WO2013113302A1 - Method for the mechanical edge zone hardening of components - Google Patents

Description

 Method for mechanical edge zone hardening

 of components

The invention relates to a method for mechanical Randzonenverfestigung within a component edge zone of a component with at least one rolling tool according to the closer in the upper ^¬ concept of claim 1.

Jet engines are known from practice, which are executed downstream of a fan with multi-stage compressors, in the area of which guided in a core stream air ^¬ stream is gradually guided to a desired pressure level. Individual compressor stages are formed by blade elements or rotating rotor blades rotating in operation of a jet engine and corresponding blade elements or stationary stator blades. In the field of stationary guide wheels act during operation of a jet ^¬ drive relatively low mechanical loads, on the one hand ^¬ attack no rotational centrifugal forces and on the other hand blade vibrations are minimized by the residual stress of the airfoil of the foot and head area.

In contrast, work in the field of rotating rotor blades but ^¬ during operation of a jet engine high me ^¬ chanical loads. Their total load consists of several partial loads, of which the centrifugal force represents the largest part load.

The dynamic partial loads resulting from the rotation ^¬ induced vibration excitation of the blades or blade elements. Furthermore, act on the blades aerodynamic loads, especially on periodic unsteady currents are due. Generally occur periodically unsteady flows through the stator-rotor interaction, which is evidence by the division of the flow by the passage of the rotor blades to the guide vanes he ^¬. Furthermore, dynamic loads are caused by the in ^¬ teraktion the flow profile with turbulent flow, which also have blade vibrations result.

The sum of the dynamic part loads means that high-frequency Schwingun ^¬ gen occur especially in the field of rotating rotor blades of compressors and also of brass or generally of one-piece rotor preparation ^¬ chen jet engine during operation that result in a highly dynamic loading of the rotor blades. Furthermore, part of the blades during operation of jet engines in addition to mechanical stresses thermally stressed. This is especially true for the blades of the high-pressure compressor and the rear blades of Nie ^¬ derdruckverdichters where operating temperatures of up to 600 ° C can be achieved.

Vanes of compressors or blowers of jet engines ^¬ stations are designed such that the dynamic operation ^¬ not overload the fatigue strength or defined only step over ^¬ and fatigue strength and a defined amount of time is guaranteed strength. However, there is always a premature crack initiation and sometimes even an uncontrolled failure of fan and compressor ^¬ blades, which is mainly due to a blade damage by foreign bodies.

Foreign body damage is caused by the impact of hard foreign bodies, which are the foreign bodies generally around stones and fragments of screws, Courage ^¬ tern, washers and the like is lying on the start and the runway.

If a foreign body ^strikes the jet engine, for example, it often ^shatters . Mostly, these fragments also penetrate deeper into the engine as objects that have passed through the fan section collision-free, with the air flow. If the engine has a large flow of secondary air, some of the objects may leave the engine over it without causing further substantial damage. The other part comes with the Kernluftström in Niederdruckver ^¬ dense and there is momentous collisions, especially with the rapidly rotating blades, one. Due to the kinematics, the main damage location is similar to the blower, in the area of a leading edge and the front concave profile side.

The blade elements are correspondingly massive out ^¬ leads to protect the blade elements or rotor blades against ^¬ over foreign body damage and avoid from these at Be ^¬ drove each resulting cracking in the shop ^¬ feln. The undesirably high material usage increases a total weight and manufacturing costs of a jet ^¬ drive, which is not desirable.

To this regard improve the blade elements has been gone over, blades or blade elements of jet engines on appropriate production processes demand solidify to run the blades compared to non nachverfestigten blades with lower Bauteilabmessun ^¬ gen or the resistance to vibration ^¬ fatigue to increase. For this purpose it is known to roll blades with pliers work ^¬ testify regionally and generate ^¬ chen in near-surface preparation residual stresses in the blades. In each case one of the flow facing blade area is solidified by an engagement of a rolling tool by deep rolling. Here, usually in about 20% of the surface of a blade element, starting from the Strö ^¬ mung inlet edge of the blade element in the flow direction by simultaneous double-sided rolling, whereby a high surface quality is achieved or maintained and also deformations thin-walled profiles are avoided. 10 2011 007 223.3 of the Rolls-Royce Germany Ltd. & Co KG, for example in the patent application DE - - Pliers ^¬ tools used, which can vary a processing pressure during Oberflächenverfesti ^¬ supply to avoid internal stress cracks and grooves are doing.

Such pliers tools are designed with respect to a maxima ^¬ len use pressure, so that these tools are in total made very large ^¬ together. Especially with complex of ^¬ formed to solidifying components, as are running show ^¬ feln of jet engines, is restricted to be available ^¬ de room for the introduction of the plier tool. Accordingly ^¬ speaking can be solidified with the out for a maximum operating pressure ^¬ loaded pliers tool may not be the entire ge ^¬ desired area of the component.

The present invention therefore has the object ^¬ provide a method for the mechanical surface zone solidification within a component edge zone of a component with at least one rolling tool to provide, by means of which Even in complex trained components desired areas can be solidified.

According to the invention this object is achieved by a method having the features of claim 1.

It is nigstens proposed a rolling tool, a method for mechanical Randzonenverfesti ^¬ supply within a component edge zone of a component with we ^¬, wherein residual stresses are introduced by the at least one rolling tool by means of deep rolling in oberflä ^¬-near regions of the component, and wherein during the deep rolling in each case a portion of the Component between areas of at least one rolling mill ^¬ tool is arranged and two sides of the component simultane- ^{ously be} tig grinded. According to the invention it is provided that the component of at least two rolling tools in the region of the solidification range is deep rolled, which exert a differing from each other, in each case at least approximately constant pressure force to the component made ^¬ during the deep rolling.

The fact that at least two rolling tools are used for Randzo ^¬ nenverfestigung a component, each ^¬ Weil applied for applying an at least approximately constant pressure force, they can be designed with respect to the specific pressure force and need not have means for pressure variation, so that the rolling tools and their supply, control and Regi ^¬ treatment units very easily and inexpensively trained who ^¬ can.

Accordingly, the rolling ^tools used in the method according to the invention can be smaller than known rolling tools. Tools are sized. This results in a better accessibility of the rolling tools is provided to the at least one bonding area, in particular in complex formed components and a risk of collision of the respective rolling mill ^¬ zeugs with other components or other surfaces of the component to bear ^¬ beitenden is reduced. Further, by the small-sized rolling tools optionally further extending from an edge region of the component engaging in the component as in known rolling tools made ^¬ who.

Basically, the individual rolling tools can sequenced ^¬ tially, that are used in succession. To reduce machining ^¬-up time but it is also conceivable that individual ^¬ nen rolling tools at least partly simultaneously einzuset ^¬ zen.

By the method according to the invention components compared to nichtververfestigten components with lower material usage and thus smaller total weight with the same or higher resistance to foreign body damage and vibration loads executable.

Overall, components that are solid-rolled by the method according to the invention, robust in terms of a

Crack initiation, crack propagation, erosion damage and foreign body damage, since the component is more resistant by the Oberflächenver ^¬ fortification and has a longer service life.

By the deep rolling process, a surface of the construction ^¬ is partly also smoothed out, creating, beispielswei ^¬ se in an insert around which flow from a fluid components a very good we- kungsgrad have. The smooth-hardened surface are very few notch roots and the tops ^¬ surface is particularly resistant to damage. This in turn has a positive effect on the life of the building ^¬ partly out.

The method according to the invention is used in particular for edge zone consolidation of rotor blades of a blade wheel for a jet engine, wherein the rotor blades can be connected in a form- ^fitting manner to a disk wheel or can be formed integrally with a disk wheel. Derar ^¬ ed blades have complex free-form geometries, which are difficult to access. Owing to the particularly small From ^¬ formation of the rolling tools is a processing of run show ^¬ feln example, in the leading edge facing away from Be ^¬ rich, let the region of a blade tip in the area of FIL, that in a transition region between a blade ^¬ blade and a blade root , possible. You can also edit several of these areas in combination. Due to the deep rolling of the surfaces of the blades, the wide ^¬ ren voltage jumps are avoided and improves the resistance to vibration loads in a simple manner.

The blade is solidly rolled in an advantageous embodiment of the method according to the invention in the region of a leading edge. The shape of the festzuwalzenden range can be freely selected and may for example be substantially rectangular-shaped and square ^¬ start directly at the leading edge. The method according to the invention can also be used for the treatment of a damaged area, for example a solid body, whereby the area treated by the rolling tools in particular fully fully ^encloses the defective area. In an advantageous embodiment of the method according to the invention, a first processing region of the component is first deep rolled in a first machining step with a first pressing force by a first roller tool and ^¬ closing a second, at least, at least as a rim area of the first processing area of the component region ^¬, in particular completely, and / or overlapping, umfas ^¬ transmitter processing section of the component in a second Bear ^¬ beitungsschritt with respect to the first pressing force ^¬ re duced second pressing force by a second rolling tool deep rolled. By processing the edge zone region of the first processing region, residual stress jumps at a transition between a region treated by a rolling ^tool and an untreated region can be greatly reduced.

Residual stress jumps can be further reduced if at least one further, at least one edge zone region of the second processing region of the component is at least be ^¬ rich, in particular completely and / or overlapping, comprehensive machining region of the component with a ^¬ against the second pressure force respectively reduced compressive force is rolled. The more machining areas are provided and the smaller the pressure differences between the respective processing areas are selected, the lower the residual stress cracks and the more uniform are the jewei ^¬ then transitions.

In an advantageous embodiment of the method according to the invention, the rolling tools are guided relative to the building ^¬ part, that a distance between edge zones of the respec ^¬ ver processing areas of the component on the course we- at least approximately constant. Alternatively, it can also be provided that the rolling tools are guided in such a way relative to the component such that a distance between Randzo ^¬ NEN the respective processing areas of the component via de ^¬ ren course varied. Also, it may be provided that the distance between two adjacent edge zones is Annae ^¬ hernd least constant, but is different from a distance between two other adjacent edge zones. This can be advantageous in particular ^¬ sondere for reducing stress concentration and stress ^¬ jumps, so that the risk of Rissent ^¬ stehung can be reduced.

In an inventive method, it can be seen also pre ^¬ that initially a first processing region of the component hardened by rolling in a first processing step at a first pressure force from a first roller tool and ^¬ closing a second partially, in particular completely encompassed by the first processing area processing region of the component is rolled in a second processing step with a relation to the first pressure force increased second compressive force of a second rolling tool. Even with this processing sequence, residual stress jumps at a transition between a region treated by a rolling ^tool and an untreated region can be greatly reduced.

Also in this order of the pressure introduction residual stresses can be particularly effectively reduced and a more uniform transition between a fixed-rolled portion and an untreated region not be obtained if we ^¬ nigstens another processing area of the component is firmly rolled with a respect to the second pressing force increased pressure force, wherein said at least partially, in particular which is completely covered by the second processing area. The more processing areas are provided and the ge ^¬ ringer the pressure difference is, the greater is this Ef ^¬ effect.

In a marked by a low control and regulating effort variant of the inventive method, the surfaces of the component to be deep rolled at least bereichswei ^¬ se by sequentially radia ^¬ les or sequential axial retraction. Alternatively, the surfaces of the component can be rolled by any routes of the respective roll ^¬ tool, it has proved to be particularly ef ^¬ fectively when the deep rolling process particularly in a meandering movement of the respective roller ^¬ is tool carried out relative to the component.

Both the features specified in the claims and the features specified in the following embodiment of the inventions ^¬ inventive article are each suitable alone or in any combination with each other to further develop the subject invention. The respective combinations of features provide in terms of Wei ^¬ terbildung of the subject of the invention, no limitation ^¬ A, but instead have to just play with ^¬ like character essentially.

Further advantages and advantageous embodiments of the inventive subject matter will emerge from the patent applica ^¬ claims and the embodiment described in principle below with reference to drawings.

It shows: 1 is a highly schematic longitudinal ^sectional view of a jet engine with several Schaufelrä ^¬ countries;

2 is an enlarged detail view of a show ^¬ felrads of Figure 1 with multiple blades.

Figure 3 is a simplified view of a blade of the impeller of Figure 2, wherein the running ^¬ shovel is Festge ^¬ rolls in the region of a leading edge..; and

Fig. 4 is a view corresponding to FIG. 3, the run ^¬ scoop, wherein two processing strategies for deep rolling of the blade are shown.

In Fig. 1, a jet engine 1 is shown in a longitudinal ^¬ sectional view. The jet engine 1 is designed with an inlet region 3, which is followed downstream by a fan 4 in a manner known per se. Again stream ^¬ from the fan 4, the fluid stream splits in the jet engine ^¬ factory 1 in a side stream and a core stream, the side stream flows through a bypass channel 2 and the core stream into an engine core 5, which in turn in ^¬ ter ^¬ ter type and Way with a compressor device 6, a burner 7 and a turbine device 8 is executed.

In Fig. 2 is an enlarged detail view of a Schau ^¬ felrads 9 of the compressor device 6 is shown, which comprises an annular base body 10 and a plurality of circumferentially distributed blades 11, which extend substantially from the base body 10 radially. The rotor blades 11 may be integrally formed with the base body 10 and constitute a so-called blisk, ie an integrally bladed rotor construction. The term blisk is composed of the English words "blade" for shovel and "disk" for disc. The disc or the annular base body 10 and the blades 11 are made of one piece. The blades of the integrally beschau ^¬ felten paddle wheel 9 are advantageously arranged with a smaller distance from each other, whereby a maximum possible compression and efficiency can be improved.

Alternatively, the blades can also have blade ^¬ feet and inserted in the latter in the base body 10 provided ^¬ provided grooves and thereby be interchangeably connected to the base body 10 and disk wheel.

To run the compressor means 6 and the paddle wheel 9 ge ^¬ genüber foreign object damage and also vibration loads at the same time low weight stable, are introduced into the moving blades 11 via respectively between adjacent rotor blades 11 engaging, in particular pincer-like rolling tools within a near-surface component edge zone in a fixed rolling process residual stresses. Each a is in the range of a leading edge 13 of the blade 11 is disposed ^¬ solidification region 14 of the blades 11 is present on both sides, ie Festge rolls ^¬ simultaneously on both a suction than on a pressure side of the blade. 11

The deep rolling of the surfaces of the rotor blades 11 respectively solidify areas of the rotor blade 9 near the surface by increasing the dislocation density and Layer of the blades 11 hardened. The curing of the edge ^¬ layer reduces the risk of cracks, which resul ^¬ animals from a foreign object damage as well as from vibration loads. In addition, the introduced compressive residual stresses into the material through the solid ^¬ rollers guide the region of the running ^¬ blade 11 means that this counter, and after formation of a crack a crack propagation thus a positive Ef ^¬ fect as regards the fatigue strength and thus bezüg ^¬ Lich the life of the jet engine 1 have.

11 further have the rotor blades by the fixed rolling process a high surface quality on with a small upper ^¬ surface roughness which has a positive effect on the Aerody ^¬ namic quality of the blades 11 and the entire show ^¬ felrades 9 without the need of a further, at the solidification process subsequent process step for Glät ^¬ tion of the surface has.

To carry out the deep rolling process, rolling tools which are not shown in more detail are provided, which are basically designed in a manner known per se and can be integrated into any known machining center.

The rolling tools are each designed to exert a con ^¬ constant pressure force on the blade 11, so that the respective rolling tool can be designed with respect to this pressure force. The rolling tools which are designed to exert a small roll separating force may be correspondingly small dimensions, so that a deeper A ^¬ reached into the blades 11 permits these and a Kollisi ^¬ onsgefahr of the respective rolling tool is reduced, for example, with surfaces of adjacent blades 11 , In FIG. 3, a blade 11 is shown in a highly simplified ^manner , the surface of which has been firmly rolled successively in the area of the leading edge 13 with four rolling tools in the present case. The solidification region 14 here has a rectangular Wesentli ^¬ chen form which is directly adjacent to the Anströmkan ^¬ te here 13 and each has a distance to both tip and a transition region 12 to a blade root 26 on ^¬. But the solidification range can in principle have any shape or cover the entire surface of the running ^¬ shovel. 11

It can also be provided that is Verfestigungsbe ^{¬ ¬} rich 14 is arranged in the area of an impact of a harmful body in order to reduce the effect of impact.

By means of a pincer-shaped design of the rolling tools, a treatment of moving blades 11 from tip to fillet is possible, wherein a simultaneous deep rolling of the pressure and suction sides of moving blades is provided to avoid a stress induced distortion.

One of the leading edge 13 facing the first processing ^¬ area 16, which is a main solidification range is processed by a first rolling tool with a desired ers ^¬ th compressive force. In order to avoid or residual stress cracks between the first processing area 16 and an adjacent untreated portion of the blade 11 to reduce, then a first processing ^¬ region 16 comprehensive second processing area 17 of ei ^¬ nem second roller tool, which reduced a opposite the first compressive force Pressure exerts hard-rolled. In this case, the second processing region 17 in particular comprises an edge zone 18 of the first processing region 16, so that the second processing section 17 facing away from the present case both in a direction of the leading edge 13, extends further in the direction of a blade root and in the direction of an upper edge 25 of the blade 11 than the first Bearbeitungsbe ^¬ rich sixteenth

This procedure is repeated with a third rolling tool and a fourth tool roll, wherein the pressure force exerted on the depending ^¬ stays awhile blade 11 is continually re ^¬ duced. The third processing region 19 or fourth processing region 20 in this case comprise an edge zone 21 or 22 of the respectively preceding processing region 18 or 19.

The residual stress cracks between the machining areas 16, 17, 19, 20 are the smaller the pressure differences between the individual rolling tools are, of which also can be used for a corresponding number of processing ^¬ areas only two or three or more than four, the more effective and reduced to the unprocessed area by a ge ^¬ wrestle pressure gradient. Due to the plastic deformations caused Ver ^¬ roller marks can thereby be reduced, and a smooth transition between areas processed to unprocessed portions of the blades 11 can be achieved.

The respective rolling tools are moved in the present embodiment, respectively in a meandering in the Fig. 4 schematically gezeig ^¬ th path of movement along the arrows PI and P2 with respect to the blades 11, wherein overlap ^¬ are just provided of, in particular greater than 60% between adjacent trajectories , A main direction of movement of the respective rolling tool may be from the upper Edge 25 or tip of the impeller 11 in the direction of the Schau ^¬ felfußes 26 or vice versa.

The second, third and / or fourth Bearbeitungsbe ^¬ rich 17, 19, 20 may comprise on the one hand the entire previous Bear ^¬ beitungsbereich 16, 17, 19 or only the edge zone 18, 21, 22 of the previous processing portion 16, 17, 19th Distances between the edge zones 18, 21, 22, 23 of the respective processing sections 16, 17, 19, 20 are present in Wesent ^¬ union constant, which may vary depending on the application.

In addition to the described order of use of the rolling tools, these can also be used in reverse order, wherein first the fourth Bearbeitungsbe ^¬ rich 20 is rolled with the lowest processing pressure and at the end of the first main bonding region 16 is firmly rolled with the first rolling tool.

In addition to the use of the inventive method for solidification in the field of blades of blade wheels of jet engines, the inventive method can in principle be used for solidification of surfaces of all components, which can be covered on both sides of a rolling ^¬ tool. In particular, thin-walled areas of jeweili ^¬ gen component can be treated with the inventive method. LIST OF REFERENCE NUMBERS

Jet engine

Bypass duct

intake area

blowers

Engine core

compressor means

burner

The turbine apparatus

paddle wheel

body

blade

leading edge

consolidation area

first processing area

second processing area

Edge zone of the first edit area Third edit area

fourth processing area

Edge zone of the second machining area Edge zone of the third machining area Edge zone of the fourth machining area Upper edge of the running wheel

blade

arrows

Claims

claims A process for mechanical edge zone solidification inner ^¬ half a component edge zone of a component (11) having we ^¬ nigstens a rolling tool, are inserted through the at least one rolling tool by means of deep rolling in at least a near-surface solidification area (14) of the construction ^¬ part (11), residual stresses, and wherein the at least one roller ^¬ tool is arranged during the deep rolling in each case a portion of the construction ^¬ part (11) between areas and two sides of the construction ^¬ part (11) are deep rolled at the same time, characterized denotes ge ^¬ that the component (11) of at least two rolling tools in the region of the solidification region (14) is firmly rolled, which during the deep rolling a mutually differing, each at least ^{approximately} approaching ^¬ constant compressive force on the component (11) ausü ^¬ ben. A method according to claim 1, characterized in that the component is a moving blade (11) of a paddle wheel (9) for a jet engine (1). A method according to claim 2, characterized in that the blade (11) is integrally formed with a wheel comprises ^¬. Method according to one of claims 2 or 3, characterized ge ^¬ indicates that the blade (11) in the region of a leading edge (13) is firmly rolled. Method according to one of claims 1 to 4, characterized ge ^¬ indicates that first a first Bearbeitungsbe ^¬ rich (16) of the component (11) in a first machining ^¬ processing step with a first compressive force of a first rolling tool and then a second, at least a rim region (18) of the first machining ^¬ processing region (16) of the component (11), at least certain regions as ^¬, in particular completely, extensive machining ^¬ processing area (17) of the component (11) in a second Be ^¬ processing step with respect to the first pressure ^{¬ is} reduced by a second rolling ^tool force reduced second pressing force. A method according to claim 5, characterized in that at least one further, at least one Randzonenbe ^¬ rich (21) of the second processing area (17) of the Bau ^¬ part (11) at least partially, in particular fully ^¬ constantly, comprehensive processing area (19, 20) of Component (11) is rolled with a respect to the second pressure force respectively reduced pressure force. The method of claim 6, characterized in, be that the rolling tools in such a way relative to the component (11) ge ^¬ leads, that a distance between the edge zones (18, 19, 22, 23) of the respective processing sections (16, 17, 19, 20) of the Component (11) over the course of which is at least approximately constant. A method according to claim 6, characterized in that the rolling tools in such a way relative to the component (11) ge ^¬ leads are that a distance between the edge zones (18, 19, 22, 23) of the respective processing sections (16, 17, 19, 20) of the component (11) varies over the course thereof. 9. The method according to any one of claims 1 to 4, characterized ge ^¬ indicates that first a first Bearbeitungsbe ^¬ rich of the component (11) in a first processing step ^¬ with a first compressive force of a first rolling tool and then a second partly rolled, in particular is completely hardened by rolling from the first Bear ^¬ beitungsbereich encompassed processing region of the construction ^¬ part (11) in a second machining step with respect to the first pressing force increased second pressure ^¬ force from a second roller tool. 10. The method according to claim 9, characterized in that at least one further processing region of the construction ^¬ part (11) is firmly rolled with a comparison with the second compressive force he ^¬ increased pressure force, whereby this is at ^¬ least partially covers, in particular completely by the second processing section , 11. The method according to any one of claims 1 to 10, characterized ge ^¬ indicates that the deep rolling process in particular je ^¬ Weil in a meandering movement of the respective rolling tool relative to the component (11) is performed.