EP3611289A1 - Method of manufacturing hardened components for gear boxes and gear boxes - Google Patents
Method of manufacturing hardened components for gear boxes and gear boxes Download PDFInfo
- Publication number
- EP3611289A1 EP3611289A1 EP18189472.6A EP18189472A EP3611289A1 EP 3611289 A1 EP3611289 A1 EP 3611289A1 EP 18189472 A EP18189472 A EP 18189472A EP 3611289 A1 EP3611289 A1 EP 3611289A1
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- EP
- European Patent Office
- Prior art keywords
- workpiece
- protective layer
- gear
- oxide
- substance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/08—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases only one element being applied
- C23C8/10—Oxidising
- C23C8/12—Oxidising using elemental oxygen or ozone
- C23C8/14—Oxidising of ferrous surfaces
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C8/06—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases
- C23C8/28—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using gases more than one element being applied in one step
Definitions
- the invention relates to a method for producing transmission components, in which a workpiece is hardened.
- the invention also relates to a workpiece that is hardened by the corresponding method and a gear component that is made from such a workpiece.
- the invention also relates to a transmission which has at least one corresponding transmission component.
- WO 2010/097300 A1 discloses a method for coating a metallic surface with a protective layer. A nanoscale powder, a porous ceramic powder and a solvent are applied. This coating protects the metallic surface from chemical attacks in a carburizing atmosphere.
- Hardened components are used in numerous technical fields, the manufacture of which requires considerable effort. Furthermore, there is a requirement in many technical areas to provide increasingly powerful components more cost-effectively and faster. This is particularly true in the field of gear technology, in which highly stressable components are required. There is a need for a manufacturing process for hardened transmission components that is quick, reliable, cost-effective and easy to implement.
- the invention is based on the object of providing a production method which offers an improvement in at least one of the aspects outlined above.
- the task is solved by the method according to the invention, which is designed to produce a transmission component.
- the method includes hardening the workpiece, which was previously machined, for example, as part of a so-called soft machining.
- the process includes a first step in which the workpiece and a hardening furnace are provided.
- a process environment is provided by setting a process temperature in the hardening furnace.
- the workpiece is placed in the hardening furnace and heated by the process temperature there.
- a workpiece temperature is adjusted to the process temperature by heating the workpiece.
- a protective layer is produced on at least one area of a surface of the workpiece.
- the protective layer serves to minimize or avoid an undesired chemical reaction of the surface of the workpiece with the process environment, for example a so-called edge oxidation of the workpiece.
- edge oxidation of the workpiece. The more extensive an edge oxidation is formed, the greater the weakening of the machined workpiece.
- the protective layer is formed on the basis of a substance which is present as an alloy element in the workpiece.
- the protective layer lies on the surface of the workpiece, so that a base material of the workpiece is shielded from the process environment by the protective layer.
- the alloy element present in the base material is converted in the area of the surface of the workpiece into a material which forms the protective layer on the surface.
- a suitable material must be selected for the workpiece, that is to say its base material, in which the corresponding alloy element is present with an at least sufficient proportion, that is to say an at least sufficient concentration.
- the protective layer is thus automatically formed on the entire surface of the workpiece. Alloys are typically largely homogeneous, so that the protective layer is formed essentially uniformly over the entire surface of the workpiece. The fact that further handling steps, for example by a worker, are unnecessary a high degree of process reliability is achieved. Furthermore, the protective layer is thereby formed from inside the workpiece.
- the protective layer can also be formed based on a material that is present in a coating.
- the coating is applied to the workpiece when the workpiece is made available for hardening in the first step.
- a particularly suitable material for forming the protective layer can be selected by an appropriate coating depending on the process temperature and / or process environment.
- a particularly suitable substance is, for example, a substance that can be converted into a protective layer that has a high chemical inertness and thus offers an increased protective effect for the surface of the workpiece. Overall, the number of materials that can be used as the base material of the workpiece is increased for the desired gear component.
- a protective layer which is made from an alloy element in the base material of the workpiece a further increased protective effect can be achieved.
- the material for forming the protective layer can be designed to form an oxide on the surface of the workpiece when the process temperature is present.
- the oxide can also be formed at a temperature below the process temperature.
- the material for forming the protective layer can be at the process temperature in the workpiece present in the method be diffusible.
- a diffusion current of the corresponding alloy element from the interior of the workpiece on its surface is thus caused during the method.
- a sufficient amount of a starting material which is required for forming the protective layer is automatically provided on the surface with the alloy element.
- the diffusion current is also reduced when the formation of the protective layer occurs in a saturation region.
- the claimed method is thus self-regulating, which in turn allows the method to be implemented reliably and reliably.
- a process environment in the hardening furnace in which the workpiece is carburized there can be a process environment in the hardening furnace in which the workpiece is carburized.
- a process temperature at which carbon from the process environment is embedded in the surface of the workpiece thus increasing the hardness of the workpiece.
- a protective layer can also be formed in a corresponding process environment, in particular at a process temperature of 800 ° C to 1200 ° C. Edge oxidations are usually to be expected at correspondingly high process temperatures, which also allow carburizing.
- the protective layer is suitable to withstand the corresponding process temperatures and offers reliable protection against further edge oxidation.
- the alloy element in the workpiece from which the protective layer is to be formed is chromium, zirconium, titanium, nickel, zinc, aluminum, or lead.
- the oxides of these substances form a chemically inert protective layer on the surface of the workpiece, which offers a particularly high degree of protection against edge oxidation.
- chrome, zirconium, titanium, zinc and aluminum are tried and tested alloying elements for numerous types of steel.
- suitable materials for the workpiece are readily available.
- Chromium is a tried and tested substance as a material for forming a protective layer, for example in the context of a so-called chromium passivation.
- chromium is readily diffusible in the workpiece at the process temperature in the hardening furnace, which accelerates the formation of the protective layer. This further minimizes the formation of edge oxidations on the workpiece.
- the coating can be applied by alitizing, by chroming or by applying a paste.
- Aluminum can be provided by alitizing as a material that is suitable for forming a passivating protective layer, namely an aluminum oxide layer, on the surface of the workpiece.
- Chromium provides chromium, which can form a passivating chromium oxide layer.
- any substance, in particular titanium or zirconium can be provided in a paste, which is suitable for forming a passivating protective layer when the process temperature is present.
- a combination of several such substances can also be provided by a paste. The claimed method can thus be easily adapted to a large number of materials from which the workpiece can be produced.
- the protective layer which is to be produced during the third method step can have chromium oxide, aluminum oxide, zirconium oxide, titanium oxide, nickel oxide, zinc oxide and / or lead oxide. Such oxides provide an effective passivation for the workpiece on the surface.
- the second and / or third step takes place in a gas atmosphere.
- a gas atmosphere can be a so-called carburizing atmosphere, for example, which comprises gaseous carbon compounds for the incorporation of carbon in the surface of the workpiece.
- the gas atmosphere can also be designed as a protective gas atmosphere.
- the claimed process minimizes the occurrence of edge oxidations even in a gas atmosphere due to the protective layer. Complex carburizing in a vacuum can thus be replaced by the claimed method while the quality of the treated workpiece remains at least constant. This speeds up the manufacture of the gear components and at the same time maintains or increases the quality of the treated workpieces. As a result, the desired transmission components can be manufactured more cost-effectively overall.
- the workpiece can be made of a steel or a steel alloy.
- Steels or steel alloys are available in a wide range of properties and can be processed reliably, i.e. reliably.
- steel or steel alloys are suitable for serving as the base material for workpieces, on which a protective layer is to be formed which has a passivating effect.
- steel or steel alloy offers advantageous strength, which is essential for gear components.
- the third method step in which the protective layer is formed can be carried out for the duration of an adjustable process duration.
- the process duration can be selected depending on a number of sizes. In particular, the process duration is selected depending on the process temperature. The lower the process temperature, the longer it takes until a sufficient protective layer is formed by diffusion from the inside of the workpiece.
- the duration of the process can be set such that saturation occurs during the third method step when the protective layer is formed.
- the process duration can also be set depending on the material used for the workpiece and / or the coating applied.
- the process duration can also include a so-called carburizing phase, in which the formation of the protective layer is completed and only the workpiece is carburized.
- the process duration is, for example, by a Algorithm or a table adjustable in a control unit of the hardening furnace. As an alternative or in addition, the process duration can also be adjustable by user input.
- the process duration can also be set as a function of a proportion of the alloy element that is provided for forming the protective layer.
- the proportion is to be understood as the concentration of the corresponding alloying element in the material of the workpiece, for example.
- the process duration can also be selected as a function of a diffusion rate of the corresponding alloy element in the workpiece. The higher the diffusion rate of the alloy element in the workpiece, the faster the protective layer is formed. The claimed method can thus be easily adapted to the material used.
- a partial pressure of oxygen in the hardening furnace can be reduced compared to an ambient atmosphere. Accordingly, there is a reduced supply of oxygen in the hardening furnace, which further inhibits the formation of edge oxidation. This further increases the effect of the claimed method, so that the material used for the gear components can be used even more.
- a workpiece according to the invention which is suitable for the production of, for example, a gear component.
- the workpiece can also be suitable for producing a compressor blade or a turbine blade in a turbomachine.
- the workpiece is hardened and is suitable for immediate hard machining.
- the workpiece thus represents an intermediate product in the manufacture of a Gear component or a compressor or turbine blade.
- the workpiece is processed in a method according to one of the embodiments outlined above. As a result, the workpiece according to the invention has at most a minimum of edge oxidations, which reduce the strength of the workpiece.
- the workpiece according to the invention has completed the treatment by the method described above and is immediately suitable for quenching, tempering and / or heating, which is followed by hard machining. Another processing step between hardening and hard machining, such as shot peening, is unnecessary.
- the workpiece according to the invention considerably accelerates and simplifies the manufacture of a transmission component, which results in increased economy. The same advantages are also achieved in the manufacture of a compressor blade or a turbine blade of a turbomachine.
- the gear component is designed as a spur gear, ring gear, planet gear, or as a sun gear for a planetary gear or a spur gear.
- the gear component is made from a workpiece that is designed according to a method according to one of the above-described embodiments. Accordingly, the gear component is made from a workpiece as claimed above.
- the gear component has at most a minimum of edge oxidation, by means of which the strength of the gear component is reduced.
- the gear component can be dimensioned more compactly than known gear components, which are intended to be subjected to the same mechanical stresses. Accordingly, the stressed gear component offers increased material utilization and increased power density.
- the underlying task is also solved by the transmission according to the invention.
- the transmission can be designed, for example, as a planetary gear or spur gear be and has a housing in which a plurality of transmission components is excluded.
- at least one of the gear components is designed according to the solution described above, that is to say it is produced from a workpiece that is treated according to a claimed method.
- Improved material utilization is achieved by the at least one gear component, which is processed with the claimed method, which in turn allows a more compact dimensioning of the gear component.
- Such improved transmission components in turn make it possible to manufacture the transmission according to the invention more compactly.
- FIG. 1 schematically shows a first embodiment of a claimed method 100, in which a workpiece 10 is acted on.
- FIG. 1 shows a section of the workpiece 10, which is to be further processed into a transmission component 40, during a third method step 130.
- the workpiece 10 is made of a material 14 which serves as the base material 23. Due to the shape of the workpiece 10, it has a certain volume 11 overall. This in FIG. 1
- the present workpiece 10 is to be further processed into a gear component 40.
- the base material 23 from which the workpiece 10 is made is a steel alloy and has a plurality of alloy elements 14 which are shown in FIG FIG. 1 are indicated by dots.
- One of the alloy elements 14 is a substance 15, from which a protective layer 16 is to be formed on the surface 12 of the workpiece 10 in the third step 130.
- the material 15 is chrome, which is present as an alloy element 14 in the base material 23.
- the workpiece 10 is located in a hardening furnace 30 in which a gas atmosphere 20 is present.
- the gas atmosphere 20 has a gaseous carbon compound which is suitable for storing carbon 22 in the area 12 of the workpiece 10.
- a so-called carburizing is thereby realized, by means of which the hardness of the workpiece 10 after quenching is increased on its surface 12.
- a process environment 26 is defined by the gas atmosphere 20 and a present process temperature 25, under which a workpiece temperature 29 adapts to the process temperature 25.
- the material 15 present as alloying element 14 becomes diffusible to form the protective layer 16 in the base material 23.
- a diffusion 17 of the substance 15 in the direction of the surface 12 is essentially caused across the surface. This results in an accumulation of the substance 15 on the surface 12, which is exposed there to the process environment 26 is.
- the substance 15 forms an oxide 21, namely a chromium oxide.
- the oxide 21 essentially occupies the surface 12 and thus forms the protective layer 16.
- the protective layer 16 in turn has a chemically passivating effect, so that a reaction of the surface 12 with oxygen 33 in the process environment 26 is inhibited or avoided. Furthermore, the partial pressure 43 of the oxygen 33 is reduced compared to an ambient atmosphere.
- a substantially continuous protective layer 16 is produced on the surface 12 in the third step 130, only carbon 22 is stored in the surface 12, that is to say only the so-called carburizing 31.
- the third method step 130 is carried out for an adjustable process duration 32 , which is set depending on the substance 15 and the process temperature 25. The lower the substance 15 and the process temperature 25, the longer it takes until an essentially continuous protective layer 16 is formed.
- the formation of edge oxidations 19 is reduced or prevented, which reduce the strength of the workpiece 10.
- the protective layer 16 is essentially formed from the inside of the workpiece 10.
- FIG 2 schematically shows a second embodiment of a claimed method 100, in which a workpiece 10 is acted on.
- FIG 2 shows a section of the workpiece 10, which is to be further processed into a transmission component 40, during a third method step 130.
- the workpiece 10 is made of a material 14 which serves as the base material 23. Due to the shape of the workpiece 10, it has a certain volume 11 overall. This in FIG 2
- the present workpiece 10 is to be further processed into a gear component 40.
- the base material 23 from which the workpiece 10 is made is a steel alloy.
- a coating 27 is applied to the surface 12 of the workpiece 10 and has a material 15 that is suitable for forming a protective layer 16.
- the material 15 is chrome, which is added to the coating 27, which is designed as a paste.
- the workpiece 10 is located in a hardening furnace 30 in which a gas atmosphere 20 is present.
- the gas atmosphere 20 has a gaseous carbon compound which is suitable for storing carbon 22 in the area 12 of the workpiece 10.
- a so-called carburizing is thereby realized, by means of which the hardness of the workpiece 10 after quenching is increased on its surface 12.
- a process environment 26 is defined by the gas atmosphere 20 and a present process temperature 25, under which a workpiece temperature 29 adapts to the process temperature 25. Due to the rising workpiece temperature 29, the substance 15 present in the coating 27 reacts with the oxygen 33 from the process environment 26 to form the oxide 21 and forms the protective layer 16 on the base material 23 there forms the protective layer 16.
- the protective layer 16 in turn has a chemically passivating effect, so that a reaction of the surface 12 with oxygen 33 in the process environment 26 is inhibited or avoided. Furthermore, the partial pressure 43 of the oxygen 33 is reduced compared to an ambient atmosphere. If an essentially continuous protective layer 16 is produced on the surface 12 in the third step 130, only carbon 22 is stored in the surface 12, that is to say only the so-called carburizing 31. The carbon 22 is capable of coating the carburizing 31 27 and penetrate the protective layer 16. In the third step 130, the formation of edge oxidations 19 is reduced or prevented, which reduce the strength of the workpiece 10. In the embodiment according to FIG 2 the protective layer 16 is formed essentially from the outside on the workpiece 10.
- a suitable choice of the coating 27 makes it possible to provide any suitable substances 15 for forming the protective layer 16 in a wide range of amounts or concentrations.
- An intensity of Diffusion 17 from the coating 27 into the surface 12 depends on an existing process environment 25, in particular the process temperature 26, and the concentration of the substance 15 in the coating 27.
- FIG 3 An embodiment of the claimed method 100 is shown schematically in three corresponding diagrams 50, each of which has a time axis 52 in the horizontal direction and a size axis 54 in the vertical direction.
- the upper diagram 50 shows on the size axis 54 the workpiece temperature 29 present on a workpiece 10, which results from the action of a process environment 26 to which the workpiece 10 is exposed.
- the diagrams 50 assume a situation in the method 100 in which the first and second method steps 110, 120, that is to say the provision of the workpiece 10, the hardening furnace 30 and the production of a process temperature 25 in the hardening furnace 30 are completed.
- the subsequent third method step 130 has a start phase 35 in which the workpiece temperature 29 rises and approaches the process temperature 25.
- the starting phase 35 ends when a passivation temperature 28 is reached, at which a substance 15, which is present in the workpiece 10 as an alloy element 14, forms an oxide layer on a surface 12 of the workpiece 10, which serves as a protective layer 16.
- a diffusion 17 of this substance 15 begins in the workpiece 10 to the surface 12 thereof.
- a diffusion speed 42 is shown on the size axis 54.
- the diffusion rate 42 of the diffusion 17 of the alloy element 14 for forming the protective layer 16 is essentially zero during the starting phase 35.
- the protective layer 16, as shown in the lower diagram 50 has a thickness 13 of essentially zero.
- the start phase 35 is followed by an acceleration phase 36 in which the workpiece temperature 29 continues to rise.
- the rate of diffusion 42 increases and reaches At the end of the acceleration phase 36 their maximum increase, which in FIG 3 is represented by the tangent 44.
- the thickness 13 of the protective layer 16 has only a slight first increase 46.
- a main phase 37 follows, in which, as shown in the upper diagram 50, the workpiece temperature 29 essentially corresponds to the process temperature 25.
- the diffusion rate 42 of the alloy element 14 in the workpiece 10 remains essentially constant.
- a second increase 47 of the thickness 13 of the protective layer 16 occurs during this time, which exceeds the first increase 46.
- carburization 31 of the workpiece 10 begins during the main phase 37.
- the main phase 37 is followed by a saturation phase 38, in which the workpiece temperature 29 essentially corresponds to the process temperature 25.
- the diffusion rate 42 drops to essentially zero.
- the thickness 13 of the protective layer 16 essentially stagnates during the saturation phase 38.
- the thickness 13 of the protective layer 16 results in a third increase 48, which is less than the first and the second increase 46, 47.
- the carburizing 31 of the workpiece continues 10th
- the saturation phase 38 is followed by a constant phase 39 in which the thickness 13 of the protective layer 16 remains constant and only a carburization 31 takes place due to the action of the process temperature 25 or the process environment 26.
- the combined duration of the main phase 37, the saturation phase 38 and the constant phase 39 represents a process duration 32 which can be set by an algorithm or a table in a control unit 51 of the hardening furnace 30, which is not shown in detail. As an alternative or in addition, the process duration 32 can also be set by user input on the control unit 51.
- a main phase duration 53 which belongs to the process duration 32, depends on the workpiece temperature 29 and the concentration of the substance 15 as an alloy element 14.
- FIG 4 schematically shows the sequence of an embodiment of the claimed method 100.
- the method 100 starts from a first step or method step 110, in which a workpiece 10, which is to be further processed into a gear component 40, is provided. Furthermore, in the first step 110, a hardening furnace 30 is provided with which the claimed method 110 can essentially be carried out.
- a second step 120 follows, in which a process temperature 25 is produced for the workpiece 10 in the hardening furnace 30, at which the method 100 is carried out.
- the process temperature 25 is a component of a process environment 26, which is used to carry out carburizing 31 in the third step 130.
- the process environment 26 also includes the production of a gas atmosphere 20 in which a gaseous carbon compound is present.
- a protective layer 16 is formed on a surface 12 of the workpiece 10.
- the protective layer 16 is formed by a substance 15 which is present as an alloy element 14 in the workpiece 10 or in a coating 27 which can be applied to the workpiece 10 in the first step 110.
- the carburizing 31 of the workpiece 10 also takes place during the third step 130.
- the third step 130 comprises, analogously to the embodiment according to FIG 3 , a starting phase 35, an acceleration phase 36, a main phase 37, a saturation phase 37 and a constant phase 39, in which the protective layer 16 is formed and the carburizing 31 takes place.
- FIG 5 shows a planetary gear 61, which has a housing 65, in which a ring gear 62, a planet carrier 64 with at least one rotatable planet gear 66 and a sun gear 68 are included.
- the ring gear 62, the at least one planet gear 66 and the sun gear 68 are designed as gear components 40, which are produced using one of the claimed methods 100.
- these gear components 40 have an improved quality and can be subjected to higher mechanical loads than comparable gear components according to the prior art. This allows the planetary gear 61 to be made particularly compact.
- a spur gear 63 which has a housing 65 and, as gear components 40, two spur gears 67 which mesh with one another.
- the spur gears 67 are also each produced using a method 100 according to one of the claimed embodiments. Due to the improved quality of the transmission components 40, these can be subjected to higher mechanical stresses than transmission components known from the prior art.
- the spur gear 63 can also be constructed in a particularly compact manner.
- FIG 7 schematically shows the structure of a bevel gear 70, which has two bevel gears 69 in a housing 65, which mesh with one another.
- the bevel gears 69 are manufactured using a method 100 according to one of the claimed embodiments.
- the bevel gears 69 which are gear components 40, can be subjected to higher mechanical loads than known bevel gears. are each made from a transmission component 40 according to the invention.
Abstract
Die Erfindung betrifft ein Verfahren (100) zum Herstellen einer Getriebekomponente (40), das ein Härten eines Werkstücks (10) umfasst. Das Verfahren umfasst einen ersten Schritte (110), in dem ein Bereitstellen des Werkstücks (10) und eines Härteofens (30) erfolgt. Es folgt ein zweiter Schritt (120), in dem eine Prozesstemperatur (25) im Härteofen (30) hergestellt wird. Daran schließt sich eine dritter Schritt (130) an, in dem ein Erzeugen einer Schutzschicht (16) an zumindest einem Bereich einer Oberfläche (12) des Werkstücks (10) erfolgt. Erfindungsgemäßen wird die Schutzschicht (16) basierend auf zumindest einem als Legierungselement (14) im Werkstück (10) vorhandenen Stoff (15) ausgebildet. Alternativ oder ergänzend wird die Schutzschicht (16) basierend auf einem Stoff (15) gebildet, der in einer im Schritt a) auf dem Werkstück (10) aufgebrachten Beschichtung (27) vorliegt. Die Erfindung betrifft auch eine Getriebekomponente (40), deren Herstellung eine Ausführungsform des entsprechenden Verfahrens (100) umfasst. Gleichermaßen betrifft die Erfindung ein Getriebe (60), das über eine entsprechende Getriebekomponente (40) verfügt.The invention relates to a method (100) for producing a gear component (40), which comprises hardening a workpiece (10). The method comprises a first step (110) in which the workpiece (10) and a hardening furnace (30) are made available. A second step (120) follows, in which a process temperature (25) is produced in the hardening furnace (30). This is followed by a third step (130), in which a protective layer (16) is produced on at least a region of a surface (12) of the workpiece (10). According to the invention, the protective layer (16) is formed on the basis of at least one substance (15) present as an alloy element (14) in the workpiece (10). As an alternative or in addition, the protective layer (16) is formed on the basis of a material (15) which is present in a coating (27) applied to the workpiece (10) in step a). The invention also relates to a transmission component (40), the manufacture of which comprises an embodiment of the corresponding method (100). The invention also relates to a transmission (60) which has a corresponding transmission component (40).
Description
Die Erfindung betrifft ein Verfahren zur Herstellung Getriebekomponenten, bei dem ein Werkstück gehärtet wird. Die Erfindung betrifft auch ein Werkstück, das durch das korrespondierende Verfahren gehärtet ist und eine Getriebekomponente, die aus einem solchen Werkstück hergestellt ist. Ebenso betrifft die Erfindung ein Getriebe, das über zumindest eine entsprechende Getriebekomponente verfügt.The invention relates to a method for producing transmission components, in which a workpiece is hardened. The invention also relates to a workpiece that is hardened by the corresponding method and a gear component that is made from such a workpiece. The invention also relates to a transmission which has at least one corresponding transmission component.
Das Dokument
In zahlreichen technischen Gebieten werden gehärtete Komponenten eingesetzt, deren Herstellung einen erheblichen Aufwand erfordert. Des Weiteren besteht in vielen technischen Gebieten die Anforderung, immer leistungsfähigere Komponenten kostengünstiger und schneller bereitzustellen. Dies gilt insbesondere im Bereich der Getriebetechnik, in der hoch beanspruchbare Komponenten gefordert sind. Es besteht Bedarf an einem Herstellungsverfahren für gehärtete Getriebekomponenten, das schnell, prozesssicher, kosteneffizient und einfach umsetzbar ist. Der Erfindung liegt die Aufgabe zugrunde, ein Herstellungsverfahren bereitzustellen, das in zumindest einem der oben skizzierten Aspekte eine Verbesserung bietet.Hardened components are used in numerous technical fields, the manufacture of which requires considerable effort. Furthermore, there is a requirement in many technical areas to provide increasingly powerful components more cost-effectively and faster. This is particularly true in the field of gear technology, in which highly stressable components are required. There is a need for a manufacturing process for hardened transmission components that is quick, reliable, cost-effective and easy to implement. The invention is based on the object of providing a production method which offers an improvement in at least one of the aspects outlined above.
Die Aufgabenstellung wird durch das erfindungsgemäße Verfahren gelöst, das dazu ausgebildet ist, eine Getriebekomponente herzustellen. Das Verfahren umfasst dabei ein Härten des Werkstücks, das zuvor beispielsweise im Rahmen einer sogenannten Weichbearbeitung spanend bearbeitet wurde. Zum erfindungsgemäßen Verfahren gehört unter anderem ein erster Schritt, in dem das Werkstück und ein Härteofen bereitgestellt werden. In einem weiteren Schritt wird durch Einstellen einer Prozesstemperatur im Härteofen eine Prozessumgebung bereitgestellt. Das Werkstück wird in den Härteofen eingebracht und durch die dort vorliegende Prozesstemperatur erwärmt. Durch das Erwärmen des Werkstücks wird eine Werkstücktemperatur an die Prozesstemperatur angeglichen. In einem weiteren Schritt erfolgt ein Erzeugen einer Schutzschicht an zumindest einem Bereich einer Oberfläche des Werkstücks. Die Schutzschicht dient dazu, eine unerwünschte chemische Reaktion der Oberfläche des Werkstücks mit der Prozessumgebung, beispielsweise eine sogenannte Randoxidation des Werkstücks, zu minimieren oder zu vermeiden. Je umfangreicher eine Randoxidation ausgebildet wird, umso größer ist eine Schwächung des bearbeiteten Werkstücks.The task is solved by the method according to the invention, which is designed to produce a transmission component. The method includes hardening the workpiece, which was previously machined, for example, as part of a so-called soft machining. To the invention The process includes a first step in which the workpiece and a hardening furnace are provided. In a further step, a process environment is provided by setting a process temperature in the hardening furnace. The workpiece is placed in the hardening furnace and heated by the process temperature there. A workpiece temperature is adjusted to the process temperature by heating the workpiece. In a further step, a protective layer is produced on at least one area of a surface of the workpiece. The protective layer serves to minimize or avoid an undesired chemical reaction of the surface of the workpiece with the process environment, for example a so-called edge oxidation of the workpiece. The more extensive an edge oxidation is formed, the greater the weakening of the machined workpiece.
Weiter wird das Werkstück der im Härteofen hergestellten Prozessumgebung ausgesetzt und so ein Härtungsvorgang durchgeführt. Erfindungsgemäß wird dabei die Schutzschicht basierend auf einem Stoff gebildet, der als Legierungselement im Werkstück vorliegt. Die Schutzschicht liegt dabei an der Oberfläche des Werkstücks, so dass ein Grundmaterial des Werkstücks durch die Schutzschicht von der Prozessumgebung abgeschirmt wird. Das im Grundmaterial vorliegende Legierungselement wird im Bereich der Oberfläche des Werkstücks in ein Material umgewandelt, das die Schutzschicht auf der Oberfläche ausbildet. Zu diesem Zweck ist für das Werkstück, also dessen Grundmaterial, lediglich ein geeigneter Werkstoff zu wählen, in dem das entsprechende Legierungselement mit einem zumindest ausreichenden Anteil, also einer zumindest ausreichenden Konzentration, vorhanden ist. Die Schutzschicht wird so selbsttätig in gleichmäßiger Weise an der gesamten Oberfläche des Werkstücks ausgebildet. Legierungen sind typischerweise weitestgehend homogen ausgebildet, so dass die Schutzschicht auf der gesamten Oberfläche des Werkstücks im Wesentlichen gleichmäßig ausgebildet wird. Dadurch, dass weitere Handhabungsschritte, beispielweise durch einen Werker, entbehrlich sind, wird ein hohes Maß an Prozesssicherheit erzielt. Ferner wird dadurch die Schutzschicht aus dem Inneren des Werkstücks heraus gebildet.Furthermore, the workpiece is exposed to the process environment produced in the hardening furnace and a hardening process is carried out. According to the invention, the protective layer is formed on the basis of a substance which is present as an alloy element in the workpiece. The protective layer lies on the surface of the workpiece, so that a base material of the workpiece is shielded from the process environment by the protective layer. The alloy element present in the base material is converted in the area of the surface of the workpiece into a material which forms the protective layer on the surface. For this purpose, only a suitable material must be selected for the workpiece, that is to say its base material, in which the corresponding alloy element is present with an at least sufficient proportion, that is to say an at least sufficient concentration. The protective layer is thus automatically formed on the entire surface of the workpiece. Alloys are typically largely homogeneous, so that the protective layer is formed essentially uniformly over the entire surface of the workpiece. The fact that further handling steps, for example by a worker, are unnecessary a high degree of process reliability is achieved. Furthermore, the protective layer is thereby formed from inside the workpiece.
Alternativ oder ergänzend kann die Schutzschicht auch basierend aus einem Stoff ausgebildet werden, der in einer Beschichtung vorliegt. Die Beschichtung wird auf dem Werkstück aufgebracht, wenn das Werkstück im ersten Schritt für das Härten bereitgestellt wird. Durch eine entsprechende Beschichtung je nach vorliegender Prozesstemperatur und/oder Prozessumgebung ist ein besonders geeigneter Stoff zum Ausbilden der Schutzschicht wählbar. Ein besonders geeigneter Stoff ist beispielsweise ein Stoff, der zu einer Schutzschicht umwandelbar ist, die eine hohe chemische Reaktionsträgheit aufweist und somit eine erhöhte Schutzwirkung für die Oberfläche des Werkstücks bietet. Insgesamt wird so für die angestrebte Getriebekomponente die Anzahl an einsetzbaren Werkstoffen als Grundmaterial des Werkstücks erhöht. Ebenso kann in Kombination mit einer Schutzschicht, die aus einem Legierungselement im Grundmaterial des Werkstücks eine weiter gesteigerte Schutzwirkung erzielt werden.Alternatively or in addition, the protective layer can also be formed based on a material that is present in a coating. The coating is applied to the workpiece when the workpiece is made available for hardening in the first step. A particularly suitable material for forming the protective layer can be selected by an appropriate coating depending on the process temperature and / or process environment. A particularly suitable substance is, for example, a substance that can be converted into a protective layer that has a high chemical inertness and thus offers an increased protective effect for the surface of the workpiece. Overall, the number of materials that can be used as the base material of the workpiece is increased for the desired gear component. Likewise, in combination with a protective layer which is made from an alloy element in the base material of the workpiece, a further increased protective effect can be achieved.
In einer weiteren Ausführungsform des beanspruchten Verfahrens kann der Stoff zum Ausbilden der Schutzschicht dazu ausgebildet sein, bei Vorliegen der Prozesstemperatur an der Oberfläche des Werkstücks ein Oxid zu bilden. Alternativ kann das Oxid auch bereits bei einer Temperatur unterhalb der Prozesstemperatur ausgebildet werden. Oxide, insbesondere spezielle Metalloxide, bieten eine Passivierung an einer Oberfläche eines Werkstücks, die eine Randoxidation wirksam verhindert. Der dazu notwendige Sauerstoff ist in einfacher Weise durch die Prozessumgebung bereitstellbar. Des Weiteren sind Oxide chemisch reaktionsträge, was unerwünschten weiteren chemischen Reaktionen mit Stoffen aus der Prozessumgebung und/oder dem Werkstück vorbeugt.In a further embodiment of the claimed method, the material for forming the protective layer can be designed to form an oxide on the surface of the workpiece when the process temperature is present. Alternatively, the oxide can also be formed at a temperature below the process temperature. Oxides, especially special metal oxides, offer passivation on a surface of a workpiece, which effectively prevents edge oxidation. The oxygen required for this can be provided in a simple manner by the process environment. Furthermore, oxides are chemically inert, which prevents undesired further chemical reactions with substances from the process environment and / or the workpiece.
Darüber hinaus kann der Stoff zum Ausbilden der Schutzschicht bei der im Verfahren vorliegenden Prozesstemperatur im Werkstück diffusionsfähig sein. Bei einer Bildung der Schutzschicht basierend auf einem Legierungselement im Werkstück wird so beim Verfahren ein Diffusionsstrom des entsprechenden Legierungselements aus dem Inneren des Werkstücks an dessen Oberfläche hervorgerufen. Infolgedessen wird an der Oberfläche selbsttätig mit dem Legierungselement in ausreichender Menge ein Edukt bereitgestellt, das zum Ausbilden der Schutzschicht erforderlich ist. Ebenso wird der Diffusionsstrom reduziert, wenn das Ausbilden der Schutzschicht in einen Sättigungsbereich eintritt. Damit ist das beanspruchte Verfahren selbstregulierend, was wiederum eine zuverlässige und prozesssichere Umsetzung des Verfahrens erlaubt.In addition, the material for forming the protective layer can be at the process temperature in the workpiece present in the method be diffusible. When the protective layer is formed on the basis of an alloy element in the workpiece, a diffusion current of the corresponding alloy element from the interior of the workpiece on its surface is thus caused during the method. As a result, a sufficient amount of a starting material which is required for forming the protective layer is automatically provided on the surface with the alloy element. The diffusion current is also reduced when the formation of the protective layer occurs in a saturation region. The claimed method is thus self-regulating, which in turn allows the method to be implemented reliably and reliably.
Ferner kann während des Verfahrens, insbesondere im zweiten Schritt, eine Prozessumgebung im Härteofen vorliegen, bei der ein Aufkohlen des Werkstücks erfolgt. Dazu liegt beispielsweise ein ausreichend hohe Prozesstemperatur vor, bei der Kohlenstoff aus der Prozessumgebung in der Oberfläche des Werkstücks eingelagert wird und so die Härte des Werkstücks erhöht wird. Bei einer entsprechenden Prozessumgebung, insbesondere bei einer Prozesstemperatur von 800°C bis 1200°C, ist auch eine Schutzschicht ausbildbar. Randoxidationen sind üblicherweise bei entsprechend hohen Prozesstemperaturen zu erwarten, die auch ein Aufkohlen erlauben. Die Schutzschicht ist dazu geeignet, entsprechenden Prozesstemperaturen standzuhalten und bietet einen zuverlässigen Schutz vor weiterer Randoxidation.Furthermore, during the method, in particular in the second step, there can be a process environment in the hardening furnace in which the workpiece is carburized. For this purpose, for example, there is a sufficiently high process temperature at which carbon from the process environment is embedded in the surface of the workpiece, thus increasing the hardness of the workpiece. A protective layer can also be formed in a corresponding process environment, in particular at a process temperature of 800 ° C to 1200 ° C. Edge oxidations are usually to be expected at correspondingly high process temperatures, which also allow carburizing. The protective layer is suitable to withstand the corresponding process temperatures and offers reliable protection against further edge oxidation.
In einer weiteren Ausführungsform des beanspruchten Verfahrens ist das Legierungselement im Werkstück, aus dem die Schutzschicht auszubilden ist, Chrom, Zirconium, Titan, Nickel, Zink, Aluminium, oder Blei. Die Oxide dieser Stoffe bilden an der Oberfläche des Werkstücks eine chemisch reaktionsträge Schutzschicht, die ein besonders hohes Maß an Schutz vor Randoxidation bietet. Darüber hinaus sind Chrom, Zirconium, Titan, Zink und Aluminium bewährte Legierungselemente zahlreicher Stahlsorten. Folglich sind geeignete Werkstoffe für das Werkstück in einfacher Weise verfügbar. Insbesondere ist Chrom als Stoff zur Bildung einer Schutzschicht, beispielsweise im Rahmen einer sogenannten Chrompassivierung, ein erprobter Stoff. Darüber hinaus ist Chrom bei der im Härteofen vorliegenden Prozesstemperatur gut diffusionsfähig im Werkstück, was die Bildung der Schutzschicht beschleunigt. Dadurch wird die Entstehung von Randoxidationen am Werkstück weiter minimiert.In a further embodiment of the claimed method, the alloy element in the workpiece from which the protective layer is to be formed is chromium, zirconium, titanium, nickel, zinc, aluminum, or lead. The oxides of these substances form a chemically inert protective layer on the surface of the workpiece, which offers a particularly high degree of protection against edge oxidation. In addition, chrome, zirconium, titanium, zinc and aluminum are tried and tested alloying elements for numerous types of steel. As a result, suitable materials for the workpiece are readily available. In particular Chromium is a tried and tested substance as a material for forming a protective layer, for example in the context of a so-called chromium passivation. In addition, chromium is readily diffusible in the workpiece at the process temperature in the hardening furnace, which accelerates the formation of the protective layer. This further minimizes the formation of edge oxidations on the workpiece.
Beim beanspruchten Verfahren kann das Aufbringen der Beschichtung durch Alitieren, durch Chromieren oder durch ein Auftragen einer Paste herstellbar sein. Durch ein Alitieren ist Aluminium als ein Stoff bereitstellbar, der dazu geeignet ist, eine passivierende Schutzschicht, nämlich eine Aluminiumoxidschicht, an der Oberfläche des Werkstücks auszubilden. Durch ein Chromieren wird Chrom bereitgestellt, das eine passivierende Chromoxidschicht bilden kann. Ferner ist in einer Paste ein beliebiger Stoff, insbesondere Titan oder Zirconium, bereitstellbar, der dazu geeignet ist, bei Vorliegen der Prozesstemperatur eine passivierende Schutzschicht auszubilden. Insbesondere kann durch eine Paste auch eine Kombination mehrerer solcher Stoffe bereitgestellt werden. Damit ist das beanspruchte Verfahren in einfacher Weise an eine Vielzahl an Werkstoffen, aus denen das Werkstück hergestellt sein kann, anpassbar.In the claimed method, the coating can be applied by alitizing, by chroming or by applying a paste. Aluminum can be provided by alitizing as a material that is suitable for forming a passivating protective layer, namely an aluminum oxide layer, on the surface of the workpiece. Chromium provides chromium, which can form a passivating chromium oxide layer. In addition, any substance, in particular titanium or zirconium, can be provided in a paste, which is suitable for forming a passivating protective layer when the process temperature is present. In particular, a combination of several such substances can also be provided by a paste. The claimed method can thus be easily adapted to a large number of materials from which the workpiece can be produced.
Ferner kann die Schutzschicht, die während des dritten Verfahrensschritts herzustellen ist, Chromoxid, Aluminiumoxid, Zirconiumoxid, Titanoxid, Nickeloxid, Zinkoxid und/oder Bleioxid aufweisen. Derartige Oxide bieten an der Oberfläche des Werkstücks eine wirksame Passivierung für dieses.Furthermore, the protective layer which is to be produced during the third method step can have chromium oxide, aluminum oxide, zirconium oxide, titanium oxide, nickel oxide, zinc oxide and / or lead oxide. Such oxides provide an effective passivation for the workpiece on the surface.
In einer weiteren Ausführungsform des beanspruchten Verfahrens erfolgt der zweite und/oder dritte Schritt in einer Gasatmosphäre. Dies kann beispielsweise eine sogenannte Aufkohlungsatmosphäre sein, die gasförmige Kohlenstoffverbindungen zur Einlagerung von Kohlenstoff in der Oberfläche des Werkstücks umfasst. Alternativ oder ergänzend kann die Gasatmosphäre auch als Schutzgasatmosphäre ausgebildet sein. Das beanspruchte Verfahren minimiert durch die Schutzschicht das Auftreten von Randoxidationen damit auch in einer Gasatmosphäre. Ein aufwendiges Aufkohlen im Vakuum ist somit durch das beanspruchte Verfahren bei zumindest gleichbleibender Güte am behandelten Werkstück ersetzbar. Dadurch wird die Herstellung der Getriebekomponenten beschleunigt und gleichzeitig die Qualität der behandelten Werkstücke beibehalten oder erhöht. Dadurch sind die angestrebten Getriebekomponenten insgesamt kosteneffizienter herstellbar.In a further embodiment of the claimed method, the second and / or third step takes place in a gas atmosphere. This can be a so-called carburizing atmosphere, for example, which comprises gaseous carbon compounds for the incorporation of carbon in the surface of the workpiece. Alternatively or in addition, the gas atmosphere can also be designed as a protective gas atmosphere. The claimed process minimizes the occurrence of edge oxidations even in a gas atmosphere due to the protective layer. Complex carburizing in a vacuum can thus be replaced by the claimed method while the quality of the treated workpiece remains at least constant. This speeds up the manufacture of the gear components and at the same time maintains or increases the quality of the treated workpieces. As a result, the desired transmission components can be manufactured more cost-effectively overall.
Beim beanspruchten Verfahren kann das Werkstück aus einem Stahl oder einer Stahllegierung hergestellt sein. Stähle oder Stahllegierungen sind in einem breiten Spektrum von Eigenschaften verfügbar und sind zuverlässig, also prozesssicher bearbeitbar. Ferner sind Stahl oder Stahllegierungen dazu geeignet, als Grundmaterial für Werkstücke zu dienen, auf dem eine Schutzschicht auszubilden ist, die eine passivierende Wirkung aufweist. Insbesondere bietet Stahl oder Stahllegierung vorteilhafte Festigkeit, die für Getriebekomponenten unerlässlich ist.In the claimed method, the workpiece can be made of a steel or a steel alloy. Steels or steel alloys are available in a wide range of properties and can be processed reliably, i.e. reliably. Furthermore, steel or steel alloys are suitable for serving as the base material for workpieces, on which a protective layer is to be formed which has a passivating effect. In particular, steel or steel alloy offers advantageous strength, which is essential for gear components.
Darüber hinaus kann der dritte Verfahrensschritt, in dem die Schutzschicht ausgebildet wird, für die Dauer einer einstellbaren Prozessdauer durchgeführt werden. Die Prozessdauer ist dabei in Abhängigkeit einer Mehrzahl an Größen wählbar. Insbesondere ist die Prozessdauer in Abhängigkeit von der Prozesstemperatur gewählt. Je geringer die Prozesstemperatur ist, umso länger dauert es, bis durch Diffusion aus dem Inneren des Werkstücks eine ausreichende Schutzschicht ausgebildet ist. Die Prozessdauer ist dabei derart einstellbar, dass während des dritten Verfahrensschritts beim Ausbilden der Schutzschicht eine Sättigung eintritt. Ebenso ist die Prozessdauer in Abhängigkeit vom eingesetzten Werkstoff des Werkstücks und/oder der aufgebrachten Beschichtung einstellbar. Die Prozessdauer kann auch eine sogenannte Aufkohlungsphase umfassen, in der das Ausbilden der Schutzschicht abgeschlossen ist und lediglich ein Aufkohlen des Werkstücks erfolgt. Die Prozessdauer ist dabei beispielsweise durch einen Algorithmus oder eine Tabelle in einer Steuereinheit des Härteofens einstellbar. Alternativ oder ergänzend kann die Prozessdauer auch durch eine Benutzereingabe einstellbar sein.In addition, the third method step in which the protective layer is formed can be carried out for the duration of an adjustable process duration. The process duration can be selected depending on a number of sizes. In particular, the process duration is selected depending on the process temperature. The lower the process temperature, the longer it takes until a sufficient protective layer is formed by diffusion from the inside of the workpiece. The duration of the process can be set such that saturation occurs during the third method step when the protective layer is formed. The process duration can also be set depending on the material used for the workpiece and / or the coating applied. The process duration can also include a so-called carburizing phase, in which the formation of the protective layer is completed and only the workpiece is carburized. The process duration is, for example, by a Algorithm or a table adjustable in a control unit of the hardening furnace. As an alternative or in addition, the process duration can also be adjustable by user input.
Des Weiteren kann die Prozessdauer auch in Abhängigkeit eines Anteils des Legierungselements eingestellt werden, das zum Ausbilden der Schutzschicht vorgesehen ist. Unter dem Anteil ist dabei beispielsweise die Konzentration des entsprechenden Legierungselements im Werkstoff des Werkstücks zu verstehen. Je höher der Anteil des Legierungselements im Werkstück ist, umso schneller wird die Schutzschicht an der Oberfläche des Werkstücks ausgebildet. Alternativ oder ergänzend kann die Prozessdauer auch in Abhängigkeit von einer Diffusionsgeschwindigkeit des entsprechenden Legierungselements im Werkstück ausgewählt werden. Je höher die Diffusionsgeschwindigkeit des Legierungselements im Werkstück ist, umso schneller wird die Schutzschicht ausgebildet. Das beanspruchte Verfahren ist damit in einfacher Weise an den eingesetzten Werkstoff anpassbar.Furthermore, the process duration can also be set as a function of a proportion of the alloy element that is provided for forming the protective layer. The proportion is to be understood as the concentration of the corresponding alloying element in the material of the workpiece, for example. The higher the proportion of the alloy element in the workpiece, the faster the protective layer is formed on the surface of the workpiece. Alternatively or additionally, the process duration can also be selected as a function of a diffusion rate of the corresponding alloy element in the workpiece. The higher the diffusion rate of the alloy element in the workpiece, the faster the protective layer is formed. The claimed method can thus be easily adapted to the material used.
In einer weiteren Ausführungsform des beanspruchten Verfahrens kann ein Partialdruck von Sauerstoff im Härteofen gegenüber einer Umgebungsatmosphäre verringert sein. Dementsprechend liegt im Härteofen ein reduziertes Sauerstoffangebot vor, durch das das Entstehen einer Randoxidation weiter gehemmt wird. Hierdurch wird die Wirkung des beanspruchten Verfahrens weiter gesteigert, so dass der für die Getriebekomponenten eingesetzte Werkstoff noch stärker ausgenutzt werden kann.In a further embodiment of the claimed method, a partial pressure of oxygen in the hardening furnace can be reduced compared to an ambient atmosphere. Accordingly, there is a reduced supply of oxygen in the hardening furnace, which further inhibits the formation of edge oxidation. This further increases the effect of the claimed method, so that the material used for the gear components can be used even more.
Die zugrundeliegende Aufgabenstellung wird auch durch ein erfindungsgemäßes Werkstück gelöst, das zur Herstellung beispielweise einer Getriebekomponente geeignet ist. Alternativ kann das Werkstück auch zur Herstellung einer Verdichterschaufel oder einer Turbinenschaufel in einer Turbomaschine geeignet sein. Das Werkstück ist gehärtet und ist für eine unmittelbar folgende Hartbearbeitung geeignet. Das Werkstück stellt damit ein Zwischenprodukt bei der Herstellung einer Getriebekomponente bzw. einer Verdichter- oder Turbinenschaufel dar. Erfindungsgemäß ist das Werkstück in einem Verfahren nach einer der oben skizzierten Ausführungsformen bearbeitet. Infolgedessen weist das erfindungsgemäße Werkstück höchstens ein Minimum an Randoxidationen auf, die die Festigkeit des Werkstücks herabsetzen. Das erfindungsgemäße Werkstück hat die Behandlung durch das oben beschriebene Verfahren abgeschlossen und ist unmittelbar zu einem Abschrecken, Anlassen und/oder Aufheizen geeignet, an das sich eine spanende Hartbearbeitung anschließt. Ein weiterer Bearbeitungsschritt zwischen dem Härten und dem Hartbearbeiten, wie beispielsweise ein Kugelstrahlen, ist entbehrlich. Durch das erfindungsgemäße Werkstück wird die Herstellung einer Getriebekomponente erheblich beschleunigt und vereinfacht, was in einer gesteigerten Wirtschaftlichkeit resultiert. Die gleichen Vorteile werden auch bei der Herstellung einer Verdichterschaufel oder einer Turbinenschaufel einer Turbomaschine erzielt.The underlying task is also solved by a workpiece according to the invention, which is suitable for the production of, for example, a gear component. Alternatively, the workpiece can also be suitable for producing a compressor blade or a turbine blade in a turbomachine. The workpiece is hardened and is suitable for immediate hard machining. The workpiece thus represents an intermediate product in the manufacture of a Gear component or a compressor or turbine blade. According to the invention, the workpiece is processed in a method according to one of the embodiments outlined above. As a result, the workpiece according to the invention has at most a minimum of edge oxidations, which reduce the strength of the workpiece. The workpiece according to the invention has completed the treatment by the method described above and is immediately suitable for quenching, tempering and / or heating, which is followed by hard machining. Another processing step between hardening and hard machining, such as shot peening, is unnecessary. The workpiece according to the invention considerably accelerates and simplifies the manufacture of a transmission component, which results in increased economy. The same advantages are also achieved in the manufacture of a compressor blade or a turbine blade of a turbomachine.
Gleichermaßen wird die skizzierte Aufgabenstellung durch die erfindungsgemäße Getriebekomponente gelöst. Die Getriebekomponente ist als Stirnrad, Hohlrad, Planetenrad, oder als Sonnenrad für ein Planetengetriebe bzw. ein Stirnradgetriebe ausgebildet. Die Getriebekomponente ist dabei aus einem Werkstück hergestellt, das nach einem Verfahren gemäß einer der oben beschriebenen Ausführungsformen ausgestaltet ist. Dementsprechend ist die Getriebekomponente aus einem wie oben beanspruchten Werkstück hergestellt. Die Getriebekomponente weist höchstens ein Minimum an Randoxidationen auf, durch die die Festigkeit der Getriebekomponente reduziert wird. Die Getriebekomponente ist infolgedessen kompakter dimensionierbar als bekannte Getriebekomponenten, die bestimmungsgemäß gleichen mechanischen Beanspruchungen unterworfen sind. Demnach bietet die beanspruchte Getriebekomponente eine erhöhte Werkstoffausnutzung und erhöhte Leistungsdichte.Likewise, the problem outlined is solved by the transmission component according to the invention. The gear component is designed as a spur gear, ring gear, planet gear, or as a sun gear for a planetary gear or a spur gear. The gear component is made from a workpiece that is designed according to a method according to one of the above-described embodiments. Accordingly, the gear component is made from a workpiece as claimed above. The gear component has at most a minimum of edge oxidation, by means of which the strength of the gear component is reduced. As a result, the gear component can be dimensioned more compactly than known gear components, which are intended to be subjected to the same mechanical stresses. Accordingly, the stressed gear component offers increased material utilization and increased power density.
Die zugrundeliegende Aufgabenstellung wird auch durch das erfindungsgemäße Getriebe gelöst. Das Getriebe kann beispielsweise als Planetengetriebe oder Stirnradgetriebe ausgebildet sein und weist ein Gehäuse auf, in dem eine Mehrzahl an Getriebekomponenten ausgenommen ist. Dabei ist zumindest eine der Getriebekomponenten gemäß der oben beschriebenen Lösung ausgebildet, also aus einem Werkstück hergestellt, das nach einem beanspruchten Verfahren behandelt ist. Durch die zumindest eine Getriebekomponente, die mit dem beanspruchten Verfahren bearbeitet ist, wird eine verbesserte Werkstoffausnutzung erzielt, was wiederum eine kompaktere Dimensionierung der Getriebekomponente erlaubt. Derart verbesserte Getriebekomponenten wiederum ermöglichen es, das erfindungsgemäße Getriebe kompakter herzustellen.The underlying task is also solved by the transmission according to the invention. The transmission can be designed, for example, as a planetary gear or spur gear be and has a housing in which a plurality of transmission components is excluded. In this case, at least one of the gear components is designed according to the solution described above, that is to say it is produced from a workpiece that is treated according to a claimed method. Improved material utilization is achieved by the at least one gear component, which is processed with the claimed method, which in turn allows a more compact dimensioning of the gear component. Such improved transmission components in turn make it possible to manufacture the transmission according to the invention more compactly.
Die Erfindung wird im Folgenden anhand einzelner Ausführungsformen beschrieben. Die Merkmale der einzelnen Ausführungsformen sind dabei untereinander kombinierbar. Die Figuren sind zumindest insoweit in gegenseitiger Ergänzung zu lesen, dass gleiche Bezugszeichen in den Figuren auch die gleiche technische Bedeutung haben. Es zeigen im Einzelnen:
- FIG 1
- eine schematische Darstellung einer ersten Ausführungsform des beanspruchten Verfahrens;
- FIG 2
- eine schematische Darstellung einer zweiten Ausführungsform des beanspruchten Verfahrens;
- FIG 3
- ein Ablaufdiagramm einer dritten Ausführungsform des beanspruchten Verfahrens;
- FIG 4
- ein Ablaufdiagramm einer vierten Ausführungsform des beanspruchten Verfahrens;
- FIG 5
- eine schematische Darstellung einer Ausführungsform eines beanspruchten Getriebes mit einer beanspruchten Getriebekomponente
- FIG 6
- eine schematische Darstellung einer weiteren Ausführungsform eines beanspruchten Getriebes mit einer beanspruchten Getriebekomponente.
- FIG. 1
- a schematic representation of a first embodiment of the claimed method;
- FIG 2
- a schematic representation of a second embodiment of the claimed method;
- FIG 3
- a flow diagram of a third embodiment of the claimed method;
- FIG 4
- a flow diagram of a fourth embodiment of the claimed method;
- FIG 5
- is a schematic representation of an embodiment of a claimed transmission with a claimed transmission component
- FIG 6
- a schematic representation of a further embodiment of a claimed transmission with a claimed transmission component.
Das Werkstück 10 befindet sind während des dritten Verfahrensschritts 130 in einem Härteofen 30, in dem eine Gasatmosphäre 20 vorliegt. Die Gasatmosphäre 20 weist eine gasförmige Kohlenstoffverbindung auf, die dazu geeignet ist, im Bereich der Oberfläche 12 des Werkstücks 10 Kohlenstoff 22 einzulagern. Dadurch wird ein sogenanntes Aufkohlen verwirklicht, durch das die Härte des Werkstücks 10 nach dem Abschrecken an seiner Oberfläche 12 erhöht wird. Durch die Gasatmosphäre 20 und eine vorliegende Prozesstemperatur 25 wird eine Prozessumgebung 26 definiert, unter der sich eine Werkstücktemperatur 29 der Prozesstemperatur 25 anpasst. Durch die steigende Werkstücktemperatur 29 reagiert der in der Beschichtung 27 vorliegende Stoff 15 mit dem Sauerstoff 33 aus der Prozessumgebung 26 zu dem Oxid 21 und bildet auf dem Grundmaterial 23 die Schutzschicht 16. Das Oxid 21 besetzt die Oberfläche 12 im Bereich der Beschichtung 27 flächig und bildet dort die Schutzschicht 16. Die Schutzschicht 16 wiederum hat eine chemisch passivierende Wirkung, so dass eine Reaktion der Oberfläche 12 mit Sauerstoff 33 in der Prozessumgebung 26 gehemmt oder vermieden wird. Ferner ist der Partialdruck 43 des Sauerstoffs 33 gegenüber einer Umgebungsatmosphäre reduziert. Wenn im dritten Schritt 130 an der Oberfläche 12 eine im Wesentlichen durchgehende Schutzschicht 16 erzeugt ist, erfolgt nur noch eine Einlagerung von Kohlenstoff 22 in der Oberfläche 12, also nur noch das sogenannte Aufkohlen 31. Der Kohlenstoff 22 ist fähig, beim Aufkohlen 31 die Beschichtung 27 und die Schutzschicht 16 zu durchdringen. Im dritten Schritt 130 wird das Entstehen von Randoxidationen 19 reduziert oder unterbunden, die die Festigkeit des Werkstücks 10 herabsetzen. Bei der Ausführungsform nach
In
Auf die Startphase 35 folgt eine Beschleunigungsphase 36, in der die Werkstücktemperatur 29 weiter ansteigt. Gleichzeitig steigt die Diffusionsgeschwindigkeit 42 an und erreicht zum Ende der Beschleunigungsphase 36 ihren maximalen Zuwachs, der in
An die Sättigungsphase 38 schließt sich eine Konstantphase 39 an, in der die Dicke 13 der Schutzschicht 16 konstant bleibt und durch die Einwirkung der Prozesstemperatur 25 bzw. der Prozessumgebung 26 nur noch ein Aufkohlen 31 stattfindet. Die kombinierte Dauer der Hauptphase 37, der Sättigungsphase 38 und der Konstantphase 39 stellt eine Prozessdauer 32 dar, die durch einen Algorithmus oder eine Tabelle in einer nicht näher dargestellten Steuereinheit 51 des Härteofens 30 einstellbar. Alternativ oder ergänzend ist die Prozessdauer 32 auch durch eine Benutzereingabe an der Steuereinheit 51 einstellbar. Dabei ist eine Hauptphasendauer 53, die zur Prozessdauer 32 gehört, von der Werkstücktemperatur 29 und der Konzentration des Stoffs 15 als Legierungselement 14 abhängig.The saturation phase 38 is followed by a
In
In
Claims (15)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP18189472.6A EP3611289A1 (en) | 2018-08-17 | 2018-08-17 | Method of manufacturing hardened components for gear boxes and gear boxes |
PCT/EP2019/071704 WO2020035487A1 (en) | 2018-08-17 | 2019-08-13 | Method for producing hardened workpieces for a gear component and a gear mechanism |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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EP18189472.6A EP3611289A1 (en) | 2018-08-17 | 2018-08-17 | Method of manufacturing hardened components for gear boxes and gear boxes |
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Publication Number | Publication Date |
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EP3611289A1 true EP3611289A1 (en) | 2020-02-19 |
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EP18189472.6A Withdrawn EP3611289A1 (en) | 2018-08-17 | 2018-08-17 | Method of manufacturing hardened components for gear boxes and gear boxes |
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EP (1) | EP3611289A1 (en) |
WO (1) | WO2020035487A1 (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3885995A (en) * | 1973-04-10 | 1975-05-27 | Boeing Co | Process for carburizing high alloy steels |
EP2103707A1 (en) * | 2008-03-20 | 2009-09-23 | Minebea Co. Ltd. | An aerospace bearing component |
WO2010097300A1 (en) | 2009-02-26 | 2010-09-02 | Basf Se | Protective coating for metallic surfaces and production thereof |
US20150211621A1 (en) * | 2014-01-28 | 2015-07-30 | Ruebig Gesellschaft m.b.H. & Co. KG. | Sintered component |
-
2018
- 2018-08-17 EP EP18189472.6A patent/EP3611289A1/en not_active Withdrawn
-
2019
- 2019-08-13 WO PCT/EP2019/071704 patent/WO2020035487A1/en active Application Filing
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3885995A (en) * | 1973-04-10 | 1975-05-27 | Boeing Co | Process for carburizing high alloy steels |
EP2103707A1 (en) * | 2008-03-20 | 2009-09-23 | Minebea Co. Ltd. | An aerospace bearing component |
WO2010097300A1 (en) | 2009-02-26 | 2010-09-02 | Basf Se | Protective coating for metallic surfaces and production thereof |
US20150211621A1 (en) * | 2014-01-28 | 2015-07-30 | Ruebig Gesellschaft m.b.H. & Co. KG. | Sintered component |
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