WO2021052429A1 - 一种薄规格花纹钢板/带及其制造方法 - Google Patents

一种薄规格花纹钢板/带及其制造方法 Download PDF

Info

Publication number
WO2021052429A1
WO2021052429A1 PCT/CN2020/115957 CN2020115957W WO2021052429A1 WO 2021052429 A1 WO2021052429 A1 WO 2021052429A1 CN 2020115957 W CN2020115957 W CN 2020115957W WO 2021052429 A1 WO2021052429 A1 WO 2021052429A1
Authority
WO
WIPO (PCT)
Prior art keywords
strip
thin
steel plate
steel
gauge
Prior art date
Application number
PCT/CN2020/115957
Other languages
English (en)
French (fr)
Inventor
吴建春
Original Assignee
宝山钢铁股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宝山钢铁股份有限公司 filed Critical 宝山钢铁股份有限公司
Publication of WO2021052429A1 publication Critical patent/WO2021052429A1/zh

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/04—Making ferrous alloys by melting
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B1/24—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process
    • B21B1/26—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length in a continuous or semi-continuous process by hot-rolling, e.g. Steckel hot mill
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B45/00—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills
    • B21B45/02—Devices for surface or other treatment of work, specially combined with or arranged in, or specially adapted for use in connection with, metal-rolling mills for lubricating, cooling, or cleaning
    • B21B45/0203—Cooling
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/008—Heat treatment of ferrous alloys containing Si
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21B—ROLLING OF METAL
    • B21B1/00—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations
    • B21B1/22—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length
    • B21B2001/225—Metal-rolling methods or mills for making semi-finished products of solid or profiled cross-section; Sequence of operations in milling trains; Layout of rolling-mill plant, e.g. grouping of stands; Succession of passes or of sectional pass alternations for rolling plates, strips, bands or sheets of indefinite length by hot-rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/009—Pearlite

Definitions

  • the invention belongs to a continuous casting process and product in the metallurgical industry, and specifically relates to a thin-gauge pattern steel plate/belt and a manufacturing method thereof.
  • Traditional thin strip steel is mostly produced by continuous rolling of cast billets with a thickness of 70-200mm through multiple passes.
  • the traditional hot rolling process is: continuous casting + billet reheating and heat preservation + rough rolling + finishing rolling + cooling + Coiling, that is, firstly obtain a cast slab with a thickness of about 200mm through continuous casting. After reheating and holding the cast slab, rough rolling and finishing rolling are performed to obtain a steel strip with a thickness generally greater than 2mm, and finally the steel strip is processed Laminar cooling and coiling complete the entire hot rolling production process. If you want to produce steel strips with a thickness of less than 1.5mm (inclusive), the difficulty is relatively large, and the hot-rolled steel strips are usually subjected to subsequent cold rolling and annealing to complete. In addition, the long process flow, high energy consumption, many units and equipment, and high capital construction costs result in high production costs.
  • the thin slab continuous casting and rolling process is: continuous casting + slab heat preservation and soaking + hot continuous rolling + cooling + coiling.
  • the main difference between this process and the traditional process is that the thickness of the cast slab in the thin slab process is greatly reduced to 50-90mm. Because the cast slab is thin, the cast slab only needs to undergo 1 to 2 passes of rough rolling (the thickness of the cast slab is 70-90mm When the thickness of the cast slab is 50mm, the thickness of the continuous casting slab in the traditional process must be repeatedly rolled to reduce the thickness to the required specifications before the finish rolling; and the thin slab casting process is not necessary to go through rough rolling (when the thickness of the cast slab is 50mm).
  • the billet directly enters the soaking furnace for soaking and heat preservation, or a small amount of temperature compensation, so the thin slab process greatly shortens the process flow, reduces energy consumption, reduces investment, and reduces production costs.
  • the faster cooling rate of thin slab continuous casting and rolling the strength of the steel will increase and the yield ratio will increase, thereby increasing the rolling load, so that the thickness specification of the hot-rolled product can be economically produced and the thickness specification is not too thin, generally ⁇ 1.5mm, see Chinese patents CN200610123458.1, CN200610035800.2 and CN200710031548.2.
  • ESP all-headless thin slab continuous casting and rolling process
  • slab flame cutting and heating furnace for heat preservation and soaking and slab transition are eliminated, and the length of the entire production line is greatly shortened to about 190 meters.
  • the slab casted by the continuous casting machine The thickness is 90-110mm, and the width is 1100-1600mm.
  • the continuously cast slab passes through a section of induction heating roller table to keep and heat the slab, and then enters rough rolling, finishing rolling, layer cooling, and coiling in turn.
  • the hot-rolled sheet is obtained through the process.
  • the thinnest hot-rolled sheet of 0.8mm thickness can be obtained by this process, which expands the specification range of the hot-rolled sheet, and its single production line output can reach 2.2 million t/year scale.
  • the process has been rapidly developed and promoted.
  • the shorter process flow than thin slab continuous casting and rolling is the thin strip continuous casting and rolling process.
  • the thin strip continuous casting technology is a cutting-edge technology in the field of metallurgy and materials research. Its appearance has brought a revolution to the steel industry. It changes the production process of steel strip in the traditional metallurgical industry, integrating continuous casting, rolling, and even heat treatment into a whole, so that the produced thin strip will be formed into thin steel strip at one time after one online hot rolling.
  • the production process is simplified and the production cycle is shortened.
  • the length of the process line is only about 50m; the equipment investment is also reduced, and the product cost is significantly reduced. It is a low-carbon and environmentally friendly hot-rolled thin strip production process.
  • the twin-roll thin strip continuous casting process is a main form of the thin strip continuous casting process, and it is also the world's only industrialized thin strip continuous casting process.
  • the typical process flow of twin-roll thin strip continuous casting is shown in Figure 1.
  • the molten steel in the ladle 1 is directly poured into one by two through the ladle nozzle 2, the tundish 3, the immersion nozzle 4 and the distributor 5
  • the molten steel solidifies on the rotating circumferential surfaces of the crystallizing rollers 8a, 8b to form a solidified shell and gradually grow, and then in the two A steel strip 11 with a thickness of 1-5 mm is formed at the smallest gap (nip point) of the crystallizing roller.
  • the steel strip is fed into the rolling mill 13 through the guide plate 9 and guided to the pinch roll 12 to be rolled into a thin strip of 0.7-2.5 mm, and then passed through the cooling device 14 is cooled, after being cut by the flying shear device 16, it is finally sent to the coiler 19 to be wound into a roll.
  • Checkered plate is a hot-rolled steel plate with a pattern on the surface. As a special hot-rolled strip product, it is widely used in construction, machinery manufacturing, automobiles, bridges, transportation, shipbuilding and other fields. Its market demand is relatively high. The market demand for large, especially thin-sized checkered plates is greater.
  • the extremely thin gauge ( ⁇ 1.5mm) checkered plate has high requirements on the rolling stability of the rolling mill and the coil shape of the coiler, there are fewer domestic manufacturers, which directly leads to the market price of thin gauge hot-rolled checkered plate than the thickness of 2.0
  • the price above mm is 120-200 yuan/ton higher.
  • Its product types mainly include round bean-shaped checkered board, diamond-shaped checkered board and lentil-shaped checkered board.
  • the lentil-shaped checkered board is a checkered board for its wear resistance, beautiful appearance, non-slip, no oil and water, easy to clean and saving steel.
  • the main bean shape, the application occasions and the market demand are large, and the price is high. Now it has become a high value-added benefit variety and typical product for hot strip rolling enterprises, and major steel mills are competing for development and production.
  • the surface quality of the strip steel is very high. Generally, it is required that the thinner the thickness of the scale on the surface of the strip, the better. This requires the control of the generation of scale in the subsequent stages of the strip. For example, in the typical process of twin-roll thin strip continuous casting, the crystallizing rolls and the entrance of the rolling mill Using a closed chamber device to prevent oxidation of the cast strip, adding hydrogen in the closed chamber device such as US Patent US6920912 and controlling the oxygen content of less than 5% in US Patent US20060182989, can control the thickness of the oxide scale on the surface of the cast strip.
  • thin strip continuous casting generally has the problems of uneven structure, low elongation, high yield ratio, and poor formability.
  • the cast strip has austenite crystals.
  • the grains have obvious non-uniformity, which will cause the final product structure obtained after austenite transformation to be non-uniform, resulting in unstable product performance. Therefore, the use of thin strip continuous casting production lines to produce high-strength and thin-spec pattern plates is difficult and has certain challenges. It is impossible to copy the traditional composition process to produce, and it requires a breakthrough in composition and process.
  • the purpose of the present invention is to provide a thin-gauge patterned steel plate/strip and a manufacturing method thereof, which can eliminate complicated intermediate processes such as slab heating and multiple-pass repeated hot rolling, and pass double-roll thin strip continuous casting + one-pass online hot rolling
  • the process the production process is shorter, the efficiency is higher, the investment cost of the production line and the production cost are greatly reduced; the hot-rolled thin-gauge pattern steel plate/strip produced by the process of the present invention does not need to undergo further rolling, and can be directly supplied to the market.
  • Improve the cost performance of sheet and strip materials which can be widely used in construction, machinery manufacturing, automobiles, bridges, transportation, shipbuilding and other fields.
  • the invention selectively adds B and other microalloying elements to the steel; in the smelting process, the basicity of the slag, the type and melting point of the inclusions in the steel, the free oxygen content in the molten steel, and the acid-soluble aluminum Als content are controlled during the smelting process; Thin strip continuous casting casts strip steel with a thickness of 1.5-3mm. After the strip steel exits the crystallizing roll, it directly enters a lower closed chamber with a non-oxidizing atmosphere, and enters the on-line rolling mill for hot rolling under airtight conditions; The rolled steel strip adopts gas atomization cooling method to cool the strip steel.
  • the gas atomization cooling method can effectively reduce the thickness of the oxide scale on the surface of the steel strip, improve the temperature uniformity of the steel strip, and improve the surface quality of the steel strip.
  • the final produced steel coils can be used directly as hot-rolled checkered plates/strips, or they can be used as finishing checkered plates/strips after trimming and flattening.
  • the thin-gauge pattern steel plate/belt of the present invention has the following chemical composition weight percentages: C: ⁇ 0.06%, Si ⁇ 0.5%, Mn ⁇ 1.7%, P ⁇ 0.04%, S ⁇ 0.007%, N: 0.004-0.010%, Als: ⁇ 0.001%, B: 0.001-0.006%, total oxygen [O] T : 0.007-0.020%, Mn/S ⁇ 250; the balance is Fe and other unavoidable impurities.
  • the weight percentage of the chemical composition of the thin-gauge pattern steel plate/belt of the present invention is: C: 0.02-0.06%, Si: 0.1-0.5%, Mn: 0.4-1.7%, P ⁇ 0.04%, S ⁇ 0.007% , N: 0.004-0.010%, Als: ⁇ 0.001%, B: 0.001-0.006%, total oxygen [O]T: 0.007-0.020%, Mn/S ⁇ 250; the balance is Fe and other unavoidable impurities.
  • Mn/S in the thin-gauge pattern steel plate/belt of the present invention, Mn/S>250.
  • the grain height h of the pattern steel plate/belt of the present invention reaches more than 20% of the thickness a of the substrate belt, that is, h ⁇ 0.2a.
  • the microstructure of the patterned steel plate/belt is a mixed microstructure of massive ferrite+acicular ferrite+pearlite.
  • the yield strength of the patterned steel plate/belt is ⁇ 235MPa, the tensile strength is ⁇ 340MPa, and the elongation rate is ⁇ 26%.
  • the thickness of the patterned steel plate/belt of the present invention is 0.8-2.5mm, preferably the thickness is 1.0-1.6mm.
  • composition design of the thin-gauge pattern steel plate/belt of the present invention is the composition design of the thin-gauge pattern steel plate/belt of the present invention:
  • C is the most economical and basic strengthening element in steel. It improves the strength of steel through solid solution strengthening and precipitation strengthening. C is an essential element for the precipitation of cementite during austenite transformation. Therefore, the level of C content determines the strength level of steel to a large extent, that is, a higher C content corresponds to a higher strength level.
  • the interstitial solid solution and precipitation of C have great harm to the plasticity and toughness of steel, and the excessively high C content is detrimental to the welding performance, so the C content cannot be too high, and the strength of the steel can be compensated by adding alloy elements appropriately .
  • casting in the peritectic reaction zone is prone to slab surface cracks, and breakout accidents may occur in severe cases.
  • the C content range used in the present invention is ⁇ 0.06%. In some embodiments, the C content is 0.02-0.06%.
  • Si plays a solid solution strengthening effect in steel, and the addition of Si to steel can improve steel purity and deoxidation, but excessive Si content will lead to deterioration of weldability and toughness of the welding heat-affected zone. Therefore, the Si content range used in the present invention is ⁇ 0.5%. In some embodiments, the Si content is 0.1-0.5%.
  • Mn is one of the cheapest alloying elements. It can improve the hardenability of steel and has a considerable solid solubility in steel. It can improve the strength of steel through solid solution strengthening, and at the same time, it can basically improve the plasticity and toughness of steel. No damage, it is the most important strengthening element to increase the strength of steel, and it can also play a role in deoxidizing steel. However, excessive Mn content will cause deterioration of weldability and toughness of the welding heat-affected zone. Therefore, the range of Mn content used in the present invention is ⁇ 1.7%. In some embodiments, the Mn content is 0.4-1.7%.
  • P High content of P is easy to segregate in grain boundaries, increase the cold brittleness of steel, deteriorate welding performance, reduce plasticity, and deteriorate cold bending performance.
  • the solidification and cooling rate of the cast strip is extremely fast, which can effectively inhibit the segregation of P, thereby effectively avoiding the disadvantages of P and giving full play to the advantages of P. Therefore, in the present invention, a higher P content than the traditional production process is adopted, the content of P element is appropriately relaxed, and the dephosphorization process is eliminated in the steelmaking process. In actual operation, there is no need to deliberately perform the dephosphorization process, and no additional process is required. Add phosphorus, the range of P content is less than or equal to 0.04%.
  • S Under normal circumstances, S is a harmful element in steel, causing steel to produce hot brittleness, reducing the ductility and toughness of steel, and causing cracks during rolling. S also reduces welding performance and corrosion resistance. Therefore, in the present invention, S is also controlled as an impurity element, and its content range is ⁇ 0.007%. In some embodiments, the range of S content is controlled to be ⁇ 0.0067%. And, Mn/S ⁇ 250. In some embodiments, Mn/S>250.
  • N Similar to the C element, the N element can improve the strength of the steel through interstitial solid solution.
  • the present invention uses the effect of N and B in the steel to generate the precipitated phase of BN, which requires a certain amount of N in the steel.
  • the interstitial solid solution of N has great harm to the plasticity and toughness of steel.
  • the existence of free N will increase the yield ratio of steel, so the N content cannot be too high.
  • the range of N content used in the present invention is 0.004-0.010%.
  • B The significant effect of B in steel is: a very small amount of B can double the hardenability of steel, and B can preferentially precipitate coarse BN particles in high-temperature austenite, thereby inhibiting the precipitation of fine AlN and weakening the fineness
  • the pinning effect of AlN on the grain boundary improves the growth ability of the grains, thereby coarsening and homogenizing the austenite grains, which is conducive to the recrystallization after rolling. After the austenite grains are coarsened and homogenized, there is also It is conducive to the improvement of the yield ratio of the product and the forming performance of the product; in addition, the combination of B and N can effectively prevent the appearance of the low-melting-point phase B 2 O 3 at the grain boundary.
  • B is a lively and easily segregated element, which is easy to segregate in the grain boundary.
  • the B content is generally controlled very strictly, generally around 0.001-0.003%; while in the thin strip continuous casting process, solidification and cooling The speed is faster, which can effectively inhibit the segregation of B and solid-solve more B content, so the B content can be appropriately relaxed; it can also be controlled by a reasonable process to generate coarse BN particles, inhibit the precipitation of fine AlN, and achieve nitrogen fixation effect. Therefore, in the present invention, a higher B content than the traditional process is used, and the range is 0.001-0.006%.
  • the method for manufacturing thin-gauge patterned steel plate/belt of the present invention includes the following steps:
  • the molten steel forms a 1.5-3mm thick cast strip at the smallest gap between the two crystallizing rolls; the diameter of the crystallizing roll is between 500-1500mm, preferably 800mm, and the inside of the crystallizing roll is cooled by water.
  • the casting speed is 60-150m/min; the continuous casting flow adopts a two-stage molten steel distribution flow system, namely the tundish + flow distributor;
  • the temperature of the casting belt is between 1420 and 1480 °C, and it enters the lower closed chamber directly.
  • the lower closed chamber is filled with non-oxidizing gas.
  • the oxygen concentration in the lower closed chamber is controlled at ⁇ 5%.
  • the casting belt at the exit of the lower closed chamber The temperature is between 1150-1300°C;
  • the cast strip is sent to the rolling mill via pinch rolls in the lower enclosed chamber and rolled into a pattern plate with a thickness of 0.8-2.5mm.
  • the rolling temperature is 1100-1250°C, and the hot rolling reduction rate is controlled to 10-50%.
  • the hot rolling The rolling reduction rate is 30-50%, and the thickness of the steel strip after hot rolling is 0.8-2.5mm, preferably 1.0-1.6mm;
  • the cooling adopts gas atomization cooling method, and the cooling rate is 20-100°C/s;
  • the cooled hot-rolled steel strip is coiled into coils, and the coiling temperature is controlled to be 600-700°C.
  • the molten steel smelting adopts electric furnace steelmaking, or converter steelmaking, or enters the refining process of LF furnace, VD/VOD furnace, and RH furnace for composition adjustment.
  • the non-oxidizing gas includes CO 2 gas obtained by sublimation of N 2 , Ar or dry ice.
  • the rolls used for the patterned steel plate/plate rolling include an upper roll and a lower roll.
  • the upper roll is a patterned roll and the lower roll is a flat roll; the surface of the patterned roll is lentil-shaped, and the upper patterned roll
  • the roll diameter is 0.3-3mm larger than that of the bottom roll flat roll.
  • the roll diameter at the center of the lower roll flat roll is 0.15-0.22mm smaller than the roll diameters at both ends, and forms a smooth transition parabola Roll shape.
  • the gas-water ratio of the gas atomization cooling is 15:1-10:1, the air pressure is 0.5-0.8 MPa, and the water pressure is 1.0-1.5 MPa.
  • air-water ratio refers to the flow ratio of compressed air and water, and the unit of flow is m 3 /h.
  • step 5 at the patterned steel plate/belt atomized cooling outlet, 1-2 pairs of nozzles for blowing high-pressure side air jets for purging the accumulated water on the patterned steel plate/belt surface, the nozzle pressure is 0.5-0.8MPa, and the flow rate 20-200m 3 /h.
  • the coiling adopts a double-coiler form, or adopts a Carrousel winding form.
  • the cooled hot-rolled steel strip is directly coiled into a coil after the poor quality head is removed.
  • MnO-SiO 2 -Al 2 O 3 ternary inclusions As shown in the shaded area in Figure 2, MnO-SiO 2 -Al 2 O 3 ternary inclusions
  • the MnO/SiO 2 in the composition is controlled within 0.5-2, preferably 1-1.8.
  • O in steel is an essential element for the formation of oxidized inclusions.
  • the present invention requires the formation of low-melting ternary inclusions of MnO-SiO 2 -Al 2 O 3 , which requires steel
  • the free oxygen [O] Free range in water is: 0.0005 to 0.005%.
  • a double-roll thin strip continuous caster is used to cast a metal casting strip with a thickness of 1.5-3mm.
  • the temperature of the casting belt is 1420-1480°C, and it enters the lower closed chamber directly.
  • the lower closed chamber is filled with non-oxidizing gas, such as CO 2 gas obtained by sublimation of dry ice.
  • the oxygen concentration in the lower closed chamber is controlled. In ⁇ 5%.
  • the lower airtight chamber protects the cast strip from oxidation to the entrance of the rolling mill.
  • the temperature of the casting strip at the outlet of the lower closed chamber is between 1150-1300°C.
  • thermodynamic equations of boron and nitrogen, aluminum and nitrogen in ⁇ -Fe in steel are as follows:
  • the initial precipitation temperature of BN in steel is about 1280°C
  • the precipitation of BN tends to balance at 980°C
  • the precipitation of AlN has just begun (the precipitation temperature of AlN is about 980°C).
  • the precipitation of BN has priority over AlN.
  • the invention completes the combination of B and N in the lower closed chamber to generate coarse BN particles, thereby inhibiting the precipitation of fine AlN, weakening the pinning effect of fine AlN on grain boundaries, improving the growth ability of grains, and thereby coarsening austenite
  • the grains make the austenite grains more uniform, which is beneficial to effectively reduce the yield ratio of the product and improve the product performance; in addition, the combination of B and N can effectively prevent the appearance of the low melting point phase B 2 O 3 at the grain boundary.
  • the pattern roll used for the pattern plate is the upper roll, and its surface is lentil-shaped.
  • the diameter of the pattern roll of the upper roll should be larger than that of the flat roll of the lower roll.
  • the diameter is 0.3-3mm larger.
  • the pattern roller has no shape, in order to ensure the shape of the pattern plate after rolling and avoid the generation of intermediate waves, when making the bottom roll flat roll, take the centerline of the roll body as the reference, and the roll diameter at the center is larger than the roll diameter at both ends. Smaller than 0.15-0.22mm, and form a smooth transition parabolic roller shape. Due to the higher rolling temperature of the present invention, the pattern height h can reach 20% or more of the substrate strip thickness a, that is, h ⁇ 0.2a.
  • the strip steel after online hot rolling is cooled after rolling, and the cooling adopts the gas atomization cooling method to cool the strip steel.
  • the gas atomization cooling method can effectively reduce the thickness of the oxide scale on the surface of the strip, improve the uniformity of the temperature of the strip, and increase Surface quality of strip steel.
  • the gas-water ratio of gas atomization cooling is 15:1 ⁇ 10:1, the air pressure is 0.5 ⁇ 0.8MPa, and the water pressure is 1.0 ⁇ 1.5MPa.
  • high-pressure water mist is sprayed on the surface of the steel strip. On the one hand, it can reduce the temperature of the steel strip. On the other hand, the water mist will form a dense gas film covering the surface of the steel strip, which can prevent the strip from being oxidized.
  • This cooling method can avoid the problems caused by traditional spraying or laminar cooling, make the surface temperature of the strip drop uniformly, improve the uniformity of the strip temperature, and achieve the effect of homogenizing the internal microstructure; at the same time, the uniform cooling can improve the strip The shape quality and performance stability of the steel; effectively reduce the thickness of the oxide scale on the surface of the strip.
  • the cooling rate of gas atomization cooling is in the range of 20-100°C/s.
  • the convex pattern on the upper surface of the patterned steel plate Due to the convex pattern on the upper surface of the patterned steel plate, it is easy to have water on the upper surface after cooling.
  • the nozzle pressure is 0.5-0.8MPa, and the flow rate is 20. -200m 3 /h, used to purge the accumulated water on the surface of the tread plate.
  • the cooled hot-rolled steel strip is cut by the cutting head to remove the poor quality head, and then directly coiled into a coil.
  • the coiling temperature is controlled to be 600-700°C, so that the high-temperature austenite structure after rolling is transformed into a mixed microstructure of massive ferrite + acicular ferrite + pearlite.
  • Figure 4 is a physical view of the pattern plate produced by the present invention.
  • the most obvious feature of the present invention which is different from the existing thin strip continuous casting technology is the roll diameter of the crystallizing roll and the corresponding flow distribution method.
  • the technical feature of EUROSTRIP is ⁇ 1500mm large diameter crystallizing roller, large crystallizing roller, large molten steel capacity in molten pool, easy flow distribution, high cost of crystallizing roller manufacturing and operation and maintenance.
  • the technical feature of CASTRIP is the ⁇ 500mm small diameter crystallizing roller, the crystallizing roller is small, the molten steel volume is small, and the flow distribution is very difficult, but the cost of manufacturing and operation and maintenance of the casting machine is low.
  • CASTRIP adopts a three-stage molten steel distribution flow system (tundish + transition bag + flow distributor).
  • the use of a three-stage flow distribution system directly leads to an increase in the cost of refractory materials; more importantly, the three-stage flow distribution system makes the path of molten steel flow longer and the temperature drop of molten steel is also greater.
  • the tapping temperature needs to be greatly increased. The increase in the tapping temperature will cause problems such as increased steelmaking costs, increased energy consumption, and shortened life of refractory materials.
  • a crystallizing roller with a roller diameter of ⁇ 800mm preferably adopts a two-stage molten steel distribution and flow distribution system (tundish + flow distributor).
  • the molten steel flowing out of the distributor forms different distribution patterns along the roller surface and the two end surfaces, and flows in two paths without interfering with each other. Due to the use of a two-stage flow distribution system, compared with a three-stage flow system, the cost of refractory materials is greatly reduced; the shortening of the molten steel flow path reduces the temperature drop of the molten steel, which can lower the tapping temperature, compared with the three-stage flow system , The tapping temperature can be reduced by 30-50°C.
  • the lowering of the tapping temperature can effectively reduce the cost of steelmaking, save energy and extend the life of refractory materials.
  • the invention is matched with a crystallizing roller with a roller diameter of ⁇ 800mm and adopts a two-stage molten steel distribution system, which not only realizes the requirement of stable molten steel distribution, but also realizes the goals of simple structure, convenient operation and low processing cost.
  • Chinese patent CN107716552A discloses a method for producing a pattern plate with a thickness of 1.4mm by using a CSP process.
  • the method adopts a CSP short-flow production line to produce thin-gauge pattern plates, with a weight reduction rate of not less than 10% and excellent plate shape quality.
  • the invention adopts a more advanced thin strip continuous casting and rolling process, which can realize the production of checkered plates with the thinnest thickness of 1.0 mm.
  • Chinese patent CN108486476A discloses a 700Mpa vanadium-containing hot-rolled pattern steel plate and a production method thereof.
  • This patent uses the traditional hot rolling process to produce higher-strength microalloyed checkered plate products, with a thickness ranging from 1.5 to 8.0 mm, which cannot achieve continuous production of ultra-thin batch sizes, and continuous production is difficult.
  • the invention adopts the thin strip continuous casting process to produce, and the product thickness, strength level and process realization mode are all obviously different.
  • the document “Trial Rolling and Process Improvement of Thin Gauge Checkered Plates” mainly solves the process problem of 2.3mm thick checkered plates, and does not involve the process and thickness specifications of the present invention.
  • the document “Research and Application of New Technology for Rolling Extreme Thin-gauge Checkered Plates”, the thickness of the thin-gauge checkered plates mainly produced by the ESP short-flow process is about 1.8mm, and a relatively satisfactory result has been obtained, but it is related to the process route of the present invention. And thickness specifications are also different.
  • the present invention adopts thin strip continuous casting technology to reasonably add trace element boron (B) to steel to produce thin-gauge patterned steel plates/belts, which has not been reported so far.
  • the present invention eliminates the need for complicated processes such as slab heating and multi-pass repeated hot rolling.
  • double-roll thin strip continuous casting + one-pass online hot rolling process the production process is shorter, the efficiency is higher, and the investment cost of the production line is reduced. The production cost is greatly reduced.
  • the present invention omits many complicated intermediate steps in the traditional production process. Compared with the traditional patterned steel plate/belt production process, the energy consumption and CO 2 emissions of production are greatly reduced, and it is a green and environmentally friendly product.
  • the present invention adopts the thin strip continuous casting process to produce hot-rolled thin-gauge patterned steel plates/strips.
  • the thickness of the cast strip itself is relatively thin.
  • a small amount of boron is added to preferentially precipitate coarse BN particles in high-temperature austenite, thereby inhibiting the precipitation of fine AlN, weakening the pinning effect of fine AlN on grain boundaries, improving the growth ability of grains, and thus The homogenization of austenite grains is conducive to improving the performance of the product.
  • the present invention adopts the strip steel gas atomization cooling method after rolling, which can avoid the problems caused by traditional spraying or laminar cooling, so that the surface temperature of the strip can be uniformly reduced, and the uniformity of the strip temperature can be improved, thereby achieving uniform internal microcosmic
  • uniform cooling can improve the shape quality and performance stability of the strip steel; effectively reduce the thickness of the oxide scale on the surface of the strip steel.
  • the precipitation of alloying elements occurs during the cooling process of the traditional slab, and the utilization rate of the alloying elements is often reduced due to insufficient re-dissolution of the alloying elements when the slab is reheated.
  • the high-temperature cast strip is directly hot-rolled, and the added alloy elements mainly exist in a solid solution state, which can improve the alloy utilization rate.
  • the low-cost, thin-spec pattern plate product produced by the present invention due to the characteristics of rapid solidification of thin strip continuous casting, has guaranteed strength, and can meet the current market demand for lightweight (weight reduction) of this type of product, and at the same time It can effectively save material costs for downstream users; if the product is used in mobile applications such as automobiles and ships, lightweighting can also bring these users advantages such as saving fuel or electricity consumption (new energy vehicles) and reducing exhaust emissions.
  • the present invention uses a hot-rolled steel strip Carrousel coiler, which effectively shortens the length of the production line; at the same time, co-coiling can greatly improve the control accuracy of the coiling temperature and improve the stability of product performance.
  • Figure 1 is a schematic diagram of the process layout of the twin-roll thin strip continuous casting process
  • Figure 2 is a ternary phase diagram of MnO-SiO 2 -Al 2 O 3 (shaded area: low melting point area);
  • Figure 3 is a schematic diagram of the thermodynamic curves of BN and AlN precipitation
  • Figure 4 is a physical view of the pattern plate produced by the present invention.
  • Fig. 5 is a schematic diagram of the thickness of the substrate and the pattern of the steel plate of the present invention.
  • the molten steel designed in accordance with the chemical composition of the present invention is directly poured in a large ladle 1, through a ladle nozzle 2, a tundish 3, an immersion nozzle 4, and a distributor 5, which can rotate relatively quickly and quickly
  • the molten steel solidifies on the rotating circumferential surface of the crystallizing rollers 8a, 8b, and then forms a solidified shell and gradually grows on the two crystallizing rollers.
  • a 1.5-3mm thick cast belt 11 is formed at the smallest gap (nip point); the diameter of the crystallizing roller of the present invention is between 500-1500mm, preferably 800mm; the inside of the crystallizing roller is cooled by water. Depending on the thickness of the casting strip, the casting speed of the casting machine is between 60-150m/min.
  • the temperature of the casting belt 11 is 1420-1480°C, and it directly enters the lower closed chamber 10, and the lower closed chamber 10 is protected by inert gas to protect the strip from oxidation.
  • the atmosphere for the anti-oxidation protection can be N 2 , Ar, or other non-oxidizing gases, such as CO 2 gas obtained by sublimation of dry ice.
  • the oxygen concentration in the lower closed chamber 10 is controlled to be less than 5%.
  • the lower airtight chamber 10 protects the cast strip 11 from oxidation to the entrance of the rolling mill 13.
  • the temperature of the cast strip at the outlet of the lower closed chamber 10 is between 1150-1300°C.
  • the cast strip is sent to the hot rolling mill 13 through the swing guide plate 9, the pinch roll 12, and the roller table 15.
  • a gas atomization rapid cooling device 14 Cooling by gas atomization cooling method to improve strip temperature uniformity.
  • the cutting head falls into the flying shear pit 18 along the flying shear guide plate 17, and the hot-rolled strip after the cutting head enters the coiler 19 for coiling.
  • the steel coil is removed from the coiler, it is naturally cooled to room temperature.
  • the final produced steel coils can be used directly as hot-rolled checkered plates/strips, or they can be used as finishing checkered plates/strips after trimming and flattening.
  • the rolls used for hot rolling include an upper roll and a lower roll.
  • the upper roll is a patterned roll and the lower roll is a flat roll; the surface of the patterned roll is lentil-shaped; the diameter of the upper patterned roll is 0.3-3mm larger than the diameter of the lower flat roll .
  • the roller diameter at the center of the lower roller flat roller is 0.15-0.22mm smaller than the diameter of the two ends of the roller, and forms a smoothly transitional parabolic roller shape.
  • the chemical composition of the embodiment of the present invention is shown in Table 1, and the balance of the composition is Fe and other unavoidable impurities.
  • the process parameters are shown in Table 2, and the properties of the hot-rolled strip finally obtained are shown in Table 3.
  • the performance yield strength of the final thin-gauge pattern steel plate/belt produced by the thin strip continuous casting process technology according to the steel grade composition design range provided by the present invention reaches 235MPa or more, the tensile strength reaches 340MPa or more, and the elongation reaches More than 26%, cold working bending performance is qualified, can be widely used in construction, machinery manufacturing, automobiles, bridges, transportation, shipbuilding and other fields.
  • Table 1 The chemical composition of the example steel (wt.%)
  • Example 1 0.03 0.13 1.35 0.008 0.004 0.0077 0.0093 0.0009 0.004
  • Example 2 0.04 0.10 0.90 0.013 0.003 0.0051 0.0110 0.0006 0.001
  • Example 3 0.02 0.24 1.28 0.015 0.004 0.0059 0.0150 0.0004 0.003
  • Example 4 0.05 0.36 1.10 0.023 0.004 0.0088 0.0130 0.0008 0.005
  • Example 5 0.03 0.44 0.65 0.009 0.002 0.0054 0.0120 0.0007 0.004
  • Example 6 0.05 0.42 0.67 0.012 0.002 0.0048 0.0070 0.0008 0.005
  • Example 7 0.06 0.28 0.85 0.015 0.003 0.0040 0.0100 0.0005 0.004
  • Example 8 0.02 0.17 1.00 0.014 0.004 0.0100 0.0085 0.0006 0.003
  • Example 9 0.03 0.26 0.84 0.018 0.003 0.0068 0.0200 0.0003 0.004
  • Example 10 0.04 0.44 0.40 0.040 0.001 0.0065 0.0125 0.0004 0.006
  • Example 11 0.50 0.65 0.030 0.002 0.0080 0.0090 0.0005 0.004
  • Example 12 0.02 0.27 1.70 0.022 0.0067 0.0075 0.0118 0.0003 0.002
  • Example 13 0.06 0.48 1.37 0.038 0.004 0.0065 0.0132 0.0006 0.006
  • Example 14 0.045 0.23 1.40 0.017 0.003 0.0064 0.0075 0.0005 0.004
  • the invention adopts a thin strip continuous casting process to produce thin-gauge checkered plates. Due to the thin thickness, the thin strip continuous casting process has strong manufacturing and cost advantages for thin-gauge hot-rolled high-strength products with a thickness of less than 1.5 mm (inclusive).
  • the characteristic thickness of the thin-gauge checkered plate directly supplied in the hot-rolled state is 1.0-1.6mm. Due to the thin thickness of the product, the traditional production line technology is used to produce the product, and the product cannot be produced due to the shape problem of the product; the thin slab is used to connect Casting and rolling process to produce, the roll consumption of the roll is also significantly increased, such a production process will undoubtedly increase the production cost of thin-gauge pattern plates. Therefore, the use of thin strip continuous casting technology to produce thin-gauge pattern plate products can not only meet the market's demand for thin-gauge and lightweight, but also reduce production costs and improve product profitability and competitiveness.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Continuous Casting (AREA)
  • Metal Rolling (AREA)

Abstract

一种薄规格花纹钢板/带及其制造方法，在钢中有选择地添加B等微合金元素；冶炼过程中控制渣的碱度、钢中夹杂物类型、熔点、钢水中的游离氧含量及酸溶铝Als含量；然后进行双辊薄带连铸浇铸出1.5-3mm厚的带钢（11），在带钢（11）出结晶辊（8a、8b）后，直接进入到一个有非氧化性气氛的下密闭室（10）中，并在密闭情况下进入到在线轧机（13）进行热轧；轧制后采用气雾化冷却方式对带钢（11）进行冷却，可有效减小表面氧化皮厚度、改善温度均匀性及提高表面质量。最后生产的钢卷可以直接作为热轧花纹板/带使用，也可以经过切边-平整后作为精整花纹板/带使用，可广泛应用于建筑、机械制造、汽车、桥梁、交通、造船等领域。

Description

一种薄规格花纹钢板/带及其制造方法 技术领域
本发明属于冶金行业连铸工艺和产品，具体涉及一种薄规格花纹钢板/带及其制造方法。
背景技术
传统的薄带钢大都是由厚达70-200mm的铸坯经过多道次连续轧制生产出来的，传统热轧工艺流程是：连铸+铸坯再加热保温+粗轧+精轧+冷却+卷取，即首先通过连铸得到厚度为200mm左右的铸坯，对铸坯进行再加热并保温后，再进行粗轧和精轧，得到厚度一般大于2mm的钢带，最后对钢带进行层流冷却和卷取，完成整个热轧生产过程。如果要生产厚度小于1.5mm(含)的钢带，则难度相对较大，通常要对热轧钢带进行后续冷轧以及退火来完成。且工艺流程长、能耗高、机组设备多、基建成本高，导致生产成本较高。
薄板坯连铸连轧工艺流程是：连铸+铸坯保温均热+热连轧+冷却+卷取。该工艺与传统工艺的主要区别是：薄板坯工艺的铸坯厚度大大减薄，为50-90mm，由于铸坯薄，铸坯只要经过1～2道次粗轧(铸坯厚度为70-90mm时)或者不需要经过粗轧(铸坯厚度为50mm时)，而传统工艺的连铸坯要经过反复多道次轧制，才能减薄到精轧前所需规格；而且薄板坯工艺的铸坯不经冷却，直接进入均热炉进行均热保温，或者少量补温，因此薄板坯工艺大大缩短了工艺流程，降低了能耗，减少了投资，从而降低了生产成本。但薄板坯连铸连轧由于较快的冷速会导致钢材强度提高，屈强比提高，从而增加轧制载荷，使得可经济地生产热轧产品的厚度规格也不可能太薄，一般为≥1.5mm，见中国专利CN200610123458.1，CN200610035800.2以及CN200710031548.2。
近年来兴起的一种全无头薄板坯连铸连轧工艺(简称：ESP)，是在上述半无头薄板坯连铸连轧工艺的基础上发展起来的一种改进工艺，ESP实现了板坯连铸的无头轧制，取消了板坯火焰切割和起保温均热、板坯过渡作用的加热炉，整条产线 长度大大缩短到190米左右，连铸机连铸出来的板坯厚度在90-110mm，宽度在1100-1600mm，连铸出来的板坯通过一段感应加热辊道对板坯起到保温均热的作用，然后再依次进入粗轧、精轧、层冷、卷取工序得到热轧板，这种工艺由于实现了无头轧制，可以得到最薄0.8mm厚度的热轧板，拓展了热轧板的规格范围，再加上其单条产线产量可达220万t/年规模。目前该工艺得到了快速发展和推广，目前世界上已有多条ESP产线在运营生产。
比薄板坯连铸连轧更短的工艺流程是薄带连铸连轧工艺，薄带连铸技术是冶金及材料研究领域内的一项前沿技术，它的出现为钢铁工业带来一场革命，它改变了传统治金工业中钢带的生产过程，将连续铸造、轧制、甚至热处理等整合为一体，使生产的薄带坯经过一道次在线热轧就一次性形成薄钢带，大大简化了生产工序，缩短了生产周期，其工艺线长度仅50m左右；设备投资也相应减少，产品成本显著降低，是一种低碳环保的热轧薄带生产工艺。双辊薄带连铸工艺是薄带连铸工艺的一种主要形式，也是世界上唯一实现产业化的一种薄带连铸工艺。
双辊薄带连铸典型的工艺流程如图1所示，大包1中的熔融钢水通过大包长水口2、中间包3、浸入式水口4以及布流器5直接浇注在一个由两个相对转动并能够快速冷却的结晶辊8a、8b和侧封装置6a、6b围成的熔池7中，钢水在结晶辊8a、8b旋转的周向表面凝固形成凝固壳并逐渐生长，进而在两结晶辊辊缝隙最小处(nip点)形成1-5mm厚的钢带11，钢带经由导板9导向夹送辊12送入轧机13中轧制成0.7-2.5mm的薄带，随后经过冷却装置14冷却，经飞剪装置16切头后，最后送入卷取机19卷取成卷。
面对钢铁企业严峻的市场形势，扩展产品结构，提高经济效益和竞争力是企业生存发展的唯一出路，各大钢厂需要生产出更具竞争力的产品。花纹板是一种表面带有花纹的热轧钢板，它作为一种特殊的热轧板带产品，被广泛应用于建筑、机械制造、汽车、桥梁、交通、造船等领域，其市场需求量较大，尤其是薄规格花纹板的市场需求量更大。由于极薄规格(≤1.5mm)花纹板对于轧机的轧制稳定性和卷取机卷形上要求很高，因此国内生产厂家较少，直接导致了薄规格热轧花纹板市场价格比厚度2.0mm以上的价格高出120-200元/吨。其产品类型主要有圆豆形花纹板、菱形花纹板和扁豆形花纹板等，扁豆形花纹板以其耐磨、美观、防滑、不存油水、易于清洁及节约钢材等特点，而成为花纹板的主要豆形，应用场合和市场需求 量大、价格较高，如今已经成为热连轧企业的高附加值效益品种和典型性产品，各大钢厂均在竞相开发与生产。
热轧带钢作为薄规格热轧板产品使用时，对带钢表面质量要求很高。一般要求带钢表面氧化皮的厚度越薄越好，这就需要在铸带后续的各个阶段控制氧化铁皮的生成，如在双辊薄带连铸的典型工艺中，在结晶辊直至轧机入口均采用密闭室装置防止铸带氧化，在密闭室装置内如美国专利US6920912添加氢气以及在美国专利US20060182989中控制氧气含量小于5％，均可以控制铸带表面的氧化皮厚度。但是在轧机至卷取这段输送过程如何控制氧化皮的厚度很少有关专利涉及，尤其是在采用层流冷却或喷淋冷却对带钢进行冷却的过程中，高温的带钢与冷却水接触，铸带表面的氧化皮厚度增长很快。同时，高温的带钢与冷却水接触还会带来很多问题：其一，会在带钢表面形成水斑(锈斑)，影响表面质量；其二，层流冷却或喷淋冷却用的冷却水容易造成带钢表面局部冷却不均匀，造成带钢内部微观组织的不均匀，从而造成带钢性能的不均匀，影响产品质量；其三，带钢表面局部冷却不均匀，会造成板形的恶化，影响板形质量。
但是，薄带连铸由于其本身的快速凝固工艺特性，生产的钢种普遍存在组织不均匀、延伸率偏低、屈强比偏高、成型性不好的问题；同时铸带奥氏体晶粒具有明显不均匀性，会导致奥氏体相变后所获得的最终产品组织也不均匀，从而导致产品的性能不稳定。因此采用薄带连铸生产线来生产高强薄规格花纹板，具有一定难度，具有一定的挑战，照搬传统的成分工艺是无法生产的，需要在成分和工艺上有突破。
发明内容
本发明的目的在于提供一种薄规格花纹钢板/带及其制造方法，可以省去板坯加热、多道次反复热轧等复杂中间过程，通过双辊薄带连铸+一道次在线热轧工序，生产流程更短、效率更高，产线投资成本和生产成本大幅降低；采用本发明工艺生产的热轧薄规格花纹钢板/带，不需要经过进一步轧制，可直接供给市场使用，显著提高板带材的性价比，可广泛应用于建筑、机械制造、汽车、桥梁、交通、造船等领域。
为达到上述目的，本发明的技术方案是：
本发明在钢中有选择地添加B等微合金元素；冶炼过程中通过控制渣的碱度、 钢中夹杂物类型及熔点、钢水中的游离氧含量、酸溶铝Als含量；然后进行双辊薄带连铸浇铸出1.5-3mm厚的带钢，在带钢出结晶辊后，直接进入到一个有非氧化性气氛的下密闭室中，并在密闭情况下进入到在线轧机进行热轧；轧制后的带钢采用气雾化冷却方式对带钢进行冷却，气雾化冷却方式可以有效减小带钢表面氧化皮厚度，改善带钢温度均匀性，提高带钢表面质量。最后生产的钢卷可以直接作为热轧花纹板/带使用，也可以经过切边-平整后作为精整花纹板/带使用。
具体的，本发明所述的薄规格花纹钢板/带，其化学成分重量百分比为：C：≤0.06％，Si≤0.5％，Mn≤1.7％，P≤0.04％，S≤0.007％，N：0.004-0.010％，Als：<0.001％，B：0.001-0.006％，总氧[O] T：0.007-0.020％，Mn/S≥250；余量为Fe和其他不可避免杂质。
优选地，本发明所述薄规格花纹钢板/带的化学成分重量百分比为：C：0.02-0.06％，Si：0.1-0.5％，Mn：0.4-1.7％，P≤0.04％，S≤0.007％，N：0.004-0.010％，Als：<0.001％，B：0.001-0.006％，总氧[O]T：0.007-0.020％，Mn/S≥250；余量为Fe和其他不可避免杂质。
在一些实施方案中，本发明所述薄规格花纹钢板/带中，Mn/S＞250。
本发明所述花纹钢板/带的纹高h达到基板带厚a的20％以上，即h≥0.2a。
所述花纹钢板/带的微观组织为块状铁素体+针状铁素体+珠光体混合微观组织。所述花纹钢板/带的屈服强度≥235MPa，抗拉强度≥340MPa，延伸率≥26％。
优选地，本发明所述花纹钢板/带的厚度为0.8-2.5mm，优选厚度为1.0-1.6mm。
在本发明薄规格花纹钢板/带的成分设计中：
C：C是钢中最经济、最基本的强化元素，通过固溶强化和析出强化来提高钢的强度。C是奥氏体转变过程中析出渗碳体必不可少的元素，因此C含量的高低在很大程度上决定钢的强度级别，即较高的C含量对应较高的强度级别。但是，由于C的间隙固溶和析出对钢的塑性和韧性有较大危害，而且，过高的C含量对焊接性能不利，因此C含量不能过高，钢的强度通过适当添加合金元素来弥补。同时，对常规板坯连铸来说，在包晶反应区浇铸易产生铸坯表面裂纹，严重时会发生漏钢事故。对薄带连铸来说也同样如此，在包晶反应区浇铸铸带坯易发生表面裂纹，严重时会发生断带。因此，Fe-C合金的薄带连铸同样需要避开包晶反应区。故本发明采用的C含量范围是≤0.06％。在一些实施方案中，C含量为0.02-0.06％。
Si：Si在钢中起固溶强化作用，且钢中加Si能提高钢质纯净度和脱氧，但Si含量过高会导致可焊性和焊接热影响区韧性恶化。故本发明采用的Si含量范围是≤0.5％。在一些实施方案中，Si含量为0.1-0.5％。
Mn：Mn是价格最便宜的合金元素之一，它能提高钢的淬透性，在钢中具有相当大的固溶度，通过固溶强化提高钢的强度，同时对钢的塑性和韧性基本无损害，是提高钢的强度最主要的强化元素，还可以在钢中起到脱氧的作用。但Mn含量过高会导致可焊性和焊接热影响区韧性恶化。故本发明采用的Mn含量范围是≤1.7％。在一些实施方案中，Mn含量为0.4-1.7％。
P：高含量的P容易在晶界偏析，增加钢的冷脆性，使焊接性能变坏，降低塑性，使冷弯性能变坏。在薄带连铸工艺中，铸带的凝固和冷却速率极快，可有效抑制P的偏析，从而可有效避免P的劣势，充分发挥P的优势。故在本发明中，采用较传统工艺生产时高的P含量，适当放宽P元素的含量，炼钢工序中取消脱磷工序，在实际操作中，不需要刻意进行脱磷工序，也不需要额外添加磷，P含量的范围≤0.04％。
S：在通常情况下S是钢中有害元素，使钢产生热脆性，降低钢的延展性和韧性，在轧制时造成裂纹。S还会降低焊接性能和耐腐蚀性。故在本发明中，S也作为杂质元素来控制，其含量范围是≤0.007％。在一些实施方案中，S含量范围控制为≤0.0067％。且，Mn/S≥250。在一些实施方案中，Mn/S＞250。
Als：为控制钢中的夹杂物，本发明要求不能用Al脱氧，耐材的使用中，也应尽量避免Al的额外引入，要求酸溶铝Als的含量：<0.001％。
N：与C元素类似，N元素可通过间隙固溶提高钢的强度，本发明要利用钢中的N跟B作用生成BN的析出相，需要钢中有一定的N含量。但是，N的间隙固溶对钢的塑性和韧性有较大危害，自由N的存在会提高钢的屈强比，因此N含量也不能过高。本发明采用的N含量范围是0.004-0.010％。
B：B在钢中的显著作用是：极微量的B就可以使钢的淬透性成倍增加，B可以在高温奥氏体中优先析出粗大的BN颗粒从而抑制细小AlN的析出，减弱细小AlN对晶界的钉扎作用，提高晶粒的生长能力，从而粗化和均匀化奥氏体晶粒，有利于轧制后的再结晶，奥氏体晶粒粗化均匀化以后，也有利于产品屈强比的改善，可提高产品的成形性能；另外B与N的结合可以有效防止晶界低熔点相B 2O 3的出 现。
B是活泼易偏析元素，容易在晶界偏聚，传统工艺生产含B钢时，B含量一般控制的非常严格，一般在0.001-0.003％左右；而在薄带连铸工艺中，凝固和冷却速率较快，可有效抑制B的偏析，固溶更多的B含量，因此B的含量可以适当放宽；还可以通过合理的工艺控制生成粗大的BN颗粒，抑制细小的AlN析出，起到固氮的作用。故在本发明中，采用较传统工艺更高的B含量，范围是0.001-0.006％。
本发明所述的薄规格花纹钢板/带的制造方法，其包括如下步骤：
1)冶炼
按上述成分进行冶炼，炼钢过程造渣的碱度a＝CaO/SiO 2(质量比)控制在a<1.5，优选a<1.2，或a＝0.7-1.0；钢水中获得低熔点MnO-SiO 2-Al 2O 3三元夹杂物中的MnO/SiO 2(质量比)控制在0.5～2，优选为1～1.8；钢水中的自由氧[O] Free含量为：0.0005-0.005％；钢水中Mn和S的控制须满足如下关系式：Mn/S≥250；
2)连铸
采用双辊薄带连铸，钢水在两结晶辊辊缝隙最小处形成1.5-3mm厚的铸带；结晶辊直径在500-1500mm之间，优选为800mm，结晶辊内部通水冷却，铸机的浇铸速度为60-150m/min；连铸布流采用两级钢水分配布流系统，即中间包+布流器；
3)下密闭室保护
铸带出结晶辊后，铸带温度在1420-1480℃，直接进入到下密闭室内，下密闭室内通非氧化性气体，下密闭室内的氧浓度控制在<5％，下密闭室出口铸带的温度在1150-1300℃；
4)在线热轧
铸带在下密闭室内经夹送辊送至轧机，轧制成0.8-2.5mm厚度的花纹板，轧制温度为1100-1250℃，控制热轧压下率为10-50％，优选地，热轧压下率为30-50％，热轧后钢带的厚度为0.8-2.5mm，优选厚度为1.0-1.6mm；
5)轧后冷却
对在线热轧后的带钢进行轧后冷却，冷却采用气雾化冷却方式，冷却速率为20-100℃/s；
6)带钢卷取
冷却后的热轧带钢卷取成卷，控制卷取温度为600-700℃。
优选的，步骤1)中，钢水冶炼采用电炉炼钢，或转炉炼钢，或再进入LF炉、VD/VOD炉、RH炉精炼工序，进行成分调整。
优选的，步骤3)中，所述非氧化性气体包括N 2、Ar或干冰升华得到的CO 2气体。
优选的，步骤4)中，花纹钢板/板轧制用的轧辊包括上辊、下辊，上辊为花纹辊，下辊为平辊；花纹辊的表面形貌为扁豆形，上辊花纹辊辊径比下辊平辊辊径大0.3-3mm。
优选的，步骤4)中，以所述下辊平辊辊身的中心线为基准，所述下辊平辊中心处辊径比两端辊径小0.15-0.22mm，并形成平滑过渡的抛物线辊形。
优选的，步骤5)中，气雾化冷却的气水比为15：1～10：1，气压0.5～0.8MPa，水压1.0～1.5MPa。本文中，气水比指压缩空气和水的流量比，流量的单位为m 3/h。
优选的，步骤5)中，在花纹钢板/带雾化冷却出口，设置1-2对用以吹扫花纹钢板/带表面的积水的高压侧喷气的喷嘴，喷嘴压力0.5～0.8MPa，流量20-200m 3/h。
优选的，步骤6)中，卷取采用双卷取机形式，或采用卡罗塞尔卷取形式。
优选的，步骤6)中，冷却后的热轧带钢经切除质量较差的头部后，直接进行卷取成卷。
在本发明制造方法中：
为提高薄带连铸钢水的可浇铸性，炼钢过程造渣的碱度a＝CaO/SiO 2控制在a<1.5，优选a<1.2，或a＝0.7-1.0。
为提高薄带连铸钢水的可浇铸性，需要获得低熔点MnO-SiO 2-Al 2O 3三元夹杂物，如图2的阴影区域，MnO-SiO 2-Al 2O 3三元夹杂物中的MnO/SiO 2控制在0.5～2，优选1～1.8。
为提高薄带连铸钢水的可浇铸性，钢中的O是形成氧化夹杂物的必要元素，本发明需要形成低熔点的MnO-SiO 2-Al 2O 3的三元夹杂物，要求钢水中的自由氧[O] Free范围为：0.0005-0.005％。
为提高薄带连铸钢水的可浇铸性，上述成分中，Mn和S的控制须满足如下关系式：Mn/S≥250。
用双辊式薄带连铸机浇注厚度1.5-3mm的金属铸带。在铸带出结晶辊后，铸带温度在1420-1480℃，直接进入到下密闭室内，下密闭室通非氧化性气体，比如干 冰升华得到的CO 2气体等，下密闭室内的氧浓度控制在<5％。下密闭室对铸带的防氧化保护到轧机入口。下密闭室出口铸带的温度在1150-1300℃。
铸带在下密闭过程中涉及到的BN析出相的理论基础：
钢中硼与氮、铝和氮在γ-Fe中的热力学方程如下：
BN＝B+N；Log[B][N]＝-13970/T+5.24    (1)
AlN＝Al+N；Log[Al][N]＝-6770/T+1.03    (2)
如图3所示，钢中BN的开始析出温度在1280℃左右，980℃时BN的析出趋于平衡，而此时AlN的析出才刚刚开始(AlN的析出温度在980℃左右)，从热力学上讲，BN的析出要优先于AlN。本发明在下密闭室内完成B与N的结合，生成粗大的BN颗粒，从而抑制了细小的AlN析出，减弱细小AlN对晶界的钉扎作用，提高晶粒的生长能力，从而粗化奥氏体晶粒，使奥氏体晶粒更加均匀，有利于有效降低产品的屈强比，改善产品性能；另外B与N的结合可以有效防止晶界低熔点相B 2O 3的出现。
花纹板所用的轧辊，花纹辊为上辊，其表面形貌为扁豆形，为保证轧后带钢不粘辊，确保出带的稳定性，上辊花纹辊辊径应比下辊平辊辊径大0.3-3mm。由于花纹辊无辊形，为保证轧后花纹板的板形，避免中间浪的产生，下辊平辊制作时，以该辊辊身的中心线为基准，中心处辊径比两端辊径小0.15-0.22mm，并形成平滑过渡的抛物线辊形。由于本发明较高的轧制温度，花纹板纹高h可以达到基板带厚a的20％及以上，即h≥0.2a。
对在线热轧后的带钢进行轧后冷却，冷却采用气雾化冷却方式对带钢进行冷却，气雾化冷却方式可以有效减小带钢表面氧化皮厚度，改善带钢温度均匀性，提高带钢表面质量。气雾化冷却的气水比为15：1～10：1，气压0.5～0.8MPa，水压1.0～1.5MPa。气雾化后形成高压水雾喷射在钢带表面，一方面起到了降低钢带温度的作用，另一方面水雾会形成致密的气膜包覆在带钢表面，起到带钢防氧化的作用，从而有效控制了热轧带钢表面氧化皮的生长。该种冷却方式可以避免传统喷淋或者层流冷却带来的问题，使带钢表面温度均匀下降，提高带钢温度均匀性，从而达到均匀化内部微观组织的效果；同时冷却均匀，可以提高带钢的板形质量和性能稳定性；有效减少带钢表面的氧化皮厚度。气雾化冷却的冷却速率范围为20-100℃/s。
由于花纹钢板上表面有凸起的花纹，在冷却后上表面容易有积水存在，在带钢 雾化冷却出口，设置1-2对高压侧喷气的喷嘴，喷嘴压力0.5～0.8MPa，流量20-200m 3/h，用以吹扫花纹板表面的积水。
冷却后的热轧带钢经切头剪切除质量较差的头部后，直接进行卷取成卷。控制卷取温度为600-700℃，使轧后的高温奥氏体组织转变为块状铁素体+针状铁素体+珠光体混合微观组织。
经过上述制造过程，最终的薄规格花纹钢板/带的性能屈服强度达到235MPa以上，抗拉强度达到340MPa以上，延伸率达到26％以上。图4为本发明生产的花纹板实物图。
本发明与已有技术的区别和改进之处：
本发明区别于现有薄带连铸技术最明显的一个特征就是结晶辊的辊径及其相对应的布流方式。EUROSTRIP技术特征就是Φ1500mm大辊径结晶辊，结晶辊大、熔池钢水容量大，布流容易，结晶辊制造及运维成本高。CASTRIP技术特征就是Φ500mm小辊径结晶辊，结晶辊小、熔池钢水容量小，布流非常困难，但铸机设备制造与运维成本低。CASTRIP为解决小熔池的均匀布流问题，采用三级钢水分配布流系统(中间包+过渡包+布流器)。由于采用了三级布流系统，会直接导致耐材成本增加；更为主要的是，三级布流系统使钢水流动的路径变长，钢水的温降也较大，为了满足熔池钢液的温度，出钢温度需要大大提高。出钢温度的提高，会导致炼钢成本增加、能耗增加以及耐材寿命缩短等问题。
本发明优选Φ800mm辊径的结晶辊，采用两级钢水分配布流系统(中间包+布流器)。从布流器流出的钢水，沿辊面和两个端面形成不同的布流模式，且分两路流动，互不干扰。由于采用了两级布流系统，相比三级布流系统，耐材成本大幅度降低；钢水流动路径的缩短，使钢水温降减小，可以降低出钢温度，相比三级布流系统，出钢温度可降低30-50℃。出钢温度的降低，可有效降低炼钢成本、节约能耗以及延长耐材寿命。本发明配合优选Φ800mm辊径的结晶辊，采用两级钢水分配布流系统，既实现了钢水稳定布流的要求，又实现了结构简单、操作方便、加工成本低的目标。
现有的薄带连铸生产薄带材产品和工艺的专利有很多，但采用薄带连铸生产含B的薄规格花纹钢板/带，还未见直接报导，但在产品工艺控制和设备上认为有以下几篇专利/文献和本专利具有一定可比性，详述如下：
中国专利CN107716552A公开了一种用CSP流程生产厚度为1.4mm花纹板的方法。该方法采用CSP短流程生产线生产薄规格花纹板，减重率不低于10％、板形质量优良。本发明采用更为先进的薄带连铸连轧工艺，可实现最薄厚度更加薄可达1.0mm的花纹板生产。
中国专利CN108486476A公开了一种700Mpa含钒热轧花纹钢板及其生产方法。该专利采用传统热轧工艺流程来生产更高强度的微合金化花纹板产品，其厚度范围为1.5-8.0mm，无法实现批量超薄规格的持续生产，连续化生产难度较大。本发明采用薄带连铸工艺生产，产品厚度、强度级别及工艺实现方式均明显不同。
文献《薄规格花纹板试轧与工艺改进》，主要解决2.3mm厚的花纹板的工艺问题，未涉及本发明的工艺及厚度规格。文献《极限薄规格花纹板轧制新技术研究与应用》，其采用ESP短流程工艺主要生产的薄规格花纹板厚度在1.8mm左右，取得了较为满意的结果，但与本发明涉及的工艺路线及厚度规格也均有差异。
本发明的主要优点在于：
1.本发明采用薄带连铸技术，在钢中合理添加微量元素硼(B)来生产薄规格花纹钢板/带，迄今为止尚未见报导。
2.本发明省去了板坯加热、多道次反复热轧等复杂过程，通过双辊薄带连铸+一道次在线热轧工序，生产流程更短、效率更高，产线投资成本和生产成本大幅降低。
3.本发明省去了传统工艺生产中诸多复杂的中间步骤，与传统花纹钢板/带生产过程相比，生产的能耗和CO 2排放大幅度降低，是一种绿色环保的产品。
4.本发明采用薄带连铸工艺生产热轧薄规格花纹钢板/带，铸带厚度本身较薄，通过在线热轧至期望产品厚度，薄规格产品的生产不需要经过进一步轧制，直接供给市场使用，达到薄规格热轧板供货的目的，可以显著提高板带材的性价比。
5.本发明采用添加微量的硼元素，在高温奥氏体中优先析出粗大的BN颗粒从而抑制细小AlN的析出，减弱细小AlN对晶界的钉扎作用，提高晶粒的生长能力，从而粗化、均匀化奥氏体晶粒，有利于改善产品的性能。
6.本发明采用轧后带钢气雾化冷却方式，可以避免传统喷淋或者层流冷却带来的问题，使带钢表面温度均匀下降，提高带钢温度均匀性，从而达到均匀化内部微观组织的效果；同时冷却均匀，可以提高带钢的板形质量和性能稳定性；有效减 少带钢表面的氧化皮厚度。
7.传统工艺板坯冷却过程中发生合金元素析出，板坯再加热时往往会由于合金元素回溶不充分而降低合金元素利用率。本发明薄带连铸工艺中，高温铸带直接热轧，所添加的合金元素主要以固溶态存在，可提高合金利用率。
8.本发明生产出的低成本、薄规格的花纹板产品，由于薄带连铸快速凝固的特征，强度有保证，可以满足目前市场上对该类产品轻量化(减重)的需求，同时可以为下游用户有效节约用料成本；假如产品被使用于汽车、轮船等移动的场合，则轻量化还可以为这些用户带来节约燃油或电耗(新能源汽车)、减少尾气排放等优势。
9.本发明选用热轧钢带卡罗塞尔卷取机，有效缩短产线长度；同时同位卷取可以大大提高卷取温度的控制精度，提高产品性能的稳定性。
附图说明
图1为双辊薄带连铸工艺的工艺布置示意图；
图2为MnO-SiO 2-Al 2O 3三元相图(阴影区域：低熔点区)；
图3为BN，AlN析出的热力学曲线示意图；
图4为本发明生产的花纹板实物图；
图5为本发明钢板的基板厚度和花纹厚度示意图。
具体实施方式
下面用实施例对本发明作进一步阐述，但这些实施例绝非对本发明有任何限制。本领域技术人员在本说明书的启示下对本发明实施中所作的任何变动都将落在本发明权利要求保护范围内。
参见图1，将符合本发明化学成分设计的钢水经大包1，通过大包长水口2、中间包3、浸入式水口4以及布流器5直接浇注在一个由两个相对转动并能够快速冷却的结晶辊8a、8b和侧封板装置6a、6b围成的熔池7中，钢水在结晶辊8a、8b旋转的周向表面凝固，进而形成凝固壳并逐渐生长随后在两结晶辊辊缝隙最小处(nip点)形成1.5-3mm厚的铸带11；本发明所述的结晶辊直径在500-1500mm之间，优选800mm；其内部通水冷却。根据铸带厚度不同，铸机的浇铸速度范围介 于60-150m/min。
在铸带11出结晶辊8a、8b后，铸带温度在1420-1480℃，直接进入到下密闭室10内，下密闭室10通惰性气体保护带钢，实现对带钢的防氧化保护，防氧化保护的气氛可以是N 2，也可以是Ar，也可以是其他非氧化性气体，比如干冰升华得到的CO 2气体等，下密闭室10内的氧浓度控制在<5％。下密闭室10对铸带11的防氧化保护到轧机13入口。下密闭室10出口铸带的温度在1150-1300℃。然后通过摆动导板9、夹送辊12、辊道15将铸带送至热轧机13，热轧后形成0.8-2.5mm的热轧带，轧制后的带钢使用气雾化快速冷却装置14以气雾化冷却方式冷却，以改善带钢温度均匀性。经飞剪装置16切头之后，切头沿着飞剪导板17掉入飞剪坑18中，切头后的热轧带进入卷取机19进行卷取。将钢卷从卷取机上取下后，自然冷却至室温。最后生产的钢卷可以直接作为热轧花纹板/带使用，也可以经过切边-平整后作为精整花纹板/带使用。热轧用的轧辊包括上辊、下辊，上辊为花纹辊，下辊为平辊；花纹辊表面形貌为扁豆形；上辊花纹辊辊径比下辊平辊辊径大0.3-3mm。以所述下辊平辊辊身的中心线为基准，该下辊平辊中心处辊径比两端辊径小0.15-0.22mm，并形成平滑过渡的抛物线辊形。
本发明实施例化学成分如表1所示，其成分余量为Fe和其他不可避免杂质。经本发明的制造方法，工艺参数见表2，最终获得热轧带的性能见表3。
综上所述，利用薄带连铸工艺技术按本发明提供的钢种成分设计范围生产得到的最终薄规格花纹钢板/带的性能屈服强度达到235MPa以上，抗拉强度达到340MPa以上，延伸率达到26％以上，冷加工折弯性能合格，可广泛应用于建筑、机械制造、汽车、桥梁、交通、造船等领域。
表1：实施例钢的化学成分(wt.％)
  C Si Mn P S N O Als B
实施例1 0.03 0.13 1.35 0.008 0.004 0.0077 0.0093 0.0009 0.004
实施例2 0.04 0.10 0.90 0.013 0.003 0.0051 0.0110 0.0006 0.001
实施例3 0.02 0.24 1.28 0.015 0.004 0.0059 0.0150 0.0004 0.003
实施例4 0.05 0.36 1.10 0.023 0.004 0.0088 0.0130 0.0008 0.005
实施例5 0.03 0.44 0.65 0.009 0.002 0.0054 0.0120 0.0007 0.004
实施例6 0.05 0.42 0.67 0.012 0.002 0.0048 0.0070 0.0008 0.005
实施例7 0.06 0.28 0.85 0.015 0.003 0.0040 0.0100 0.0005 0.004
实施例8 0.02 0.17 1.00 0.014 0.004 0.0100 0.0085 0.0006 0.003
实施例9 0.03 0.26 0.84 0.018 0.003 0.0068 0.0200 0.0003 0.004
实施例10 0.04 0.44 0.40 0.040 0.001 0.0065 0.0125 0.0004 0.006
实施例11 0.05 0.50 0.65 0.030 0.002 0.0080 0.0090 0.0005 0.004
实施例12 0.02 0.27 1.70 0.022 0.0067 0.0075 0.0118 0.0003 0.002
实施例13 0.06 0.48 1.37 0.038 0.004 0.0065 0.0132 0.0006 0.006
实施例14 0.045 0.23 1.40 0.017 0.003 0.0064 0.0075 0.0005 0.004
表2：实施例的工艺参数
Figure PCTCN2020115957-appb-000001
表3：实施例钢的产品性能
Figure PCTCN2020115957-appb-000002
Figure PCTCN2020115957-appb-000003
本发明采用薄带连铸工艺来生产薄规格花纹板，由于厚度较薄，对于厚度小于1.5mm(含)的薄规格热轧高强产品，薄带连铸工艺具有较强的制造和成本优势。薄规格花纹板以热轧状态直接供货的产品规格特征厚度为1.0-1.6mm，由于产品厚度较薄，采用传统产线工艺来生产，会出现产品板形问题而无法生产；采用薄板坯连铸连轧工艺来生产，轧辊的辊耗也明显增大，这样的生产流程无疑增加了薄规格花纹板的生产成本。因此，采用薄带连铸工艺来生产薄规格花纹板产品，不仅可以满足市场对薄规格、轻量化的需求，还可以降低生产成本，提高产品盈利水平和竞争力。

Claims (14)

  1. 一种薄规格花纹钢板/带，其化学成分重量百分比为：C≤0.06％，Si≤0.5％，Mn≤1.7％，P≤0.04％，S≤0.007％，N：0.004-0.010％，Als：<0.001％，B：0.001-0.006％，总氧[O] T：0.007-0.020％，Mn/S≥250；余量为Fe和其他不可避免杂质。
  2. 如权利要求1所述的薄规格花纹钢板/带的制造方法，其特征是，所述薄规格花纹钢板/带的化学成分重量百分比为：C：0.02-0.06％，Si：0.1-0.5％，Mn：0.4-1.7％，P≤0.04％，S≤0.007％，N：0.004-0.010％，Als：<0.001％，B：0.001-0.006％，总氧[O] T：0.007-0.020％，Mn/S≥250；余量为Fe和其他不可避免杂质。
  3. 如权利要求1所述的薄规格花纹钢板/带的制造方法，其特征是，所述花纹钢板/带的纹高h达到基板带厚a的20％以上，即h≥0.2a。
  4. 如权利要求1或2所述的薄规格花纹钢板/带，其特征在于，所述花纹钢板/带的微观组织为块状铁素体+针状铁素体+珠光体混合微观组织。
  5. 如权利要求1或2或3所述的薄规格花纹钢板/带，其特征在于，所述花纹钢板/带的屈服强度≥235MPa，抗拉强度≥340MPa，延伸率≥26％。
  6. 如权利要求1所述的薄规格花纹钢板/带的制造方法，其特征是，所述薄规格花纹钢板/带的厚度为0.8-2.5mm，优选为1.0-1.6mm。
  7. 如权利要求1-6中任一项所述的薄规格花纹钢板/带的制造方法，其特征是，包括如下步骤：
    1)冶炼
    按权利要求1所述成分进行冶炼，炼钢过程造渣的碱度a＝CaO/SiO 2(质量比)控制在a<1.5，优选a<1.2，或a＝0.7-1.0；钢水中获得低熔点MnO-SiO 2-Al 2O 3三元夹杂物中的MnO/SiO 2(质量比)控制在0.5～2，优选为1～1.8；钢水中的自由氧[O] Free含量为：0.0005-0.005％；钢水中Mn和S的控制须满足如下关系式：Mn/S≥250；
    2)连铸
    采用双辊薄带连铸，钢水在两结晶辊辊缝隙最小处形成1.5-3mm厚的铸带；结晶辊直径在500-1500mm之间，优选为800mm，结晶辊内部通水冷却，铸机的浇铸速度为60-150m/min；连铸布流采用两级钢水分配布流系统，即中间包+布流器；
    3)下密闭室保护
    铸带出结晶辊后，铸带温度在1420-1480℃，直接进入到下密闭室内，下密闭室内通非氧化性气体，下密闭室内的氧浓度控制在<5％，下密闭室出口铸带的温度在1150-1300℃；
    4)在线热轧
    铸带在下密闭室内经夹送辊送至轧机，轧制成0.8-2.5mm厚度的花纹板，轧制温度为1100-1250℃，控制热轧压下率为10-50％，优选地，热轧压下率为30-50％，热轧后钢带的厚度为0.8-2.5mm，优选厚度为1.0-1.6mm；
    5)轧后冷却
    对在线热轧后的带钢进行轧后冷却，冷却采用气雾化冷却方式，冷却速率为20-100℃/s；
    6)带钢卷取
    冷却后的热轧带钢卷取成卷，控制卷取温度为600-700℃。
  8. 如权利要求7所述的薄规格花纹钢板/带的制造方法，其特征是，步骤1)中，钢水冶炼采用电炉炼钢，或转炉炼钢，或再进入LF炉、VD/VOD炉、RH炉精炼工序，进行成分调整。
  9. 如权利要求7所述的薄规格花纹钢板/带的制造方法，其特征是，步骤3)中，所述非氧化性气体包括N 2、Ar或干冰升华得到的CO 2气体。
  10. 如权利要求7所述的薄规格花纹钢板/带的制造方法，其特征是，步骤4)中，花纹钢板/带轧制用的轧辊包括上辊、下辊，上辊为花纹辊，下辊为平辊；花纹辊的表面形貌为扁豆形，花纹辊辊径比平辊辊径大0.3-3mm。
  11. 如权利要求10所述的薄规格花纹钢板/带的制造方法，其特征是，步骤4)中，以所述平辊辊身的中心线为基准，所述平辊中心处辊径比两端辊径小0.15-0.22mm，并形成平滑过渡的抛物线辊形。
  12. 如权利要求7所述的薄规格花纹钢板/带的制造方法，其特征是，步骤5)中，气雾化冷却的气水流量比为15：1～10：1，流量单位为m 3/h，气压0.5～0.8MPa，水压1.0～1.5MPa。
  13. 如权利要求7所述的薄规格花纹钢板/带的制造方法，其特征是，步骤5)中，在花纹钢板/带雾化冷却出口，设置1-2对用以吹扫花纹钢板/带表面的积水的高压侧喷气的喷嘴，喷嘴压力0.5～0.8MPa，流量20-200m 3/h。
  14. 如权利要求7所述的薄规格花纹钢板/带的制造方法，其特征是，步骤6)中，卷取采用双卷取机形式，或采用卡罗塞尔卷取形式。
PCT/CN2020/115957 2019-09-19 2020-09-17 一种薄规格花纹钢板/带及其制造方法 WO2021052429A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201910889368.0 2019-09-19
CN201910889368.0A CN112522566B (zh) 2019-09-19 2019-09-19 一种薄规格花纹钢板/带及其制造方法

Publications (1)

Publication Number Publication Date
WO2021052429A1 true WO2021052429A1 (zh) 2021-03-25

Family

ID=74883375

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2020/115957 WO2021052429A1 (zh) 2019-09-19 2020-09-17 一种薄规格花纹钢板/带及其制造方法

Country Status (2)

Country Link
CN (1) CN112522566B (zh)
WO (1) WO2021052429A1 (zh)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113564471A (zh) * 2021-07-16 2021-10-29 莱芜钢铁集团银山型钢有限公司 一种6-8mm薄规格Q345qE高性能桥梁钢板及其制造方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114602973B (zh) * 2022-03-14 2024-01-26 湖南华菱涟源钢铁有限公司 一种CSP短流程生产抗拉强度800MPa级极薄花纹板的方法
CN114871395B (zh) * 2022-04-20 2024-04-02 河北敬业高品钢科技有限公司 薄带连铸中设备参数的控制方法及装置
CN115401174B (zh) * 2022-09-06 2023-05-23 山东理工大学 一种用于改善结晶辊气动性能的具有流线型花纹的双辊铸挤轧系统

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08225820A (ja) * 1995-02-17 1996-09-03 Sumitomo Metal Ind Ltd 高炭素Ｓｉキルド鋼の製造方法
CN1753744A (zh) * 2003-01-24 2006-03-29 纽科尔公司 铸造具有低表面粗糙度和低孔隙率的钢带
US20060182989A1 (en) * 2005-02-15 2006-08-17 Nucor Corporation Thin cast strip with protective layer, and method for making the same
CN101177760A (zh) * 2007-11-27 2008-05-14 湖南华菱湘潭钢铁有限公司 一种高强度船用钢板及其生产方法
CN101716608A (zh) * 2009-12-30 2010-06-02 首钢总公司 一种热轧薄规格花纹板板形控制方法
CN101827668A (zh) * 2007-08-13 2010-09-08 纽科尔公司 微裂纹得到减少的薄铸钢带
CN102002628A (zh) * 2009-08-31 2011-04-06 宝山钢铁股份有限公司 一种低碳钢薄板的制造方法
CN102240675A (zh) * 2011-04-21 2011-11-16 马鞍山钢铁股份有限公司 一种应用csp工艺生产花纹钢板的方法
CN102534383A (zh) * 2012-03-01 2012-07-04 首钢总公司 高韧性海洋工程用钢板及其制造方法
CN102796943A (zh) * 2012-08-31 2012-11-28 宝山钢铁股份有限公司 一种薄壁油桶用薄带钢及其制造方法
CN103667878A (zh) * 2012-08-31 2014-03-26 宝山钢铁股份有限公司 一种薄壁油桶用薄带钢及其制造方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102199720B (zh) * 2010-03-23 2013-02-06 宝山钢铁股份有限公司 屈服强度400MPa以上级别低碳钢薄板及其制造方法
KR101245701B1 (ko) * 2010-11-15 2013-04-01 주식회사 포스코 인장강도 590ＭＰａ급의 가공성 및 재질편차가 우수한 고강도 열연 ＤＰ강의 제조방법
CN102787278B (zh) * 2012-08-31 2015-04-22 宝山钢铁股份有限公司 一种含硼耐候薄带钢及其制造方法
CN106834887B (zh) * 2016-12-30 2019-02-22 日照宝华新材料有限公司 基于esp薄板坯连铸连轧流程生产薄规格re510l钢的方法

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08225820A (ja) * 1995-02-17 1996-09-03 Sumitomo Metal Ind Ltd 高炭素Ｓｉキルド鋼の製造方法
CN1753744A (zh) * 2003-01-24 2006-03-29 纽科尔公司 铸造具有低表面粗糙度和低孔隙率的钢带
US20060182989A1 (en) * 2005-02-15 2006-08-17 Nucor Corporation Thin cast strip with protective layer, and method for making the same
CN101827668A (zh) * 2007-08-13 2010-09-08 纽科尔公司 微裂纹得到减少的薄铸钢带
CN101177760A (zh) * 2007-11-27 2008-05-14 湖南华菱湘潭钢铁有限公司 一种高强度船用钢板及其生产方法
CN102002628A (zh) * 2009-08-31 2011-04-06 宝山钢铁股份有限公司 一种低碳钢薄板的制造方法
CN101716608A (zh) * 2009-12-30 2010-06-02 首钢总公司 一种热轧薄规格花纹板板形控制方法
CN102240675A (zh) * 2011-04-21 2011-11-16 马鞍山钢铁股份有限公司 一种应用csp工艺生产花纹钢板的方法
CN102534383A (zh) * 2012-03-01 2012-07-04 首钢总公司 高韧性海洋工程用钢板及其制造方法
CN102796943A (zh) * 2012-08-31 2012-11-28 宝山钢铁股份有限公司 一种薄壁油桶用薄带钢及其制造方法
CN103667878A (zh) * 2012-08-31 2014-03-26 宝山钢铁股份有限公司 一种薄壁油桶用薄带钢及其制造方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113564471A (zh) * 2021-07-16 2021-10-29 莱芜钢铁集团银山型钢有限公司 一种6-8mm薄规格Q345qE高性能桥梁钢板及其制造方法

Also Published As

Publication number Publication date
CN112522566A (zh) 2021-03-19
CN112522566B (zh) 2022-10-21

Similar Documents

Publication Publication Date Title
WO2021052429A1 (zh) 一种薄规格花纹钢板/带及其制造方法
WO2021052315A1 (zh) 30CrMo热轧钢板/带及其生产方法
WO2021052428A1 (zh) 一种高强薄规格花纹钢板/带及其制造方法
CN112522571B (zh) 一种双辊薄带连铸生产马氏体钢带的方法
WO2021052314A1 (zh) 耐火耐候钢板/带及其制造方法
WO2021052426A1 (zh) 一种薄规格高耐蚀钢及其生产方法
CN112522580A (zh) 一种马氏体钢带及其制造方法
CN112522641B (zh) 一种高强薄规格高耐蚀钢及其制造方法
WO2021052312A1 (zh) 马氏体钢带及其制造方法
CN112522572A (zh) 一种双辊薄带连铸生产高耐蚀钢的方法
WO2021052319A1 (zh) 高强薄规格高耐蚀钢及其制造方法
CN112522575B (zh) 一种薄带连铸生产薄规格花纹钢板/带的方法
CN112522573B (zh) 一种含b马氏体钢带及其制造方法
WO2021052431A1 (zh) 一种薄带连铸高扩孔钢及其制造方法
WO2021052434A1 (zh) 一种Nb微合金化高强高扩孔钢及其生产方法
CN112522588B (zh) 一种薄带连铸生产高强薄规格花纹钢板/带的方法
CN112522577B (zh) 一种高耐蚀钢及其制造方法
CN112522633B (zh) 一种薄规格马氏体钢带及其制造方法
CN112522591B (zh) 一种薄带连铸生产高强高耐蚀钢的方法
CN112522574A (zh) 一种薄带连铸高扩孔钢及其生产方法
CN112522582B (zh) 一种含硼高强高扩孔钢及其制造方法
CN112522597B (zh) 一种含硼高扩孔钢及其生产方法
CN112522584B (zh) 一种薄带连铸高扩孔钢及其制造方法
WO2021052317A1 (zh) 一种耐硫酸露点腐蚀用热轧钢板/带及其制造方法
CN112522598A (zh) 一种高耐蚀钢及其制造方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20865410

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20865410

Country of ref document: EP

Kind code of ref document: A1