EP1918407B1 - Iron-cobalt based soft magnetic alloy and method for its manufacture - Google Patents

Abstract

The soft magnetic alloy contains cobalt (in weight%) (10-22), vanadium (0-4), chromium (1.5-5), manganese (1-2), molybdenum (0-1), silicon (0.5-1.5), aluminum (0.1-1), and remainder of iron. The soft magnetic alloy contains cobalt (in weight%) (10-22), vanadium (0-4), chromium (1.5-5), manganese (1-2), molybdenum (0-1), silicon (0.5-1.5), aluminum (0.1-1), and remainder of iron. The sum total of silicon and aluminum content is 0.6-2 weight%. The sum total of chromium, manganese, molybdenum, silicon, aluminum and vanadium content is 4-9 weight%. The soft magnetic alloy further contains nitrogen (200 ppm or less), carbon (400 ppm or less) and oxygen (100 ppm or less) as impurities. An independent claim is included for manufacture of soft magnetic alloy.

Description

The invention relates to a soft magnetic iron-cobalt-based alloy having a cobalt content of 10% by weight (wt .-%) to 22 wt .-%, and a method for producing the alloy and a method for producing semi-finished from this alloy , in particular of magnetic components for actuator systems.

Soft magnetic alloys based on iron-cobalt have a high saturation magnetization and can therefore be used to form high-force and / or small-volume electromagnetic actuator systems. A typical application of these alloys are solenoid valves, such as solenoid valves for fuel injection in internal combustion engines.

Soft magnetic alloys based on iron-cobalt with a cobalt content of 10 wt .-% to 22 wt .-% are for example from US 7,128,790 known. When using these alloys in fast-switching actuators, the switching frequency can be limited due to the resulting eddy currents. Further, improvements in the strength of the magnetic cores in continuous operation in high frequency actuator systems are desired.

Similar alloys are also in the documents DE 4444482 . EP 0715320 or JP-A-62093342 mentioned.

The object of the invention is therefore to provide an alloy which is better suited for use as a magnetic core in fast-switching actuators.

This is achieved according to the invention by the subject matter of the independent claims. Further advantageous developments emerge from the dependent claims.

According to the invention, a soft magnetic alloy consists of 10% by weight ≦ Co ≦ 22% by weight, 0% by weight ≦ V ≦ 4% by weight, 1.5% by weight ≦ Cr ≦ 5% by weight, 1 wt .-% ≤ Mn ≤ 2 wt .-%, 0 wt .-% ≤ Mo ≤ 1 wt .-%, 0.5 wt .-% ≤ Si ≤ 1.5 wt .-%, 0.1 wt .-% ≤ Al ≤ 1.0 wt .-%, balance iron and unavoidable impurities.

Preferably, the alloy has impurities such as a maximum of 200 ppm of nitrogen, a maximum of 400 ppm of carbon and a maximum of 100 ppm of oxygen.

The alloy according to the invention has a higher specific resistance compared with the binary Co-Fe alloy, which leads to a suppression of the eddy currents, with the lowest possible lowering of the saturation polarization. This is achieved by the alloying of the non-magnetic elements. Further, the alloy has higher strength due to the content of Al and Si. This alloy is suitable for use as a magnetic core of a fast-switching actuator system, such as a fuel injection valve of an internal combustion engine.

Cr and Mn show a strong resistance increase with a low saturation reduction. At the same time, the annealing temperature, which corresponds to the upper limit of the ferritic phase, is lowered. However, this is not desired because this leads to poorer soft magnetic properties.

Al, V and Si also increase the electrical resistance while raising the annealing temperature. Thus, an alloy with high resistance, high saturation and high annealing temperature and thus good soft magnetic properties can be specified.

Further, the alloy has higher strength due to the content of Al and Si. The alloy is cold-workable and ductile in the final annealed condition. The alloy can have an elongation A _L of> 2%, preferably A _L > 20%. The elongation A _L is measured during tensile tests. This alloy is suitable for use as a magnetic core of a fast-switching actuator system, such as a fuel injection valve of an internal combustion engine.

The requirements for a magnetically soft cobalt-iron-based alloy for an actuator system are contradictory. A higher cobalt content in the binary alloy leads to a higher saturation magnetization J _s of approximately 9 mT per 1 wt% Co (starting from 17 wt% Co) and thus allows a smaller overall volume and a higher system integration or higher actuator forces for the same size. At the same time, however, the cost of the alloy increases. As the Co content increases, the soft magnetic properties, such as permeability, deteriorate. Above a cobalt content of 22% by weight, the increase in saturation is reduced by further co-alloying.

The alloy should also have high electrical resistivity and good soft magnetic properties.

This alloy thus has a cobalt content of 10% by weight ≦ Co ≦ 22% by weight. A low cobalt content reduces the raw material cost of the alloy, making it suitable for high cost pressure applications, such as in the automotive industry. The maximum permeability is high within this range, which leads to cheaper lower drive currents when used as an actuator.

In other embodiments, the alloy has a cobalt content of 14 wt% ≤ Co ≤ 22 wt% and 14 wt% ≤ Co ≤ 20 wt%.

The soft magnetic alloy of the magnetic core has a content of chromium and manganese, which leads to a higher electrical resistivity p in the annealed state with little decrease in saturation. This higher resistivity allows smaller switching times for an actuator as eddy currents are reduced. At the same time, the alloy has a high saturation and a high permeability μ _max , so that good soft magnetic properties are maintained.

The elements Si and Al of the alloy provide improved strength of the alloy without significantly degrading the soft magnetic properties. By alloying Si and Al, the strength of the alloy can be significantly increased by solid solution hardening, without a significant deterioration of the soft magnetic properties.

The aluminum content and vanadium content according to the invention enables a higher annealing temperature, which leads to good soft magnetic properties of the coercive force H _c and the maximum permeability μ _max leads. High permeability is desired, as this leads to lower drive currents when using the alloy as a magnetic core or flux guide of an actuator.

In one embodiment, the alloy has a silicon content of 0.5% by weight ≦ Si ≦ 1.0% by weight.

The content of Mo has been kept low to prevent the formation of carbides, which may lead to deterioration of the magnetic properties.

In addition to Cr and Mn, a low molybdenum content is favorable, since this content of molybdenum is characterized by a good ratio of resistance increase to saturation decrease.

In one embodiment, the content of aluminum and silicon is from 0.6% by weight ≦ Al + Si ≦ 1.5% by weight, so that brittleness and processing problems that may occur with higher total contents of aluminum and silicon are avoided ,

In one embodiment, the content of the elements is chromium and manganese and molybdenum and aluminum and silicon and vanadium 4.0 wt% ≤ (Cr + Mn + Mo + Al + Si + V) ≤ 9.0 wt%. This alloy has an even higher resistivity compared to the binary CoFe alloy, which leads to a suppression of the eddy currents, at the same time the saturation polarization is lowered as little as possible and the coercive field strength H _{c is} even less increased.

The content of chromium and manganese and molybdenum and aluminum and silicon and vanadium in one embodiment is 6.0% by weight ≦ Cr + Mn + Mo + Al + Si + V ≦ 9.0% by weight.

In further embodiments, the soft magnetic alloy consists of 10 wt% ≤ Co ≤ 22 wt%, 0 wt% ≤ V ≤ 1 wt%, 1.5 wt% ≤ Cr ≤ 3 wt. %, 1 wt% ≤ Mn ≤ 2 wt%, 0 wt% ≤ Mo ≤ 1 wt%, 0.5 wt% ≤ Si ≤ 1.5 wt%, 0 , 1 wt .-% ≤ Al ≤ 1.0 wt .-%, balance iron and unavoidable impurities. It can have a content of aluminum and silicon of 0.6% by weight ≦ Al + Si ≦ 1.5% by weight and / or a content of chromium and manganese and molybdenum and aluminum and silicon of 4.5% by weight. % ≦ Cr + Mn + Mo + Al + Si ≦ 6.0 wt%.

In one embodiment, the alloy contains V = 0 wt%, 1.6 wt% ≤ Cr ≤ 2.5 wt%, 1.25 wt% ≤ Mn ≤ 1.5 wt%, 0 wt% ≤ Mo ≤ 0.02 wt%, 0.6 wt% ≤ Si ≤ 0.9 wt% and 0.2 wt% ≤ Al ≤ 0.7 wt% %.

In one embodiment, the alloy contains 0 wt% ≤ V ≤ 2.0 wt%, 1.6 wt% ≤ Cr ≤ 2.5 wt%, 1.25 wt% ≤ Mn ≤ 1.5 wt%, 0 wt% ≤ Mo ≤ 0.02 wt%, 0.6 wt% ≤ Si ≤ 0.9 wt%, and 0.2 wt% ≤ Al ≦ 0.7% by weight.

In one embodiment, the alloy contains 0 wt% ≤ V ≤ 0.01 wt%, 2.3 wt% ≤ Cr ≤ 3.0 wt%, 1.25 wt% ≤ Mn ≤ 1.5 wt%, 0.75 wt% ≤ Mo ≤ 1 wt%, 0.6 wt% ≤ Si ≤ 0.9 wt% and 0.1 wt% ≤ Al ≦ 0.2 wt .-%.

In one embodiment, the alloy contains 0.75 wt% ≤ V ≤ 2.75 wt%, 2.3 wt% ≤ Cr ≤ 3.5 wt%, 1.25 wt% ≤ Mn ≤ 1.5 wt%, 0 wt% ≤ Mo ≤ 0.01 wt%, 0.6 wt% ≤ Si ≤ 0.9 wt% and 0.2 wt% % ≦ Al ≦ 1.0 wt%.

These three alloys have a preferred combination of high electrical resistance, high saturation, and low coercivity.

Alloys with the abovementioned compositions have a specific electrical resistance ρ> 0.50 μΩm or ρ> 0.55 μΩm or ρ> 0.60 μΩm or ρ> 0.65 μΩm. This value provides for an alloy, so that when used as a magnetic core of an actuator system lower eddy currents. This allows the use of the alloy in actuator systems with higher switching times.

The proportion of the elements aluminum and silicon in the alloy _according to the invention leads to an alloy with a yield strength of R _p0.2 > 340 MPa. This higher strength of the alloy can extend the life of the alloy when used as a magnetic core of an actuator system. This is attractive in using the alloy in high frequency actuator systems, such as fuel injection valves in internal combustion engines.

The alloy according to the invention has good soft magnetic properties as well as good strength and high electrical resistivity. In further embodiments, the alloy has a saturation of J (400A / cm)> 2.00 T or> 1.90 T, and / or a coercive force H _c <3.5 A / cm or H _c <2.0 A / cm or and / or H _c <1.0 A / cm has a maximum permeability μ _max > 1000 or μ _max > 2000.

The inventive content of chromium and manganese and molybdenum and aluminum and silicon and vanadium is between 4.0 wt .-% and 9.0 wt .-%. This higher content allows to provide an alloy that has a higher electrical resistance of ρ> 0.6 μΩm and a low coercive force H _c <2.0 A / cm. This combination of properties is particularly suitable for use with fast switching actuators.

The invention further provides a soft magnetic core or flux guide for an electromagnetic actuator made of an alloy according to one of the preceding embodiments. This soft magnetic core is in various embodiments a soft magnetic core for a solenoid valve of an internal combustion engine, a soft magnetic core for a fuel injection valve of an internal combustion engine, a soft magnetic core for a direct fuel injection valve of a gasoline engine or a diesel engine, or a soft magnetic component for electromagnetic valve timing such as intake and exhaust valves.

The different actuator systems, such as solenoid valves and fuel injection valves have different requirements for strength and magnetic properties. These requirements can be met by selecting an alloy having a composition within the ranges described above.

The invention also provides a fuel injection valve of an internal combustion engine with a soft magnetic alloy component according to one of the preceding embodiments. In other embodiments, the fuel injector is a direct fuel injection valve of a gasoline engine and a direct fuel injection valve of a diesel engine.

In further embodiments, the invention provides an electromagnetic actuator return member and a soft magnetic rotor and a soft magnetic stator for an electric motor and a soft magnetic component for electromagnetic valve timing on an intake valve or exhaust valve used in an engine compartment of, for example, a motor vehicle, of an alloy according to one of the preceding embodiments.

The invention also provides a process for the production of semi-finished products from a cobalt-iron alloy, in which workpieces made of a soft magnetic alloy are first produced by melting and hot working, which consist of 10% by weight ≦ Co ≦ 22% by weight, 0 wt% ≤ V ≤ 4 wt%, 1.5 wt% ≤ Cr ≤ 5 wt%, 1 wt% ≤ Mn ≤ 2 wt%, 0 wt% ≤ Mo ≦ 1 wt .-%, 0.5 wt .-% ≤ Si ≤ 1.5 wt .-%, 0.1 wt .-% ≤ Al ≤ 1.0 wt .-%, balance iron and unavoidable impurities ,

The alloy of the workpieces can also have a composition according to one of the preceding embodiments.

The alloy can be melted by various methods. In theory, all common techniques are possible, such as air melting or VIM (vacuum induction melting). For this, e.g. the arc furnace or inductive techniques are used. Treatment with VOD (Vacuum Oxygen Decarburization) or AOD (Argon Oxygen Decarburization) or ESU (Electric Slag Remelting) improves the quality of the product.

For the production of the alloy, the VIM method is preferred, since thus the contents of the alloying elements more exactly can be set and non-metallic inclusions in the solidified alloy can be better avoided.

The melting process is followed by a different series of process steps, depending on the semifinished product to be produced.

If tapes are to be produced, from which parts are later punched, the ingot resulting from the melting process is converted by pre-blocking into a slab. Preblocking is understood to mean the forming of the ingot into a rectangular section slab by a hot rolling operation at a temperature of, for example, 1250 ° C. After blooming, the scale formed on the surface of the slab is removed by grinding. The grinding is followed by another hot rolling process by which the slab is formed into a strip at a temperature of, for example, 1250 ° C. Subsequently, the impurities formed on the surface of the belt during hot rolling are removed by grinding or pickling, and the strip is cold-worked to the final thickness, which may be in the range of 0.1 mm to 2 mm. Finally, the tape is subjected to a final annealing. During final annealing, the lattice defects resulting from the forming processes heal and crystalline grains are formed in the microstructure.

Similarly, the manufacturing process is when turning parts are produced. Again, billets are made by pre-blocking the ingot with a square cross-section. The so-called pre-blocking takes place at a temperature of for example 1250 ° C. Subsequently, the scale formed during pre-blocking is removed by grinding. This is followed by another hot rolling process, through which the billets in bars or wires up to a diameter of, for example 13 mm to be formed. By straightening and peeling, on the one hand, distortions of the material are corrected and, on the other hand, the impurities forming on the surface during the hot rolling process are removed. Finally, here too, the material is subjected to a final annealing.

The final annealing can be carried out in a temperature range of 700 ° C to 1100 ° C. In one embodiment, the final annealing is carried out in the temperature range from 750 ° C to 850 ° C. The final annealing can be carried out under inert gas, hydrogen or vacuum.

The conditions such as temperature and duration of the final annealing can be selected so that after the final annealing the alloy has tensile strain parameters of elongation at break A _L > 2% or A _L > 20%.

In another embodiment, the alloy is cold worked prior to final annealing.

Figur 1

zeigt ein Magnetventil mit einem Magnetkern aus einer erfindungemäßen weichmagnetischen Legierung,

Figur 2

zeigt ein Ablaufdiagramm des Herstellverfahrens für Halbzeug aus der Legierung gemäß der Erfindung, und

Figur 3

zeigt die Koerzitivfeldstärke H_c in Abhängigkeit von der Glühtemperatur für verschiedene erfindungsgemäße weichmagnetische Legierungen.

Figur 4

zeigt die Koerzitivfeldstärke H_c in Abhängigkeit von der Glühtemperatur für weitere erfindungsgemäße weichmagnetische Legierungen.

Figur 1 zeigt ein elektromagnetisches Aktorsystem 20 mit einem Magnetkern 21 aus einer erfindungsgemäßen weichmagnetischen Legierung, die in einer ersten Ausführungsform aus 18,3 Gew.-% Co, 2,62 Gew.-% Cr, 1,37 Gew.-% Mn, 0,85 Gew.-% Si, 0,01 Gew.-% Mo, 0,21 Gew.-% Al, Rest Eisen besteht. In einem weiteren nicht gezeigten Ausführungsbeispiel ist ein Rückschluss aus dieser Legierung angegeben.The invention will be explained in more detail with reference to the drawings.

FIG. 1

shows a solenoid valve with a magnetic core made of a soft magnetic alloy according to the invention,

FIG. 2

shows a flow chart of the manufacturing process for semi-finished alloy of the invention, and

FIG. 3

shows the coercive force H _c as a function of the annealing temperature for various soft magnetic alloys according to the invention.

FIG. 4

shows the coercive force H _c as a function of the annealing temperature for further soft magnetic alloys according to the invention.

FIG. 1 shows an electromagnetic actuator system 20 with a magnetic core 21 of a soft magnetic alloy according to the invention, which in a first embodiment of 18.3 wt .-% Co, 2.62 wt .-% Cr, 1.37 wt .-% Mn, 0, 85 wt .-% Si, 0.01 wt .-% Mo, 0.21 wt .-% Al, balance iron. In another embodiment, not shown, a conclusion from this alloy is given.

A coil 22 is supplied with power from a current source 23, so that upon energization of the coil 22, a magnetic field is induced. The coil 22 is disposed around the magnetic core 21 so that, due to the induced magnetic field, the magnetic core 21 moves from a first position 24 indicated by the dashed line in FIG FIG. 1 is shown to a second position 25. In this embodiment, the first position 24 is a closed position and the second position is an open position. Consequently, the current 26 is controlled by the channel 27 from the actuator system 20.

In other embodiments, the actuator system 20 is a fuel injection valve of a gasoline engine or a diesel engine, or a direct fuel injection valve of a gasoline engine or a diesel engine.

The soft magnetic alloy of the magnetic core 21 has a content of chromium and manganese, which leads to a specific electrical resistance p in the annealed state of 0.572 μΩm. This higher resistivity allows for smaller shutter times on the actuator as eddy currents are reduced. At the same time, the alloy has a high saturation J (400 A / cm), measured at a magnetic field strength of 400 A / cm, of 2.137 T and a permeability μ _max of 1915, so that good soft magnetic properties are maintained.

The elements Si and Al of the alloy provide improved strength of the magnetic core 21 without significantly deteriorating the soft magnetic properties. The yield strength R _{p0.2 of} this alloy is 402 Mpa. The aluminum content enables a higher annealing temperature, which leads to good soft magnetic properties of a coercive force H _c of only 2.57 A / cm and a maximum permeability μ _max of 1915. A high permeability is desired because this leads to lower drive currents when using the alloy as the magnetic core of an actuator.

The content of Mo has been kept low to prevent the formation of carbides, which may lead to deterioration of the magnetic properties.

Table 1 shows compositions of various alloys according to the invention.

Semi-finished products were produced from these alloys by a process whose course in the FIG. 2 is shown.

In the in Fig. 2 shown flow diagram, the alloy is first melted in a melting process 1.

The alloy can be melted by various methods. In theory, all common techniques are possible, such as air melting or VIM (vacuum induction melting). For example, the arc furnace or inductive Techniques are used. Treatment with VOD (Vacuum Oxygen Decarburization) or AOD (Argon Oxygen Decarburization) or ESU (Electric Slag Remelting) improves the quality of the product.

For the preparation of the alloy, the VIM method is preferred because it allows the content of the alloying elements to be adjusted more accurately and non-metallic inclusions in the solidified alloy can be better avoided.

The melting process 1, depending on the semifinished product to be produced, is followed by a different series of process steps.

If tapes are to be produced from which parts are later punched, the ingot resulting from the melting process 1 is converted by pre-blocking 2 into a slab. Pre-blocking is understood to mean the forming of the ingot into a slab of rectangular cross-section by a hot rolling operation at a temperature of 1250 ° C. After pre-blocking, the scale formed on the surface of the slab is removed by grinding 3. The grinding 3 is followed by another hot rolling process 4, by which the slab is formed at a temperature of 1250 ° C in a band having a thickness of, for example, 3.5 mm. Subsequently, the impurities formed on the surface of the strip during hot rolling are removed by grinding or pickling 5, and the strip is cold-rolled 6 to the final thickness in the range of 0.1 to 2 mm. Finally, the strip is subjected to a final annealing 7 at a temperature of> 700 ° C. During final annealing, the lattice defects resulting from the forming processes heal and crystalline grains are formed in the microstructure.

Similarly, the manufacturing process is when turning parts are produced. Again, billets are made by pre-blocking 8 of the ingot with a square cross-section. The so-called pre-blocking takes place at a temperature of 1250 ° C. Subsequently, the scale formed during pre-blocking 8 is removed by grinding 9. This is followed by another hot rolling operation 10, by which the billets are converted into rods or wires up to a diameter of 13 mm. By straightening and peeling 11, on the one hand, distortions of the material are corrected and, on the other hand, the impurities forming during the hot rolling process 10 are removed on the surface. Finally, the material is also subjected to a final annealing 12 here.

The coercive force H _c was measured as a function of the annealing temperature for the alloys of Table 1. The results are in the FIG. 3 shown. From the FIG. 3 It can be seen that as the temperature increases, the coercive field strength initially decreases and increases at even higher temperatures, which are at the boundary to the two-phase region.

The annealing temperature is selected according to the composition, so that the coercive force remains low. For the alloy 3, which in connection with the FIG. 1 described, the annealing was carried out at a temperature of 760 ° C.

FIG. 4 shows the coercive force for the alloys 1 to 4, 8, 10, 11 and 13. The alloys 8, 10, 11 and 13 were also cold worked after hot rolling. The alloys 1 to 4 were only hot rolled. The FIG. 4 shows the influence of different alloying elements on H _c at different annealing temperatures. The increase of H _c shows the upper limit of the ferritic phase.

Alloys 2, 10, 11 and 13 having a lower H _c at higher annealing temperatures have an aluminum content of at least 0.68 wt%. Alloys 10 and 11 have a particularly low coercive force H _c of less than 1.5 A / cm at annealing temperatures above 850 ° C. These alloys have an aluminum content of 0.84% by weight and 0.92% by weight and a vanadium content of 2.51% by weight and 1.00% by weight, respectively.

In these alloys, the phase transition temperature is further shifted upwards. This has the advantage that the magnetic properties can be further improved by using a higher annealing temperature.

The properties of the specific electrical resistance in the annealed state, ρ _el , the coercive force H _c , the saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), and at a magnetic field strength of 400 A / cm, J ( 400 A / cm), the maximum _permeability μ _max , the yield strength R _m , R _p0.2 , the elongation at _rupture AL and the modulus of _elasticity were measured for the alloys of Table 1 and are summarized in Table 2.

The specific electrical resistance p of each alloy is above 0.5 μΩm. This leads to a suppression of the eddy currents, so that the alloys are suitable for actuator applications with short switching times. The yield strength was measured for the alloys 1 to 7 in the magnetically final annealed condition and is above 340 MPa for each alloy. These alloys can thus be used in applications where higher mechanical loads arise.

It can be seen from Table 2 that, in spite of the high alloying content of non-magnetic elements, the alloys have a high saturation J (400 A / cm)> 2.0 T, a high electrical resistivity ρ> 0.5 μΩm and a high yield strength R _p0.2 > 340 MPa. Consequently, these alloys are particularly suitable for magnetic cores in fast-switching actuator systems, such as fuel injection valves.

1st embodiment

An alloy according to a first embodiment consists of 18.1 wt .-% Co, 2.24 wt .-% Cr, 1.40 wt .-% Mn, 0.01 wt .-% Mo, 0.83 wt. % Si, 0.24 wt% Al, balance Fe and was prepared as described above. The alloy was annealed at 760 ° C and, when annealed, has a resistivity ρ _el of 0.542 μΩm, a coercive force H _c of 2.34 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm) of 2.029 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), 2.146 T, a maximum permeability μ _max of 2314, a yield strength R _m of 623 MPa, R _{p0 , 2} of 411 MPa, an elongation at break AL of 29.6% and an E modulus of 220 GPa.

2nd embodiment

An alloy according to a second embodiment consists of 18.2 wt .-% Co, 1.67 wt .-% Cr, 1.39 wt .-% Mn, 0.01 wt .-% Mo, 0.82 wt. % Si, 0.68 wt% Al, balance Fe and was prepared as described above. The alloy was annealed at 800 ° C and, when annealed, has a resistivity ρ _el of 0.533 μΩm, a coercive force H _c of 1.94 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), 2.019 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), 2.151 T, a maximum permeability μ _max of 1815 , a yield strength R _m of 661MPa, R _p0.2 of 385 MPa, an elongation at break AL of 25.4% and an E modulus of 221 GPa.

3rd embodiment

An alloy according to a third embodiment consists of 18.3 wt .-% Co, 2.62 wt .-% Cr, 1.37 wt .-% Mn, 0.01 wt .-% Mo, 0.85 wt. % Si, 0.21 wt.% Al, balance Fe and was prepared as described above. The alloy was annealed at 760 ° C and, when annealed, has a resistivity ρ _el of 0.572 μΩm, a coercive force H _c of 2.57 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 2.021 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), of 2.137 T, a maximum permeability μ _max of 1915, a yield strength R _m of 632 MPa, R _{p0 , 2} of 402 MPa, an elongation at break AL of 28.0% and an E modulus of 217 GPa.

4th embodiment

An alloy according to a fourth embodiment consists of 18.3 wt .-% Co, 2.42 wt .-% Cr, 1.45 wt .-% Mn, 0.01 wt .-% Mo, 0.67 wt. % Si, 0.23 wt% Al, balance Fe and was prepared as described above. The alloy was annealed at 730 ° C and, when annealed, has a resistivity ρ _el of 0.546 μΩm, a coercive force H _c of 2.73 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 2.037 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), 2.156T, a maximum permeability μ _max of 2046, a yield strength R _m of 615 MPa, R _p0.2 of 395 MPa, an elongation at break AL of 29.5% and an E modulus of 223 GPa on.

5th embodiment

An alloy according to a fifth embodiment consists of 15.40 wt .-% Co, 2.34 wt .-% Cr, 1.27 wt .-% Mn, 0.85 wt .-% Si, 0.23 wt. % Al, balance Fe and was prepared as described above. The alloy was annealed at 760 ° C and, when annealed, has a resistivity ρ _el of 0.5450 μΩm, a coercive force H _c of 1.30 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 1.986 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), of 2.105T and a maximum permeability μ _max of 3241.

6th embodiment

An alloy according to a sixth embodiment consists of 18.10 wt .-% Co, 2.30 wt .-% Cr, 1.37 wt .-% Mn, 0.83 wt .-% Si, 0.24 wt. % Al, balance Fe and was prepared as described above. The alloy was annealed at 760 ° C and, when annealed, has a resistivity ρ _el of 0.5591 μΩm, a coercive force H _c of 1.39 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 2.027 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), of 2.138 T and a maximum permeability μ _max of 2869.

7th embodiment

An alloy according to a seventh embodiment consists of 21.15 wt .-% Co, 2.31 wt .-% Cr, 1.38 wt .-% Mn, 0.84 wt .-% Si, 0.23 wt. % Al, balance Fe and was prepared as described above. The alloy was annealed at 760 ° C and, when annealed, has a resistivity ρ _el of 0.5627 μΩm, a coercive force H _c of 1.93 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 2.066 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), of 2.165 T and a maximum permeability μ _max of 1527.

In the eighth to thirteenth embodiments, the sum of the additions is slightly higher and is between 6 wt .-% and 9 wt .-%. These alloys each have a specific electrical resistance ρ _el ≥ 0.60 μΩm in the annealed state.

8th embodiment

An alloy according to an eighth embodiment consists of 18.0 wt% Co, 2.66 wt% Cr, 1.39 wt% Mn, <0.01 wt% Mo, 0.87 wt. % Si, 0.17 wt% Al, 1.00 wt% V, balance Fe and was prepared as described above. This alloy was cold worked even after hot rolling. The alloy was annealed at 780 ° C and, when annealed, has a resistivity ρ _el of 0.627 μΩm, a coercive force H _c of 1.40 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 1.977 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), 2.088 T, a maximum permeability μ _max of 2862, a yield strength R _m of 605 MPa, R _p0.2 of 374 MPa, an elongation at break AL of 29.7% and an E modulus of 222 GPa.

9th embodiment

An alloy according to a ninth embodiment consists of 18.0% by weight of Co, 2.60% by weight of Cr, 1.35% by weight of Mn, 0.99% by weight of Mo, 0.84% by weight. % Si, 0.17 wt% Al, <0.01 wt% V, balance Fe and was prepared as described above. In addition, this alloy was cold worked. The alloy was annealed at 780 ° C and, when annealed, has a resistivity ρ _el of 0.604 μΩm, a coercive force H _c of 2.13 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 21.969 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), 2.092 T, a maximum permeability μ _max of 1656, a yield strength R _m of 636 MPa, R _{p0 , 2} of 389 MPa, an elongation at break AL of 29.2% and an E-modulus of 222 GPa.

10th embodiment

An alloy according to a tenth embodiment consists of 18.0 wt% Co, 1.85 wt% Cr, 1.33 wt% Mn, <0.01 wt% Mo, 0.86 wt. % Si, 0.84 wt% Al, 2.51 wt% V, balance Fe and was prepared as described above. Thereafter, the alloy was cold worked. The alloy was annealed at 870 ° C and, when annealed, has a resistivity ρ _el of 0.716 μΩm, a coercive field strength H _c of 0.95 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 1.920 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A) / cm), from 2.015 T, a maximum permeability μ _max of 4038. This alloy of the tenth embodiment has a particularly advantageous combination of a high resistivity ρ _el of 0.716 μΩm, a low coercive force H _c of 0.95 A / cm, and a high saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), from 1.920 T up.

11th embodiment

An alloy according to an eleventh embodiment consists of 12.0 wt% Co, 2.65 wt% Cr, 1.38 wt% Mn, <0.01 wt% Mo, 0.85 wt. % Si, 0.92 wt.% Al, 1.00 wt.% V, remainder Fe and was prepared as described above and additionally clearly deformed. The alloy was annealed at 820 ° C and, when annealed, has a resistivity ρ _el of 0.658 μΩm, a coercive force H _c of 0.72 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 1.880 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), 2.008 T, a maximum permeability μ _max of 5590, a yield strength R _m of 525 MPa, R _{p0 , 2} of 346 MPa, an elongation at break AL of 33.5% and an E modulus of 216 GPa.

The alloy according to the eleventh embodiment has a particularly advantageous combination of high resistivity ρ _el of 0.658 μΩm, low coercive force H _c of 0.72 A / cm, and high saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), 1.880 T on.

12th embodiment

The twelfth alloy is not according to the invention since the Co content is greater than 22% by weight.

13th embodiment

An alloy according to a thirteenth embodiment consists of 18.0 wt% Co, 3.00 wt% Cr, 1.32 wt% Mn, <0.01 wt% Mo, 0.86 wt. % Si, 0.84 wt% Al, 2.01 wt% V, balance Fe and was prepared as described above and cold worked after hot rolling. The alloy was annealed at 820 ° C and, when annealed, has a resistivity ρ _el of 0.769 μΩm, a coercive force H _c of 1.14 A / cm, a saturation J at a magnetic field strength of 160 A / cm, J (160 A / cm), of 1.896 T, a saturation J at a magnetic field strength of 400 A / cm, J (400 A / cm), of 1, 985 T, a maximum permeability μ _max of 3499, a yield strength R _m of 674 MPa, R _p0.2 of 396 MPa, an elongation at break AL of 33.3% and an E-modulus of 218 GPa.

20

Aktorsystem

21

Magnetkern

22

Spule

23

Stromquelle

24

erste Position des Magnetkerns

25

zweite Position des Magnetkerns

26

Strom

27

Kanal

Tabelle 1 Legierung Fe Co (Gew.-%) Summe Zulegierungen Cr (Gew.-%) Mn (Gew.-%) Si (Gew.-%) Mo (Gew.-%) Al (Gew.-%) V (Gew.-%) 1 Rest 18,1 4,73 2,24 1,40 0,83 0,01 0,24 <0,01 2 Rest 18,2 4,58 1,67 1,39 0,82 0,01 0,68 <0,01 3 Rest 18,3 5,09 2,62 1,37 0,85 0,01 0,21 <0,01 4 Rest 18,3 4,78 2,42 1,45 0,67 0,01 0,23 <0,01 5 Rest 15,40 4,69 2,34 1,27 0,85 0,001 0,23 <0,01 6 Rest 18,10 4,74 2,30 1,37 0,83 0,001 0,24 <0,01 7 Rest 21,15 4,76 2,31 1,38 0,84 0,001 0,23 <0,01 8 Rest 18,0 6,18 2,66 1,39 0,87 <0,01 0,17 1,00 9 Rest 18,0 6,18 2,60 1,35 0,84 0,99 0,17 <0,01 10 Rest 18,0 7,38 1,85 1,33 0,86 <0,01 0,84 2,51 11 Rest 12,0 6,78 2,65 1,38 0,85 <0,01 0,92 1,00 12* Rest 25,0 5,58 1,57 0,96 0,93 <0,01 1,02 1,00 13 Rest 18,0 8,18 3,00 1,32 0,86 <0,01 0,84 2,01 *nicht erfindungsgemäß Tabelle 2 Legierung Glühtemperatur (°C) ρ (µΩm) H_c (A/cm) J(160) (T) J(400) (T) µ_max R_m (Mpa) Rp_0,2 (Mpa) AL (%) E-Modul (Gpa) 1 760 0,542 2,34 2,029 2,146 2314 623 411 29,6 220 2 800 0,533 1,94 2,019 2,151 1815 661 385 25,4 221 3 760 0,572 2,57 2,021 2,137 1915 632 402 28,0 217 4 730 0,546 2,73 2,037 2,156 2046 615 395 29,5 223 5 760 0,545 1,30 1,986 2,105 3241 - - - - 6 760 0,559 1,39 2,027 2,138 2869 - - - - 7 760 0,563 1,93 2,066 2,165 1527 - - - - 8 780 0,627 1,40 1,977 2,088 2862 605 374 29,7 222 9 780 0,604 2,13 1,969 2,092 1656 636 389 29,2 222 10 870 0,716 0,95 1,920 2,015 4038 - - - - 11 820 0,658 0,72 1,880 2,008 5590 525 346 33,5 216 12* 870 0,628 1,25 1,989 2,075 1793 - - - - 13 820 0,769 1,14 1,896 1,985 3499 674 396 33,3 218 *nicht erfindungsgemäß LIST OF REFERENCE NUMBERS

20

actuator systems

21

magnetic core

22

Kitchen sink

23

power source

24

first position of the magnetic core

25

second position of the magnetic core

26

electricity

27

channel

Table 1 alloy Fe Co (% by weight) Total allowances Cr (wt.%) Mn (wt%) Si (wt.%) Mo (wt.%) Al (wt.%) V (% by weight) 1 rest 18.1 4.73 2.24 1.40 0.83 0.01 0.24 <0.01 2 rest 18.2 4.58 1.67 1.39 0.82 0.01 0.68 <0.01 3 rest 18.3 5.09 2.62 1.37 0.85 0.01 0.21 <0.01 4 rest 18.3 4.78 2.42 1.45 0.67 0.01 0.23 <0.01 5 rest 15.40 4.69 2.34 1.27 0.85 0.001 0.23 <0.01 6 rest 18,10 4.74 2.30 1.37 0.83 0.001 0.24 <0.01 7 rest 21.15 4.76 2.31 1.38 0.84 0.001 0.23 <0.01 8th rest 18.0 6.18 2.66 1.39 0.87 <0.01 0.17 1.00 9 rest 18.0 6.18 2.60 1.35 0.84 0.99 0.17 <0.01 10 rest 18.0 7.38 1.85 1.33 0.86 <0.01 0.84 2.51 11 rest 12.0 6.78 2.65 1.38 0.85 <0.01 0.92 1.00 12 * rest 25.0 5.58 1.57 0.96 0.93 <0.01 1.02 1.00 13 rest 18.0 8.18 3.00 1.32 0.86 <0.01 0.84 2.01 * not according to the invention alloy Annealing temperature (° C) ρ (μΩm) _Hc (A / cm) J (160) (T) J (400) (T) μ _max R _m (Mpa) Rp _0.2 (Mpa) AL (%) Modulus of elasticity (Gpa) 1 760 0.542 2.34 2,029 2,146 2314 623 411 29.6 220 2 800 0.533 1.94 2,019 2,151 1815 661 385 25.4 221 3 760 0.572 2.57 2,021 2,137 1915 632 402 28.0 217 4 730 0.546 2.73 2.037 2,156 2046 615 395 29.5 223 5 760 0.545 1.30 1,986 2,105 3241 - - - - 6 760 0,559 1.39 2,027 2,138 2869 - - - - 7 760 0.563 1.93 2,066 2,165 1527 - - - - 8th 780 0.627 1.40 1,977 2,088 2862 605 374 29.7 222 9 780 0.604 2.13 1,969 2,092 1656 636 389 29.2 222 10 870 0.716 0.95 1,920 2,015 4038 - - - - 11 820 0,658 0.72 1,880 2,008 5590 525 346 33.5 216 12 * 870 0.628 1.25 1,989 2,075 1793 - - - - 13 820 0.769 1.14 1,896 1,985 3499 674 396 33.3 218 * not according to the invention

Claims (46)

1. Soft magnetic alloy, consisting of 10 % by weight ≤ Co ≤ 22 % by weight, 0 % by weight ≤ V ≤ 4 % by weight, 1.5 % by weight ≤ Cr ≤ 5 % by weight, 1 % by weight ≤ Mn ≤ 2 % by weight, 0 % by weight ≤ Mo ≤ 1 % by weight, 0.5 % by weight ≤ Si ≤ 1.5 % by weight, 0.1 % by weight ≤ Al ≤ 1.0 % by weight, rest iron plus unavoidable impurities.
2. Soft magnetic alloy according to claim 1,
   characterised by
   a cobalt content of 14 % by weight ≤ Co ≤ 22 % by weight.
3. Soft magnetic alloy according to claim 2,
   characterised by
   a cobalt content of 14 % by weight ≤ Co ≤ 20 % by weight.
4. Soft magnetic alloy according to any of the preceding claims,
   characterised by
   a vanadium content of 0 % by weight ≤ V ≤ 2 % by weight.
5. Soft magnetic alloy according to any of the preceding claims,
   characterised by
   a molybdenum content of 0 % by weight < Mo ≤ 0.5 % by weight.
6. Soft magnetic alloy according to any of the preceding claims,
   characterised by
   a manganese content of 1.25 % by weight ≤ Mn ≤ 1.5 % by weight.
7. Soft magnetic alloy according to any of the preceding claims,
   characterised by
   a silicon content of 0.5 % by weight ≤ Si ≤ 1.0 % by weight.
8. Soft magnetic alloy according to any of the preceding claims,
   characterised by
   an aluminium plus silicon content of 0.6 % by weight ≤ Al+Si ≤ 2 % by weight.
9. Soft magnetic alloy according to any of the preceding claims,
   characterised by
   a chromium plus manganese plus molybdenum plus aluminium plus silicon plus vanadium content of 4.0 % by weight ≤ Cr+Mn+Mo+Al+Si+V ≤ 9.0 % by weight.
10. Soft magnetic alloy according to any of the preceding claims,
    characterised in that
    0 % by weight ≤ V ≤ 2.0 % by weight, 1.6 % by weight ≤ Cr ≤ 2.5 % by weight, 1.25 % by weight ≤ Mn ≤ 1.5 % by weight, 0 % by weight ≤ Mo ≤ 0.02 % by weight, 0.6 % by weight ≤ Si ≤ 0.9 % by weight and 0.2 % by weight ≤ Al ≤ 0.7 % by weight.
11. Soft magnetic alloy according to any of the preceding claims;
    characterised in that
    0 % by weight ≤ V ≤ 0.01 % by weight, 2.3 % by weight ≤ Cr ≤ 3.0 % by weight, 1.25 % by weight ≤ Mn ≤ 1.5 % by weight, 0.75 % by weight ≤ Mo ≤ 1 % by weight, 0.6 % by weight ≤ Si ≤ 0.9 % by weight and 0.1 % by weight ≤ Al ≤ 0.2 % by weight.
12. Soft magnetic alloy according to any of the preceding claims,
    characterised in that
    0.75 % by weight ≤ V ≤ 2.75 % by weight, 2.3 % by weight ≤ Cr ≤ 3.5 % by weight, 1.25 % by weight ≤ Mn ≤ 1.5 % by weight, 0 % by weight ≤ Mo ≤ 0.01 % by weight, 0.6 % by weight ≤ Si ≤ 0.9 % by weight and 0.7 % by weight ≤ Al ≤ 1.0 % by weight.
13. Soft magnetic alloy according to any of the preceding claims,
    characterised in that
    the finish-annealed alloy has an elongation A_L > 2% in a tensile test.
14. Soft magnetic alloy according to claim 13,
    characterised in that
    the finish-annealed alloy has an elongation A_L > 20% in a tensile test.
15. Soft magnetic alloy according to any of the preceding claims,
    characterised by
    a resistivity ρ > 0.50 µΩm.
16. Soft magnetic alloy according claim 15,
    characterised by
    a resistivity ρ > 0.55 µΩm.
17. Soft magnetic alloy according to claim 16,
    characterised by
    a resistivity ρ > 0.60 µΩm.
18. Soft magnetic alloy according to claim 17,
    characterised by
    a resistivity ρ > 0.65 µΩm.
19. Soft magnetic alloy according to any of the preceding claims,
    characterised by
    a yield point R_p0.2 > 340 MPa.
20. Soft magnetic alloy according to any of the preceding claims,
    characterised by
    a saturation with J(400 A/cm) > 1.90 T.
21. Soft magnetic alloy according to any of the preceding claims,
    characterised by
    a saturation with J(400 A/cm) > 2.00 T.
22. Soft magnetic alloy according to any of the preceding claims,
    characterised by
    a coercitive field strength H_c < 3.5 A/cm.
23. Soft magnetic alloy according to claim 22,
    characterised by
    a coercitive field strength H_c < 2.0 A/cm.
24. Soft magnetic alloy according to any of the preceding claims,
    characterised by
    a maximum permeability µ_max > 1000.
25. Soft magnetic alloy according to claim 24,
    characterised by
    a maximum permeability µ_max > 2000.
26. Soft magnetic core for an electromagnetic actuator, made of an alloy according to any of claims 1 to 25.
27. Soft magnetic alloy for a magnetic valve of an internal combustion engine, made of an alloy according to any of claims 1 to 25.
28. Soft magnetic alloy for a fuel injection valve of an internal combustion engine, made of an alloy according to any of claims 1 to 25.
29. Soft magnetic alloy for a direct injection valve of a spark ignition engine, made of an alloy according to any of claims 1 to 25.
30. Soft magnetic alloy for a direct injection valve of a diesel engine, made of an alloy according to any of claims 1 to 25.
31. Fuel injection valve of an internal combustion engine, with a component made of a soft magnetic alloy according to any of claims 1 to 25.
32. Fuel injection valve according to claim 31,
    characterised in that
    the fuel injection valve is a direct fuel injection valve of a spark ignition engine.
33. Fuel injection valve according to claim 31,
    characterised in that
    the fuel injection valve is a direct fuel injection valve of a diesel engine.
34. Soft magnetic rotor for an electric motor, made of an alloy according to any of claims 1 to 25.
35. Soft magnetic stator for an electric motor, made of an alloy according to any of claims 1 to 25.
36. Soft magnetic rotor for an electric motor, made of an alloy according to any of claims 1 to 25.
37. Soft magnetic component for an electromagnetic valve control on an inlet valve or an outlet valve used in an engine compartment, made of an alloy according to any of claims 1 to 25.
38. Yoke part for an electromagnetic actuator, made of an alloy according to any of claims 1 to 25.
39. Yoke part for a solenoid valve, made of an alloy according to any of claims 1 to 25.
40. Method for the production of semi-finished product of a cobalt-iron alloy,
    wherein workpieces are first produced by melting (1) and hot forming (4, 10) from a soft magnetic alloy consisting of 10 % by weight ≤ Co ≤ 22 % by weight, 0 % by weight ≤ V ≤ 4 % by weight, 1.5 % by weight ≤ Cr ≤ 5 % by weight, 1 % by weight ≤ Mn ≤ 2 % by weight, 0 % by weight ≤ Mo ≤ 1 % by weight, 0.5 % by weight ≤ Si ≤ 1.5 % by weight, 0.1 % by weight ≤ Al ≤ 1.0 % by weight, rest iron plus unavoidable impurities,
    wherein a finish-annealing process (7, 12) is carried out.
41. Method according to claim 40,
    characterised in that
    the finish-annealing process (7, 12) is carried out within a temperature range between 700°C and 1100°C.
42. Method according to claim 41,
    characterised in that
    the finish-annealing process (7, 12) is carried out within a temperature range between 750°C and 850°C.
43. Method according to any of claims 40 to 42,
    characterised in that
    the finish-annealing process is carried out such that the finish-annealed alloy has deformation parameters of an elongation A_L > 2% in a tensile test.
44. Method according to claim 43,
    characterised in that
    the finish-annealing process is carried out such that the finish-annealed alloy has deformation parameters of an elongation A_L > 20% in a tensile test.
45. Method according to any of claims 40 to 44,
    characterised in that
    the alloy is cold-formed before the finish-annealing process (7, 12).
46. Method according to any of claims 40 to 45,
    characterised in that
    the alloy is finish-annealed in the presence of an inert gas or hydrogen or in a vacuum.

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