EP0142941B1 - Konisches Gesteinsschneidwerkzeug mit metallisch gebundenen Schneideinsätzen - Google Patents
Konisches Gesteinsschneidwerkzeug mit metallisch gebundenen Schneideinsätzen Download PDFInfo
- Publication number
- EP0142941B1 EP0142941B1 EP84307183A EP84307183A EP0142941B1 EP 0142941 B1 EP0142941 B1 EP 0142941B1 EP 84307183 A EP84307183 A EP 84307183A EP 84307183 A EP84307183 A EP 84307183A EP 0142941 B1 EP0142941 B1 EP 0142941B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- core
- cutter
- alloys
- percent
- cone
- 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.)
- Expired
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Images
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
- 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
- B22F7/062—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 involving the connection or repairing of preformed parts
- B22F7/064—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 involving the connection or repairing of preformed parts using an intermediate powder layer
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/08—Roller bits
- E21B10/22—Roller bits characterised by bearing, lubrication or sealing details
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B10/00—Drill bits
- E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
- E21B10/50—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of roller type
- E21B10/52—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of roller type with chisel- or button-type inserts
-
- 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
- B22F5/00—Manufacture of workpieces or articles from metallic powder characterised by the special shape of the product
- B22F2005/001—Cutting tools, earth boring or grinding tool other than table ware
-
- 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
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
Definitions
- the present invention is directed to improvements in the construction of rock bits. More particularly, the present invention is directed to cutter cones of rock bits having metallurgically bonded cutting inserts.
- Rock bits used for drilling in subterranean formations when prospecting for oil, gas or minerals have a main body which is connected to a drill string, and a plurality, typically three, cutter cones rotatably mounted on journals.
- the journals extend at an angle from the main body of the rock bit.
- the cutter cones rotate on their respective journals. During their rotation, teeth provided in the cones come into contact with the subterranean formation, and provide the drilling action.
- the subterranean environment is often very harsh. Highly abrasive drilling mud is continuously circulated from the surface to remove debris of the drilling, and for other purposes. Furthermore, the subterranean formations are composed of rock with a wide range of compressive strength and abrasiveness.
- the prior art has provided two types of cutter cones to cope with the above-noted conditions and to perform the above-noted drilling operations.
- the first type of drilling cone is known as "milled-tooth" cone because the cone has relatively sharp cutting teeth obtained by appropriate milling of the cone body.
- Milled tooth cones generally have a short life and are used for drilling in low compressive strength (soft) subterranean formations.
- a second type of cutter cone used for drilling in higher compressive strength (harder) formations, has a plurality of very hard cermet cutting inserts which are typically comprised of tungsten carbide and are mounted in the cone to project outwardly therefrom.
- Such a rock bit having cutter cones containing tungsten carbide cutter inserts is shown, for example, in United States Patent No. 4,358,384 wherein the general mechanical structure of the rock bit is also described.
- the cutter inserts which typically have a cylindrical base, are usually mounted through an interference fit into matching openings in the cutter cone. This method, however, of mounting the cutter inserts to the cone is not entirely satisfactory because the inserts are often dislodged from the cone by excessive force, repetitive loadings or shocks which unavoidably occur during drilling.
- the internal portion of the cutter cone includes a friction bearing wherethrough the cone is mounted to the respective journal. It also includes bearing races for balls to retain the cone on the journal.
- These internal bearing surfaces of the cone must be sufficiently hard to avoid undue wear and to support the loads encountered in drilling. To accomplish this, it has been customary in the prior art to selectively carburize certain pre-machined internal surfaces of the cone.
- a cutter cone to be mounted on a journal of a rock bit comprising: a solid core including an interior opening wherethrough the cutter cone may be rotatably mounted to a journal of the rock bit, said core also including on its exterior surface a plurality of cavities; and a plurality of hard cutter inserts in the cavities in the core characterized in that the inserts fit into respective cavities with a non-interference fit and further characterized by a powder metallurgy cladding metallurgically bonded to the outer surface of the core and to the cutter inserts for retaining the cutter inserts in the core.
- a process for making a cutter cone for a rock bit of the type having at least one journal on which the cutter cone is rotatably mounted the cutter cone having a plurality of tungsten carbide cutter inserts
- the process being characterised by the steps of: placing a plurality of cutter inserts into cavities formed in the outer surface of a solid core of the cutter cone without an interference fit, depositing a powder composition on the outer surface of the core so as to partially embed the cutter inserts pressing the powder in a mould to substantially conform to the desired final exterior configuration of the cutter cone; and heating the powder to a temperature below its melting point to metallurgically bond said powder to the cone and thereby provide an exterior cladding of the cutter cone for retaining the cutter inserts in the cavities.
- a process for securing at least one cemented carbide insert to a steel core comprising the steps of: placing such a carbide insert into a cavity formed in the outer surface of a solid core of steel, the cavity being dimensioned to accept the cemented carbide insert without substantial interference; applying a powder composition on the outer surface of the steel core so as to partially embed the cemented carbide insert pressing the powder in a mould to substantially conform to a desired final exterior configuration; and heating the powder to metallurgically bond said powder to the steel core and thereby provide an exterior cladding of the steel core for retaining the carbide insert in the cavity.
- the cutter cone has a tough shock resistant core, and hard, cutting inserts fitted in cavities provided in the core.
- a hard cladding is disposed on the outer surface of the cone, having been metallurgically bonded thereto in a suitable mould by a powder metallurgy process.
- metallurgical bonding of the cladding occurs through hot isostatic pressing.
- the cutting inserts are also metallurgically bonded to the core and to the cladding as a result of the formation of the cladding through hot isostatic pressing or like powder metallurgy processes.
- the interior of the cone incorporates conventionally machined bearing surfaces and races for attachent of the cutter cone to a respective journal of the rock bit.
- the bearing surfaces and bearing races are formed in the interior of the cone from a metal powder or cermet in the same or similar powder metallurgical bonding process wherein the exterior cladding is bonded and hardened.
- the bearing surfaces are formed in a separate piece which is subsequently affixed into a bearing cavity provided in the core.
- a thin coating of a suitable material is deposited on the inserts prior to placement of the inserts into corresponding cavities in the core.
- suitable materials are copper, copper alloys, silver, silver alloys, cobalt, cobalt alloys, tantalum, tantalum alloys, gold, gold alloys, palladium, palladium alloys, platinum, platinum alloys, and nickel or nickel alloys.
- Another alternative to prevent degradation of the cutting inserts is to provide an alternate source of carbon such as a graphite layer, in the vicinity of the cutting inserts.
- Figure 1 shows a rock bit 8 wherein a cutter cone of the present invention is mounted.
- the cross-sectional view of Figure 2 shows mounting of a first embodiment of the cutter cone 10 of the present invention to a journal leg or journal 12 of the rock bit 8.
- a plurality of tungsten carbide cobalt (cermet) cutter inserts 26 are interference fitted into corresponding circular holes which are drilled individually in the cutter cone 10. This procedure is not only labour intensive, but provides a cutter cone which may have, under severe drilling conditions, less than adequate retention of the cutter inserts 26.
- the core 28 comprises tough, shock resistant steel, such as mild steel, for example AISI 9315 steel, or AISI 4815 steel.
- the core 28 itself, may be made by powder metallurgy techniques.
- a plurality of cavities 30 are provided in the outer surface 32 of the core 28 to receive, preferably by a sliding fit, a plurality of cutter inserts 26.
- the cavities 30 may be configured as circular apertures, shown in Figure 3, but may also comprise circumferential grooves (not shown) on the exterior surface 32 of the core 28.
- the cutter inserts 26 may be of other than cylindrical configuration. They may be tapered, as is shown in Figure 5, or may have an annulus (not shown) comprising a protrusion. Alternatively, the inserts may be tapered and oval in cross- section. What is important in this regard is that the cutter inserts 26 are positioned into the cavities 30 without force fitting, or without the need for precision fitting each individual insert 26 into a precisely matching hole, thereby eliminating significant labour and cost.
- the cutter inserts 26 are typically made of hard cermet material.
- the cutter inserts comprise tungsten-carbide cobalt cermet.
- other cermets which have the required hardness and mechanical properties, may be used.
- Such alternative cermets are tungsten-carbide in iron, iron-nickel, and tungsten-carbide in iron-nickel cobalt.
- tungsten-carbide-iron based metal cermets often match better the thermal expansion coefficient of the underlying steel core 28, than tungsten-carbide-cobalt cermets.
- a powdered metal or cermet composition is applied to the exterior surface 32 of the core 28, to eventually become a hard exterior cladding of the cutter cone 10.
- the metal or cermet composition is schematically shown in Figure 3 as a layer of cladding bearing the reference numeral 34.
- one function of the cladding is to retain the insert 26 in the core 28.
- the metal or cermet composition comprising the cladding should satisfy the following requirements. It should be capable of being hardened and metallurgically bonded to the underlying core 28 to provide a substantially one hundred per cent dense cladding of a hardness of at least 50 Rockwell C units. Many tool steel, and cermet compositions satisfy these requirements. For example, commercially available, well known, AISI D2, M2, M42, and S2 tool and high strength steels are suitable for the cladding.
- An excellent cladding for the present invention is the tool steel composition which comprises 2.45 weight percent carbon, 0.5 percent manganese, 0.9 percent silicon, 5.25 percent chromium, 9.0 percent vanadium, 1.3 percent molybdenum, 0.07 percent sulphur, with the remainder of the composition being iron.
- This composition is well known in the metallurgical arts under the CPM 10V designation of the Crucible Metals Division of Colt Industries.
- Still another excellent cladding material is a proprietary alloy of the above-noted Crucible Metals Division, known under the developing number 516,892.
- powdered cermets as tungsten carbide cobalt (WC-Co), titanium-carbide-nickel-molybdenum, (TiC-Ni-Mo) or titanium-carbide-iron alloys (Ferro-TiC alloys) may also be used for the cladding 34.
- WC-Co tungsten carbide cobalt
- TiC-Ni-Mo titanium-carbide-nickel-molybdenum
- Fero-TiC alloys titanium-carbide-iron alloys
- powdered material of the cladding 34 and metallurgical bonding to the underlying core 28 and its subsequent hardening are performed in accordance with well known powder metallurgy processes and conventional heat treatment practices. Although these well known processes need not be disclosed here in detail, it is noted that the powder metallurgy processes suitable for use include the use of a mould (not shown) which determines the exterior configuration of the cutter cone 10.
- the powder metallurgy process involves application of high pressure to compact the powder, and a step of heating the powdered cladding in the mould (not shown) at a high temperature, but below the melting temperature of the powder, to transform the powder into dense metal, or cermet, and to metallurgically bond the same to the underlying core 28.
- the cladding 34 incorporated in the cutter cone 10 may be obtained by cold pressing or cold isostatic pressing the powdered layer 34 on the core 28, followed by a step of sintering.
- a preferred process for obtaining the hard cladding 34 for the cutter cone 10 is, however, hot isostatic pressing (HIPping). Details of this process, including the preparatory steps to the actual hot pressing of the cutter cone 10, are described in United States Patent Nos. 3,700,435 and 3,804,575, the specifications of which are hereby expressly incorporated by reference.
- the hot isostatic pressing step is preferably performed between approximately 1900 to 2200°F (1038°C to 1204°C), for approximately 4 to 8 hours, at approximately 15000 to 30000 PSI (2x106 to 2x10 6 Pa).
- certain further heat treatment steps are performed on the cutter cone 10.
- the conditions for quenching and tempering are preferably those recommended by the suppliers of the powdered steel composition which is used for the cladding 34.
- the cutter cone 10 obtained in the above-described manner has an exterior configuration which corresonds to the final, desired configuration of the cutter cone 10 usable in a rock bit. In other words, little, if any, machining is required on the exterior of the cutter cone 10. Thickness of the cladding is not critical; the cladding may, for example, be 1/8 inch (3.2 mm) thick.
- a further, very significant advantage is that the cutter inserts 26 are affixed to the core 28 and to the cladding 34 by metallurgical bonds.
- a tungsten carbide cobalt insert (of the size normally used for rock bits, having 0.5" (12.7 mm) in diameter and a 0.310" (7.9 mm) "grip) affixed to the cutter cone 10 as described herein requires on the average a pulling force in excess of 21000 Ibs (9534 Kg) to dislodge the insert from the cone 10.
- conventional, interference fitted inserts are dislodged from the cone 10 by a force of approximately 7000 to 10000 Ibs (3178 to 4540 Kgs).
- the cladding 34 of the cone 10 is substantially one hundred per cent (99.995%) dense, and has a surface hardness of at least 50 Rockwell C Units.
- the interior of the solid intermediate cutter cone 10 shown in Figure 3 may be machined independently of the hot isostatic pressing process, to provide the cutter cone interior shown in Figure 1.
- the core 28 itself may be formed by powder metallurgy in steps separate from the above-described steps.
- conventional, bearing surfaces for example, aluminium-bronze, or hard metal bearings, for example, cobalt based hard facing alloys may be applied into the interior of the cone 10 in accordance with the state of the art.
- bearing surfaces may be formed separately from the fabrication of the core 28.
- a separate bearing insert piece (not shown) is fitted into the hollow core.
- FIG. 4 a second embodiment of the cutter cone 36 is shown.
- This embodiment has interior bearing surfaces 38 and races 40 obtained by a powder metallurgy process, preferably a processing including a hot isostatic pressing step.
- a forged mild steel core is provided by a machined interior cavity, or opening 42, and a plurality of exterior cavities or apertures 30.
- the exterior apertures 30 receive cutter inserts 26 in a sliding fit, as it was described in connection with the first embodiment.
- the exterior cladding 34 is applied to the core 10 in the manner described in connection with the first embodiment.
- a powdered metal or cermet composition is also bonded in the interior cavity 42 through a powder metallurgy process, to provide the bearing races 40 and bearing surfaces 38.
- the interior surfaces of the cutter cone 36 emerge from the hot isostatic pressing process in a "near-net" shape, and therefore do not require extensive finish machining.
- the tungsten carbide cobalt cutter inserts 26 have a thin coating or layer 44 of a material which prevents diffusion of carbon from the tungsten carbide into the underlying steel core 28 during the high temperature hot isostatic pressing or sintering process. As is known, such diffusion has a significant driving force because the carbon content of the steel core 28 typically is low. Loss of carbon from the tungsten carbide results in formation of "eta" phase of the tungsten carbide, which has significantly less desirable mechanical properties than the original tungsten carbide insert.
- a layer of graphite also prevents degradation because it provides an alternate source of carbon.
- a layer of graphite is readily placed on or near the insert 26 for example, by applying a suspension of graphite in a volatile solvent, such as ethanol, on the insert 26.
- the graphite prevents or reduces diffusion of carbon from the tungsten carbide because it eliminates the driving force of the diffusion.
- the metal coatings may be applied to the cutter inserts 26 by several methods, such as electroplating, electroless plating, chemical vapour deposition, plasma deposition and hot dipping.
- the metal layer or coating 44 on the cutter inserts is preferably approximately 25 to 100 microns (0.001 to 0.004") thick.
- the metal layer 44 deposited on the cutter insert preferably should not melt during the hot isostatic pressing or sintering process. It certainly must not boil during said processes. Nickel or nickel alloys are most preferred materials for the coating or layer 44 used in the present invention.
- the metal coating 44 on the inserts 26 not only prevents the undesirable "eta" phase formation in the insert 26, but also provides a transition layer of intermediate thermal expansion coefficient between the tungsten carbide inserts 26 and the surrounding ferrous metal cladding 34 and core 28. In the absence of such a transition layer the boundary cracks readily. Nevertheless, as it was noted above, test results in the absence of such a metal coating still show significant improvement over non-metallurgically bonded inserts with regards to the force required to dislodge the inserts 26.
- Figure 6 schematically illustrates a Scanning Electron Microscope (SEM) micrograph of the boundary layers between the tungsten carbide cutter insert 26 and a nickel layer 44 on the one hand, and the nickel layer 44 and the underlying core 28, on the other hand.
- SEM Scanning Electron Microscope
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Mechanical Engineering (AREA)
- Fluid Mechanics (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Materials Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Composite Materials (AREA)
- Earth Drilling (AREA)
Claims (27)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US54492383A | 1983-10-24 | 1983-10-24 | |
| US544923 | 1983-10-24 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0142941A1 EP0142941A1 (de) | 1985-05-29 |
| EP0142941B1 true EP0142941B1 (de) | 1989-06-07 |
Family
ID=24174141
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP84307183A Expired EP0142941B1 (de) | 1983-10-24 | 1984-10-18 | Konisches Gesteinsschneidwerkzeug mit metallisch gebundenen Schneideinsätzen |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0142941B1 (de) |
| CA (1) | CA1231938A (de) |
| DE (1) | DE3478627D1 (de) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4597456A (en) * | 1984-07-23 | 1986-07-01 | Cdp, Ltd. | Conical cutters for drill bits, and processes to produce same |
| US4562892A (en) * | 1984-07-23 | 1986-01-07 | Cdp, Ltd. | Rolling cutters for drill bits |
| US4708752A (en) * | 1986-03-24 | 1987-11-24 | Smith International, Inc. | Process for laser hardening drilling bit cones having hard cutter inserts placed therein |
| US5038640A (en) * | 1990-02-08 | 1991-08-13 | Hughes Tool Company | Titanium carbide modified hardfacing for use on bearing surfaces of earth boring bits |
| CN101144370B (zh) * | 2007-10-24 | 2010-12-08 | 中国地质大学(武汉) | 热压高磷铁基金刚石钻头的制备方法 |
| CN103042208B (zh) * | 2013-01-22 | 2015-06-10 | 广东新劲刚新材料科技股份有限公司 | 铁和碳化钛混合料及其在冷压模具表面制作涂层的方法 |
| EP2821166B1 (de) * | 2013-07-04 | 2016-04-20 | Sandvik Intellectual Property AB | Verfahren zur Herstellung einer verschleißbeständigen Komponente mit mechanisch gekoppelten zementierten Karbidkörpern |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB449974A (en) * | 1935-04-29 | 1936-07-08 | John Corstorphine | An improved boring and drilling tool |
| US2999309A (en) * | 1955-04-06 | 1961-09-12 | Welded Carbide Tool Company In | Composite metal article and method of producing |
| US3444613A (en) * | 1965-11-24 | 1969-05-20 | Coast Metals Inc | Method of joining carbide to steel |
| US4172395A (en) * | 1978-08-07 | 1979-10-30 | Dresser Industries, Inc. | Method of manufacturing a rotary rock bit |
| DE3030010C2 (de) * | 1980-08-08 | 1982-09-16 | Christensen, Inc., 84115 Salt Lake City, Utah | Drehbohrmeißel für Tiefbohrungen |
| SE423562B (sv) * | 1980-11-13 | 1982-05-10 | Cerac Inst Sa | Forfarande for framstellning av en stalkropp innefattande insatser av hart material |
| US4365679A (en) * | 1980-12-02 | 1982-12-28 | Skf Engineering And Research Centre, B.V. | Drill bit |
-
1984
- 1984-10-18 EP EP84307183A patent/EP0142941B1/de not_active Expired
- 1984-10-18 DE DE8484307183T patent/DE3478627D1/de not_active Expired
- 1984-10-23 CA CA000466146A patent/CA1231938A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE3478627D1 (en) | 1989-07-13 |
| CA1231938A (en) | 1988-01-26 |
| EP0142941A1 (de) | 1985-05-29 |
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