EP0299948A2 - Procédé et machine de forgeage pour la fabrication de corps composites - Google Patents

Procédé et machine de forgeage pour la fabrication de corps composites Download PDF

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Publication number
EP0299948A2
EP0299948A2 EP88890141A EP88890141A EP0299948A2 EP 0299948 A2 EP0299948 A2 EP 0299948A2 EP 88890141 A EP88890141 A EP 88890141A EP 88890141 A EP88890141 A EP 88890141A EP 0299948 A2 EP0299948 A2 EP 0299948A2
Authority
EP
European Patent Office
Prior art keywords
workpiece
deformation
tools
truncated cone
layer
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.)
Ceased
Application number
EP88890141A
Other languages
German (de)
English (en)
Other versions
EP0299948A3 (fr
Inventor
Hans Dr.-Ing. Hojas
Franz. Ing. Hildebrand
Walter Kroissenbrunner
Bruno Dipl.-Ing. Hribernik
Werner Dr.-Ing. Mitter
Günter Dipl.-Ing. Preininger
Robert Dipl.-Ing. Bauer
Josef Sonnleitner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Boehler GmbH
GFM Gesellschaft fuer Fertigungstechnik und Maschinenbau AG
Original Assignee
Boehler GmbH
GFM Gesellschaft fuer Fertigungstechnik und Maschinenbau AG
Boehler GmbH Germany
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Boehler GmbH, GFM Gesellschaft fuer Fertigungstechnik und Maschinenbau AG, Boehler GmbH Germany filed Critical Boehler GmbH
Publication of EP0299948A2 publication Critical patent/EP0299948A2/fr
Publication of EP0299948A3 publication Critical patent/EP0299948A3/fr
Ceased legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/17—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by forging
    • B22F3/172—Continuous compaction, e.g. rotary hammering
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J5/00—Methods for forging, hammering, or pressing; Special equipment or accessories therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21J—FORGING; HAMMERING; PRESSING METAL; RIVETING; FORGE FURNACES
    • B21J7/00—Hammers; Forging machines with hammers or die jaws acting by impact
    • B21J7/02—Special design or construction
    • B21J7/14—Forging machines working with several hammers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
    • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
    • B22F7/08—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools with one or more parts not made from powder

Definitions

  • the invention relates to a method for producing composite rods according to the preamble of patent claim 1. Furthermore, the invention relates to a radial forging machine according to the preamble of patent claim 8.
  • Composite rods consist of two or more materials, which have different mechanical and / or chemical properties and are preferably used in machine, apparatus and tool construction, etc., if several different stresses occur on the part at the same time.
  • the aim of the invention is to create a method with the multi-layer composite rods made of solid and / or powdery raw material components to achieve a perfect metallic bond between the material layers or an optimal composite structure, a practically 100% density of the products, a required dimensional accuracy and a high output can be produced.
  • the outer layer of the composite rod is made from metal powder, encapsulation is required. If the composite steel is to be produced from two metal powders of different compositions, these powders should preferably be separated by a thin tubular sheet insert. This sheet metal insert must form a metallic bond with both materials or be able to represent a binding aid. The thickness of the separating plate is significantly reduced during the deformation of the primary material.
  • the gap between the workpiece parts and / or the filled powder is (are) subjected to a vacuum and / or protective gas treatment on the primary material body, and then heated to the deformation temperature.
  • Precompaction e.g. of the powder
  • preforming can also be carried out beforehand.
  • FIG. 1 shows a schematic representation of the circular forging by radial forming, a) hammers with a flat track (flat hammers), b) hammers with a curved track (round hammers); Fig. 2 occurring stresses in round forging; 3 (0 ° rotation) and 4 (13.5 ° rotation) comparisons of the normal stress ⁇ r at the shell-core interface for flat hammers and "round hammers".
  • the stresses are plotted as a function of the arc length, an element width being chosen as the unit of length.
  • 16 is a schematic Cut; 17 shows a section perpendicular to the workpiece axis; 18 shows a section through the tools of a three-hammer forging machine; 19 shows a section through a compound round rod produced on a flat hammer forging machine; 20 and 21 sections through composite rods produced on a rotary hammer machine; 22 shows a tool with a plurality of sections with different conical working surfaces; 23 a tool with work surfaces with partially curved generatrices and FIG. 24 a section of a workpiece.
  • FIGS. 1a and 1b The geometrical relationships used for the calculations in compound forging with flat and "round hammers" are shown schematically in FIGS. 1a and 1b.
  • the four hammers are engaged at the same time.
  • the rod is advanced in the axial direction from left to right as shown in FIGS. 1a and 1b and also rotated.
  • an angle of rotation of 13.5 ° per stroke and a deformation path of the hammers per stroke of 0.447 mm were assumed in order to be able to investigate the efficiency of the new process.
  • a round composite was investigated with the cold work steel X 155 CrVMo 12 1 as the core and the case hardening steel 16 MnCr 5 as the shell.
  • the outer diameter of the casing material was 180 mm and the inner diameter was 85 mm.
  • the radius of curvature of the round hammers was assumed to be 100 mm.
  • the medium stress ⁇ m represents the hydrostatic part of the stress tensor and gives an indication of the risk of brittle fracture.
  • the higher ⁇ m in the tensile area the more likely it is that the contact surface will tear open or a metallic connection will be prevented.
  • the tangential stresses (Fig. 5, 6) are in all cases in the pressure range up to about 40 N / mm2, whereby the higher stresses occur when forging with the round hammer.
  • the medium stress characterizing the hydrostatic pressure component is at the end of the first stroke in the non-depressed part of the workpiece by about 3 N / mm2 tension (Fig. 7), while when using the "rotary hammer" compressive stresses between 10 N / mm2 and 35 N / mm2 occur continuously .
  • the risk of tearing open at the round hammer is particularly clear Contact areas.
  • the medium voltage After the second stroke, even when using the flat hammer, the medium voltage only reaches slight positive values in part of the contact area (Fig. 8).
  • the shear stresses ⁇ rt and ⁇ rz can cause shearing at the contact surfaces.
  • the stresses ⁇ rt for flat and "round hammers" are plotted over the arc length. They reach a maximum value of approx. 20 N / mm2, in which case there are no significant differences between flat and round hammers.
  • the maximum value of the shear stress ⁇ rz for the flat hammer is approx. 16 N / mm2, for the round hammer it is approx. 2 N / mm2, which is a comparatively much more favorable value.
  • a graphic representation of this shear stress has been omitted.
  • both tangential and radial tension are in the pressure range (6 to 7 N / mm2 for the flat hammer and 28 to 29 N / mm2 for the "round hammer”).
  • the medium tension ⁇ m is in the order of 10 N / mm2 when using the flat hammer Werner, while for the "Rundhammer” compressive stresses of the same order of magnitude arise.
  • the low risk of cracks in round forging with "round hammers” is also quantitatively proven.
  • FIGS. 20 and 21 round rods result in the procedure according to the invention, in which the individual layers are arranged concentrically on average despite the deformation and have a cylindrical shape along their connection.
  • FIG. 19 shows a section through a round rod produced on a flat hammer arbitration machine, in which the action of the individual blows of the flat hammers can be seen; the layers are no longer concentric with each other; the irregularities result in reduced strength and deteriorate wear behavior.
  • Fig. 15 is schematically the forging of a two layers 2, 2 'existing workpiece that produces a composite round rod 1 with four hammers 4 with conical striking surfaces 6.
  • Fig. 16 shows schematically in section the production of a composite round rod 1, in which the inner layer 2 is formed from a metal powder which is baked together and welded to the outer layer 2 ', the work piece is deformed in the hammers 4 to an outer shape corresponding to a truncated cone 5.
  • the outer layer could be formed by a metal powder located in a block capsule, which is welded to an inner core.
  • Fig. 17 shows a section through the hammers 4 of a four-hammer radial forging machine and a workpiece with three layers 2, 2 ', 2 ⁇ , the middle layer 2 ⁇ being a powder layer, e.g. can be made of Ni powder, which strengthens the connection of the other two layers 2 and 2 'or prevents carbon depletion of one of the layers or the formation of brittle phases.
  • a powder layer e.g. can be made of Ni powder, which strengthens the connection of the other two layers 2 and 2 'or prevents carbon depletion of one of the layers or the formation of brittle phases.
  • Fig. 18 shows a section through a three-hammer radial forging machine and a workpiece in which an inner powder layer 2 ⁇ is surrounded by layers 2 and 2 'of different metals.
  • the deformation is intended to detect the entire circumference of the workpiece 3 on the same side;
  • the forging tools 4 which each have a working surface 5 in the form of a partial truncated cone surface, have a truncated cone 6 that is as closed as possible in their bottom dead center position.
  • the spaces between the tools 4 in the bottom dead center position are kept as small as possible.
  • the tools 4 strike simultaneously in one plane and, in order to avoid the occurrence of burrs or to achieve a uniform forging, the workpiece is not only advanced axially with a manipulator, not shown, but also by a certain angle after each working stroke its axis ge turns.
  • FIG. 22 shows a section through tools 4 which form a number of successive truncated cone sections A, B, C.
  • the number of sections and the angle of inclination of the individual wall surfaces 5 of the tools which determines the instantaneous degree of deformation of the workpiece, is selected depending on the materials to be forged. For example, also only a section or sections with the same inclination can be provided, between which sections with different inclinations lie.
  • the tubular hammer shown in Fig. 1b also shows two truncated cone sections of different conicity.
  • the generatrices of the truncated cones are not straight lines but are curved inwards or outwards, so that the striking surfaces are curved in two mutually perpendicular directions.
  • the transitions between the truncated cone sections can be rounded.
  • Such a tool is shown in FIG. 23.
  • the area A has conical work surfaces 5, while the areas B and D bulge into the interior of the tool and the area C has a work surface 5 bulged outwards. In the bottom dead center position, the working surfaces of the tool thus form the shape of a number of bulged truncated cones.
  • Fig. 24 shows the structure of a raw material body consisting of an inner powder core 2 ⁇ , which is arranged in a tube 2, which is closed on its end face 8 after evacuation.
  • the tube 2 is surrounded by a connection aid 7, for example a thin layer Ni powder, which in turn is surrounded by a tube 2 '.
  • the tube 2 ' is surrounded by a sheet metal capsule 9, in which a further layer of powder 2 ⁇ is arranged.
  • the workpieces can be deformed by hitting or pressing on the tools.
  • the powder layers are enclosed in sheet metal capsules and applied to a core or inserted into a tube forming a layer of the primary material body. It is also possible to apply the powder directly to a core and then encapsulate it from the outside.
  • the powder is advantageously heated after an evacuation and a closure of the powder chamber or under protective gas.
  • connecting aids in the form of thin sheet metal inlays powder layers, e.g. made of Ni, from applied to a layer galvanic, plasma-deposited or the like. Layers, e.g. made of Ni, etc., which form stable metallic connections with the adjacent layers.
  • Composites with different properties can be manufactured with favorable interventions in the structure and better connection of the individual layers.
  • All types of steel and alloys, such as tool steels, are used as material for the individual layers Question;
  • the manufactured composite materials are used, for example, to produce machine parts, stamps, high-pressure pipes, tools, etc.
  • the forging temperatures in the present process are selected on the basis of the temperatures known for the alloys used.
  • the engraving was made.
  • the engraving surface produced a much higher durability and quality compared to conventionally manufactured materials.
  • a cold-forming die was made from the second part of the composite rod for the production of plow screws or gate screws. When these screws are created, high expansion stresses and signs of wear occur in the die. In practical use, this die was able to be used three times longer, which revealed the high quality of the materials and the metallic composite.
  • a conventionally produced steel rod of the alloy brand C45 according to DIN with a diameter of 300 mm was concentrically connected with a capsule made of carbon steel, which had a diameter of 380 mm.
  • the space between the capsule shell and the core was filled with high-speed steel powder of the alloy brand S 12-0-5-5 and pre-compacted by vibration. This was followed by evacuation with the action of vibration and subsequent closing of the capsule.
  • the hot-formed was carried out with rotary hammers to an outer diameter of the composite rod of 250 mm, which corresponds to a degree of deformation of 2.3 to 1. After the blank was soft-annealed, a roller mill was roughly manufactured.
  • the subsequent hardening of the blank was matched to the high-speed steel alloy of the outer part, after which the finishing was carried out by sleeping. Machining as well grinding was also much easier and more cost-effective, which revealed the corresponding quality and homogeneity of the outer material. Furthermore, there were no signs of distortion during the hardening process. In practical operation, it was found that even when these composite milling cutters were subjected to impact stresses, no cracking, which usually starts from the internal keyway, was shown. Furthermore, the service life that could be achieved was 1.9 times that of conventionally manufactured milling cutters. This is particularly noteworthy because a tool geometry was used which produces significantly higher cutting performance, but shows extremely high signs of wear in conventionally manufactured milling cutters.
  • a composite steel was produced as follows: In a pre-forged and machined tubular body made of an alloy (material number 1.7765) with an outer diameter of 170 mm and an inner diameter of 120 mm, a core made of free-cutting steel (material number 1.0737) with a Outside diameter of 80 mm introduced centrally. The space was filled with alloy powder (material number 2.4979), after which a pre-compression was carried out by pressing. The powder room was sealed airtight after the evacuation. After the blank had been heated to a temperature of 1180 ° C., it was forged with round hammers to a composite rod diameter of 100 mm, which corresponds to a deformation of 2.9 to 1.
  • a composite steel was manufactured following.
  • a tube with an inner diameter of 100 mm and an outer diameter of 200 mm was set axially symmetrically in a capsule.
  • Both the outer space between the tube of the capsule, which had a diameter of 380 mm, and the inner space of the tube were filled with alloy powder (material number 1.7220), which was precompressed with shaking.
  • the blank was heated to a temperature of 1175 ° C. within 7 hours.
  • the hot deformation was carried out on a radial forging machine using round hammers with a cone angle of 6 °.
  • the final cross-section was 280 mm, which corresponded to a deformation of 1.84 to 1.
  • the blank was machined, a 55 mm diameter hole was drilled centrally and the outer zone was provided with a spiral screw contour.
  • this machine part no distortion occurred because the binding surfaces were axially symmetrical and concentric. In practical operation, this was subjected to the highest stress Machine part an extremely high service life improvement of 11.5-fold can be achieved because on the one hand the wear resistance of the working zones was significantly increased and on the other hand the tough intermediate layer made of tempered steel absorbed the tensile and bending stresses of this hollow screw, whereby crack formation or premature breakage could be avoided.
  • Valve spindles are exposed to high torsional stress and must have adequate wear resistance and corrosion resistance, especially in the area of the valve seat.
  • Composite material was produced for the valve stem production, whereby the blank consisted of an outer tube with a diameter of 80 mm or an inner diameter of 60 mm, into which an inner cylinder was inserted with a clearance of 0.8 mm on average.
  • the outer tube was made from the alloy according to material number 1.4116, the inner part from a material according to material number 1.4006.
  • the annular space was flushed with inert gas and then the annular gap was closed to prevent the entry of oxygen.
  • the round hammer forging on the radial forging machine was carried out at a temperature of 1150 ° with a deformation of 1.78 to 1.
  • the valve spindles were of significantly higher quality, which was documented by improved break resistance and service life.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Materials Engineering (AREA)
  • Forging (AREA)
EP88890141A 1987-06-12 1988-06-10 Procédé et machine de forgeage pour la fabrication de corps composites Ceased EP0299948A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
AT1506/87 1987-06-12
AT150687A AT388318B (de) 1987-06-12 1987-06-12 Verfahren und schmiedemaschine zur herstellung von verbundkoerpern

Publications (2)

Publication Number Publication Date
EP0299948A2 true EP0299948A2 (fr) 1989-01-18
EP0299948A3 EP0299948A3 (fr) 1990-08-08

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EP88890141A Ceased EP0299948A3 (fr) 1987-06-12 1988-06-10 Procédé et machine de forgeage pour la fabrication de corps composites

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EP (1) EP0299948A3 (fr)
AT (1) AT388318B (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0392644A3 (fr) * 1989-04-12 1991-07-03 MANNESMANN Aktiengesellschaft Procédé pour enlever des bourrelets de refoulement longitudinaux
DE4434958A1 (de) * 1994-09-30 1996-04-11 Solida Werkzeugtechnik Vorrichtung zur Herstellung von Präzisionsschmiedeteilen
CN118527592A (zh) * 2024-07-25 2024-08-23 西安欧中材料科技股份有限公司 一种粉末冶金钨基高速钢的锻造方法及应用

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN119609025A (zh) * 2024-12-12 2025-03-14 哈尔滨工业大学（威海） 一种组合脉冲局部加载连续缩口成形方法

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3175387A (en) * 1962-11-14 1965-03-30 Cobelux S A High speed swaging machine
US3333452A (en) * 1965-03-03 1967-08-01 Sendzimir Inc T Reduction of thick flat articles
DE1627678B1 (de) * 1967-06-20 1971-10-28 Hatebur Ag F B Vorrichtung zum überwiegenden Kaltpressen aussen hinterschnittener, vorgepresster Zwischenoresslinge
DE2709163C3 (de) * 1977-03-03 1980-01-10 Erich 5500 Trier Ribback Verformungsmaschine zum Verformen von stangenförmigen Werkstücken
AT358365B (de) * 1978-11-29 1980-09-10 Ver Edelstahlwerke Ag Schmiedegesenk
AT372316B (de) * 1981-11-13 1983-09-26 Gfm Fertigungstechnik Schmiedemaschine
FR2528736A1 (fr) * 1982-06-21 1983-12-23 Ryazanskoe Proizv Obie Mecanisme de forgeage pour machine a forger
US4640814A (en) * 1985-10-17 1987-02-03 Crucible Materials Corporation Method for producing clad tubular product

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0392644A3 (fr) * 1989-04-12 1991-07-03 MANNESMANN Aktiengesellschaft Procédé pour enlever des bourrelets de refoulement longitudinaux
DE4434958A1 (de) * 1994-09-30 1996-04-11 Solida Werkzeugtechnik Vorrichtung zur Herstellung von Präzisionsschmiedeteilen
DE4434958C2 (de) * 1994-09-30 2001-04-12 Solida Werkzeugtechnik Verfahren und Vorrichtung zur Herstellung von Präzisionsschmiedeteilen
CN118527592A (zh) * 2024-07-25 2024-08-23 西安欧中材料科技股份有限公司 一种粉末冶金钨基高速钢的锻造方法及应用

Also Published As

Publication number Publication date
ATA150687A (de) 1988-11-15
EP0299948A3 (fr) 1990-08-08
AT388318B (de) 1989-06-12

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