KR20130100215A - Method for producing a hot-rolled flat steel product - Google Patents

Abstract

The present invention relates to a method for producing sheet steel products from economical and reliable working methods from steels containing high Al content as well as high Mn content. The process according to the invention, together with Fe and unavoidable impurities, (in weight%) C: 0.5% to 1.3%, Mn: 18% to 26%, A1: 5.9% to 11.5%, Si: <1%, Cr : <8%, Ni: <3%, Mo: <2%, N: <0.1%, B: <0.1%, Cu: <5%, Nb: <1%, Ti: <1%, V: < Dissolving the molten steel S containing 1%, Ca: <0.05%, Zr: <0.1%, P: <0.04%, S: <0.04%, casting the molten steel into a casting strip; Heating the casting strip at a heating rate of at least 20 K / s to an initial hot rolling temperature of 1100 ° C. to 1300 ° C., hot rolling the casting strip heated to an initial hot rolling temperature into a hot strip, and Cooling to <400 ° C. at a cooling rate of at least 100 K / s within 10 seconds after hot rolling, and winding the cooled hot strip into a coil at a winding temperature of up to 400 ° C.

Description

METHOOD FOR PRODUCING A HOT-ROLLED FLAT STEEL PRODUCT}

The present invention relates to a method for producing hot rolled sheet steel products from high strength super ductile manganese steels having a high Mn content as well as an Al content of 5.9% to 11.5% by weight.

Steels of this type and methods for their production are known, for example, from DE-AS 1 262 613. According to the method described in that publication, after a small diameter block is cast from molten steel having a suitable composition, it is hot rolled to form a bar stock. By heat treatment at 800 ° C to 1250 ° C, the elongation and notch impact strength of the material obtained in this way can be improved. From the stock obtained in this way, components such as aircraft, flooring, turbines, gears, valves and the like are manufactured.

According to a more recent development, the above-described type of steel is suitable for sheet products and therefore steel strips and by means of a very good combination of properties of high strength, high deformability, significantly reduced specific gravity and minimized associated weight. It is found to be suitable for steel seats, in particular for the production of components for motor vehicle production, in particular for the production of vehicle bodies and undercarriage members.

However, in this case, there is a problem that the steel is difficult to treat due to the alloying state produced by a conventional method commonly applied to steels having a high carbon content. In such known steels, core segregation of Mn and Al tends to occur during casting and solidification. Moreover, this increases the risk of surface cracking during continuous casting and during strand bending back upon separation from the casting mold. Moreover, due to the low thermal conductivity, a long preheating time is generally required to raise the slab cast from the steel to the temperature required for hot rolling. The long furnace holding time of the slabs is associated with a marked tendency of surface decarburization. At the same time, low thermal conductivity causes the problem of crack formation due to recrystallisation inertia of the low temperature strip edge during preheating, bloom and hot rolling. Finally, the steel exhibits extremely high resistance to hot and cold during hot and cold rolling, which is considerably higher than high-alloy steels such as, for example, RSH steel or conventional high-alloy Mn steel.

From US Pat. No. 7,794,552 B2, with iron and unavoidable impurities, from 0.85% to 1.05% C, 16% to 19% Mn, up to 2% Si, up to 0.050% Al, up to 0.030% S , Up to 0.050% P, up to 0.1% N, Cr content up to 1%, Mo content up to 1.5%, Ni content up to 1%, Cu content up to 5%, Ti content up to Optionally containing one or more elements selected from "Cr, Mo, Ni, Cu, Ti, Nb, V" under conditions of 0.50%, Nb content up to 0.50%, and V content up to 0.50% It is known to produce plate steel products from hot rolled steels of austenitic high manganese content of conventional construction. Here, the recrystallized surface fraction of the steel strip or sheet is equal to 100%, and the recrystallized surface fraction of the precipitated carbide is equal to 0%. At the same time, the average grain size of the steel is 10 μm or less. The strength of known steel produced in this way exceeds 1200 MPa and the product of strength at break and elongation exceeds 65000 MPa.

In order to achieve this, according to the known method, correspondingly constructed steel molten metal is cast to form a semi-finished product which may be slabs, thin slabs or cast strips. The semi-finished product is heated to a temperature of 1100 ° C. to 1300 ° C. and rolled into a hot rolled sheet at a rolling end temperature of at least 900 ° C. Then, if necessary, time is maintained to achieve the desired complete recrystallization of the strip surface. The resulting hot rolled strip is then cooled to a maximum winding temperature of 400 ° C. and wound into a coil at a cooling rate of at least 20 ° C./s. The hot strip obtained in this way can then be rolled into a cold strip, which is subjected to intermediate annealing if necessary.

The method known from the above publication US 7,794,552 B2 is directed to steels in which the Al content is limited to a maximum of 0.05% by weight, although Al can be used for deoxidation during smelting, in order to avoid precipitation of AlN. The presence of AlN precipitates thus leads to the risk of crack formation during processing of steel strips produced in a known manner.

Against the background of the above-mentioned prior art, it is an object of the present invention to disclose an economical and reliable working method for producing plate steel products from steels containing not only high Mn content but also high Al content.

According to the invention, this object is achieved by the method described in claim 1. Preferred configurations of the method according to the invention are described in the dependent claims.

According to the invention, for the production of hot rolled sheet steel products, firstly, in combination with iron and unavoidable impurities, C: 0.5% to 1.3%, Mn: 18% to 26%, Al: 5.9% To 11.5%, Si: less than 1%, Cr: less than 8%, Ni: less than 3%, Mo: less than 2%, N: less than 0.1%, B: less than 0.1%, Cu: less than 5%, Nb: 1% Steels containing less than, Ti: less than 1%, V: less than 1%, Ca: less than 0.05%, Zr: less than 0.1%, P: less than 0.04% and S: less than 0.04% are dissolved.

In the practical construction of the present invention, the content of the alloying elements Si, Cr, Ni, Mo, N, B, Cu, Nb, Ti, V, Ca, Zr, P and S is individually or combined with each other (wt% It is set as follows. 0.1% to 0.4% Si, <3.0% Cr, <1.0% Ni, <0.5% Mo, 0.005% to 0.04% N, <0.0050% B, <1% Cu, <0.2% Nb, <0.3% Ti, < 0.3% V, <0.005% Ca, <0.005% Zr, 0.01% to 0.03% P or 0.005% to 0.02% S.

The molten steel of the aforementioned composition is then cast in an essentially known manner, for example in a conventional two roller casting machine to form a casting strip.

Casting molten metal into a casting strip is known to have the advantage that segregation is reduced as a result of rapid hardening by strip casting. This is particularly preferred for high-alloy steels of the type constructed according to the invention, since the homogeneous strip properties and optimum quality of the product obtained by means of a more uniform distribution of alloying elements are achieved.

For the production of casting strips, if a conventional twin roll casting machine is used in which the casting strip advances in the vertical direction and is switched by the strand guide device in the arc-like direction to the horizontal conveying direction, the casting strip is 10K / s on the way from the casting machine to the heating device. Cooling down to an intermediate temperature of generally 700 ° C. and above at a cooling rate of from 20 K / s. According to the invention, this temperature loss is kept as small as possible, so that the casting heat inherent to the casting strip as it exits from the casting machine is kept up to the heating device to the maximum extent possible. In this way, the amount of energy required in the heating device can be minimized for the temperature increase up to the initial hot rolling temperature carried out in the heating device.

Heating of the casting strip to each hot rolling temperature in the range of 1100 ° C. to 1300 ° C. is carried out at a heating rate of at least 20 K / s according to the invention.

In this way, the casting strip heated rapidly to the initial hot rolling temperature is then hot rolled into the hot strip in one or more passes.

Cooling is initiated within 10 seconds of the end of hot rolling in accordance with the invention and the resulting hot strip is cooled at a cooling rate of at least 100 ° C. to less than 400 ° C. during the cooling. By this rapid cooling, formation of constructs having embrittlement effects such as carbides or intermetallic phases is suppressed.

Finally, the cooled hot strip is wound at a winding temperature of 400 ° C. or less to form a coil.

Each working step of the method according to the invention is carried out in a continuous sequence without interruption.

The present invention is successful in the manufacture of plate steel products with no edges or surface cracks from steel of the corresponding composition, when a thin strip of up to 5 mm, in particular 3 mm to 5 mm thick, is cast from a melt containing high content of C, Mn and Al. Based on the knowledge that Thus, the thickness of the cast strip is already within the range of the thickness that the hot rolled plate-like product produced will finally have.

The possibility to be used by the method of casting steels with high contents of C, Al and Mn in accordance with the present invention reduces the frequency of central segregation in the casting strip during the rapid solidification of the steel after strip casting and its associated casting. No lateral cracking and microcrazing occur during casting of the casting strip, and longitudinal cracking occurs only to a very limited degree. When casting a strip in a twin roll casting machine, the occurrence of central segregation can be controlled through a change in the casting machine roller force.

According to the invention, thin cast strips up to 5 mm, in particular 3 mm to 5 mm thick, already have a desired cross section with a small bending stress when leaving the roller gap. Thus, the casting strip can be bent without problems from the vertical direction to the horizontal conveying direction, passing through additional stations in the horizontal direction for processing of the strip.

At the same time, surface decarburization is considerably reduced by the use of strip casting since no hard slab heating is required anymore. By the uniform temperature distribution achieved during rapid heating carried out according to the invention before hot rolling, the risk of crack formation during hot rolling is minimized.

The casting strip according to the invention features a three-layer casting structure having a dendritic marginal zone and a globular core.

The casting strip is heated to the required initial hot rolling temperature of 1100 ° C. to 1300 ° C., using the original casting heat to its maximum when leaving the casting machine. At this time, the heating is carried out as rapidly as possible, in particular at a heating rate of at least 20 K / s.

By heating carried out according to the invention, the temperature increase achieved in the casting strip is typically at most 250 ° C. and the minimum temperature increase is typically 50 ° C. The rapid heating of the strips carried out according to the invention not only avoids the occurrence of undesirable precipitation, but also allows the temperature distribution to be set specifically over the width of the strip. Therefore, on the one hand, it is possible to make temperature distribution uniform through rapid heating. On the other hand, heating may be performed to produce a set temperature profile over the width of the casting strip in order to achieve a specific deformation behavior of the casting strip during the hot rolling process. In this way, unevenness in the strip, deviation from the directional stability and other geometrical defects in the strip can be achieved without the need for expensive additional measures.

For accelerated heating up to the initial hot rolling temperature, induction heating devices as described in DE 10323796 B3 are particularly suitable. The advantage of using an induction furnace for rapid heating or soaking of the product to be rolled is that the rolled material can be heated to a precisely settable temperature after a short time heating.

The initial hot rolling temperature reached during rapid heating is chosen such that the rolling resistance acting on the casting strip during hot rolling is minimized. In this case in particular, the initial hot rolling temperature is at least 1050 ° C. Here, the final hot rolling temperature of the hot rolling carried out according to the invention is typically in the range of 1000 ° C to 1050 ° C. This provision is based on the knowledge that the steel to be treated according to the invention has to be treated within a narrow temperature window due to the high aluminum content.

Hot rolling of strip bands carried out in-line with strip casting reduces core porosity associated with the process and material of the casting strip, improves homogeneity of the microstructure, and thus the strip as a whole Improve properties.

Due to the fact that the cast strip already has a thickness close to its final dimension before hot rolling, therefore, only a relatively low degree of deformation needs to be achieved during the hot rolling process, thus making it easier to hot roll the casting strip, which is inherently difficult to roll. Can be done. It is typically at least 10%, in particular 10% to 20%. Such a low degree of deformation can be achieved by a single pass, which also contributes to optimizing the economic efficiency of the method according to the invention.

Rapid cooling followed by hot rolling at a cooling rate of at least 100 K / s ensures that no grain growth occurs in the hot strip obtained after leaving the final hot rolling mill. Moreover, in this way in the method according to the invention, precipitation of carbides, nitrides and carbonitrides is prevented. Typically, the cooling rate achieved during cooling after hot rolling is in the range of 100 K / s to 250 K / s.

In order to reliably prevent the onset of grain growth, the cooling should be initiated as soon as possible from the end of the hot rolling if possible, and even within 10 seconds, even longer.

In order to prevent the oxidation of the molten casting and the casting strip on the way to the hot rolling apparatus, in the process according to the invention, the working steps carried out before hot rolling can be carried out under a protective gas atmosphere. The inertisation carried out in each strip casting apparatus of the meniscus region of the steel melt awaiting casting reduces the formation of an oxide coating on the surface.

The hot strips obtained according to the invention have austenite-ferrite tissues with a ferrite content of typically 5% to 50%.

Carbon can be present in the steel according to the invention in an amount of 0.5% to 1.2% by weight, in particular steels with a C content of more than 0.5% by weight. The C content is important for austenite formation and for strength grades due to solid solution hardening, increased stacking fault energy and carbide formation. In the case where the hot strip produced according to the invention is cold rolled into a cold strip, in order to improve the yield strength of the cold strip, extremely fine by a specific over-ageing treatment after the final recrystallization annealing of the cold strip. Carbide may precipitate. At C contents in excess of 1.2% by weight, there is a risk that large amounts of carbides with embrittlement effects are produced.

Manganese may be present in an amount of 18% to 26% by weight in the steel treated according to the invention. Manganese is important for the formation of austenite and increases the lamination energy with desirable effects on processability and strainability.

The steel treated according to the invention contains from 5.9% to 11.5% by weight, in particular more than 6% by weight and up to 11.5% by weight of Al. Aluminum reduces specific gravity, has a solid solution hardening effect, and increases stacking defect energy. In addition, aluminum has a passivating effect and increases its resistance to corrosion. The high content of Al results in the so-called "shear bend plasticity" as the main deformation mechanism in which the strength and deformation are particularly well-combined by very high stacking defect energy. However, too high aluminum content can result in a DO ₃ order structure that is brittle in ferrite or an excess of Al-containing k-carbide ((Fe, Mn) ₃ AlC) with an embrittlement effect.

Si can be present in the steel treated according to the invention in an amount of less than 1% by weight, in particular in an amount of 0.1% to 0.4% by weight, in order to cause solid solution hardening. However, the content of Si in excess of 1% by weight makes the welding and painting of the steel treated according to the invention more difficult.

Cr, Ni and Mo likewise have a solid solution hardening effect and improve the oxidation and corrosion protection of the steel treated according to the invention. However, at too high a content Cr forms a special carbide that can have a high embrittlement effect. As specified by the invention, the Cr content in the steel treated according to the invention is limited to less than 8% by weight, in particular less than 3% by weight, the Ni content to less than 3% by weight, in particular less than 1% by weight. If the Mo content is limited to less than 2% by weight, in particular less than 0.5% by weight, the preferred effects of Cr, Ni and Mo are best utilized.

Nitrogen forms nitrides with aluminum and has an effect of increasing strength. However, excess N results in coarse AlN which can adversely affect the treatability, surface quality and deformation of the steel treated according to the invention. Thus, the N content of the steel according to the invention is limited to N <0.1% by weight, in particular 0.005% to 0.04% by weight.

The B content of the steel according to the invention is limited to less than 0.1% by weight, in particular less than 0.0050% by weight. B has an effect of increasing strength and forms boron nitride and carbide, which act as nucleation sites for the generation of other carbides. Due to grain boundary precipitation, excess B content has an embrittlement effect.

In steels treated according to the invention, Cu has a solid solution hardening effect and increases corrosion resistance. However, if the Cu content is too high, there is a risk of hot cracking during hot rolling or hot joining. Thus, the Cu content of the steel treated according to the invention is limited to less than 5% by weight, in particular less than 1% by weight.

Micro-alloying elements Nb, Ti and V cause precipitation and grain refinement, thus contributing to the increase in strength. In addition, through the grain refinement effect, these elements reduce the tendency of the development of weld cracking of iron during hot joining. The steel treated according to the invention contains Nb, Ti or V each in a content of less than 1.0% by weight, the Nb content is particularly limited to <0.2% by weight, the Ti content is particularly limited to <0.3% by weight, and V If the content is particularly limited to <0.3 wt%, such an effect can be optimally used.

Ca in a content of less than 0.05% by weight, in particular less than 0.005% by weight, spheroidizes and improves deformability of non-metallic materials such as Al ₂ O ₃ and FeS in the steel treated according to the invention. Formation of Ca aluminite changes alumina into slag and improves purity.

Zr has a solid solution hardening effect at a content of less than 0.1% by weight, in particular less than 0.005% by weight in the steel treated according to the invention. However, due to grain boundary segregation, Zr also has an embrittlement effect, so that the content of this element in the steel according to the present invention is limited.

P and S segregate at grain boundaries within the steel treated according to the invention and have an embrittlement effect. Therefore, the content should be as low as possible and especially less than 0.04% by weight, the P content is preferably 0.01% to 0.03% by weight, and the S content is preferably 0.005% to 0.02% by weight.

In order to ensure the optimum deformability of the hot strips obtained according to the invention, hot strip annealing is carried out after winding and before further treatment, and during annealing the hot strips obtained according to the invention are annealed at annealing temperatures of 1100 ° C to 1200 ° C. If hot strip annealing is carried out in a continuous annealing furnace, this requires an annealing time of 60 to 300 seconds. Such hot strip annealing is useful, in particular if the Al content of the steel treated according to the invention is at least 10% by weight. In such high Al contents, in order to prevent the formation of brittle phases, it is useful to carry out cooling as soon as possible after the hot rolling, in particular at a cooling rate of at least 40 K / s.

The hot strips obtained according to the invention can optionally be pickled in a conventional manner after winding and can be used with or without coating. Similarly, after pickling optionally carried out in an essentially known manner, it is possible to coat the hot strip produced according to the invention with a metal protective coating, for example a corrosion-proofing coating. It is also contemplated to provide a coating in the hot rolled plate-shaped article produced according to the invention to simplify the deformation of the hot strip.

In the procedure according to the invention, it is also possible to cold roll the hot strip obtained according to the invention to form a cold strip product, which is then subjected to recrystallization annealing, super-aging annealing (precipitation hardening with fine carbides) and Various types of surface refinements (Z, ZE, ZN, FAL) can be subjected. Here, for example, cold rolling and subsequent recrystallization annealing densify and homogenize the microstructure of the central region.

If thinner plate steel products are needed, the hot strips made according to the invention thus allow the cold strips to be treated in one or more passes in an essentially known manner. If the product needs to be protected against environmental influences, it can also be surface coated as needed.

Since the strip has already been cast close to the final dimension, and only a few relevant deformations are required during hot and cold rolling, the essentially high resistance to hot and cold rolling of the steel treated according to the invention has only minor effects. This makes it possible to produce plate-shaped products of small thickness from such steels treated according to the invention, even if they are of the type of steel in question in the rolling process.

1 is a schematic diagram of a production line for producing hot strips.

Hereinafter, the present invention will be described in more detail using embodiments.

The figure is a schematic diagram of a production line 1 for producing a hot strip W.

The production line 1 installed for a continuous manufacturing process is characterized by the fact that the molten metal S has a casting strip typically having a thickness of 3 mm to 5 mm in a gap delimited by two rollers 2 and 3 rotating in opposite directions. And a conventional twin roll casting machine (1) cast to G). The casting strip G advancing in the vertical direction is converted in the horizontal conveying direction F through the strand guiding device in essentially the same way as is known and forwarded by the conveyor device 4 disposed at the end of the strand guiding device. Is transferred to.

The casting strip G, which is aligned in this way and moves in the conveying direction F, enters the heating device 5. On the way to the heating device 5, the casting strip G is cooled to an intermediate temperature at a cooling rate of 10 K / s to 20 K / s.

The casting strip G entering the intermediate temperature in the heating device 5 is typically in the range 1100 ° C. to 1300 ° C., in particular at least 1150, by an inductor 6 laterally aligned with respect to the conveying direction F. Induction heating up to an initial hot rolling temperature of ° C.

By means of the electromagnetic field produced by the inductor 6, the temperature increase of the casting strip G achieved by passing through the heating device is at most 300 ° C., typically 50 ° C. to 150 ° C. At this time, the inductor 6 as described, for example, in German patent publication DE 103 23 796 B3, on the one hand, has a defined temperature profile so that the casting strip G is heated evenly over the entire width. It can be adjusted and controlled to be set in this casting strip G.

In order to prevent the molten metal S and the casting strip G from contacting the surrounding atmosphere U, the twin roll casting machine 1, the strand guide device, the conveyor device 4, and the heating device 5 have a protective gas atmosphere ( S) can be maintained.

After the heating device 5, the casting strip G enters the rolling mill 9 and is rolled into a hot strip, typically 2.4 mm to 4.5 mm thick, by a single pass. At this time, the final hot rolling temperature at which the hot strip W leaves the final mill 9 in the conveying direction F is generally in the range of 1000 ° C to 1050 ° C. The degree of deformation achieved through one feed roller is generally in the range of 10% to 30%.

Within 10 seconds after leaving the mill 9, the resulting hot strip W is cooled in the cooling device 10 to a winding temperature in the range of 300 ° C to 400 ° C, typically at a cooling rate of 100K / s to 200K / s, At the coiling temperature, the hot strip W is wound into the coil C by the winding device 11.

Hot strip annealing may be performed subsequent to winding in a heat treatment apparatus not shown in the figures.

In the production line 1 in the manner described above, four hot strips are produced from the molten metals S1 to S3, the composition of which is shown in Table 1.

The strip G cast from each of the molten metals S1 to S3 is cooled in each case at a cooling rate of approximately 15 K / s on the way to the heating device 5, and each initial hot rolling temperature in the heating device 5. It is heated up to WAT by a temperature increase ΔT and is hot rolled into a hot strip W of thickness dWB in each case in three passes with a total strain of phi g and a final rolling temperature of WET in the hot rolling mill 9. In each case immediately after the hot strip W is cooled to the respective winding temperature HAT at the cooling rate tK, it is wound up in the coil C in each case at the winding temperature. The parameters ΔT, WAT, WET, φg, dW, tK and HAT expressed in each case in the treatment of the strip G cast from steels S1 to S3 are listed in Table 2.

The hot strip made from steel S3 is also subjected to hot strip annealing for 120 seconds at 1100 ° C. in a continuous annealing furnace after winding. In this way, even in hot strips made from this steel S3, surface defects can be reliably prevented, despite the high C, Mn and Al contents.

Table 3 shows the hot strip thickness (dWB), specific gravity (ρWB), yield strength (Rp0.2), together with the structure of the hot strips produced from the steels S1 to S3 by the process according to the invention described herein. , Mechanical properties of tensile strength (Rm), elongation (A80), n-value, and r-value.

1: manufacturing line 2,3: casting roller
4: conveying device 5: heating device
6: induction machine 9: rolling mill
10: cooling device 11: winding device
A: protective gas atmosphere C: coil
F: Feed direction G: Casting strip
S: Molten U: Waiting around
W: hot strip

Claims (14)

In weight percent, with iron and unavoidable impurities,
C: 0.5% to 1.3%,
Mn: 18% to 26%,
Al: 5.9%-11.5%,
Si: less than 1%,
Cr: less than 8%,
Ni: less than 3%,
Mo: less than 2%,
N: less than 0.1%,
B: less than 0.1%,
Cu: less than 5%,
Nb: less than 1%,
Ti: less than 1%,
V: less than 1%,
Ca: less than 0.05%,
Zr: less than 0.1%,
P: less than 0.04%,
S: melting the molten steel (S) containing less than 0.04%,
Casting the molten steel S into a casting strip G,
Heating the casting strip (G) at a heating rate of at least 20 K / s to an initial hot rolling temperature of 1100 ° C.-1300 ° C.,
Hot rolling the cast strip G heated to the initial hot rolling temperature into a hot strip W;
Starting the cooling of the hot strip W within 10 seconds after hot rolling to cool it to below 400 ° C. at a cooling rate of at least 100 K / s,
Winding the cooled hot strip (W) with the coil (C) at a coiling temperature of up to 400 ° C. The method of claim 1,
The molten steel, in weight percent, from 0.1% to 0.4% Si, less than 3.0% Cr, less than 1.0% Ni, less than 0.5% Mo, 0.005% to 0.04% N, less than 0.0050% B, 1% Less than Cu, less than 0.2% Nb, less than 0.3% Ti, less than 0.3% V, less than 0.005% Ca, less than 0.005% Zr, 0.01% to 0.03% P, or 0.005% to 0.02% S A method for producing a hot rolled plate steel product, characterized in that it comprises a. 10. A method according to any one of the preceding claims,
Casting of the molten steel to a casting strip (G) is carried out in a twin roll casting machine. 10. A method according to any one of the preceding claims,
A method for producing hot rolled sheet steel products, characterized in that the thickness of the cast strip (G) is at most 5 mm. 10. A method according to any one of the preceding claims,
Accelerated heating up to the initial hot rolling temperature is carried out by an induction actuated heating device (5). 10. A method according to any one of the preceding claims,
The initial hot rolling temperature at which the cast strip (G) is heated is at least 1150 ° C. A method for producing a hot rolled sheet steel product. 10. A method according to any one of the preceding claims,
A method for producing a hot rolled sheet steel product, characterized in that the degree of deformation achieved during hot rolling is at least 10%, in particular 10% to 20%. 10. A method according to any one of the preceding claims,
The final hot rolling temperature of the hot rolling is from 1000 ° C. to 1050 ° C. 10. A method according to any one of the preceding claims,
Hot rolling is performed in a single pass. 10. A method according to any one of the preceding claims,
Accelerated cooling of the hot strip (W) is initiated within 10 seconds of the end of the hot rolling. 10. A method according to any one of the preceding claims,
The steps carried out before hot rolling are carried out under a protective atmosphere (A). 10. A method according to any one of the preceding claims,
The obtained hot strip (W) is subjected to hot strip annealing at an annealing temperature of 900 ° C to 1150 ° C. The method of claim 12,
The Al content of the cast strip (G) is at least 10% by weight. 10. A method according to any one of the preceding claims,
The hot strip (W) is cold rolled into a cold strip to produce a hot rolled sheet steel product.

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