CN1074692C - Closed forging technology and rotary step type forging press - Google Patents

Abstract

A forging press includes a die set having a stationary die, a movable die and an exterior constraint. The movable die has a base level region lying generally in a workpiece plane perpendicular to the press axis, and three rotationally symmetric segments raised above the base level region. Each of the segments forms an angular segment of a disk having an included segment angle and that is angularly separated from the other segments. A press mechanism includes a axial drive operable to move the movable die in a direction parallel to the press axis, and an indexing drive operable to rotate the movable die about the press axis by an indexing rotational angle.

Description

Closed forging technology and rotary step type forging press

The present invention relates to a kind of forging method and a kind of forging press that is used for general axis symmetry product, in this forging press, plain shaft symmetry product forges with a kind of step-by-step system.

In forging process, in two or more forging dies, workpiece is suppressed by a kind of machine that is called forging press.The shape that the workpiece plastic deformation becomes is by the shape of forging die and the size decision of press power.Forging may be finished at a single stroke of compressing into, and perhaps may exist a plurality of strokes of compressing into little by little workpiece deformation is arrived the desired shape of product.

Forging operation makes workpiece attenuation on forced direction, and causes workpiece to stretch along vertical plane, thereby workpiece is deformed to the shape that finally is swaged into.The shape that workpiece finally is swaged into must be different from last shape of product.Because in general, clinging to workpiece, accurately to forge into final desired shape of product be impossible or unpractical.The shape that finally is swaged into and the degree of approximation of final desired shape of product have determined the difficulty of forging operation on some degree.The whole plan view of workpiece surface is forged equably simple relatively, this is called pancake forging.Yet in relating to the common situation that final requirement is a complex-shaped workpieces, pancake forging residue lot of materials need be carried out machining to reach the accurate final shape of product that required.In a kind of more advanced forging method, workpiece is forged into the shape (NNS) of nearly end form, this shape approximation is in the shape of final workpiece, but deliberately make size big slightly, remove enough materials to be adapted at distortion and the final machining surplus in the heat treatment process so that can carry out ultrasound examination.In this NNS forging method, the amount of metal that needs machining to fall is relatively little.NNS forges obviously need more need creativity than pancake forging in the design Forging Technology.

In the various operations that forging is widely used in, to produce the product of smallclothes or big part.In order to make workpiece deformation, forging press must provide needed power.The production of big part is especially complicated, because the big more then needed forging force of product is big more.Thereby, need bigger, more expensive forging press to finish forging.Just as mentioned, NNS forges usually needs bigger forging force than pancake forging, and therefore needs bigger forging press.

In some cases, need to produce a kind of product, the size of its structure and material be existing forging press ability can not produce.Forge this product, well-known, can adopt the open die forging operation that workpiece is carried out step-by-step movement and forge.In the step-by-step movement open die forging, the design of forging die and the operation of forging press are: only some is forged workpiece at any one time, and after each part was forged, workpiece moved with respect to forging die stepping ground to workpiece, and final realization is to the forging fully of whole work-piece.Regrettably, the shape that all can not obtain nearly end form to most of products is forged in open die forging and step-by-step movement die sinking, and this is because free part can extend into arbitrary dimension and shape on the workpiece, rather than a kind of shape of nearly end form.

In the portion application, workpiece is swaged into a kind of axial symmetry turbine disc that is used for large-scale continental rise gas turbine.The diameter of this turbine disc is 70～96 inches or bigger.Their adopt Ni-based or the iron-based high-alloy steel is made, even and can not be become the profile of desired nearly end form shape by forging on the forcing press with 50,000 tons of abilities.The nearly end form shape of this axial symmetry, size and the final desired mechanical performance of turbine disc are quite strict.For this disk, existing step-by-step movement FMT can not satisfy these requirements.

Therefore, need a kind of improved method to forge large-scale axial symmetry product.The present invention can address that need, and corresponding characteristics further are provided.

The technology that the invention provides a kind of step type forging press and be used to produce the nearly end form shape of large-scale axial symmetry forging.The shape of forging, size and mechanical performance are applicable to accurate operation, for example the final machining that large-scale continental rise turbine disc is carried out.In final forging operation, forging and pressing in the stroke each time, only some contacts with forging die workpiece, and therefore, the size of workpiece on the other hand may be bigger than the size that the ability of existing forging press can be forged.With respect to existing method, the amount of the last machining that product is required has reduced significantly.The latter is very important, is workpiece material consumption because forge a major part of cost, and this workpiece is Ni-based high-alloy steel.Reducing needs the quantity of material of machining also just to reduce production cost of products.

According to the present invention, it is the operation with the axisymmetric round-disk shape workpiece on plan view surface that the method that workpiece forges can be used for general original workpiece.This method comprises at first forges on the whole substantially plan view surface of original workpiece, and then the workpiece that is swaged into is for the first time carried out step-by-step movement forge, and makes it to become final forging shape.In the forging operation first time, adopt a kind of forging die (non-step-type) that covers whole plan view surface basically that original workpiece is forged.The inner radial part of workpiece is preferentially forged becomes to be roughly final forging profile, but the radially outer of workpiece part is not swaged into final forging profile.In step-by-step movement forging process subsequently, the radially outer part of workpiece is swaged into to stepping at first and is final forging shape, and do not have tangible workpiece inner radial partly to be out of shape, though in the step-by-step movement forging process, may there be less relatively inner radial distortion in workpiece.

The technology of the present invention adopts closed die forging, compares with common non-step-by-step movement closed die forging technology, can forge radially bigger, be axisymmetric product substantially.The forging ability of the maximum of forging press is determined by the maximum product size that the closed die forging forging press may forge.Adopt the feasible product that can forge bigger (but others are identical) with same forcing press and forging condition of step-by-step movement closed die forging.According to this aspect of the invention, the step was poly-below the method for forging large-scale workpiece comprised: dispose a forging press, the maximum forging and pressing ability of this forging press is enough to forge with closed die forging and has the axial symmetry product that utilizes the final size maximum that non-step-by-step movement forges.This method also comprises provides axisymmetric workpiece, and under certain forging condition, adopts closed die forging that workpiece is carried out step-by-step movement in forging press and forge, and making it distortion becomes the step-by-step movement forging product.This product has the step-by-step movement forging final size bigger than the non-step-by-step movement forging final size of maximum.In order to do corresponding comparison, for example material, temperature, forging and pressing amount and geometric similarity are all the same for all other forging condition, have only the size of workpiece and mould to have any different." size " refers to from the radial dimension of symmetry axis to external pelivimetry.

Step-by-step movement is forged, preferably the mold closing step-by-step movement is forged, finally forge shape so that form the nearly end form be similar to desired final products, but size will be bigger slightly so that carry out ultrasound examination, and remove unnecessary material to adapt to distortion in the heat treatment and final machining.Existing step-by-step movement die sinking forging press and technology can not be produced nearly end form shape in this application, thereby need a kind of mold closing forging press of development and technology, be used for forging that in beginning forger preface, be swaged into, axisymmetric, be generally discoidal workpiece.

According to this aspect of the invention, but forging press comprise fixed die and have dynamic model relative along the forcing press axis but in a certain distance apart from one another movable die face with the fixed die die face with fixing die face.Fixedly die face can be flat, perhaps can be to copy out according to the shape of laying the surface of the work that mould faces.Movable die face comprises datum level and at least one secter pat that is positioned at perpendicular to the surface of the work of forcing press axis, preferably just in time is three rotational symmetric secter pats that protrude from the datum level.Each secter pat comprises parallel with the forcing press axis and a fan-like pattern of the disk of a covering of the fan angle is arranged with respect to the forcing press axis.Existence is more than one secter pat, each secter pat and other secter pat certain angle of being separated by.The attaching means that also has an outer annular to extend, but extend to prevent that workpiece produces radially when workpiece compresses between fixed die and dynamic model.That is to say that forging is closed die forging rather than open die forging.External constraint is preferably an annular outer wall, and it can separate with fixed die or integrate.But the space boundary that fixed die dynamic model and external constraint spare surrounded hold the volume of workpiece.Pressure mechanism comprises axial actuating mechanism, moves being parallel on the forcing press axis direction but can handle dynamic model; With the transposition driving mechanism, specify the anglec of rotation around one of forcing press axis rotation but can handle dynamic model.Though when but dynamic model is return and no longer contact with workpiece, the rotation and axially-movable may be simultaneous, but moving axially of dynamic model with rotatablely moving of transposition driving mechanism only in the conversion regime when but dynamic model contacts with workpiece, just can carry out.

Generally speaking, forging press comprises a mold, and this mold comprises fixed mould with relative with fixed die along the forcing press axis, but moveable die in a certain distance apart from one another.Also have a ring-type to extend workpiece volume external constraint spare on every side.But the space boundary that is surrounded by fixed die dynamic model and external constraint spare its workpiece volume that can be contained in.But one of fixed die and dynamic model have the shape of a projection in the above at least.The employed mechanism that compresses into is with recited above identical.

In most preferred embodiment, but on the datum level zone of dynamic model, there is the secter pat projection of three or more symmetries.Though have some partial lateral and/or flowing accidentally towards inside to fill up the shape that secter pat is limited, but with the mating reaction of the external constraint spare that forms closed die forging under, these secter pats partly are out of shape workpiece, thereby workpiece flows towards radially outer direction substantially.They also partly produce distortion to cause flowing of metal at the workpiece that does not have secter pat.

The secter pat side that carries out the transition to the datum level zone on each side by each secter pat preferably has about 45 °～60 ° oblique angle and tilts.Do not having under the situation at this oblique angle, may be created in fold or the crackle that to eliminate in the follow-up forging and pressing stroke in the exterior lateral sides of workpiece.

In the operation of step type forging press, workpiece is loaded into and holds the workpiece part.Forging press forges and presses in the stroke part to workpiece in the axial first time and forges.The power that acts on the forging die is released, and simultaneously, mould is return.But the transposition driving mechanism is handled the anglec of rotation of dynamic model around an appointment of forcing press axis rotation, and axial actuating mechanism provides another time forging and pressing stroke.When needs forge whole work-piece, will repeat this process.

This forging press and forging method have technically had a major progress what forge large-scale axial symmetry product.The product that forges has nearly end form profile and bigger than the product that adopts existing mold closing forging press ability to produce.The product that forges is swaged into the profile of nearly end form, and this has just reduced total material consumption and machining requirement, thereby has reduced product cost.

Fig. 1 is best Forging Technology schematic flow sheet;

Fig. 2 is the front view of original workpiece;

Fig. 3 is the front view of the workpiece after for the first time non-step-by-step movement is forged;

Fig. 4 is the front view that step-by-step movement is forged the workpiece after finishing;

Fig. 5 is the cutaway view of forging equipment of the present invention;

Fig. 6 is the decomposition diagram of the forging equipment of Fig. 5;

But the vertical view of the dynamic model that Fig. 7 is the 7-7 in Fig. 5 to be cut open;

But the cutaway view of the dynamic model that Fig. 8 is the 8-8 in Fig. 5 to be cut open;

The front view of the Large-scale Forging press that but Fig. 9 is a dynamic model to be return;

But Figure 10 is the front view during as its dynamic model contact workpiece of forging press of Fig. 9;

Figure 11 is the cutaway view that is swaged into the turbo blade of nearly end form shape;

Figure 1 shows that the optimum implementation of technology of the present invention.Label 80 is original workpiece.Original workpiece can be made by any wrought metal, for example steel, aluminium alloy, iron-based high-alloy steel, Ni-based high-alloy steel or titanium alloy.Original workpiece is of a size of like this: it contains enough amounts of metal makes and can be deformed into final forging shape at metal flow to final forging shape part.The design of original workpiece can be adopted any known metal flow designing technique.For the axial symmetry land-based turbines disk that the inventor especially is concerned about, as shown in the figure, its final diameter is approximately 70～96 inches, thickly is about 20 inches, and the original workpiece 90 of its axial symmetry is about 31 inches of diameter, high about 65～75 inches cylinder.Original workpiece 90 has original plane view surface 92, and it is the surface of the workpiece end that forging die contacted in the forging operation for the first time.

Label 82 adopts general non-step-by-step movement Forging Technology that original workpiece is carried out the first time and forges.In the forging operation first time, when being out of shape, forging die covers whole plan view surface 92 basically.Forging die can be close die or open die, but close die preferably.Forging die shape in forging for the first time is flat basically, though the cross section may have the shape of regulation in the middle.Along with the master metal critical path is mobile to outwards, workpiece is towards final desired warpage.In order to limit the shape of the workpiece that is swaged into, in the scope of the forging operation first time 82, also has the heating again of a plurality of sub-operations and workpiece.Mould preferably is deformed into its net shape with the inner radial 94 of workpiece 90.The hub portion of regulation as shown in Figure 3.Yet, do not attempt the exterior section radially 96 of workpiece 90 is swaged into its net shape.Be open die if forge for the first time, then exterior section 96 radially is deformed into the shape of point image sphere, as shown in Figure 3, if close die then is a more fixed shape.It is impossible often workpiece exterior section 96 radially to be swaged into its net shape, because the forging and pressing scarce capacity that forging press has becomes desired nearly end form shape to cause the metal flow.

Forge for the first time 82 finish after, then label 84 forges for will workpiece being carried out step-by-step movement with closed die forging.Up to the present required step-by-step movement forging equipment and technology also do not have available, below a kind of step type forging press and the technology discussed for inventor research.In step type forging press, the part on the plan view surface of a forging die contact workpiece 90.It would be desirable that most forging power all concentrates on the fan loop section of exterior section radially 96 of workpiece 90.Though may be to interior section 94 some forging radially, interior section 94 radially is subjected to forging power and distortion seldom relatively.When step-by-step movement forging process 84 was finished, as shown in Figure 4, workpiece was deformed into nearly net shape products, and this product has main by the exterior section radially that is swaged in the operation 82.This method is best, but existing method also is feasible under other conditions, as the operation 82 that is used to limit the net shape of exterior section 96 radially is step-type, and the operation 84 that perhaps is used to limit the net shape 94 of interior section radially is step-type.

Label 86, for the product with net shape is heat-treated, this step is selectable, but this step is preferably arranged.

Existing non-step-by-step movement is forged for the first time with the technology of step-by-step movement closed die forging combination is used for large complicated workpiece is forged into nearly end form shape by development.This technology is not to be used for replacing all general FMTs, because it implements more expensive than general non-step-by-step movement forging cost.Yet, because the compacting ability of forging press or the restriction of other reasons, general Forging Technology can not obtain finally to forge disc-shape, so this method is practical, and can obtain the nearly end form structure of the sort of large forgings, and realized the inevitable saving in material, machining and other costs.

As has been noted, the step-by-step movement forging equipment is used for above-mentioned technology and other application by development.But Figure 5 shows that forging press 20 with fixed die 22 and dynamic model 24.Counterdie is depicted as fixed die 22, but and patrix is depicted as dynamic model 24, can certainly arrange on the contrary.Because workpiece is placed on the counterdie, so counterdie is a fixed die 22.Fixed die 22 has fixedly die face 26, but dynamic model 24 has movable die face 28.Fixedly die face 26 is relative along forcing press axis 30 with movable die face 28, but in a certain distance apart from one another.It is axisymmetric that mould 22 and 24 is preferably usually, though their surface may not be axisymmetric and may replace non-step-type characteristics.Workpiece 32 is placed between mould 22 and 24.

The radially outer attaching means 34 of annular wall extension form extends around the circumference of workpiece.Mould 22 and 24 and annular wall extension 34 define the mold closing workpiece accommodated position 36 that can all hold workpiece 34, annular wall extension 34 can be the ring-type annulus that separates with fixed die 22 or become one with fixed die 22.From Fig. 5, before the beginning forging operation, workpiece can contact the inside surface 38 of annular wall extension 34, also can not contact the inside surface 38 of annular wall extension 34.In forging process, workpiece 32 is compressed on the direction that is parallel to the forcing press axis, and owing to flowing radially outward of metal produces radial expansion, stretch out the inside surface of wall 34, so just limited workpiece 32 further radial expansion until touching annular.

This forging in the defined volume scope is the essence of closed die forging, and becomes the significant advantage that is better than open die forging.In closed die forging, metal is plastic deformation radially outwardly, thereby forces the metal flow to become the shape that mould and/or wall extension limit.On the other hand, in open die forging, the outside flow of metallic radial does not suffer restraints so that metal when forging along the path of resistance minimum flow and be not deformed into the shape that is limited radially outwardly, yet this respect is necessary for producing nearly net shape products.Therefore, closed die forging has obtained open die forging institute can not obtainable result, comprises the nearly end form structure with the surface configuration that is limited by forging die.

Figure 6 shows that mould 22 and 24, the partial sectional view of annular wall extension 34 and workpiece 32.

But dynamic model 24 is movable being parallel on the forcing press axis direction, and moves to the fixed die direction in the stroke in forging and pressing, as the axial arrow indication of Fig. 5, and in the mode of appointment around 30 rotations of forcing press axis, as rotation arrow 42 indications.(but dynamic model also can move in the opposite direction) but when dynamic model contacts with workpiece 32, forging and pressing stroke direction on and direction of rotation on motion can only finish a motion sometime.Therefore these motions are alternative, and this will be discussed below.When but dynamic model is return and no longer with when workpiece 32 contacts, axial motion and rotatablely move and can finish simultaneously.But dynamic model 24 moves by compressing into mechanism 44, and this compresses into mechanism 44 two kinds of motions 40,42 are provided, and will discuss a kind of best mode below.

Fixedly die face 26 is flat substantially.Also can replace a kind of imitated shape.In forging process, fixedly the shape flat or that copy of die face is pressed into (bottom surface of workpiece among the figure) on the side surface of workpiece of being faced.

But on dynamic model, be provided with circlewise, two kinds of shape type are arranged.These features in Fig. 5-8 as can be seen.One of feature is to have a fan-shaped datum level zone 46 at least, preferably has three at least, have only three best, these fan-shaped datum level zones 46 are flat and usually with parallel perpendicular to the workpiece planarization of forcing press axis 30 basically.Another feature is the secter pat 50 that equal number is arranged, and their upper surface is flat or profiling, and parallel with workpiece planarization 48.As shown in Figure 8, the plane of that secter pat upper surface 52 be from datum level zone 46 towards fixing die face 26, and vertically be provided with along forcing press axis 30.In other words, secter pat 50 is given prominence on datum level zone 46.The quantity in datum level zone 46 is consistent with the quantity of secter pat 50.

At least one secter pat 50 must be arranged, if the secter pat more than is arranged, but the best datum level zone with same quantity of these secter pats is provided with symmetrically on the dynamic model surface.That is to say that if having two, three, four or more secter pat, when from plan view, they should be to arrange axisymmetrically, to reduce the out-of-balance load of forging press as far as possible so.If secter pat is lower than three, will consider that then the load of secter pat may be too high, and forcing press is subjected to out-of-balance load.For the forcing press of the used especially big ability of the inventor 50,000 tons of forcing presses for example, obtain the service life of desired shape of product and structure, machine and stability and workman's safety, then consider load asymmetric is very important.For the secter pat 50 that has more than three, relative more and more narrow with the arc chord angle that secter pat is corresponding.Therefore they trend towards with more causing the invalid plastic deformation of workpiece as nip metal rather than make flow of metal by forging of cookie cutter.Consideration in these theory and practice causes and will adopt three secter pats 50 and three staggered datum level zones 46 (as shown in Figure 7) as optimal selection, is feasible in some cases though adopt die face still less or more secter pat 50.

Secter pat 50 keeps at a certain distance away around movable die face 28 and disposes symmetrically, the corresponding segment angle A of single secter pat.One of datum level zone 46 is arranged between each secter pat 50, and relative datum level zone angle C.The summation of all secter pat angle A, the summation that adds used datum level regional perspective C is 360 °.

Folded secter pat angle A preferably is approximately between 45 °～65 °.If A is in fact littler, then mould may be trapped in the workpiece owing to the effect of above-mentioned round bottom shaped steel system caisson.If in fact bigger, then mould becomes and more resembles common mould flat or profiling, and the effect of the torsional moment of the press capacity of step-by-step movement Forging Technology will be very little.Angle C is determined by the quantity of angle A and secter pat.

Fig. 7 and the geometry that Figure 8 shows that secter pat 50.Secter pat 50 is pie bulks, and when as shown in Figure 7, is the secter pat of annular.In the cutaway view of Fig. 8, secter pat 50 comprises the secter pat side 58 of an inclination, and it is between the upper surface and datum level 46 of secter pat 50.The thin slice that is rather narrow also can be seen in the side 58 of these secter pats in the plane of Fig. 7.The side of secter pat becomes inclination angle D with the upper surface of secter pat.Inclination angle D preferably is approximately 45 °～60 °.If inclination angle D is in fact little than 45 °, then the angle A of secter pat is in fact extended, and the torsional moment effect of press capacity will reduce.If inclination angle D is in fact big than 60 °, then can be observed and nip or the effect of round bottom shaped steel system caisson.Will occur the defective of fold and crackle in step-by-step movement is forged, this will be discussed below.In a single day these defectives generate, and just can not eliminate fully in follow-up forging or other operations.But workpiece 32 is placed between fixed die 22 and the dynamic model 24 to adopt step-by-step movement forging process 84 or other operations to forge.When for the first time forging and pressing stroke, handle and compress into mechanism and make movable die face 28 mobile on the direction of fixing die face 26.The pressure state that workpiece is mentioned in the above is distortion down.It is reverse to compress into mechanism, but with dynamic model from workpiece 32 contact conditions return.Manipulation is compressed into mechanism 44 so that but dynamic model is rotated some predetermined values in a kind of transposition campaign around the forcing press axis.Select the rotation value relevant with the size of performance, shape, desired restriction and the workpiece of material.The rotation value of each transposition campaign is less than angle A.Material is thick more, and the transposition rotation is just more little.As optimal cases, transposition rotation value generally is approximately 40 °～60 °, and under a kind of typical situation, it is 55 ° that three secter pats and angle A are arranged, and then Zui Jia transposition rotation value is approximately 40 °.Rotatablely move finish after, forging and pressing in the stroke for the second time, compress into mechanism 44 dynamic model moved towards fixing die face 26 directions but handle.Behind the workpiece deformation, but compress into mechanism with dynamic model 24 from returning with contacting of workpiece 32.But manipulation is compressed into mechanism with rotation dynamic model 24.These operations are repeated repeatedly to finish forging.For optimal cases: it is that 55 °, forcing press transposition rotation value are 40 ° that three secter pats, angle A are arranged, and the summation that requires to forge strokes for three times can be finished a kind of distortion.Repeatedly distortion can be used for thick forging and the high forging of workpiece material intensity.In forging process, workpiece is in the condition of high temperature usually, and can cooling in forging operation.In forging operation, when needs, can heat again workpiece, obtain specific microstructure with the flow stress that reduces it with in workpiece.

Top argumentation has illustrated that the step type forging press of common form is applicable to the charger of any roof pressing type.What be concerned about for the inventor's application is to adopt 50,000 tons of vertical forging presses of mold closing to make the large-scale impeller that is used for gas turbine with Ni-based high-alloy steel or titanium alloy forging.Size that workpiece is huge and huge forging and pressing load cause the special consideration of compressing into mechanism to mould.

Referring to Fig. 9 and Figure 10, upper bearing plate 101 is moving components of forging press.Basal plane 102 is fixed by bolt and upper bearing plate, and ring 103 is fixing by bolt and basal plane 102, and a swivel bearing plate 104 is fixed in the ring 103 rotatably.Mold jockey 105 is fixing by bolt and swivel bearing plate 104.Patrix 106, but corresponding to above-mentioned dynamic model 24, fix by bolt and patrix jockey.Swivel bearing plate 104 is fixed in the centralizer 108, and this centralizer can make swivel bearing plate 104 rotate around forcing press axis 30 and can allow swivel bearing plate 104 move up and down in ring 103.Centralizer 108 prevents that swivel bearing plate 104 from radially moving with respect to forcing press axis 30 works.

Lower support plate 151 is supporting bed die 152, and corresponding to above-mentioned fixed die 22, this mould comprises a bed die 152 and an annular distance 154.Bed die 152 and annular distance 154 form the counterdie cavity, and workpiece can be placed in this counterdie cavity.

In returning state, the aperture position of Fig. 9 forcing press, rotary table are arranged on the support plate 109 that is fixed in ring 103 inside.These support plates 109 can allow rotary table rotate easily around forcing press axis 30 under the effect of hydraulic cylinder, thereby finish the rotary indexing motion.A kind of steadily rotatablely moving reliably, relatively rapidly is achieved, thereby improved the production capacity of forging press and made that also the workpiece to heat carries out rapid forge when workpiece is still enough warm.Even making, said method in Large-scale Forging press mechanism, also can realize rotation.

As shown in figure 10, during contacting with workpiece 155 when patrix 106, swivel bearing platform 104 is upwards pushed away support plate 109 and against the upper surface of basal plane 102.The CONTACT WITH FRICTION of rotary table 104 and basal plane 102 has limited rotation.As shown in figure 11, adopt the profiling mould for example mould 106 and 153 can workpiece be forged by closed die forging and become nearly end form shape.The pattern 160 that ordinary flat is forged generally is provided as corresponding flat-die by open die forging, and this flat-die is covered by on the workpiece of mould 162 that nearly end form forges and final machining, and this nearly end form mould is provided as profiling mould 106 and 153.Any unnecessary material must be cut and machine away to produce final products in each situation.No matter for being that nearly end form forges or pancake forging, final machining all is inevitable.Yet, final machining for nearly end form closed die forging than pancake forging lack many.The shadow region represent to exceed from nearly end form forging must machining fall and excess stock that must machining is fallen from flat die sinking forging in this case, is approximately 30% of flat forging volume.When workpiece is made by the Ni-based high-alloy steel of costliness, for example in the situation of high speed continental rise gas turbine, difference between the waste material cost of charging cost and unnecessary Ni-based high-alloy steel material may account for the higher ratio of product totle drilling cost, as is about 10～20% or more.Therefore the present technique method can obtain variable cost savings and the fixing cost savings in material cost, the workpiece that forges under can be under than other situation lower pressure.

With the product of Ni-based high-alloy steel manufacturing such as turbo blade, generally to when being in high temperature, workpiece carry out.For example will forge the large-scale blade that is used for land-based turbines, the diameter of its final blade is 70～96 inches, heavily exceedes 15,000 pound, made by Ni-based high-alloy steel such as Inconel706, workpiece will be heated in heating furnace on its solid melting temperatur, is generally 1825 °F.The crystallization workpiece is transferred in the forging press again, forges workpiece then.Workpiece is cooled to solid melting temperatur through a period of time, is lower than solid melting temperatur then.When work-piece cools, required forging force increases, and its flow stress also increases, but the step-by-step movement forging process makes forging to proceed down.Final step-by-step movement forging stroke is preferably in when being about 1750 °F on the solid melting temperatur and carries out, to obtain relatively little crystallite dimension ASTM3～5.Metallographic studies show that structure with step type forging press and as shown in Figure 1 technology gained is with the same basically with Technology for Heating Processing (but the very large-scale workpiece that this method can not successfully be concerned about most this paper carries out forging) with general forging.Above argumentation especially at Incnel706, a kind of preferred material that the present invention adopts.For other materials, then may need other technology, belong within the scope of the present invention.

Though the present invention combines certain embodiments and described, can make various improvement and raising and do not deviate from the spirit and scope of the present invention.Therefore, claims of being not limited to of the present invention.

Claims (19)

1. the method for a forging workpiece comprises operation: the original workpiece that the view surface with plane is provided; Adopt the closed die forging mould that the forging of workpiece step-by-step movement is become final forging shape, described closed die forging mould has an external constraint spare around the extension of workpiece periphery, extend diametrically with the volume that prevents workpiece when workpiece being carried out the step-by-step movement forging, it is characterized in that, but described step-by-step movement forging process is included between each time stroke that a single dynamic model axially forges and presses repeatedly along the direction that is parallel to the forging press axis, but described single dynamic model is rotated with respect to a single fixed die stepping ground around the forging press axis, but described single dynamic model become to face mutually but the relation of space in whole stepping rotation process with single fixed die.

2. as the method in the claim 1, it is characterized in that, also comprise an additional process: after original workpiece operation is provided and before the step-by-step movement forging process, non-step-by-step movement is carried out on the whole plan view surface of original workpiece forge.

3. as the method in the claim 2, it is characterized in that, non-step-by-step movement is forged and is comprised step: with forging die original workpiece is forged earlier, this forging die covers whole plan view surface substantially, finally forge shape so that workpiece interior section is radially become it by forging like this, and workpiece radially outer part is not become its final shape of forging by forging.

4. as the method in the claim 3, it is characterized in that the step-by-step movement forging process comprises step: the workpiece radially outer is partly forged becomes its final forging shape, and does not change the inner radial part of workpiece substantially.

5. as the method in the claim 1, it is characterized in that step-by-step movement is forged and comprised step: workpiece is forged becomes a kind of nearly end form turbo blade.

6. as the method in the claim 1, it is characterized in that the step-by-step movement forging process comprises step: a forging press is provided, and its forging scarce capacity becomes nearly end form shape to adopt non-step-by-step movement Forging Technology that workpiece is forged; Then the workpiece step-by-step movement being forged becomes its last shape of forging.

7. the method for claim 1, it is characterized in that, but described dynamic model and described fixed die wherein at least one has the secter pat of at least one projection on a datum level, each secter pat includes the segment angle of a disk, each secter pat and the separated certain angle of other secter pat.

8. the method for claim 1, it is characterized in that, described step-by-step movement is forged and is comprised the step that a forging press is provided, described forging press comprises: a mold, but this mould comprises a fixed die and dynamic model, but it is relative with fixed die along the forging press axis to be somebody's turn to do dynamic model, but in a certain distance apart from one another; External constraint spare around the extension of workpiece volume annular extends diametrically but this attaching means prevents the volume of workpiece when workpiece forges between fixed die and dynamic model, but at least one fixed die and the lobed in the above shape of dynamic model; Compress into mechanism for one, but but comprise that being used to handle dynamic model is being parallel to the axial drive means that moves on the forging press axis direction and is being used to handle the step drive device of dynamic model around a predetermined anglec of rotation of forging press axis rotation.

9. forging press comprises: a mold, but this mould comprises a fixed die and dynamic model, but should dynamic model relative with fixed die along the forging press axis, but in a certain distance apart from one another; External constraint spare around the extension of workpiece volume annular extends diametrically but this attaching means prevents the volume of workpiece when workpiece forges between fixed die and dynamic model, but at least one fixed die and the lobed in the above shape of dynamic model; It is characterized in that, comprise that is also compressed into a mechanism, comprise that but but being used to handle dynamic model is being parallel to the axial drive means that moves on the forging press axis direction and is being used to handle the step drive device of dynamic model around a predetermined anglec of rotation of forging press axis rotation, when rotated, but described fixed die and dynamic model keep mutually in the face of but the relation of space.

10. as the forging press in the claim 9, it is characterized in that this imitation profile is included in a radially-protruding imitation profile side between imitation profile and the adjacent domain, and it is characterized in that this profiling side has 45 °-60 ° inclination angle.

11. as the forging press in the claim 9, it is characterized in that external constraint spare comprises a ring-type wall extension, this wall extension has with respect to the substantially invariable radius of forging press axis.

12., it is characterized in that imitation profile comprises as the forging press in the claim 9:

A datum level, this datum level generally are positioned on the workpiece planarization perpendicular to the forging press axis; And

At least three rotational symmetric secter pats that are raised on the datum level, each secter pat comprises the segment angle of a disk, this segment angle has the circle core shaft that is parallel to the forging press axis and has a fan-shaped angle, each secter pat and the separated certain angle of other secter pats with respect to the forging press axis.

13. as the forging press in the claim 9, it is characterized in that fixed die has a fixedly die face, moveable die have one along the forging press axis with fixedly die face is relative, but movable die face in a certain distance apart from one another, and this movable die face comprises: generally be positioned at perpendicular to the datum level on the workpiece planarization of forging press axis, and the secter pat of at least one projection on datum level, each secter pat comprises secter pat and the secter pat angle with respect to the forging press axis that has an angle on the disk with disk axis parallel with the forging press axis, and each secter pat separates certain angle with other secter pats.

14. as the forging press in the claim 13, it is characterized in that, between the contiguous datum level of each secter pat and annular, a secter pat side of radially extending is arranged, and 45 °-60 ° at the inclination angle that has with respect to workpiece planarization, the side of each secter pat wherein.

15. the forging press as in the claim 13 is characterized in that, external constraint spare comprises an annular wall extension, and this wall has one with respect to the substantially invariable radius of forging press.

16. the forging press as in the claim 13 is characterized in that, folded segment angle is between 45 °-60 °.

17. the forging press as in the claim 13 is characterized in that, the predetermined anglec of rotation is between 45 °-60 °.

18. the forging press as in the claim 13 is characterized in that, three secter pats are just in time arranged.

19. the forging press as in the claim 13 is characterized in that, three secter pats are just in time arranged, folded segment angle is 55 °, and the predetermined anglec of rotation is 40 °.

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