TW200944596A - Methods of thermo-mechanically processing tool steel and tools made from thermo-mechanically processed tool steels - Google Patents

Abstract

A method of thermo-mechanically processing a preform (65) composed of tool steel and a tool (18) to modify a workpiece (28). The preform (65) has a region (70) containing austenite. The method comprises establishing the region (70) at a process temperature between a martensitic start temperature and a stable austenitic temperature. While at the process temperature, the region (70) is deformed to change an outer dimension and to modify the microstructure to a depth of 1 millimeter or more. The tool (18) comprises a member (20) composed of tool steel. The member (20) includes a first region (30) that extends from the outer surface (22) to a depth of greater than 1 millimeter and a second region (32). The first region (30) includes a plurality of grains having an average misorientation angle greater than about 34 DEG, an average grain size that is at least 10% smaller than the second region (30), and has a different grain orientation than the second region (30).

Description

200944596 VI. Description of the Invention: [Technical Field of the Invention] The present invention relates to thermomechanical processing of tool steel, a method of forming a tool using thermo-machined tool steel, and a tool for metal forming and metal cutting applications. This application is a part of the serial case of the application in the middle of the same year on March 13th. The case claims the rights of the US Provisional Application (4) No. 60/896,729. The disclosure of each of the disclosures is hereby incorporated by reference in its entirety. This application also claims the benefit of U.S. Provisional Application No. 6i/Q29,236, filed on Feb. 15, 2008, which is hereby incorporated by reference in its entirety. [Prior Art] Among various grades of commercially available carbon and alloy steels, tool steel grades are commonly used in applications where the tool is subjected to hazardous stress, shock and/or wear. Tool steels are often characterized by superior hardness, wear resistance, ability to maintain cutting edges, and resistance to deformation at elevated temperatures. As a result, tool steels are widely used in metal forming and metal cutting applications, inspection equipment and gauges, and wear/impact components in machine tools. Various types of tools are used in metal forming and metal cutting applications such as machining, perforation, die-cutting, drawing, powder pressing, metal engraving, pinning, and the like. In particular, the punches and dies represent metal forming tools of the type used to pierce, punch, and shape metal and non-metal workpieces. Shear 4 tools and inserts represent metal cutting tools of the type used for machining applications to shape metal and non-metal workpieces. Plug gauges, thread gauges, tubes 138621.doc 200944596 gauges, ring gauges and school plates represent tools used to verify the type of application. Machine Finding Slides and Inserts represent wear and impact components of the type used in machine tools. Punches and dies are subjected to severe and repeated loads during their lifetime. In particular, the punch is susceptible to damage during use due to severe breakage caused by significant stress experienced during its use. With steels with higher strength to weight ratio (such as ultra high strength steel (UHSS), advanced high strength steel (AHSS), phase change induced plastic (Dip Rip) steel, twin induced plasticity (TWIP) steel, nano The introduction of workpieces constructed of steel and martensite (MART) steel has become more demanding on metal forming tools. For example, the automotive industry is increasingly using these types of high-strength, low-weight steels for body structure transformations. Therefore, there is a need for a method for thermomechanical processing of steel and its mechanical properties, and a tool formed by thermomechanical processing having improved mechanical properties. SUMMARY OF THE INVENTION μ φ In an embodiment, a method of thermomechanically processing a preform comprising tool steel is provided. The tool steel has a martensite start temperature and a stable Worth field μ degree. The preform has a region containing a Worth field that includes a surface and a plurality of outer dimensions for the outer surface. (d) The method comprises establishing at least the pre-formed region at a processing temperature between the martensite start temperature and the stable Worth field temperature. When the region of the preformed field is at the processing temperature, the region is deformed to change at least one of the outer dimensions of the region and the microstructure of the region is modified from a depth extending from the outer surface One depth for the outer surface of 1 mm or more than 1 mm 13862I.doc 200944596. After the area was deformed, the area was cooled to room temperature. In another embodiment, a tool for use in a machine to modify a workpiece is provided. »The 衾 tool contains a component that contains tool steel. The member has an outer surface that defines a first portion that is configured to couple with the machine and a second portion that is adapted to contact the workpiece. The member includes a first region extending from the outer surface to a depth greater than 丨m and a second region separated from the outer surface by the first region. The first region includes a plurality of crystal grains having a misaligned angular distribution having a greater than about 34. The average misorientation angle; an average grain size that is at least 10% smaller than the second region; and has a grain orientation that is different from the grain orientation of the plurality of grains in the first region. The embodiments of the present invention are described in conjunction with the accompanying drawings, in which The principle of the example. In accordance with an embodiment of the present invention, a method of making a tool includes fabricating a preform from tool steel, wherein at least a region of the preform is thermo-machined. The area of the preform typically includes a majority of the volume of the tool steel or the body portion of the preform. For example, for a cylindrical preformed field geometry, a thermomechanically machined region machined by a radial forging or plane strain forging process can balance 60% of the outer volume with the remainder of the tool steel's relative atypical processing effect. The inner volume is merged. Thus, the volume of the region of the simple pre-formed geometry can include at least the volume outside the cross-section of the preform. The region may extend at least partially across or completely across the cross-sectional area. Thus, in this embodiment, the outer volume or modified region extends from the outer surface of the region 138621.doc -6 - 200944596 to a depth greater than at least 0 039 吋 (1 mm), although the size of the volume may allow the depth to be deeper Extending into the preform _. However, the depth of the area does not have to be uniform, and the depth in one part of the area may be less than 0.039 吋 (1 mm) but the depth in the other part may extend to more than 0.039 忖 (1 nim). Although the modified region is described above as an outer volume in the form of a layer surrounding the inner volume, the modified region may be an irregular shaped region. For example, this may be a condition in which the outer surface of the preform has a geometry prior to deformation, but is deformed by at least the outer dimensions of the region to form articles having different shapes. For example, the deformation can include a change in one or more of a cross-sectional area or another-outer dimension that can increase or decrease the length of the area. Those skilled in the art will appreciate that the volume of material being processed can be determined by a number of other factors including, but not limited to, the size and shape of the preform and the ability and type of the deforming device. Generally, as the load capacity of the forging equipment increases and the size of the preformed chain decreases, the deformed area may have a larger (if not all) portion of the preform. Thus, unlike surface treatment operations, such as bead blasting and the like, embodiments of the present invention are not limited to forming a thin surface layer that is forced to conform to previously established contours. Moreover, embodiments of the present invention deform a majority of the tool steel 'and in some embodiments' to determine the preformed outer or outer surface dimensions. In this aspect, the area of the preform can be measured across the thickness of the body of the preform or tool, and the shape of the preform can be independent of the final shape of the tool, 'except for the volume of the tool steel being machined. Pre-138621.doc 200944596 before thermomechanical processing The geometry or shape of the shaped column can affect the final microstructure. For example, the shape can influence or determine the orientation of the grains and the characteristics of the thermomechanical microstructure. Those skilled in the art will appreciate that tool steel preforming can be a plurality of groups having many cross-sectional shapes. In the state, such as a bar with a circular, rectangular or polygonal cross section, or a material with a more complex shape and cross section. The determination of the pre-formed (four) shape can be based on historical experience, tool requirements, and/or processing constraints. For example, the geometry of the preform can be selected based on the processing class β Τ θ Λ α α and the target of the tool, the final geometry. The region undergoes deformation although the temperature of the region remains in the temperature range as described below in accordance with various embodiments of the present invention. In the embodiment of the invention, the amount of deformation is sufficient to improve the mechanical properties of the deformed region. The amount of deformation can be quantified by the reduction ratio calculation, and the reduction ratio is defined as the relative reduction of the cross-sectional area (4) thermomechanical processing. It is considered that the improvement of the nature of the area is proportional to the amount of deformation. An example and non-limiting 'only 2% reduction ratio can result in a measurable improvement in the mechanical properties of the zone. The improved amount of deformation that can be measured in the mechanical properties of the salt is limited only by the dynamic recrystallization of the tool steel. In other words, the amount of deformation can be kept below the threshold that effectively causes the microstructure to recrystallize dynamically. If the deformed microstructure is recrystallized, a measurable decrease in mechanical properties compared to the unrecrystallized microstructure can be observed. The reduction in specific mechanical properties can be at least about 2%. However, mechanical properties can be improved as compared to tools prepared by heat treating tool steel at temperatures above the specified temperature range, even though a decrease can be observed, as will be described in more detail below. Those skilled in the art will appreciate that in addition to the amount of deformation, 138621.doc 200944596 dynamic recrystallization depends on the composition of the tool steel and the temperature at which the deformation occurs. As explained above, thermomechanical processing involves plastically deforming tool steel preforms while the tool steel preforms are maintained at elevated temperatures. Suitable processing for plastically deformable preforms may include, but is not limited to, forging processing, such as radial forging, ring rolling, rotary forging, swaging, thixoforming, Voss forming, although other suitable deformation processes may be used. (ausforming) and warm/hot forging. For example, the technique may also include techniques in which the primary direction of deformation is not substantially perpendicular to the longitudinal axis of the preform. As discussed above, other techniques, such as bead blasting at high temperatures, produce very weak deformation and are therefore eliminated because of the need for deeper plastic deformation to provide the necessary improvements in mechanical properties. One such process is planar strain forging, which primarily produces radial and circumferential plastic deformation of the tool steel preform. Therefore, planar strain forging can limit the elongation of the grains perpendicular to the direction of the applied load. As a result, preforming can exhibit a substantially uniform distribution of mechanical properties along its length and around its perimeter. Thus, in one embodiment, planar strain forging includes plastic deformation processing that produces very little, if any, grain elongation in a particular direction. However, when thermoforming a tool steel preform, any combination of the above-described processes capable of plastically deforming the preform can be used. In another embodiment, an existing tool can act as a preform. For example, in addition to unused tools, existing tools may include tools used, damaged tools, or damaged tools. Existing tools are thermomechanically processed as described herein to remanufacture or rework the tool to restore its utility. As provided above, thermomechanical processing includes maintaining the zone 138621.doc 200944596 in the region of the preform to plastically deform the region at the processing temperature. The temperature of the preformed chain can be established by deforming the preform from a higher temperature. This process may include (by way of example only) casting a blank or preform of tool steel from the molten raw material, cooling the cast preform to a lower processing temperature and deforming it at the processing temperature. Alternatively, the preform can be brought to a processing temperature (deformed at the processing temperature) by heating the preform from room temperature or near room temperature, as described in more detail below. Detailed description 'and referring to Figure 1, the preformed chain is above the martensitic transformation (Ms) of the tool steel (the martensite start temperature) but lower than the stabilized Worth field temperature (AG) of the tool steel (When the preform contains a Worth field): Deformation at temperature. MS is the pulse of the transition from Worth to Martensite during cooling and AC3 is the temperature at which the transition from ferrite to Worth is completed during heating. In addition, as shown in Figure 1, Worthfield The body onset temperature (ACi) represents the temperature at which the Worth field begins to form during heating. Those skilled in the art will understand that the 'Ms, AC丨 and AC3 systems are each dependent on the specific component of the tool steel. Therefore, any of the examples in which Ms, AC丨 or AC3, as described in conjunction with the specific temperature, are not intended to limit the definition of Ms, ACi or AC3 to a specific temperature. Multiplying the temperature defined above and the root [item embodiment, when the tool steel preform is described at a temperature between MAAC3 and when the region contains a Worth field (eg 'Asian Worth Field') All or part of the forming process is processed 'i.e.' the tool steel preformed blister is plastically deformed or forged. Therefore, the deformed region of the tool steel preformed chain has some of the improved mechanical properties of 13862J.doc •10· 200944596 as described below. For example, when the microstructure is primarily a stable Worth field, the improvement in impact strength or toughness of the deformed region can be at least about as compared to deforming the preform at a temperature higher than ac3, and in another example Medium, can be at least 50% larger. As described above, in the embodiment, the method includes heating the worker steel preform to a temperature range such that at least a portion of the preform contains the 胄沃斯田体. Those skilled in the art will appreciate that many different degrees of profile can be utilized to bring the tool steel preform into the temperature range of the above-described limb prior to deformation. Just by example, and see the picture! The tool steel preform can be heated from a temperature below Ms to a processing temperature above ACi (mark 10). In this example, the temperature is about 1530 Torr (about 832 it) and AC3 is about 2250 F (about 1232 c). The tool steel preform can then be deformed while maintaining it at a processing temperature between AC丨 and AC3. The other-temperature profile may include heating the preform steel chain from a temperature below & to a temperature between eight and eight (: 3, and then deforming the tool steel before deforming it) The billet is cooled to a processing temperature above the MS (mark u). In another embodiment, shown in Figure 1A, the temperature profile can include heating the tool steel preform to a temperature above AC3 and then working before deforming it. • The steel preform is cooled to a processing temperature between 8 and 8. (marked 12) or • cooled to a processing temperature between Ms and 八 (^13). During the deformation, the processing temperature can be increased. Decrease or remain substantially the same, although the temperature of the zone remains between AC3 and Ms. The temperatures at which the deformation occurs (eg, 1〇, u, 丨2, and 丨3) are depicted as Horizontal line. Although the horizontal line can represent isothermal conditions, those skilled in the art will learn 138621.doc • 11 - 200944596 to understand the actual processing temperature during some of the period, tool steel preforming: the real m, in the deformation ± 5 yesterday (± 28 〇. Control temperature ^ processing - degree can be changed The closed-circuit temperature feedback is held in a substantially isothermal condition and the feed is intentionally heated or dissipated. Drop: two:, or the decrease can occur during deformation. The temperature rises or 2! can be intentional or deformed The result of the temperature is not controlled during the period. For example, in some embodiments, 'the temperature of the pre-form can be increased to mF (8rc) due to the addition of energy to the pre-form by deformation. It is heat, and if it is not compensated by heat removal or heat dissipation, the temperature of the area is raised. Therefore, the processing temperature can be raised or lowered so that the temperature of the domain starts at a temperature higher than ACi but lower than Μ. The temperature ends or ends at a temperature below the ACl and ends at a temperature above Μ. In other embodiments, the region may be intentionally cooled to reduce the temperature of the region when deformation occurs. However, it should be noted that If the pre-formed chain temperature changes significantly during the deformation process, dynamic recrystallization of the grains can reduce the impact strength and strength of the region. Therefore, the isothermal process (ie, maintaining the actual processing of the tool steel preform during deformation) The temperature is generally normal The number) can maximize the strength, toughness and other mechanical properties of the zone, as described below. The field continues with reference to Figures 1 and 1A, although various heating and cooling processes can be utilized, but the processing temperature and processing time are controlled to avoid carbide noses. End 14 or bainite nose 16. It will be understood by those skilled in the art that at temperatures below ACi, if the zone remains too long at temperatures in this range, the tool steel can be slab carbide or Bayesian. By way of example, M2 AISI tool steel preforming can be as long as 138621 .doc -12· 200944596 in the absence of significant carbide "bainite phase formation" in at least 2 minutes & internal deformation U 'preform The amount of time that & can remain at this temperature depends at least on the composition and temperature of the tool steel, as well as other factors. After thermomechanical processing, the preform is cooled to a lower temperature. Cooling or quenching can be achieved by forced air convection or by maintaining the zone at a moderate temperature before cooling the preform to room temperature. Those skilled in the art will understand that quenching

The fire may include other cooling methods or media, including, for example, water or oil bonfires. By way of an additional example, the zone can be subjected to a low temperature process in which the zone is cooled in one or more (four) segments to a temperature between about 15 (TF (about -101 〇 c) and about -30 yesterday (about _). A large percentage of the residual Worth field is converted to martensite. Low temperature treatment can be achieved by, for example, liquid nitrogen, and this treatment can be used primarily in combination with D2 tool steel, although it contains a significant percentage of residual Worth field Other tool steels can benefit from this type of treatment. The quenching rate is greater than the critical cooling rate of the tool steel', ie to prevent non-ideal transformations (such as, carbide nose! 4 and bainite nose 16) The minimum rate of continuous cooling. Therefore, the 'cooling rate is sufficient (4) to significantly convert from the Assyrian to non-ideal decomposition products (such as carbide or bainite). Faster cooling rates can also be utilized, although faster cooling rates are limited to Such as not to thermally impact the area or otherwise twist the tool steel preform. Further, in the embodiment, there is __ or multiple tempering after cooling, and σ tempering may include heating the area To approximately 85〇卞 ( 4541 ) and The temperature between Miyazaki (about 537. 〇) lasts from about μ to about 6 gongs. The tempering is changed by converting the residual Worth field to martensite. I38621.doc J3- 200944596 Microstructures. Such a technique is known, and multiple tempering cycles can be used to convert the residual Worth field. Those skilled in the art will understand that the shape and size of the tool steel can be preformed and allowed. Depending on the amount of Meredithian volume and the number of tempering treatments used, tempering may include heating to a higher or lower temperature for a shorter or longer period of time. According to one embodiment, after quenching, back The zone before the fire is not heat treated at a temperature of AG or higher than A. Furthermore, the zone may not be heated above any temperature experienced by the zone during deformation. In other words, the preform may be reheated, however, any subsequent The temperature during heating does not significantly reduce or modify the strain or differential row established by the Worth field in the deformation zone at a temperature between the stable Worth field temperature and the martensite start temperature. In the embodiment, the method One step includes trimming the tool steel preform into a tool after the thermomechanical deformation process. The trimming may include material removal (4) resulting in a final shape and/or surface "surface. For example, the S' conventional trimming process may include Machining, grinding, sanding/polishing, or a combination thereof to prepare a tool for use. However, trimming may require removing only a small amount of material to form the preform into a tool. For example, the deformation may include near net shape The forging process requires (after deformation) a small subsequent processing (if present) of the pre-formed (d) to produce the tool. - or multiple secondary processes may follow the cooling or trimming of the implement. The secondary process includes a certain way Forming a coating on the tool or further modifying the surface of the tool. An exemplary secondary process includes thermal spraying or covering the deformed area of the tool or the entire tool with an anti-wear material. Other secondary processes include coating the working surface of the tool by coating techniques including 138621.doc •14·200944596 (but not limited to) physical vapor deposition (PVD), chemical vapor deposition (CVD) or salt bath coating. Other surface modification techniques include ion implantation, laser or plasma hardening techniques, nitridation or carbonization, which can be used to modify the surface layer at the working surface of the tool. It should be appreciated that any of a variety of secondary processes can be used in any combination to further modify the tool. As explained above, the preform comprises tool steel. Tool steel represents a type of steel from which tools for cutting, forming or otherwise forming another material are made. The tool steel can be hardened by heat treatment and can be tempered to achieve the desired mechanical properties. For example, preforms can be made from a variety of different types of tool steels, such as cold work, hot work, high speed tool steel grade materials, or exclusive tool steel grades. In particular, the tool steel is an iron-1⁄4 (Fe-C) alloy system having a carbon content ranging from about 35% by weight to about 1% by weight, and in another example, by the desired carbonization. The expected other carbon content, if any, is from about 85% by weight to about 1.30 by weight. Within the range of /0. The φ tool steel usually contains an additive of a carbide forming element such as vanadium (V), tungsten (W), chromium (Cr), molybdenum (Mo) or a combination thereof. Depending on the alloy addition, one or more carbide phases (e.g., M6c, m2c, m23c6, M7Cpt-M4C) may precipitate, although other types of carbides are known to be formed in the art. With few exceptions, the tool steel does not contain the intentional additive nickel (Ni) 0 nickel as the known Vostian bulk stabilizer. However, tool steels may contain trace amounts (up to 0.3 weight 〇/〇) for this element. Table 1 shows the nominal composition of the weight percent of the exemplary steep tool steel that can be used to make the tool according to an embodiment of the present invention (the rest of the tool steel 138621.doe •15·200944596 is divided into iron (Fe)). By way of example, Table 1 _ tool steel ac3 is located between about 2100 °F (about 1149t) and about 2400T (about 1316. 〇, ACi temperature is about 1380T (about 749 ° C) and about 1680T (about Within the range between 915.6 〇C), and Ms is in the range between about 320 T (about 160 〇 and about 480 T (about 249 ° C). Table 1

〇 In addition, the preform may also comprise a powdered metal material or, in other words, a powder metal tool steel. The bulk of the tool steel is usually solidified or otherwise formed into a plurality of small individual particles, the powder metal is injected into the mold or the powder metal is passed through a die to produce a weakly cohesive powder compact and has been The powder metal tool steel preform is obtained by sintering the powder compact into a body. Tools formed from powder metal tool steel are typically characterized as having isotropic properties as a result of their method of manufacture. However, when processed in accordance with the embodiments disclosed herein, the properties of the tool are improved relative to powder metal tools that are processed according to conventional sintering and/or hot isostatic pressing methods. As disclosed herein, the microstructure of the steel is modified. As in the above cabinet 30, the tool steel is deformed when it contains a Worth. As is known in the art, the Worth field has a face-centered cubic (fec) crystal structure and the martensite has a body-centered bet crystal structure ^ because of its higher number of sliding 138621.doc -16 · 200944596 faces, Those who are familiar with this technology generally believe that the Worth field has higher ductility than martensite. Those of ordinary skill in the art generally recognize that any Worth field formed at temperatures above ac3 is stable. That is, at temperatures above ac3, the Worth field does not normally decompose into other phases. At temperatures below AC3, the Worth field is known to be unstable and is often referred to as metastable because

If it is kept at an extended temperature between AC3 and Ms, it is decomposed into other phases. The Worth field body present in the temperature range described herein is metastable. Although it is not intended to be limited by theory, it is believed to be a residual strain history of the Yassworth Worth (although having the same crystal structure as the Worth). The plastic deformation of the preform containing the metastable Worth field results in a microstructure different from that obtained by quenching the temperature alone or forging the preform at a temperature higher than the AG and then quenching. The resulting microstructure and material properties of the deformed zone may depend on the type of tool steel, the type of thermomechanical processing, the amount of strain induced in the Worth field, the rate at which the strain is induced, and at which temperature the thermomechanical reinforcement is performed. For example, the thermomechanical reinforcement of the metastable Worth field at the temperature between MdACi can produce a microstructure that is different from that produced by the thermomechanical reinforcement of the metastable Worth field at the temperature between Microstructure. However, in any case, the deformed area exhibits improved mechanical properties. As a result of the deformation of the Worth field in these temperature ranges, in one embodiment, the microstructure or grain size in the fine-grained grain-changing region is comparable to that obtained by a conventional process. They are at least 1% less in the middle observations and in another instance - this is about 25%. In the two real towels, the filament microstructure (4) is uniformly precipitated along the carbide phase of more grain boundaries during the process I3862I.doc -17- 200944596. In addition, another microstructure feature can increase the difference in packing density. As is known in the art, the difference is a linear defect in a crystalline solid, such as in the Worth field (5), the anomalous row is formed by the atoms of the additional half of the crystal, and the difference between the other types is known. Many types of differential rows are known to be formed simultaneously in a single crystal. In addition, the grain boundaries can be represented by one or more difference rows. In polycrystalline materials (e.g., tool steel materials for preforms), the grain boundaries present between adjacent crystals are mismatched regions between the crystal lattice of one crystal grain and the crystal lattice of adjacent crystal grains. As the degree of mismatch or misorientation between adjacent grains increases from zero (the crystal structure of adjacent grains is aligned to zero), the difference in density at the grain boundaries increases. Therefore, the measurement of the misorientation angle between the crystal grains is measured as the difference in the density of the discharge, especially the difference in density at the grain boundaries. The area of the deformed tool steel preform is increased to a larger degree than the area where the similar component is deformed by hot forging at a temperature higher than Ac3 or heat treatment according to a conventional method. . The martensite grains after deformation, fire and tempering may be, for example, greater than about 34. The average angle is misorientated, and in another example, the martensite grains are at least about 4 Å. The average orientation error. Moreover, in one embodiment, the difference in area density is at least 2% greater than the hot forged or heat treated portion of the prior art process. For example, the differential row density and grain size can be measured by using electron backscatter diffraction (EBSD) or X-ray diffraction (XRD) techniques. In addition to improving the impact strength of the deformed region, the high differential displacement position may provide a nucleation site for precipitation of the carbide phase during deformation or in subsequent heating or cooling operations. 138621.doc -18- 200944596 The deformed area can also appear in the cross-sectional view of the grain structure area, 曰 疋. In particular, when they are arranged or oriented relative to each other or have a different shape, such that the flow or directionality is good, the surface of the microstructure is provided to the surface of the microstructure. The direction of the other direction of the preferred direction = square: or relative to the direction. In the embodiment, the preferred orientation can be in any direction and the preferred orientation of the die in accordance with the work.

Second, the surface contour of the skull. For example, the preferred orientation may conform to a surface profile formed by substantially: two intersecting surfaces. The grain structure may be substantially parallel to each surface simultaneously transitioning from the first face to the edge of the edge, to the surface, to the second direction (which is parallel to the second table. The initial shape of the preformed crucible ( The presence of a carbide or alloy ribbon in the preformed column prior to processing and processing techniques can be a major factor in determining the preferred orientation of the solar particles in the deformed region. Here, in one embodiment, the deformed region It is characterized by a combination of two or more of the above microjunctions/signals. For example, the deformed region 2 has a grain size distribution with a small average grain size, and the crystal grains can be relative to the working surface or tool axis of the eight In addition, the regions can be characterized as having a relatively high difference in row density. In one embodiment, the regions can be further characterized by a finer, more uniform-distributed carbide phase or in the grains and ruthenium. The phase at the location of the difference in taper. In addition, the characteristics may not vary significantly between locations within the deformed region, although significant variations may exist between two or more independently formed regions. For example, preforming The ρ segment can have a relative height difference separated by a relatively low difference density region. I38621.doc -19- 200944596 degrees: domain. The difference in the difference in density between regions can be attributed to the different l-pass used. (for example, radial forging compared to plane strain forging), different forgings or strengths, different temperatures, etc., : Limited by theory, the inventor is convinced that external energy from thermomechanical machining can be used to stabilize the Vostian The fine grain structure is formed in the bulk phase, and the wild grain structure provides a directional '増 plus difference density or a combination thereof. After quenching, the 'deformed metastable Worth field beneficially affects the final microstructure. In addition, from the heat The external energy of machining can contribute to the sinking of the carbide phase in the microstructure; for example, thermomechanical processing at temperatures below ACi reduces the solubility of carbon in the metastable Worth field, and therefore Promoting carbide slabs. In related embodiments, the carbide phase may precipitate at grain boundaries and/or misalignment sites during deformation or during cooling or during both deformation and cooling. Warm shape In contrast, in addition to other improved properties, the tool steel preforming at a temperature lower than aCi exhibits greater strength. In addition, the increase in the difference in density in the temperature range is higher than in ACi. The thermoformed preformed chain is significantly higher at temperatures compared to the temperature. As explained above, the deformed region of the preform is characterized by a conventional process (eg, heat treatment and/or hot forging at the same temperature as AC3). Compared to improved properties, tools made from tool steel preforms can, for example, exhibit a long service life. Improved properties can include impact strength (according to Charpy test), toughness, hardness, or An improvement in one or more of the wear resistance or a combination thereof. By comparison, the impact strength of the deformed region of the preform of the processed M2 AISI tool steel according to an embodiment of the present invention may be 138621.doc.20 - 200944596 At least 50% higher than tools that are deformed at the temperature of Ah or that are heat treated without forging. In any embodiment, the longer tool life can be attributed to enhanced impact resistance, other stress resistance, or anti-grinding conditions experienced during use. Referring to Figures 2A and 2B and in accordance with another embodiment of the present invention, the tool 18 includes a member 20 having an outer surface 22. The outer surface 22 generally includes a first portion 24 for attachment or coupling to a machine (not shown) and for operation. Surface 26 is a second portion of a representative form that contacts workpiece 28 when tooling 8 is used for metal forming and metal cutting applications. Further, outer surface 22 is closed and defines the outer volume of the tool steel or the outer mass of the body. . As best shown in Figure 2, at least one region 3〇 is formed (as described herein) within the enclosed body volume. Moreover, when region 30 is not comprised of the entire body volume of tool 18, member 20 can have another region 32 that differs from region 3〇 in one or more of the microstructure characteristics, and thus, above The nature of the description is different. In one embodiment, by referring again to FIG. 2A, member 20 is elongated and outer surface 22 defines a barrel or handle 34 that is disposed at one end of handle 34 and has a nose end or body 38 disposed at tip end 40. At the end of the handle 34 opposite the head 36. The working surface 26 carried on the tip 40 engages the side wall 42 of the tip 40 along the cutting edge 44. The cutting edge 44 defines a corner along which the side wall 42 and the working surface 26 meet. The cutting edge 44 and the working surface 26 collectively define a portion of the tool 18 that contacts the surface of the workpiece 28. The workpiece 28 can comprise materials that will be processed by the tool 18 in metal forming or metal cutting applications. When viewed along the longitudinal or centerline 50 of the tool 18, the shank 34 138621.doc 21 · 200944596 has an appropriate cross-sectional profile, such as a circular, rectangular, square cross-sectional wheel temple. The shank 34 and the body 38 can have a cross-sectional profile of the same region, or the body 38 can have a smaller cross-sectional area to provide an undulating region 52 between the shank 34 and the body 38. In certain embodiments, the shank 34 and the body 38 Regarding the midline 5 〇 symmetrical, and in detail 'can have a circular or circular cross-sectional profile centered on the midline 50.

The head 36 of the tool (4) is constructed to be held by a tool holding device for use with a metalworking machine similar to a mechanical or a mechanical machine (not shown). In an exemplary embodiment, the head % is a flange having a diameter greater than the diameter of the shank. However, instead of the head 36, the tool 18 can alternatively include a ball lock, a wedge lock, a turret, or another type of retaining structure for coupling the handle 34 of the tool 18 to the tool holding device. Tool 18, which has a configuration of a punch in a representative embodiment, typically forms a component of module 54. The module 54 further includes a die 56 that contains an opening σ 58 of the portion of the tip end 4G of the receiving tool 18. The die % and the tool (10) are made (when pressed together) to form a shaped hole in the workpiece 28 or at a desired

Mode deformation: Yak 28. The X-piece 18 and die 56 can be removed from the metalworking machine by temporarily attaching the tool 18 to the end of a bumper (not shown) by using a tool holding mechanism. The tool 18 typically moves in a direction 61 toward the workpiece 28 and has a load that is perpendicular to the point of contact between the working surface 26 and the workpiece 28. The metalworking machine can be driven mechanically, hydraulically, pneumatically or electrically to apply a load that forces the tool 8 into the workpiece 28. The tip 40 of the tool 18 is forced through (or into) the thickness of the workpiece 28 under high loads imparted by the metal working machine and into the die opening 58 of 138621.doc -22-200944596. The workpiece 28 is deformed and/or cut at or around the contact strip between the working surface % of the tool 18 and the workpiece 28. Tool 18 can have other punch configurations than those of the representative embodiment. For example, tool 18 can be configured as a blade, a heel punch, a table punch, a round punch, and the like. Although tool 18 is depicted as having a configuration consistent with a punch in a representative embodiment, those skilled in the art will appreciate that tool 18 can have other configurations, such as a die, such as die 56 (Fig. 2a & 2B) or Stripper. In particular, the tool 18 in the form of a punch, die or stripper can be used in metal stamping and forming operations such as perforation and perforation, precision blanking, forming, and extrusion or molding. The tool 18 can also have the construction of a cutting tool such as a rotary broach, a non-rotating broach, a tap, a reamer, a drill bit, a milling cutter, a dressing tool, and the like. Tool 18 can be used in casting and molding applications such as conventional die casting, high pressure die and injection molding. Tool 18 can also be utilized in powder compaction applications used in pharmaceutical manufacturing, health food processing, battery manufacturing, cosmetics, confectionery, and food and beverage industries, as well as household products and nuclear fuels, tablets, explosives, ammunition, ceramics, and other products. In the manufacture. Tool 18 can also be used in automation and part fixture applications such as positioning or part contact elements. Referring to Fig. 2B, region 30 of tool 18, region 62 of die 56 or region 30 of tool 18 and region 62 of die 56 are formed or machined from a thermoformed preformed (not shown) region. As explained above. For example, the 'area 30 is generally located proximate to or includes the working surface 26 such that the region 3〇 approaches or is in direct contact with the workpiece 28 during operation of the tool 18. Similarly, the region 62 of the die 56 approaches the workpiece 28 or is in direct contact with the workpiece 28 when the tool 18 and the die 138621.doc -23. 200944596 die 56 are used. Zone 30 extends from outer surface 22 (e.g., working surface 26) to a depth <1! greater than 〇 039 吋 (1 mm). Similarly, in the die 56, the region 62 may be irregularly shaped, but also extends from the outer surface 63 to a depth greater than 0.039 吋 (1 mm). However, when the region 30 or 62 is formed in the tool steel preform In other locations, 'beneficial performance can be observed. Such locations may be determined by factors such as the use of tool 18 or the use of cost considerations to balance the use of tool 18 with its manufacturing cost. In any aspect, the thermomechanical processing region 30 is characterized by a high differential density, a fine grain structure, a preferred orientation of the grains, or a combination thereof, as provided above. In one embodiment, the high differential charge, fine grain structure, preferred orientation of the grains, or a combination thereof may be associated with the primary direction of deformation during thermo-machining. The tool 18 can have a plurality of regions of high differential density, regions of fine grain structure, regions of preferred orientation of the grains, or regions of combinations thereof. In embodiments having two or more zones, each zone may abut the immediate vicinity of the tool steel preform. It should be understood that the orientation of the grains in a region may or may not be substantially aligned with any of the other regions or the axis of the tool 18. In another embodiment, the region of the high-difference density, the region of the fine grain structure, the region of the preferred orientation of the die, or a combination thereof is substantially throughout and the tool 18 extends rather than being limited to one or more thereof. section. In other words, the tool 18 can be made or formed from preformed mechanical machining of previously thermoformed tool steel in accordance with embodiments herein. Referring to Figures 3A and 3B, although embodiments of the present invention are described and illustrated herein with respect to preforms that are substantially entirely comprised of tool steel, in other embodiments 138621.doc -24- 200944596, the 'preformed culture 64 can be The configuration of the shell 66 made of tool steel having a core μ made of dissimilar steel. As shown in FIG. 3A, along with other variables, a tool (not shown) is fabricated for use; t, the core 68 can fill all or only a portion of the void within the shell 66. Although the volume of the steel in the shell 66 may be smaller than the volume of the dissimilar steel, the shell 66 is greater than the thickness of the 忖.039忖0 such that the deformed region is at least 0.039 (1 sided) thick. The shell 66 is designed to form the working surface 26 of the tool (see Figure 1A). The cores -6 can form the remainder of the tool and can be designed to provide excellent mechanical properties to the tool. By way of example only, the shell 66 can be a harness tube as shown in Figure 3A. Core 68 may be a cylinder made from another steel that is more economical, such as low carbon or cold worked steel, such as D2. After the cylindrical core 68 is inserted into the tubular shell 66, the preform 64 is heated and at least the shell layer % is deformed by swaging or radial forging in the above temperature range. For example, the deformed preform 69 obtained after radially forging the shell 66 and the core 68 is shown in Figure 3β. The boring tool 18a formed or machined from the deformed or forged preform 69 can be used, for example, in applications requiring lateral strength to improve the useful life of the tool (which can include gears (as shown in Figure 3C) or gears Rolling or thread rolling die) 'Although the material cost of the tool is significantly reduced. Further details of the invention will be described in relation to the following examples. Example 1 A diameter having a diameter of 丨5〇〇忖 (3.81 cm) and a length of 48 吋 (1219 cm) was prepared according to an embodiment of the method disclosed herein and is known in the art as AISI M2, D2 And eight tool steel preforms of M4 in the form of rolled bars. 138621.doc -25· 200944596 To this end, the bar is heated in a pneumatic furnace at a temperature above ACi to 21 〇 (rF 〇 M9t). Recorded using a calibrated infrared pyrometer in the operating range. ▲Metrics The microstructure of each of the temperature τ bars contains a Worth field. Once the bar reaches the target temperature, it is individually transferred (to avoid temperature loss during part transfer) to the throat of the throat 4* radial forging machine (10) at r°U). With four reduction processes (re-Uon) will! 5 付 (10) cm) 直径 21.9 cm in diameter x 4) length bars are each radially forged: bars with a diameter of 0.875 (2.222 cm). Each reduction in process cost is between approximately 15 seconds and approximately 20 seconds (each bar totals a maximum of rib seconds). The calculated effective reduction ratio is 66%. The processed bars are forced to convection and air cooled to room temperature. Hot metal will lose heat during thermomechanical processing known to be attributed to losses caused by convection and radiation. Therefore, the temperature of each bar is close to 21 (1) 49. The external heat and internal heat from the deformation process are used to compensate for any heat loss in the narrow temperature range of the target temperature. Therefore, forging is performed under nearly isothermal conditions. In addition, monitoring is done to ensure that any temperature changes are negligible. Eight Cut a small section from each bar during the intermediate reduction process for analysis. No samples were observed to exhibit any recrystallization. In addition, it is determined that the phase present in the sample measures the misorientation between the grains and develops the [001] plane of the I's body with respect to the polar (TD) and radial (RD) polar images. After deformation and subsequent tempering, the two-half Philips X, Pert X-ray diffractometer is obtained at a half of the radius of the cross section of the bar or at about 22 o'clock from the center of the M2 tool steel bar. Phase identification. One of Example 1 138621.doc -26- 200944596 The phase analysis of the M2 bar is shown in Figure 4A. In Figure 4A, the digital fraction for each phase is 0.771473 iron martensite, 0.00419837 chromium-vanadium carbide (658741) '0.219877 iron-tungsten carbide (892579) and 0.00445168 VdC3. The EBSD scan was performed on a field emission environment scanning electron microscope (ESEM)-FEI/Philips XL30 ESEM-FEG with an EBSD detector. The software collection data was collected using the 〇rientation Imaging MicroscopyTM (OMIMM) data and mapped with the XRD data. The error orientation chart is generated by the 0IMTM analysis software. A representative distribution of the wrong directional angles measured for the martensite grains of one of the M2 tool steel bars of Example 1 is shown in Figure 4B. An image of the development of this M2 bar is shown in Figure 4C. Example 2 Several of the 0.875 吋 (2.222 cm) diameter bars from Example 1 were reheated to a temperature of still eight (: 1 to 2100 卞 (1149. (:). The bars were heated to the south by AC! After the 'salt microstructure contains the Worth field. Once the bar reaches the target temperature, it is individually transferred to the inlet roller of the 2 ton 4-hammer radial forging machine. Each bar is at 2100 卞 (1149). Radial forging at the temperature of the crucible. During the four reductions, the diameter of the rod was reduced from 〇875吋 (2·222 cm) to 0.640吋 (1.626 cm except for the first four reductions from the example! In addition to the % reduction, the cross-sectional area is reduced by a 47% effective reduction ratio. The processed bars are forced to convection and air cooled to room temperature. Several samples are cut from a bar at the intermediate reduction process to record the effect of strain. As with the sample from Example 1, recrystallization was not observed in either of the samples. 138621.doc •27- 200944596 As described above, 'balance the heat loss from the environment and the heat generated by self-deformation in an attempt to be hot Maintain the bar at constant during machining Temperature. The temperature is monitored during processing and during the reduction process to ensure that the temperature change is negligible. Therefore all external energy is transferred to the preform to increase the differential density and reduce the grain size of the Worth field. The stress was relieved in a pneumatic furnace at 14 〇〇〇F (76(rc) for four hours and successfully processed by a bar straightener to minimize distortion. Example 3 was prepared with a diameter of 1.500**(3.81 cm) and Eight tool steel preforms of 48 leaf (121.9 cm) length and known in the art as 181 M2, D2 & M42 in the form of rolled bars. The bars are heated in a pneumatic furnace to 2〇5〇卞(1121.(:)The temperature.

But to room temperature. As much as possible, the bar is held at the same temperature as the temperature control described in Examples 1 and 2. In processing, hunting is in place A. The temperature of each of the bars is monitored during processing and during the reduction process to ensure that the temperature change is negligible. 138621.doc -28- 200944596 Cut a small section from each bar during the intermediate reduction process for analysis. None of the samples exhibited microstructural properties of dynamic recrystallization. Determining the phase, obtaining a measure of the misorientation between the grains, and developing the pole of the [001] plane of martensite at a distance of one-half of the radius of the cross-section of the bar or about 0.25 inch from the center of the bar Like a picture. A phase analysis of an M2 rod of Example 3 is shown in Figure 5A. The numerical fraction of the phase in Fig. 5A is 0.737644 iron martensite, 0.0111572 chromium-vanadium carbide (658741), 〇24〇541 iron-tungsten carbide (892579) and 0.0106579 V4C3. A representative distribution of misorientation angles between the martensite grains of one of the example 3iM2 tool steel bars is shown in Figure 5B. A pole figure for the development of this M2 bar is shown in Figure 5C. Comparative Example 1 A rolled AISI M2 bar was heat treated in a 2 bar vacuum furnace using a standard heat treatment cycle by heating the bar to above 2250 °F (about 1232 °C) followed by three heatings. A standard tempering cycle of about 1 Torr and holding for about 45 minutes to 1 hour and cooling is achieved to achieve the same hardness as Examples 丨 and 3, i.e., HRC 61-63. The heat treated bars were then ground to the same outer dimensions as the bars of Example 3. The measurement of the phase of the bar, the misorientation angle and the polar image are shown in Figures 6A, 6B and 6C. The numerical fractions indicated in Figure 6A are 〇·66〇257 iron martensite, 0.00451285 collateral-starved carbide (658741), 〇33〇886 iron crane carbide (892W9) and 0.00434446 VW3. The phase present in each of the bars is substantially the same as that provided by the comparative analysis of Figures 4, 5 and 6 . However, the difference in density of each of the bars of Examples 1 and 3 was significantly higher than that of 138621.doc •29·200944596. Specifically, by comparing the figure and the comparison with FIG. 6B, the error orientation angle of each of the example bars and the 3 bars of 3 is significantly higher than the error of the comparison (10) bar shown in FIG. 6B. To the corner. The average value of the distribution of the misorientation angles of the bars of the real < 歹 U (Fig. 4B) is about 36 degrees. The average value of the distribution of the misalignment angles of the bars of the example 3 (10) B) is about 42 degrees 'and the comparison # The average of the distribution of the misorientation angles of the bars of u (Fig. 6B) is about 34 degrees. The high average misalignment angle of the (4) tool steel bar of the example (4) relative to the comparative heat treated M2 bar indicates a higher difference in density and strain. The deformation of the salt at temperatures below ACl can increase the misorientation angle of the grains compared to the deformation at high temperatures because the grains: less thermal energy and recover from deformation at a slower rate. The improved differential density of the M2 bars of Examples! and 3 is also confirmed by the polar image shown in Figures 4c and 5C, respectively, when compared to the polar image of the comparative example κΜ2 bars shown in Figure 6C. . The pole image indicates that the difference in the post-displacement or the difference in the number of bars of the example (1) is significantly higher than that of the bars of the comparatively heat-treated comparative example. The relative difference in density is indicated by the density of points in each of the graphs. Therefore, the instance i (Fig. 4C) has the highest difference row number, followed by the example 3 (Fig. 5C), and the comparative example 1 (Fig. 6C) has the smallest difference row number. Example 4 Several of the ι·〇〇〇吋(2·54 cm) diameter bars from the procedure of Example 3 were reheated to 2050 F (112 TC) (above AC but below AC3). The rod is removed from the furnace and allowed to air cool to a processing temperature between about 5% (about 5% art) and about 1200 F (about 649 C). Once the processing temperature is reached, the bars are forged radially into seven straight bars with a diameter of 〇〇忖 7〇〇忖 (1 138621.doc -30· 200944596 cm). The calculated reduction ratio is m from two bar air cooling to room temperature. At the intermediate reduction process, the rod exhibits the microstructural properties of dynamic recrystallization. No bars As previously mentioned, the temperature is monitored during processing such as pq ^ 且 and during the reduction process to ensure that the temperature change is negligible. Then temper the bar three times. · About 9 lions in the vacuum furnace (about 5

It takes about 3 hours with the temperature between Jochen F (about 538 t). Confirmed as) The tempering process converts any residual Voss (4) to martensite. It should be noted that in the above example 1-4, 'the processed bars contain grains which are elongated and preferably oriented along the longitudinal axis of the bar." Although Examples 1 through 4 utilize radial forging, it is known in the art. "He forging; ^ technology to thermomechanically process preforms" is described above. Therefore, in the following example, the near-plane strain forging process is repeated on the horizontal hot rod end upswing machine. Forming 65, which will produce cylindrical bars when forged by this machine (see Figures 7 and 8 8 and 8B). Cylindrical bars can then be used as preforms for machining or forming metals Cutting and metal forming tools. Referring to Figures 7, 8A and 8B, in a near-plane strain forging process, the preform 65 geometry consisting entirely of tool steel includes a rectangular section 7〇 and a cylindrical section 72. The cylindrical section 72 does not Subject to any deformation and primarily used to position and hold the preform 65 in the machine during forging. The rectangular section 7 or region is heated and subjected to deformation during processing such that the tool is thereby formed. Molding blank 75 A deformed rectangular section 73 or region, I38621.doc 31 200944596 is best shown in Figure 8B. Referring now to Figure 9, in the near-plane strain forging process, the tool cavity" and the ram 76 are each designed to form a semicircle Mold groove. Collectively, the resulting circular shape formed by the closure of the tool cavity 74 and the ram 76 is designed to prevent the movement of the tool steel in the rectangular section 7 in one direction while allowing the tool steel to flow in the radial and circumferential directions. . • Example 5 A AISI M2 tool steel preform of the geometry illustrated in Figures 7 and 8A was machined from a rolled abrasive bar. The rolling in the conventional abrasive bar 〇 direction or main carbide direction is always concentric with the axis of the cylindrical section, as indicated by the arrows in Figure 4. The orientation of the carbide strip prior to processing determines the orientation of the carbide after thermomechanical processing. Subsequently, the preform was initially annealed at vacuum furnace order = 1400 F (76 ° C) for between 45 minutes and minutes to eliminate any residual stress and obtain a near equiaxed grain structure. After the fire, the rectangular section of each pre-formed fan is heated to a temperature higher than ACi to about 1850 卞 (about 1 〇 1 (rc) using an induction coil. At this processing temperature, the salty microstructure contains the Worth field. Use the infrared pyrometer built into the 5th horizontal bar end forging machine to simulate the near + Q surface strain forging (4) to monitor the temperature. Once the rectangular segment of the preform reaches 185 (TF(lGlGt) ' Each pre-form is individually forged into a nearly semi-circular cross section (see, for example, Figure 8B). After forging, each bar is quenched to room temperature by convection air cooling. The forged microstructure contains fine crystals. After the quenching, the Worth field is transformed into Markov and the carbide sink. It is considered that the microstructure is unstable, 138621.doc 32- 200944596 and it is applied in a vacuum furnace at about 950〇F (Reducing stress at a temperature between about 51 (rc) and about 1 〇〇〇 (about 538 C) and at a pressure of about 2 bar. After stress relief, at about 1200 卞 (about 649 t) and 1400 卞 ( 760. The temperature between the crucibles is 45 to 60 minutes per cycle and the preforms are processed through three tempering cycles. Residual austenite-converted to martensite, followed by furnace cooling to the microstructure of the residual austenite to martensite-converted.

The increase in impact strength obtained from near-plane strain forging is attributed to an increase in the difference in density and a decrease in the grain size of the Worth field. However, unlike the radial forging process, in near-plane strain forging, the heat loss to the environment is negligible because the deformation occurs almost instantaneously along the entire length of the rectangular segment. Example 6 The AISI M2 tool steel of the geometry illustrated in Figure 8At was machined from a rolled abrasive bar to be preformed and then machined. As with the previous preformed chain, the carbide casting direction prior to processing is oriented in a conventional direction (see Figure 7). Prior to heating and deformation, the preform is described as being annealed at 1400 F (76 ° C) in a vacuum oven for between 45 minutes and 6 minutes to eliminate any residual stress in the preform and to obtain a near equiaxed grain structure. . Each of the preforms was heated to a temperature of 2050 F (1121 C) using an induction coil. This temperature is higher than ACi but lower than a. Use an infrared pyrometer to monitor the temperature. Both the coil and the pyrometer are built into the ACMA 50 nozzle horizontal rod end forging machine. The microstructure consists of a Worth field. After heating to eF(u2rc), the rectangular section air is allowed to cool to a temperature between about ι 〇〇卞 (about 59 passages) and about 1200 F (about 649 ° C). The cooling takes place for about i minutes. Microstructure 138621.doc •33- 200944596 Contains a metastable Worth field. The rectangular section is then forged into a circular cross-sectional configuration while maintaining a processing temperature of 1100 卞 (593. 〇 and 1200 卞 (649. (:).) The forged preform is then allowed to cool to room temperature. After cooling, the martensite transformation and carbide precipitation that occurs will result in a homogeneous, fine grain microstructure in the rectangular section of the preform. However, due to the presence of residual Worthfield, the microstructure is considered for most applications. It is unstable. The preform is then tempered three times between 950 卞 (510 〇 and 1000 卞 (538 ° 历 历 45 45 minutes and 60 minutes. Each of the deformed rectangular segments) The increase in impact strength was observed. The increase in impact strength was attributed to the increase in differential discharge density, the decrease in grain size of the Worth field and the initiation of carbide precipitation. Again, similar to the results observed during the radial forging test. The mechanical properties of the forged preforms at temperatures below Aq are improved compared to the mechanical properties of the preforms that are forged at temperatures above ACi. Forging The differential discharge density in the preform is significantly higher than the differential discharge density produced by forging at a higher temperature. Referring to Figures 10A and 10B, although the thermomechanical improved impact strength in the previous exemplary embodiment Due to the intrinsic properties of the near-plane strain forging process, there are relatively high-strength regions and relatively low-strength regions in each rectangular segment. The maximum deformation region and the minimum deformation region are oriented substantially perpendicular to each other. For the purpose of clarity, The preferred orientation of the forged grains is indicated by the curves in Figures 1 and B. The relatively low impact strength regions are typically the areas where they contact the tool cavity and the ram or are located near the tool cavity and the ram. Doc •34- 200944596 The 焉 impact strength zone is about the maximum deformation zone. The cross section shown in Figure 〇A is about 13.11 mm high and about 11.03 mm wide, where the width is from the end of the preform (left The measurement is made to the position where the surface of the deformed rectangular section 73 is transformed into the cylindrical section 72 (right side). • The preform is required to have maximum improvement and near uniform material strength. The planar step strain forging process can be used to continuously improve the strength of the relatively low impact strength region. For example, to obtain a cylindrical rod for metal forming and metal cutting, or thermomechanical treatment, a near bar can be used. Planar strain forging ^••The preforms of the configuration of bars with rectangular or square cross-sectional geometry are thermomechanically treated as bars with elliptical cross-sections to form /, with a circle I The sugar circular cross section of the profile bar followed by thermomechanical processing provides a more uniform distribution of deformation. Specifically, see Figure 1-8, as a result of the first thermomechanical treatment using planar strain forging, relatively low strength The regions will be aligned along or near the smallest deformed region, and the relatively high intensity regions will be aligned relative to the two deformed regions. Therefore, a rectangular or square bar that is forged into an elliptical cross section can be used as a preform for a subsequent near-plane strain forging process. In subsequent processing, the relatively low-strength regions can be aligned in the direction of the highest deformation •. This orientation can be, for example, perpendicular to the initial deformation direction. Therefore, the relatively low-intensity region will be enhanced (as a result of deformation in the region). In contrast, the relatively high strength regions obtained from the first forging operation will observe a minimum deformation strength and thus a minimal improvement. Example 7 Two tools were prepared from a powder metal preform of Ding 15 tool steel. From 138621.doc •35- 200944596 Annealing of thermal turbidity τ15 powder metal machining to obtain preforms (4) Note that the microstructure of the plate is almost isotropic due to its preparation method. The preformed chain has the configuration shown in Figures 11-10. As shown, one end of the preform 76 has a square tapered shape. The measured preform has an overall length of 5.75# (14.6 cm), wherein the square tapered section accounts for 1.75 inch (4.445 cm) of the total length. The preform 76 is heated by an induction heater to a temperature of 20 s (1 〇 93. 〇 and 2050 Τ (1) 21 〇 的 between the A and the AG in about 4 minutes. By having 5 〇〇 tons After the die clamping force, the 预 ton horizontal mechanical AJAX rod end forging machine forges the hot preform into a near net shape in one cycle. The forged preform 78 is shown in Figure UB. , i 75 吋 (4.445 cm) square tapered end forged into i吋 (2 54 cm) rectangular end 80, as shown. After forging, forged 78 in the furnace at 140 ° rF (76 (rc) The stress is relieved between 45 minutes and 60 minutes. The forged preform 78 is then allowed to cool to room temperature in the furnace. The stress-relieved preform is tempered three times to convert the residual Worth field into a horse. The final hardness measured is between 63 1^11 (: and 66 hrC2. The three tempered parts are machined to remove scale, decarb and provide the final tool shape. The preforms shown are cut in half and a set of two tools 18b are produced from the preform configuration shown in Figure UB. 18c. The two tools 1 8b, 18c are operated relative to each other (as indicated by the arrows in Figure 丨丨c), that is, an upper tool and a lower tool to cut the steel sheet 138621.doc -36- 200944596 pieces (not shown). The gap between the tools is 0 006 吋 (〇〇1524 cm). The workpiece is 22MnB5 steel with the eight (8) coating sold under the trademark USIBOR® 1500P. The workpiece steel is pressure hardened to UTS 1500 MPa (50HRC) The steel sheet was measured to be J 85 mm (〇〇7283吋) thick. Tested at approximately 68 F (approximately 20 ° C). The wear at the cutting edge was monitored at four locations. Every 5,000 impacts or cycles Performing the measurement of the cutting edge profile. The edge profile measurements for each of the upper and lower T15 tools are shown in Figures 12A, 13A, 14A and 15A, which also provide reference materials and tools for the CPM® 粕4 end metal. Edge profile. (Tools made of CPM® M4 powdered metal are fully described in Example 8 below.) Although the wear measurements at the four locations on both the upper and lower tools are performed, only the upper and lower jaws are provided in the drawing. The two highest wear positions on the tool Contour measurements are made at the locations indicated in Figures, BE, 14B, and MB. More specifically, Figures 12A and 13A show the upper tool in Figure 12B (bit φ S υ and Figure 13B (position 4), respectively. The pattern of the edge contour of the cutting edge at the position of ^. Further, Figs. 14A and 15A are graphs of the edge contours of the lower tool at the positions specified in the figure (position 1) and Fig. 15B (position 4), respectively. The edge profiles at positions 1 and 4 indicated in the figure illustrate the wear measurements at the remaining two unreported locations. Referring to Figures 12A, 13A, 14A and 15A, the line labeled "Start Edge Geometry" indicates the edge geometry prior to any use. The line labeled "References" indicates the measurement on a tool made from reference materials processed according to industry standards. 138621.doc 200944596 The edge contours at the position of the T15 tool at 10,000 and 20,000 collisions are marked separately. There are &quot;Τ15... 10,000 impacts, and &quot;Τ15 2 times impact.” As shown in the figure, at each position, compared with the reference material of 10,000 impacts on the upper and lower tools, the edge of the Τ15 tool made according to the above procedure is at 1 〇, and the impact at the impact is higher. Less wear and tear. At 20,000 impacts, the Τ15 tool has a wear amount comparable to the amount of wear of the reference material tool at 1 〇. Therefore, the T15 tool according to an embodiment of the present invention provides wear resistance and impact resistance which are almost twice the abrasion resistance and impact resistance of the reference material. Example 8 Two tools were prepared from a powder metal preform of CPM® M4 tool steel. (CPM® is a trademark of Crucible Materials Corp., New York.) Preforms are machined from annealed CPM® M4 powder metal bulk materials. It should be noted that as a result of the rolling direction used to prepare the bulk cpM(g) M4 material, the microstructure of the CPM® M4 board has a predominantly carbonized strip. The preform has a configuration as shown in Figure 11A. As shown, one end of the preform has a square tapered shape. The measured preform has an overall length of 5.75 吋 (146 cm), wherein the square tapered section accounts for 1.75 吋 (4,445 cm) of 5.75 吋 (14.6 cm). The preform was heated to 2000 °F (1093 ° C) and 2050 by means of an induction heater for approximately 4 minutes. The temperature between F (1121.C) (between ACl and AC3). The hot preform was forged into a near net shape in one cycle by a 135, horizontal mechanical ajAX rod end forging machine having a clamping force of 500 stencils. The forged preform is shown in Figure 11B. In particular, ι·75忖 (4 445 138 138621.doc -38- 200944596 m) square tapered ends (shown in Figure 11A) are forged into 丨吋^, "cm" rectangular ends as shown. Thereafter, the preform was subjected to stress relief in a furnace at 1400 = F for 45 minutes and 6 minutes. The preform was then allowed to cool to room temperature in a furnace. The stress-reduced preform was tempered Three times to convert any residual Worth field into martensite. The final hardness measured is between the HRC of 62. The preferred grain orientation in the region of the cut edge of the forged preform of Figure 11B Similar to that shown in Figure 16A, the dimensions of the sample shown in Figure 16A are from top to bottom 17.98 mm and from side to side 1382 mm. According to the edges shown in Figures 12A, nA, 14A and 1SA Profile measurement 'At 10,000 impacts, the CPM® M4 forging tool has less wear than the reference material. Also, significant improvements in tool life have been observed. The description has been made by describing various embodiments. Invention, and although these embodiments have been described in considerable detail, It is the intention of the applicant not to limit the scope of the appended claims to the details or to limit the scope of the appended claims to the details in any way. Those skilled in the art will readily find additional advantages and modifications. The present invention is not limited to the specific details, the representative apparatus and methods, and the illustrative examples shown and described, and thus, without departing from the scope of the general inventive concept of the applicant. Deviation from this detail. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a graphical representation of an exemplary time-temperature relationship for thermomechanically processed M2 AISI tool steel 138621.doc-39-200944596, in accordance with an embodiment of the present invention. 2 is a schematic illustration of other exemplary time-temperature relationships of thermomechanical tool steels in accordance with an embodiment of the present invention. FIG. 2A is a side elevational view of a tool and a cross-sectional view of a corresponding die in accordance with a representative embodiment of the present invention. Figure 2B depicts an enlarged cross-sectional view of the tool and die of Figure 2A. Figure 3A and Figure 3B show the shell and core, respectively, before and after deformation. Figure 3C is a perspective view of an embodiment of the tool made from the deformed preform of Figure 3C. Figures 4A, 4B and 4C are respectively by M2 The measurement of the presence of the phase, the distribution of the misorientation angle of the die, and the diagram of the polar image of an exemplary embodiment of the present invention made by tool steel. Figures 5A, 5B, and 5C are respectively used by the M2 tool. A measurement of the presence of a phase, a distribution of misorientation angles of the grains, and a diagram of a pole image of another exemplary embodiment of the invention made by steel. Figures 6A, 6B and 6C are heat treatments according to prior art, respectively. FIG. 7 is a diagram illustrating an exemplary pre-preparation of a tool for thermomechanical machining of a tool steel according to an embodiment of the present invention. Perspective view of the configuration of the preform. Figure 8A is a plan view of an exemplary preform of crucible 7 prior to processing, in accordance with an embodiment of the present invention. Figure 8B is a partial cross-sectional view of the exemplary preform of Figure 8A after deformation and along section 138621.doc -40-200944596, face line 8B-8B of Figure 7. Figure 9 is a diagrammatic cross-sectional representation of an exemplary die and ram for thermomechanical processing of the preform configurations depicted in Figures 4 and 58. Figure 10A is a photomicrograph taken at a 13X magnification of a cross section obtained from a rectangular cross section of the preform configured as shown in Figure 8B. Figure 10B is an illustration of the photomicrograph of Figure 10A depicting a preferred grain orientation plotted as a curve. 11A and 11B are perspective views, respectively, depicting a configuration of a preform prior to deformation and after deformation and machining. Figure 11C is a perspective view of a set of tools made from the preforms shown in Figure 11B, operatively positioned relative to each other to provide shear or trimming motion for the cutting sheets of the steel material. Figures 12A, 13A, 14A and 15A are wear measurements for illustrating the contours of the cutting edges of the exemplary tool of the present invention and the cutting edges of the tool made of the reference material φ each having the configuration depicted in Figure 11C. A graphical view of the comparison. Figures 12B, 13B, 14B and 15B are plan views of the tool of Figure 11C, which illustrate the measurement positions of the wear wheel temples provided in the charts of Figures 12A, 13A, 14A and 15A. Figure 16A is a photomicrograph taken at a 1X magnified cross-section of the region of the cutting edge of a tool shown in Figure 11B, illustrating preferred grain orientation in the region surrounding the cutting edge. Figure 16B is a photomicrograph of Figure 16A with lines drawn to illustrate preferred grain orientation for 138621.doc 41 200944596. [Major component symbol description] 10 surface processing temperature of AC 1 is higher than MS processing temperature 12 八 与 and gossip processing temperature 13 Ms and processing temperature between gossip 14 carbide nose 16 Bayesian Body nose 18 Tool 18a Tool 18b Tool 18c Tool 20 Member 22 Outer surface 24 First part 26 Working surface 28 Workpiece 30 Area 32 Area 34 Handle 36 Head 38 Body 40 Tip 42 Side wall 138621.doc -42- 200944596

44 Cutting edge 50 Center line 52 Fluctuating area 54 Module 56 Die 58 Opening 61 Direction 62 Area 63 Outer surface 64 Preform 65 Preform 66 Shell 68 Core 69 Preformed field 70 Rectangular section 72 Cylindrical section 73 Rectangular section 74 Tool cavities 75 Preforms 76 Hammers 78 Preforms 80 Rectangular ends di Depth d2 Depth 138621.doc -43

Claims (1)

200944596 VII. Scope of application for patents: ... a kind of thermomechanical plus I - a method comprising pre-forming of a steer steel with a martensite start temperature and a stable Worthian body grade. The region of the field body, the region including an outer surface and a plurality of outer dimensions for the outer surface, the method comprising: adding: a temperature between the start temperature of the martensite and the temperature of the stable wort field: temperature Establishing at least the region of the preform; when the region of the preform/the preform is at the processing temperature, deforming the region to change at least the outer dimensions of the region and the region The structure extends from the outer surface - the depth is modified to a depth of 1 mm or more than 1 millimeter below the outer surface; and after the ι region is deformed, the region is cooled to room temperature. 2. The claim item &gt;&gt; .1 method, wherein after the deformation of the region, the external gauge + Μ of the region is approximately equal to one of the tools used in metal forming or metal cutting applications shape. β, 3. The method of claim 1, wherein the region has a depth extending across the cross-sectional area. a cross-sectional area, and the method of claim 1, wherein the area has a cross-sectional area or the like, and the change is reduced in the at least one of the at least one of the areas, such as the method of claim 1, wherein The ruler of the six-six-six-six-six-story--------------------------------------------- At least - the change in the region increases or decreases the region. 6. The method of requesting the term b, 丄, wherein the microstructure package 138621.doc 200944596 modified by the deformation is determined to be: 34. One of the average misorientation angles is a martensitic grain distributed in one of the characteristic directional angles. 7. 8. 9. As requested in item 1, the degree is kept constant. As in the method of claim 1, the Worth field begins to temperature. The method of claim 8 includes heating the area to a degree. Wherein the processing temperature is increased when the region is deformed, wherein the processing temperature is greater than one of the tool steels, wherein the preforming temperature at the processing temperature does not exceed a temperature of the stable Worth field temperature. The method further comprising: prior to deforming the region, heating the region to a temperature above a starting temperature of the Worth field of the tool steel and cooling the region from the temperature above the temperature at which the Worth field begins To the processing temperature. 11. The method of claim 1, wherein the processing temperature is higher than a starting temperature of a Worth field of the tool steel, and further comprising: maintaining a processing temperature higher than the Worth field when the field 4 is deformed Start temperature. 12. The method of claim i, wherein the processing temperature is between the martensite start temperature and a Worth field start temperature of the tool steel, and further comprising: maintaining the process while the region is deformed The temperature is between the martensite start temperature and the Worth field start temperature. 13. The method of claim i wherein the microstructure of the region does not recrystallize 0 138621.doc 200944596 14. The method of claim </ RTI> further comprising: bonfire the region wherein tempering comprises heating Zone to - does not exceed the temperature of the processing temperature. 15. The method of claim 1, further comprising: • combining a shell made of tool steel and a core made of dissimilar steel before deforming the region, t establishing the temperature at the processing temperature The region includes establishing at least the shell layer at the processing temperature and deforming at least a portion of the shell layer when the shell layer is at the processing temperature. 16. A tool for use in a machine to modify a defensive member, the tool comprising: 'a member comprising a tool steel, the member having an outer surface, the outer surface defining a configuration to The first portion of the coupling of the machine and a second portion adapted to contact the workpiece and the member includes a first region extending from the outer surface to a depth greater than 1 mm and a region by the first region The outer surface is separated by a second region, the first region comprising a plurality of greater than about 34. The plurality of dies having a mean misorientation angle that is one of the characteristic misorientation angles has an average grain size that is at least 1% less than the average grain size of the second region, and has the second A grain orientation with a plurality of different grains in the region. 17. The tool of claim 16, wherein the average misorientation angle is at least about 40°. 18. The tool of claim 16 wherein the first region is adjacent to the second portion of the outer surface. 19. The implement of claim 16, wherein the microstructure of the first region is not crystallized by further 138621.doc 200944596. 20. The tool of claim 16, wherein the member comprises a shell made of tool steel and a core made of dissimilar steel, the shell having the outer surface defining the first portion and the core forming the At least a portion of the second region. 138621.doc -4-