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    • 专利摘要:
    The invention relates to a method for producing a microalloyed tubular steel in a cast-rolled composite plant (1) and the microalloyed tubular steel, which can be produced by the application of the method according to the invention. The object of the invention is to propose a method for the cost-effective production of a microalloyed tubular steel, with which the microalloyed tubular steel can be produced inexpensively, reliably and with high quality. This object is achieved by the method according to claim 1.
    公开号:AT512399A4
    申请号:T989/2012
    申请日:2012-09-10
    公开日:2013-08-15
    发明作者:Bernd Dipl Ing Dr Linzer；Axel Dipl Ing Rimnac
    申请人:Siemens Vai Metals Tech Gmbh；
    IPC主号:
    专利说明:

    10th Sep 2012 13:39 Siemens CIC P 201221105
    No. 4647 p. 5/37
    »· 10 15 20 25 30
    Description: TECHNICAL FIELD The invention relates to a method for producing a microalloyed tubular steel in a cast-rolled composite rod and the microalloyed tubular steel obtained by the use of the invented ballasted steel rod and microalloyed tubular steel Method can be produced. The term microalloyed refers to steels to which 0.01 to 0.1% by mass of niobium, vanadium or titanium are alloyed (or higher contents of a combination of said elements), for example by high strength due to the formation of carbides and nitrides and grain refining to achieve. The alloy particles partially dissolve upon heating to forming temperature. They are dissolved in austenite and cause an increase in the recrystallization temperature. In the transformation of the deformed Austenitkornes into ferrite and perlite, bainite or martensite is formed depending on the degree of transformation refined transformation structure. In addition, they form carbides when cooled with carbon and nitrides with nitrogen. The grain refining thus produced increases the strength, substantially without reducing the toughness. The yield strength is a material characteristic value and refers to the stress up to which a material exhibits no visible plastic deformation with uniaxial and torque-free tensile stress. When the yield strength is exceeded, the material no longer returns to its original shape after relieving, but a sample extension remains. The yield strength is usually determined by tensile testing and expressed in units of N / mm2 = MPa. 10/09/2012 13:42
    No .: R564 P. 005/037 lO.Sep. 2012 13:39 201221105
    Siemens CIC P
    Kr. 4647 8. 6/37
    • ·
    Steel grades with a minimum yield strength of at least 485 N / mm2 are required for the API 5L-X7Q, API 5L-X80 of the American Petroleum Institute (API for short) or higher. Thus, according to the standard API 5L-X70, steel has a yield strength 5 of at least 48b N / mm: and a tensile strength of at least 570 N / mm 2.
    This standard refers to steel products that can be used by welding to make tubes for the pipeline construction, and therefore must have a certain strength, but at the same time have a high ductility at low temperatures. The production of such steel products requires certain procedures. 15 State of the art
    In the case of previous production processes for such steels, the following prerequisites must generally be met: 20 The steel composition can only be made of pure iron with low sulfur and phosphorus contents, the addition of micro-alloying elements, such as niobium Nb, titanium Ti, vanadium V, to obtain a fine grain is necessary. 25 In the production of the slab must be by suitable
    Temperature control can be prevented, that segregations, ie demixing of the melt occur. They arise during the transition of the melt in the solid state and give different material properties within the slab. Furthermore, it can be prevented with a suitable temperature control that form cracks in the second ductility minimum.
    The rolling of the slab is carried out by so-called 35 thermomechanical rolling:
    During pre-rolling, a uniformly heated slab from a heating furnace with a relatively coarse-grained 10/09/2012 13:42
    No .: R564 P, 006/037 10. Sep. 2012 13:40 Siemens C1C P 201221105
    No. 4647 p. 7/37
    10 15 20 25 30
    Microstructure in the roughing mill (Rcugbing Mill), it must in order to achieve the recrystallization, in which the relatively coarse-grained structure of the slab increasingly fine-grained, the thickness of the steel urr, at least 40% can be reduced, usually in reversing mode. Fine austenite grain is necessary before the rolling stock is further deformed in the finishing train. During finish rolling in the finishing train, the final deformation takes place in a temperature range at which the material no longer recrystallises - typically in the temperature range of 800-900 ° C. In order to achieve the desired material properties, the steel strip is stretched by at least a factor of 2.5, usually higher than 3. Typical inlet temperatures of the steel strip in the finishing train are between 800 and 900 ° C. The exit temperature of the steel strip exiting the finishing train is typically in the range of 830 ° C. An accelerated cooling of the steel strip after exiting the finishing train leads to the formation of particularly fine ferrite grains, possibly even to the formation of acicular (acicular) ferrite. This achieves a very fine-grained conversion structure with high strength and very good toughness. EP 1 978 121 A1 discloses a corresponding process for producing easily weldable steel sheets having a yield stress of at least 350 MPa and a tensile strength of at least 570 MPa, in which the steel in the finishing train is thermomechanically rolled. From the publication C. Klein et al. From CSP to CSP flex - the new concept for thin-slab technology, steel and iron 131 (2011), No. 11. 10/09/2012 13:43
    No .: R564 P.007 / 037 10. Sep. 2012 13:40 Siemens CIO P 201221105
    No. 4647 p. 8/37
    io 15 20 25 30 it is known to use the tube steer API X70 on a "CSP flex". Gi ed-VJa 1 z-Verbundanl age produce. A disadvantage of the proposed Herstellungsverfähren is that the molten steel must have a relatively high alloying Ali1, in particular of niobium, in order to limit the grain growth of the cut thin slab strand in a heating furnace (usually a tunnel furnace). Due to the high alloy content, the production costs per ton of finished strip increase. A disadvantage of the previous method is that it comes through the long residence of the steel in the heating furnace before the roughing mill and / or the finishing train to undesirable grain growth. This is to be prevented by the present invention. Summary of the Invention The object of the invention is to overcome the disadvantages of the prior art and to propose a method of inexpensively producing a microalloyed tubular steel with which the microalloyed tubular steel can be inexpensively, i. with low operating costs for the molten steel and low energy costs for the production, - reliable, i. that the tube steel can be produced even with unavoidable fluctuations in the manufacturing process with approximately constant quality, and - can be produced with high quality. This object is achieved by the method according to claim 1. Advantageous embodiments are the subject of the dependent claims. Another object is to provide a high quality tubular steel grade X70 steel which, compared to the prior art, has a low share of 10/09/2012 13:43
    No .: R564 P.008 / 037
    10th Sep 2012 13:41 Siemens CIC P 201221105
    No. 4647 p. 9/37 ·· * · ··· * ft ··· ft ·· «* * · * ··· # ··· · ♦ ♦ * · · · · · · · · · · ·
    Has alloying elements, but with comparably good mechanical properties.
    This object is achieved by the microalloyed tubular steel according to claim 5. 10 15 20
    Concretely, the former object is achieved by a method for producing a micro-alloyed tubular steel in a cast-roll composite plant, wherein the cast-rolling composite plant is a continuous casting machine with a mold and a strand guide, a single- or multi-stand roughing mill, an induction furnace, a descaling comprising a multi-stand finishing train, a cooling section and a storage device, comprising the following method steps: pouring a molten steel in the mold into a partially solidified thin slab strand, wherein the molten steel in weight percent of 0.04-0.05% C, 1.3-1, 5% Mn, 0.035-0.05%
    Nb, 0.035-0.061 V, 0.2-0.4% Cr, 0.2-0.3% Si, 0.015-0.05% Al, < 0.008% N, the remainder being Fe and unavoidable impurities, 25 30 35 - diverting the partially solidified thin slab strand into an arcuate strand guide; - supporting, guiding and cooling the thin slab strand in the arcuate strand guide; - Redirecting the thin slab strand in a horizontal strand guide, wherein the thin slab strand solidifies in either the arcuate or the horizontal strand guide; Pre-rolling the uncut thin slab strand into a pre-strip in the roughing train, the thin slab strand entering the roughing train having a core temperature which is at least 50 ° C, preferably at least 100 ° C higher than its surface temperature, and the thin slab strand in the roughing train with a total reduction of at least 40%, preferably at least 50%, is pre-rolled, and takes place during roughing a complete static recrystallization of the structure; |
    I 10/09/2012 13:44
    No .: R564 P.009 / 037 10. Sep. 2012 13:41 Siemens C1C P 201221105 N o. 4647 p. 10/32 »· · ··· **« »» ··· 't ft I · «· · · * · * ·» · »** | * * * · »• * * · · · ·, 15e. Reheating the pre-strip in the induction furnace to an average pre-strip temperature of > 1000 ° C; Descaling the reheated pre-strip in the descaling device; 5 - finish-rolling the descaled pre-strip in a first group of rolling mills of the finishing train to a partially finished pre-strip, wherein the structure of the pre-strip after a rolling pass in the first group of rolling mills of the finishing train at least partially, 10 preferably completely, statically recrystallized; immediately thereafter - finish rolling the partially finished pre-strip in a second group of rolling mills of the finishing train to a finished strip, the structure 15 of the partially finished pre-strip not recrystallized; - cooling the finished strip in the cooling section; - Cutting and storing the finished strip in the storage device. 20
    Under "dynamic recrystallization" the recrystallization of the deformed structure is still referred to in the nip. The dynamic recrystallization is completed when the material leaves the nip. Furthermore, in contrast to static recrystallization, the 25 dynamic recrystallization is stimulated by high forming speeds. In contrast, "static recrystallization" is understood to mean the recrystallization of the deformed structure outside the nip. The static recrystallization is primarily excited by high degrees of deformation.
    By means of the process according to the invention, it is possible to cast a substantially lower-alloyed molten steel (in the case of the CSP flex 35 production process 0.06% Nb, but good results can also be obtained with 0.035% Nb in the process according to the invention) in the continuous casting machine due to the lower alloy shares 10/09/2012 13:45
    No .: R564 P.010 / 037 10. Sep. 2012 13:42 Siemens CIC P 201221105
    No. 4647 p. 11/37
    15 20 25 30 reduces the manufacturing costs and the weldability of the tubular steel can be improved. Typically, the thin slab strand emerges from the mold in the vertical direction (in the case of a straight mold) or essentially in the vertical direction (in the case of a curved mold) and is subsequently bent into an arc-shaped strand guide in order to maximize casting heat from the continuous casting process into the pre-casting or continuous casting In the roughing process, it is advantageous for the thin slab strand in the strand guide to solidify only briefly (typically a few meters) prior to rough rolling in the roughing train Temperature profile (ie that the core temperature of the thin slab strand is at least 50 ° C higher than the surface temperature) of the thin slab strand allows all cross sections of the thin slab strand in the roughing almost uniformly reduced and uniformly r This ensures that the core region of the pre-strip also has a fine-grained structure. The complete static recrystallization completely transforms the coarse-grained cast structure into a fine-grained rolling structure. Since the pre-strip still has a lot of casting heat from the continuous casting process, it is i.A. sufficient to reheat the pre-strip with low energy input. For this purpose, an induction furnace is used according to the invention. The induction furnace allows to react rapidly to changing conditions (e.g., changed casting speeds due to ladle change in the continuous casting machine) and yet to keep the run-in temperature in the finish rolling mill or final rolling temperature constant at the final pass in the finishing line. Furthermore, the induction furnace, at relatively low frequency 10709/2012 13:45 No .: R564 P.011 / 037 lÖ.Sep. 2012 13:42 201221105
    Siemens CIC P
    Mr. 4647 p. 12/37 • I · * ·· »··« * * · a · • · «a * aat · .6 *. the energization of the inductors to heat the cross section of the pre-strip much more uniform than is the case with a tunnel oven. In addition, the rapid rewarming in the induction furnace keeps the grain growth 5 low and reduces or largely prevents embrittlement at the austenite grain boundaries.
    After reheating, the pre-strip is descaled. This can of course be omitted if the induction furnace is operated in an inert or reducing atmosphere.
    The finish rolling of the pre-strip in the finishing train takes place in two steps. In a first group of rolling mills of the finishing train, the preliminary strip is at least partially recrystallized by static recrystallization to form a partially finished pre-strip. As a result, a particularly fine-grained microstructure is formed. Immediately thereafter, the partially finished pre-strip is not recrystallized in a second group of rolling mills of the finishing train. thermomechanical, finish-rolled to finished strip thickness.
    After finish rolling, the finished strip is rapidly cooled to storage temperature (i.e., coiling temperature at a reel 25 or storage temperature at discharge of plates) such that the finished strip has particularly fine-grained ferrite and bainite grains.
    Then the cooled finished strip is cut to 30 coil weight or plate length and in one
    Storage device, e.g. at least one reel device for so-called. Coils or a storage device for plates stored. According to the invention, a reduction of the achievable strengths of the finish strip, as in conventional process control due to the low proportions of alloying elements (in particular niobium and / or 10/09/2012 13:46
    No .: R564 P.012 / 037 10. Sep. 2012 13:43 201221105
    Siemens CIC P Φ * .5 * · * fr «·« «« «« * • · · ♦ tlt · »· | • * * * * · · · No. 4647 p. 13/37
    Titanium) would inevitably occur in the molten steel, compensated by a precipitation hardening (English, precipitation hardening) of the finishing strip. The precipitation hardening is promoted on the one hand by a steeper temperature gradient in the case of 5 finish rolling, on the other hand the precipitations have less time to grow, so that overall a finer microstructure ensues. The finer texture maximizes contribution to strength enhancement due to cutting and circumventing so that precipitation strengthening is maximized due to precipitation hardening.
    By the production process according to the invention, the particle sizes D of the precipitates (eg niobium carbides, niobium nitrides, vanadium carbides, optionally also titanium nitrides) in the finished strip are typically 2 nm i D 12 nm. It is advantageous if all method steps from casting of the molten steel up to and including the finish rolling of the steel melt partially finished rolled Vorstreifens, possibly also the cooling of the finished strip, carried out in continuous operation. 25
    It is advantageous if the semi-solidified thin slab strand in the arcuate strand guide and / or the horizontal strand guide of the continuous casting machine is subjected to LCR (Liquid Core Reduction, i.e. thinner reduction of the non-solidified thin slab strand). The LCR typically reduces the thickness of the thin slab strand between 1 and 30 mm (measured between the exit of the mold and the through-solidification point).
    The production of a salable ready-made strip will be facilitated or the number of rolling stands in the roughing mill and finishing mill will be kept low if the 10/09/2012 13:46
    No .: R564 P.013 / 037 35 I'O. Seρ. 2012 13:43 201221105
    Siemens C1C F
    Ir. 4647 p. 14/37 * * · «10 ► · 4 " The continuous slab strand leaves the continuous casting machine with a thickness of 80-160 mm, preferably 90-125 mm, more preferably 95-115 mm. The specified requirements for a sellable finished strip in particular meets a 5 finished strip with a thickness of 4-26 mn.
    In general, it is expedient if the thin slab strand in the roughing mill is pre-rolled by one to three rolling passes. 10
    Furthermore, it is advantageous if each rolling pass during rough rolling has a reduction ratio of 12-60%, wherein in particular the first pass a reduction of 30-60%, the second pass a reduction of 20-60%, and the third pass a reduction from 12-40% takes place.
    In order to prevent embrittlement of the austenitic grain or to prevent the grain from growing too strongly, it is advantageous if one or more reheating phases of a maximum of 120 s, preferably <1 to 2 mm, are carried out between the roughing train and the finished mill. 90 s, more preferably &lt; 75 s, total duration take place.
    The temperature drop by the descaling is kept low when the descaling by a
    Hochdruckentzunderer, in particular a high-pressure Rotationsentzunderer occurs. For the formation of a fine grain during finish rolling, it is advantageous if the partial, preferably the complete, static recrystallization of the partially finish-rolled preliminary strip takes place after the first or the second rolling pass in the first group of rolling mills of the finishing train. For a good surface quality or good geometry of the finish strip, it is advantageous if the partially finished pre-strip in the second group of 10/09/2012 13:47
    No .: R564 P.014 / 037 35 11ID. September 2012 1 3:44 Siemens CIC P 201221105
    No. 4647 p. 15/37 * ·· «(·
    Rolling mills of the finishing train is not recrystallized finishing, with typically a total reduction of 2: 50% takes place. At the last rolling pass in the finishing train, the lowest reduction of all b rolling stands on the finishing train should happen. For achieving or maintaining an accurate finish rolling temperature, it is advantageous if an actual temperature of the partially finished rolled finished strand 10 is detected immediately before the last stand of the finishing train by means of a temperature measuring device and fed to a controller, and that the controller taking into account a target temperature determines a manipulated variable and at least one inductor of the induction furnace 15 so controlled that the actual temperature of the target temperature corresponds as possible. Usually, target temperature, i. the finish rolling temperature, set between 780 and 850 ° C. For maximum strength of the finish strip, it is advantageous if the surface of the finish strip in the cooling section is cooled at a cooling rate of -10 ° K / s. In order to further increase the strength of the finish strip by the formation of titanium nitrides or titanium carbides, it is sufficient if the molten steel &lt; 1000 ppm Ti. Specifically, the second object is achieved by providing the microalloyed tube steel obtainable by the method according to any one of claims 1 to 13, a chemical composition in weight percent of 0.04-0.05% C, 1.3-1, 5% Mn, 0.035-0.05% Nb, 0.035-0.06% V, 0.2-0.4% Cr, 0.2-0.3% Si, 35 &gt; 0.0151 Al, &lt; 0.008% N, the rest Fe and inevitable
    Contaminants, wherein at least 75% of the precipitates of the tubular steel at room temperature have a size of 2nm ^ D ^ 12nm, and the tubular steel the 10/09/2012 13:47
    No .: R564 P.015 / 037
    2012 13:44 Siemens CIC P
    No. 4647 p. 16/37
    2C1221105 mechanical requirements for steel grade X70 according to the standard API 5A / IS03183: 2007. Typically, the grain size of the tubular steel is between 4 and 8 μιη. 5 Brief description of the drawings
    Further advantages and features of the present invention will become apparent from the following description of non-limiting embodiments, reference being made to the following 10 figures, which show:
    1 shows a schematic representation of a 15 20 according to the invention
    Cast-rolled composite plant for the continuous production of micro-alloyed tubular steel in side view
    FIG. 2 shows a detailed representation of a strand guide of the installation from FIG. 1 in a vertical sectional view;
    Increasing the strength of the invention
    Method by precipitation hardening
    4 shows a representation of the microstructure of the finished strip 3 '' with a final thickness of 6 mm at room temperature. FIG. 5 shows a variant of the cast-rolling composite system from FIG. 1 for illustrating the final rolling temperature control 25
    Description of the embodiments
    FIG. 1 shows schematically a cast-rolled composite installation 1 on which the method according to the invention for continuous rolling of steel hot-rolled strip can be carried out.
    It can be seen a continuous casting machine with a mold 2, are cast in the strands 3. To the mold 2 includes a strand guide 6. Then the rough rolling takes place in a 10/09/2012 13:48
    No .: R564 P.016 / 037
    10, Sep. 2012 13:45 Siemens CIC P
    No. 4647 p. 17/37 201221105 13 * • &lt;
    Pre-rolling line 4, which here consists of three rolling stands 4lr 42, 42 and in which the strand 3 is rolled into a pre-strip 3 '. During roughing, the transformation of cast structure into fine-grained rolling structure takes place. The 5 transport direction of the pre-strip 3 'is shown by arrow 15.
    The cast-rolling composite apparatus 1 further comprises a number of components, e.g. a descaling device 42 and 10 in Fig. 1, not shown separating means, which in
    Substantially correspond to the state of the art and which is therefore not discussed here at this point. The e.g. In any case, severing devices designed in the form of cutters are arranged after the finishing train 5 and serve to separate the finished rolled steel strips
    Plates or coils from the following band. The scissors can cut through thicknesses of up to 26 mm at belt speeds of 0.3 to 5 m / s, either by moving the entire pair of scissors or at least one pair of drums in synchronism with the belt speed
    Continuous casting rolling process between the thickness d and the width b of the steel strip and the belt speed v as a function of the width-specific throughput the relationship applies: 25 v * b - 0.350 ... 0.600 m2 / min or v * b = 0.006 ... 0.012 m2 / s.
    Of course, further separation devices can be arranged at further positions of the cast-rolling composite installation 1, for example, upstream of the rough rolling mill 4, or between the rough rolling mill 4 and the finishing train 5, 30.
    After the roughing train 4 is an induction furnace 7 for the
    Preliminary strip 3 'arranged. Preferably, a
    Cross field heating induction furnace using the casting 10/09/2012 13:48
    No .: R564 P, 017/037 lO.Sep. 2012 13:45 201221105
    S i eireπs CIO P
    No. 4647 p. 18/37 14 M ··· ··· »·« &lt; * * »· 2 * ·« «*» * ·:: * * ♦ &lt; * * * · ♦ * ·
    Roll compound system 1 makes it particularly energy efficient. In the induction furnace 7, the pre-strip 3 'is brought into the finishing train 5 relatively uniformly over the cross-section to a desired inlet temperature for the inlet. 5
    After heating in the induction furnace 7 takes place - after an interposed optional descaling in the descaling 42 - the finish rolling in the five-stand finishing train 5 by means of the 10 finishing mills 5i, 52, 53, 54, $ 5 to a desired
    Immediately before the underfloor reel 19 of 15 finished strip 3 '' between pinch rollers 20 is clamped, the finished strip 3 '' also lead and keep under tension. For continuous casting, the so-called LCR process (liquid-core reduction process) can be used, in which the 20 extruded from the mold 2 strand 3 is reduced by means of the subsequent strand guide 6 at liquid cross-sectional core of the strand 3.
    For the LCR thickness reduction of the strand 3, predetermined guide elements 9, 10 (typically strand guide rollers) of the strand guide 6 are (transversely) adjustable relative to a longitudinal axis of the strand 3, with an adjustment of the guide elements depending on the material of the strand and / or or the casting speed is made to reduce the strand thickness by up to 30 mm.
    According to FIG. 2, the strand guide 6 comprises several (usually three to fifteen) strand guide segments 16, 10/09/2012 13:49
    No .: R564 P.018 / 037 * 4 ·· · * ·· 15 iö. September 201 2 13:46 Siemens CIC P 201221105
    No. 4647 p. 19/37 wherein each segment 16 comprises one or more (usually three to ten) pairs of guide elements 9, 10, preferably designed as strand support rollers. The support rollers are rotatable about an orthogonal to the transport direction of the strand 3 5 extending axis. Instead of strand support rollers, it would also be conceivable to use individual guide elements as static, z.R. run skid-shaped components. Regardless of the specific embodiment of the guide elements 9, 10, these are arranged on both sides of the strand broad sides, so that 10 of the strand is guided by upper and lower guide element series.
    As can be seen in FIG. 2, the guide segments 16 are each constituted by a lower series of guide elements 9 and 15 of a parallel or converging upper series of guide elements 10. Each guide element 9 of the lower guide element series is assigned to an opposite guide element 10 of the upper guide element series. 20
    Between the two guide elements series 9, 10 a for receiving a emerging from the mold 2 strand 3 receiving shaft 11 is formed, which by forming different distances opposite 25 guide elements 9, 10 to each other in the transport direction of the
    Stranges 3 is at least partially tapered and thereby the strand 3 is thickness reducible.
    The upper and lower Führungselemente- or support rollers 9, 30 10 each in turn (sub-) series specific
    Support rollers with different diameters and / or center distances to be structured. 10/09/2012 13:49
    No .: R564 P.019 / 037 16
    ··· · II 16 ·· · · II Ir. 4647 p. 20/37
    ίο. September 20 1 2 1 3:46 Siemens CIC P 201221105
    The upper guide elements 10 are selectively depth-adjustable or may be approximated to the lower guide elements 9, e.g. by means of a hydraulic drive. One of the desired strand thickness d at the end 14 of the strand guide 6 corresponding and measured between opposing upper and lower guide elements clear receiving width 12 of the receiving shaft 11 of the strand guide 6 could e.g. be reduced from 125 mm to a range between 95 and 115 mm. 10
    Since a guided in a narrower receiving shaft 11 strand 3 solidifies and cools faster, the casting speed and equivalent to the rolling trains 4, 5 continuous flow would have to be increased if you want to continue to approach the bottom 15 of the strand as close as possible to the end of the strand guide 6 ,
    To reduce the thickness of the strand 3, e.g. three to eight guide elements (pairs) 9, 10 of one of the mold 2 20 facing - but not necessarily adjoining the mold 2 - first guide segment 16 'adjustable Alternatively, a plurality of juxtaposed guide segments 16 are used for LCR thickness reduction, directly or connect indirectly to the mold 2 25.
    The strand thickness d or the light receiving width 12 can be set as a function of the material of the strand 3 and / or as a function of the casting speed. The adjustment of the respective guide elements 9, 10 takes place in a direction substantially orthogonal to the transport direction of the strand, wherein both the upper guide elements 10 and the lower guide elements 9 can be adjustable. The upper guide elements 10 are 10/09/2012 13:50
    No .: R564 P.020 / 037 17 17 No. 4647 p. 21/37
    10th Sep 2012 13:47 Siemens CIC P * * * 1 »· · ►» · 4 ·· * «201221105 hinged to corresponding support elements 17, which are preferably hydraulically adjustable.
    The (hydraulically) adjustable LCR guide elements 9, 10 5 are preferably arranged in one of the mold 2 facing the front half, preferably in one of the mold 2 facing the front quarter of the longitudinal extension of the strand guide 6. 10 The use of the LCR method leads to particularly low
    Segregation rates, since both finer solidification microstructure can be achieved and macrosegregations are suppressed by the more intensive mixing of the melt associated with the LCR process. 15
    Between the end 14 of the strand guide 6 and an inlet region of the rough rolling 4 only one caused by the relative to the strand surface very low ambient temperature conditional cooling of the strand 3 20 is allowed, i. there is no artificial cooling of the
    Stranges 3 by means of a cooling device. The surface of the strand 3 has in this area on average a temperature &gt; 1050 ° C, preferably &gt; 1000 ° C. However, between the end 14 of the strand guide 6 and the first roughing stand 4i, a hinged thermal cover could also be provided in order to keep the heat in the strand 3 as much as possible. The thermal cover surrounds a conveying device provided for transporting the strand 3, usually designed as a roller belt, at least in sections. Here, the thermal cover may surround the conveyor from above and / or from below and / or laterally.
    As the end 14 of the strand guide 6 is here provided for strand contacting guide surface or 10/09/2012 13:50
    No.: R564 P.021 / 037 18 10. Sep. 2012 13:47 201221105
    S i emens C! C P
    Ir. 4647 p. 22/37
    Mantle line of the last of the pre-rolling 4 facing guide element or the last support roller 10a of the upper guide elements 10 understood. According to the invention, the following method steps are carried out in the cast-rolling composite installation 1:
    First of all, a molten steel consisting of% by weight of 0.04% C, 1.3% Mn, 0.035% Nb, 005% V, 0.2% Cr, 0.2% Si, 0.03% 10 Al, &lt; 0.008% N, the balance Fe and unavoidable impurities, cast in a mold 2 of the continuous casting a teilerstarrter thin slab strand 3 with a thickness of 100 mm immediately after the mold 2. Subsequently, the strand 3 is reduced in the liquid-core-15 reduction (LCR'-) process by means of the strand guide 6 with a liquid cross-sectional core to a strand thickness d of 85 mm. Following the LCR, the solidification of the strand 3 takes place shortly before the end of the arcuate strand guide 6. 20
    The subsequent rough rolling, reheating and finish rolling is shown below with reference to the stitch plan of Table 1. In this example, a steel melt having the chemical composition shown in Fig. 25 of the last paragraph is used as the starting material. From this, a strand with a thickness of 85 mm and a width of 1900 mm is cast at a casting speed of 5.0 m / min.
    In the first example, a strip with the final thickness of 30 6 mm and the final width of 1900 mm is rolled from it.
    In Table 1, in the first column, in each case the individual rolling stands or the other facilities of the roughing and finishing train are entered, where "H" is a &quot; Admission 10/09/2012 13:51
    No .: R564 P.022 / 037 lO.Sep. 2012 13:48 2012211C5
    S e m e s s C1C P • · »··· * · * · * * · · ** * * · ·
    No. 4642 p. 23/31 19 into the induction furnace 7 (its beginning), "H from &quot; the exit of the pre-strip 3 'from the induction furnace 7 (the end thereof) and "ignition &quot; the descaler 42. 5 The following columns show: - the thickness of the steel strip in mm, measured after the passage of the respective rolling stand, - the reduction (thickness decrease) of the steel strip in the corresponding rolling stand relative to the thickness of the preceding rolling stand, and the temperature of the steel strip in ° C at the respective rolling mill or when entering and leaving the induction furnace. 7 15 table 1:
    Framework Thickness Red. Temp. [Mm] [%] [° C] 4i 42.5 50 1108 42 21.25 50 1062 4s 19 11 1026 H on 19 905 H off 19 1050 Fltr. 19 1043 5i 10.45 45 960 52 7,315 30 910 53 6, 58 10 870 5 &lt; 6, 06 5 835 5s 6 1 805
    The strand 3 thus emerges in the first example with a thickness d of 85 mm and a temperature in the range of 1130-1300 ° C from the strand guide 6 and enters the first mill stand 20i of the roughing mill 4th When entering the roughing mill 4 10th / 09/2012 13:51
    No .: R564 P.023 / 037 Lö.Sep. 2012 13:48 201221105
    Si emens CIC P · «« • ♦ Φ 4 • · · «► * ··· · * ·« • · · y · ** «·«
    No. 4647 24/37 20 ** 10 15 the thin slab strand 3 has a core temperature which is at least 50 cC higher than the surface temperature of the uncut strand. In the first stand 4i of the rough rolling mill 4, the strand 3 is reduced by 50% to a thickness of 42.5 mm, whereby it cools to 1108 ° C. In the second rolling stand 42, another pass is made with a reduction of 50% to 21.3 mm thickness. When leaving the second stand 42, the strand 3 has only a temperature of 1062 ° C. A third trick is no longer taking place in the Vorwalzstraße 4. When passing through the third roll stand 43 without reduction and until it enters the induction furnace 7, the present pre-strip 3 'cools to 905 ° C. without forced cooling, only because of the radiation of the pre-strip 3'. This cooling could be reduced by covers.
    In the induction furnace 7, the pre-strip 3 'is reheated so that it emerges from the induction furnace 7 at a temperature of 1050 ° C. By descaling in the descaling device 42, the pre-strip 3 'cools down to 1043 ° C. and enters the first rolling stand 5i of the finishing train 5 at approximately this temperature. There is a reduction in five passes, so using all rolling stands 5χ to 55 of the finishing train 5 according to the values 25 in Table 1. The finished strip 3 '' occurs with a
    Final temperature of 805 ° C from the finishing train 5 off.
    After the first rolling pass in the rolling stand 5i or the second rolling pass in the rolling stand 52 of the finishing train 5, a partial static recrystallization of the structure takes place. The recrystallization stop temperature of the steel used is 900 ° C. In the last three rolling passes S3.5 ", 55 in the finishing train 5 there is no recrystallization of the 10/09/2012 13:52
    No .: R564 P.024 / 037 ίο. Sed. 2012 13:49 201221105
    Siemens CIC P
    No. 4647 p. 25/37 21 * »ft ·
    Structure instead, i. it is ausschiießlich the so-called thermomechanical rolling.
    In the present embodiment, the end band 3 "is further cooled to a reeling temperature between 500 ° C. and 750 ° C., preferably 550 ° C. to 650 ° C., and wound up into a bundle. The cooling of the finished strip in the cooling section 18 is carried out at a cooling rate of 15 K / sf so that the finely dispersed present precipitates in 10 finished strips in the structure "locked". whereby the increase in strength of the finish strip due to precipitation hardening is maximized. Finally, a transection of the finished strip 3 '' in a direction transverse to the transport direction 15 direction and a 15 Fertigauchaspeln the rolling mill side loose ready strip 3 ''. As an alternative to coiling, a deflection and stacking of the finished strip 3 "would also be possible.
    The heating of the pre-strip 3 'takes place within a period of 20 to 50 seconds. The finish rolling stands 5j-5¾ are each spaced at intervals of &lt; 7 m, preferably at intervals of &lt; 5 m arranged to each other (measured between the working rolling axes of the finishing mills bn-hs). The working roll diameter of the rough rolling stands in the plant according to Fig 1 670-750 mm.
    The resulting tubular steel of 6 mm thickness has a measured particle diameter of 5.2 pm at room temperature. The tensile strength is 594 N / mm2. 30
    FIG. 3 shows schematically the contribution of the production method according to the invention for increasing the strength of the finished strip 3 "by the precipitation hardening. According to the sizes of the precipitates (here 10/09/2012 13:52
    No .: R564 P.025 / 037 10. Sep. 2012 13:49 Siemens CIC P 201221105
    No. 4647 p. 26/37, especially niobium carbides, niobium nitrides and vanadium carbides) between 2 and 12 nm, compared to 15 to 30 nm in a prior art production process. Due to the size of the precipitates, the strength enhancing contributions due to cutting and bypassing precipitation hardening are maximized so that the lower alloyed tubular steel also achieves comparable strength characteristics to a higher alloy tubular steel produced in a conventional manufacturing process 10.
    FIG. 4 shows a representation of the microstructure of tubular steel with a thickness of 6 mm in an electron backscatter diffraction (EBSD) microscope. The research institute CSM (Centro 15 Sviluppo Material!) Italy has confirmed that the tubular steel produced according to the invention meets the requirements for steel grade X70 of the standard API bL / ISO 3183: 2007. FIG. 5 shows a variant of the cast-rolling composite installation from FIG. 1 for illustrating the final rolling temperature control according to claim 10. Either shortly before the partially finished pre-strip 3 'passes through the last stand 55 of the finishing train, or shortly after the finished strip 3' ' 25 last frame 5s has passed through the finishing train 5, the actual temperature TlEt of the front strip 3 'and the finished strip 3' 'by a temperature measuring device, not shown (eg, a pyrometer) is measured. By an analog or digital controller 30 of the control error e between a target temperature TSon (specifically, the target final rolling temperature) and the actual temperature Tist is determined, the controller 30 outputs a manipulated variable u and at least one inductor 7 'of the induction furnace (in the concrete case, the last two transverse field inductors 7 ') so 10/09/2012 13:53
    No .: R564 P.026 / 037 1 &amp; Sep, 2 0 1 2 1 3:50 Siemens CIC P 201221105 &gt; * * · «· * · ·«
    Ir. 4647 p. 27/37 controls that the actual temperature Tlsc corresponds as closely as possible to the Sol1 temperature Tsoii. As a result, the actual temperature of the belt is kept at high end-of-roll temperature even with variations in the manufacturing process (for example, a reduction in casting speed at the time of a ladle change).
    Reference List of Drawings 1 Coated Rolling Compound 2 Chill 3 "Finished Strip 4 Pre-Rolling Line 4i First Pre-rolling Stand 42 Second Pre-Rolling Stand 43 Third Pre-Rolling Stand 5 Finish Rolling Line 5i First Finish Rolling Stand 52 Second Finish Rolling Stand 53 Third Finish Rolling Stand 54 Fourth Finish Rolling Stand 5s 5th Finish Rolling Stand 6 Strand guide 7 induction furnace 1 'inductor 9 lower guide elements 10 upper guide elements 10a last support roller of the upper guide elements 10 11 receiving shaft 12 light receiving cross section of the strand guide 6 14 end of the strand guide 6 10/09/2012 13:53
    No .: R564 P.027 / 037 24 24 &gt; · · »!« ··· 10-Sep. 20 1 2 1 3:50 Siemens C! C P 201221105. ... V-4647 p. 23/37 15 Transport direction 16 Guide segment 16 'First guide segment 17 Support elements 18 Cooling section 19 Underfloor reel 20 Driving rollers 30 Regulator 42 Descaling device d Strang tec tis Actual temperature Tsoii So11 temperature u Actuating variable 10/09/2012 13:53
    No .: R564 P.028 / 037
    权利要求:
    Claims (14)
    [1]
    ] 0th September 2012 13:51 Siemens CIC P

    No. 4647 p. 29/37

    Claims 1. A method for producing a microalloyed tubular steel in a cast-roll composite plant (1), wherein the cast-rolled composite plant (1) comprises a continuous casting machine having a mold (2) and a strand guide (6), a on or multistage preheating line (4), an induction furnace (7), a descaling device (42), a multi-stand finishing train (5), a cooling section (18) and a storage device (19), comprising the following method steps: casting a molten steel in the mold (2) to a semi-solidified thin slab strand (3), the molten steel by weight being 0.04-0.05% C, 1.3-1.5% 15 Mn, 0.035-0.05% Nb, 0.035-0, 06% V, 0.2-0.4% Cr, 0.2-0.3% Si, 0.015-0.05% Al, &lt; 0.0081 N, the remainder being Fe and unavoidable impurities; - Diverting the partially solidified thin slab strand (3) in an arcuate strand guide (6);
    20 - supporting, guiding and cooling the thin slab strand (3) in the arcuate strand guide (6); - Diverting the thin slab strand (3) in a horizontal strand guide (6), wherein the thin slab strand (3) solidifies in either the arcuate or the horizontal strand guide (6); - Vorwalzen the uncut thin slab strand (3) to a pre-strip (3 ') in the roughing mill (4), wherein the thin slab strand (3) on entering the Vorwalzstraße (4) has a core temperature which is at least 50 ° C, 30 preferably at least 100 ° C, is higher than its surface temperature, and the thin slab strand (3) in the roughing train (4) with a total reduction of at least 40%, preferably at least 50%, is pre-rolled, and during roughing a complete static recrystallization 35 of the structure of takes place; Reheating the pre-strip (3 ') in the induction furnace (7) to an average pre-strip temperature of &gt; 1000 ° C; 10/09/2012 13:54 No .: R564 P. 029/037 1G. September 2012 13:51 Siemens CIC P 201221105 26 *



    No. 4647 p. 30/37 - descaling the reheated pre-strip (3 ') in the descaling device (42); Finish rolling the descaled leader (3 ') in a first group (£> i, S2) of rolling mills of the 5 finishing train (5) into a partially finished pre-strip (3'), the structure of the leader (3 ') following a Rolling pass in the first group (5i, 52) of rolling mills of the finishing train (5) at least partially, preferably completely, statically recrystallized; immediately thereafter - finish rolling of the partially finished pre-strip (3f) in a second group (53, 54, 55) of rolling mills of the finishing train (5) to a finished strip (3 ''), wherein the structure of the partially finish-rolled strip 15 (3 ') non-recrystallized, cooling the finished strip (3 '') in the cooling section (18), cutting and storing the finished strip (3 '') in the storage device (19)
    [2]
    2. The method according to claim 1, characterized in that the partially solidified thin slab strand (3) in the arcuate strand guide (6) and / or the horizontal strand guide (6) of the continuous casting machine is subjected to an LCR. 25
    [3]
    3. The method according to claim 2, characterized in that the solidified thin slab strand (3) the continuous casting machine with a thickness (d) of 80-160 mm, preferably 90-125 mm, more preferably 95-115 mm leaves. 30
    [4]
    4. The method according to any one of the preceding claims, characterized in that the thin slab strand (3) in the rough rolling mill (4) by one to three rolling passes (4if4a, 43) is pre-rolled.
    [5]
    5. The method according to claim 4, characterized in that each rolling pass (4i, 42, 43) has a reduction ratio of 12-60%, wherein in particular at the first rolling pass (4j) a 10/09/2012 13:54 No .: R564 P.030 / 037 TO. September 2012 13:52 201221105 Siemens CIC P • · No. 4647 p. 31/37 ···· ·· * «** ·« «« *. ··· ··· * 27 reduction of 30-60%, the second pass (42) a reduction of 20-60%, and the third pass (4b) a reduction of 12-40%.
    [6]
    6. The method according to any one of the preceding claims, characterized in that between the roughing train (4) and the finishing train (5) one or more reheating phases of a maximum of 120 s, preferably &lt; 90 s, more preferably &lt; 75 s, total duration take place. 10
    [7]
    7. The method according to any one of the preceding claims, characterized in that the descaling by a Hochdruckentzunderer (42), in particular a Rotationsentzunderer takes place. 15
    [8]
    8. The method according to any one of the preceding claims, characterized in that the partial, preferably the complete, static recrystallization of the partially finished pre-strip (3 ') after the first or the second 20 pass in the first group of rolling stands (5i, 52) of Fertigwalzstraße (5) takes place.
    [9]
    9. The method according to any one of the preceding claims, characterized in that the partially finished rolled pre-strip 25 (3 ') in the second group of rolling stands (53,54,55) of the finishing train (5) is not finished recrystallizing finished, wherein in the second group from rolling mills (53f54.5s,) typically has a total reduction of &gt; 50% takes place.
    [10]
    10. The method according to any one of the preceding claims, characterized in that an actual temperature (TIST) of the partially finished pre-strip (3 ') immediately before the last frame (5s) of the finishing train (5) detected by a temperature measuring device and a controller (30 ) Is supplied 35, and that the controller (30), taking into account a desired temperature (TSoii) determines a manipulated variable (u) and at least one inductor (7 ') of the induction furnace (7) is controlled so that the actual 10 / 09/2012 13:55 no .: R564 P.031 / 037 ext. September 20 12 13:52 Siemens CIC P

    No. 4647 p. 32/37 ** ·· * · ·· * »&tt;

    Temperature (TisC) of the Sol2 temperature (Ts0n) corresponds as possible.
    [11]
    11. The method according to any one of the preceding claims, 5 characterized in that the surface of the finished strip (3 '' ') in the cooling section (18) is cooled at a cooling rate of ^ 10 ° K / s.
    [12]
    12. The method according to any one of the preceding claims, 10 characterized in that the finished strip (3 '') has a thickness of 4-26 mm.
    [13]
    13. The method according to any one of the preceding claims, characterized in that the molten steel &lt; 1000 ppm Ti 15 has.
    [14]
    A microalloyed tubular steel obtainable by the process of any one of the preceding claims, having a chemical composition in weight percent of 0.04-0.05¾

    0.2-0.3% Si, &gt; 0.015% Al, &lt; 0.008% N, the remainder being Fe and unavoidable impurities, characterized in that at least 75% of the precipitates of the tubular steel at room temperature have a size 2nm ä D &lt; 12nm, and the 25 tubular steel meets the mechanical requirements for steel grade X70 according to API 5L / IS03183: 2007 standard. 10/09/2012 13:55 No .: R564 P.032 / 037
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    同族专利:
    公开号 | 公开日
    ITMI20131444A1|2014-03-11|
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    US20140072824A1|2014-03-13|
    US9144839B2|2015-09-29|
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    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    DE10047044A1|2000-09-22|2002-04-25|Sms Demag Ag|Processes and plants for the production of steel strips and sheets|
    US20060243420A1|2002-07-06|2006-11-02|Gunter Flemming|Method and continuous casting and rolling plant for semi-endless or endless rolling by casting a metal strand, especially a steel strand, which is cut to length as required after solidification|
    EP1918405A1|2006-10-30|2008-05-07|ThyssenKrupp Steel AG|Process for manufacturing steel flat products from silicon alloyed multi phase steel|
    EP1918406A1|2006-10-30|2008-05-07|ThyssenKrupp Steel AG|Process for manufacturing steel flat products from boron microalloyed multi phase steel|
    EP1918403A1|2006-10-30|2008-05-07|ThyssenKrupp Steel AG|Process for manufacturing steel flat products from a steel forming martensitic structure|
    DE102009037278A1|2009-08-12|2011-02-17|Sms Siemag Ag|Apparatus and method for producing a thin hot strip|
    EP2441538A1|2010-10-12|2012-04-18|Siemens VAI Metals Technologies GmbH|Strand casting device with dynamic strand thickness reduction|
    DE19529046A1|1995-07-31|1997-02-06|Mannesmann Ag|Method and device for operating a continuous caster|
    IT1302582B1|1998-10-01|2000-09-29|Giovanni Arvedi|PROCESS AND RELATED PRODUCTION LINE FOR THE DIRECT MANUFACTURE OF FINISHED PIECES PRINTED OR DRAWN FROM ULTRA-THIN HOT TAPE|
    DE102008020412A1|2007-08-24|2009-02-26|Sms Demag Ag|Method and device for producing a metal strip by casting rolls|
    CA2731908C|2008-07-31|2013-09-24|Jfe Steel Corporation|Thick-walled high-strength hot rolled steel sheet with excellent low-temperature toughness and method for producing same|
    EP2163659B1|2008-09-11|2016-06-08|Outokumpu Nirosta GmbH|Stainless steel, cold strip made of same and method for producing cold strip from same|
    CN102612569B|2009-11-18|2015-03-11|新日铁住金株式会社|High strength hot-rolled steel plate exhibiting excellent acid pickling property, chemical conversion processability, fatigue property, stretch flangeability, and resistance to surface deterioration during molding, and having isotropic strength and ductility|
    CN103160746A|2011-12-14|2013-06-19|鞍钢股份有限公司|High strength steel for thick wall water pipe and manufacturing method thereof|WO2015188278A1|2014-06-13|2015-12-17|M3 Steel Tech Inc.|Modular micro mill and method of manufacturing a steel long product|
    AT519277A1|2016-11-03|2018-05-15|Primetals Technologies Austria GmbH|Casting and rolling plant|
    IT201700028732A1|2017-03-15|2018-09-15|Danieli Off Mecc|COMBINED PLANT OF CONTINUOUS CASTING AND LAMINATION OF HOT METALLIC TAPES|
    CN107130178A|2017-04-27|2017-09-05|甘肃酒钢集团宏兴钢铁股份有限公司|A kind of high-strength wheel steel of 500Mpa grades of automobile and its CSP technique productions methods|
    CN107130179A|2017-04-27|2017-09-05|甘肃酒钢集团宏兴钢铁股份有限公司|Low manganese micro titanium alloy Q345B hot rolled strips and the production method based on CSP flows|
    CN108796373B|2018-06-25|2020-04-07|武汉钢铁有限公司|Steel for generator excitation element produced by CSP process and manufacturing method thereof|
    CN111944974A|2020-07-23|2020-11-17|武汉钢铁有限公司|Method for producing thin-specification strip steel with good surface quality based on CSPprocess|
    CN113199577A|2021-05-06|2021-08-03|博海威玛（烟台）机械有限公司|Plate bending device|
    法律状态:
    2016-06-15| PC| Change of the owner|Owner name: PRIMETALS TECHNOLOGIES AUSTRIA GMBH, AT Effective date: 20160415 |
    2018-05-15| MM01| Lapse because of not paying annual fees|Effective date: 20170910 |
    优先权:
    申请号 | 申请日 | 专利标题
    ATA989/2012A|AT512399B1|2012-09-10|2012-09-10|Method for producing a microalloyed tubular steel in a cast-rolled composite plant and microalloyed tubular steel|ATA989/2012A| AT512399B1|2012-09-10|2012-09-10|Method for producing a microalloyed tubular steel in a cast-rolled composite plant and microalloyed tubular steel|
    IT001444A| ITMI20131444A1|2012-09-10|2013-09-04|PROCEDURE FOR PRODUCING A MICROLEGATED STEEL FOR TUBES IN A COMPOSITE PLANT OF CASTING AND LAMINATION AND STEEL MICROLEGATED FOR TUBES|
    US14/023,021| US9144839B2|2012-09-10|2013-09-10|Method for producing microalloyed tubular steel in combined casting-rolling installation and microalloyed tubular steel|
    CN201310408797.4A| CN103667648B|2012-09-10|2013-09-10|Method and the microalloy tube blank steel of microalloy tube blank steel is manufactured in rolling casting bonding equipment|
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