DE102008053310A1 - Soft-magnetic workpiece with wear-resistant layer, used to make fuel injection- or solenoid valve, includes core of crystalline iron-cobalt alloy - Google Patents

Abstract

The surface region (1, 2, 3) of the workpiece (10) has a wear-resistant layer (4). The core is made of soft magnetic material (7), which is novel in being a crystalline iron-cobalt alloy. The wear-resistant layer includes one or more of the following: chromium, nickel, carbon- or nitrogen-containing compounds. The core contains iron and the following elements, their proportions being expressed as percentages by weight. Co 10-22, V 0-4, Cr 1.5-5, Mn 0-2, Mo 0-1, Si 0.5-1.5, Al 0.1-1.0. The sum of Cr, Mn, Mo, Al, Si and V lies in the range 4.0-9.0 wt%. Further detailed, quantified relationships are provided, which limit the alloy composition. In the finally-annealed state the ultimate extension is 20% with necking reduction of 50%. The tensile limit is 340 MPa and the cobalt content is 14-22 wt%. The coercivity H cis less than 3.5 A/cm; H is less than 2.0. The maximum permeability exceeds 1000-2000. The core includes a corrosion-resistant FeCoCr alloy. Further variant compositions are proposed. Polarization J of the core in a field H of 160 A/cm exceeds 1.6 T. The saturated polarization J sof the core in a field of 160 A/cm exceeds 1.7 T. Further minimum values of polarization of up to 1.8 T are proposed for fields up to 600A/cm. The specific electrical resistance of the core exceeds 0.4-0.58 mu ohm m. The core is used for fuel-injection, in a petrol or diesel engine. It is used in a valve for direct fuel injection. It is used as the armature or actuator of a solenoid valve. It is used in the pole piece or return magnetic circuit of a solenoid valve. It is compatible with fuel/alcohol mixtures, the fuel being petrol or diesel oil. The alcohol is methanol, ethanol or their mixtures. The fuel is a petrol/alcohol mixture, the ratio being 85/15 or 80/20. The alloy undergoes final annealing at 700-1100[deg] C or 750-850[deg] C. Under test, its ultimate extension is up to 2% or up to 20%. It is subjected to cold forging before final annealing. The latter takes place under inert gas, hydrogen or vacuum. The wear-resistant layer is applied by vaporization of a nickel- or chromium-containing alloy. Plasma-nitriding, gas-nitriding or nitro-carburization is used for its application. It may be added by chemical deposition or electroplating, following final annealing. An independent claim IS INCLUDED FOR the corresponding method of manufacture.

Description

The The invention relates to a workpiece made of soft magnetic Material having a surface area which has a Wear protection layer has. The soft magnetic material is for a workpiece core of the workpiece intended.

Such workpieces with a workpiece core, which has the soft magnetic material and a surface region, which has a wear protection layer is from the document EP 0 683 862 B1 , which discloses an electromagnetically operable valve, known. The workpiece of soft magnetic material forms here the armature of the electromagnetically operable valve, which is constructed of a soft magnetic material and has a wear protection layer.

From the publication DE 44 21 937 C1 there is known a "method for treating at least part of soft magnetic, wear resistant part and its use", the method being particularly suitable for the treatment of soft magnetic parts of electromagnetic fuel injection valves. For this soft magnetic workpieces are made of chrome steel and then coated with a wear-resistant layer on highly stressed surfaces.

task the invention is the properties of the known workpieces, especially in electromagnetic valves by using new soft magnetic materials with appropriate hardening and wear-resistant layers, in which as Workpiece cores materials are used, the one high saturation induction with simultaneous high electrical Have resistance for the soft magnetic material. It is another object of the invention, a method for producing such Specify workpieces.

These The object becomes with the characteristics of the object of the independent Claims solved. Advantageous developments The invention will become apparent from the dependent claims.

According to the invention a workpiece made of soft magnetic material with a wear-resistant coating and a method for producing the workpiece specified. In this case, the workpiece has a surface area on, which has a wear protection layer. Furthermore the workpiece has a workpiece core, the from the soft magnetic material. The soft magnetic workpiece core is made of a crystalline FeCo alloy.

One Such workpiece combines the advantages of a soft magnetic Alloy based on crystalline iron cobalt with the advantages a wear-resistant surface area, the can be chosen so that meeting each other Stop surfaces of such workpieces also after longer operating time not due to wear in undesirably enlarged or deformed become. Especially with moving workpieces remain the geometric dimensions and contours despite multiple and also high-frequency collision of surface areas with wear protection layers of the workpieces with soft magnetic cores almost constant. Besides that is a soft magnetic core of a crystalline FeCo alloy a guarantee that a high saturation induction at the same time high electrical resistance, such as a movable workpiece reaches an injection valve can be.

In a preferred embodiment of the invention, the Wear protection layer on chromium, for example by means of Electroplating on the workpiece core in surface areas is applied, for example, to a vertical valve axis Form stop surfaces, or on the longitudinal axis running sliding lateral surfaces of the workpiece be applied.

Also it is possible that the wear protection layer a nickel alloy, either galvanic or by Plasma nitriding or by gas nitriding on the appropriate abutting surface areas or on against each other sliding surface areas - for example a cylindrical shell - is applied.

In addition, it is possible that the wear protection layer comprises a carbonaceous compound, which are applied by means of plasma carburizing or gas carburizing on the corresponding wear-prone surface areas of a workpiece with soft magnetic core based on iron-cobalt alloys. When producing wear protection layers by means of carbonitriding, the workpiece is introduced into a gas reactor, which preferably has an ammonia and a carbon compound such as CO or CO ₂ . In such processes, a wear protection layer is achieved which comprises carbon- and nitrogen-containing compounds.

In a preferred embodiment of the invention, the workpiece as a soft-magnetic workpiece core based on the crystalline FeCo alloy has a material with a composition which is essentially iron and 10% by weight ≦ Co ≦ 22% by weight, 0% by weight. % ≦ V ≦ 4 wt%, 1.5 wt% ≤ Cr ≤ 5 wt%, 0 wt% ≤ Mn ≤ 2 wt%, 0 wt% ≤ Mo ≤ 1 wt% .-%, 0.5 Wt .-% ≤ Si ≤ 1.5 wt .-%, 0.1 wt .-% ≤ Al ≤ 1.0 wt .-%, wherein the content of the elements chromium and manganese and molybdenum and aluminum and silicon and Vanadium is 4.0 wt% ≤ (Cr + Mn + Mo + Al + Si + V) ≤ 9.0 wt%.

These Soft magnetic alloy according to the invention for the workpiece core is opposite to the purely binary CoFe alloy has a higher resistivity, which leads to a suppression of eddy currents, at the lowest possible lowering of the saturation polarization. This is done by adding the non-magnetic elements reached. Furthermore, due to the content of aluminum, the alloy has and silicon to a higher strength. 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 crystalline cobalt-iron-based soft magnetic alloy for an actuator system are different. A higher cobalt content leads to a higher saturation magnetization J _S of approximately 9 mT per 1 wt.% Co (starting from 17 wt.% Co) in the purely binary alloy, thus allowing a smaller overall volume and higher system integration or higher actuator forces same size. At the same time, however, the cost of the alloy increases. With increasing Co content, the soft magnetic properties deteriorate, such as permeability up to a Co content of 25 wt .-%. In addition, the alloy for such actuator systems should also have a high electrical resistivity and good soft magnetic properties. As indicated above, such an alloy has a cobalt content of 10% by weight ≦ Co ≦ 22% by weight. A lower cobalt content reduces the raw material cost of the alloy, so that reduced cobalt alloys are suitable for high cost pressure applications, such as in the automotive industry. The maximum permeability is high within this range, which leads to the use as an actuator to lower and thus more favorable drive currents.

In a further embodiment of the invention, the alloy has a cobalt content of 14% by weight ≦ Co ≦ 22% by weight or a cobalt content of 14% by weight ≦ Co ≦ 20% by weight. The above-mentioned soft magnetic alloy of the workpiece core has a content of chromium and manganese, which leads to egg nem higher electrical resistivity ρ 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 of the workpiece core has a high saturation and a high maximum permeability μ _max , so that good soft-magnetic properties can be maintained in this workpiece core despite coating with a wear-resistant layer in surface regions of the workpiece.

The Elements Si and Al of the alloy see improved strength the alloy before, without the soft magnetic properties be significantly worsened. By the addition of Si and Al allows the strength of the alloy by solid solution hardening increase significantly without a significant deterioration to cause the soft magnetic properties.

The aluminum content of the workpiece core according to the invention allows a higher annealing temperature, which leads to good soft magnetic properties with respect to the coercive force H _c and the maximum permeability μ _max . High permeability is desired when this leads to lower drive currents when using the alloy as the magnetic core of an actuator. In a further embodiment of the invention, the alloy of the workpiece core has a silicon content of 0.5% by weight ≦ Si ≦ 1.0% by weight.

Of the Content of Mo and V is kept correspondingly lower, to the formation of carbides within the soft magnetic workpiece core to avoid the deterioration of the magnetic properties could lead. For this purpose, in a further embodiment According to the invention, the soft magnetic alloy has a vanadium content of 0 wt% ≤ V ≤ 2 wt%, and a molybdenum content between 0 wt .-% ≤ Mo ≤ 0.5 wt .-% and / or a Manganese content between 1.25% by weight ≤ Mn ≤ 1.5% by weight on. In addition to Cr and Mn, the molybdenum content is favorable, because this content of molybdenum by a good ratio from resistance increase to saturation decrease in the work piece core distinguished.

In In another embodiment, the alloy of Worker core molybdenum on, in particular a Molybdenum content of 0.001 wt% ≤ Mo ≤ 0.1 Wt .-%. Furthermore, it is envisaged that the content of aluminum and silicon of 0.6% by weight ≦ Al + Si ≦ 2% by weight so that brittleness and processing problems, at higher total levels of aluminum and silicon can be avoided. The content of chromium and manganese and molybdenum and aluminum and silicon lies in one embodiment of the invention, between 6.0 wt% ≤ Cr + Mn + Mo + Al + Si + V ≤ 9.0 wt%.

In a further embodiment of the invention, the soft-magnetic workpiece core of the workpiece according to the invention is based on of the FeCo crystalline alloy has a content of 0 wt% ≤ V ≤ 0.01 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% is 14 wt% ≤ Co ≤ 22.

A modified alloy composition of the soft magnetic workpiece core based on the crystalline FeCo alloy has a content of 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 .-% 14 wt .-% ≤ Co ≤ 22 on.

After all The workpiece core can also be made of an alloy on the Base made of the crystalline FeCo alloy, with a Content of 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 0.7 wt% ≤ Al ≤ 1.0 wt% 14 wt% ≤ Co ≤ 22 having.

alloys with the above compositions have a specific electrical resistance of ρ> 0.4 μm or larger 0.5 μΩm or even 0.58 μΩm on. Workpieces can be realized with these values which are extremely useful when used as a magnetic core of an actuator system have low eddy currents. this makes possible the use of the alloy in actuator systems with high-frequency Switching times.

The proportion of the elements aluminum and silicon in the alloy _according to the invention for the work piece _core leads to an alloy with a yield strength of R _p0.2 > 340 Mpa. This higher strength of the alloy can extend the service life of the alloy when used as the workpiece core of an actuator system. This is advantageous in the use of the alloy in high-frequency actuator systems, such as fuel injection valves in internal combustion engines.

In a further embodiment of the invention, the soft magnetic workpiece core has good soft magnetic properties, as well as a high strength and a high electrical resistivity. In this case, the workpiece core can have a saturation of J (400 A / cm)> 2.00 T or> 2.10 T and / or a coercive force H _c <3.5 A / cm or H _c <2.0 A / cm and / or reach a maximum permeability of μ _max > 1000 or μ _max > 2000.

In a preferred embodiment of the invention, the Workpiece a soft magnetic workpiece core based on the crystalline FeCo alloy a corrosion resistant FeCoCr alloy on. The chromium content of such an alloy is between 6 and 16%, with the total composition of the workpiece core essentially iron and 3% <Co <20%, 6% <Cr <16%, 0% ≤ S ≤ 0.5%, 0% ≦ Mo ≦ 3%, 0% ≦ Si ≦ 3.5%, 0% ≦ Al ≦ 4.5%, 0% ≦ Mn ≦ 4.5%, 0% ≤ Me ≤ 6%, where Me is one or more of the Elements Sn, Zn, W, Ta, Nb, Zr and Ti, 0% ≤ V ≤ 4.5%, 0% Ni ≦ 5%, 0% ≦ C <0.05%, 0% ≦ Cu <1%, 0% ≦ P <0.1%, 0% ≦ N <0.5%, 0% ≦ 0 < 0.05%, 0% <B <0.01%. In this alloy, a preferred cobalt content is soft magnetic Workpiece core between 6% <Co <15% advantageous, while the relatively high chromium content between 6% <Cr <16% a significant improvement in the corrosion resistance supplies. The relatively high proportion of Cr and Mn allow a strong increase in resistance at a slight saturation decrease.

Next Cr and Mn are low in molybdenum content, because this content of molybdenum by a good ratio characterized by resistance increase to saturation decrease. In one embodiment of the invention is therefore the Proportion of molybdenum in the soft-magnetic workpiece core 0 wt% ≤ Mo ≤ 1 wt% or 1 wt% ≤ Mo ≤ 2 wt%. In addition, the alloy can have a certain content of manganese, as well as sulfur. These two elements lead to an improved machinability of the alloy. The alloy exhibits preferably in the soft-magnetic workpiece core 0.01% ≤ Mn ≤ 1% and 0.005% ≤ S ≤ 0.5% on.

sulfur is almost insoluble in iron. Iron sulfide, however, forms a low-melting eutectic at a temperature of 1188 ° C, which accumulates at the grain boundaries and during hot rolling at 800 ° C. lead to red brittleness up to 1000 ° C can. With additional addition of manganese from a ratio of Mn / S> 1.7, which a ratio of 1: 1 in atomic percent, the all sulfur bound to a melting at 1600 ° C MnS. MnS has a much higher melting point than FeS and becomes elongated after rolling and row. Manganese sulfides have a lubricating effect on a cutting wedge and form impurities in the Steel, which leads to shorter chips can. Since the Spanbarkeit the inventive Alloy is improved, it is believed that in this alloy MnS precipitates are formed, which thus have a similar Function, as with corresponding MnS impurities in steel.

Furthermore, it is provided that the workpiece core of the workpiece comprises chromium and molybdenum with 11% ≦ Cr + Mo ≦ 19%. In addition, it is intended to work with an alloy in the workpiece core, in which the sum of Si + 1.3 Al + 1.3 Mn + 1.7 Sn + 1.7 Zn + 1.3 V ≤ 3.5%. It can thus be achieved that a saturation magnetization J of the workpiece core at a magnetic field H of 160 A / cm is greater than 1.6 T. If the chromium content changes slightly, a saturation magnetization J greater than 1.7 T can be achieved at a magnetic field strength H 160 A / cm. With a correspondingly higher magnetic field strength H of 600 A / cm, a saturation polarization J of more than 1.75 T or even 1.8 T can be achieved.

The Workpiece made of workpiece core and surface areas with a wear-resistant coating can in a fuel injection system arranged and for use in a gasoline engine, a diesel engine, preferably in a direct fuel injection valve be. In general, the workpiece with the wear protection layer in surface areas of a soft magnetic core for an electromagnetic actuator are used, in particular for an armature of an electromagnetically actuated Valve. It is also possible, such an inventive Workpiece as a return part of a solenoid valve provided.

there The workpiece can be suitable for use in an environment be, which has a mixture of fuel and alcohol, wherein the fuel is gasoline or diesel and the alcohol is from the group Methanol, ethanol and a mixture of methanol and ethanol is. In this case, preferably, a mixture of 85% gasoline and 15% Alcohol or a mixture used 80% gasoline and 20% alcohol.

In a method of manufacturing a crystalline cobalt-iron alloy workpiece, first, by melting and hot-working, a soft magnetic alloy workpiece core is prepared, which is substantially iron and 10% by weight ≦ Co ≦ 22% by weight Wt% ≤ V ≤ 4 wt%, 1.5 wt% ≤ Cr ≤ 5 wt%, 0 wt% ≤ Mn ≤ 2 wt%, 0 wt% ≤ Mo ≦ 1 wt%, 0.5 wt% ≤ Si ≤ 1.5 wt%, 0.1 wt% ≤ Al ≤ 1.0 wt%, ≤ Si ≤ 1.5 wt% %, 0.1% by weight ≦ Al ≦ 1.0% by weight. After or during a final annealing, a wear protection layer is applied to a surface region of the workpiece core ( 4 ) applied.

Such a final annealing is preferably carried out at a temperature T between 700 ° C ≤ T ≤ 1100 ° C. A preferred temperature range T is between 750 ° C ≤ T ≤ 850 ° C. The final annealing is carried out such that the material of the workpiece core after the final annealing has deformation parameters in the tensile test of an elongation at break of A _L > 2%, preferably A _L > 20%.

The Final annealing itself is preferably under inert gas, such as nitrogen, or under hydrogen or under vacuum, while for the production of the protective layer a gas separation with nitrogen compounds or with carbon compounds and / or vapor deposition of alloys containing nickel or chromium is carried out. Furthermore, it is possible to Wear protection layer by means of plasma nitriding, gas nitriding or nitrocarburizing. As mentioned above, can also wear protection layers by means of chemical or galvanic deposition, in particular of nickel or chrome after the final annealing. For special applications, the material of the soft magnetic Workpiece core before the final annealing also cold formed become.

The The invention will now be described with reference to a flow chart and with reference to a Sketch of a corresponding workpiece explained in more detail.

1 shows a schematic diagram of an electromagnetically actuated valve;

2 shows a flowchart with manufacturing steps for a workpiece with soft magnetic workpiece core.

1 shows a schematic sketch of an electromagnetically operable valve with a workpiece 10 made of a soft magnetic material 7 in a fuel injection assembly 8th , The workpiece 10 here forms the anchor 9 of the solenoid valve, the two positions, namely a first position 124 and a second position 125 , can take, depending on the excitation by a power source 123 that with a coil 122 interacts and a reversal of the soft magnetic material 7 of the workpiece 10 causing, so that the workpiece 10 with the surface area 3 a face 14 to the face 15 a return part 11 in the direction of arrow A strikes while a media channel 127 opens, leaving a media stream 126 in the direction of arrow B a valve seat 128 can happen.

The particularly wear-prone surface areas 1 . 2 and 3 are with a wear protection layer 4 Mistake. Here is the surface area 1 at the valve tip 12 arranged while the surface areas 2 have annular wear protection rings, which the lateral surface 13 of the anchor 9 protect against wear during high-frequency sliding movements. The wear protection layers 4 on the surface areas 3 protect the geometry of the faces 14 and 15 when they collide. Through this wear protection Schich th 4 it is ensured that the contours of the wear protection layers 4 protected surface areas 1 . 2 and 3 remain stable and do not change.

For this purpose, the soft magnetic material 7 after a final soft annealing annealed with appropriate surface hardening and protective coatings. As 1 shows, only highly stressed surface areas 1 . 2 and 3 accordingly with a wear protection layer 4 provided and not the entire surface of the workpiece core 5 , In this case, forms the soft magnetic material 7 a magnetic core 121 which in a first embodiment consists essentially of 16.45 wt .-% cobalt, 2.05 wt .-% chromium, 0.05 wt .-% manganese, 0.44 wt .-% silicon, 0.17 wt. -% aluminum, 0.0012 wt .-% oxygen, 0.028 wt .-% sulfur and the balance is iron. In a further embodiment, the soft magnetic workpiece core 5 essentially 9.25 wt.% cobalt, 13.20 wt.% chromium, 0.08 wt.% manganese, 0.027 wt.% aluminum, 0.043 wt.% sulfur, 0.01 and the balance made of iron.

In other embodiments, the fuel injection assembly 8th used as an injection valve for gasoline engines or for diesel engines or as a direct injection valve for corresponding engines.

2 shows a flowchart with manufacturing steps for in 1 shown workpiece 10 with soft magnetic workpiece core 5 , In order to produce the soft magnetic core, a corresponding one of the above-mentioned alloys can be fused by various methods. In theory, all common techniques are possible, such as melting in air or by means of VIM (vacuum induction melting). For this purpose, for example, an electric arc furnace or inductive techniques can be used. Treatment with VOD (vacuum oxygen decarburization) or AOD (argon oxygen decarburization) or ESU (electroslag remelting) improves the quality of the respective product for the workpiece core. Of these methods, however, the VIM method is preferred for the production of the alloy because it can more accurately adjust the contents of the alloying elements and better avoid non-metallic inclusions in the solidified alloy.

The melting process is followed by a different series of process steps, depending on the workpiece core to be produced. If, first of all, tapes are to be produced as semifinished products, from which the workpieces are to be punched later, the ingot resulting from the melting process is formed by pre-blocking in a slab, as is the method block 22 shows, reshaped. Under blooming, the forming of the ingot into a slab of rectangular cross-section is performed by a hot rolling process at a temperature of, for example, 1250 ° C.

After pre-blocking, the scale formed on the surface of the slab is cut through the production block by grinding 23 away. After grinding, another hot rolling process follows 24 , by which the slab is formed into a strip at a temperature of, for example, 1250 ° C. Subsequently, the impurities which form on the surface of the strip during hot rolling are removed by a further step 25 removed by grinding or pickling.

The strip is then cold-rolled at the production block 26 reshaped to the final thickness. This thickness d is in the range between 0.1 mm ≦ d ≦ 2 mm. Finally, the tape becomes a workpiece, for example by punching, with the production block 27 completed and then a final annealing in the production block 28 subjected. During the final glow 28 The lattice defects resulting from the forming processes heal and crystalline grains are formed in the structure. Finally, then the surface areas that are subject to the final workpiece high wear with a wear protection layer in the process block 29 be coated.

Similarly, the manufacturing process, when rotating parts, such as armature of a solenoid valve, are produced. Again, after melting 21 by billet ing a billet billet in a square cross section with the manufacturing block 30 prepared. The so-called pre-blocking can be carried out at a temperature of 1250 ° C. Subsequently, the scale formed in the pre-blocking with the production block 31 removed by grinding.

Thereafter, the billet is hot rolled into a wire or rods with the production block 32 up to a diameter of the wire or rods of about 13 mm. By straightening and peeling are then in the production block 33 Correcting distortions of the material and removing the impurities forming during the rolling process from the surface. Finally, a completion of the workpiece 10 with the manufacturing step 34 , wherein only the soft magnetic workpiece core is available after this manufacturing step. Finally, the workpieces are a final annealing with the step 35 Finally, on the surface areas which are highly loaded by impact or sliding movements, a wear protection layer with the manufacturing block 36 applied.

The Final annealing can be done in a temperature range of 700 ° C be carried out to 1200 ° C. In a preferred Implementation is the final annealing in the temperature range from 750 ° C to 850 ° C performed. The Final annealing can be carried out under inert gas, hydrogen or vacuum be carried out, or it can be done simultaneously in one Abscheideatmosphäre for a wear protection layer the Make a wear protection layer on uncovered Surface areas that are heavily loaded with the final annealing be connected in an advantageous Wei se. It is also possible before final annealing during workpiece production To profile workpiece by a cold deformation.

1

surface area

2

surface area

3

surface area

4

Wear protection layer

5

Workpiece core

7

soft magnetic material

8th

Fuel injection arrangement

9

anchor

10

workpiece

11

Return part

12

valve tip

13

lateral surface

14

face

15

face

21

merger

22

slabs Education

23

grind

24

Strip hot rolling

25

grind and / or pickling

26

cold rolling

27

Workpiece production

28

final annealing

29

coating

30

stick Education

31

grind

32

hot rolling of rods or wire

33

judge and peeling

34

Workpiece production

35

final annealing

36

coating

121

magnetic core

122

Kitchen sink

123

power source

124

first Position of the magnetic core

125

second Position of the magnetic core

126

media stream

127

media channel

128

valve seat

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• EP 0683862 B1 [0002]
• - DE 4421937 C1 [0003]

Claims (61)

Workpiece made of soft magnetic material comprising: - a surface area ( 1 . 2 . 3 ), which has a wear protection layer ( 4 ) having; - a workpiece core ( 5 ), the soft magnetic material ( 7 ) having; characterized in that the soft magnetic workpiece core ( 5 ) has a crystalline FeCo alloy. Workpiece according to claim 1, wherein the wear protection layer ( 4 ) Has chromium. A workpiece according to claim 1 or claim 2, wherein the wear protection layer ( 4 ) Has nickel. Workpiece according to one of the preceding claims, wherein the wear protection layer ( 4 ) has a nitrogen-containing compound. Workpiece according to one of the preceding claims, wherein the wear protection layer ( 4 ) has a carbonaceous compound. Workpiece according to one of the preceding claims, wherein the wear protection layer ( 4 ) has a carbon- and nitrogen-containing compound. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the FeCo crystalline alloy has a material having a composition consisting essentially of iron and 10% by weight ≦ Co ≦ 22% by weight, 0% by weight ≦ V ≦ 4% by weight, 1 , 5 wt% ≤ Cr ≤ 5 wt%, 0 wt% ≤ Mn ≤ 2 wt%, 0 wt% ≤ Mo ≤ 1 wt%, 0.5 wt% ≦ Si ≦ 1.5 wt%, 0.1 wt% ≦ Al ≦ 1.0 wt%, wherein the content of the elements is chromium and manganese and molybdenum and aluminum and silicon and vanadium are 4.0 Wt% ≤ (Cr + Mn + Mo + Al + Si + V) ≤ 9.0 wt%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a cobalt content of 14 wt .-% ≤ Co ≤ 22 wt .-%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a cobalt content of 14 wt .-% ≤ Co ≤ 20 wt .-%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a vanadium content of 0 wt .-% ≤ V ≤ 2 wt .-%. Workpiece according to one of the preceding claims, wherein the soft magnetic workpiece core on the base the crystalline FeCo alloy has a molybdenum content of 0.5 wt% ≤ Mo ≤ 1.0 wt%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the FeCo crystalline alloy has a molybdenum content of 0.001 wt% ≦ Mo ≦ 0.1 wt%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a manganese content of 1.25 wt .-% ≤ Mn ≤ 1.5 wt .-%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a silicon content of 0.5 wt .-% ≤ Si ≤ 1.0 wt .-%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) has a content of aluminum and silicon of 0.6 wt .-% ≤ Al + Si ≤ 2 wt .-% based on the crystalline FeCo alloy. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the FeCo crystalline alloy has a content of chromium and manganese and molybdenum and aluminum and silicon and vanadium of 6.0% by weight ≦ Cr + Mn + Mo + Al + Si + V ≦ 9.0 parts by weight % having. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy, a content of 0 wt .-% ≤ V ≤ 0.01 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% is 14 wt% ≤ Co ≤ 22. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy, a content of 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% 14 wt% ≤ Co ≤ 22. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a content of 0.75% by weight ≦ V ≦ 2.75% by weight, 2.3% by weight ≦ Cr ≦ 3.5% by weight, 1, 25 wt .-% ≤ Mn ≤ 1.5 wt .-%, 0 wt .-% ≤ Mo ≤ 0.01 wt .-%, 0.6 wt .-% ≤ Si ≤ 0.9 wt .-% and 0.7 wt% ≤ Al ≤ 1.0 wt% 14 wt% ≤ Co ≤ 22. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) in a final annealed state in the tensile test has an elongation at break A _L > 20% and a constriction Z> 50%. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) based on the crystalline FeCo alloy has a yield strength R _p0.2 > 340 MPa and a cobalt content of 14 wt .-% ≤ Co ≤ 22. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) has a coercive force H _c <3.5 A / cm on the basis of the crystalline FeCo alloy. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) has a coercive force H <2.0 A / cm on the basis of the crystalline FeCo alloy. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) has a maximum permeability μ _max > 1000 on the basis of the crystalline FeCo alloy. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) has a maximum permeability μ _max > 2000 based on the crystalline FeCo alloy. Workpiece according to one of the preceding claims, wherein the soft-magnetic workpiece core ( 5 ) has a corrosion resistant FeCoCr alloy based on the crystalline FeCo. The workpiece according to claim 26, wherein the soft magnetic workpiece core ( 5 ) comprises a material having a composition consisting essentially of iron and 3% <Co <20%, 6% <Cr <16%, 0% ≤ S ≤ 0.5%, 0% ≤ Mo ≤ 3%, 0% ≤ Si ≦ 3.5%, 0% ≦ Al ≦ 4.5%, 0% ≦ Mn ≦ 4.5%, 0% ≦ Me ≦ 6%, where Me is one or more of the elements Sn, Zn, W, Ta, Nb, Zr and Ti, 0% ≦ V ≦ 4.5%, 0% Ni ≦ 5%, 0% ≦ C <0.05%, 0% ≦ Cu <1%, 0% ≦ P <0.1% , 0% ≤ N <0.5%, 0% ≤ 0 <0.05%, 0% <B <0.01% and has the usual impurities. A workpiece according to claim 26 or claim 27, wherein the soft magnetic workpiece core ( 5 ) Has 6% <Co <15%. Workpiece according to one of claims 26 to 28, wherein the soft magnetic workpiece core ( 5 ) 0 wt% ≤ Mo ≤ 1 wt%. Workpiece according to one of claims 26 to 28, wherein the soft magnetic workpiece core ( 5 ) 1 wt% ≤ Mo ≤ 2 wt%. Workpiece according to one of claims 26 to 30, wherein the soft magnetic workpiece core ( 5 ) 0.01% ≤ Mn ≤ 1% and 0.005% ≤ S ≤ 0.5%. The workpiece according to claim 31, wherein the ratio Mn / S ≥ 1.7. The workpiece according to claim 27, wherein the sum of Cr and Mo is 11% ≤ Cr + Mo ≤ 19%. The workpiece according to claim 27, wherein the sum is Si + 1.3Al + 1.3Mn + 1.7Sn + 1.7Zn + 1.3V ≤ 3.5%. Workpiece according to one of claims 26 to 34, wherein the polarization J of the workpiece core ( 5 ) at a magnetic field H of 160 A / cm is greater than 1.6 T. Workpiece according to one of claims 26 to 34, wherein the saturation polarization J _{s of} the workpiece core ( 5 ) at a magnetic field H of 160 A / cm is greater than 1.7 T. Workpiece according to one of claims 26 to 34, wherein the saturation polarization J _{s of} the workpiece core ( 5 ) at a magnetic field H of 600 A / cm is greater than 1.75 T. Workpiece according to one of claims 26 to 34, wherein the saturation polarization J _{s of} the workpiece core ( 5 ) at a magnetic field H of 600 A / cm is greater than 1.8 T. Workpiece according to one of the preceding claims, wherein the specific electrical resistance of the workpiece core ( 5 ) is greater than 0.4 μΩm. Workpiece according to one of the preceding claims, wherein the specific electrical resistance of the workpiece core ( 5 ) is greater than 0.5 μΩm. Workpiece according to one of the preceding claims, wherein the specific electrical resistance of the workpiece core ( 5 ) is greater than 0.58 μΩm. Workpiece according to one of the preceding claims, wherein the workpiece ( 10 ) in a force fuel injection arrangement ( 8th ) and suitable for use in a gasoline engine. Workpiece according to one of claims 1 to 41, wherein the workpiece ( 10 ) in a fuel injection assembly ( 8th ) and suitable for use in a diesel engine. Workpiece ( 10 ) according to one of the preceding claims, wherein the workpiece is a component of a fuel direct injection valve of a fuel injection arrangement ( 8th ). Workpiece according to one of the preceding claims, the workpiece being for an electromagnetic Actuator is provided. Workpiece ( 10 ) according to one of the preceding claims, wherein the workpiece is provided for an armature of an electromagnetically actuated valve. Workpiece ( 10 ) according to one of the preceding claims, wherein the workpiece is provided for a return part of a solenoid valve. Workpiece ( 10 ) according to one of the preceding claims, wherein the workpiece is suitable for use in an environment comprising a mixture of fuel and alcohol, wherein the fuel comprises gasoline or diesel. Workpiece ( 10 ) according to claim 26, wherein the alcohol is one of methanol, ethanol and a mixture of methanol and ethanol. Workpiece ( 10 ) according to claim 26, wherein the mixture comprises 85% gasoline and 15% alcohol. Workpiece ( 10 ) according to claim 26, wherein the mixture comprises 80% gasoline and 20% alcohol. Method for producing a workpiece ( 10 ) of a crystalline cobalt-iron alloy, in which, by melting and hot working, first a work core made of a soft magnetic alloy is prepared, which is essentially iron and 10% by weight ≦ Co ≦ 22% by weight, 0% by weight ≤ V ≤ 4 wt%, 1.5 wt% ≤ Cr ≤ 5 wt%, 0 wt% ≤ Mn ≤ 2 wt%, 0 wt% ≤ Mo ≤ 1 wt% -%, 0.5 wt .-% ≤ Si ≤ 1.5 wt .-%, 0.1 wt .-% ≤ Al ≤ 1.0 wt .-%, wherein after or during a final annealing to a surface area of the workpiece core ( 5 ) a wear protection layer ( 4 ) is applied. The method of claim 52, wherein the final annealing at a temperature T between 700 ° C ≤ T ≤ 1100 ° C is carried out. The method of claim 52, wherein the final annealing at a temperature range T between 750 ° C ≤ T ≤ 850 ° C is carried out. The method of claim 52, wherein the final annealing is performed such that the material of the workpiece core ( 5 ) after the final annealing has deformation parameters in the tensile test of an elongation at break of A _L > 2%. The method of claim 52, wherein the final annealing is performed such that the material of the workpiece core ( 5 ) after the final annealing has deformation parameters in the tensile test of an elongation at break of A _L > 20%. Method according to one of claims 52 to 56, wherein the material of the workpiece core ( 5 ) is cold worked before the final annealing. Method according to one of claims 52 to 57, wherein the final annealing of the material of the workpiece core ( 5 ) under inert gas, hydrogen or vacuum. Method according to one of claims 52 to 57, wherein the wear protection layer ( 4 ) is applied by vapor deposition of a nickel or chromium-containing alloy. Method according to one of claims 52 to 57, wherein the wear protection layer ( 4 ) is applied by plasma nitriding, gas nitriding or nitrocarburizing. Method according to one of claims 52 to 57, wherein the wear protection layer ( 4 ) is applied by chemical or galvanic deposition after the final annealing.