JP2013517400A - Super-hard insert for boring tools - Google Patents

Abstract

  An ultra-hard insert for a rotary boring tool includes a cutter tip having a peripheral cutter edge, at least a portion of the peripheral cutter edge comprising a plurality of hard regions and a plurality of ultra-hard regions. Defined by the edges. The edges of the super-hard region are spaced apart from each other and are separated by the edges of the hard region. The hardness of each hard region is 50% at the maximum of the hardness of each super hard region.

Description

  This disclosure relates to a super-hard insert for a rotary boring tool.

  Rotating boring tools are used to drill holes in the ground in industries such as oil or gas exploration, development and construction. A plurality of ultra-rigid inserts attached to a rotating drill bit rigid rill bit body for rock drilling can be provided. In use, the head is rotated at high speed and with great force and rotationally drives the ultra-hard insert against the tip of the wall and hole to remove the rock material by a shear cutting operation. Inserts suitable for such use are also referred to as “shear cutter” inserts and may comprise a layer of polycrystalline superhard material bonded to a cemented carbide substrate. One example of a polycrystalline ultra-hard material is polycrystalline diamond (PCD).

  PCD is an ultra-hard material with inter-grown diamond grain clumps and interstices between diamond grains. PCD can be made by placing agglomerated masses of diamond grains under ultra-high pressure and ultra-high temperature. PCD is widely used to cut, drill or disassemble hard or abrasive materials such as rocks, metals, ceramics, composite materials and wood-containing materials. For example, PCD inserts are widely used in drill bits for drilling holes in the ground in the oil or gas drilling industry. In many of these areas, when the PCD material engages a rock layer, workpiece or mass, the temperature of the PCD material increases.

EP0278703 discloses a polishing body having a cemented carbide core and a cutting corner for polishing. Here, the cutting corners for polishing may be made of the same material, or may be made of different materials. The polishing body may have a layer of bonded cemented abrasive particles bonded to a substrate, and the bonded cemented abrasive particles may be diamond or cubic boron nitride.

  WO 2002/022311 discloses an insert tool comprising a tungsten carbide based cemented carbide substrate. The tungsten carbide cemented carbide base material has a plurality of pre-sintered recesses formed therein. One form of insert tool consists of a section of the substrate, with four abrasive bodies coupled to each of the four corners of the section.

  US Pat. No. 5,607,024 discloses a super-hard insert having a cutter tip attached to a support member. The cutter tip is in the form of a disk or tablet having polycrystalline diamond grains bonded together in a binder consisting primarily of cobalt. The tablet or disk is firmly attached to a cylindrical support member by a conventional high temperature and high pressure sintering process.

  US7533740 discloses a cutting element having a substrate including a tip surface and a perimeter. The tip surface extends to the periphery. A “TSP” material layer is formed on only a portion of the tip surface and extends to the periphery. In one form, the TSP is mechanically locked to the cutting element.

  Ultra-rigid inserts for rotary boring tools with reduced cost or superior properties, especially for drilling the ground or drilling or otherwise disassembling rock formations There is demand.

Means for Solving the Invention

  Here, “ultra-hard” means a Vickers hardness of at least 25 GPa.

  As a first aspect, an ultra-hard insert for a rotating boring tool, comprising a cutter tip having a peripheral cutter edge, at least a portion of the peripheral cutter edge having a plurality of hard regions and a plurality of ultra-hard Each of the hard regions is defined by a plurality of edges comprising one of the regions, the edges of the super-hard regions being spaced apart from each other and separated by the edges of the hard region A super-hard insert is provided in which the hardness is at most 50% of the hardness of each super-hard region.

  The edge of the hard region may be worn away faster than the super hard region during use to improve the cutting effect of the super hard region.

  In some forms, at least a portion of the perimeter cutter edge is angular, rounded, chamfered, or beveled.

  Here, the inclined surface is the surface of the cutting insert on which the material removed by the cutting operation of the ultra-hard insertion member flows. The removed material is typically in the form of pieces called so-called “chips”. The angle of inclination is the inclination of the inclined surface relative to the surface of the work piece or other mass that is cut and drilled or disassembled. A positive tilt angle allows the tip to move away from the workpiece, and a negative tilt angle allows the tip to move toward the workpiece.

  In some forms, the cutter tip has a plurality of inclined surfaces. The plurality of inclined surfaces may be inclined at different angles, may be arranged radially between the peripheral cutter edge and a region away from the peripheral cutter edge, and the peripheral cutter Starting from the edge, it may be referred to as a first surface, a second surface, or the like.

  In some forms, the cutter tip comprises 2, 3, 4, 5 or 10 or more edges made of ultra-hard areas.

  In some forms, the ultra-rigid insert has a generally cylindrical or disk-like form. In some forms, the ultra-rigid insert is substantially rotationally symmetric about 2, 3, 4, or 5 times around the central axis when viewed in plan view of the cutter tip. have.

  The ultra-rigid insert may be reusably attached to the tool in some forms. This helps to reduce the actual cost of the super-hard insert by extending the operating life of the super-hard insert.

  In one form, the cutter tip includes a hard central region that is separated from the peripheral cutter edge, and the cutter tip is centrally disposed between the plurality of ultra-hard regions. In one form, the central rigid region includes a raised or protruding portion. The raised or protruding portion may be formed integrally with the support, or may be fixed to the support by mechanical means, brazing means or adhesive means.

  In some forms, the raised or protruding portion advantageously functions as a chip crusher during use, in which case a chip formed from perforated or disassembled material is diverted from the cutter tip. This reduces the wear on the cut surface.

  In one form, the cutter tip includes at least one cutting surface that hangs from a raised or protruding portion toward a peripheral cutter edge.

  Negative tilt angles can be achieved without the need to modify the angle at which the ultra-hard insert is secured to the tool carrier.

  In one form, the super-hard region is on an inclined surface having a positive inclination angle. In one form, the central region has a raised portion or a protruding portion, a portion of the inclined surface depends from the raised portion or the protruding portion, and the other portion of the inclined surface forms a positive inclination angle. Adjacent to the peripheral cutter edge extending upwards, this results in a scoop-like feature at the cutter tip.

  In one form, each super-hard region has a mark to identify it.

  Two or more ultra-hard regions with different hardness or other characteristics may be readily identifiable. The user can utilize a mark to select the ultra-hard region that is most appropriate for the desired field or workpiece material (eg, rock layer type). In one form, the mark may be written in a hard region adjacent to each ultra-hard region.

  In some forms, the super-hard insert includes a plurality of spoke structures that project radially outward, each spoke having a super-hard structure.

  In some forms, each of the at least one ultra-hard region has a side that is generally converging or generally diverging when viewed in plan view of the cutter tip. Such a configuration is configured to exhibit a desired ultra-hard edge length that is substantially constant or otherwise wears in the area during use.

  The length of the edge may be substantially constant over the operating life of the ultra-rigid insert, thus extending the performance of the cutter as it is gradually worn during use.

  In some forms, the hardness of each ultra-hard region is at least about 40 GPa, at least about 50 GPa, or at least about 60 GPa. In some forms, at least one of the plurality of ultra-hard regions comprises a material having an average Young's modulus of at least 900 GPa, at least about 1050 GPa, or at least about 1100 GPa.

  In some forms, each hard region has a hardness of at least 20% or at least 30% of the hardness of each super hard region. In one form, each hard region comprises a tungsten carbide cemented carbide material.

  In one form, the super-hard insert comprises a plurality of super-hard structures with super-hard material, the super-hard structures being bonded, clamped, or otherwise joined to the support. Yes. In some forms, the support has a Young's modulus of at least about 60%, at least about 70%, or at least about 80% of the Young's modulus of each ultra-hard region.

  In general, the smaller the difference between the average Young's modulus of the support and the average Young's modulus of the superhard structure, the more robust the cutter insert and the greater the separation of the superhard structure from the support. The risk of becoming smaller is reduced, or the risk of crushing is reduced.

  In one form, the support comprises a tungsten carbide based cemented carbide.

  In one form, the support comprises a particulate or particulate ultra-hard material such as diamond or cubic boron nitride.

  The presence of the superhard material in the support can have the effect of increasing the stiffness of the superhard insert and can reduce the risk of crushing the superhard structure.

  In some forms, at least one of the superhard structures is secured to the support by pins, rivets, bolts or the like, or is clamped to the support by clamping means. In some forms, the support includes a through-hole configured to fit a fixation pin, rivet, bolt or the like. In some forms, the fixing pins, rivets, bolts or the like are threaded.

  Some forms may be particularly suitable for being fixed to the tool body by means of pins or screws. This is because they have a central region that is not super-hard and through-holes can be formed that fit into pins, rivets or screws.

  As used herein, “polycrystalline diamond” or PCD refers to a material that comprises a cluster of substantially inter-grown diamond grains and forms a skeletal structure that defines gaps between the diamond grains. .

  In one form, each ultra-hard region comprises a PCD material, preferably a thermally stable PCD. In some forms, the PCD material has a diamond content of at least about 88 volume% or at least about 90 volume%. In some forms, the PCD material has a diamond content of up to about 99% by volume.

  In some forms, at least one of the plurality of ultra-hard regions comprises subjecting the PCD or its predecessor to a pressure of at least about 7.0 GPa, or at least about 8.0 Pa, greater than about 6 GPa. PCD material obtained by.

Some forms in which the super-hard structure comprises PCD may comprise PCD sintered at a high enough pressure to cause:
Increased diamond adjacency and increased inter-grain bonding
More homogeneous spatial distribution of diamond grains Small porosity and low overall solvent / catalyst content Also, the PCD may have higher hardness, abrasion resistance and modulus or Young's modulus.

  In some forms, at least one of the plurality of ultra-hard regions comprises a PCD material comprising diamond grains having an average diamond grain adjacency of at least about 60.5% or at least about 61.5%. In general, the higher the diamond grain adjacency, the harder the crushing of the ultra-hard insert.

  In some forms, at least one of the plurality of ultra-hard regions has an interstitial mean free path of at least about 0.05 μm, at least about 0.1 μm, at least about 0.2 μm, or at least about 0.5 μm. With materials. In some forms, at least one of the plurality of ultra-hard regions comprises a PCD material having an interstitial mean free path of up to 1.5 μm, up to about 1.3 μm, or up to about 1 μm.

  High adjacency and / or high homogeneity and / or reduced metallic solvent / catalyst content in the PCD on the one hand, and at least two peaks or modes on the other hand, preferably three peaks or modes A dimensional distribution with provides a substantial improvement in wear resistance and other properties in PCD.

  In one form, at least one of the plurality of ultra-hard regions comprises a PCD material comprising diamond grains having multiple styles of size distribution. In some forms, the PCD material comprises diamond grains having an average dimension of up to about 20 μm, up to about 10 μm, up to about 7 μm, or up to about 5 μm. In one form, the PCD material comprises diamond grains having an average dimension of at least about 0.1 μm.

  In one form, the PCD comprises diamond grains having a size distribution feature in which at least 50% of the grains have an average dimension greater than 5 μm and at least 20% of the grains have an average dimension in the range of 10-15 μm. I have.

  The volume of superhard material incorporated here can be reduced or minimized. This is important. This is because ultra-hard materials tend to be expensive to manufacture and have a high tensile residual stress.

  According to a further aspect, a rotating drill bit is provided comprising the ultra-hard insert described above or described herein.

  According to another aspect, there is provided a boring tool comprising the ultra-hard insert described above or described herein. In one form, the boring tool may be a rotating drill bit for drilling holes in the rock, for example for the purpose of extracting oil or gas.

FIG. 1A is a perspective view showing one embodiment of a super-hard insert. 1B is a longitudinal sectional view taken along line AA in FIG. 1A. FIG. 2A is a perspective view showing one embodiment of a super-hard insert. 2B is a longitudinal sectional view taken along line AA in FIG. 2A. FIG. 3A is a perspective view showing one embodiment of a super-hard insert. 3B is a longitudinal sectional view taken along line AA in FIG. 3A. FIG. 4A is a perspective view showing one embodiment of a super-hard insert. 4B is a longitudinal sectional view taken along line AA in FIG. 4A. FIG. 5A is a perspective view showing one embodiment of a super-hard insert. FIG. 5B is a longitudinal sectional view taken along line AA in FIG. 5A. FIG. 6A is a perspective view showing one embodiment of a super-hard insert. 6B is a longitudinal sectional view taken along line AA in FIG. 6A. FIG. 7A is a perspective view showing one embodiment of a super-hard insert. 7B is a longitudinal sectional view taken along line AA in FIG. 7A. FIG. 8A is a perspective view showing one embodiment of a super-hard insert. 8B is a longitudinal sectional view taken along line AA in FIG. 8A. FIG. 9 is a perspective view showing one embodiment of a super-hard insert, and a partial exploded perspective view showing the form of the super-hard insert. FIG. 10 is a perspective view showing a support and clamping means for one form of ultra-hard insert. FIG. 11 is a perspective view showing a portion of one form of a rotating drill bit for boring with the form of a plurality of ultra-hard inserts.

  Non-limiting forms will be described with reference to the drawings.

  In all figures, the same reference numerals are used to refer to the same features.

  Referring to FIGS. 1A and 1B, a super-hard insert 100 for a rotating boring tool (not shown) includes a cutter tip 110 having a peripheral cutter edge 120. At least a part of the peripheral cutter edge 120 is composed of a plurality of edges 120a, 120b, 120c, 120d, 120e formed of any one of a plurality of hard regions 122a, 122b, 122c and a plurality of super-hard regions 124a, 124b, 124c, 120f. The edges of the super-hard regions 124a, 124b, 124c are spaced apart from each other and are separated by the edges of the hard regions 122a, 122b, 122c. The hardness of each hard region 122a, 122b, 122c is 50% at the maximum of the hardness of each super hard region 124a, 124b, 124c. The super hard insert 100 includes a plurality of super hard structures 130a, 130b, and 130c. The super hard structure portions 130a, 130b, and 130c are respectively attached to a plurality of concave portions formed around the support body 140 of the super hard alloy. Each superhard structure has a surface exposed at the cutter tip 110 to provide each superhard region 124a, 124b, 124c of the cutter tip. Each of the super-hard structure portions has an edge portion that forms an edge portion of the super-hard region 124a, 124b, 124c at the tip of the cutter.

  Referring to FIG. 2, one form of the ultra-hard insert 100 appears generally elliptical when viewed from above the cutter tip 110, and a pair of elliptical long axes AA along the cutter tip 110. PCD structures 130a and 130b are provided. Each PCD structure 130a, 130b represents a super-hard region 124a, 124b on the cutter tip 110.

  With reference to FIGS. 3 and 4, one form of ultra-rigid insert 100 is generally triangular with three curved corners when viewed from above the cutter tip 110, and three Each of the PCD structures 130a, 130b, and 130c is disposed at each of the curved corners.

  Referring to FIGS. 5A and 5B, one form of ultra-hard insert 100 includes spoke structures 150a, 150b, 150c that project radially from the central region 160 of the cutter tip. Each spoke has a PCD structure 130a, 130b, 130c.

  With reference to FIGS. 6A and 6B, one form of the ultra-rigid insert 100 includes a raised or protruding portion 180 on the cutter tip 110. The raised or protruding portion 180 can function as a chip crusher during use. The raised or protruding portion 180 may be formed integrally with the support 140 or may be fixed to the support 140 by mechanical means, brazing means or adhesive means (not shown). .

  Referring to FIGS. 7A and 7B, one form of the super-hard insert 100 includes a plurality of PCD structures 130a, 130b, 130c, and each PCD structure 130a, 130b, 130c is exposed to the cutter tip 110. Has a curved surface. A clamp member 182 is fixed to the working surface 110 by means 190 such as pins, rivets and bolts, and the helicopter 184 of the clamp member 182 is exposed on the exposed surfaces 124a, 124b, 124c of the PCD structures 130a, 130b, 130c. It extends above. The helicopter 184 assists in fixing the PCD structures 130a, 130b, and 130c in place. In one form, the clamp member 182 provides an inclined surface to the cutter tip 110.

  Referring to FIGS. 8A and 8B, one form of the super-hard insert 100 includes a plurality of PCD structures 130a, 130b, 130c, each of the PCD structures 130a, 130b, 130c being cut surfaces 124a, 124b, 124c. The cutting surfaces 124a, 124b, 124c are located on inclined surfaces 186a, 186b, 186c that hang from the raised or protruding central portion 180 to the peripheral cutter edge 120. In some forms, a through hole is provided to allow the ultra-rigid insert 100 to be secured to a tool carrier (not shown) such as a boring bit by means 190 such as pins, rivets or bolts. Yes. Referring to one form of FIG. 10, the inclined surfaces 186a, 186b, 186c are arranged at different angles, and the inclined surfaces 186a, 186b, 186c are angles of the PCD structure portions 130a, 130b, 130c. Or have a visible mark that can be used to identify either or both of the slopes.

  Referring to FIG. 9, one form of the super-hard insert 100 includes a support assembly 200 that further includes a cutter support structure 210 and a base 220. The cutter support structure portion 210 can be fixed to the base portion by a mechanical lock mechanism. The locking mechanism includes at least one recess 220a, 220b, 220c formed in either or both of the base portion 220 and the cutter support structure portion 210, and at least one formed in the cutter support structure portion 210 or the base portion 220. Cooperating tongs or protrusions 230.

  Referring to FIG. 10, one form of ultra-hard insert part includes a support 140 and clamping means 142. The PCD structure (not shown) may be clamped to the support 140 by the clamping means 142.

  Referring to FIG. 11, in one form of drill bit 300 for ground and rock drilling, a plurality of forms of super-hard insert 100 according to the present invention are attached to carrier body 310. The ultra-rigid insert 100 is attached to the PCD structure so as to protrude at least partially from the carrier.

  The cutter insert may be secured to the support by a variety of means including brazing, adhesive material, mechanical means (eg, coupling to the support), or the PCD may be sintered as is conventional. May be integrally bonded to the support during the process. Preferably, the PCD structures are sintered and processed before they are secured to the support. This has the advantage that the PCD material can be prepared independently of the support to which it is finally fixed, and thus has certain limitations in making the material, for example diamond Restrictions such as the choice of solvent / catalyst type and whether the PCD gap contains a filler material can be removed.

  The homogeneity or uniformity of the PCD structure can be quantified by performing a statistical evaluation using a number of photomicrographs of the abrasive pieces. The filler phase distribution can be easily distinguished from the diamond phase distribution by using electron microscopy. The distribution of the filler phase can be measured by a method similar to the method disclosed in EP0974566 (or WO2007 / 110770). This method allows a statistical evaluation of the average thickness of the binder phase along a plurality of arbitrarily drawn lines through the microstructure. This binder thickness measurement is also referred to as “mean free path” by those skilled in the art. For two materials of similar overall composition or binder content and average diamond particle size, materials with smaller average thickness tend to be more homogeneous. This is because this implies a fine scale distribution of the binder in the diamond phase. In addition, the smaller the standard deviation of this measurement, the more homogeneous the structure. A large standard deviation implies that the binder thickness varies widely across the microstructure, i.e., the structure is not uniform and contains very different types of structures.

  The images used for image analysis should be obtained by scanning electron micrographs (SEM) taken using backscattered electron signals. Optical micrographs do not give sufficient contrast. Sufficient contrast is important for adjacency measurements. This is because inter-grain boundaries are identified based on gray scale contrast.

  Adjacency can be determined from the SEM image by image analysis software. In particular, software named “analySIS Pro” (registered trademark of Olympus Soft Imaging Solutions GmbH) of Soft Imaging System may be used. This software has a “Separate Grains” filter. According to the operating manual, this filter gives satisfactory results only when the isolated structure is a closed structure. It is therefore important to fill all the holes before applying this filter. For example, the “Morph. Close” command is used. Alternatively, help can be obtained from the “Fillhole” module. In addition to this filter, “Separator” is another powerful filter that can be used for grain isolation. This separator is also applicable to color and black and white images according to the operating manual.

  To obtain a measurement of the particle size, a method known as “equivalent circle diameter” is used. Here, a circle having a size corresponding to each microscopic observation region is specified as a binder phase in the microstructure. The collected distribution of these circles is then statistically evaluated. In much the same way as for the mean free process, the greater the standard deviation in this measurement, the less homogeneous the structure.

ここで、δはダイヤモンド境界線であり、βはバインダー境界線である。 The diamond grain adjacency, k, is a measurement of diamond-diamond contact and / or bonding and is calculated according to the following formula using data obtained from image analysis of PCD abrasive pieces.

Here, δ is a diamond boundary line, and β is a binder boundary line.

  A diamond perimeter is a portion of the surface of a diamond grain that is in contact with other diamond grains. It is measured for an assumed volume as the total diamond-diamond contact area divided by the total diamond grain surface area. The binder boundary line is a portion of the surface of the diamond grain that is not in contact with other diamond grains. In fact, the adjacency measurement is performed by image analysis of the surface of the abrasive strip, and the combined length of the line through all points on all diamond-diamond interfaces in the analyzed part. Are summed, thereby determining the diamond boundary and analogically determining the binder boundary.

  Embodiments of the present invention are described in further detail by reference to the following examples. The following examples are not intended to limit the invention.

  A PCD disc was prepared. Raw diamond powder was prepared by mixing diamond grains from sources having various average dimensions in the range of about 1 μm to about 15 μm. The average particle size of the mixed mixture was about 10 μm. The mixture is formed into an agglomerated mass and is conventionally applied on a tungsten carbide based cemented carbide (WC-Co) substrate bonded with cobalt at a pressure of about 6.8 Gpa and a temperature of about 1500 ° C. Sintered by an ultra-high pressure furnace known in the art.

After sintering, the sintered composite compact was removed from the apparatus. The molded body had one layer of PCD integrally bonded to the substrate. PDC microstructure data is shown in Table 1. The diamond content of the PCD layer was about 92% by volume. Equilibrium was cobalt and a small precipitation phase, which had penetrated from the substrate into the agglomerated diamond mass during the sintering process. Diamond grains in the PCD structure had various size distributions. Image analysis was used to analyze the homogeneity of the spatial distribution of diamond grains in PCD as well as the mutual growth of diamond grains. Grain intergrowth and contact can be expressed in terms of diamond grain adjacency. The average adjacency of PCD was 62.0% (± 1.9%). The interstitial mean free path of the PCD was about 0.74 (± 0.62) μm.

  The cemented carbide substrate was removed from the composite compact by grinding, leaving an unsupported, freestanding PCD disk. The PCD disc was ground to a thickness of about 2.2 μm and then cut into three parts by electrical discharge machining (EDS). The shape of each part is almost as shown in FIG. All three PCD parts were then treated (filtered) with acid in a well known manner to remove all of the cobalt solvent / catalyst material throughout the PCD structure.

  A substrate support, approximately as shown in FIG. 3, was fabricated from a tungsten carbide based cemented carbide mass. When viewed from above, the substrate had a generally triangular shape with rounded corners. A recess was machined into the substrate at each corner, the dimensions and shape of the recess were adapted to correspond to the PCD portion, and the PCD portion was brazed to the recess.

Claims (11)

A super-hard insert for a rotary boring tool,
With a cutter tip having a peripheral cutter edge,
At least a portion of the peripheral cutter edge is defined by a plurality of edges comprising either one of a plurality of hard regions and a plurality of ultra-hard regions;
The edges of the super-hard region are spaced apart from each other and are separated by the edges of the hard region;
The super-hard insert, wherein the hardness of each hard region is 50% of the maximum hardness of each super-hard region. The cutter tip has a hard central area that is separated from the surrounding cutter edge,
The super-hard insert according to claim 1, wherein the rigid central region includes a raised or protruding portion operable to divert a piece formed from a material to be drilled or disassembled from the cutter tip.   The super-hard insert according to claim 1 or 2, wherein at least one super-hard region has a specific mark. A plurality of spoke structures projecting radially outwards,
4. The super-hard insert according to claim 1, wherein each spoke has a super-hard structure portion.   One, two or more or each of the at least one ultra-hard region has sides that are generally converging or generally diverging when viewed in plan view of the cutter tip, The super-hard insert according to any one of claims 1 to 4.   The super-hard insert according to any one of claims 1 to 5, wherein each super-hard region has a Vickers hardness of at least 40 Gpa.   The super-hard insert according to any one of the preceding claims, wherein one, two or more or each of the plurality of super-hard regions comprises a PCD material. At least one of the plurality of ultra-hard regions comprises a PCD material;
The ultra-hard insert according to any one of the preceding claims, wherein the PCD material comprises diamond grains having an average diamond grain adjacency of at least about 60.5%. At least one of the plurality of ultra-hard regions comprises a PCD material;
Super-hard insert according to any one of the preceding claims, wherein the PCD material has an interstitial mean free path of at least 0.05 µm and at most 1 µm.   A rotary drill bit comprising the super-hard insert according to any one of claims 1 to 9.   A rotary boring tool comprising the rotary drill bit according to claim 10.

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