WO2020169764A1

WO2020169764A1 - Steel product made of lightweight steel containing manganese and method for production thereof

Info

Publication number: WO2020169764A1
Application number: PCT/EP2020/054536
Authority: WO
Inventors: Zacharias Georgeou; Manuel Otto
Original assignee: Salzgitter Flachstahl Gmbh
Priority date: 2019-02-22
Filing date: 2020-02-20
Publication date: 2020-08-27
Also published as: EP3927862A1; DE102019104597A1

Abstract

The invention relates to a steel product made of lightweight steel containing manganese, having a minimum notched bar impact work at -40 °C in the transverse direction of ≥ 20 Joules, preferably at least 30 Joules, having the following chemical composition in wt.%: C: 0.1 to 1.8, preferably 0.3 to 1.5; Mn: 15 to 35, preferably 20 to 30; Al: 6 to 12, preferably 7 to 10; Si: 0.2 to 1.5, preferably 0.5 to 1.2; Mo: 0.1 to 1.2, preferably 0.5 to 1.1; V: 0.05 to 0.5, preferably 0.07 to 0.3; Nb: 0.01 to 0.5, preferably 0.05 to 0.3; Cr: 0.05 to 3, preferably 0.1 to 2; Ni; 0.05 to 3, preferably 0.1 to 2; P: < 0.04; S: < 0.02; N: < 0.02; remainder iron, including unavoidable elements accompanying steel, together with the optional addition of one or more of the following elements: Ti, Cu, B, Co, W, Zr, Ca and Sn, having a joint consisting of at least 40 vol.% austenite, less than 60 vol.% ferrite, remainder martensite and/or carbides up to 2%, consisting of kappa carbides and/or vanadium carbides and/or niobium carbides and/or molybdenum carbides having a good combination of strength, distension and forming properties. The invention further relates to a method for producing a steel product in the form of a flat steel product made from the aforementioned lightweight steel containing manganese.

Description

Steel product made from lightweight structural steel containing manganese and process for its

Manufacture The invention relates to a steel product made of manganese-containing lightweight steel with a minimum impact energy at -40 ° C. in the transverse direction of> 20 joules, preferably> 30 joules, and a process for its production in the form of a flat steel product or a seamless tube. The term “armor” is also used as a synonym for such steel products. In the following, “steel products” refers in particular to hot-rolled products such as heavy plate with thicknesses of around 3 mm to 250 mm and also hot-rolled products

Cold strip with thicknesses of about 0.5 mm to 25 mm as well as welded pipes made therefrom, but also seamless pipes.

In particular, the invention relates to the production of a steel product from a manganese-containing lightweight steel with excellent low-temperature toughness and / or high strength, in which a notch impact work in the transverse direction of at least 20 joules, preferably at least 30 joules, can be achieved even at minus 40 ° C. (TRansformation Induced Plasticity) and / or TWIP (TWinning Induced Plasticity) effect.

In general, corresponding steel products should have a high energy absorption capacity at low temperatures and sudden loads, i.e. they should absorb the impact energy as completely as possible. In the best-case scenario, for example, the projectile should get stuck in the armor during a fire, i.e. not penetrate through the armor. In addition, the plastic deformation of the armor by an incoming projectile should not lead to excessive elongation of the steel product. But even in the event of a crash, the material should still be sufficiently tough at low temperatures.

Steels and steel products made from them with a high

The ability to absorb energy in the event of sudden stress, in particular in the event of bombardment or blasts, has long been known. For example, the utility model DE 7138758 U discloses a bulletproof armor for Motor vehicles that consist of an outer, preferably surface-hardened

Steel plate and a plastic layer arranged behind it.

The laid-open specification DE 10 2016 108 278 A1 discloses a multi-layer, strip-shaped composite material made of steel with an applied thereto

Non-metal layer that should be bulletproof. This known armor made of steel is very complex to manufacture and therefore expensive due to the additional non-metallic coatings required.

From the published patent application DE 10 2005 023 952 A1 there is also one

Safety armor for protection against fire is known, which is enriched in the edge zone on the fire side with at least 0.5 mass% with carbon and has a minimum hardness of 55 HRC on the top surface. This armoring has disadvantages in particular due to the high carbon content on the firing side, which significantly reduces the weldability.

A lightweight structural steel containing manganese, which is said to have excellent plasticity at low temperatures down to -150 ° C., is known from laid-open specification EP 0 889 144 A1. The austenitic lightweight steel has the following

Alloy composition in% by mass: 1 to 6% Si, 1 to 8% Al with (Al + Si) £ 12%, 10 to 30% Mn, the remainder essentially iron, including the usual

Steel accompanying elements.

From the European patent application EP 2 641 987 A2 are a

medium-manganese high-strength steel and a method for producing this steel are known. The steel has a notched impact strength of 70 J at -196 ° C and consists of the elements (contents in% by weight and based on the

Molten steel): C: 0.01 to 0.06; Mn: 2.0 to 8.0; Ni: 0.01 to 6.0; Mo: 0.02 to 0.6; Si: 0.03 to 0.5; AI: 0.003 to 0.05; N: 0.0015 to 0.01; P: up to 0.02; S: up to 0.01; and the remainder iron and unavoidable impurities. This steel is said to be distinguished by the fact that it is more cost-effective to manufacture than the steels containing up to 9% by weight of nickel that have been used up to now for this purpose. A method for producing a steel product from the above-described high-strength medium-manganese steel comprises the following work steps:

Heating a steel slab to a temperature of 1000 ° C to 1250 ° C, rolling of the slab with a rolling end temperature of 950 ° C or less with a

Reduction rate (rolling degree) of 40% or less, cooling the rolled steel to a temperature of 400 ° C or less at a cooling rate of 2 ° K / sec or more, and subsequent to the cooling, tempering the steel for 0.5 hour to 4 hours at a temperature between 550 ° C and 650 ° C. The structure of the steel shows as

Main phase martensite and 3 to 15 vol .-% residual austenite. In terms of lightweight construction in combination with adequate toughness at low temperatures, this steel is not yet optimally designed.

Proceeding from this, the present invention is based on the object of specifying a steel product made from a manganese-containing lightweight structural steel with an increased density reduction compared to iron, which has a high

Energy absorption capacity in the event of sudden stress and depth

Having temperatures.

In addition, the steel product should be inexpensive to manufacture using a suitable method and should be an advantageous combination of strength and strength properties

Have elongation properties at low temperatures and optionally a TRIP and / or TWIP effect. In particular, a notched impact energy in the transverse direction of at least 20 joules, preferably at least 30 joules, should be achieved at a temperature of -40 ° C.

This object is achieved by a steel product according to the invention having the features of claim 1. Advantageous embodiments of the invention are specified in the subclaims. A method according to the invention for producing such a steel product is specified with the features of claim 9 and its subclaims.

According to the invention, a steel product made of manganese-containing, in particular density-reduced lightweight structural steel with high energy absorption capacity in the event of sudden loads and low temperatures with a minimum impact energy at -40 ° C in the transverse direction of> 20 joules, preferably at least 30 joules, with the following chemical composition in% by weight: C: 0.1 to 1.8, preferably 0.3 to 1.5; Mn: 15 to 35, preferably 20 to 30; AI: 6 to 12, preferably 7 to 10; Si: 0.2 to 1.5, preferably 0.5 to 1.2; Mo: 0.1 to 1.2, preferably 0.5 to 1.1; V: 0.05 to 0.5, preferably 0.07 to 0.3; Nb: 0.01 to 0.5, preferably 0.05 to 0.3; Cr: 0.05 to 3, preferably 0.1 to 2; Ni: 0.05 to 3, preferably 0.1 to 2; P: <0.04; S: <0.02; N: <0.02; The remainder iron including unavoidable elements accompanying steel, with the optional addition of one or more of the following elements: Ti, Cu, B, Co, W, Zr, Ca and Sn, having a structure consisting of at least 40% by volume of austenite, less than 60 Vol .-% ferrite, remainder martensite and / or carbides up to 2%, consisting of k-carbides and / or vanadium and / or niobium and / or molybdenum carbides a good combination of strength, elongation and

Forming properties. The impact energy is determined in accordance with DIN EN ISO 148-1.

In addition, the production of this manganese-containing according to the invention

Steel product based on the alloy elements C, Mn, Al, Mo and Si cost-effective, since an increased addition of nickel of up to 9% by weight to achieve the low-temperature toughness can generally be dispensed with. The steel product according to the invention is significantly reduced in density compared to known Ni-containing steels and is therefore lighter and has a stable austenite content even at low temperatures down to at least -40 ° C, which converts at the earliest when deformed at low temperatures, but is otherwise metastable to stable. This austenite content of at least 40% by volume, which is present at the low temperatures, improves the low-temperature toughness and thus the

Elongation properties.

The steel product according to the invention can advantageously be used as a substitute for steels with a high Ni content in low-temperature applications and sudden loads, such as in the civil or military sector.

The optionally alloyed elements advantageously have the following contents in% by weight: Ti: 0.002 to 0.5; Cu: 0.05 to 2; B: 0.0005 to 0.014; Co: 0.003 to 3; W: 0.03 to 2; Zr: 0.03 to 1; Ca: <0.004 and Sn: <0.5.

The steel product according to the invention has a multiphase structure, consisting of at least 40% by volume, preferably at least 70% by volume, particularly preferably at least 90% by volume of austenite, less than 40% by volume, preferably less than 20% by volume % Ferrite, the rest martensite and / or carbides. The carbides can be used as kappa (K) carbides and / or vanadium and / or niobium and / or molybdenum carbides are present. A minimum ferrite content of 2% by volume is preferred. It is advantageously provided that a portion of at least 0.5% of the carbides is present as kappa and / or vanadium and / or niobium and / or molybdenum carbides.

A part of the austenite from 5% up to 90% can be in the form of annealing or

There are deformation twins. The lightweight steel can optionally have both a TRIP and a TWIP effect, with part of the austenite being able to partially convert into martensite during a subsequent deformation / forming / processing of the steel strip, whereby at least 80% of the original austenite must be retained in order to achieve the To ensure low temperature properties.

The crystal structure of the kappa carbides is a perovskite structure in which C is octahedral surrounded by Fe and Mn and in which Al is located at the corners of the unit cell. The k-phase is typically substoichiometric with respect to C and AI. C leaves voids and Al is exchanged for Fe or Mn. If there is no C, this corresponds to the fcc order structure L1 ₂ (Fe, Mn) ₃ AI).

In two-phase Gamma-Kappa steels, Fe-Mn-Al-C based alloys, nanoscale, coherent Kappa carbide precipitates, which can be solidified, combine a low density with high ductility, strength and thermal stability, which has an advantageous effect on the required properties of the Steel product. The addition of the elements Nb, V or Mo results in an order structure L1 ₂ (Fe, Mn, X) AI) (with = Nb, V or Mo) through partial substitution of Fe or Mn and intensifies the beneficial effect on the required product properties.

The steel product according to the invention is also distinguished by an increased resistance to delayed crack formation (delayed fracture) and to hydrogen embrittlement. This is mainly achieved through the precipitation of molybdenum carbide, which acts as a hydrogen trap. In addition, the steel has a high resistance to it

Liquid metal embrittlement (LME) during welding.

The use of the term “to” in the definition of the content ranges, such as 0.01 to 1% by weight, means that the benchmarks - in the example 0.01 and 1 - are included.

The steel according to the invention is particularly suitable for producing heavy plate or hot and cold strip, as well as components such as welded and seamless pipes, which can be provided with metallic or non-metallic, organic or other inorganic coatings. The coatings can be of the same type or a mixture of several layers.

The steel product advantageously has a yield strength Rp0.2 of 550 to 1200 MPa, a tensile strength Rm of 670 to 1500 MPa and a

Elongation at break A50 of more than 25% to 80%, with higher tensile strengths tending to be associated with lower elongation at break and vice versa. The solution heat treatment according to the invention achieves elongation limits Rp0.2 of 550 to 750 MPa, tensile strength Rm of 670 to 860MPa and an elongation at break A50 of 67% to 80% at room temperature. With regard to the invention, to the

Additional solution heat treatment, hardening annealing, achieves a yield strength Rp0.2 of 780 to 1200 MPa, a tensile strength Rm of 870 to 1500 MPa and an elongation at break A50 of more than 25% to 77% at room temperature. According to the invention, a steel product in the form of a flat steel product, such as hot strip, cold strip, heavy plate or a component thereof, is supplied by a method comprising the steps: Method for producing a

Steel product in the form of a flat steel product or a component, comprising the steps:

- Melting a steel melt with the following chemical composition in

% By weight: C: 0.1 to 1.8, preferably 0.3 to 1.5; Mn: 15 to 35, preferably 20 to 30; AI: 6 to 12, preferably 7 to 10; Si: 0.2 to 1.5, preferably 0.5 to 1.2; Mo: 0.1 to 1.2, preferably 0.5 to 1.1; V: 0.05 to 0.5, preferably 0.07 to 0.3; Nb: 0.01 to 0.5, preferably 0.05 to 0.3; Cr: 0.05 to 3, preferably 0.1 to 2; Ni: 0.05 to 3, preferably 0.1 to 2; P: <0.04; S: <0.02; N: <0.02; The remainder iron including unavoidable elements accompanying steel, with the optional addition of one or more of the following elements: Ti, Cu, B, Co, W, Zr, Ca and Sn, via the process route

Blast furnace steel mill or the electric arc furnace process each with optional

Vacuum treatment of the melt,

- Pouring the steel melt to a pre-strip by means of a near-net-shape horizontal or vertical strip casting process or casting the molten steel into a slab or thin slab using a horizontal or vertical slab or thin slab casting process,

- Heating to a hot rolling start temperature of 1050 ° C to 1250 ° C or utilizing the casting heat to achieve the hot rolling start temperature of 1050 ° C to 1250 ° C (inline rolling),

- Hot rolling of the pre-strip or the slab or the thin slab into a heavy plate with a thickness of over 3 to 200 mm or a hot strip with a thickness of 0.8 to 28 mm, each with a rolling end temperature of 650 ° C to 1050

° C,

- Coiling of the hot strip at a temperature of more than 100 ° C to 600 ° C,

- optional pickling of the hot strip,

Depending on whether a hot strip, cold strip, heavy plate or a component is to be produced from it as an end or intermediate product, individual or combinations of the following steps follow:

- Solution annealing of the heavy plate or hot strip in an annealing plant with an annealing time of 0.1 h to 24 h, preferably 0.3 h to 24 h, and temperatures of 1000 ° C to 1100 ° C, preferably 1030 ° C to 1080 ° C with an annealing time of 0.5 h to 6 h, then quenching at a cooling rate of more than 5 ° C. per second, then tempering at temperatures of 500 ° C. to 550 ° C., preferably 520 ° C. to 540 ° C. with an annealing time from 10 h to 20 h, preferably 13 h to 18 h (end or intermediate product: heavy plate or hot strip),

and or

- Cold rolling of the previously solution-annealed or non-solution-annealed hot strip at room temperature or at an elevated temperature before the first rolling pass in one or more rolling passes to a thickness of £ 3 mm with a degree of rolling of 10% to 90%, preferably 30% to 60%,

- Solution annealing of the cold strip in an annealing plant with an annealing time of 0.2 h to 24 h and temperatures of 500 ° C to 850 ° C, preferably 520 ° C to 600 ° C with an annealing time of 0.3 h to 6 h (End - or intermediate product: cold strip),

and or

- Further processing of the previously solution annealed or not solution annealed

Cold strip, heavy plate or hot strip to form a component, in particular a longitudinally or spiral seam welded pipe,

- Solution annealing of the component in an annealing plant with an annealing time of 0.2 h to 24 h and temperatures of 500 ° C. to 850 ° C., preferably 520 ° C. to 600 ° C. with an annealing time of 0.5 h to 6 h (end product: component).

The end or intermediate product, such as hot strip, cold strip, heavy plate or a component made from it, has a good combination of strength, elongation and deformation properties.

It is preferably provided that the heavy plate, hot strip, cold strip or component is heated in an annealing system at an annealing time of 10 s to 120 s, preferably 15 s to 90 s, and temperatures of 550 ° C to 850 ° C, preferably 550 ° C to 650 ° C ° C,

is age hardening annealed.

The heavy plate, hot strip, cold strip or component is advantageously solution annealed and / or age hardening annealed in an annealing plant with an atmosphere of argon or an argon-hydrogen mixture.

In the case of further processing of the flat steel product into a component, such as a longitudinally or spiral seam welded pipe, the solution heat treatment required to achieve the required low-temperature toughness and thus the setting of the final structure can not be carried out on the hot or cold strip, but optionally only after the pipe has been manufactured. If necessary, the tube can be given an organic or inorganic coating on one or both sides after annealing, or it can be electrolytically galvanized or hot-dip galvanized.

With regard to further advantages, reference is made to the above statements on the steel according to the invention.

The usual thickness ranges for pre-strip are 1 mm to 35 mm and for slabs and thin slabs 35 mm to 450 mm. It is preferably provided that the slab or thin slab is hot-rolled into a heavy plate with a thickness of more than 3 mm to 200 mm or a hot strip with a thickness of 0.8 mm to 28 mm, or the pre-strip cast close to its final dimensions is hot-rolled into a hot strip with a thickness of 0.8mm to 3mm is hot rolled. The cold strip according to the invention has a thickness of at most 3 mm, preferably 0.1 mm to 1.4 mm. In connection with the above inventive method, a Semi-finished strip produced with the two-roll casting process with a thickness of less than or equal to 3 mm, preferably 1 mm to 3 mm, already understood as hot strip. The pre-strip produced in this way as hot strip does not have an original cast structure due to the reshaping of the two counter-rotating rolls. Hot rolling thus already takes place inline during the two-roll casting process, so that separate hot rolling can optionally be omitted.

The cold rolling of the hot strip can take place at room temperature or advantageously at an elevated temperature before the first rolling pass, in one or more rolling passes.

Cold rolling at elevated temperatures is advantageous in order to reduce the rolling forces and to promote the formation of deformation twins (TWIP effect). Advantageous temperatures of the rolling stock before the first rolling pass are 60 ° C to 450 ° C.

If necessary, the cold strip can be skin-pass after cold rolling, whereby the surface structure (topography) required for the end application is set. Passing can be done, for example, using the Pretex® process.

In an advantageous development, the flat steel product or component produced in this way is given a surface refinement, for example by electrolytic galvanizing or hot-dip galvanizing and, instead of galvanizing or in addition, a coating on an organic or inorganic basis. The coating systems can be, for example, organic coatings, plastic coatings or lacquers or other inorganic coatings such as iron oxide layers.

The flat steel product produced according to the invention can be used both as sheet metal,

Sheet metal section or blank can be used or processed into a component such as a longitudinally or spiral-welded pipe.

In connection with the aforementioned method, it is expressly pointed out that the method steps specified as optional, all or each Subcombinations of this can also be provided for in the process.

Warm forming or warm internal high pressure forming is the term used here for forming and internal high pressure forming processes in which at least the first forming step takes place at a temperature above room temperature to below the Ac3 temperature, preferably at 60 ° C to 450 ° C.

Below, in Table 1, chemical compositions of non-inventive manganese-containing lightweight steels M1 to M4 and of manganese-containing lightweight steels L1 to L2 according to the invention are given in% by weight. For the lightweight steels M1 to M4 and L1 to L2, the microstructure achieved in the form of the presence of ferrite (a), austenite (g) and / or carbides (K) is specified, as well as the impact energy determined for this in the transverse direction in accordance with DIN EN ISO 148 -1 in joules at -40 ° C.

The lightweight steels M1 to M4 and L1 to L2 are previously solution-annealed at a temperature of 550 to 650 ° C in an annealing system with an atmosphere of argon or an argon-hydrogen mixture and then in an annealing system with an atmosphere of argon or an Argon-hydrogen mixture

has been age hardened.

Claims

1. Steel product made from lightweight structural steel containing manganese with a minimum impact energy at -40 ° C in the transverse direction of> 20 joules, preferably> 30 joules, with the following chemical composition in% by weight:

C: 0.1 to 1.8, preferably 0.3 to 1.5;

Mn: 15 to 35, preferably 20 to 30;

AI: 6 to 12, preferably 7 to 10;

Si: 0.2 to 1.5, preferably 0.5 to 1.2;

Mo: 0.1 to 1.2, preferably 0.5 to 1.1;

V: 0.05 to 0.5, preferably 0.07 to 0.3;

Nb: 0.01 to 0.5, preferably 0.05 to 0.3;

Cr: 0.05 to 3, preferably 0.1 to 2;

Ni: 0.05 to 3, preferably 0.1 to 2;

P: <0.04;

S: <0.02;

N: <0.02;

The remainder iron including unavoidable elements accompanying steel, with the optional addition of one or more of the following elements: Ti, Cu, B, Co, W, Zr, Ca and Sn, having a structure consisting of at least 40% by volume of austenite, less than 60 Vol .-% ferrite, the remainder martensite and / or carbides up to 2%, consisting of kappa carbides and / or vanadium and / or niobium and / or molybdenum carbides.

2. Steel product according to claim 1, characterized in that the structure of the steel product has an austenite content of at least 70% by volume, preferably at least 90% by volume, a ferrite content of less than 20% by volume.

3. Steel product according to claim 2, characterized in that the ferrite content is at least 2% by volume.

4. Steel product according to at least one of claims 1 to 3, characterized

characterized in that a part of at least 0.5% of the carbides is present as kappa and / or vanadium and / or niobium and / or molybdenum carbides.

5. Steel product according to at least one of claims 1 to 4, characterized characterized in that a proportion of 5% up to 90% of the austenite is in the form of annealing or deformation twins.

6. Steel product according to at least one of claims 1 to 5, characterized

characterized that the lightweight steel has a yield strength Rp0.2 from 550 MPa to 1200 MPa, a tensile strength Rm from 670 MPa to 1500 MPa and a

Has elongation at break A50 of more than 25% to 80%.

7. Steel product according to at least one of claims 1 to 6, characterized

characterized in that the steel product has a metallic, inorganic or organic coating and optionally one or more further metallic, other inorganic or organic coatings are applied to the coating.

8. Steel product according to at least one of claims 1 to 6, characterized

characterized in that the optional addition of one or more of the following elements: Ti, Cu, B, Co, W, Zr, Ca and Sn takes place in each case with the following content (s) in% by weight: Ti: 0.002 to 0.5 ; Cu: 0.05 to 2; B: 0.0005 to 0.014; Co: 0.003 to 3; W: 0.03 to 2; Zr: 0.03 to 1; Ca: <0.004 and Sn: <0.5.

9. A method for producing a steel product, comprising the steps:

- Melting a steel melt according to at least one of claims 1 to 8 via the process route blast furnace-steelworks or the electric arc furnace process, in each case with optional vacuum treatment of the melt,

- Pouring the steel melt to a pre-strip by means of a

Near-net-shape horizontal or vertical strip casting process or casting of the steel melt to form a slab or thin slab using a horizontal or vertical slab or thin slab casting process,

- heating to a hot rolling start temperature of 1050 ° C to 1250 ° C or utilizing the casting heat to achieve the hot rolling start temperature of 1050 ° C to 1250 ° C,

- Hot rolling of the pre-strip or the slab or the thin slab into a heavy plate with a thickness of more than 3 mm to 200 mm or a hot strip with a thickness of 0.8 mm to 28 mm, each with a final rolling temperature of 650 ° C to 1050 ° C, - Coiling of the hot strip at a temperature of more than 100 ° C to 600 ° C,

- optional pickling of the hot strip,

- Solution annealing of the heavy plate or the hot strip in an annealing plant with an annealing time of 0.1 h to 24 h and temperatures of 1000 ° C to 1100 ° C, preferably 1030 ° C to 1080 ° C with an annealing time of 0.5 h to 6 h, then quenching at a cooling rate of more than 5 ° C. per second, then tempering at temperatures of 500 ° C. to 550 ° C., preferably 520 ° C. to 540 ° C. with an annealing time of 10 h to 20 h, preferably 13 h up to 6 p.m.,

and or

- Solution annealing of the cold strip in an annealing plant with an annealing time of 0.2 h to 24 h and temperatures of 500 ° C to 850 ° C, preferably 520 ° C to 600 ° C with an annealing time of 0.3 h to 6 h,

and or

Cold strip, heavy plate or hot strip into one component,

Solution annealing of the component in an annealing plant with an annealing time of 0.2 h to 24 h and temperatures of 500 ° C. to 850 ° C., preferably 520 ° C. to 600 ° C. with an annealing time of 0.5 h to 6 h.

10. The method according to claim 9, characterized in that the heavy plate, hot strip, cold strip or component in an annealing system with an annealing time of 10 s to 120 s, preferably 15 s to 90 s, and temperatures of 550 ° C to 850 ° C, preferably 550 ° C to 650 ° C, age-hardening annealed.

11. The method according to claim 9 or 10, characterized in that the

Heavy plate, hot strip, cold strip or component in an annealing line with a

An atmosphere of argon or an argon-hydrogen mixture is solution annealed and / or age-hardening annealed.

12. The method according to at least one of claims 9 to 11, characterized

characterized in that the first rolling pass occurs when the hot strip is cold-rolled at a temperature of 60 ° C to 450 ° C.

13. The method according to at least one of claims 9 to 12, characterized

marked that the cold strip is being passed.

14. The method according to at least one of claims 9 to 13, characterized

characterized in that the cold strip or component is electrolytically galvanized, hot-dip galvanized or coated with an organic or inorganic coating.

15. The method according to at least one of claims 9 to 14, characterized

characterized that the component is a longitudinally welded or

spiral welded pipe is.