling process uses a single slab to be rolled, and the slab is heated, soaked and kept warm in a roller hearth furnace, and a hot coil box is required for the production of thin-gauge products.

Endless rolling and semi-endless rolling technologies are new steel plate rolling technologies that have emerged in recent years that can reduce energy consumption, improve efficiency, and reduce costs, and can achieve stable performance of the entire batch. Endless rolling is mainly used in the production of hot-rolled strip steel and rods and wires, and semi-endless rolling is mainly used in the production of thin slab continuous casting and rolling. The first full continuous endless rolling hot strip rolling machine was put into use in Chiba Works of JFE Company in Japan in 1996. The induction heating connection method adopted for the intermediate billet can increase the yield compared with conventional hot rolling. 1%-2%, the roll consumption is reduced by 1%-2%. Subsequently, Japan's Nippon Steel and South Korea's Posco carried out endless rolling transformations for their hot continuous rolling. At present, the connection methods of the intermediate billet after rough rolling mainly include the overlapping rolling connection method, thermite welding connection method, direct energization connection method, induction heating connection method, laser heating connection method, mechanical shearing + pressing connection method, etc., among which " "Connection method of hot-rolled strip endless rolling intermediate billet" (Kang Yonglin, Chinese patent, 201010289783.1) proposes a connecting method of the intermediate billet through cutting head and tail-pressing teeth-lapping-pressing. Alvedi built the world's first endless continuous casting and rolling production line ESP in 2009. Compared with conventional hot rolling, the energy consumption can be increased by 40%-75%, and the production efficiency can be increased by 25%-30%.

The ferrite rolling process (also known as warm rolling, Warm Rolling) was developed by the Belgian Iron and Steel Research Center in the late 1980s, with the aim of producing a cheap, soft steel that can be used directly or for subsequent cold rolling production. , Non-aging hot-rolled sheet, which has attracted widespread attention and research from scholars from all over the world. Due to the large range of ferrite zone and high temperature of ultra-low carbon steel (carbon content <0.01%), the current ferrite rolling process is mainly used in the production of IF steel. "Method and device for producing ferritic rolled steel strip" (Andre Bodin, Chinese patent, 98811974.9) proposes a process suitable for low carbon steel and IF steel: continuous casting→tunnel furnace heating→shearing Cutting into slab sections→rough rolling by rough rolling unit→forced cooling by forced cooling device→storage in uncoil box→shearing→descaling→finish rolling→cooling/heating→shearing→coiling. "Production equipment for hot-rolled strip in ferrite zone and production process for ferrite strip" (W Rode, German patent, 19531538.3; Chinese patent, 96112270.6) proposes a process suitable for low-carbon steel: continuous casting →heating→rough rolling→finish rolling→cooling→(coil)→thin strip mill→coil. "Ferrite zone rolling temperature control system" (Xu Rongchang, Chinese patent, 201010548338.2) proposes to realize ferrite zone rolling on conventional hot rolling production line by adding temperature sensor and billet rolling temperature control system. "Thin slab continuous casting and rolling ferritic rolling process" (Chen Yuguang, Chinese patent, 201310723913.1) proposes a rolling temperature control method for ≤2mm thin plates, the heating temperature is 1100°C-1300°C, and the finish rolling temperature is 600°C-700°C ℃. "A method for producing low-carbon steel using a ferrite rolling process in a CSP production line" (Du Xiufeng, Chinese patent, 201610759108.8) proposes a process suitable for low-carbon steel: continuous casting → heating → descaling → rolling →Laminar flow cooling→coiling, the billet exit temperature is 1020°C-1080°C, and the thickness of the finished product is 2mm-6mm. "A ferritic rolling method" (Wang Jiangong, Chinese patent, 201611039422.5) proposes a method of placing steel before the last pass of rough rolling R2 or before entering the finishing mill to reduce the temperature of the slab, thereby ensuring the finish The rolling temperature is controlled to the ferrite temperature range. "Finish rolling control method and device for a ferritic rolling process" (Wang Jiangong, Chinese patent, 201611059348.3) proposed a method of controlling the deviation of rolling parameters through model self-learning to ensure the quality of ferritic steel. "Method for producing low-carbon steel ferrite based on ESP thin slab continuous casting and rolling process" (Zhou Hongbao, Chinese patent, 201610768866.6) proposed a method for producing low-carbon steel ferrite based on ESP: converter smelting→LF furnace smelting→RH furnace smelting → Continuous casting → Rough rolling → Induction heating → Descaling → Finish rolling → Laminar cooling → Coiling → Cooling to room temperature → Pickling → Leveling → Straightening → Coiling. The document "Research on Ferritic Rolling Low Carbon Steel Plate Process of FTSR Production Line" (Li Yiwei, Proceedings of the Tenth Annual Conference of China Association for Science and Technology (4): 1172-1176; Proceedings of National Steel Rolling Production Technology Conference in 2008: 111-114) proposed The process route is: continuous casting → soaking furnace → 1880mm rolling mill (rough rolling → fast cooling → finishing rolling) → laminar cooling → coiling → cold rolling → recrystallization annealing. "Low-carbon hot-rolled deep-drawing steel plate and its manufacturing method" (Huang Zhenru, Chinese patent, 200510111009.0) proposed methods such as controlling the finish rolling temperature at 830°C-900°C. "Process method for producing pickled deep-drawing plate on CSP production line" (Xu Bin, Chinese patent, 201410152421.6) proposes methods such as controlling the temperature of the soaking process to be 1040°C-1080°C, and the finishing temperature to be 860°C-910°C .

The above various ferrite rolling methods and thin slab continuous casting and rolling technologies have their own characteristics, but because they are restricted by the existing conventional hot rolling production line and thin slab continuous casting and rolling production line, they also have their own shortcomings. , especially heating in the heating furnace before rough rolling, storage in a hot coil box before finishing rolling or swinging steel before finishing rolling, induction heating before finishing rolling, cold rolling, finishing or annealing after hot rolling, etc. Even if the single block or semi-endless rolling technology is transformed into endless rolling by adding intermediate billet connecting devices, there are still problems such as difficult control of process temperature, low production efficiency, high energy consumption for heating, and large investment. In order to reduce production costs and achieve stable, continuous and reliable industrial production, scholars, researchers and industries from various countries are still working hard and exploring, trying to find new ferrite rolling technologies and devices. At present, there is no relevant report on the ferrite rolling method and device of endless continuous casting and rolling in the world. At the same time, judging from the current pressure of China's environmental protection and steel production capacity release, it is still necessary to propose a new thin slab ferrite rolling method and device to simplify the process, reduce costs, improve efficiency, etc., and promote endless continuous casting and rolling. Industrial application of ferritic rolling.

In addition, there is a large market demand for thin-gauge low-carbon steel for deep-drawing grades, which require lower strength, higher elongation and small aging, and most of them are cold-rolled sheets. Studies have shown that conventional hot-rolled thin specifications can cover about 13%-25% of current cold-rolled sheets, and the annual demand for "replacing cold with heat" in my country is about 10-15 million tons. With the advancement of technology, the hot rolling process is used to replace the traditional hot rolling + cold rolling process to produce deep-drawing steel, and the realization of "cooling with hot strips" has become a new hot spot in product development and process development; or to develop thin gauges that are superior to traditional hot coils High-quality hot coil as cold rolling base material can reduce the number of cold rolling, improve the formability of the steel strip after cold rolling, and meet the requirements of ultra-deep drawing or cold-rolling sheets for deep drawing.

Contents of the invention

The purpose of the present invention is to solve the problems of complex technological process, low production efficiency, high energy consumption, high cost, low yield and poor performance stability existing in the existing low-carbon/micro-carbon steel production method and device for deep drawing, and provide A ferritic rolling method and device for producing low-micro-carbon steel coils for deep drawing by endless continuous casting and rolling are disclosed. The device innovates the traditional continuous casting and rolling technology, adopts the endless continuous casting and rolling process, reduces the process of flame cutting into slab segments after conventional continuous casting, improves the site environment, and reduces the slab heating process during conventional rolling And the descaling process after heating, at the same time, only one cutting of the head and tail is carried out in the whole pouring time, which saves the cutting loss of continuous casting, the oxidation burning loss of the heating furnace, the fuel and energy consumption of the heating furnace, and the energy consumption of high-pressure water descaling and water consumption, etc., significantly reducing the loss of cutting head and tail, improving output, yield and performance stability; using thin slab technology and continuous casting high casting speed technology, the traditional casting speed ≤ 3m/min is increased to 4m/min—7m/min, reducing the traditional 5-pass or 7-pass rough rolling to 3 passes, and reducing the traditional 7-pass finish rolling to 5 passes, which improves production efficiency and output; adopts ferrite The solid rolling technology is different from the traditional rolling in the austenite zone. The rough rolling is controlled in the austenite temperature zone of 1020°C-950°C where the rolling stress is low, and the finish rolling is controlled in the rolling stress low valley. Rolling in austenite and ferrite two-phase zone or ferrite zone rolling at 850°C-730°C can obtain high-quality hot coils with excellent formability, and at the same time control the temperature of the cooling channel to ensure that the finishing temperature hits, And to prevent the pearlite phase transformation in the finishing rolling stage from increasing the rolling stress, air cooling or air cooling can be used; the coiling adopts a higher temperature of 710 ° C - 580 ° C, in order to use the residual heat after rolling to achieve ferrite recovery and growth , Release the rolling stress in the two-phase area, etc., improve the deep drawing performance, and save the subsequent annealing treatment. The cooling of the layer cooling device is to ensure that the coiling temperature is hit, and to prevent the formation of coarse pearlite or cementite after coiling, which will affect the drawing performance of the hot plate. The purpose of high-speed flying shear is to obtain the required coil weight. High-pressure water descaling before finishing rolling is to obtain good surface quality of hot coils. At the same time, lubricated rolling by the finishing mill can also reduce rolling pressure and improve surface quality of hot coils. The use of nitrogen-controlled low-carbon/micro-carbon steel alloyed with B, Ti, Cr, Al, etc. is beneficial to reduce the aging phenomenon, increase the casting speed and control the rolling temperature, and is beneficial to the realization of endless continuous casting and rolling, which can realize Batch production of hot coils for deep drawing or high-quality hot coils as cold-rolled base materials for deep drawing or ultra-deep drawing.

The chemical composition and mass percentage of the low-carbon/micro-carbon steel provided by the present invention are: C: 0.008-0.06%, Si≤0.10%, Mn≤0.25%, B≤0.0020%, Ti≤0.030%, Cr≤0.25% , Als: 0.010—0.060%, P≤0.020%, S≤0.015%, N≤0.005%, and the rest are Fe and unavoidable impurities.

The role and mechanism of the main alloying elements:

B: The main function in steel is to increase the hardenability of steel, which is beneficial to continuous casting with high casting speed and temperature control during rolling, but it weakens with the increase of carbon content in steel; at the same time, boron, nitrogen and oxygen It has a strong affinity, adding a certain amount can eliminate the aging phenomenon of steel and inhibit the precipitation of AlN.

Ti: Titanium has a very strong affinity with nitrogen, oxygen, and carbon, and its affinity with sulfur is stronger than that of iron. It is a good deoxidizing and degassing agent and an effective element for fixing nitrogen and carbon, which can eliminate the aging phenomenon of steel; titanium It is also a strong ferrite forming element, which strongly increases the A1 and A3 temperature of steel, increases the ferrite rolling temperature, and is beneficial to the control of rolling temperature.

Cr: The main function of Cr in steel is to improve the hardenability of steel, which is beneficial to the continuous casting with high casting speed and temperature control in the rolling process; it can improve the hardness and wear resistance of carbon steel without making the steel brittle; at the same time It makes steel have good high temperature oxidation resistance and oxidation corrosion resistance; it also increases the thermal strength of steel and has good tempering stability.

Al: Aluminum is a strong deoxidizer. Its main function in steel is to refine grains and fix nitrogen in steel, thereby significantly improving the impact toughness of steel, reducing the tendency of cold brittleness and aging tendency; at the same time, AlN will affect the formability.

N: With the increase of nitrogen content, the strength of the steel can be significantly improved, and the plasticity, especially the toughness, will also be significantly reduced; at the same time, the aging tendency, cold brittleness and hot brittleness will be increased, and the welding performance and cold bending performance of the steel will be damaged. Therefore, the nitrogen content in steel should be minimized and limited.

The technological process of the production line provided by the invention is: billet forming in the continuous casting machine → rough rolling by the rough rolling unit → temperature control in the cooling channel → descaling by high-pressure water → finishing rolling by the finishing rolling unit → cooling by the layer cooling device → high-speed flying shear coiling → coiling Take machine coiling.

The present invention also provides a ferrite rolling device for low carbon steel coils for endless continuous casting and rolling deep drawing, which mainly consists of a slab continuous casting machine 1, a rough rolling unit 2, a cooling channel 3, and a rolling shear 4 , high-pressure water descaling device 5, finishing rolling unit 6, interlayer cooling device 7, high-speed flying shear 8, and coiler 9, and all components are connected in sequence.

Its specific process steps:

1) According to the chemical composition and mass percentage of low-carbon/micro-carbon steel: C: 0.008-0.06%, Si≤0.10%, Mn≤0.25%, B≤0.0020%, Ti≤0.030%, Cr≤0.25%, Als: 0.010—0.060%, P≤0.020%, S≤0.015%, N≤0.005%, and the rest is Fe and unavoidable impurities for smelting.

2) The slab is cast in the continuous casting machine, the temperature target of the continuous casting ladle is 1550°C, and rapid solidification is adopted to prevent grain growth and center segregation; the continuous casting casting speed is 4m/min-7m/min, and the thickness of the slab is 80mm- 130mm.

3) Send directly to the rough rolling unit for rough rolling, the rough rolling temperature is controlled in the austenite temperature zone of 1020°C-950°C, the rough rolling unit preferably has 3 stands, and the thickness of the intermediate billet after rough rolling is 7mm-25mm.

4) The intermediate billet enters the cooling channel for temperature control, the cooling rate is ≤6°C/s, and weak cooling methods such as air cooling or air cooling can be used; the temperature control of the cooling channel is to ensure that the finishing rolling temperature hits to achieve a good deep rolling of ferrite rolling. The punching performance is beneficial to the control of the finish rolling temperature.

5) Rolling shearing head, using rolling shears to cut the head billet of the pouring time, and no longer cut the head until the end of the entire pouring time to realize endless rolling; in emergency cases, the slab can also be separated Blank processing.

6) High-pressure water descaling, in order to ensure the effect of descaling, the pressure of descaling water should be ≥30MPa to ensure that the surface of the intermediate billet is clean before finishing rolling, and to prevent the scale from being pressed in and affecting the surface quality of the hot coil.

7) Finish rolling by the finishing rolling unit, the finishing rolling temperature is controlled in the austenite and ferrite two-phase region or ferrite region between 850°C and 730°C, the finishing rolling group preferably has 5 stands, preferably lubricated rolling, finishing After rolling, the thickness of the finished product is 0.7mm-4mm.

8) Cooling by the layer cooling device, the cooling rate is ≤25°C/s, and the front section, back section and subsection cooling mode can be used to ensure that the pearlite phase transformation occurs at this stage and the coiling temperature hits.

9) High-speed flying shears are divided into coils. In order to ensure the belt threading effect of the layer cooling section, the high-speed flying shears are installed after the layer cooling and before coiling; due to the use of endless rolling technology, the coils are cut according to the coil weight requirements.

10) Coiler coiling, in order to use the waste heat after rolling to realize ferrite recovery and growth, the coiling temperature is controlled at 710°C-580°C, and then natural cooling or slow cooling to room temperature can be used.

11) The performance of the produced low-carbon/micro-carbon steel coil meets the requirements of deep drawing, the tensile strength is 270MPa-400MPa, the elongation is ≥35%, the n value is 0.18-0.25, and the r value is 0.8-1.5, which can be directly used as steel for deep drawing ; It can also be used as a cold-rolled base material for ultra-thin gauge steel for deep drawing or ultra-deep drawing.

The effect and mechanism of main technique among the present invention:

Thin slab continuous casting and rolling technology is adopted, rolling is carried out directly after continuous casting, the heating process is omitted, the structural layout is more perfect, the process cycle is shortened, and the investment is small; the endless rolling technology is adopted to reduce the loss of head and tail cutting , Improve production efficiency and output; adopt ferrite rolling technology, effectively reduce the rolling pressure of the rolling mill, improve the structure and material properties, save energy and reduce production costs.

Compared with the prior art, the present invention has the following advantages:

1) The use of nitrogen-controlled low-carbon/micro-carbon steel alloyed with B, Ti, Cr, Al, etc. is beneficial to increase the casting speed and control the rolling temperature, improve the structure, and reduce the aging phenomenon of hot coils; promote carbide Formation improves formability.

2) Continuous casting and rolling technology is adopted, and no roller hearth heating furnace or induction heating furnace is used to heat the slab before finishing rolling, which reduces oxidation burning loss, heating furnace fuel and energy consumption, and equipment investment, and improves metal yield. Yield and finished product rate, reducing energy consumption and investment.

3) Through the endless rolling technology, the burning loss of continuous casting flame cutting is eliminated, the head cutting rate and tail cutting rate are reduced, the yield of finished products is improved, and the rolling process is more stable; the continuous casting and rolling technology is adopted to improve the continuous casting and drawing Speed, reducing the number of rolling passes and descaling times, improving production efficiency and output.

4) Using ferrite rolling technology can reduce the generation of scale, reduce rolling pressure, save energy, improve the surface quality of strip steel, optimize microstructure and formability, etc.; adopt cooling channel control and layer cooling to achieve Precise control of finishing temperature and coiling temperature.

5) Coiling adopts a higher temperature of 710°C-580°C, which can make full use of the waste heat after rolling to realize the recovery and growth of ferrite grains, without subsequent annealing, cold rolling, etc. The thickness of the steel for punching can cover about 50% of the current thin-gauge cold-rolled sheet; at the same time, because the hot coil rolled by ferrite has good comprehensive properties, it can also be used as an ultra-thin gauge steel for deep drawing or ultra-deep drawing. Cold rolled base material.

Description of drawings

Fig. 1 is the production line flow diagram of the ferrite rolling method for low carbon steel coils used for endless continuous casting and rolling for deep drawing. In the figure: slab continuous casting machine 1, rough rolling unit 2, cooling channel 3, rolling shear 4, high-pressure water descaling device 5, finishing rolling unit 6, layer cooling device 7, high-speed flying shear 8, coiler 9 .

Fig. 2 is a temperature distribution diagram of the production line of the ferritic rolling method for the low-micro-carbon steel coil used for continuous casting and rolling for deep drawing.

Fig. 3 is a diagram showing the thickness distribution of the ferrite rolling production line for low carbon steel coils used for continuous casting and rolling for deep drawing.

Detailed ways

Example 1:

According to the chemical composition and mass percentage of low carbon steel: C: 0.06%, Si: 0.10%, Mn: 0.25%, B: 0.0003%, Ti: 0.005%, Cr: 0.01%, Als: 0.060%, P: 0.019%, S: 0.006%, N: 0.0049%, the rest is Fe and unavoidable impurities for smelting. The slab is cast in a continuous casting machine, the temperature of the continuous casting ladle is 1545°C, the casting speed is 4m/min, and the thickness of the slab is 80mm. It is directly sent to the rough rolling unit for rough rolling. The rough rolling temperature is 990°C-950°C. After rough rolling, the thickness of the intermediate billet is 7mm. The intermediate billet enters the cooling channel to control the temperature, the cooling speed is 0.3°C/s, the rolling shear head is descaled by high-pressure water, the pressure of the descaling water is 35MPa, the finishing rolling unit is finished rolling, and the finishing rolling temperature is controlled at 800°C-730°C. Lubricated rolling can be used in 3 passes, and the thickness of the finished product is 0.7mm. The layer cooling device cools, the cooling speed is 1°C/s, the high-speed flying shear is divided into coils according to the coil weight, the coiling temperature is controlled at 710°C, and then natural cooling or slow cooling to room temperature can be used. The performance meets the requirements of deep drawing, the tensile strength is 395MPa, the elongation is 36%, the n value is 0.18, and the r value is 0.8.

Example 2:

According to the chemical composition and mass percentage of low carbon steel: C: 0.04%, Si: 0.06%, Mn: 0.20%, B: 0.0008%, Ti: 0.030%, Cr: 0.10%, Als: 0.042%, P: 0.013%, S: 0.014%, N: 0.0040%, and the rest is Fe and unavoidable impurities for smelting. The slab is cast in a continuous casting machine, the temperature of the continuous casting ladle is 1547°C, the casting speed is 5m/min, and the thickness of the slab is 95mm. It is directly sent to the rough rolling unit for rough rolling. The rough rolling temperature is 1000°C-960°C. After rough rolling, the thickness of the intermediate billet is 13mm. The intermediate billet enters the cooling channel to control the temperature, the cooling speed is 2°C/s, the rolling shear head is descaled by high-pressure water, the pressure of the descaling water is 33MPa, the finishing rolling unit is finished rolling, and the finishing rolling temperature is controlled at 810°C-740°C. Lubricated rolling can be used in 2 passes, and the thickness of the finished product is 1.5mm. The layer cooling device cools, the cooling speed is 8°C/s, the high-speed flying shear is divided into coils according to the coil weight, the coiling temperature is controlled at 670°C, and then natural cooling or slow cooling to room temperature can be used. The performance meets the requirements of deep drawing, the tensile strength is 350MPa, the elongation is 39%, the n value is 0.20, and the r value is 1.0.

Example 3:

According to the chemical composition and mass percentage of micro-carbon steel: C: 0.018%, Si: 0.03%, Mn: 0.15%, B: 0.0015%, Ti: 0.012%, Cr: 0.25%, Als: 0.025%, P: 0.010%, S: 0.009%, N: 0.0031%, and the rest is Fe and unavoidable impurities for smelting. The slab is cast in a continuous casting machine, the temperature of the continuous casting ladle is 1550°C, the casting speed is 6m/min, and the thickness of the slab is 110mm. It is directly sent to the rough rolling unit for rough rolling. The rough rolling temperature is 1100°C-970°C. After rough rolling, the thickness of the intermediate billet is 20mm. The intermediate billet enters the cooling channel to control the temperature, the cooling speed is 4°C/s, the rolling shear head is descaled by high-pressure water, the descaling water pressure is 33MPa, the finishing rolling unit is finished rolling, the finishing rolling temperature is controlled at 825°C-755°C, and finally 1 pass can be lubricated and rolled, and the thickness of the finished product is 2.5mm. The layer cooling device cools, the cooling speed is 17°C/s, the high-speed flying shear is divided into coils according to the coil weight, the coiling temperature is controlled at 625°C, and then natural cooling or slow cooling to room temperature can be adopted. The performance meets the requirements of deep drawing, the tensile strength is 310MPa, the elongation is 42%, the n value is 0.22, and the r value is 1.3.

Example 4:

According to the chemical composition and mass percentage of micro-carbon steel: C: 0.008%, Si: 0.01%, Mn: 0.06%, B: 0.0020%, Ti: 0.021%, Cr: 0.18%, Als: 0.011%, P: 0.006%, S: 0.001%, N: 0.0025%, and the rest is Fe and unavoidable impurities for smelting. The slab is cast in a continuous casting machine, the temperature of the continuous casting ladle is 1555°C, the casting speed is 7m/min, and the thickness of the slab is 130mm. It is directly sent to the rough rolling unit for rough rolling. The rough rolling temperature is 1020°C-980°C. After rough rolling, the thickness of the intermediate billet is 25mm. The intermediate billet enters the cooling channel to control the temperature, the cooling speed is 6°C/s, the rolling shear head is descaled by high-pressure water, the descaling water pressure is 33MPa, the finishing rolling unit is finished rolling, the finishing rolling temperature is controlled at 850°C-770°C, and the finished product The thickness is 4mm. The layer cooling device cools, the cooling speed is 25°C/s, the high-speed flying shear is divided into coils according to the coil weight, the coiling temperature is controlled at 580°C, and then natural cooling or slow cooling to room temperature can be used. The performance meets the requirements of deep drawing, the tensile strength is 270MPa, the elongation is 45%, the n value is 0.25, and the r value is 1.5.

Example 5:

According to the chemical composition and mass percentage of low carbon steel: C: 0.03%, Si: 0.02%, Mn: 0.10%, B: 0.0002%, Ti: 0.016%, Cr: 0.06%, Als: 0.032%, P: 0.012%, S: 0.003%, N: 0.0035%, and the rest is Fe and unavoidable impurities for smelting. The slab is cast in a continuous casting machine, the temperature of the continuous casting ladle is 1550°C, the casting speed is 5.5m/min, and the thickness of the slab is 100mm. It is directly sent to the rough rolling unit for rough rolling. The rough rolling temperature is 1010°C-970°C. After rough rolling, the thickness of the intermediate billet is 15mm. The intermediate billet enters the cooling channel to control the temperature, the cooling speed is 1°C/s, the rolling shear head is descaled by high-pressure water, the descaling water pressure is 33MPa, the finishing rolling unit is finished rolling, the finishing rolling temperature is controlled at 820°C-740°C, and the finished product The thickness is 1.8mm. The layer cooling device cools, the cooling speed is 15°C/s, the high-speed flying shear is divided into coils according to the coil weight, the coiling temperature is controlled at 650°C, and then natural cooling or slow cooling to room temperature can be used. The performance meets the requirements of deep drawing, the tensile strength is 290MPa, the elongation is 43%, the n value is 0.21, and the r value is 1.1.

Claims (6)

1. A ferrite rolling method for low-carbon steel coils for endless continuous casting and deep drawing, characterized in that: the chemical composition and mass percentage of the low-carbon/micro-carbon steel are: C: 0.008— 0.06%, Si≤0.10%, Mn≤0.25%, B≤0.0020%, Ti≤0.030%, Cr≤0.25%, Als: 0.010—0.060%, P≤0.020%, S≤0.015%, N≤0.005%, The rest is Fe and unavoidable impurities; The technological process of the production line is continuous casting into billets → rough rolling by rough rolling mill → temperature control in cooling channel → descaling by high pressure water → ferrite rolling by finishing mill → cooling by layer cooling device → high-speed flying shear coiling → coiling by coiler . 2. the ferrite rolling method of a low-micro-carbon steel coil for endless continuous casting and rolling deep drawing according to claim 1, characterized in that: the endless casting and rolling technology is adopted, and the casting speed is 4m /min—7m/min, the thickness of the slab is 80mm—130mm, the thickness of the intermediate billet is 7mm—25mm, and the thickness of the finished product is 0.7mm—4mm. 3. A ferritic rolling method for low-micro-carbon steel coils for endless continuous casting and rolling deep drawing according to claim 1, characterized in that: the ferritic rolling technology is adopted, and the roughing mill operates at 1020°C Rolling is carried out in the austenite temperature zone of -950°C; the finishing rolling unit is rolled in the austenite and ferrite two-phase zone or ferrite zone rolling of 850°C -730°C; the temperature control of the cooling channel is to ensure The finish rolling temperature is hit to achieve good deep drawing performance in ferritic rolling, the cooling rate is ≤6°C/s, and air cooling or air cooling is adopted; the layer cooling device is used to ensure that the coiling temperature is hit, and the cooling rate is ≤ 25°C/s; coiling temperature 710°C-580°C is to use the waste heat after rolling to realize ferrite recovery and growth. 4. a kind of ferritic rolling method of low carbon steel coil for continuous casting and rolling deep drawing according to claim 1, it is characterized in that: in order to further improve hot coil surface quality and reduce rolling force, finish The rolling unit is lubricated and rolled; in order to ensure the descaling effect, the pressure of the descaling water is ≥30MPa. 5. The ferrite rolling method of a low-micro-carbon steel coil for endless continuous casting and rolling for deep drawing according to claim 1, characterized in that: the performance of the low-micro-carbon steel coil for deep drawing produced by the method meets the requirements of anti- Tensile strength 270MPa-400MPa, elongation ≥ 35%, n value 0.18-0.25, r value 0.8-1.5, can be directly used as steel for deep drawing; or as cold rolling of ultra-thin gauge steel for deep drawing or ultra-deep drawing Binder. 6. A ferrite rolling device for low-micro-carbon steel coils for endless continuous casting and rolling deep drawing, characterized in that the rolling device consists of a slab continuous casting machine (1), a roughing rolling unit (2), a cooling channel (3), rolling shears (4), high-pressure water descaling device (5), finishing mill (6), layer cooling device (7), high-speed flying shear (8), coiler (9), each Parts are connected sequentially.