FI123847B - METHOD FOR THE MANUFACTURE OF MEDIUM-CARBON STEEL AND HOT-ROLLED MEDIUM-STEEL - Google Patents

Abstract

The invention relates to a method for manufacturing a medium carbon steel product from a steel billet and to a hot rolled medium carbon steel product containing Fe, unavoidable impurities and residual contents. The hot rolled medium carbon steel product containing Fe, unavoidable impurities and residual contents, contains in terms of percentages of mass, at least the following C 0.3 to 0.7 %, Si 0.05 to 2.0 %,Mn 0.2 to 2.0 %, Cr 0.5 to 3.0 %, V less than 1.0 %, Ni 1.0 to 6.0 %, Mo less than 1.0 %, wherein, in terms of percentages of mass, C + Ni + Cr + Mo is 2.8 to 5.5 %.

Description

METHOD FOR THE MANUFACTURE OF MEDIUM-CARBON STEEL AND HOT-ROLLED MEDIUM-STEEL

Field of the Invention

The invention relates to a process for manufacturing a medium carbon steel product, such as tool steel, from a steel blank as defined in the preamble of independent claim 1.

The invention also relates to a hot rolled medium carbon steel product, e.g., iron Fe and tool steel containing inevitable impurities and residual contents as defined in the preamble of independent claim 25.

Traditionally, tool steels have been produced by forging, and flat-rolled tool steels have been manufactured by hardening and allowing steel plates in furnaces. Hardening should be done carefully and relatively slowly using salt baths or air cooling. In order to be possible, such manufacturing methods require additional ingredients for the steel blank.

Objective of the Invention

It is an object of the invention to provide an economical and efficient method for producing a hot rolled medium carbon steel product, such as tool steel.

Another object of the invention is to provide a hot rolled medium carbon steel which can be produced by intermittent quenching in a hot rolling line.

Brief Description of the Invention The method of the invention is known from the definitions of independent claim 17.

Preferred embodiments of the method are defined in dependent claims I to 2 to 24.

c) The hot rolled medium carbon steel product of the invention is known as O)

LO

Lo as defined in independent claim 25.

Preferred embodiments of the hot rolled medium carbon steel product are defined in the dependent claims 26-39.

According to a first aspect of the invention, the process includes a step 2 for obtaining a steel blank, a hot rolling step, a first cooling step after the hot rolling step, a holding step after the first cooling step, and a second cooling step after the holding step.

The first step of the process is the step of providing a steel blank containing 0.3 to 0.7% by weight of carbon, C, and Fe, inevitable impurities and residual contents.

The second step of the process is a hot rolling step for hot rolling a steel blank at a temperature in the range of 800 to 1250 ° C to obtain a hot rolled steel blank.

The third step of the process is a first cooling step after the hot rolling step, wherein the hot rolling billet is cooled, preferably quenched, to a temperature at least at a cooling rate corresponding to a critical cooling rate (CCR) of Ms-570 ° C, preferably Md-570 ° C. In this first cooling step, the hot-rolled steel billet is cooled, preferably quenched, directly or indirectly, after the hot-rolling step, to a temperature below the austenitic to ferrite conversion temperature but above the martensite start temperature (Ms), preferably above

The fourth step of the process is a holding step, which is carried out after the first cooling step, wherein the hot-rolled steel billet is maintained at a temperature of -570 ° C, preferably Md-570 ° C, for 10 to 300 seconds. In this holding step, the hot-rolled steel billet is maintained at a temperature above the temperature Ms, preferably Md. One purpose of the holding step is to equalize the temperature difference between the core part and the surface of the hot rolled steel billet. This reduces the probability of the hardening crack associated with the martensite change, which change in the process occurs in the fifth step, ° in the second cooling step.

g The fifth step of the process is the second cooling step, which is carried out after the g holding step, wherein the hot-rolled steel billet is cooled at a cooling rate of at least 0.5 ° C / s to below Mf to provide a medium carbon δ steel product.

The process can be used to produce a medium carbon steel product, such as tool steel, which has a part whose microstructure, by volume, is preferably greater than 90% martensitic, preferably greater than 95% martensitic.

In the process, the fifth step, the second cooling step, may be followed by the sixth step, i.e. the emission step. In such an emission step, the hot rolled medium carbon steel product is discharged. This results in an emission-articular microstructure. The release also reduces the likelihood of cracking a medium carbon steel product when using a medium carbon steel product.

All the steps of the process, the hot rolling step, the first cooling step, the holding step and the second cooling step, and any discharge step can be carried out in a hot rolling line.

The invention also relates to a medium carbon steel product.

The composition of the medium carbon steel product is selected such that the bainite change, the perlite change or the ferrite change does not substantially commence prior to the martensite conversion during the production of the medium carbon steel product using, for example, the method defined in independent claim 1.

The invention is useful because it provides a solution for the production of medium carbon steel products without hardening cracks, preferably for tool steels, by hot rolling in a hot rolling line, which is a cost effective process compared to prior art methods.

List of figures

The invention will now be described in more detail with reference to the figures, in which Fig. 1 shows part of the thermal cycle of the first embodiment of the method, Fig. 2 shows part of the thermal cycle of the second embodiment of the method, cyclic, Fig. 5 shows part of the thermal cycle g> of the fifth embodiment of the method, K Fig. 6 shows part of the thermal cycle o of the sixth embodiment of the method.

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DETAILED DESCRIPTION OF THE INVENTION

First, the method and various embodiments of the method for producing a medium carbon steel product from a steel blank containing Fe, unavoidable impurities and residual contents will be described in more detail.

The process comprises the step of providing 0.3% to 0.7% carbon, C, by weight of a steel blank.

The method comprises a hot rolling step for hot rolling a steel blank at a temperature of 800 to 1250 ° C to obtain a hot rolled steel blank.

The method comprises a first cooling step after the hot rolling step, wherein the hot rolled steel billet is cooled, preferably quenched, at a cooling rate corresponding to at least a critical cooling rate (CCR) to a temperature in the range Md-570 ° C.

The process comprises a holding step, which is carried out after the first cooling step, wherein the hot-rolled steel billet is maintained at a temperature in the range of Ms to 570 ° C, preferably in the range of Md to 570 ° C for 10 to 300 seconds.

The method comprises a second cooling step, which is performed after the holding step, wherein the hot-rolled steel billet is cooled at least at a cooling rate of 0.5 ° C / s to a temperature below Mf to provide a medium carbon steel product.

Preferably, but not necessarily, the step of providing the steel billet includes providing iron, Fe, and the necessary impurities and residues, and said carbon content, C, co, as a percentage by weight, of a steel billet containing: 0.7%, co manganese Mn 0.2 - 2.0%, preferably 0.4 - 1.4%, | chromium Cr 0.5 to 3.0%, preferably 1.0 to 1.8%, σ> vanadium V less than 1.0%, preferably less than 0.3%, O) to nickel Ni 1.0 to 6.0%, preferably 1.5 to 3.0%.

o Molybdenum Mo less than 1.0%. preferably 0.2 to 0.8%, wherein C + Ni + Cr + Mo, expressed as a percentage by mass, is 2.8 to 5.5%. More preferably, as a percentage by mass, C + Si + Mn + Cr + Ni + Mo + V is from 3.5 to 6.0%.

5

The criteria for the upper and lower limits of the necessary and optional components of the steel blank are as follows:

The steel blank contains 0.3 to 0.7% by weight of carbon, the lower limit of C is set at 0.3% to avoid the formation of bainite at a reasonable alloying level and further to achieve the desired hardness properties. The upper limit for C is set at 0.7% because too high a concentration of C reduces the impact toughness, which is disadvantageous in tool steels.

The steel blank may contain 0.05 to 2.0%, preferably 0.10 to 0.7% silicon, Si, expressed as a percentage by mass. Si improves the hardening without significantly affecting the weldability and should be doped at least 0.05%, preferably 0.10%. It is also usually needed for Ca inclusions treatment. The upper limit is set at 2.0%, preferably 0.7%, otherwise the surface quality may be impaired.

The steel billet may contain 0.2 to 2.0%, preferably 0.4 to 1.4% manganese, Mn, expressed as a percentage by mass. Mn improves the hardening, but must be less than 2.0%, preferably less than 1.4%, most preferably less than 1.0%, to avoid the filtration of Mn and C during the continuous casting process of medium carbon steel.

The steel blank may contain 0.5 to 3.0%, preferably 1.0 to 1.8%, by weight, of chromium, Cr. Cr improves the hardening and also delays the formation of bainite, thus shifting the bainite formation limit to the right in the CCT chart (continuous cooling change chart) and allowing a hold step without unwanted bainite.

The steel billet may contain less than 1.0%, preferably less than 0.3% vanadium, V, Vanadium can increase the hardening and VC can improve the abrasion resistance of the co.

The steel blank may contain from 1.0 to 6.0%, preferably from 1.5 to 3.0% nickel, Ni, by weight. Nickel is a useful dopant because it also delays o bainite formation, thus shifting the bainite formation limit in the CCT chart | to the right (Continuous Cooling Transformation) and allows for a hold step without the desired bainite βßο. In addition, nickel increases hardening and has a positive effect

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impact strength properties, which may be o important for tool steels. Potential emission treatment is avoided by doping high nickel contents (1.5 - 3.0%) due to the reduction in nickel cracking tendency after quenching.

6

The steel blank may contain less than 1.0%, preferably 0.2-0.8% molybdenum, Mo, expressed as a percentage by weight. Mo can be used especially when releasing a steel product to avoid emission brittleness or when the target is a higher hardness after release. Hot rolled steel can therefore be released at higher temperatures.

In one embodiment, the lower limit for mass of C + Ni + Cr + Mo is set at 2.8% and its upper limit at mass is set at 5.5%. Within this range, such a combination of compositions provides a steel which is quenchable immediately after the hot rolling process and maintained for a sufficiently long time at a temperature corresponding to a temperature of Ms-570 ° C, preferably Md-570 ° C, without undesirable microstructure of ferrite, perlite or bainite. In other words, this preferred composition combination forms an opening or at least a space above the bainite nipple where the austenite cannot be converted into unwanted ferrite, perlite or bainite in the microstructure.

In another embodiment, C + Si + Mn + Cr + Ni + Mo + V is set to a lower limit of 3.5% by weight and an upper limit of 6.0% by weight. Within this range, such a combination of compositions more preferably provides a steel which is capable of being quenched immediately after the hot rolling process and maintained for a sufficiently long time at a temperature corresponding to Ms-570 ° C, preferably Md-570 ° C, without undesirable ferrite, perlite or bainite. In other words, this most advantageous composition combination forms an opening, or at least a gap, above the bainite nipple and below the perlite nipple, where α austenite cannot be converted into unwanted ferrite, perlite or bainite in the microstructure.

i Y The steel billet may contain less than 0.02% titanium, co Ti%, expressed as a percentage by mass. Titanium may be doped in a heat treatment such as incineration or g) to avoid coarse-grained microstructure caused by welding or during reheating (g) prior to heat treatment.

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Lo The steel billet may contain, by mass, less than 0.03% niobium, o Nb. Niobium is not intentionally doped in this steel product because high carbon content with Nb can reduce impact toughness.

The steel billet may contain less than 0.1% tungsten, by weight, in W.

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Advantageously, the use of tungsten is avoided because it is very expensive.

The steel billet may contain less than 1.0% copper, Cu, expressed as a percentage by mass. Copper may slightly increase the hardening.

The steel billet may contain less than 0.0005% boron, expressed as a percentage by mass, of boron. Boron is not intentionally mixed with this steel product because the hardness is sufficiently high in the absence of boron.

The steel billet may contain 0.02 to 0.15% by weight, aluminum, Al, by weight. Aluminum is necessary to achieve a fully sealed steel and can also increase the hardening.

The steel blank may also contain other alloying materials not mentioned in this specification.

Preferably, the first cooling step is carried out immediately, but not necessarily, immediately after the hot rolling step so that the temperature of the hot rolled steel blank at the start of the first cooling step is in the range 700-1000 ° C.

Hot-rolled steel billets are preferably, but not necessarily, cooled at a rate of 5-100 ° C / s, preferably 10-50 ° C / s, during the first cooling step, thus being quenched.

In one embodiment of the process, the hot-rolled steel billet is cooled to a temperature in the range of 421-570 ° C in the first cooling step. In this embodiment of the process, the hot-rolled steel billet is maintained in a holding step at a temperature in the range of 421-570 ° C. In this embodiment of the method, the second cooling step is performed immediately after the holding step. In this embodiment of the process, the temperature of the hot-rolled steel billet at the beginning of the second cooling step is in the range 421-570 ° C. In this embodiment of the process co, the hot-rolled steel billet is cooled in a second cooling step at a rate of 5-100 ° C / s, preferably at a rate of 10-50 ° C / s.

In another embodiment of the process, the hot-rolled steel billet n is cooled in a first cooling step to a temperature in the range Ms - 421 ° C | temperature. In this embodiment of the method, the hot-rolled steel billet g> is maintained in the holding step at a temperature in the range of Ms to 421 ° C. The method

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in this embodiment, the temperature of the hot-rolled steel billet at the beginning of the second cooling step is in the temperature range Ms to 421 ° C. In this embodiment of the process, the hot-rolled steel billet is cooled in a second cooling step by air cooling.

8

The method may include a smoothing step for smoothing a hot-rolled steel billet, wherein the smoothing step is performed in connection with the holding step after the first cooling step and before the second cooling step. The smoothing is preferably carried out at this stage of the process when the hot-rolled steel billet is still relatively soft and does not yet have a martensitic microstructure. Reference is made in this respect to Figure 6, which shows a portion of the temperature variation over time of an embodiment of the method including such a smoothing step in the holding step.

The process may include an emission step which is carried out after the second cooling step, in which the hot-rolled steel billet is discharged at a temperature above Mf, preferably between Mf and Ms, e.g. 150-250 ° C. Hot rolled steel billets can be discharged at a temperature of Ms - Md for 20 to 1500 minutes. In this regard, reference is made to Figure 4, which shows a part of the thermal cycle of an embodiment of the method including such an emission step. Steel produced using such a release step has good hardness properties, which is advantageous for good abrasion resistance.

Alternatively, the process may include an emission step after a second cooling step, in which the hot-rolled steel billet is discharged at a temperature above Md, e.g. 400-450 ° C or 600-700 ° C. The hot-rolled steel billet can be cast at temperatures above Md, e.g. 400 to 450 ° C or 600 to 700 ° C for 2 to 400 minutes. Reference is made in this respect to Figure 2, which shows a portion of the temperature variation over time of an embodiment of the method, including a discharge step at a discharge temperature of 600 to 700 ° C. Reference is also made in this respect to Fig. 3, whereby ™ shows a portion of the temperature variation over time of one embodiment of the method, including an outlet step having an outlet temperature of 400-450 ° C.

w The discharge temperature in the range of 600 ° C to 700 ° C is particularly suitable for hot-rolled I medium carbon steels for products for which

g> surface tempering, for example by induction heating. In the range 600-700 ° C

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v? Exhaust temperature improves stretchability and impact strength. If the discharge temperature o exceeds 650 ° C, machinability is improved and internal stress and deformation are reduced, which is advantageous for machining a hot rolled medium carbon steel product.

9

The discharge temperature in the range of 400 ° C to 450 ° C is particularly suitable for hot rolled medium carbon steel products which are subsequently subjected to nitration or gas nitration.

If the process includes an after-cooling step, the discharge step is preferably, but not necessarily, after the second cooling step before the temperature of the hot-rolled steel billet during the second cooling step has dropped below 100 ° C. This reduces the likelihood of hardening cracking compared to allowing the hot-rolled steel billet to cool to room temperature, i.e., about 20 ° C. This also reduces the amount of energy required for production.

Six embodiments of the method will now be described with reference to Figures 1-6.

Figure 1 shows part of the temperature variation of the first embodiment of the method over time. In the embodiment shown in Figure 1, the steel billet is first hot-rolled at a temperature of 800 to 1250 ° C to provide a hot-rolled billet. Immediately after the hot rolling step, the first cooling step is performed such that the temperature of the hot rolled steel blank at the beginning of the first cooling step is in the range of 700-1000 ° C. In the first cooling step, the hot-rolled steel billet is cooled at a rate of at least 5 ° C / sec to a temperature in the range of 420-570 ° C. The first cooling step is followed by a holding step in which the hot-rolled steel billet is held at a temperature of 420-570 ° C for 10-300 seconds. Immediately after the holding step, a second cooling step is performed in which the hot-rolled steel billet is cooled to at least 5 ° C / sec below Mf to provide a medium carbon steel product.

Fig. 2 shows part of the thermal cycle of another embodiment of the method.

The embodiment shown in Fig. 2 corresponds to the embodiment shown in Fig. 1 with the difference that after the second cooling step, an emission step is performed. In Figure 2 this discharge step is carried out before the temperature of the hot rolled steel billet g drops below 100 ° C during the second cooling step. In Figure 2, the release temperature is between 600 and 700 ° C.

Figure 3 shows part of the thermal cycle of the third embodiment of the method. The embodiment shown in Figure 3 corresponds to the embodiment shown in Figure 2 with the difference that the outlet temperature is between 420 and 570 ° C.

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Figure 4 shows part of the thermal cycle of a fourth embodiment of the method. The embodiment shown in Fig. 3 corresponds to the embodiment shown in Fig. 2 with the difference that the discharge temperature is between Mf and Ms, e.g. 150 to 250 ° C.

Figure 5 shows part of the thermal cycle of the fifth embodiment of the method. In the embodiment shown in Fig. 5, the steel billet is first hot-rolled at a temperature in the range of 800 to 1250 ° C to provide a hot-rolled billet. Immediately after the hot rolling step, the first cooling step is performed such that the temperature of the hot rolled steel blank at the beginning of the first cooling step is in the range of 700-1000 ° C. In the first cooling step, the hot-rolled steel billet is cooled at a rate of at least 5 ° C / sec to a temperature in the range of Ms to 420 ° C. The first cooling step is followed by a holding step in which the hot-rolled steel billet is held at a temperature of Ms-420 ° C for 10 to 300 seconds. After the holding step, a second cooling step is performed in which the hot-rolled steel billet is cooled, for example in air, at least at a rate of 0.1 ° C / sec to 100 ° C to provide a medium carbon steel product.

Figure 6 shows part of the thermal cycle of a sixth embodiment of the method. The embodiment shown in Fig. 6 corresponds to the embodiment shown in Fig. 1, except that a release step is performed in connection with the holding step.

The following describes a hot-rolled medium carbon steel product containing iron, Fe, and inevitable impurities and residues.

The hot-rolled medium carbon steel product containing Fe and inevitable impurities and residues also contains, by weight, co: ° C C 0.3-0.7%, Si Si 0.05-2.0%, preferably 0.10-0.7%, m manganese Mn 0.2-1.5%, preferably 0.4 - 1.0% | chromium Cr 0.5-3.0%, preferably 1.0-1.8%, σ> vanadium V less than 1.0%, preferably less than 0.3%, O) nickel Ni 1.0-6.0%, preferably 1.5-3.0%.

molybdenum Mo less than 1.0%, preferably 0.2-0.8%, wherein C + Ni + Cr + Mo expressed as a percentage by weight is 2.8-5.5%.

In another 11 embodiments of the hot rolled medium carbon steel product, C + Si + Μη + Cr + Ni + Mo + V is expressed in mass percentages from 3.5 to 6.0%.

In addition, the hot-rolled medium carbon steel product containing Fe and inevitable impurities and residues may contain boron, B, less than 0.0005%, expressed as a percentage by mass.

In addition, the hot-rolled medium carbon steel product containing Fe and inevitable impurities and residues may contain titanium, Ti, less than 0.02%, expressed as a percentage by mass.

In addition, the hot-rolled medium carbon steel product containing Fe and inevitable impurities and residues may contain less than 0.03% niobium, Nb, expressed as a percentage by mass.

In addition, the hot-rolled medium carbon steel product containing Fe and inevitable impurities and residues may contain aluminum, Al, 0.02 to 0.15% by weight.

In addition, the hot-rolled medium carbon steel product containing Fe and the inevitable impurities and residues may contain, by weight, tungsten, W, less than 0.1%.

In addition, the hot-rolled medium carbon steel product containing Fe and unavoidable impurities and residues may contain less than 1.0% copper, Cu, expressed as a percentage by mass.

In addition, the hot-rolled medium carbon steel product containing Fe and unavoidable impurities and residues may also contain other alloys not mentioned in this specification.

The effect of the components is explained in conjunction with the detailed description co of the method.

The table below shows exemplary compositions.

ό 0

C/O

1 I - ^^ - £ Example 1 Example 2 g> C 0.4 0.4 to Ci 0.25 0.25 δ Μη 0.6 0.6 C \ J ---

Cr_JL5_0.65

Ni 1.5 2.55 12

Mo 0.3_10.55_ AI 0.04 0.04

The composition is designed to cause an opening, or at least a gap, above the bainite nipple and below the perlite nipple where the austenite cannot be converted into unwanted ferrite, perlite or bainite in the microstructure. This enables cost-effective production of hot rolled medium carbon steel products using quenching.

Part of the hot rolled medium carbon steel product preferably, but not necessarily, has a microstructure containing more than 90%, preferably more than 95% by volume of martensite.

Part of the hot rolled medium carbon steel product may also have a microstructure containing more than 90%, preferably greater than 95% by volume of martensite released.

When quenched, the hot rolled medium carbon steel product preferably has a hardness of 500 to 800 HB measured at 2 mm, preferably 5 mm from the surface of the medium carbon steel product. Further release may result in a hardness reduction of 300 to 750 HB depending on the release conditions and the composition of the steel.

In particular, when the hot rolled medium carbon steel product is released at temperatures of at least 400 ° C, the steel product may further have a tensile strength Rp0.2 of more than 800 MPa, a yield strength of 1000-1300 MPa, elongation A5> 10% and Charpy V (20 ° C)> 45 J.

Preferably, the steel product is a sheet steel sheet with a thickness of from 5 to 80 mm, preferably from 6 to 60 mm, manufactured by flat-roll milling.

In one embodiment, the hot-rolled medium carbon steel product is manufactured by the process described in claims 1 to 25 (p. 24).

It will be obvious to one skilled in the art that, with the advancement of technology, the basic idea of the invention can be implemented in various ways. The invention and its embodiments are therefore not limited to the above examples, but may not vary within the scope of the claims.

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Claims (39)

1. A process for producing a medium carbonaceous ground product of a ground ticket, characterized in that the process comprises a step of obtaining a ground ticket which contains, by weight, 0.3-0.7% C, iron Fe and inevitable impurities and residual contents, a hot rolling step for hot rolling the set ticket at a temperature of 800 - 1250 ° C to provide a hot rolled set ticket, a first cooling step which is performed after the hot rolling step and in which the hot rolled set ticket is cooled at least at such a cooling rate corresponding to the critical cooling rate ( CCR), to a temperature in the range of Ms - 570 ° C, advantageously to a temperature in the range of Md - 570 ° C, a pouring step which is carried out after the first cooling step and for which for a period of 10 - 300 seconds it is poured. hot-rolled frame at a temperature in the range of Ms - 570 ° C, advantageously at a temperature in the range of MD - 570 ° C, and a second cooling step, which is carried out after the pouring step and in which the hot-rolled frame image is cooled at a rate of at least 0.5 ° C / s to a temperature lower than the temperature Mf to obtain the medium carbonaceous frame product. 2. A method according to claim 1, characterized in that the step of obtaining an adjusting ticket entails obtaining an adjusting ticket, which in co weight percent contains at least the following ° Si 0.05 - 2.0%, in ° Mn 0.2 - 2 , 0%, m Cr 0.5 - 3.0%, | V less than 1.0%, σ> Ni 1.0 - 6.0%, O) LO m Mo less than 1.0% o where in weight percent C + Ni + Cr + Mo is 2.8 - 5.5 %. 21 Method according to claim 2, characterized in that an adjusting ticket is provided which contains in weight percent 0.10 - 0.7% silicon Si. 4. A method according to claims 2-3, characterized in that an actuarial ticket is provided which contains in weight percent 0.4 - 1.4%, advantageously 0.4 - 1.0%, manganese Mn. Process according to any of claims 2-4, characterized in that an actuarial ticket is provided which contains in weight percent 1.0 - 1.8% chromium Cr. Method according to any of claims 2-5, characterized in that an actuarial ticket is provided which contains, by weight, less than 0.3% vanadium V. Process according to any one of claims 2-6, characterized in that an actuarial ticket is provided which contains, in weight percent, 1.5 - 3.0% nickel Ni. Method according to any one of claims 2-7, characterized in that an adjusting ticket is provided which contains in weight percent 0.2 - 0.8% molybdenum Mo. Method according to any of claims 2-8, characterized in that an adjusting ticket is provided which contains in weight percent 3.5 - 6.0% C + Si + Mn + Cr + Ni + Mo + V. 10. A method according to any of claims 1 to 9, characterized in that the step of co to obtain an adjusting ticket entails obtaining an adjusting ticket which, in% by weight, further contains less than 0.02% titanium Ti. i o co Method according to any of claims 1-10, characterized in that the step | to obtain an actuarial ticket means obtaining an actuarial ticket which, in σ> weight percent, further contains less than 0.03% niob Nb. m m o Method according to any of claims 1-11, characterized in that the step of obtaining an adjusting ticket means obtaining an adjusting ticket which, in weight percent, further contains less than 1.0% copper Cu. 22 Method according to any of claims 1-12, characterized in that the step of obtaining an actuarial ticket means obtaining an actuarial ticket which further contains less than 0.0005% boron B. by weight. A method according to any of claims 1-13, characterized in that the step of obtaining an adjusting ticket entails obtaining an adjusting ticket which contains in weight percent 0.02 - 0.15% aluminum AI. Method according to any of claims 1-14, characterized in that the first cooling step is carried out immediately after the hot rolling step, and also that the temperature of the hot rolled billet at the beginning of the first cooling stage is within the range 700-1000 ° C. Method according to any of claims 1-15, characterized in that in the first cooling step the hot-rolled frame ticket is cooled at a rate of 5-100 ° C / s, advantageously at a rate of 10 - 50 ° C / s. Method according to any one of claims 1-16, characterized in that in the first cooling step the hot-rolled adjustable ticket is cooled to a temperature within the range 421-570 ° C, by pouring the hot-rolled adjustable ticket at a temperature within the range. 421-570 ° C by performing the second cooling step immediately after the pouring step, co of the temperature of the hot rolled billet at the beginning of the second ° cooling step is within the range 421-570 ° C, and in Y by the second cooling step cools the hot-rolled frame ticket at a rate of 5 - 100 ° C / s, advantageously at a rate of 10 - 50 ° C / s. CC CL g 18. A method according to any of claims 1-17, characterized in that in the first cooling step the hot-rolled adjusting ticket is cooled to an o temperature within the range of Ms - 421 ° C, by pouring the hot-rolled adjusting ticket at a temperature in the pouring step. in the range Ms - 421 ° C, 23 because the temperature of the hot rolled billet at the beginning of the second cooling step is within the range Ms - 421 ° C, and of the second cooling step the hot rolled billet is cooled by air cooling. Method according to any of claims 1-18, characterized in that it contains a leveling step for smoothing the hot-rolled frame ticket, whereby the leveling step is carried out in connection with the pouring step after the first cooling step and before the second cooling step. Method according to any of claims 1-19, characterized in that it contains a curing step which is carried out after the second cooling step, wherein the curing step cures the hot-rolled adjustable image at a temperature which exceeds the temperature Mf, advantageously at a temperature which between the temperature Mf and the temperature Ms, e.g. 150 - 250 ° C. Method according to claim 20, characterized in that the hot-rolled frame image is cured for a period of 20 - 1500 minutes. Method according to any of claims 1-21, characterized in that it contains a curing step which is carried out after the second cooling step, wherein the curing step cures the hot-rolled adjustable image at a temperature exceeding the temperature Md, for example at a temperature of 400 - 450 ° C or 600 - 700 ° C. CO A method according to claim 22, characterized in that it is cured? hot-rolled frame ticket for a time of 2 - 400 minutes. i o CO Process according to any of claims 20-23, characterized in that the curing step is carried out after the second cooling step before the temperature of the hot rolled K adjusting plate has dropped to a temperature below 100 ° C. δ c \ j 25. A hot rolled medium carbon steel product containing iron Fe, unavoidable impurities and residual contents and prepared by a method according to any of claims 24 to 24, characterized in that it contains at least the following by weight: C 0.3 - 0.7 %, Si 0.05 - 2.0%, Mn 0.2 - 2.0%, Cr 0.5 - 3.0%, V less than 1.0%, Ni 1.0 - 6.0%, Mo less than 1.0%. whereby in weight percent C + Ni + Cr + Mo is 2.8 - 5.5%. 26. A hot-rolled medium carbon steel frame product according to claim 25, characterized in that an ground ticket is provided, which contains, by weight, 0.10 - 0.7% silicon Si. 27. A hot-rolled medium carbon steel product according to claim 25 or 26, characterized in that a steel ticket is provided, which in weight percent contains 0.4 - 1.4%, advantageously 0.4 - 1.0%, manganese Mn. 28. Hot-rolled medium carbon steel product according to any one of claims 25 - 27, characterized in that a steel ticket is provided, which in weight percent contains 1.0 - 1.8% chromium Cr. 29. A hot-rolled medium carbon steel product according to any one of claims 25 to 28, characterized in that a steel ticket is provided which contains, by weight, less than co 0.3% vanadium V. δ c 30. A hot-rolled medium carbon steel product according to any one of claims 25 - 29, co characterized in that a steel ticket is provided, which in weight percent contains 1.5 - | 3.0% nickel Ni. CD O) LO 31. A hot-rolled medium carbon steel product according to any one of claims 25-30, characterized in that an steel ticket is provided which contains in weight percent 0.2 - 0.8% molybdenum Mo. 25 32. A hot-rolled medium carbon steel product according to any one of claims 25 to 31, characterized in that a steel ticket is provided, which in weight percent contains 3.5 - 6.0% C + Si + Mn + Cr + Ni + Mo + V. 33. A hot rolled medium carbon steel product according to any one of claims 25 to 32, characterized in that a steel ticket is provided, which in weight percent further contains less than 0.0005% boron B. 34. A hot-rolled medium carbon steel product according to any one of claims 25 to 33, characterized in that a steel billet is provided, which in weight percent further contains less than 0.02% titanium Ti. 35. A hot-rolled medium carbon steel product according to any one of claims 25 to 27, characterized in that a steel ticket is provided, which in weight percent further contains less than 0.03% niob Nb. 36. A hot-rolled medium carbon steel product according to any one of claims 25 to 35, characterized in that a steel billet is provided, which contains, by weight, 0.02-0.15% aluminum AI. 37. A hot rolled medium carbon steel product according to any one of claims 25 to 36, characterized in that a steel ticket is produced which contains, by weight, less than 1.0% copper Cu. co 38. Hot rolled medium carbon steel product according to any one of claims 25 - 37, characterized in that part of the hot rolled steel product with medium high carbon content has a microstructure that contains more than 90%, advantageously more than 95%, martensite. X tr CL g) 39. Hot rolled medium carbonaceous grounding product according to any of claims 25 to 37, characterized in that part of the hot rolled medium carbonaceous grounding product has a microstructure which contains more than 90%, advantageously more than 95%, cured martensite.