DE102018208283A1 - Method for producing a metallic component - Google Patents

Abstract

A method (10) is provided for producing at least one metallic component (11), wherein first the component (11) is case hardened, wherein at least one heat treatment (13 "') for tempering the component (11) takes place, that after the heat treatment (13 "') the component (11) is reworked in order to bring the component (11) to a required final dimension within predetermined tolerances, and that thereafter the post-processed component (11) is nitrided, wherein a nitriding process (15) provided process temperature The starting temperature set for the nitriding is selected to be at least about 30 ° C., preferably at least about 50 ° C, lower than the tempering temperature.

Description

The invention relates to a method for producing a metallic component and further to a component produced by such a method.

State of the art

The standard in martensitic or bainitic hardening or case hardening of steel formed components used for heat treatment applications, which are usually formed from separate process steps of carburizing, hardening and tempering, lead to distortion in the structure of the components, so that subsequent reworking is required so that a typical for the components in the micrometer range dimensional and dimensional tolerance can be met. In this post-processing, however, the surface areas achieved by hardening or case-hardening and thus provided with positive component properties are partially or completely removed; in the former case, this is done, for example, by grinding to meet manufacturing tolerances, or by means of electrochemical rounding typically of Bohrungsverschneidungen, and in the latter case by eroding or laser ablation, for example, to accurately form holes or injection holes in nozzle bodies for diesel injection systems. In this case exposed component regions with low strength can lead to component failure in later component operation due to static or dynamic stresses acting on the component.

Additional measures taken in the manufacturing process to increase strength, such as Deep rolling, auto-rescue or shot blasting, however, has the disadvantage that they are usually implemented only to a limited extent, but at least relatively expensive and thus cost-increasing. In order to be able to withstand the operating pressures of several 1000 bar required in autofrettage, a component to be machined must have sufficient wall thickness; Even when deep rolling and blasting a minimum wall thickness of the component to be machined is required, with relatively small or complex component geometries, such as injection holes or bore fillets, practically can not be processed. Although with such or similar methods in marginal areas of a machined component per se advantageous compressive residual stresses are introduced, which counteract a static or dynamic stress in the later component operation, however, such compressive residual stresses can significantly reduce again, when in component operation relatively high temperatures, e.g. above 300 ° C, act.

A different state of the art is from the DE 197 52 051 C1 known. This is a process for producing dimensionally accurate molded parts with a nitrided or nitrocarburized surface layer. Post-processing of the nitrided or nitrocarburized molded part on receipt of the complete nitrided or nitrocarburised surface layer can then be dispensed with if it is provided that the prefabricated molded parts are hardened and tempered contrary to normal practice only at a temperature of 200 ° C. to 300 ° C., that the cured and tempered moldings are then brought to the required finished dimension by post-processing and that the post-processed moldings are nitrided or nitrocarburized. In this prior art, however, only a quenching with unusually low tempering temperature of the component is provided before the subsequent nitriding or nitrocarburizing. As a result, the volume change during nitriding compensates for the change in volume during starting.

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Advantages of the invention

The method with the features of claim 1 has the advantage that it allows a cost-effective production of heavy-duty components with the highest demands on positional and form tolerances, the hard or post processing cost is cost-reducing incurred only once and indeed in the middle of the process chain and at the same time a high mechanical strength of the components can be achieved. For this purpose, it is provided that first the component is case hardened, then at least a one-stage tempering of the component, a component post-processing to bring the component within predetermined tolerances to a required final size, and a nitriding of the component are performed sequentially, one for nitriding provided process temperature is significantly lower than a set in the post-processing upstream and used to start the component heat treatment treatment temperature is selected. In contrast to the prior art according to DE 197 52 051 C1 According to which only a hardening of the component takes place - in contrast to case hardening in the invention - wherein the tempering temperature after curing in a relatively low temperature range and also far below the Nitrierprozesstemperatur, on the other hand, the different underlying idea of the invention is both a carburizing , hardening as well as tempering to perform extensive case hardening, and the tempering temperature and the nitriding process temperature to each other agree that during nitriding strength-enhancing properties such as residual compressive stresses are formed, whereby a high mechanical strength of the component can be achieved, and at the same time an additional post-processing step cost-reducing unnecessary or savings, which is achieved in that the nitriding at a significantly lower process temperature than that tempering temperature applied during annealing, thereby avoiding distortion in the component structure during nitriding.

Further advantageous developments and refinements of the invention will become apparent from the measures listed in the dependent claims.

A preferred embodiment of the method according to the invention provides that the process temperature selected for nitriding the component is at least about 30 ° C., preferably about 50 ° C., lower than the tempering temperature. The present inventors conducted experimental studies have shown that a process temperature difference T _A - T _P of about 30 ° C between Nitrierprozesstemperatur T _P and the previously effected tempering heat treatment temperature T _A represents a minimum distance, at which respect a delay in the component structure by the nitriding is avoidable and thus the dimensional and dimensional stability is maintained during the nitriding, so that there is no need for a one- or multi-stage post-processing after nitriding.

In this case, the step of case hardening comprises a tempering process, which in the temperature range between about 450 ° C and 550 ° C, preferably at about 500 ° C, performed, since only from a temperature which is higher than 450 ° C, at the end the nitride forming the process chain and adapted to the annealing process, a formation of special nitrides such as of chromium nitride in the structure of a component. Higher temperatures than 550 ° C, however, are less suitable, since the core strength is greatly reduced especially in low-alloyed steels and thus the component functionality is limited.

An embodiment variant of the invention may be that at least one nitriding phase is carried out for nitriding the component in order to form a diffusion layer enriched mainly with nitrogen, which is advantageous in particular for cyclic loading of the component to ensure high wear resistance and fatigue strength.

According to a preferred embodiment of the invention, nitriding phases are separated by an intermediate gas exchange phase, wherein a first nitriding phase is formed as oxinitriding, whereby the surface activity of the component to be processed and thus the nitrogen uptake is significantly improved, while the second nitration phase is used for pure nitriding of the component preconditioned by the oxinitriding, wherein in pure nitriding the main thickness of a nitriding layer or diffusion layer is formed. In this case, the two nitration phases can be carried out with differently sized durations, on the one hand tune the Oxinitrierdauer - to activate passivated component surfaces - on the surface properties of the starting material used and on the other hand to be able to adjust the duration of the downstream pure nitriding depending on the desired thickness of the trainees diffusion layer. With the intermediate gas exchange phase, the Oxinitrieren characterizing process gas mixture is removed to set defined initial conditions for the subsequent second Nitrierphase.

Expediently, the nitride layer or diffusion layer is formed in the surface region of the component with a thickness which lies in the range of approximately 5 to 50 μm, since even with such nitriding layer thicknesses, a significant increase in the vibration resistance relative to the base material can be achieved. Thicker nitriding layers can also be formed, but correspondingly longer nitriding process runtimes are required.

A modified embodiment of the invention can consist in that the component is additionally subjected to a nitrocarburizing phase after the at least one nitriding phase in order to form a bonding layer on the component. The formation of such a connection layer over a diffusion layer produced on the basis of the previously performed nitriding phase is particularly advantageous if the component is subject to not only wear but also corrosive stresses during later use.

The term nitriding is to be understood as meaning a process in which a nitrogen and / or carbon-releasing medium introduces nitrogen and / or carbon into a component with the aim of producing precipitates such as e.g. Form nitrides or carbonitrides. Accordingly, the term nitriding also includes nitrocarburizing.

A further modified embodiment of the invention may be that the component is nitrided by means of a Nitrocarburierphase, which leads exclusively to the formation of a compound layer formed from iron nitrides, due to their ceramic character and high Hardness counteracts stresses caused by friction.

The supply of process gases and / or process gas mixtures in a suitable for carrying out the method according to the invention treatment or process chamber takes place during the process with amounts of solid gas. Alternatively, the supply may also be characteristic-controlled, for example by nitriding characteristic and / or oxidation index and / or coefficient of coal.

A manufactured according to such a method component, in particular a nozzle body, depending on the process control can have a high fatigue strength and / or improved wear and corrosion resistance and is suitable for example for use as a component in high pressure injection systems.

list of figures

• 1 ein Schema zur groben Veranschaulichung des erfindungsgemäßen Verfahrens zum Herstellen eines Bauteils, wobei im unteren Teil des Schemas entlang der Ordinate die Prozess-Temperatur in Abhängigkeit von der entlang der Abszisse aufgetragenen Zeit dargestellt ist und im oberen Teil des Schemas das Bauteil jeweils in seinen verschiedenen Prozessstadien eingezeichnet ist,
• 2A ein Diagramm, das die Abfolge aufeinanderfolgender Verfahrensschritte in Abhängigkeit von der jeweils einzustellenden Prozess-Temperatur gemäß einer ersten Ausführungsform darstellt,
• 2B ein Diagramm, das die Abfolge aufeinanderfolgender Verfahrensschritte in Abhängigkeit der jeweils einzustellenden Prozesstemperatur gemäß einer zweiten Ausführungsform darstellt,
• 2C ein Diagramm zur Darstellung der Abfolge aufeinanderfolgender Verfahrensschritte in Abhängigkeit der jeweils einzustellenden Prozesstemperatur gemäß einer dritten Ausführungsform,
• 2D ein Diagramm zur Darstellung der Abfolge aufeinanderfolgender Verfahrensschritte in Abhängigkeit der jeweils einzustellenden Prozesstemperatur gemäß einer vierten Ausführungsform,
• 3 ein Messdiagramm mit anhand von GDOES-Messungen an zwei unterschiedlich prozessierten Proben ermittelten drei Messkurven, wobei zwei der Messkurven die jeweiligen Kohlenstoff-Konzentrationsverläufe der beiden Proben und die dritte Messkurve den Stickstoff-Konzentrationsverlauf in der zweiten Probe in funktionaler Abhängigkeit vom Randabstand zur Probenoberfläche darstellen,
• 4A eine mikroskopisch erstellte Schnittansicht eines Gefüges eines gemäß dem erfindungsgemäßen Verfahren hergestellten Düsenkörpers im Bereich einer Spritzlochbohrung, und
• 4B ein Diagramm zur Darstellung des Härteverlaufs im Gefüge des Düsenkörpers von 4A im Bereich einer Spritzlochbohrung, wobei auf der Ordinate die Vickershärte in Abhängigkeit von dem entlang der Abszisse aufgetragenen Randabstand bezüglich der Oberfläche der Spritzlochbohrung dargestellt ist.

Embodiments of the invention are explained in more detail in the following description and in the accompanying drawings. The latter show in schematic views:

• 1 a schematic for a rough illustration of the method according to the invention for producing a component, wherein in the lower part of the scheme along the ordinate, the process temperature is shown in dependence on the time plotted along the abscissa and in the upper part of the scheme, the component in each of its various stages of the process is drawn,
• 2A a diagram illustrating the sequence of successive process steps as a function of the respective set process temperature according to a first embodiment,
• 2 B a diagram illustrating the sequence of successive process steps as a function of the process temperature to be set in each case according to a second embodiment,
• 2C 3 shows a diagram for illustrating the sequence of successive method steps as a function of the process temperature to be respectively set according to a third embodiment,
• 2D a diagram for illustrating the sequence of successive method steps as a function of the process temperature to be set in each case according to a fourth embodiment,
• 3 a measurement diagram with three measured curves determined by GDOES measurements on two differently processed samples, wherein two of the measurement curves represent the respective carbon concentration curves of the two samples and the third measurement curve the nitrogen concentration curve in the second sample in functional dependence on the edge distance to the sample surface,
• 4A a microscopic sectional view of a structure of a nozzle body produced according to the method according to the invention in the region of a spray hole, and
• 4B a diagram showing the hardness profile in the structure of the nozzle body of 4A in the region of a spray hole, the Vickers hardness being shown on the ordinate as a function of the edge distance along the abscissa with respect to the surface of the injection hole.

Embodiments of the invention

1 illustrates very schematically the essential process steps of a generally designated 10 method, which is used to produce a metal-formed component 11 serves, which in the exemplary embodiment as a substantially rotationally symmetrical nozzle body made of steel with a blind bore extending along the rotation axis of symmetry 11 ' is trained. After a first stage of the process 12 , in which the soft machining of the component 11 is carried out in a subsequent second process stage 13 the case hardening of the component 11 case hardening is carburizing 13 ' at a temperature T ₁ , the hardening 13 " at a temperature T ₀ and the tempering 13 '' at a temperature T ₂ includes. After that, the component points 11 a case hardening layer 11 " in the near-surface area. This is followed by a third stage of the process 14 the post-processing of the component 11 to the inevitably occurring during case hardening warping of the component 11 with the case hardening layer 11 " partially, ie for example in the plane surface area 11 - 2 is removed by chip removal until a predetermined geometric tolerance in the micrometer range is achieved. In addition, the component becomes 11 during post-processing with holes 11 - 1 provided, which are also designed to tolerate tolerances in terms of their positional tolerance and alignment in the micrometer range. Thereafter, the thus reworked component 11 in a fourth stage of the process 15 subjected to a nitriding process. The treatment temperature or process temperature is thereby T ₃ adjusted so that T ₃ at least 30 ° C below the tempering temperature T ₂ lies to a recurring distortion of the component 11 to avoid. Due to the nitriding process arises on the component 11 especially in the edge region of the holes 11 - 1 a nitriding layer 11 '" , With which a higher strength and / or fatigue strength and / or wear resistance of the component can be achieved. After the nitriding process 15 is the component 11 ready for assembly 16 ,

2A shows the temporally successive process phases of the nitriding process 15 based on a diagram, with the respective process temperature T is plotted against the time axis t for the individual process phases and the individual process phases are defined with their respective time duration along the time axis. The nitriding process 15 comprises in succession a first heating phase 20 a temperature equalization phase 21 , a pre-oxidation phase 22 , a first gas exchange phase 23 , a second heating phase 24 , a second temperature equalization phase 25 , a first nitriding phase 26 ' , a second gas exchange phase 27 , a second nitriding phase 26 " , a third gas exchange phase 29 and a cooling phase 30 , In the first heating phase 20 the temperature is continuously increased at a constant heating rate up to a treatment temperature of about 400 ° C. When the treatment temperature is reached, the temperature equalization phase closes 21 in which the treatment temperature is kept constant at about 400 ° C. Both during the heating phase 20 as well as during the temperature equalization phase 21 No supply of nitrogen donor gas takes place in the treatment chamber (not shown) for carrying out the method. In the on the temperature equalization phase 21 following pre-oxidation phase 22 , Which takes place at 400 ° C, is for pre-oxidation of the produced component of the treatment chamber, a process gas, such as air or water vapor or mixtures thereof or with nitrogen-enriched mixtures of air and water vapor, with a pressure of several 100 mbar, preferably with an absolute pressure in the range between about 200 and 400 mbar or with a relative to atmospheric pressure increased to several tens of mbar, preferably about 20 to 50 mbar supplied. Following the pre-oxidation phase 22 is carried out at constant temperature, the first gas exchange phase 23 to remove the oxidizing process gas atmosphere from the treatment chamber. This can be done for example by evacuation by means of vacuum pumps below a process gas pressure p <1 × 10 ^-1 mbar, preferably at p <1 × 10 ^-2 mbar, or by flushing with an inert gas such as nitrogen or argon. The following second heating phase 24 serves to continuously increase the temperature at a constant rate of heating up to a process temperature of about 490 ° C. Upon reaching the process temperature of about 490 ° C is in the subsequent temperature equalization phase 25 the process temperature reached kept constant. In the following first nitration phase 26 ' which is carried out at the process temperature kept constant at about 490 ° C for a predetermined period of time Δt ₁ , the process chamber is supplied with a nitrogen-emitting process gas formed of, for example, ammonia or mixtures of ammonia, nitrogen and / or hydrogen; the process gas can be used to intensify the nitriding process 26 ' also oxidizing components, which may be formed, for example, from air or water vapor or nitrous oxide. After the first nitration phase 26 ' the gas exchange phase takes place 27 which serves that during the nitriding phase 26 ' set process gas composition controlled from the treatment chamber to remove, for example by evacuation by means of vacuum pumps below a process gas pressure p <1 × 10 ^-1 mbar, preferably at p <1 × 10 ^-2 mbar, or by purging with an inert gas such as nitrogen or argon. This is followed by the second nitriding phase 26 " at the constant held process temperature of about 490 ° C, that is isothermal with respect to the first Nitrierphase 26 ' , performed for a predetermined period of time Δt ₂ . The subsequent gas exchange phase 29 This is used during the second nitriding phase 26 " set process gas composition - as in the phase 26 ' - controlled to remove from the treatment chamber; In addition, an undesirable, caused by temperature differences, inhomogeneous nitriding on the component still in the process during the cooling phase is avoided. In the final cooling phase 30 the component is cooled to room temperature. The for the two nitration phases 26 ' . 26 " isothermally set process temperature T ₃ becomes dependent on the tempering temperature T ₂ so chosen or adjusted that the process temperature T ₃ about 30 ° C lower than the tempering temperature T ₂ lies; because the intended during case hardening tempering T ₂ In this embodiment, T ₂ = 520 ° C, accordingly, the process temperature T ₃ for the two nitriding phases 26 ' . 26 " on T ₃ = 490 ° C.

A minor modification of the embodiment according to 2A is that the tempering is carried out at a tempering temperature of T ₂ = 500 ° C and depending on the two Nitrierphasen 26 ' . 26 " maintained process temperature T ₃ = 470 ° C is set to maintain a temperature difference of 30 ° C between the annealing process and the nitriding. This is the first nitriding 26 ' formed as Oxinitrieren in a process atmosphere of ammonia, nitrogen and air to eliminate any passivated surfaces of the starting material, while the second Nitrierphase 26 " is formed as an actual nitration process in a process atmosphere of ammonia and nitrogen, wherein the time periods Δt ₁ and Δt ₂ can be dimensioned differently. Reproducible results are through Activation of the component surface achievable by the time period .DELTA.t _{1 of} the first phase 26 ' is chosen so that Δt ₁ ≥ 1 h applies.

2 B shows a second embodiment of the method according to the invention, which differs from the first embodiment in that in addition to the two nitriding phases 26 ' . 26 " another downstream nitrocarburizing phase 26 '' with a duration Δt ₃ is carried out. In this case takes place between the second Nitrierphase 26 " and the downstream nitrocarburizing phase 26 '' a gas exchange phase 29 to defined starting conditions for the Nitrocarburierphase 26 '' and directly after the nitrocarburizing phase 26 "' becomes a gas exchange phase 29 ' downstream, which as a defined transition to the final cooling phase 30 serves. The nitrocarburizing phase 26 '' is advantageously isothermal with respect to the temporally upstream Nitrierphasen 26 ' . 26 " performed, as this can save an intermediate heating step. In the nitrocarburizing phase 26 '' the process chamber is fed to a nitrogen and carbon-emitting process gas, which may be formed, for example, from ammonia enriched with CO ₂ , CO or acetylene. In this case, the process gas composition is substantially free of oxidizing components, such as air or water vapor, in order to avoid the formation of undesirable oxide layers in the surface edge region of the component to be processed. With the following after the nitriding phases 26 ' . 26 " carried Nitrocarburierphase 26 "' For example, in addition to a nitriding layer formed during nitriding, a connecting layer is formed or an already formed connecting layer is further reinforced, which is particularly advantageous, for example, when the component surfaces are substantially subject to wear due to frictional wear during subsequent use.

2C shows a third embodiment of the method according to the invention, which in contrast to the two embodiments according to 2A and 2C only a single nitration phase 26 having a time duration Δt, which after the gas exchange phase following the second heating phase 25 is carried out, wherein after the end of the single nitration phase 26 a gas exchange phase 29 takes place as a defined transition to the final cooling phase 30 serves. This embodiment is particularly advantageous if the starting material is a steel grade in which, due to material-specific properties, there is no tendency to form passivating surfaces, so that an oxinitriding phase -as in the embodiment according to FIG 2A - Is dispensed as activating or conditioning precursor for the actual nitration process.

2D shows a fourth embodiment of the method according to the invention, which is a modification of the third embodiment of 2C and in contrast instead of the nitration phase 26 a nitrocarburizing phase 26 '' is performed with a time duration Δt '. In the nitrocarburizing phase 26 '' the supply of a nitrogen and / or carbon-emitting process gas, which comprises, for example, ammonia or mixtures which may have ammonia diluted with nitrogen and / or hydrogen and are enriched with carbon dioxide or carbon monoxide or acetylene or mixtures thereof. In this case, the process gas composition is virtually free of oxidizing components, such as air or water vapor, in order to avoid the formation of an undesirable oxide layer in the surface edge region of the processed component. In the nitrocarburizing phase 26 '' Only the formation of a connecting layer formed from iron nitrides, which is particularly advantageous if the component is subject to a frictional stress and / or corrosion stress in later use.

All embodiments have in common that the process gases or process gas mixtures of the treatment chamber can be supplied as a fixed gas quantities; Alternatively, their supply can also nitrierkenn- and / or oxidation and / or kohlkennzahlgeregelt done.

3 shows a measurement diagram with three measurement curves 40 . 41 . 42 of measurements made by means of GDOES ("glow discharge optical emission spectroscopy") on two differently processed samples or blanks. On the ordinate is the concentration C in percent by mass M% and on the abscissa the edge distance d in μm is plotted relative to the surface. The trace 40 represents the carbon concentration curve in a case hardened sample or blank as a depth profile while the trace 41 the carbon concentration curve in a according to the inventive method according to the embodiment 1 prepared or treated sample or Ronde represents. From the concentration curve of the measurement curve 41 It can be seen that by the both the case hardening as well as the downstream nitriding comprehensive heat treatments according to the inventive method in comparison to the measurement curve 40 practically no additional carbon in the surface layer, ie in the near-surface region was introduced, since both curves 40 . 41 have comparable concentration values in the near-surface edge area. The trace 42 indicates the nitrogen concentration course in a sample or blank prepared according to the method according to the invention, wherein the basis of the measurement curve 42 a high nitride concentration to a depth of about 50 - 60 .mu.m with respect to the surface of the sample is recognizable and thus can be derived from this nitriding a Nitrierschichtdicke of about 50 - 60 microns.

4A shows a micrograph along a section through a nozzle body produced according to the method according to the invention 50 in the area of a spray hole 51 , being on both sides 52 . 53 the injection hole 51 Hardness tests with measuring points 52 ' . 53 ' were made. The hardness tests were with HV 00:05 carried out.

4B shows a diagram in which the measuring points 52 ' . 53 ' from 4A are plotted to the hardness curve H in HV in the structure as a function of the edge distance d in microns, ie from the distance to the surface of the injection hole 51 to apply the component. The below the spray hole 51 from 4A measuring points determined on the basis of the hardness tests 52 ' are each shown in the diagram by means of a triangular shaped reference symbol, while those above the pointed hole 51 from 4A measuring points determined on the basis of the hardness tests 53 ' are each identified by means of a square shaped reference symbol. From the hardness depth profile shown in the diagram, the high hardness of the - nitrided - surface layer zone compared to the lower area of the structure is visible, because in the vicinity of the edge region of the injection hole 51 the hardness readings (about 1200 HV 0.05 to about 1400 HV 0.05) are relatively high, the hardness decreasing with increasing depth or distance from the edge; this decrease is noticeable at d> 40 μm, whereby in the range 60 μm ≤ d ≤ 80 μm an asymptotically running hardness value of about 800 HV 0.05 can be seen.

As starting material for the process according to the invention 10 for the manufacture of components 11 is heat-resistant steel from the group of case hardening steels such as 10CrMo9-10 or 13CrMo4-5, or from the group of hot working steels such as X38CrMoV5-1, X38CrMoV5-3 or X40CrMoV5-1, or from the group of stainless steels such as X10CrMoVNb9- 1 or X20CrMoV11-1.

In summary, the procedure 10 for producing at least one metallic component 11 provided, wherein first the component 11 case hardened, wherein at least one heat treatment 13 '' for starting the component 11 done that after the heat treatment 13 '' the component 11 is reworked to the component 11 to bring to a required within predetermined tolerances gauge and / or a final shape, and that thereafter the post-processed component 11 nitriding, with one for nitriding 15 provided process temperature significantly lower than one in the post-processing upstream and for starting the component 11 serving heat treatment 13 '' set tempering temperature is selected. In this case, the process temperature provided for nitriding is selected such that it is at least about 30 ° C., preferably at least about 50 ° C., lower than the tempering temperature.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 19752051 C1 [0004, 0005]

Claims (11)

Method for producing at least one metallic component, wherein first the component (11) is case-hardened, wherein at least one heat treatment (13 "') for tempering the component (11) takes place, after the heat treatment (13"') the component (11 ) is machined to bring the component (11) within a predetermined tolerances to a required final dimension, and then that the post-processed component (11) is nitrided, wherein a process temperature provided for nitriding (15) significantly lower than in the post-processing ( 14) upstream and tempering heat treatment (13 '") set tempering temperature is selected. Method according to Claim 1 characterized in that the process temperature (T ₃ ) provided for nitriding is selected to be at least about 30 ° C, preferably at least about 50 ° C, lower than the tempering temperature (T ₂ ). Method according to Claim 1 or 2 , characterized in that the case hardening comprises a tempering operation which is carried out in the temperature range between about 450 ° C and 550 ° C, preferably at about 500 ° C. Method according to one of Claims 1 to 3 , characterized in that for nitriding the component (11) at least one nitriding phase (26) is performed. Method according to one of Claims 1 to 4 , characterized in that for nitriding at least two nitriding phases (26 ', 26 ") are performed, which are separated by an intermediate gas exchange phase change (27) from each other. Method according to Claim 5 , characterized in that a first nitriding phase (26 ') is formed as Oxinitrieren, while a second Nitrierphase (26 ") is used for the actual formation of a diffusion layer as a nitriding layer. Method according to Claim 5 or 6 , characterized in that the two nitriding phases (26 ', 26 ") are carried out with differently sized periods of time. Method according to one of Claims 1 to 7 , characterized in that a nitriding layer is formed in the surface region of the component (11) with a thickness which is in the range of about 5 to 50 microns. Method according to one of Claims 1 to 8th , characterized in that after the at least one nitriding phase, the component (11) is additionally subjected to a nitrocarburizing phase (26 "') in order to form a bonding layer on the component (11). Method according to Claim 1 or 2 , characterized in that the component (11) by means of a Nitrocarburierphase (26 '") is nitrided. Component, in particular nozzle body, produced according to the method of any one of the preceding claims.

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