WO2015180462A1 - 由钢水直接生产免酸洗热镀薄板带产品的方法 - Google Patents

由钢水直接生产免酸洗热镀薄板带产品的方法 Download PDF

Info

Publication number
WO2015180462A1
WO2015180462A1 PCT/CN2014/094611 CN2014094611W WO2015180462A1 WO 2015180462 A1 WO2015180462 A1 WO 2015180462A1 CN 2014094611 W CN2014094611 W CN 2014094611W WO 2015180462 A1 WO2015180462 A1 WO 2015180462A1
Authority
WO
WIPO (PCT)
Prior art keywords
hot
molten steel
dip
reduction
strip
Prior art date
Application number
PCT/CN2014/094611
Other languages
English (en)
French (fr)
Inventor
李俊
谭宁
关闯
方园
马新建
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
Priority claimed from CN201410240643.3A external-priority patent/CN105220101B/zh
Priority claimed from CN201410240632.5A external-priority patent/CN105219929B/zh
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
Priority to US15/314,934 priority Critical patent/US10683561B2/en
Priority to DE112014006715.6T priority patent/DE112014006715B4/de
Priority to RU2016152000A priority patent/RU2701242C2/ru
Priority to KR1020167034950A priority patent/KR102413905B1/ko
Priority to JP2017514761A priority patent/JP6527942B2/ja
Publication of WO2015180462A1 publication Critical patent/WO2015180462A1/zh

Links

Images

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/54Furnaces for treating strips or wire
    • C21D9/56Continuous furnaces for strip or wire
    • C21D9/561Continuous furnaces for strip or wire with a controlled atmosphere or vacuum
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B21MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21BROLLING OF METAL
    • B21B1/00Metal-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
    • B21B1/46Metal-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 metal immediately subsequent to continuous casting
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/06Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0622Continuous 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
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/10Supplying or treating molten metal
    • B22D11/11Treating the molten metal
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/26Methods of annealing
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D1/00General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C21D1/76Adjusting the composition of the atmosphere
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226Hot rolling
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D8/00Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0278Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular surface treatment
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21DMODIFYING 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
    • C21D9/00Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/52Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
    • C21D9/525Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length for wire, for rods
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/06Zinc or cadmium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/04Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
    • C23C2/12Aluminium or alloys based thereon
    • CCHEMISTRY; METALLURGY
    • C23COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23CCOATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C2/00Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
    • C23C2/34Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
    • C23C2/36Elongated material
    • C23C2/40Plates; Strips

Definitions

  • the present invention relates to a method for continuously producing a hot-dip product, and more particularly to a method for directly producing a pickling-free hot-dip sheet material from molten steel.
  • the thin strip continuous casting technology Compared with the traditional plate production process, the thin strip continuous casting technology has the characteristics of short process, less capital investment, and realization of “one fire and material”, which greatly improves the energy efficiency of steel production and saves production costs.
  • the surface quality of thin strip continuous casting products is not high and generally requires subsequent processing.
  • Hot-dip galvanizing including hot-dip zinc and other alloys, is an important method for anti-oxidation and anti-corrosion of steel materials.
  • Hot-dip galvanizing products are widely used in automobiles and ships due to their remarkable protective effect, good surface quality and low cost. , construction and other industries.
  • most of the hot-dip galvanizing products on the market are produced by continuous hot-dip galvanizing production line.
  • the production cycle of this process is long, and the metal needs to pass through the slab, hot rolling, from liquid steel to continuous hot-dip galvanizing.
  • Pickling, cold rolling and other processes it is these complex processing procedures that lead to thin strip continuous casting and hot-dip galvanizing process is difficult to match, the key obstacles are from the pickling process, and the pickling process will also cause environmental damage Serious pollution and destruction.
  • the Chinese patent No. 201310489332.6 discloses a method for producing hot-rolled acid-free pickling plates by thin strip continuous casting combined with reduction annealing, and the general procedure is to cast molten steel into strips, heat-leveling and then cooling and coiling, in order to obtain For pickling products, the cast strip coils need to be re-rolled, reductively annealed, and then the finished product or hot-dip galvanized. The obtained hot-dip galvanized products are still carried out in separate lines, with many processes and lack of continuity.
  • 6,588,491 B2 discloses a method of directly producing an acid-free strip, the key step of which is to cast molten steel into a ribbon, to reduce annealing (the scale is reduced to porous iron), to mechanically brush the porous iron, to obtain acid-free Washing strip steel, as the core, through the process of adding hot rolling, cold rolling, oiling, hot-dip galvanizing, electro-galvanizing and other processes to achieve a variety of product production.
  • the disadvantage is that the metal iron produced by the reduction is mechanically brushed off, which not only increases the production process, but also reduces the metal yield and increases the production cost; in addition, the reduction is carried out at a certain temperature to reduce and then cool, as shown in FIG.
  • the main problem is that the iron oxide scale reduction rate is slow, the efficiency is low, the reduction is not complete, affecting product performance, see Figure 2 ⁇ Figure 5, the iron oxide reduction in Figure 2 Incomplete, close to the surface layer is reduced, a large amount of oxide remains on the bottom layer; Figure 3 shows the existence of large cracks on the surface after reduction of the hot rolled sheet, but the reduction efficiency is low, and a large amount of oxide on the surface can be reduced in the future; the iron oxide scale in Fig. 4 is not completely restored.
  • the oxide particles are reduced around and the center is still oxide; the reduced iron in Fig. 5 is evenly distributed on the surface, but the structure is dense and hinders the transmission of the reducing gas, affecting the reduction of the oxide in the inner layer, and ultimately leading to incomplete reduction.
  • the object of the present invention is to provide a method for directly producing a pickling-free hot-dip sheet material from molten steel, which can be combined with hot-dip production by means of pickling-free technology to realize steel from liquid steel to hot plating.
  • the product is highly continuous in production and reduces the number of processes, increasing the metal yield.
  • the present invention provides a method for directly producing a pickling-free hot-dip sheet material from molten steel, comprising the following steps:
  • Thin strip continuous casting the refined steel water is adjusted by the cooling of the ladle and the tundish in the closed molten pool by the cooling action of the twin-roll casting machine, and the mixture of the inert gas and the reducing gas is used in the casting blank. Gas protection;
  • Reductive annealing the strip is placed in a reduction annealing furnace and reduced by a mixed gas of a reducing gas and an inert gas to remove the scale formed in the previous step;
  • Hot-plating After cooling in a protective atmosphere, enter the zinc pot for hot-dip galvanizing or hot-dip other alloys, then cool and coil.
  • the hot rolling step is further included: flattening the strip at a high temperature to improve the shape of the strip, rolling to a suitable thickness to change the product specification, or mechanically breaking the scale of the strip surface, the deformation rate is 1% - 30%.
  • the deformation rate is 5%, 10% or 20%.
  • the reduction process comprises two heating and holding sections, as shown in FIG. 2, respectively, the hot-rolled sheets are subjected to sectional heating and heat preservation in the range of 450-600 ° C and 700-1000 ° C, respectively, for reducing heat.
  • the scale of the rolled sheet is iron oxide, which is reduced in the range of 1-5 minutes at 450-600 ° C and 1-3 minutes in the range of 700-1000 ° C.
  • the reducing gas is kept from the first heating section until the outlet of the cooling section, wherein the concentration of the reducing gas in each section is the same or different, and the concentration of the reducing gas in the entire reduction furnace is 5%-100%.
  • the reducing gas concentration is 5-30%.
  • the reducing gas concentration is 5%, 10% or 15%.
  • the inert gas is nitrogen or argon, and the reducing gas is hydrogen or carbon monoxide.
  • a single frame is adopted, and a blowing device is provided for intermittently or uninterruptedly introducing an inert gas into the hot rolling zone to reduce the chance of contact between the steel plate and the air, thereby reducing the surface oxidation of the steel plate.
  • the mixed gas flows in a turbulent manner in the furnace, and the moisture and hydrogen content in the mixed gas are related to the temperature.
  • the moisture content that is, the larger the ratio of hydrogen to water, the reduction efficiency of the iron oxide.
  • the lowest value of the hydrogen water ratio slightly changes, the temperature is high, and the lowest value of hydrogen to water ratio is slightly smaller.
  • the hydrogen to water ratio is at least 4.1; at 1000 ° C, the hydrogen to water ratio is at least 0.9. .
  • the average thickness of the scale of the strip surface before entering the reduction annealing furnace is controlled to be 1-5 ⁇ m.
  • the hot-dip step it is required to cool to 450-460 ° C when hot-dip galvanizing; to 590-610 ° C when hot-dip aluminum-zinc; to 680-670 ° C when hot-dip aluminum-silicon.
  • the plating layer is Zn, Zn-Al, Zn-Al-Mg, Zn-Al-Mg-Si, or an Al-Si alloy.
  • alloying oiling, embossing, coating, or direct molding can be performed.
  • the method for directly producing the acid-free hot-dip sheet material from molten steel of the invention adopts a process of directly changing from molten steel to hot-plated product by combining twin-roll strip casting technology and pickling-free hot-plating technology, mainly including: refining Molten steel, continuous casting strip, hot rolling, reduction annealing, hot-dip plating and other alloys, cooling coiling; compared with the traditional hot-dip product production process has the following advantages:
  • the process directly utilizes molten steel to produce hot-dip products, and integrates traditional slab, hot-rolling, pickling, cold-rolling, and de-hot-plating multiple production lines into one, which greatly shortens the processing flow, greatly improves production efficiency, and invests in equipment. Greatly reduced.
  • the reduction step uses two heating and insulation sections, first low temperature and high temperature, fully exerting the reduction characteristics at different temperatures, improving the reduction efficiency and effect.
  • the invention has many advantages such as simple process, low equipment investment, low energy consumption, high finished product rate and environmental protection.
  • FIG. 1 is a schematic diagram of a conventional one-stage reduction process route for direct production of acid-free hot-dip sheet metal strip by molten steel;
  • Fig. 2 is a scanning diagram of the cross-section effect of the reduction of the scale of the hot-rolled sheet on the surface of the hot-rolled sheet by the direct production of the acid-free hot-dip sheet metal strip by the molten steel (the reduction is not complete, the surface layer is reduced, and the bottom layer remains a large amount of oxide);
  • Fig. 3 is a scanning diagram of the effect of reducing the surface of the scale of the hot-rolled sheet on the surface of the hot-rolled sheet by the straight-line production of the acid-free hot-dip sheet material (there is a large crack on the surface, but the reduction efficiency is low, and a large amount of oxide is still present). );
  • Fig. 4 is a scanning diagram of the effect of reducing the cross-section of the surface of the hot-rolled sheet on the surface of the hot-rolled sheet by the direct-production of the acid-free hot-dip sheet metal strip by the molten steel (the reduction is not complete, the oxide is reduced, the center is still oxide);
  • Fig. 5 is a scanning diagram of the effect of reducing the surface of the scale of the hot-rolled sheet on the surface of the hot-rolled sheet by the direct production of the acid-free hot-dip sheet metal strip by the molten steel (the reduced iron is uniformly distributed on the surface, but the structure densely blocks the reduction gas transmission, affecting The reduction of the oxides to the inner layer eventually leads to incomplete reduction);
  • FIG. 6 is a schematic view showing a process route of a two-stage reduction method adopted in the reduction section process of the present invention.
  • Fig. 7 is a schematic view showing the process route of a method for directly producing a pickling-free hot-dip sheet material from molten steel according to an embodiment of the present invention.
  • Fig. 7 the reference numeral: ladle 1, tundish 2, twin roll caster 3, take-up tray 4, thin strip blank 5, support roll 6, pinch roll 7, hot rolling mill 8, reduction annealing furnace 9, The cooling section 11, the zinc pot heat preservation section 12, the zinc pot 13, the post-plating cooling section 14, and the coiler 15.
  • Figure 8 is a scanning diagram showing the effect of reducing the cross section of the scale on the surface of the segmented reduced hot rolled sheet according to one embodiment of the present invention.
  • Fig. 9 is a scanning view showing the surface reduction effect of the surface of the segmented reduced hot rolled sheet according to one embodiment of the present invention.
  • the invention relates to a method for directly producing a pickling-free hot-dip sheet material from molten steel, which can combine the strip casting production with the hot-plating production by the acid-free cleaning technology to realize the height of the steel from the liquid steel to the hot-plated product. Continuous production.
  • the method for directly producing a pickling-free hot-dip sheet material from molten steel of the present invention comprises the following steps:
  • the cast strip 5 is fed into the hot rolling mill 8 via the take-up tray 4, the support roll 6, and the pinch roll 7, and the cast strip is flattened to improve the shape of the strip; or rolled to Appropriate thickness changes the product specifications; when using large roughness rolls, it can also mechanically break the scale of the cast strip surface, which is beneficial to the subsequent reduction of the scale, the deformation rate is 1%-30%, better, The deformation rate is 5%, 10% or 20%.
  • the process is an optional process, and may also directly enter the reduction annealing stage without hot rolling;
  • Hot-dip plating in the case where the elemental iron is not mechanically brushed, it is directly cooled in the protective atmosphere by the cooling section 11, and then enters the short-term heat preservation section 12, and then enters the zinc pot 13, completes hot-dip galvanizing and other alloys. After the plating, the cooling section 14 is cooled and then taken up by the coiler 15.
  • the cooling of the cooling section 11 is as follows: cooling to 450-460 ° C when hot-dip galvanizing; cooling to 590-610 ° C when hot-dip aluminum zinc; cooling to 680-670 ° C when hot-plating aluminum silicon.
  • a single frame can be used, and in order to avoid oxidation of the surface of the steel plate, the air supply device can be added, and an inert gas can be introduced into the region intermittently or uninterrupted, thereby minimizing the chance of contact between the steel plate and the air, thereby reducing the oxidation of the surface of the steel plate. .
  • the inert gas is nitrogen or argon, and the reducing gas is hydrogen or carbon monoxide.
  • the mixed gas is turbulently flowed in the reduction annealing furnace 9, and the moisture content in the mixed gas is related to the hydrogen content and the temperature, and is different depending on the mixed gas requirement, and the hydrogen-water ratio (PH 2 /PH at 500 ° C) 2 O)
  • the minimum is 4.1
  • the hydrogen-to-water ratio (PH 2 /PH 2 O) is at least 0.9 at 1000 °C.
  • the hydrogen to water ratio (PH 2 /PH 2 O) is higher than 100 at 650 °C.
  • the average thickness of the scale of the strip surface should be controlled to 1-5 ⁇ m (the average thickness of the scale of the strip surface refers to the representative positions of the strip such as the head, the middle, the tail and the side, etc.
  • the position is taken at least three points, and the sum of the thicknesses of the scales measured at each point is divided by the total number of measurement points, and the result is the average thickness.
  • the hot-dip product retaining the reduced porous iron Performance does not have any effect.
  • the hot-plating step various operations such as alloying, oiling, embossing, coating or direct molding can be performed. Further, in the hot plating step, the plating layer may be pure Zn, Zn-Al, Zn-Al-Mg, Zn-Al-Mg-Si or Al-Si or other alloy.
  • the method for directly producing the acid-free hot-dip sheet metal strip from the molten steel of the present invention adopts the combination of the twin-roll strip casting technology and the pickling-free hot-plating technology to directly change the molten steel into the hot-plated product.
  • the process mainly includes: refined steel water, continuous casting thin strip blank, hot rolling, reduction annealing, hot-dip galvanizing and other alloys, cooling coiling; compared with the traditional hot-dip galvanizing product production process has the following advantages:
  • the process directly utilizes molten steel to produce hot-dip products, and integrates traditional slab casting, hot rolling, pickling, cold rolling, and de-hot galvanizing multiple production lines into one, which greatly shortens the processing flow and greatly improves the production efficiency. Investment has been greatly reduced.
  • Reduction section The principle of using this method to greatly increase the reduction rate is that at 450-600 °C, the iron trioxide in the oxide will be directly reduced to metallic iron, and the ferrous oxide will disproportionate at around 570 °C. , the formation of metal iron and ferroferric oxide, triiron tetroxide will be reduced to iron, these reaction rates are not very high, but will continue, in addition, the temperature is lower, the new reduction of iron is porous iron, will not The surface of the oxide is sintered to form a dense reduced iron layer, so that the smooth transfer of the reducing gas and the product is not blocked, and the reaction rate is mainly controlled by the intrinsic rate of the chemical reaction or the nucleation growth rate of the reduced iron.
  • the strip is heated to 700-1000 ° C.
  • the residual oxide will be completely reduced in a short time, and the loose porous structure of iron formed during the low-temperature reduction stage will not be in a short time.
  • the formation of dense reduced iron hinders the diffusion of reactants and products. With the prolonged holding time at high temperature, a certain sintering fusion occurs between the reduced iron and the reduced iron, and between the reduced iron and the steel substrate, which is also helpful for improving the adhesion of the reduced layer.
  • the process Compared with the existing reduction annealing process, the process has the following characteristics
  • the reduction efficiency is high.
  • the advantages of the reduction reaction in two temperature ranges are respectively utilized to realize high-efficiency reduction annealing, so that the iron oxide skin can be completely reduced in a short time.
  • the reduction at high temperature can make the reduction further thorough, and at the same time, the reduced iron produced has a sintering effect, so that the porous iron of the reduction product is not easily detached from the substrate, thus not polluting the furnace environment or causing the furnace roll Surface nodulation, etc.
  • the invention has many advantages such as simple process, low equipment investment, low energy consumption, high yield, high reduction efficiency and environmental protection.
  • the process route of this example is: casting belt solidification - hot rolling flattening - reduction annealing - cooling - hot dip galvanizing - cooling - finishing - crimping.
  • the refined molten steel is cooled and solidified by the casting belt machine 3 to obtain a thin strip blank 5, which enters the hot rolling unit 8 through the take-up tray 4, the support roller 6, and the pinch roller 7, and is subjected to heat flattening, and the deformation rate is 3%, and the reduction is performed.
  • Annealing furnace 9 because the iron oxide scale is thin at this time, and the temperature inside the furnace is high, the surface iron oxide scale is quickly completely reduced by elemental iron; directly after being cooled by the in-furnace cooling section 11 to the temperature of the zinc pot,
  • the hot section 12 is kept for a period of time, and is hot-plated into the zinc pot 13 and finally the strip is finally cooled by the plated cooling section 14 and is taken up after finishing.
  • This example is suitable for the production of ordinary low-carbon low-alloy steel hot-dip galvanizing, especially for the production of various steels represented by carbon structural steel.
  • the specific process parameters are shown in Table 1: The holding temperature before plating is determined according to the type of plating.
  • the cross-sectional morphology of the product after reduction is shown in Fig. 8.
  • the iron oxide scale is almost completely reduced, and there is no obvious residual oxide.
  • the reduced iron is loose and porous, and the reduction effect is obviously better than that of Fig. 2 and Fig. 4; the surface morphology is shown in Fig. 9.
  • the surface is porous and reduced iron, and there are large crack holes locally, which combines the characteristics of the single first stage low temperature section (Fig. 3) and the single second stage high temperature section (Fig. 5).
  • the process route of this example is: casting belt solidification - hot rolling - reduction annealing - cooling - insulation - hot galvanizing - cooling - finishing - crimping.
  • the refined molten steel is cooled and solidified by the casting machine 3 to obtain a thin strip blank 5, which enters the hot rolling unit 8 through the take-up tray 4, the support roller 6, and the pinch roller 7, and is hot rolled to a suitable thickness, and the deformation rate is 30%.
  • the blasting and air blowing equipment are added, and the inert gas nitrogen is continuously sent to the area, and then enters the reduction annealing furnace 9, and after cooling, the air is cooled by the cooling section 11 in the furnace to the temperature of the zinc pot,
  • the soaking section 12 is kept for a period of time, and is hot-plated into the zinc pot 13 and finally the strip is finally cooled by the plated cooling section 14 and is taken up after finishing.
  • This example is suitable for thinner gauge (less than 1mm) hot-dip galvanized sheet strip or thick strip of cast strip, which needs to be further thinned.
  • the reduction annealing process needs to be strengthened in this case, because thicker oxidation will occur during hot rolling. Iron sheet, thus adding inert gas protection measures.
  • Table 2 The specific process parameters are shown in Table 2:
  • the process route of this example is: casting belt solidification - reduction annealing - cooling - insulation - hot-dip galvanizing aluminum-magnesium - cooling - finishing - crimping.
  • the refined molten steel is cooled and solidified by the casting belt machine 3 to obtain a cast strip 5, which is directly introduced into the reduction annealing furnace 9 through the take-up tray 4, the support roller 6, and the pinch roller 7, and is cooled by the cooling section 11 in the furnace. After cooling to the temperature of the zinc pot, it is kept in the soaking section 12 for a period of time, and the zinc pot 13 is hot-galvanized with aluminum-magnesium. Finally, the strip is cooled by the plated cooling section 14 and finally coiled.
  • the reduction annealing process needs to be strengthened, and measures such as appropriately increasing the reduction temperature, prolonging the reduction time, and increasing the hydrogen concentration are provided.
  • the specific process parameters are shown in Table 3.
  • the process route of this example is: casting belt solidification - reduction annealing - cooling - insulation - hot-dip aluminum zinc - cooling - finishing - crimping.
  • the refined molten steel is cooled and solidified by the casting belt machine 3 to obtain a cast strip 5, which is directly introduced into the reduction annealing furnace 9 through the take-up tray 4, the support roller 6, and the pinch roller 7, and is cooled by the cooling section 11 in the furnace.
  • After cooling to the temperature of the zinc pot it is kept in the soaking section 12 for a period of time, and the zinc pot 13 is hot-plated with aluminum and zinc.
  • the strip is cooled by the plated cooling section 14 and is taken up after finishing.
  • the reduction annealing process needs to be strengthened, and measures such as appropriately increasing the reduction temperature, prolonging the reduction time, and increasing the hydrogen concentration are provided.
  • the specific process parameters are shown in Table 4:
  • the process route of this example is: casting belt solidification - reduction annealing - cooling - insulation - hot-dip aluminum silicon - cooling - finishing - crimping.
  • the refined molten steel is cooled and solidified by the casting belt machine 3 to obtain a cast strip 5, which is directly introduced into the reduction annealing furnace 9 through the take-up tray 4, the support roller 6, and the pinch roller 7, and is cooled by the cooling section 11 in the furnace.
  • After cooling to the temperature of the zinc pot it is kept in the soaking section 12 for a period of time, and the aluminum pot is hot-plated into the zinc pot 13 and finally the strip is finally cooled by the plated cooling section 14 and is taken up after finishing.
  • the reduction annealing process needs to be strengthened, and measures such as appropriately increasing the reduction temperature, prolonging the reduction time, and increasing the hydrogen concentration are provided.
  • the specific process parameters are shown in Table 5:
  • the above five embodiments can achieve the desired goals of the present invention, and the obtained hot-dip coating products can achieve the desired and customer demand.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Metallurgy (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Coating With Molten Metal (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Metal Rolling (AREA)
  • Continuous Casting (AREA)

Abstract

一种由钢水直接生产免酸洗热镀薄板带产品的生产方法,包括:获得精炼钢水;薄带连铸:在铸坯过程中用惰性气体与还原气体的混合气体保护;热轧;还原退火:在450-600℃以及700-1000℃两个范围内进行分段保温还原,以去除前工序中产生的氧化铁皮;热镀锌:在保护气氛下冷却后,进入锌锅进行热镀锌及其它合金,然后冷却卷取。

Description

由钢水直接生产免酸洗热镀薄板带产品的方法 技术领域
本发明涉及一种连续生产热镀产品的方法,尤其涉及一种由钢水直接生产免酸洗热镀薄板带产品的方法。
背景技术
随着资源与能源危机的不断加剧,环境保护、可持续发展、绿色经济、低碳经济等话题得到人们越来越多的重视,国家“十二五”规划也明确了将节能减排作为一项重要的任务来完成,这对于传统工业,尤其是钢铁行业提出了严峻的考验。
19世纪中叶,英国的Henry Bessemer首次提出用双辊连铸机浇注出金属薄带的方法,即一种将液态钢水直接浇铸成薄带坯的技术,从而省去了中间铸坯与热轧的环节。随着技术的不断进步,Bessemer的设想在最近的30年里得到了广泛的发展,世界各地的钢铁企业纷纷建立薄带连铸实验机组,其中一些还实现了产业化生产;这种由液态钢水直接浇铸成薄带坯的技术目前主要应用于不锈钢、高速钢以及有色金属的制造。在众多薄带连铸技术中,水平等径双辊式薄带连铸技术发展最为成熟,该方法可生产最终厚度为2-6mm的薄带坯。
与传统的板材生产工艺流程相比,薄带连铸技术具有流程短、基建投资少、实现“一火成材”等特点,大幅提高了钢材生产的能源效率,节约了生产成本。但薄带连铸产品表面质量不高,一般需要进行后续加工。
热镀锌包括热镀纯锌及其它合金的工艺是钢铁材料抗氧化、防止大气腐蚀的重要方法,热镀锌产品具有防护效果显著、表面质量好、成本低廉等特点,广泛应用于汽车、船舶、建筑等行业。目前市场上的热镀锌产品大部分是由连续热镀锌产线生产,这种工艺的生产周期较长,金属从液态钢水到进行连退热镀锌之间需经过铸坯、热轧、酸洗、冷轧等多工序,正是这些复杂的加工程序,导致薄带连铸与热镀锌工艺很难匹配,其中关键障碍即来自于酸洗工序,且酸洗工艺还会对环境造成严重的污染与破坏。
申请号为201310489332.6的中国专利公开了一种薄带连铸结合还原退火生产热轧免酸洗板的方法,其大致流程是将钢水铸轧成带坯、热平整后冷却卷取,为得到免酸洗产品,需将铸轧薄带卷重新开卷、还原退火,然后卷取成品或进行热镀锌,所得热镀锌产品仍是分线进行,工序较多,缺乏连续性。 US6588491B2的美国专利公开了一种直接生产免酸洗带钢的方法,其关键步骤是钢水浇铸成薄带、还原退火(氧化铁皮被还原成多孔铁)、机械法刷去多孔铁,得到免酸洗带钢,以此为核心,通过前后增加热轧、冷轧、涂油、热镀锌、电镀锌等工序,实现多种产品生产。其不足是还原产生的金属铁被机械刷除,既增加生产工序,又降低了金属收得率,增加生产成本;另外还原是在某个温度下保温还原、然后冷却,如图1所示,即采用的都是一段式保温还原程序,其所面临的主要难题都是氧化铁皮还原速度慢,效率低,还原不彻底,影响产品性能,见图2~图5,图2中的氧化铁皮还原不彻底,靠近表层被还原,底层残留大量氧化物;图3是热轧板还原后表面存在大的裂纹,但还原效率低,表面大量氧化物未来得及还原;图4中的氧化铁皮还原不彻底,氧化物颗粒周围被还原,中心仍是氧化物;图5中的还原铁在表面均匀分布,但结构致密反而阻挡还原气体传输,影响到里层的氧化物的还原,最终导致还原不彻底。
因此,迫切需要通过合理设计和优化出一种能够实现直接由钢水生产出免酸洗热镀锌薄板带产品的新方法,使得流程更短,还原效率更高,金属收得率更高。
发明内容
本发明的目的是提供一种由钢水直接生产免酸洗热镀薄板带产品的方法,可通过免酸洗技术将薄带连铸生产与热镀生产相结合,实现钢铁从液态钢水到热镀产品的高度连续化生产,并减少工序,提高了金属收得率。
为达到上述目的,本发明所提供的由钢水直接生产免酸洗热镀薄板带产品的方法,包括以下步骤:
熔炼、精炼,获得精炼钢水;
薄带连铸:精炼钢水经钢水包和中间包的调整,在密闭熔池内经双辊铸带机的冷却作用凝固成带坯,且在铸坯过程中用惰性气体与还原气体的混合气体进行保护;
还原退火:带坯入还原退火炉内,用还原气体与惰性气体的混合气体进行还原,以去除前工序中产生的氧化铁皮;
热镀:在保护气氛下冷却后,进入锌锅进行热镀锌或热镀其他合金,然后冷却卷取。
在薄带连铸之后还包括热轧步骤:在高温下对带坯进行平整改善板形、轧至合适厚度以改变产品规格,或对带坯表面氧化铁皮进行机械破碎,变形率在1%-30%。
所述的变形率为5%、10%或20%。
4.根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,在薄带连铸中,混合气体中的还原气体浓度为1%-10%。
在还原退火步骤中,还原过程包括两个加热保温段,如图2所示,分别对热轧板在450-600℃以及700-1000℃两个范围内进行分段加热保温,用以还原热轧板表面氧化铁皮,其中在450-600℃内还原1-5分钟,在700-1000℃范围内还原1-3分钟。在所述还原炉内从第一加热段开始直至冷却段出口一直保持有还原气体,其中各段的还原气体浓度为相同或不同,整个还原炉内还原气体的浓度为5%-100%。
所述的还原气体浓度为5-30%。
所述的还原气体浓度为5%、10%或15%。
所述惰性气体是氮气或氩气,所述还原气体是氢气或一氧化碳。
在热轧步骤中,采用单机架,并设置送风设备,用以间断或不间断向热轧区域通入惰性气体,以减少钢板与空气接触机会,从而降低钢板表面氧化。
在还原退火步骤中,所述的混合气体在炉内以湍流方式流通,混合气体中水分、氢气含量与温度有关,同一温度下,水分含量越少,即氢水比值越大,氧化铁还原效率越高,水分含量太高,即氢水比值低于一定值,还原将不能进行,不同温度下,该氢水比值最低值略有变化,温度高,氢水比值最低值略小。
在500℃时,氢水比最小为4.1;在1000℃时,氢水比最小为0.9。。
在进入还原退火炉之前,带坯表面的氧化铁皮的平均厚度控制为1-5μm。
在热镀步骤中,当热镀锌时需冷却至450-460℃;当热镀铝锌时需冷却至590-610℃;当热镀铝硅时需冷却至680-670℃。
在热镀步骤中,镀层为Zn、Zn-Al、Zn-Al-Mg、Zn-Al-Mg-Si、或Al-Si合金。
在热镀步骤后,可进行合金化、涂油、压花、涂膜或直接进行成型工序。
本发明的由钢水直接生产免酸洗热镀薄板带产品的方法是采用结合双辊薄带连铸技术与免酸洗热镀技术直接由钢水变成热镀产品的工艺,主要包括:精炼钢水、连铸薄带坯、热轧、还原退火、热镀及其它合金、冷却卷取;与同传统热镀产品生产流程相比具有以下优点:
1.产品生产流程短
该工艺直接利用钢水生产热镀产品,将传统的铸坯、热轧、酸洗、冷轧、连退热镀多条产线集成为一条,使得加工流程大幅缩短,生产效率大幅提升,设备投资大大降低。
2.经济、节能、环保
由于省去了大量中间加工、运输、存储及管理成本,且生产效率高,因此产品成本大大降低;不需要对热轧板进行表面除磷,也省去了原有的热轧后的冷却卷取再开卷、机械法刷去单质铁等步骤,金属收得率接近100%,并且获得产品的性能不变;省去中间环节的能耗,使得产品能耗大幅降低;生产过程中不使用任何污染性物质,也无有害废气、废液排放,环保优势突出;还原步骤采用两个加热保温段,先低温后高温,充分发挥不同温度下的还原特色,提升还原效率和效果。
因此,本发明具有工艺简单、设备投资低、能耗低、成材率高、环保等诸多优势。
附图说明
图1是传统由钢水直接生产免酸洗热镀薄板带产品一段式还原工艺路线示意图;
图2是传统由钢水直接生产免酸洗热镀薄板带产品一段式还原低温下热轧板表面氧化铁皮还原的截面效果扫描图(还原不彻底,靠近表层被还原,底层残留大量氧化物);
图3是传统由钢水直接生产免酸洗热镀薄板带产品一段式还原低温下热轧板表面氧化铁皮还原表面效果扫描图(表面存在大的裂纹,但还原效率低,且仍存在大量氧化物);
图4是传统由钢水直接生产免酸洗热镀薄板带产品一段式还原高温下热轧板表面氧化铁皮还原截面效果扫描图(还原不彻底,氧化物周围被还原,中心仍是氧化物);
图5是传统由钢水直接生产免酸洗热镀薄板带产品一段式还原高温下热轧板表面氧化铁皮还原表面效果的扫描图(还原铁在表面均匀分布,但结构致密阻挡还原气体传输,影响到里层的氧化物的还原,最终导致还原不彻底);
图6是本发明的还原段工艺采用的两段式还原方法的工艺路线示意图;
图7为本发明一个实施例的由钢水直接生产免酸洗热镀薄板带产品的方法的工艺路线示意图。
图7中标号:钢水包1、中间包2、双辊铸带机3、出带托板4、薄带坯5、支撑辊6、夹送辊7、热轧机8、还原退火炉9、冷却段11、入锌锅保温段12、锌锅13、镀后冷却段14、卷取机15。
图8是本发明一个实施例的分段式还原热轧板表面氧化铁皮还原截面效果扫描图;
图9是本发明一个实施例的分段式还原热轧板表面氧化铁皮还原表面效果扫描图。
具体实施方式
为让本发明的上述目的、特征和优点能更明显易懂,以下结合附图对本发明的具体实施方式作详细说明。首先需要说明的是,本发明并不限于下述具体实施方式,本领域的技术人员应该从下述实施方式所体现的精神来理解本发明,各技术术语可以基于本发明的精神实质来作最宽泛的理解。在附图中相同的附图标记表示相同的部分。
本发明是一种由钢水直接生产免酸洗热镀薄板带产品的方法,可通过免酸洗技术将薄带连铸生产与热镀生产相结合,实现钢铁从液态钢水到热镀产品的高度连续化生产。
如图7所示,本发明的由钢水直接生产免酸洗热镀薄板带产品的方法包括以下步骤:
(1)熔炼、精炼,获得精炼钢水;
(2)薄带连铸:液态钢水经钢水包1和中间包2的调整,在密闭熔池内经双辊铸带机3的冷却作用凝固成带坯,铸坯过程中用惰性气体与还原气体的混合气体保护,还原气体浓度是1%-10%;
(3)热轧:如图所示,铸轧带坯5经出带托板4、支撑辊6、夹送辊7进入热轧机8,对铸带坯进行平整改善板形;或轧至合适厚度改变产品规格;当采用大粗糙度轧辊时,还可对铸带坯表面氧化铁皮起到机械破碎作用,有利于后续氧化铁皮的还原,变形率在1%-30%,更佳的,所述的变形率为5%、10%或20%。该工序属于可选工序,也可不热轧直接进入还原退火阶段;
(4)还原退火:在还原退火炉9中,在450-600℃下用还原性气体与惰性气体的混合气体还原1-5分钟,在700-1000℃范围内还原1-3分钟,以去除前工序中产生的氧化铁皮,其中各段的还原气体浓度为相同或不同,整个还原炉内还原气体的浓度为5%-100%。较佳的,所述的还原气体浓度为5-30%。更佳的,所述的还原气体浓度为5%、10%或15%。
(5)热镀:在不进行机械法刷去单质铁的情况下,直接在保护气氛下经冷却段11冷却后,进入短暂保温段12,然后进入锌锅13、完成热镀锌及其它合金,经镀后冷却段14进行冷却后再经卷取机15进行卷取。上述冷却段11的冷却如下:当热镀锌时需冷却至450-460℃;当热镀铝锌时需冷却至590-610℃;当热镀铝硅时需冷却至680-670℃。
在热轧过程中,可采用单机架,并且为避免钢板表面发生氧化,可增加送风设备,间断或不间断向该区域通入惰性气体,尽量减少钢板与空气接触机会,从而降低钢板表面氧化。
而在还原退火步骤中,所述惰性气体是氮气或氩气,所述还原气体是氢气或一氧化碳。
并且,所述混合气体在还原退火炉9内采用湍流方式流通,混合气体中水分含量与氢气含量及温度有关,根据混合气体要求不同而不同,在500℃时,氢水比(PH2/PH2O)最小为4.1,在1000℃时,氢水比(PH2/PH2O)最小为0.9。较佳地,所述在650℃时,氢水比(PH2/PH2O)高于100。
在进入还原退火炉之前,带坯表面的氧化铁皮的平均厚度应控制在1-5μm(带坯表面氧化铁皮平均厚度指在带坯代表性位置如头部、中部、尾部和边部等,每个位置取至少三个点,并将各点所测氧化铁皮厚度的总和除以测量点的总个数,所得结果即为其平均厚度。如此,对保留有还原的多孔铁的热镀产品的性能不会产生任何影响。
在热镀步骤后,可进行合金化、涂油、压花、涂膜或直接成型等多种操作。另外,在热镀步骤中,镀层可以是纯Zn、Zn-Al、Zn-Al-Mg、Zn-Al-Mg-Si或Al-Si或其它合金。
由上述具体实施方式可知,本发明的由钢水直接生产免酸洗热镀薄板带产品的方法是采用结合双辊薄带连铸技术与免酸洗热镀技术直接由钢水变成热镀产品的工艺,主要包括:精炼钢水、连铸薄带坯、热轧、还原退火、热镀锌及其它合金、冷却卷取;与同传统热镀锌产品生产流程相比具有以下优点:
1.产品生产流程短
该工艺直接利用钢水生产热镀产品,将传统的铸坯、热轧、酸洗、冷轧、连退热镀锌多条产线集成为一条,使得加工流程大幅缩短,生产效率大幅提升,设备投资大大降低。
2.经济、节能、环保
由于省去了大量中间加工、运输、存储及管理成本,且生产效率高,因此产品成本大大降低;不需要对热轧板进行表面除磷,也省去了原有的热轧后的冷却卷取再开卷、机械法刷去单质铁等步骤,金属收得率接近100%,亦不会对产品的性能产生任何影响;省去中间环节的能耗,使得产品能耗大幅降低;生产过程中不使用任何污染性物质,也无有害废气、废液排放,环保优势突出.
3.还原段使用这种方法能够大幅提升还原速率的原理在于:在450-600℃条件下,氧化物中四氧化三铁会直接还原成金属铁,氧化亚铁在570℃左右会发生歧化反应,生成金属铁和四氧化三铁,四氧化三铁又会还原成铁,这些反应速率虽不是很高,但会持续进行,另外,温度较低,新还原产生的铁为多孔铁,不会在氧化物表面烧结形成致密的还原铁层,因此不会堵塞还原气体与产物的顺利传输,反应速率主要受限于化学反应的本征速率或受还原铁的形核长大速率控制。需要注意的是,由于温度较低,还原速率较慢,氧化物彻底被还原需要很长时间,因此,很多分散的氧化物仍残留在这些疏松多孔的结构中,也就是说,虽然表面被还原铁包裹,但内心仍存在大量分散的氧化物,需要长时间来还原。第二阶段,带钢被加热到700-1000℃,高温下,残留的氧化物会在很短的时间内被彻底还原,同时低温还原阶段形成的铁的疏松多孔结构,不会在短时间内形成致密的还原铁阻碍反应物与产物的扩散。随高温下保温时间延长,还原铁与还原铁之间,以及还原铁与钢基板之间会发生一定的烧结融合,这对提升还原层的附着力也是有帮助的。
同已有的还原退火工艺相比,该工艺具有以下特点
1还原效率高,通过两段式的保温退火,分别利用两个温度范围内还原反应的优点,实现了高效率的还原退火,使氧化铁皮在短时间内实现彻底还原。
2低温下还原不堵塞物质传输通道,高温下还原能使还原进一步彻底,同时对产生的还原铁有烧结作用,使还原产物多孔铁不易从基底脱落,因而不会污染炉内环境或造成炉辊表面结瘤等。
因此,本发明具有工艺简单、设备投资低、能耗低、成材率高、还原效率高、环保等诸多优势。
以下通过具体应用实施例进一步说明本发明的上述实施方式,以便更清楚理解本发明方法的特点、优点。
实施例1
本例实施工艺路线为:铸带凝固-热轧平整-还原退火-冷却-热镀锌-冷却-精整-卷曲。
精炼钢水经铸带机3冷却凝固后得到薄带坯5,经出带托板4、支撑辊6、夹送辊7进入热轧单元8,进行热平整,变形率3%,进入还原退火炉9,由于此时的氧化铁皮较薄,且炉内温度较高,表面氧化铁皮很快被完全还原单质铁;直接经过炉内冷却段11吹气冷却至入锌锅温度后,在均热段12保温一段时间,进锌锅13热镀,最后带钢被经镀后冷却段14终冷,精整后卷取。
本例适合普通低碳低合金钢热镀纯锌的生产,尤其适用于生产各种以碳素结构钢为代表的建筑用钢。具体的工艺参数示于表1:镀前的保温温度根据镀层种类而定。还原后产品截面形貌如图8所示,氧化铁皮基本彻底还原,无明显残留氧化物,还原铁呈疏松多孔状,还原效果明显优于图2和图4;表面形貌如图9所示,表面呈多孔状还原铁,且局部存在大的裂纹孔洞,综合了单独第一阶段低温段(图3)和单独第二阶段高温段(图5)的特征。
表1 碳素钢热镀锌的工艺参数
Figure PCTCN2014094611-appb-000001
实施例2
本例实施工艺路线为:铸带凝固-热轧-还原退火-冷却-保温-热镀锌-冷却-精整-卷曲。
精炼钢水经铸带机3冷却凝固后得到薄带坯5,经出带托板4、支撑辊6、夹送辊7进入热轧单元8,进行热轧至合适厚度,变形率30%,热轧工位区域内增加鼓风和抽风设备,不断向该区域送入惰性气体氮气,再进入还原退火炉9,还原后经炉内冷却段11吹气冷却至入锌锅温度后,在均热段12保温一段时间,进锌锅13热镀,最后带钢被经镀后冷却段14终冷,精整后卷取。
本例适合更薄规格(1mm以下)热镀锌板带坯或铸带坯较厚需要进一步减薄后使用的情况,本例还原退火工序需适当加强,因热轧过程中会产生较厚氧化铁皮,因此增加了惰性气体保护措施。具体的工艺参数示于表2:
表2 热镀锌产品的工艺参数
Figure PCTCN2014094611-appb-000002
实施例3
本例实施工艺路线为:铸带凝固‐还原退火‐冷却-保温‐热镀锌铝镁‐冷却‐精整‐卷曲。
精炼钢水经铸带机3冷却凝固后得到铸带坯5,经出带托板4、支撑辊6、夹送辊7直接进入还原退火炉9,还原后经炉内冷却段11吹气冷却至入锌锅温度后,在均热段12保温一段时间,进锌锅13热镀锌铝镁,最后带钢被经镀后冷却段14终冷,精整后卷取。
本例中还原退火工序需加强,通过适当提高还原温度,延长还原时间,提升氢气浓度等措施。具体的工艺参数示于表3,
表3 热镀锌铝镁产品的工艺参数
Figure PCTCN2014094611-appb-000003
实施例4
本例实施工艺路线为:铸带凝固‐还原退火‐冷却-保温‐热镀铝锌‐冷却‐精整‐卷曲。
精炼钢水经铸带机3冷却凝固后得到铸带坯5,经出带托板4、支撑辊6、夹送辊7直接进入还原退火炉9,还原后经炉内冷却段11吹气冷却至入锌锅温度后,在均热段12保温一段时间,进锌锅13热镀铝锌,最后带钢被经镀后冷却段14终冷,精整后卷取。
本例中还原退火工序需加强,通过适当提高还原温度,延长还原时间,提升氢气浓度等措施。具体的工艺参数示于表4:
表4 热镀铝锌产品的工艺参数
Figure PCTCN2014094611-appb-000004
Figure PCTCN2014094611-appb-000005
实施例5
本例实施工艺路线为:铸带凝固‐还原退火‐冷却-保温‐热镀铝硅‐冷却‐精整‐卷曲。
精炼钢水经铸带机3冷却凝固后得到铸带坯5,经出带托板4、支撑辊6、夹送辊7直接进入还原退火炉9,还原后经炉内冷却段11吹气冷却至入锌锅温度后,在均热段12保温一段时间,进锌锅13热镀铝硅,最后带钢被经镀后冷却段14终冷,精整后卷取。
本例中还原退火工序需加强,通过适当提高还原温度,延长还原时间,提升氢气浓度等措施。具体的工艺参数示于表5:
表5 热镀铝硅产品的工艺参数
Figure PCTCN2014094611-appb-000006
经实际验证,以上五个实施例均能实现本发明所期望目标,获得的热镀层产品均能达到产生期望及客户需求。
应理解,在阅读了本发明的上述讲授内容之后,本领域技术人员可以对本发明作各种改动或修改,这些等价形式同样落于本申请所附权利要求书所限定的范围。

Claims (15)

  1. 一种由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于,包括以下步骤:
    熔炼、精炼,获得精炼钢水;
    薄带连铸:精炼钢水经钢水包和中间包的调整,在密闭熔池内经双辊铸带机的冷却作用凝固成带坯,且在铸坯过程中用惰性气体与还原气体的混合气体进行保护;
    还原退火:带坯入还原退火炉内,用还原气体与惰性气体的混合气体进行还原,以去除前工序中产生的氧化铁皮;
    热镀:在保护气氛下冷却后,进入锌锅进行热镀锌或热镀其他合金,然后冷却卷取。
  2. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于,在薄带连铸之后还包括热轧步骤:在高温下对带坯进行平整改善板形、轧至合适厚度以改变产品规格,或对带坯表面氧化铁皮进行机械破碎,变形率在1%-30%。
  3. 根据权利要求2所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:所述的变形率为5%、10%或20%。
  4. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,在薄带连铸中,混合气体中的还原气体浓度为1%-10%。
  5. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:所述还原炉包括第一加热保温段和第二加热保温段,两个加热保温段分别对热轧板在450-600℃以及700-1000℃两个范围内进行分段加热保温,分别用以还原热轧板表面氧化铁皮,其中在450-600℃内还原1-5分钟,在700-1000℃范围内还原1-3分钟。在所述还原炉内从第一加热段开始直至冷却段出口一直保持有还原气体,其中各段的还原气体浓度为相同或不同,整个还原炉内还原气体的浓度为5%-100%。
  6. 根据权利要求5所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:所述的还原气体浓度为5-30%。
  7. 根据权利要求5或6所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:所述的还原气体浓度为5%、10%或15%。
  8. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:所述惰性气体是氮气或氩气,所述还原气体是氢气或一氧化碳。
  9. 根据权利要求2所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:在热轧步骤中,采用单机架,并设置送风设备,用以间断或不间断向热轧区域通入惰性气体,以减少钢板与空气接触机会,从而降低钢板表面氧化。
  10. 根据权利要求7所述的由钢水直接生产免酸洗热镀薄板带产品的生产方法,其特征在于:在还原退火步骤中,所述的混合气体在炉内以湍流方式流通,混合气体中水分、氢气含量与温度有关,同一温度下,水分含量越少,即氢水比值越大,氧化铁还原效率越高;水分含量太高,即氢水比值低于一定值,还原将不能进行,不同温度下,该氢水比值最低值略有变化,温度高,氢水比值最低值略小。
  11. 根据权利要求10所述的由钢水直接生产免酸洗热镀薄板带产品的方法,其特征在于:在500℃时,氢水比最小为4.1;在1000℃时,氢水比最小为0.9。
  12. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的方法,其特征在于:在进入还原退火炉之前,带坯表面的氧化铁皮的平均厚度控制为1-5μm。
  13. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的方法,其特征在于:在热镀步骤中,当热镀锌时需冷却至450-460℃;当热镀铝锌时需冷却至590-610℃;当热镀铝硅时需冷却至680-670℃。
  14. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的方法,其特征在于:在热镀步骤中,镀层为Zn、Zn-Al、Zn-Al-Mg、Zn-Al-Mg-Si、或Al-Si合金。
  15. 根据权利要求1所述的由钢水直接生产免酸洗热镀薄板带产品的方法,其特征在于:在热镀步骤后,可进行合金化、涂油、压花、涂膜或直接进行成型工序。
PCT/CN2014/094611 2014-05-30 2014-12-23 由钢水直接生产免酸洗热镀薄板带产品的方法 WO2015180462A1 (zh)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US15/314,934 US10683561B2 (en) 2014-05-30 2014-12-23 Method for directly producing pickling-free hot-plated sheet strip product from molten steel
DE112014006715.6T DE112014006715B4 (de) 2014-05-30 2014-12-23 Verfahren zum direkten Herstellen eines beizenfreien feuermetallisierten Dünnbandprodukts aus einer Stahlschmelze
RU2016152000A RU2701242C2 (ru) 2014-05-30 2014-12-23 Способ изготовления горячеплакированных изделий из тонкой стальной полосы непосредственно из расплавленной стали без травления
KR1020167034950A KR102413905B1 (ko) 2014-05-30 2014-12-23 쇳물로 직접 무산세 용융도금 박판 스트립 제품을 생산하는 방법
JP2017514761A JP6527942B2 (ja) 2014-05-30 2014-12-23 溶鋼から直接に製造された酸洗不要の溶融めっき薄板帯製品の製造方法

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
CN201410240632.5 2014-05-30
CN201410240643.3 2014-05-30
CN201410240643.3A CN105220101B (zh) 2014-05-30 2014-05-30 由钢水直接生产免酸洗热镀薄板带产品的方法
CN201410240632.5A CN105219929B (zh) 2014-05-30 2014-05-30 热轧板表面氧化铁皮的分段式还原方法

Publications (1)

Publication Number Publication Date
WO2015180462A1 true WO2015180462A1 (zh) 2015-12-03

Family

ID=54698025

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2014/094611 WO2015180462A1 (zh) 2014-05-30 2014-12-23 由钢水直接生产免酸洗热镀薄板带产品的方法

Country Status (6)

Country Link
US (1) US10683561B2 (zh)
JP (1) JP6527942B2 (zh)
KR (1) KR102413905B1 (zh)
DE (1) DE112014006715B4 (zh)
RU (1) RU2701242C2 (zh)
WO (1) WO2015180462A1 (zh)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109652639A (zh) * 2018-12-29 2019-04-19 佛山市诚德新材料有限公司 一种不锈钢带的退火炉
CN113996772A (zh) * 2021-11-04 2022-02-01 攀钢集团江油长城特殊钢有限公司 一种95Cr18的制备方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102018206343A1 (de) * 2018-04-25 2019-10-31 Volkswagen Aktiengesellschaft Verfahren und Anlage zur Serienfertigung warmumgeformter Blechformteile aus einem Stahlblechband
WO2020012222A1 (en) * 2018-07-11 2020-01-16 Arcelormittal Method to control the cooling of a metal product
WO2020012221A1 (en) * 2018-07-11 2020-01-16 Arcelormittal Method of heat transfer and associated device
WO2024056085A1 (zh) * 2022-09-15 2024-03-21 宝山钢铁股份有限公司 快速热处理带钢生产线

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06145937A (ja) * 1992-11-11 1994-05-27 Nisshin Steel Co Ltd 酸化スケ−ル付着熱延鋼板の溶融亜鉛めっき方法
JPH1088307A (ja) * 1996-09-13 1998-04-07 Nkk Corp めっき密着性に優れた溶融めっき鋼板の製造方法
US6622778B1 (en) * 2000-07-12 2003-09-23 Danieli Technology, Inc. Method for the direct production of scale-free thin metal strip
CN103537640A (zh) * 2013-10-18 2014-01-29 东北大学 一种薄带连铸结合还原退火生产热轧免酸洗板的方法
CN103726003A (zh) * 2013-12-20 2014-04-16 东北大学 一种基于氧化铁皮还原的热轧带钢免酸洗热镀锌方法

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05222571A (ja) * 1992-02-17 1993-08-31 Nippon Steel Corp アーク溶接性に優れた亜鉛めっき鋼板
US5904204A (en) * 1995-04-14 1999-05-18 Nippon Steel Corporation Apparatus for producing strip of stainless steel
JP3312103B2 (ja) * 1996-11-27 2002-08-05 川崎製鉄株式会社 高強度熱延鋼板
JP4136286B2 (ja) * 1999-08-09 2008-08-20 新日本製鐵株式会社 耐食性に優れたZn−Al−Mg−Si合金めっき鋼材およびその製造方法
US10071416B2 (en) 2005-10-20 2018-09-11 Nucor Corporation High strength thin cast strip product and method for making the same
US7451804B2 (en) * 2006-11-22 2008-11-18 Peterson Oren V Method and apparatus for horizontal continuous metal casting in a sealed table caster
AU2008247367B2 (en) * 2007-05-06 2013-05-16 Nucor Corporation A thin cast strip product with microalloy additions, and method for making the same

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06145937A (ja) * 1992-11-11 1994-05-27 Nisshin Steel Co Ltd 酸化スケ−ル付着熱延鋼板の溶融亜鉛めっき方法
JPH1088307A (ja) * 1996-09-13 1998-04-07 Nkk Corp めっき密着性に優れた溶融めっき鋼板の製造方法
US6622778B1 (en) * 2000-07-12 2003-09-23 Danieli Technology, Inc. Method for the direct production of scale-free thin metal strip
CN103537640A (zh) * 2013-10-18 2014-01-29 东北大学 一种薄带连铸结合还原退火生产热轧免酸洗板的方法
CN103726003A (zh) * 2013-12-20 2014-04-16 东北大学 一种基于氧化铁皮还原的热轧带钢免酸洗热镀锌方法

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109652639A (zh) * 2018-12-29 2019-04-19 佛山市诚德新材料有限公司 一种不锈钢带的退火炉
CN109652639B (zh) * 2018-12-29 2024-02-09 佛山市诚德新材料有限公司 一种不锈钢带的退火炉
CN113996772A (zh) * 2021-11-04 2022-02-01 攀钢集团江油长城特殊钢有限公司 一种95Cr18的制备方法
CN113996772B (zh) * 2021-11-04 2023-06-16 攀钢集团江油长城特殊钢有限公司 一种95Cr18的制备方法

Also Published As

Publication number Publication date
KR102413905B1 (ko) 2022-07-05
US20170114427A1 (en) 2017-04-27
JP6527942B2 (ja) 2019-06-12
RU2701242C2 (ru) 2019-09-25
RU2016152000A3 (zh) 2018-10-22
KR20170015927A (ko) 2017-02-10
DE112014006715T9 (de) 2017-04-20
DE112014006715T5 (de) 2017-02-16
US10683561B2 (en) 2020-06-16
RU2016152000A (ru) 2018-07-02
DE112014006715B4 (de) 2023-08-24
JP2017516921A (ja) 2017-06-22

Similar Documents

Publication Publication Date Title
WO2015180462A1 (zh) 由钢水直接生产免酸洗热镀薄板带产品的方法
CN103726003B (zh) 一种基于氧化铁皮还原的热轧带钢免酸洗热镀锌方法
WO2015180500A1 (zh) 热轧免酸洗直接冷轧还原退火热镀产品的生产方法
WO2020169076A1 (zh) 一种降低双辊连铸产线轧机轧制力的方法
CN104046892A (zh) 一种用于显像管防爆带的冷轧热镀铝锌钢板及其生产方法
CN103537640B (zh) 一种薄带连铸结合还原退火生产热轧免酸洗板的方法
CN105220101B (zh) 由钢水直接生产免酸洗热镀薄板带产品的方法
WO2021052426A1 (zh) 一种薄规格高耐蚀钢及其生产方法
CN112222189A (zh) 一种高表面质量高强if冷轧钢带的生产方法
CN112522566A (zh) 一种薄规格花纹钢板/带及其制造方法
EP4353860A1 (en) Pre-coated steel plate for hot forming and preparation method therefor, and hot-formed steel member and application thereof
CN105219929B (zh) 热轧板表面氧化铁皮的分段式还原方法
WO2021052319A1 (zh) 高强薄规格高耐蚀钢及其制造方法
CN112522575A (zh) 一种薄带连铸生产薄规格花纹钢板/带的方法
TW202229565A (zh) 一種鍍鋁鋼板、熱成形部件及製造方法
CN112522591B (zh) 一种薄带连铸生产高强高耐蚀钢的方法
CN113981324A (zh) 一种用于热成形的3.0mm以下薄规格抗高温氧化热轧酸洗钢板及其生产制造方法
CN102814628B (zh) 一种建筑装潢装饰用低镍奥氏体不锈钢和铜冷复合卷材的生产方法
JP2965970B1 (ja) 鋼板の連続処理ラインおよび連続処理方法
CN112126854A (zh) 一种镀锡板冷轧基板的生产方法
CN108754381A (zh) 一种钢带镀铝锌铬的连续生产方法
WO2021052317A1 (zh) 一种耐硫酸露点腐蚀用热轧钢板/带及其制造方法
CN115365317A (zh) 一种免涂镀、抗氧化的2000MPa热成型钢制备方法
CN114589201A (zh) 一种电镀锡用冷轧极薄钢带的生产方法
JPS63235485A (ja) 溶融めつき鋼板の製造方法

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: 14893277

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2017514761

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 15314934

Country of ref document: US

WWE Wipo information: entry into national phase

Ref document number: 112014006715

Country of ref document: DE

ENP Entry into the national phase

Ref document number: 20167034950

Country of ref document: KR

Kind code of ref document: A

ENP Entry into the national phase

Ref document number: 2016152000

Country of ref document: RU

Kind code of ref document: A

122 Ep: pct application non-entry in european phase

Ref document number: 14893277

Country of ref document: EP

Kind code of ref document: A1