WO2022210874A1 - Mold and method for manufacturing hot-press molded article - Google Patents
Mold and method for manufacturing hot-press molded article Download PDFInfo
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- WO2022210874A1 WO2022210874A1 PCT/JP2022/015965 JP2022015965W WO2022210874A1 WO 2022210874 A1 WO2022210874 A1 WO 2022210874A1 JP 2022015965 W JP2022015965 W JP 2022015965W WO 2022210874 A1 WO2022210874 A1 WO 2022210874A1
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- width
- rib portion
- mold
- hot press
- slow cooling
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- 238000004519 manufacturing process Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims description 38
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Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/20—Deep-drawing
- B21D22/208—Deep-drawing by heating the blank or deep-drawing associated with heat treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/02—Stamping using rigid devices or tools
- B21D22/022—Stamping using rigid devices or tools by heating the blank or stamping associated with heat treatment
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D22/00—Shaping without cutting, by stamping, spinning, or deep-drawing
- B21D22/20—Deep-drawing
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D24/00—Special deep-drawing arrangements in, or in connection with, presses
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21D24/00—Special deep-drawing arrangements in, or in connection with, presses
- B21D24/005—Multi-stage presses
Definitions
- the present disclosure relates to a mold and a method for manufacturing a hot press-formed product using the mold.
- hot press forming the material is heated to a temperature range where the microstructure becomes an austenite single phase. Then, the heated raw material is hot press-molded using a hot press device equipped with a mold. In hot press molding, the material is softened by heating. Therefore, the press formability of the material in hot press forming is high. In hot press forming, the material being hot pressed also contacts substantially the entire forming surface of the mold. At this time, the material is quenched by removing heat from the metal mold that is in contact with the material. Thus, in hot press forming, the material is hot press formed and quenched at the same time. Therefore, hot press-molding can easily produce a high-strength hot-press-molded product.
- a heated material is hot press molded using a mold.
- the material is partially quenched by flowing a coolant through part of the gap between the mold and the material.
- the mold of Patent Document 1 has a supply port on the surface of the mold for supplying the coolant in the coolant passage inside the mold to the outside of the mold.
- the mold of Patent Document 1 further includes a convex portion that contacts a boundary region between the high-strength portion and the low-strength portion of the material.
- a coolant is supplied from the supply port to the gap between the high-strength portion and the mold.
- the coolant is not supplied to the gap between the low-strength portion and the mold.
- a hot press-formed product having a low-strength portion with excellent shock absorption ability can be manufactured.
- a hot press-formed product having excellent impact absorption ability may be produced by other techniques different from the technique described in Patent Document 1.
- An object of the present disclosure is to provide a mold capable of producing a hot press-formed product having excellent impact absorption ability by hot press molding, and a method for producing a hot press-formed product using the mold. That is.
- a mold according to the present disclosure is a mold for performing hot press molding on a material.
- the mold includes an upper mold and a lower mold.
- the upper mold has a first molding surface.
- the lower mold has a second molding surface.
- the second molding surface is arranged to face the first molding surface during hot press molding, and together with the first molding surface hot press mold the material.
- the first molding surface includes a first slow cooling region.
- the first slow cooling region has a plurality of first ribs and a plurality of first grooves.
- the plurality of first rib portions are arranged in the width direction of the first rib portion.
- the plurality of first grooves are arranged in the width direction of the first grooves.
- the first rib is formed between adjacent first grooves.
- the width of the first rib portion is narrower than the width of the first groove portion.
- the second molding surface includes a second slow cooling region.
- the second slow cooling region has a plurality of second rib portions and a plurality of second groove portions.
- the plurality of second rib portions are arranged in the width direction of the second rib portions.
- the plurality of second grooves are arranged in the width direction of the second grooves.
- the second rib is formed between adjacent second grooves.
- the width of the second rib portion is narrower than the width of the second groove portion.
- the method for manufacturing a hot press-formed product includes the steps of preparing a material, heating the prepared material to a temperature of A c 3 or more, and applying the heated material with the above-described mold. It comprises a step of performing hot press molding, and a step of releasing the hot press-molded material from the mold to produce a hot press-molded product.
- a mold according to the present disclosure can produce a hot press-formed product having excellent impact absorption capability by hot press-forming.
- the method for producing a hot press-formed product according to the present disclosure can produce a hot press-formed product having excellent impact absorption capacity.
- FIG. 1 is a front view showing an example of a hot press device for hot press molding.
- FIG. 2 is a perspective view showing an example of the mold according to this embodiment.
- FIG. 3 is a cross-sectional view showing the state of the mold and material during hot press molding in the slow cooling region of an example of the mold according to the present embodiment.
- FIG. 4 is a cross-sectional view showing the state of the mold and the material during hot press molding in the quench region of an example of the mold according to this embodiment.
- FIG. 5A is an enlarged schematic diagram of region 100 in FIG.
- FIG. 5B is a schematic diagram of FIG. 5A excluding material B, showing the time of hot press molding.
- FIG. 5A is an enlarged schematic diagram of region 100 in FIG.
- FIG. 5B is a schematic diagram of FIG. 5A excluding material B, showing the time of hot press molding.
- FIG. 5C is a cross-sectional view perpendicular to the extending direction of the first rib portion or the second rib portion having a shape different from that of FIGS. 5A and 5B.
- FIG. 5D is a cross-sectional view perpendicular to the extending direction of the first rib portion or the second rib portion having a shape different from that of FIGS. 5A to 5C.
- FIG. 6 is a schematic diagram of the region 100 of FIG. 3 as viewed from above (the normal direction of the first slow cooling region and the second slow cooling region).
- FIG. 7 is a schematic diagram enlarging the region 200 in FIG. FIG.
- FIG. 8 is a diagram showing the relationship between Fn1 and the temperature variation ⁇ T (° C.) in the first slow cooling region and the second slow cooling region.
- FIG. 9 is a schematic diagram of the heat conduction model used in the two-dimensional heat transfer simulation for creating FIG.
- FIG. 10 is a diagram showing the relationship between Fn2 and the cooling rate V (°C/sec) of material B during hot press molding.
- FIG. 11 is a perspective view showing another example different from FIG. 2 of the mold according to this embodiment.
- FIG. 12 is a perspective view showing another example of the mold according to this embodiment, which is different from FIGS. 2 and 11.
- FIG. 13 is a perspective view showing another example different from FIGS. 2, 11 and 12 of the mold according to this embodiment.
- FIG. 14 is another example different from FIG.
- FIG. 5A among schematic diagrams in which the region 100 in FIG. 3 is enlarged.
- 15 is a cross-sectional view taken along the line segment XV-XV in FIG. 14.
- FIG. FIG. 16 is another example different from FIGS. 5A and 14 in a schematic diagram in which the region 100 in FIG. 3 is enlarged.
- FIG. 17 is a schematic diagram showing only the rib portion when viewing the region 100 of FIG. 16 from the normal direction of the first slow cooling region.
- FIG. 18 is another example different from FIGS. 5A, 14, and 16 in the enlarged schematic diagram of the region 100 in FIG.
- FIG. 19 is a schematic diagram showing only the rib portion when viewing the region 100 of FIG. 18 from the normal direction of the first slow cooling region.
- impact absorption members are required to have improved impact energy absorption capacity at the time of a collision, that is, improved impact absorption capacity.
- Impact energy is absorbed by plastic deformation of the structural member. Therefore, in order to improve the impact absorption ability, it is effective to exhibit excellent plastic deformation ability even when subjected to high stress.
- the present inventors thought that if the cooling rate of the material during hot press molding could be reduced, the material would be able to exhibit excellent plastic deformability even when subjected to high stress. Therefore, the present inventors investigated the surface shape of the molding surface of the mold. As a result, the present inventors considered that the cooling rate of the material during hot press-forming can be reduced by forming a slow-cooling region including a plurality of ribs and a plurality of grooves on the molding surface.
- the rib portion extends in a predetermined direction, and has a convex cross section perpendicular to the extending direction.
- the groove extends along the extending direction of the rib, and has a concave cross section perpendicular to the extending direction. The plurality of rib portions and the plurality of groove portions are alternately formed.
- the rib part directly contacts the material in the slow cooling region to remove heat from the material.
- the groove does not come into direct contact with the material. Therefore, if the molding surface includes a plurality of ribs and a plurality of grooves, it is possible to reduce the contact area between the mold and the material during hot press molding. Therefore, the cooling rate of the material during quenching can be reduced.
- the present inventors focused on the width of the rib and the width of the groove among the plurality of ribs and the plurality of grooves in the slow cooling region of the molding surface of the mold, and further examined in detail. As a result, the present inventors have found that if the width of the rib portion is narrower than the width of the groove portion, heat dissipation from the material during hot press forming can be effectively reduced, and the cooling rate can be reduced. If the cooling rate of the material during hot press molding can be slowed down, the increase in strength of the material can be suppressed, and the impact absorption capacity can be enhanced.
- the width of the rib portion in the slow cooling region narrower than the width of the groove portion, it is possible to form an impact buffering region with reduced strength in at least a portion of the hot press-formed product.
- the width of the rib portion is narrower than the width of the groove portion, wavy deformation occurs on the surface of the hot press-formed product, which may reduce the dimensional accuracy of the hot press-formed product. Therefore, the present inventors investigated the cause of this. As a result, the present inventors obtained the following findings.
- the ribs formed in the slow cooling region of the molding surface of one of the pair of molds cool the molding surface of the other mold. It may enter the groove formed in the region. In this case, the above-described wavy deformation occurs on the surface of the hot press-formed product.
- the present inventors have found that during hot press molding, the rib portion formed in the slow cooling region of one mold and the rib portion formed in the slow cooling region of the other mold and overlap when viewed from the normal direction of the slow cooling region. If at least a part of the rib formed in the slow cooling region of one mold overlaps with the rib formed in the slow cooling region of the other mold, the rib can be prevented from entering the groove. can be suppressed.
- the rib portion formed in one slow cooling region and the other slow cooling region At least a part overlaps with the formed rib portion.
- the mold according to the present embodiment completed based on the above knowledge and the method for manufacturing a hot press-formed product using the mold according to the present embodiment have the following configurations.
- a mold for performing hot press molding on a material an upper mold having a first molding surface; a lower mold having a second molding surface that is arranged to face the first molding surface and hot press molds the material together with the first molding surface during hot press molding;
- the first molding surface is including a first slow cooling region having a plurality of first ribs and a plurality of first grooves;
- the plurality of first rib portions are arranged in the width direction of the first rib portion,
- the plurality of first grooves are arranged in the width direction of the first grooves,
- the first rib portion is formed between the adjacent first groove portions,
- the width of the first rib portion is narrower than the width of the first groove portion,
- the second molding surface is including a second slow cooling region having a plurality of second ribs and a plurality of second grooves;
- the plurality of second rib portions are arranged in the width direction of the second rib portion,
- the plurality of second grooves are arranged in the width direction of the second
- the mold of [1] can produce a hot press-formed product with excellent impact absorption capability by hot press-forming.
- the mold of [2] can improve the accuracy of the simulation of heat transfer in the material during hot press molding.
- the width of the first rib portion is 10 to 50% of the width of the first groove portion
- the width of the second rib portion is 10 to 50% of the width of the second groove portion
- the cooling rate can be slowed during hot press molding. If the cooling rate can be slowed down, it becomes easier to stop cooling at a desired material temperature. For example, during hot press forming, cooling is stopped between the Mf point and the Ms point, and then the heating and holding step described later is performed to generate martensite and retained austenite in the microstructure of the material. You can adjust the amount. Further, for example, during hot press molding, cooling is stopped at a temperature between Ms point and 500 ° C., and then a heating and holding step described later is performed, so that the microstructure of the material is mainly bainite. It can be an organization.
- the mold of [4] can suppress the temperature variation of the material during hot press molding.
- the width of the first rib portion is 10 to 50% of the width of the first groove portion
- the width of the second rib portion is 10 to 50% of the width of the second groove portion
- the width of each of the first rib portion and the second rib portion is 1.0 to 8.0 mm
- Each height of the first rib portion and the second rib portion is 0.2 to 5.0 mm
- Fn1 defined by formula (1) is 14 or less
- Fn1 Wr0.9 / P00.8 +0.05Hr (1)
- Wr in the formula (1) is the width (mm) of the first rib portion and the second rib portion
- P0 Wr/Ws
- Ws is the width of the first groove portion and the second groove portion.
- Hr is the height (mm) of the first rib portion and the second rib portion.
- the mold of [5] can further suppress the temperature variation of the material during hot press molding.
- the width of the first rib portion is 10 to 50% of the width of the first groove portion
- the width of the second rib portion is 10 to 50% of the width of the second groove portion
- the width of each of the first rib portion and the second rib portion is 1.0 to 8.0 mm
- Each height of the first rib portion and the second rib portion is 0.2 to 5.0 mm
- Fn2 defined by formula (2) is 30 or more, Mold.
- Ws in the formula (2) is the width (mm) of the first groove portion and the second groove portion
- Wr is the width (mm) of the first rib portion and the second rib portion
- Hr is the height (mm) of the first rib portion and the second rib portion.
- the cooling speed of the material can be made slower. If the cooling rate can be slowed down, it becomes easier to stop cooling at the desired material temperature. For example, during hot press forming, cooling is stopped between the Mf point and the Ms point, and then the heating and holding step described later is performed to generate martensite and retained austenite in the microstructure of the material. You can adjust the amount. Further, for example, during hot press molding, cooling is stopped at a temperature between Ms point and 500 ° C., and then a heating and holding step described later is performed, so that the microstructure of the material is mainly bainite. It can be an organization.
- the mold of [7] can further suppress the temperature variation of the material during hot press molding.
- a method for manufacturing a hot press-formed product a process of preparing materials; heating the prepared material to a temperature of A c 3 or higher; A step of performing hot press molding on the heated material using the mold according to any one of [1] to [7]; A step of releasing the hot press-formed material from the mold to produce a hot press-formed product; A method for producing a hot press-formed product.
- the method for producing a hot press-formed product in [8] can produce a hot press-formed product with excellent impact absorption capability.
- FIG. 1 is a front view showing an example of a hot press machine 1 for hot press molding.
- a hot press machine 1 has substantially the same configuration as a known hot press machine, except for a mold 10 according to this embodiment.
- a hot press device 1 includes a frame 2, a slide 3, a bolster 4, and a die 10 (upper die 11 and lower die 12).
- the vertical (vertical) direction of the hot press machine 1 is also called the V direction
- the width direction of the hot press machine 1 is also called the W direction
- the V direction and the direction perpendicular to the W direction are also called the L direction.
- the frame 2 is arranged on the upper part of the hot press device 1.
- the frame 2 supports a slide 3 arranged below the frame 2 so as to be able to move up and down.
- the frame 2 has a drive (not shown) for raising and lowering the slide 3 .
- the drive may be a mechanical mechanism or a hydraulic mechanism.
- the slide 3 is attached to the frame 2 and can be vertically moved by a driving device provided in the frame 2 .
- An upper die 11 is attached to the lower surface of the slide 3 .
- a bolster 4 is arranged below the slide 3 .
- the upper surface of bolster 4 faces the lower surface of slide 3 .
- a lower mold 12 is attached to the upper surface of the bolster 4 . At this time, the lower mold 12 is arranged below the upper mold 11 .
- the mold 10 includes the upper mold 11 described above and the lower mold 12 described above.
- the upper die 11 and the lower die 12 extend in the L direction in FIG.
- the direction in which the upper die 11 and the lower die 12 extend is also referred to as "longitudinal direction (L direction) of the die 10".
- L direction and the direction perpendicular to the V direction in FIG. 1 are also referred to as the "width direction (W direction) of the mold 10".
- the upper mold 11 is fixed to the lower surface of the slide 3 and the lower mold 12 is fixed to the upper surface of the bolster 4 .
- the lower mold 12 is arranged below the upper mold 11 .
- a heated material blade
- the upper die 11 slides in the V direction relative to the lower die 12 and applies an external force to the material while being in contact with the material.
- the upper mold 11 and the lower mold 12 hot press mold the material. Thereby, the material is formed into a desired shape.
- the molding surface of the upper mold 11 and the molding surface of the lower mold 12 come into contact with the material, and the upper mold 11 and the lower mold 12 remove heat from the material and harden it. Therefore, a hot press-formed product having a desired shape and enhanced strength is manufactured.
- the hot press device 1 may include a configuration not shown in FIG.
- the hot press device 1 may include, for example, a cooling device for cooling the mold 10 .
- a flow path through which the cooling medium passes is provided inside the mold 10 .
- a pump for supplying a cooling medium inside the mold 10 is arranged.
- the hot press device 1 may further include a transport mechanism for transporting the material to the hot press device 1 .
- the hot press device 1 may have a configuration not shown in FIG. 1, which is provided in a known hot press device.
- FIG. 2 is a perspective view of the mold 10 in FIG. 1.
- upper mold 11 has first molding surface 110 .
- the first molding surface 110 is arranged on the lower surface of the upper mold 11 .
- the first molding surface 110 includes a concave portion extending in the L direction in the central portion in the W direction.
- the lower mold 12 has a second molding surface 120.
- the second molding surface 120 is arranged on the upper surface of the lower mold 12 .
- the second molding surface 120 includes a convex portion extending in the L direction at the central portion in the W direction.
- the second molding surface 120 is arranged to face the first molding surface 110 .
- the second molding surface 120 and the first molding surface 110 are brought into contact with the material (blank) to hot press mold the material.
- the first molding surface 110 includes a first slow cooling region 113 indicated by hatching.
- the first slow cooling region 113 is formed on a portion of the first molding surface 110 .
- first forming surface 110 includes first slow cooling region 113 and first quenching region 114 .
- the second molding surface 120 includes a second slow cooling region 123 indicated by hatching.
- the second slow cooling region 123 is formed on a portion of the second molding surface 120 .
- second molding surface 120 includes second slow cooling region 123 and second quenching region 124 .
- the first quench zone 114 faces the second quench zone 124 .
- the first rapid cooling region 114 and the second rapid cooling region 124 form high-strength regions having high strength in the material (hot press-formed product) after hot press-forming.
- the first slow cooling region 113 faces the second slow cooling region 123 .
- the first slow-cooling region 113 and the second slow-cooling region 123 are impact-absorbing regions that have a lower strength than the high-strength region and are prone to plastic deformation in the material (hot press-formed product) after hot press forming. Form.
- FIG. 3 is a cross-sectional view including the V direction and the W direction showing the state of the mold 10 and the material (blank) B in the first slow cooling region 113 and the second slow cooling region 123 during hot press molding.
- FIG. 4 is a cross-sectional view including the V direction and the W direction showing the state of the mold 10 and the material B in the first quenching region 114 and the second quenching region 124 during hot press molding.
- 3 and 4 show the state in which the upper mold 11 reaches the bottom dead center and the mold 10 is closed.
- FIGS. 3 and 4 show that substantially the entire first molding surface 110 of the upper mold 11 and substantially the entire second molding surface 120 of the lower mold 12 are in contact with the material B, and are attached to the material B. It shows the state in which an external force is applied.
- material B is sandwiched between upper mold 11 and lower mold 12 during hot press molding. At this time, the concave portion of the first molding surface 110 fits into the convex portion of the second molding surface 120 . As a result, the material B is formed into a hat-shaped hot press-formed product.
- the mold 10 of FIG. 2 further includes slow cooling regions (113 and 123) and rapid cooling regions (114 and 124).
- the surface structure of the first slow cooling region 113 forming the impact buffering region of the hot press-formed product is the same as that of the first rapid cooling region forming the high-strength region of the hot press-formed product.
- 114 surface structure On the second molding surface 120 of the lower die 12, the surface structure of the second slow-cooling region 123 forming the impact buffering region of the hot press-formed product is different from that of the second slow cooling region 123 forming the high-strength region of the hot press-formed product. 2 different from the surface structure of the quench zone 124;
- the surface structures of the first molding surface 110 and the second molding surface 120 are further described below.
- first molding surface 110 [Configuration of first slow cooling region 113]
- 5A is an enlarged view of the region 100 within the first slow cooling region 113 of the first molding surface 110 in FIG. 3.
- FIG. 5A first slow cooling region 113 of first molding surface 110 of upper mold 11 has a plurality of first rib portions 111 and a plurality of first groove portions 112 .
- FIG. 6 is a schematic diagram of the region 100 of FIG. 3 as viewed from above (the normal direction of the first slow cooling region 113 and the second slow cooling region 123).
- the plurality of first rib portions 111 extend in a predetermined direction. In FIGS. 5A and 6, as an example, the multiple first rib portions 111 extend in the L direction. However, the extending direction of the plurality of first rib portions 111 is not limited to the L direction.
- the plurality of first rib portions 111 are arranged in the width direction of the first rib portions 111 .
- the width direction of the first rib portion 111 is a direction perpendicular to the extending direction of the first rib portion 111 .
- the width direction of the first rib portion 111 is the W direction.
- the width direction of the first rib portion 111 is not limited to the W direction.
- each first rib portion 111 extends in the L direction and is arranged in the W direction.
- the plurality of first grooves 112 are arranged in the width direction of the first grooves 112, and the first ribs 111 are formed between adjacent first grooves 112. As shown in FIG. In FIG. 5A, the first grooves 112 extend in the L direction and are arranged in the W direction, like the first ribs 111 . Furthermore, the first rib portion 111 is formed between two adjacent first groove portions 112 . 5A, the plurality of first grooves 112 and the plurality of first ribs 111 both extend in the L direction, and the first grooves 112 and the first ribs 111 are alternately arranged in the W direction.
- the width of first rib portion 111 is narrower than the width of first groove portion 112 .
- the width of the first rib portion 111 means the width of the first rib portion 111 in a cross section perpendicular to the extending direction of the first rib portion 111 .
- the width of the first rib portion 111 means the width of the first rib portion 111 in the W direction.
- the width of the first groove portion 112 means the width of the first groove portion 112 in a cross section perpendicular to the extending direction of the first groove portion 112 .
- the width of the first groove portion 112 means the width of the first groove portion 112 in the W direction.
- the width of the first rib portion 111 and the width of the first groove portion 112 can be easily determined using, for example, vernier calipers.
- the width of first rib portion 111 is narrower than the width of first groove portion 112 .
- the heat removal amount in the first groove portion 112 is smaller than the heat removal amount in the first rib portion 111 . Since the width of the first rib portion 111 is narrower than the width of the first groove portion 112, the amount of heat removal in the first rib portion 111 can be reduced. Therefore, in the first slow cooling region 113 , the cooling rate of the material B can be made slower than in the first rapid cooling region 114 .
- the degree of quenching of the region of the material B that is in contact with the first slow cooling region 113 can be reduced.
- the material B (hot press-formed product) after hot press-forming can be formed with a shock absorbing region with reduced strength.
- FIG. 7 is an enlarged view of area 200 in first quench zone 114 of first forming surface 110 of FIG.
- first rib portion 111 and first groove portion 112 are not formed in first rapid cooling region 114 of first molding surface 110 of upper mold 11 .
- the first quench region 114 of the first molding surface 110 is a smooth surface. Therefore, substantially the entire first quench region 114 is in contact with the material B during hot press forming. Therefore, in the first rapid cooling region 114 , the cooling rate of the material B can be made faster than in the first slow cooling region 113 .
- the degree of quenching of the area of the material B that is in contact with the first rapid cooling area 114 can be increased. As a result, it is possible to form a high-strength region having a higher strength than the impact buffer region in the material B (hot press-formed product) after hot press-forming.
- second slow cooling region 123 of second molding surface 120 of lower die 12 has a plurality of second rib portions 121 and a plurality of second groove portions 122 .
- the plurality of second rib portions 121 extend in a predetermined direction.
- the plurality of second rib portions 121 extend in the L direction.
- the extending direction of the plurality of second rib portions 121 is not limited to the L direction.
- the plurality of second rib portions 121 are arranged in the width direction of the second rib portions 121 .
- the width direction of the second rib portion 121 is a direction perpendicular to the extending direction of the second rib portion 121 .
- the width direction of the second rib portion 121 is the W direction.
- the width direction of the second rib portion 121 is not limited to the W direction.
- the second rib portions 121 extend in the L direction and are arranged in the W direction.
- the plurality of second grooves 122 are arranged in the width direction of the second grooves 122, and the second ribs 121 are formed between the adjacent second grooves 122.
- the second grooves 122 extend in the L direction and are arranged in the W direction, like the second ribs 121 .
- the second rib portion 121 is formed between two adjacent second groove portions 122 .
- the plurality of second grooves 122 and the plurality of second ribs 121 both extend in the L direction, and the second grooves 122 and the second ribs 121 are alternately arranged in the W direction.
- the width of the second rib portion 121 is narrower than the width of the second groove portion 122 .
- the width direction of the second rib portion 121 and the second groove portion 122 corresponds to the width direction (W direction) of the mold 10 . Therefore, in the cross section shown in FIG. 5A, the width of the second rib portion 121 means the width of the second rib portion 121 in the W direction, and the width of the second groove portion 122 means the width of the second groove portion 122 in the W direction.
- the width of the second rib portion 121 and the width of the second groove portion 122 can be determined using, for example, vernier calipers.
- the width of second rib portion 121 is narrower than the width of second groove portion 122 .
- the width of the second rib portion 121 means the width of the second rib portion 121 in a cross section perpendicular to the extending direction of the second rib portion 121 . Therefore, the same effect as the relationship between the width of the first rib portion 111 and the width of the first groove portion 112 described above can be obtained. Specifically, when the second slow-cooling region 123 comes into contact with the material B during hot press-forming, the heat removal amount in the second groove portions 122 is less than the heat removal amount in the second rib portions 121 .
- the width of the second rib portion 121 is narrower than the width of the second groove portion 122, the amount of heat removal in the second rib portion 121 can be reduced. Therefore, in the second slow cooling region 123, the cooling rate of the material B can be made slower than in the second rapid cooling region 124, which will be described later. Therefore, when hot press forming is performed using the mold 10, the degree of quenching of the area of the material B that is in contact with the second slow cooling area 123 can be reduced. As a result, the material B (hot press-formed product) after hot press-forming can be formed with a shock absorbing region with reduced strength.
- second rib portion 121 and second groove portion 122 are not formed in second rapid cooling region 124 of second molding surface 120 of lower die 12 . That is, the second quench region 124 of the second molding surface 120 is a smooth surface. Therefore, substantially the entire second quench region 124 is in contact with the material B during hot press forming. Therefore, in the second rapid cooling region 124 , the cooling rate of the material B can be made faster than in the second slow cooling region 123 . Therefore, when hot press forming is performed using the mold 10, the degree of quenching of the area of the material B that is in contact with the second rapid cooling area 124 can be increased. As a result, it is possible to form a high-strength region having a higher strength than the impact buffer region in the material B (hot press-formed product) after hot press-forming.
- first rib portion 111 and second rib portion 121 [Relationship between first rib portion 111 and second rib portion 121] Further, in the mold 10, during hot press molding, the first slow cooling region 113 of the first molding surface 110 and the second slow cooling region 123 of the second molding surface 120 are arranged in the normal direction of the first slow cooling region 113. When viewed from above, the first rib portion 111 and the second rib portion 121 at least partially overlap.
- “at the time of hot press molding” means that substantially the entire molding surface 110 of the upper mold 11 and substantially the entire molding surface 120 of the lower mold 12 come into contact with the material B and apply an external force to the material B. It means a state in which the mold 10 is closed and the material B is cooled by the mold 10 while the upper mold 11 is held at the bottom dead center.
- the first rib portion 111 does not enter the second groove portion 122 and the second rib portion 121 does not enter the first groove portion 112 during hot press molding. Therefore, during hot press forming, the first rib portion 111 enters the second groove portion 122 or the second rib portion 121 enters the first groove portion 112, thereby preventing the material B from being deformed into a wavy shape. can be suppressed.
- the width of the first rib portion 111 of the first slow cooling region 113 is narrower than the width of the first groove portion 112 . Furthermore, the width of the second rib portion 121 in the second slow cooling region 123 is narrower than the width of the second groove portion 122 . Therefore, when hot press molding is performed using the mold 10 , the cooling rate is suppressed in the area of the material B sandwiched between the first slow cooling area 113 and the second slow cooling area 123 . Therefore, in the hot press-formed product, it is possible to form a shock buffering region with reduced strength and a high-strength region with a higher strength than the shock buffering region.
- the first rib portion 111 and the second rib portion 121 overlap at least partially. Therefore, it is possible to suppress the material B from deforming into a wavy shape in the impact buffering region.
- the first rib portion 111 and the second rib portion 121 preferably extend in the same direction. Moreover, the first groove 112 and the second groove 122 extend in the same way. 5A and 6, the first rib portion 111 and the second rib portion 121 extend in the L direction, and the first groove portion 112 and the second groove portion 122 extend in the L direction.
- the heat transfer simulation of the material B is , it suffices to carry out a simulation in two dimensions. That is, if a two-dimensional simulation is performed on a cross section perpendicular to the extending direction of the first rib portion 111, the first groove portion 112, the second rib portion 121, and the second groove portion 122 (that is, the cross section shown in FIG. 5A), , the results are substantially the same as those obtained by three-dimensional simulations. Therefore, there is no need to perform a three-dimensional simulation. Therefore, the heat transfer of the material B can be easily and accurately simulated. That is, the cooling rate can be controlled more easily and accurately. In this case, it is possible to control the chemical composition of material B to a desired microstructure by using a simulation.
- the hot press-formed product when material B is steel, as a result of hot press molding of material B, if the hot press-formed product has a microstructure containing not only a hard phase but also retained austenite, the impact of the hot press-formed product Further increases the absorption capacity.
- the hard phase consists of martensite and/or bainite.
- the width of the first rib portion 111 formed in the slow cooling region 113 is 10 to 50% of the width of the first groove portion 112
- the width of the second rib portion 121 formed in the slow cooling region 123 is , 10 to 50% of the width of the second groove portion 122 .
- the width of the first rib portion 111 is 10% or more of the width of the first groove portion 112
- the first rib portion 111 removes heat from the material B appropriately. In this case, it is possible to prevent the cooling rate of the material B from becoming excessively slow. Therefore, the formation of ferrite and pearlite in the microstructure of material B can be suppressed, and the formation of hard phase or hard phase and retained austenite is promoted. As a result, the impact absorption capacity of the hot press-formed product is improved.
- the cooling rate can be slowed down during hot press molding. If the cooling rate can be slowed down, it becomes easier to stop cooling at a desired material temperature. For example, cooling may be stopped between the Mf point and the Ms point to adjust the amount of martensite and retained austenite produced. For example, the cooling may be stopped at a temperature higher than the Ms point, and the microstructure of the material may be made mainly of bainite.
- the width of the first rib portion 111 is 10-50% of the width of the first groove portion 112 . More preferably, the upper limit of the ratio of the width of the first rib portion 111 to the width of the first groove portion 112 is 45%, more preferably 40%, and even more preferably 35%. A more preferable lower limit of the ratio of the width of the first rib portion 111 to the width of the first groove portion 112 is 12%, more preferably 14%.
- FIG. 5B is a schematic diagram of FIG. 5A excluding material B, showing the time of hot press molding.
- the width of the first rib portion 111 is defined as follows. Of the surfaces of the first rib portion 111 , the surface facing the second molding surface 120 is defined as the top surface of the first rib portion 111 . That is, of the surfaces of the first rib portion 111, the surface that comes into contact with the material B during hot press molding is defined as the "top surface”. As shown in FIG. 5B , the width W 111P of the top surface 111P in the cross section perpendicular to the extending direction of the first rib portion 111 is defined as the width of the first rib portion 111 .
- the width W 111P of the top surface 111P corresponds to the length of the top surface 111P in the direction (W direction in FIG. 5B) perpendicular to the extending direction of the first rib portion 111 and the normal direction of the top surface 111P.
- the height of the first rib portion 111 is defined as follows. 5B, the height H 111P from the top surface 111P of the first rib portion 111 to the groove bottom 112P of the first groove portion 112 is defined as the height of the first rib portion 111. As shown in FIG. In other words, the length from the top surface 111P of the first rib portion 111 to the groove bottom 112P of the first groove portion 112 in the normal direction (V direction in FIG. Define height H 111P .
- the width of the first groove portion 112 is defined as follows. As shown in FIG. 5B, in a cross section perpendicular to the extending direction of the first rib portion 111, the distance between the endpoint of one top surface 111P of the adjacent first rib portions 111 and the endpoint of the other top surface 111P of the adjacent first rib portions 111 The width W 112P of the gap is defined as the width of the first groove portion 112 .
- the width of the second rib portion 121 is defined as follows. Of the surfaces of the second rib portion 121 , the surface facing the first molding surface 110 is defined as the top surface of the second rib portion 121 . That is, of the surfaces of the second rib portion 121, the surface that comes into contact with the material B during hot press molding is defined as the "top surface”. As shown in FIG. 5B, the width W121P of the top surface 121P in the cross section perpendicular to the extending direction of the second rib portion 121 is defined as the width of the second rib portion 121. As shown in FIG.
- the width W121P of the top surface 121P corresponds to the length of the top surface 121P in the direction perpendicular to the extending direction of the second rib portion 121 and the normal direction of the top surface 121P (W direction in FIG. 5B).
- the height of the second rib portion 121 is defined as follows. 5B, the height H121P from the top surface 121P of the second rib portion 121 to the groove bottom 122P of the second groove portion 122 is defined as the height of the second rib portion 121. As shown in FIG. In other words, the length from the top surface 121P of the second rib portion 121 to the groove bottom 122P of the second groove portion 122 in the normal direction of the top surface 121P (in FIG. Define height.
- the width of the second groove portion 122 is defined as follows. As shown in FIG. 5B, in a cross section perpendicular to the extending direction of the second rib portion 121, the distance between the end point of one top surface 121P of the adjacent second rib portions 121 and the end point of the other top surface 121P The width W 122P of the gap is defined as the width of the second groove portion 122 .
- the shape of the first rib portion 111 or the second rib portion 121 in a cross section perpendicular to the extending direction may be rectangular as shown in FIGS. 5A and 5B, or may be rectangular as shown in FIG. Alternatively, it may be trapezoidal in shape, the width of which narrows toward the top surface 111P or 121P.
- the corners of the top surface 111P or 121P are chamfered, or the base of the first rib portion 111 or the second rib portion 121 is chamfered. It may have been.
- the corners of the top surface 111P or 121P may be rounded (that is, filleted), or the base of the first rib portion 111 or the second rib portion 121 may be rounded (that is, filledeted). can be used).
- the width of the top surface (111P or 121P) is the width of the portion of the top surface (111P and 121P) that is not chamfered or filleted.
- the mold 10 of this embodiment is a mold for hot press molding.
- the temperature of material B is A c 3 point or higher, which is higher than warm press molding. Therefore, the material B for hot press molding has a lower hardness and excellent workability than the material for warm press molding. Therefore, the surface pressure applied to the material B during hot press-forming is lower than that during warm press-forming. Therefore, even if the width of the first rib portion 111 is 50% or less of the width of the first groove portion 112, the surface of the material B is less likely to be scratched.
- the width of the second rib portion 121 is 10% or more of the width of the second groove portion 122, excessive reduction in the cooling rate of the material B is suppressed. can. Therefore, the impact absorption capacity of the hot press-formed product is improved.
- the cooling rate of the material B can be moderately slowed down. Therefore, it becomes easier to adjust the cooling stop temperature (that is, the temperature of the material B when the mold 10 is separated from the material B) during hot press molding.
- the cooling stop temperature is adjusted to a temperature above the Ms point, the cooling stop temperature is adjusted between the Mf point and the Ms point, or the Ms point is adjusted to 500 ° C. easier.
- the width of the second rib portion 121 is 10 to 50% of the width of the second groove portion 122 .
- a preferable upper limit of the ratio of the width of the second rib portion 121 to the width of the second groove portion 122 is 45%, more preferably 40%, and still more preferably 35%.
- a more preferable lower limit of the ratio of the width of the second rib portion 121 to the width of the second groove portion 122 is 12%, more preferably 14%.
- the surface of the material B is scratch resistant.
- the width of the first rib portion 111 is 1.0 to 8.0 mm, and the height of the first rib portion 111 is 0.2 to 5.0 mm.
- the width of the second rib portion 121 is 1.0 to 8.0 mm, and the height of the second rib portion 121 is 0.2 to 5.0 mm.
- the height of the first rib portion 111 corresponds to the depth of the first groove portion 112 .
- the height of the second rib portion 121 corresponds to the depth of the second groove portion 122 .
- the width of the first rib portion 111 or the width of the second rib portion 121 is 8.0 mm or less, the temperature variation in the width direction of the first rib portion 111 or the width direction of the second rib portion 121 in the material B is reduced. be able to. Therefore, it is possible to reduce variations in the cooling rate caused by variations in the temperature of the material B during hot press molding.
- the width of the first rib portion 111 or the width of the second rib portion 121 is set to 1.0 mm or more, the first rib portion 111 or the second rib portion 121 is less likely to break during hot press molding. and increase productivity. Therefore, the preferred width of the first rib portion 111 is 1.0 to 8.0 mm. A preferable width of the second rib portion 121 is 1.0 to 8.0 mm.
- a more preferable lower limit of the width of the first rib portion 111 is 1.8 mm, more preferably 2.0 mm.
- a more preferable lower limit of the width of the second rib portion 121 is 1.8 mm, more preferably 2.0 mm. In this case, the first rib portion 111 and the second rib portion 121 are even less likely to break. In addition, since the dimensional accuracy of the first rib portion 111 and the second rib portion 121 is relaxed, processing becomes easier.
- the height of the first rib portion 111 or the height of the second rib portion 121 is set to 0.2 mm or more, the occurrence of heat removal from the material B in the first groove portion 112 or the second groove portion 122 can be suppressed.
- the height of the first rib portion 111 or the height of the second rib portion 121 is set to 5.0 mm or less, the first rib portion 111 or the second rib portion 121 is Less likely to break, higher productivity. Therefore, the preferred height of the first rib portion 111 is 0.2 to 5.0 mm.
- a preferred height of the second rib portion 122 is 0.2 to 5.0 mm.
- the width or height of the first rib portion 111 or the second rib portion 121 is adjusted as described above in at least a part of the first slow cooling region 113 and the second slow cooling region 123, , the above-mentioned preferable effect can be obtained in the above-mentioned at least part of the region. Therefore, in the present embodiment, if the width or height of the first rib portion 111 or the second rib portion 121 is adjusted as described above in at least a part of the first slow cooling region 113 and the second slow cooling region 123, good.
- the width of the first rib portion 111 is 1.0 to 8.0 mm and the height is 0.2 to 5.0 mm over the entire first slow cooling region 113, and the second slow cooling region 123 , the width of the second rib portion 121 is 1.0 to 8.0 mm and the height is 0.2 to 5.0 mm.
- the width of the first rib portion 111 is 1.0 to 4.0 mm and 10 to 30% of the width of the first groove portion 112.
- the width of the second rib portion 121 is 1.0 to 4.0 mm and 10 to 30% of the width of the second groove portion 122. be.
- the cooling rate of material B can be further reduced. Therefore, it is easy to adjust the cooling stop temperature to a desired temperature. Furthermore, the temperature variation of the material B during hot press molding can be reduced.
- the first rib portion 111 and the second rib portion 121 extend in the same direction
- the first groove portion 112 and the second groove portion 122 extend in the same direction
- the width of the first rib portion 111 is 10 to 50% of the width of the first groove portion 112
- the width of the second rib portion 121 is 10 to 50% of the width of the second groove portion 122
- the first rib portion 111 and the second rib portion 121 is 1.0 to 8.0 mm
- the height of the first rib portion 111 and the second rib portion 121 is 0.2 to 5.0 mm.
- Fn1 defined by formula (1) is preferably 14 or less.
- Fn1 Wr0.9 / P00.8 +0.05Hr (1)
- Wr is the width (mm) of the first rib portion 111 and the second rib portion 121 .
- P0 Wr/Ws, where Ws is the width (mm) of the first groove 112 and the second groove 122 .
- Hr is the height (mm) of the first rib portion 111 and the second rib portion 121 .
- FIG. 8 is a diagram showing the relationship between Fn1 and the temperature variation ⁇ T (°C) in the first slow cooling region 113 and the second slow cooling region 123.
- FIG. FIG. 8 shows results obtained by the following two-dimensional heat transfer simulation. Specifically, the temperature distribution of the material B during hot press molding and the change over time of the temperature distribution were simulated by the finite difference method assuming the heat conduction model shown in FIG.
- FIG. 9 is a widthwise cross-sectional view of the first rib portion 111 and the second rib portion 121 in the first slow cooling region 113 and the second slow cooling region 123 .
- the material B was divided into a plurality of elements E each having an element width D0 of 1 mm, a thickness D1 of the material B (assumed to be 1.4 mm), and a unit length in the L direction.
- the balance Q (W/m 2 ) of the amount of heat per unit time (1 second) due to heat conduction and heat transfer in the i-th (i is a natural number) element E is shown by the following formula.
- the first rib portion 111 and the second rib portion 121 extend in the same direction, and the first groove portion 112 and the second groove portion 122 extend in the same direction.
- the width of the first rib portion 111 is the same as the width of the second rib portion 121 and the height of the first rib portion 111 is the same as the height of the second rib portion 121 .
- the width of the first groove portion 112 is the same as the width of the second groove portion 122 .
- the entire top surface of the first rib portion 111 overlaps the entire top surface of the second rib portion 121 during hot press molding.
- the cross-sectional shape perpendicular to the extending direction of the rib portions (111 and 121) was rectangular.
- the temperature Tbi of element E at time 0 (second) was set to 622°C. Furthermore, it is assumed that the element E is in contact with the first rib portion 111 and the second rib portion 121 in sections of 500 to 1000 mm on the right and left sides of FIG. ), and as a boundary condition, the heat conduction in the material B in the element E at the points of 1000 mm on the right and left sides of FIG. 9 is assumed to be adiabatic. Then, the temperature distribution of the material B and its change over time were simulated by performing sequential calculations for calculating the temperature change ⁇ Tb of the element E at intervals of 0.01 second.
- the difference Tbimax ⁇ Tbimin was defined as the temperature variation ⁇ T (° C.) of the material B and obtained.
- FIG. 8 was created using the obtained ⁇ T.
- the preferred upper limit of Fn1 is 14, more preferably 10. If Fn1 is 14 or less, for example, the temperature variation ⁇ T of material B is 110° C. or less. Also, if Fn1 is 10 or less, for example, the temperature variation ⁇ T of the material B is 40° C. or less.
- the first rib portion 111 and the second rib portion 121 extend in the same direction, the first groove portion 112 and the second groove portion 122 extend in the same direction, and the width of the first rib portion 111 is 10 to 50% of the width of the first groove portion 112, the width of the second rib portion 121 is 10 to 50% of the width of the second groove portion 122, and the width of the first rib portion 111 and the second rib portion 121 is Assume that the width is 1.0 to 8.0 mm and the height of the first rib portion 111 and the second rib portion 121 is 0.2 to 5.0 mm.
- Fn2 defined by formula (2) is preferably 30 or more.
- Ws is the width (mm) of the first groove portion 112 and the second groove portion 122 .
- Wr is the width (mm) of the first rib portion 111 and the second rib portion 121 .
- Hr is the height (mm) of the first rib portion 111 and the second rib portion 121 .
- FIG. 10 is a diagram showing the relationship between Fn2 and the cooling rate V (°C/sec) of material B during hot press molding.
- FIG. 10 was obtained by the above two-dimensional heat transfer simulation using the heat transfer model shown in FIG.
- the cooling rate V was obtained by averaging temperature changes of the element E per unit time from time 0 to the time when the temperature of the element E reached 400°C.
- the element E used for calculating the cooling rate is an element whose temperature Tbi indicates Tbimax.
- the cooling rate V of material B rapidly decreases, and thereafter the rate of decrease in cooling rate V becomes moderate. Therefore, the preferred lower limit for Fn2 is 30, more preferably 45, and even more preferably 90. If Fn2 is 30 or more, for example, the cooling rate V of material B is 80° C./second or less. Therefore, during hot press molding, it becomes easier to adjust the cooling stop temperature (that is, the temperature of the material B when the mold 10 is separated from the material B) to a desired temperature. If Fn2 is 45 or more, for example, the cooling rate of material B is 70° C./second or less. Therefore, it becomes easier to adjust the cooling stop temperature to a desired temperature. If Fn2 is 90 or more, for example, the cooling rate V of material B is 50° C./second or less. Therefore, it becomes easier to adjust the cooling stop temperature to a desired temperature.
- Fn1 is more preferably 14 or less and Fn2 is 30 or more.
- the temperature variation ⁇ T of the material B can be further suppressed, and the cooling stop temperature can be easily adjusted to a desired temperature.
- the first rib portion 111 and the second rib portion 121 extend in the same direction, the first groove portion 112 and the second groove portion 122 extend in the same direction, and the first rib
- the width of the portion 111 is 1.0 to 4.0 mm and 10 to 30% of the width of the first groove portion 112, and the width of the second rib portion 121 is 1.0 to 4.0 mm. and 10 to 30% of the width of the second groove portion 122, Fn1 is 14 or less, and/or Fn2 is 30 or more.
- the cooling rate of material B can be further reduced. Therefore, it is easy to adjust the cooling stop temperature to a desired temperature. Furthermore, the temperature variation of the material B during hot press molding can be reduced.
- the mold 10 according to this embodiment is not limited to the configuration described above.
- mold 10 is not limited to the shape shown in FIG.
- the first molding surface 110 and the second molding surface 120 of the mold 10 may be curved in the longitudinal direction.
- the cross-sectional shape perpendicular to the longitudinal direction (L direction) of the first molding surface 110 of the upper mold 11 of the mold 10 is not limited to a concave shape.
- the cross-sectional shape perpendicular to the longitudinal direction (L direction) of the second molding surface 120 of the lower mold 12 is not limited to a convex shape.
- the shapes of the first molding surface 110 and the second molding surface 120 are not particularly limited.
- the arrangement of the first slow cooling region 113 on the first molding surface 110 is not particularly limited.
- the arrangement of the second slow cooling region 123 on the second molding surface 120 is not particularly limited. It is sufficient that the first molding surface 110 includes the first slow cooling region 113 and the second molding surface 120 includes the second slow cooling region 123 .
- the first slow cooling region 113 and the second slow cooling region 123 are not limited to the form shown in FIG.
- FIG. 11 is a perspective view showing another example different from FIG. 2 of the mold 10 according to this embodiment.
- the first slow cooling region 113 may be arranged on the entire bottom surface of the groove of the concave portion of the first molding surface 110 of the upper mold 11 of the mold 10 .
- a second slow cooling region 123 may be arranged on the entire upper surface of the convex portion of the second molding surface 120 of the lower mold 12 of the mold 10 .
- FIG. 12 is a perspective view showing another example of the mold 10 according to this embodiment, which is different from FIGS. 2 and 11.
- a first slow cooling region 113 may be arranged on a part of the side surface of the concave portion of the first molding surface 110 of the upper mold 11 of the mold 10 .
- a second slow cooling region 123 may be arranged on a part of the side surface of the convex portion of the second molding surface 120 of the lower mold 12 of the mold 10 .
- FIG. 13 is a perspective view showing another example different from FIGS. 2, 11 and 12 of the mold 10 according to this embodiment. 2, 11 and 12, the first molding surface 110 includes a first slow cooling zone 113 and a first quenching zone 114.
- the second forming surface 120 includes a second slow cooling region 123 and a second rapid cooling region 124 .
- the entire first molding surface 110 may be the first slow cooling region 113 .
- the second molding surface 120 as a whole may be the second slow cooling region 123 .
- the first molding surface 110 includes the first slow cooling region 113 and the second molding surface 120 includes the second slow cooling region 123
- the first slow cooling region 113 in the first molding surface 110 and the position of the second slow cooling region 123 in the second molding surface 120 are not particularly limited.
- the upper mold 11 and the lower mold 12 are in contact with the material B and are pressing the material B during hot press molding, at least part of the first slow cooling area 113 is replaced by the second slow cooling area 123 and at least a portion of the are arranged opposite each other.
- the first slow cooling region 113 can also be defined as a part of the region in which the first rib portion 111 and the first groove portion 112 are formed.
- the second slow cooling region 123 can also be defined as a partial region of the region where the second rib portion 121 and the second groove portion 122 are formed.
- the width of the first rib portion 111 is narrower than the width of the first groove portion 112 in at least a partial region of the first molding surface 110, and the width of the second molding surface 120 is at least partially wide.
- the width of the second rib portion 121 is narrower than the width of the second groove portion 122 .
- the extending direction of the first rib portion 111 and the extending direction of the second rib portion 121 are not particularly limited.
- the first rib portion 111 and the second rib portion 121 do not have to extend in the L direction shown in FIGS. 5A and 6 .
- FIG. 14 is another example different from FIG. 5A among schematic diagrams in which the region 100 in FIG. 3 is enlarged.
- 15 is a cross-sectional view taken along the line segment XV--XV of FIG. 14.
- the first rib portion 111, the first groove portion 112, the second rib portion 121, and the second groove portion 122 all extend in the W direction, and the L lined up in the direction
- the width of the first rib portion 111, the width of the first groove portion 112, the width of the second rib portion 121, and the width of the second groove portion 122 all mean the width of the mold 10 in the L direction.
- the upper mold 11 moves in the V direction together with the slide 3.
- the material B is hot press-molded by the first molding surface 110 of the upper mold 11 and the second molding surface 120 of the lower mold 12 .
- the metal flow of the material B proceeds in the W direction by hot press molding. That is, in the region 100, the material B slides in the W direction with respect to the first molding surface 110 and the second molding surface 120. As shown in FIG.
- the material B is the first rib.
- the material B is less likely to receive frictional resistance from the portion 111 and/or the second rib portion 121 and easily slides on the first rib portion 111 and/or the second rib portion 121 . Therefore, formation of flaws on the surface of the material B can be suppressed.
- first rib portion 111, the first groove portion 112, the second rib portion 121, and the second groove portion 122 extend in the sliding direction of the material B during the hot press forming process. In this case, it is possible to suppress the formation of flaws on the surface of the material B during the hot press forming process.
- FIG. 16 is another example different from FIGS. 5A and 14 in a schematic diagram in which the region 100 in FIG. 3 is enlarged.
- FIG. 17 is a schematic diagram showing only the rib portion when the region 100 of FIG. 16 is viewed from the normal direction of the first slow cooling region 113 .
- FIGS. 5A and 6 are schematic diagrams showing only the rib portion when the region 100 of FIG. 16 is viewed from the normal direction of the first slow cooling region 113 .
- first rib portion 111 and the second rib portion 121 may at least partially overlap each other.
- FIG. 18 is another example different from FIGS. 5A, 14, and 16 in the enlarged schematic diagram of the region 100 in FIG.
- FIG. 19 is a schematic diagram showing only the rib portion when viewing the region 100 of FIG. 18 from the normal direction of the first slow cooling region.
- the plurality of first grooves 112 and the plurality of first ribs 111 both extend in the L direction, and the plurality of second grooves 122 and the plurality of second ribs 121 may extend in the W direction.
- first rib portion 111 and second rib portion 121 at least partially overlap when mold 10 is closed.
- the first slow cooling region 113 and the second slow cooling region 123 of the present embodiment preferably do not have supply ports for supplying the cooling medium to the surfaces of the first slow cooling region 113 and the second slow cooling region 123. preferable. If the first slow cooling region 113 and the second slow cooling region 123 have supply ports, the air remaining in the pipes inside the mold 10 (upper mold 11, lower mold 12) leading to the supply ports Excessive heat removal from the material B is facilitated in the portions of the first slow-cooling region 113 and the second slow-cooling region 123 that have the supply port. Therefore, the temperature variation of the material B may be promoted.
- the upper mold 11 and the lower mold 12 may have cooling passages through which a cooling medium passes. In this case, the temperatures of the upper mold 11 and the lower mold 12 during hot press molding can be kept sufficiently low.
- a method for manufacturing a hot press-formed product by hot press-forming using the mold 10 will be described.
- a method for manufacturing a hot press-formed product according to the present embodiment includes the following steps. ⁇ Preparation process ⁇ Heating process ⁇ Hot press molding process ⁇ Mold releasing process Each process will be described below.
- a material B having a desired chemical composition is prepared.
- the material B is not particularly limited.
- Material B is, for example, a steel plate.
- the type of steel plate is not particularly limited.
- the material B may be, for example, a steel plate subjected to surface treatment such as plating, or may be a steel plate not subjected to surface treatment such as plating (so-called bare material).
- the plating treatment may be a hot dip galvanizing treatment, an alloyed hot dip galvanizing treatment, or an aluminum plating treatment.
- the chemical composition of the base material steel plate of material B is not particularly limited as described above.
- the base material steel plate of material B for example, in mass%, C: 0.10 to 0.60%, Si: 0 to 5.0%, Mn: 0 to 5.0%, P: 0.100% or less, S: 0.100% or less, N: 0.100% or less, O: 0.100% or less, Al: 0 to 1.0%, Cr: 0 to 3.0%, Mo: 0 to 5.0% , V: 0-2.0%, Nb: 0-1.0%, Ti: 0-1.0%, B: 0-1.0%, Ca: 0-1.0%, Mg: 0- 1.0%, Zr: 0-1.0%, Rare earth elements: 0-1.0%, Co: 0-5.0%, W: 0-5.0%, Ni: 0-3.0% , Cu: 0-3.0%, and the balance being Fe and impurities.
- the impurities are elements that are mixed from ore, scrap, or the manufacturing environment as raw materials when industrially manufacturing steel materials, and have an
- the thickness of material B is not particularly limited, but is selected according to the characteristics of the hot press-formed product to be obtained.
- the thickness of the material B is, for example, 0.6-3.2 mm.
- the mechanical properties of material B are also not particularly limited. The mechanical properties of the material B are appropriately selected according to the properties of the hot press-formed product to be obtained.
- the tensile strength of material B may be, for example, 400 MPa or more.
- the method of preparing material B is not particularly limited.
- the raw material B may be manufactured from molten steel having the chemical composition described above by a known manufacturing method. It may be prepared by purchasing material B manufactured by a third party.
- the prepared material B is heated to a temperature of Ac3 or higher. If the heating temperature is less than the Ac3 point, the material B will not become an austenite single phase. In this case, when the material B is cooled in the hot press forming process, the hard phase (martensite and/or bainite) is formed in the area sandwiched between the first quenched region 114 and the second quenched region 124 in the material B. Insufficient formation. Therefore, sufficient strength may not be obtained. If the heating temperature is A c3 point or more, the material B before the hot press forming process becomes austenite single phase.
- the heating temperature is preferably less than 950°C. In this case, the heating time of the material B can be shortened, and the productivity can be improved. Furthermore, since the fuel and power required for heating can be reduced, manufacturing costs can be suppressed.
- the method of heating material B is not particularly limited.
- the material B may be heated using a heating furnace such as an electric furnace, gas furnace, far-infrared furnace, or near-infrared furnace.
- the material B may be heated using an electric heating device, a high-frequency induction heating device, or the like.
- the method for heating the material B is not limited, and a known heating method can be appropriately selected.
- Hot press molding process In the hot press-molding step, the material B heated to the Ac 3 point or higher is hot press-molded using the above-described mold 10 .
- the material B heated in the heating process is placed on the second molding surface 120 of the lower mold 12 .
- the upper mold 11 is brought relatively closer to the lower mold 12, and the mold 10 is closed.
- the material B contacts the first molding surface 110 of the upper mold 11 and the second molding surface 120 of the lower mold 12 .
- the material B is sandwiched between the first molding surface 110 of the upper mold 11 and the second molding surface 120 of the lower mold 12 .
- Hot press molding is performed on the material B by the upper mold 11 and the lower mold 12 .
- the material B is not cooled using a cooling medium during hot press-forming. Instead, heat is removed from the material B by the mold 10 that contacts the material B during hot press molding.
- the mold 10 When the mold 10 is closed, the first rib portion 111 of the first molding surface 110 of the upper mold 11 and the material B are in contact with each other in the first slow cooling region 113 .
- the second rib portion 121 of the second molding surface 120 of the lower mold 12 and the material B are in contact with each other in the second slow cooling region 123 .
- the temperature of the upper mold 11 and the lower mold 12 is sufficiently lower than that of the material B. Therefore, the heat of the material B is removed by the first rib portion 111 and the second rib portion 121 .
- the temperature of the upper mold 11 and the lower mold 12 is, for example, room temperature (20 ⁇ 15°C) to 200°C.
- the hot press-formed material B is released from the mold 10 to produce a hot press-formed product.
- the temperature of the material B (hot press-formed product) when released from the mold 10 is defined as the cooling stop temperature.
- the cooling stop temperature is between the Mf point and Ms point of the hot press-formed product, or between the Ms point and above and 500 ° C.
- the microstructure of the hot press-formed product is a structure consisting of a hard phase, Alternatively, a structure consisting of a hard phase and retained austenite is obtained. In this case, the resulting hot press-formed product has excellent impact absorption ability.
- the temperature of the region sandwiched between the first slow cooling region 113 and the second slow cooling region 123 of the material B is Mf
- the material B is released from the mold 10 when the temperature is between the point and the Ms point, or when the temperature is above the Ms point and between 500°C.
- the Ms point and Mf point of material B differ depending on the chemical composition of material B. Therefore, when attempting to obtain a structure consisting of a hard phase or a structure consisting of a hard phase and retained austenite in the material B, the preferred cooling stop temperature differs depending on the chemical composition of the material B.
- the first rib portion 111, the first groove portion 112, the second Based on the width and height of the two rib portions 121 and the second groove portions 122 and the chemical composition of the material B, a heat transfer simulation was performed to determine the first slow cooling region 113 and the second slow cooling region of the material B.
- a hot press-formed product having a structure consisting of a hard phase or a structure consisting of a hard phase and retained austenite can be hot-pressed according to the chemical composition of the material B. It can be manufactured by molding.
- the method for manufacturing a hot press-formed product according to the present embodiment may further include manufacturing steps other than those described above.
- a heating and holding step in a temperature range of 500° C. or less may be performed after the mold release step.
- the hot press-formed product after the mold release process is heated and held in a temperature range of 500°C or less.
- the hot press-formed product produced by releasing from the mold 10 is held at a heating temperature of 100 to 500.degree.
- the heat hold can distribute carbon from the hard phases to the retained austenite in the microstructure of the hot pressed part.
- the formation of retained austenite is accelerated due to the enrichment of carbon in the retained austenite.
- the proportion of retained austenite increases in the hot press-formed product.
- the retained austenite transforms into martensite during impact deformation, improving the ductility of the hot press-formed product (so-called TRIP (transformation induced plasticity) effect).
- TRIP transformation induced plasticity
- the preferred upper limit of the heating and holding temperature is 400°C.
- the heating and holding temperature is preferably -209° C. or higher at the Ms point. In this case, the impact absorption capacity of the hot press-formed product is stabilized and further enhanced. Therefore, when the Ms point -209°C exceeds 100°C, the preferable lower limit of the heating and holding temperature is the Ms point -209°C.
- the heating holding time is not particularly limited.
- the holding time at the heating and holding temperature is preferably 5 seconds to 30 minutes (1800 seconds), for example.
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Abstract
Description
金型は、上型と、下型とを備える。上型は、第1成形面を有する。下型は、第2成形面を有する。第2成形面は、熱間プレス成形時において、第1成形面と対向して配置され、第1成形面とともに、素材を熱間プレス成形する。
第1成形面は、第1緩冷却領域を含む。第1緩冷却領域は、複数の第1リブ部と複数の第1溝部とを有する。複数の第1リブ部は、第1リブ部の幅方向に配列される。複数の第1溝部は、第1溝部の幅方向に配列される。第1リブ部は、隣り合う第1溝部の間に形成されている。第1リブ部の幅は、第1溝部の幅よりも狭い。
第2成形面は、第2緩冷却領域を含む。第2緩冷却領域は、複数の第2リブ部と複数の第2溝部とを有する。複数の第2リブ部は、第2リブ部の幅方向に配列される。複数の第2溝部は、第2溝部の幅方向に配列される。第2リブ部は、隣り合う第2溝部の間に形成されている。第2リブ部の幅は、第2溝部の幅よりも狭い。
熱間プレス成形時において、第1緩冷却領域及び第2緩冷却領域を、第1緩冷却領域の法線方向から見たとき、第1リブ部と第2リブ部とは、少なくとも一部が重複している。 A mold according to the present disclosure is a mold for performing hot press molding on a material.
The mold includes an upper mold and a lower mold. The upper mold has a first molding surface. The lower mold has a second molding surface. The second molding surface is arranged to face the first molding surface during hot press molding, and together with the first molding surface hot press mold the material.
The first molding surface includes a first slow cooling region. The first slow cooling region has a plurality of first ribs and a plurality of first grooves. The plurality of first rib portions are arranged in the width direction of the first rib portion. The plurality of first grooves are arranged in the width direction of the first grooves. The first rib is formed between adjacent first grooves. The width of the first rib portion is narrower than the width of the first groove portion.
The second molding surface includes a second slow cooling region. The second slow cooling region has a plurality of second rib portions and a plurality of second groove portions. The plurality of second rib portions are arranged in the width direction of the second rib portions. The plurality of second grooves are arranged in the width direction of the second grooves. The second rib is formed between adjacent second grooves. The width of the second rib portion is narrower than the width of the second groove portion.
During hot press forming, when the first slow cooling region and the second slow cooling region are viewed from the normal direction of the first slow cooling region, at least a part of the first rib portion and the second rib portion Duplicate.
素材に対して熱間プレス成形を実施するための金型であって、
第1成形面を有する上型と、
熱間プレス成形時において、前記第1成形面と対向して配置され、前記第1成形面とともに前記素材を熱間プレス成形する第2成形面を有する下型とを備え、
前記第1成形面は、
複数の第1リブ部と複数の第1溝部とを有する第1緩冷却領域を含み、
複数の前記第1リブ部は、前記第1リブ部の幅方向に配列され、
複数の前記第1溝部は、前記第1溝部の幅方向に配列され、
前記第1リブ部は、隣り合う前記第1溝部の間に形成されており、
前記第1リブ部の幅は、前記第1溝部の幅よりも狭く、
前記第2成形面は、
複数の第2リブ部と複数の第2溝部とを有する第2緩冷却領域を含み、
複数の前記第2リブ部は、前記第2リブ部の幅方向に配列され、
複数の前記第2溝部は、前記第2溝部の幅方向に配列され、
前記第2リブ部は、隣り合う前記第2溝部の間に形成されており、
前記第2リブ部の幅は、前記第2溝部の幅よりも狭く、
熱間プレス成形時において、前記第1緩冷却領域及び前記第2緩冷却領域を、前記第1緩冷却領域の法線方向から見たとき、
前記第1リブ部と前記第2リブ部とは、少なくとも一部が重複している、
金型。 [1]
A mold for performing hot press molding on a material,
an upper mold having a first molding surface;
a lower mold having a second molding surface that is arranged to face the first molding surface and hot press molds the material together with the first molding surface during hot press molding;
The first molding surface is
including a first slow cooling region having a plurality of first ribs and a plurality of first grooves;
The plurality of first rib portions are arranged in the width direction of the first rib portion,
The plurality of first grooves are arranged in the width direction of the first grooves,
The first rib portion is formed between the adjacent first groove portions,
The width of the first rib portion is narrower than the width of the first groove portion,
The second molding surface is
including a second slow cooling region having a plurality of second ribs and a plurality of second grooves;
The plurality of second rib portions are arranged in the width direction of the second rib portion,
The plurality of second grooves are arranged in the width direction of the second grooves,
The second rib portion is formed between the adjacent second groove portions,
The width of the second rib portion is narrower than the width of the second groove portion,
During hot press forming, when the first slow cooling region and the second slow cooling region are viewed from the normal direction of the first slow cooling region,
At least a portion of the first rib portion and the second rib portion overlap,
Mold.
[1]に記載の金型であって、
熱間プレス成形時において、前記第1緩冷却領域及び前記第2緩冷却領域を、前記第1緩冷却領域の法線方向から見たとき、
前記第1リブ部と前記第2リブ部とは、同じ方向に延びており、
前記第1溝部と前記第2溝部とは、同じ方向に延びている、
金型。 [2]
The mold according to [1],
During hot press forming, when the first slow cooling region and the second slow cooling region are viewed from the normal direction of the first slow cooling region,
The first rib portion and the second rib portion extend in the same direction,
The first groove and the second groove extend in the same direction,
Mold.
[1]又は[2]に記載の金型であって、
前記第1リブ部の幅は、前記第1溝部の幅の10~50%であり、
前記第2リブ部の幅は、前記第2溝部の幅の10~50%である、
金型。 [3]
The mold according to [1] or [2],
The width of the first rib portion is 10 to 50% of the width of the first groove portion,
The width of the second rib portion is 10 to 50% of the width of the second groove portion,
Mold.
[1]~[3]のいずれか1つに記載の金型であって、
前記第1緩冷却領域の少なくとも一部において、
前記第1リブ部の幅は、1.0~8.0mmであり、
前記第1リブ部の高さは、0.2~5.0mmであり、
前記第2緩冷却領域の少なくとも一部において、
前記第2リブ部の幅は、1.0~8.0mmであり、
前記第2リブ部の高さは、0.2~5.0mmである、
金型。 [4]
The mold according to any one of [1] to [3],
In at least part of the first slow cooling region,
The width of the first rib portion is 1.0 to 8.0 mm,
The height of the first rib portion is 0.2 to 5.0 mm,
In at least part of the second slow cooling region,
The width of the second rib portion is 1.0 to 8.0 mm,
The height of the second rib portion is 0.2 to 5.0 mm,
Mold.
[2]に記載の金型であって、
前記第1リブ部の幅は、前記第1溝部の幅の10~50%であり、
前記第2リブ部の幅は、前記第2溝部の幅の10~50%であり、
前記第1リブ部及び前記第2リブ部の各々の幅は1.0~8.0mmであり、
前記第1リブ部及び前記第2リブ部の各々の高さは0.2~5.0mmであり、
式(1)で定義されるFn1が14以下である、
金型。
Fn1=Wr0.9/P00.8+0.05Hr (1)
ここで、式(1)中のWrは前記第1リブ部及び前記第2リブ部の幅(mm)であり、P0=Wr/Wsであり、Wsは前記第1溝部及び前記第2溝部の幅(mm)であり、Hrは前記第1リブ部及び前記第2リブ部の高さ(mm)である。 [5]
The mold according to [2],
The width of the first rib portion is 10 to 50% of the width of the first groove portion,
The width of the second rib portion is 10 to 50% of the width of the second groove portion,
The width of each of the first rib portion and the second rib portion is 1.0 to 8.0 mm,
Each height of the first rib portion and the second rib portion is 0.2 to 5.0 mm,
Fn1 defined by formula (1) is 14 or less,
Mold.
Fn1= Wr0.9 / P00.8 +0.05Hr (1)
Here, Wr in the formula (1) is the width (mm) of the first rib portion and the second rib portion, P0 = Wr/Ws, and Ws is the width of the first groove portion and the second groove portion. is the width (mm), and Hr is the height (mm) of the first rib portion and the second rib portion.
[2]又は[5]に記載の金型であって、
前記第1リブ部の幅は、前記第1溝部の幅の10~50%であり、
前記第2リブ部の幅は、前記第2溝部の幅の10~50%であり、
前記第1リブ部及び前記第2リブ部の各々の幅は1.0~8.0mmであり、
前記第1リブ部及び前記第2リブ部の各々の高さは0.2~5.0mmであり、
式(2)で定義されるFn2が30以上である、
金型。
Fn2=Ws2×Hr0.4/Wr (2)
ここで、式(2)中のWsは前記第1溝部及び前記第2溝部の幅(mm)であり、Wrは前記第1リブ部及び前記第2リブ部の幅(mm)であり、Hrは前記第1リブ部及び前記第2リブ部の高さ(mm)である。 [6]
The mold according to [2] or [5],
The width of the first rib portion is 10 to 50% of the width of the first groove portion,
The width of the second rib portion is 10 to 50% of the width of the second groove portion,
The width of each of the first rib portion and the second rib portion is 1.0 to 8.0 mm,
Each height of the first rib portion and the second rib portion is 0.2 to 5.0 mm,
Fn2 defined by formula (2) is 30 or more,
Mold.
Fn2=Ws2* Hr0.4 /Wr ( 2 )
Here, Ws in the formula (2) is the width (mm) of the first groove portion and the second groove portion, Wr is the width (mm) of the first rib portion and the second rib portion, and Hr is the height (mm) of the first rib portion and the second rib portion.
[4]~[6]のいずれか1項に記載の金型であって、
前記第1緩冷却領域の少なくとも一部において、
前記第1リブ部の幅は、1.0~4.0mmであり、かつ、前記第1溝部の幅の10~30%であり、
前記第2緩冷却領域の少なくとも一部において、
前記第2リブ部の幅は、1.0~4.0mmであり、かつ、前記第2溝部の幅の10~30%である、
金型。 [7]
The mold according to any one of [4] to [6],
In at least part of the first slow cooling region,
The width of the first rib portion is 1.0 to 4.0 mm and 10 to 30% of the width of the first groove portion,
In at least part of the second slow cooling region,
The width of the second rib portion is 1.0 to 4.0 mm, and 10 to 30% of the width of the second groove portion.
Mold.
熱間プレス成形品の製造方法であって、
素材を準備する工程と、
前記準備された素材をAc3点以上の温度に加熱する工程と、
加熱された前記素材に対して、[1]~[7]のいずれか1項に記載の金型により熱間プレス成形を実施する工程と、
熱間プレス成形された前記素材を、前記金型から離型して、熱間プレス成形品を製造する工程とを備える、
熱間プレス成形品の製造方法。 [8]
A method for manufacturing a hot press-formed product,
a process of preparing materials;
heating the prepared material to a temperature of A c 3 or higher;
A step of performing hot press molding on the heated material using the mold according to any one of [1] to [7];
A step of releasing the hot press-formed material from the mold to produce a hot press-formed product;
A method for producing a hot press-formed product.
[8]に記載の熱間プレス成形品の製造方法であってさらに、
前記金型から離型して製造された前記熱間プレス成形品を、100~500℃で保持する工程とを備える、
熱間プレス成形品の製造方法。 [9]
The method for producing a hot press-formed product according to [8], further comprising:
A step of holding the hot press-formed product produced by releasing from the mold at 100 to 500 ° C.
A method for producing a hot press-formed product.
図1は、熱間プレス成形用の熱間プレス装置1の一例を示す正面図である。図1を参照して、熱間プレス装置1は、本実施形態による金型10を除き、公知の熱間プレス装置と実質的に同じ構成を備える。熱間プレス装置1は、フレーム2と、スライド3と、ボルスタ4と、金型10(上型11及び下型12)とを備える。以降の説明において、熱間プレス装置1の鉛直方向(上下)方向をV方向、熱間プレス装置1の幅方向をW方向、V方向とW方向と垂直な方向をL方向ともいう。 [Configuration of hot press device 1]
FIG. 1 is a front view showing an example of a
図1中の金型10の構成について、さらに詳細に説明する。
図2は、図1中の金型10の斜視図である。図2を参照して、上型11は、第1成形面110を有する。第1成形面110は、上型11の下面に配置されている。図2では、第1成形面110は、W方向中央部に、L方向に延びる凹部を含む。 [Configuration of mold 10]
The configuration of the
FIG. 2 is a perspective view of the
第1成形面110は、斜線部で示す第1緩冷却領域113を含む。図2では、第1緩冷却領域113は、第1成形面110の一部に形成される。図2では、第1成形面110は、第1緩冷却領域113と、第1急冷領域114とを含む。
同様に、第2成形面120は、斜線部で示す第2緩冷却領域123を含む。図2では、第2緩冷却領域123は、第2成形面120の一部に形成される。図2では、第2成形面120は、第2緩冷却領域123と、第2急冷領域124とを含む。
熱間プレス成形時において、第1急冷領域114は、第2急冷領域124と対向する。第1急冷領域114と、第2急冷領域124とは、熱間プレス成形後の素材(熱間プレス成形品)に、高強度を有する高強度領域を形成する。
熱間プレス成形時において、第1緩冷却領域113は、第2緩冷却領域123と対向する。第1緩冷却領域113と、第2緩冷却領域123とは、熱間プレス成形後の素材(熱間プレス成形品)に、高強度領域よりも強度が低く、塑性変形しやすい衝撃緩衝領域を形成する。 [Configuration of
The
Similarly, the
During hot press forming, the first quench
During hot press forming, the first
[第1緩冷却領域113の構成]
図5Aは、図3中の第1成形面110の第1緩冷却領域113内の領域100の拡大図である。図5Aを参照して、上型11の第1成形面110の第1緩冷却領域113は、複数の第1リブ部111と、複数の第1溝部112とを有する。図6は、図3の領域100を上方向(第1緩冷却領域113及び第2緩冷却領域123の法線方向)から見た、領域100の模式図である。図5A及び図6を参照して、複数の第1リブ部111は、所定の方向に延在している。図5A及び図6では、一例として、複数の第1リブ部111は、L方向に延びている。ただし、複数の第1リブ部111の延在方向は、L方向に限定されない。 [Configuration of first molding surface 110]
[Configuration of first slow cooling region 113]
5A is an enlarged view of the
図7は、図4の第1成形面110の第1急冷領域114中の領域200の拡大図である。図7を参照して、上型11の第1成形面110の第1急冷領域114では、第1リブ部111及び第1溝部112は形成されていない。換言すれば、第1成形面110の第1急冷領域114は、滑らかな面である。そのため、熱間プレス成形時において、第1急冷領域114の略全体が、素材Bと接触する。そのため、第1急冷領域114では、第1緩冷却領域113と比較して、素材Bの冷却速度を速くすることができる。そのため、金型10を用いて熱間プレス成形が実施された場合、素材Bのうち、第1急冷領域114に接触した領域の焼入れの度合いを高めることができる。その結果、熱間プレス成形後の素材B(熱間プレス成形品)に、衝撃緩衝領域よりも強度の高い高強度領域を形成することができる。 [Configuration of first quenching region 114]
FIG. 7 is an enlarged view of
[第2緩冷却領域123の構成]
図5Aを参照して、下型12の第2成形面120の第2緩冷却領域123は、複数の第2リブ部121と、複数の第2溝部122とを有する。図5A及び図6を参照して、複数の第2リブ部121は、所定の方向に延在している。図5A及び図6では、複数の第2リブ部121は、L方向に延びている。ただし、複数の第2リブ部121の延在方向は、L方向に限定されない。 [Configuration of second molding surface 120]
[Configuration of the second slow cooling region 123]
Referring to FIG. 5A , second
図7を参照して、下型12の第2成形面120の第2急冷領域124では、第2リブ部121及び第2溝部122は形成されていない。つまり、第2成形面120の第2急冷領域124は、滑らかな面である。そのため、熱間プレス成形時において、第2急冷領域124の略全体が、素材Bと接触する。そのため、第2急冷領域124では、第2緩冷却領域123と比較して、素材Bの冷却速度を速くすることができる。そのため、金型10を用いて熱間プレス成形が実施された場合、素材Bのうち、第2急冷領域124に接触した領域の焼入れの度合いを高めることができる。その結果、熱間プレス成形後の素材B(熱間プレス成形品)に、衝撃緩衝領域よりも強度の高い高強度領域を形成することができる。 [Configuration of the second rapid cooling region 124]
Referring to FIG. 7 ,
金型10ではさらに、熱間プレス成形時において、第1成形面110の第1緩冷却領域113及び第2成形面120の第2緩冷却領域123を、第1緩冷却領域113の法線方向から見たとき、第1リブ部111と第2リブ部121とは、少なくとも一部が重複している。ここでいう、「熱間プレス成形時」とは、上型11の成形面110の略全体と、下型12の成形面120の略全体とが、素材Bと接触して素材Bに外力を付与している状態を意味し、金型10が閉じた状態であって、上型11が下死点で保持されつつ素材Bが金型10により冷却されている状態を意味する。 [Relationship between
Further, in the
以上のとおり、本実施形態の金型10では、第1緩冷却領域113の第1リブ部111の幅は第1溝部112の幅よりも狭い。さらに、第2緩冷却領域123の第2リブ部121の幅は第2溝部122の幅よりも狭い。そのため、金型10を用いて熱間プレス成形を実施した場合、第1緩冷却領域113及び第2緩冷却領域123で挟まれた素材Bの領域では、冷却速度が抑えられる。そのため、熱間プレス成形品内で、強度を抑えた衝撃緩衝領域と、衝撃緩衝領域よりも強度の高い高強度領域とを形成することができる。さらに、熱間プレス成形時に、第1緩冷却領域113及び第2緩冷却領域123を、第1緩冷却領域113の法線方向から見たとき、第1リブ部111と第2リブ部121とは、少なくとも一部が重複する。そのため、衝撃緩衝領域において、素材Bが波状に変形するのを抑制することができる。 [Features of mold 10]
As described above, in the
第1緩冷却領域113及び第2緩冷却領域123において、好ましくは、第1リブ部111と、第2リブ部121とは、同じ方向に延びている。さらに、第1溝部112と、第2溝部122とは、同じ方法に延びている。図5A及び図6では、第1リブ部111と、第2リブ部121とは、L方向に延びており、第1溝部112と、第2溝部122とは、L方向に延びている。 [Regarding a preferred form of the mold 10]
In the first
好ましくは、緩冷却領域113に形成された第1リブ部111の幅は、第1溝部112の幅の10~50%であり、緩冷却領域123に形成された第2リブ部121の幅は、第2溝部122の幅の10~50%である。 [Relationship between preferred
Preferably, the width of the
第1リブ部111の幅の第1溝部112の幅に対する比のさらに好ましい上限は45%であり、さらに好ましくは40%であり、さらに好ましくは35%である。
第1リブ部111の幅の第1溝部112の幅に対する比のさらに好ましい下限は12%であり、さらに好ましくは14%である。 Therefore, preferably, the width of the
More preferably, the upper limit of the ratio of the width of the
A more preferable lower limit of the ratio of the width of the
第2リブ部121の幅の第2溝部122の幅に対する比の好ましい上限は45%であり、さらに好ましくは40%であり、さらに好ましくは35%である。
第2リブ部121の幅の第2溝部122の幅に対する比のさらに好ましい下限は12%であり、さらに好ましくは14%である。 Therefore, the width of the
A preferable upper limit of the ratio of the width of the
A more preferable lower limit of the ratio of the width of the
好ましくは、第1緩冷却領域113の少なくとも一部において、第1リブ部111の幅は1.0~8.0mmであり、第1リブ部111の高さは0.2~5.0mmであり、第2緩冷却領域123の少なくとも一部において、第2リブ部121の幅は1.0~8.0mmであり、第2リブ部121の高さは0.2~5.0mmである。第1リブ部111の高さは、第1溝部112の深さに相当する。同様に、第2リブ部121の高さは、第2溝部122の深さに相当する。 [Preferred Width and Height of
Preferably, in at least part of the first
金型10において、第1リブ部111と第2リブ部121とが同じ方向に延びており、第1溝部112と第2溝部122とが同じ方向に延びており、第1リブ部111の幅は、第1溝部112の幅の10~50%であり、第2リブ部121の幅は、第2溝部122の幅の10~50%であり、第1リブ部111及び第2リブ部121の幅が1.0~8.0mmであり、第1リブ部111及び第2リブ部121の高さが0.2~5.0mmである場合を想定する。
この場合、好ましくは、式(1)で定義されるFn1が14以下である。
Fn1=Wr0.9/P00.8+0.05Hr (1)
ここで、Wrは第1リブ部111及び第2リブ部121の幅(mm)である。P0=Wr/Wsであり、Wsは第1溝部112及び第2溝部122の幅(mm)である。Hrは第1リブ部111及び第2リブ部121の高さ(mm)である。以下、Fn1について説明する。 [About Fn1]
In the
In this case, Fn1 defined by formula (1) is preferably 14 or less.
Fn1= Wr0.9 / P00.8 +0.05Hr (1)
Here, Wr is the width (mm) of the
この式の各項を、次の式で定義した。
(要素Eが第1リブ部111及び第2リブ部121に接触している場合)
Q1:素材Bとリブ部(111又は121)との接触熱伝達による要素Eの単位時間当たりの金型への熱量の移動(W/m2)
Q1=-h(Tr-Tbi)
熱伝達係数h=2000W/m2・K
金型温度Tr=100℃
Tbi:素材Bにおけるi番目の要素Eの温度
(要素Eが第1リブ部111及び第2リブ部121に接触していない場合)
Q1:溝部(112又は122)での空気を介した熱伝導による要素Eの単位時間当たりの熱量の金型への移動(W/m2)
Q1=-λa(Tr-Tbi)/Hr
λa:空気の熱伝導率=0.04W/m・K
Q2i:素材B内の熱伝導によるi-1番目の要素Eから単位時間当たりの隣接するi番目の要素Eへの熱量の移動(W/m2)
Q2i=-λb(Tbi-Tbi-1)/Δx
λb:素材Bの熱伝導率=50W/m・K
Tbi:i番目の要素E(素材B)の温度
Tbi-1:i番目の要素Eと隣接するi-1番目の要素Eの温度
Δx:隣接する要素E間の距離=1mm Q=(Q2i)-(Q2i+1)-2Q1
Each term of this formula is defined by the following formula.
(When the element E is in contact with the
Q1: Transfer of heat quantity to the mold per unit time of element E due to contact heat transfer between material B and rib (111 or 121) (W/m 2 )
Q1=-h(Tr-Tbi)
Heat transfer coefficient h = 2000 W/m 2 K
Mold temperature Tr = 100°C
Tbi: Temperature of i-th element E in material B (when element E is not in contact with
Q1: Transfer of the amount of heat per unit time from the element E to the mold due to heat conduction through the air in the groove (112 or 122) (W/m 2 )
Q1=-λa(Tr-Tbi)/Hr
λa: Thermal conductivity of air = 0.04 W/m K
Q2i: heat transfer from the i−1th element E to the adjacent ith element E per unit time due to heat conduction in the material B (W/m 2 )
Q2i=-λb(Tbi-Tbi-1)/Δx
λb: Thermal conductivity of material B = 50 W/m K
Tbi: temperature of i-th element E (material B) Tbi-1: temperature of i-1-th element E adjacent to i-th element E Δx: distance between adjacent elements E = 1 mm
ΔTb=Q/(c・ρ・D0・D1)
c:素材Bの比熱=0.435J/(g・K)
ρ:素材Bの密度=7.8×10^3(g/m3) By the way, the temperature change ΔTb (°C) of the element E per unit time associated with the heat balance Q is expressed by the following formula.
ΔTb=Q/(c・ρ・D0・D1)
c: Specific heat of material B = 0.435 J/(g K)
ρ: Density of material B = 7.8 × 10^3 (g/m 3 )
金型10において、第1リブ部111と第2リブ部121とが同じ方向に延びており、第1溝部112と第2溝部122とが同じ方向に延びており、第1リブ部111の幅は、第1溝部112の幅の10~50%であり、第2リブ部121の幅は、第2溝部122の幅の10~50%であり第1リブ部111及び第2リブ部121の幅が1.0~8.0mmであり、第1リブ部111及び第2リブ部121の高さが0.2~5.0mmである場合を想定する。
この場合、好ましくは、式(2)で定義されるFn2が30以上である。
Fn2=Ws2×Hr0.4/Wr (2)
ここで、Wsは第1溝部112及び第2溝部122の幅(mm)である。Wrは第1リブ部111及び第2リブ部121の幅(mm)である。Hrは第1リブ部111及び第2リブ部121の高さ(mm)である。 [About Fn2]
In the
In this case, Fn2 defined by formula (2) is preferably 30 or more.
Fn2=Ws2* Hr0.4 /Wr ( 2 )
Here, Ws is the width (mm) of the
[金型10の第1成形面110及び第2成形面120の形状について]
本実施形態による金型10は、上記構成に限定されない。例えば、金型10は図2に示す形状に限定されない。金型10の第1成形面110及び第2成形面120は長手方向に湾曲していてもよい。また、金型10の上型11の第1成形面110の長手方向(L方向)に垂直な断面形状は、凹形状に限定されない。下型12の第2成形面120の長手方向(L方向)に垂直な断面形状は、凸形状に限定されない。上型11の第1成形面110が、下型12の第2成形面120と嵌合すれば、第1成形面110及び第2成形面120の形状は特に限定されない。 [Another form of the
[Regarding the shape of the
The
また、第1成形面110の第1緩冷却領域113の配置は特に限定されない。同様に、第2成形面120の第2緩冷却領域123の配置は特に限定されない。第1成形面110が第1緩冷却領域113を含み、第2成形面120が第2緩冷却領域123を含んでいればよい。 [Arrangement of First
Also, the arrangement of the first
本実施形態において、第1リブ部111の延在方向、及び、第2リブ部121の延在方向は、特に限定されない。例えば、第1リブ部111及び第2リブ部121は、図5A及び図6に示されるL方向に延在していなくてもよい。図14は、図3の領域100を拡大した模式図のうち、図5Aとは異なる他の一例である。図15は図14の線分XV-XVでの断面図である。図14及び図15を参照して、本実施形態では、第1リブ部111、第1溝部112、第2リブ部121、及び、第2溝部122は、いずれもW方向に延在し、L方向に並んでいる。この場合、第1リブ部111の幅、第1溝部112の幅、第2リブ部121の幅、及び、第2溝部122の幅は、いずれも、金型10のL方向の幅を意味する。 [Regarding the extending direction of the
In the present embodiment, the extending direction of the
本実施形態において、第1リブ部111と第2リブ部121との配置は、図5A及び図6に示されるように、金型10が閉じた状態において、完全に重複していなくてもよい。図16は、図3の領域100を拡大した模式図のうち、図5A及び図14とは異なる他の一例である。図17は、図16の領域100を第1緩冷却領域113の法線方向から見て、リブ部のみを図示した模式図である。例えば、図16及び図17を参照して、金型10が閉じた状態において、第1リブ部111と第2リブ部121とが、平行に配置され、互いにずれた状態で重複していてもよい。このように、第1リブ部111と第2リブ部121とは、少なくとも一部が重複すればよい。 [Regarding the arrangement relationship between the
In this embodiment, the arrangement of the
本実施形態の第1緩冷却領域113及び第2緩冷却領域123は、冷却媒体を第1緩冷却領域113及び第2緩冷却領域123の表面に供給するための供給口を有さない方が好ましい。仮に、第1緩冷却領域113及び第2緩冷却領域123が供給口を有する場合、供給口に通じる金型10(上型11、下型12)内部の配管内に滞留している空気により、第1緩冷却領域113及び第2緩冷却領域123のうち供給口を有する部分で、素材Bが過剰に抜熱されやすくなる。そのため、素材Bの温度ばらつきが助長される可能性がある。 [Regarding the first
The first
金型10を用いた熱間プレス成形による熱間プレス成形品の製造方法について説明する。本実施形態による熱間プレス成形品の製造方法は、次の工程を備える。
・準備工程
・加熱工程
・熱間プレス成形工程
・離型工程
以下、各工程について説明する。 [Manufacturing method of hot press-formed product using mold 10]
A method for manufacturing a hot press-formed product by hot press-forming using the
・Preparation process ・Heating process ・Hot press molding process ・Mold releasing process Each process will be described below.
準備工程では、所望の化学組成を有する素材Bを準備する。本実施形態において、素材Bは特に限定されない。素材Bは例えば、鋼板である。素材Bが鋼板である場合、鋼板の種類は特に限定されない。素材Bは例えば、めっき処理等の表面処理がされた鋼板であってもよく、めっき処理等の表面処理がされていない鋼板(いわゆる裸材)であってもよい。めっき処理を実施する場合、めっき処理とは、溶融亜鉛めっき処理であってもよく、合金化溶融亜鉛めっき処理であってもよく、アルミニウムめっき処理であってもよい。 [Preparation process]
In the preparation step, a material B having a desired chemical composition is prepared. In this embodiment, the material B is not particularly limited. Material B is, for example, a steel plate. When the material B is a steel plate, the type of steel plate is not particularly limited. The material B may be, for example, a steel plate subjected to surface treatment such as plating, or may be a steel plate not subjected to surface treatment such as plating (so-called bare material). When the plating treatment is performed, the plating treatment may be a hot dip galvanizing treatment, an alloyed hot dip galvanizing treatment, or an aluminum plating treatment.
加熱工程では、準備された素材BをAc3点以上の温度に加熱する。加熱温度がAc3点未満であれば、素材Bがオーステナイト単相にならない。この場合、熱間プレス成形工程で素材Bを冷却したとき、素材Bのうち、第1急冷領域114及び第2急冷領域124に挟まれた領域において、硬質相(マルテンサイト及び/又はベイナイト)の形成が不十分となる。そのため、十分な強度が得られない場合がある。加熱温度がAc3点以上であれば、熱間プレス成形工程前の素材Bはオーステナイト単相となる。そのため、熱間プレス成形工程で素材Bを冷却したとき、素材Bのうち、第1急冷領域114及び第2急冷領域124に挟まれた領域において、硬質相が十分に形成される。その結果当該領域の強度を高めることができる。 [Heating process]
In the heating step, the prepared material B is heated to a temperature of Ac3 or higher. If the heating temperature is less than the Ac3 point, the material B will not become an austenite single phase. In this case, when the material B is cooled in the hot press forming process, the hard phase (martensite and/or bainite) is formed in the area sandwiched between the first
熱間プレス成形工程では、Ac3点以上に加熱された素材Bを、上述の金型10を用いて熱間プレス成形する。熱間プレス成形工程では、加熱工程で加熱された素材Bが下型12の第2成形面120の上に載置される。その後、図3に示すように、上型11を下型12に相対的に接近させて、金型10を閉じる。このとき、素材Bは上型11の第1成形面110及び下型12の第2成形面120と接触する。換言すれば、素材Bは、上型11の第1成形面110及び下型12の第2成形面120に挟まれる。上型11及び下型12により、素材Bに対して熱間プレス成形を実施する。 [Hot press molding process]
In the hot press-molding step, the material B heated to the Ac 3 point or higher is hot press-molded using the above-described
離型工程では、熱間プレス成形された素材Bを、金型10から離型して、熱間プレス成形品を製造する。ここで、離型工程において、金型10から離型されたときの素材B(熱間プレス成形品)の温度を、冷却停止温度と定義する。例えば、冷却停止温度が熱間プレス成形品のMf点~Ms点の間、又は、Ms点超~500℃の間であれば、熱間プレス成形品のミクロ組織として、硬質相からなる組織、又は、硬質相及び残留オーステナイトからなる組織が得られる。この場合、得られた熱間プレス成形品は優れた衝撃吸収能を有する。したがって、好ましくは、本実施形態による離型工程では、素材Bのうち、第1緩冷却領域113及び第2緩冷却領域123に挟まれた領域の温度が、素材Bの化学組成から求められるMf点~Ms点の間、又は、Ms点超~500℃の間であるときに、素材Bを金型10から離型する。 [Mold release process]
In the mold release step, the hot press-formed material B is released from the
本実施形態による熱間プレス成形品の製造方法はさらに、上記以外の他の製造工程を含んでもよい。例えば、本実施形態による熱間プレス成形品の製造方法は、離型工程後に、500℃以下の温度域での加熱保持工程を実施してもよい。 [Other processes]
The method for manufacturing a hot press-formed product according to the present embodiment may further include manufacturing steps other than those described above. For example, in the method for manufacturing a hot press-formed product according to the present embodiment, a heating and holding step in a temperature range of 500° C. or less may be performed after the mold release step.
10 金型
11 上型
110 第1成形面
111 第1リブ部
112 第1溝部
113 第1緩冷却領域
12 下型
120 第2成形面
121 第2リブ部
122 第2溝部
123 第2緩冷却領域 1
Claims (9)
- 素材に対して熱間プレス成形を実施するための金型であって、
第1成形面を有する上型と、
熱間プレス成形時において、前記第1成形面と対向して配置され、前記第1成形面とともに前記素材を熱間プレス成形する第2成形面を有する下型とを備え、
前記第1成形面は、
複数の第1リブ部と複数の第1溝部とを有する第1緩冷却領域を含み、
複数の前記第1リブ部は、前記第1リブ部の幅方向に配列され、
複数の前記第1溝部は、前記第1溝部の幅方向に配列され、
前記第1リブ部は、隣り合う前記第1溝部の間に形成されており、
前記第1リブ部の幅は、前記第1溝部の幅よりも狭く、
前記第2成形面は、
複数の第2リブ部と複数の第2溝部とを有する第2緩冷却領域を含み、
複数の前記第2リブ部は、前記第2リブ部の幅方向に配列され、
複数の前記第2溝部は、前記第2溝部の幅方向に配列され、
前記第2リブ部は、隣り合う前記第2溝部の間に形成されており、
前記第2リブ部の幅は、前記第2溝部の幅よりも狭く、
熱間プレス成形時において、前記第1緩冷却領域及び前記第2緩冷却領域を、前記第1緩冷却領域の法線方向から見たとき、
前記第1リブ部と前記第2リブ部とは、少なくとも一部が重複している、
金型。 A mold for performing hot press molding on a material,
an upper mold having a first molding surface;
a lower mold having a second molding surface that is arranged to face the first molding surface and hot press molds the material together with the first molding surface during hot press molding;
The first molding surface is
including a first slow cooling region having a plurality of first ribs and a plurality of first grooves;
The plurality of first rib portions are arranged in the width direction of the first rib portion,
The plurality of first grooves are arranged in the width direction of the first grooves,
The first rib portion is formed between the adjacent first groove portions,
The width of the first rib portion is narrower than the width of the first groove portion,
The second molding surface is
including a second slow cooling region having a plurality of second ribs and a plurality of second grooves;
The plurality of second rib portions are arranged in the width direction of the second rib portion,
The plurality of second grooves are arranged in the width direction of the second grooves,
The second rib portion is formed between the adjacent second groove portions,
The width of the second rib portion is narrower than the width of the second groove portion,
During hot press forming, when the first slow cooling region and the second slow cooling region are viewed from the normal direction of the first slow cooling region,
At least a portion of the first rib portion and the second rib portion overlap,
Mold. - 請求項1に記載の金型であって、
熱間プレス成形時において、前記第1緩冷却領域及び前記第2緩冷却領域を、前記第1緩冷却領域の法線方向から見たとき、
前記第1リブ部と前記第2リブ部とは、同じ方向に延びており、
前記第1溝部と前記第2溝部とは、同じ方向に延びている、
金型。 A mold according to claim 1,
During hot press forming, when the first slow cooling region and the second slow cooling region are viewed from the normal direction of the first slow cooling region,
The first rib portion and the second rib portion extend in the same direction,
The first groove and the second groove extend in the same direction,
Mold. - 請求項1又は請求項2に記載の金型であって、
前記第1リブ部の幅は、前記第1溝部の幅の10~50%であり、
前記第2リブ部の幅は、前記第2溝部の幅の10~50%である、
金型。 The mold according to claim 1 or claim 2,
The width of the first rib portion is 10 to 50% of the width of the first groove portion,
The width of the second rib portion is 10 to 50% of the width of the second groove portion,
Mold. - 請求項1~3のいずれか1項に記載の金型であって、
前記第1緩冷却領域の少なくとも一部において、
前記第1リブ部の幅は、1.0~8.0mmであり、
前記第1リブ部の高さは、0.2~5.0mmであり、
前記第2緩冷却領域の少なくとも一部において、
前記第2リブ部の幅は、1.0~8.0mmであり、
前記第2リブ部の高さは、0.2~5.0mmである、
金型。 The mold according to any one of claims 1 to 3,
In at least part of the first slow cooling region,
The width of the first rib portion is 1.0 to 8.0 mm,
The height of the first rib portion is 0.2 to 5.0 mm,
In at least part of the second slow cooling region,
The width of the second rib portion is 1.0 to 8.0 mm,
The height of the second rib portion is 0.2 to 5.0 mm,
Mold. - 請求項2に記載の金型であって、
前記第1リブ部の幅は、前記第1溝部の幅の10~50%であり、
前記第2リブ部の幅は、前記第2溝部の幅の10~50%であり、
前記第1リブ部及び前記第2リブ部の各々の幅は1.0~8.0mmであり、
前記第1リブ部及び前記第2リブ部の各々の高さは0.2~5.0mmであり、
式(1)で定義されるFn1が14以下である、
金型。
Fn1=Wr0.9/P00.8+0.05Hr (1)
ここで、式(1)中のWrは前記第1リブ部及び前記第2リブ部の幅(mm)であり、P0=Wr/Wsであり、Wsは前記第1溝部及び前記第2溝部の幅(mm)であり、Hrは前記第1リブ部及び前記第2リブ部の高さ(mm)である。 A mold according to claim 2,
The width of the first rib portion is 10 to 50% of the width of the first groove portion,
The width of the second rib portion is 10 to 50% of the width of the second groove portion,
The width of each of the first rib portion and the second rib portion is 1.0 to 8.0 mm,
Each height of the first rib portion and the second rib portion is 0.2 to 5.0 mm,
Fn1 defined by formula (1) is 14 or less,
Mold.
Fn1= Wr0.9 / P00.8 +0.05Hr (1)
Here, Wr in the formula (1) is the width (mm) of the first rib portion and the second rib portion, P0 = Wr/Ws, and Ws is the width of the first groove portion and the second groove portion. is the width (mm), and Hr is the height (mm) of the first rib portion and the second rib portion. - 請求項2又は請求項5に記載の金型であって、
前記第1リブ部の幅は、前記第1溝部の幅の10~50%であり、
前記第2リブ部の幅は、前記第2溝部の幅の10~50%であり、
前記第1リブ部及び前記第2リブ部の各々の幅は1.0~8.0mmであり、
前記第1リブ部及び前記第2リブ部の各々の高さは0.2~5.0mmであり、
式(2)で定義されるFn2が30以上である、
金型。
Fn2=Ws2×Hr0.4/Wr (2)
ここで、式(2)中のWsは前記第1溝部及び前記第2溝部の幅(mm)であり、Wrは前記第1リブ部及び前記第2リブ部の幅(mm)であり、Hrは前記第1リブ部及び前記第2リブ部の高さ(mm)である。 The mold according to claim 2 or claim 5,
The width of the first rib portion is 10 to 50% of the width of the first groove portion,
The width of the second rib portion is 10 to 50% of the width of the second groove portion,
The width of each of the first rib portion and the second rib portion is 1.0 to 8.0 mm,
Each height of the first rib portion and the second rib portion is 0.2 to 5.0 mm,
Fn2 defined by formula (2) is 30 or more,
Mold.
Fn2=Ws2* Hr0.4 /Wr ( 2 )
Here, Ws in the formula (2) is the width (mm) of the first groove portion and the second groove portion, Wr is the width (mm) of the first rib portion and the second rib portion, and Hr is the height (mm) of the first rib portion and the second rib portion. - 請求項4~請求項6のいずれか1項に記載の金型であって、
前記第1緩冷却領域の少なくとも一部において、
前記第1リブ部の幅は、1.0~4.0mmであり、かつ、前記第1溝部の幅の10~30%であり、
前記第2緩冷却領域の少なくとも一部において、
前記第2リブ部の幅は、1.0~4.0mmであり、かつ、前記第2溝部の幅の10~30%である、
金型。 The mold according to any one of claims 4 to 6,
In at least part of the first slow cooling region,
The width of the first rib portion is 1.0 to 4.0 mm and 10 to 30% of the width of the first groove portion,
In at least part of the second slow cooling region,
The width of the second rib portion is 1.0 to 4.0 mm, and 10 to 30% of the width of the second groove portion.
Mold. - 熱間プレス成形品の製造方法であって、
素材を準備する工程と、
前記準備された素材をAc3点以上の温度に加熱する工程と、
加熱された前記素材に対して、請求項1~請求項7のいずれか1項に記載の金型により熱間プレス成形を実施する工程と、
熱間プレス成形された前記素材を、前記金型から離型して、熱間プレス成形品を製造する工程とを備える、
熱間プレス成形品の製造方法。 A method for manufacturing a hot press-formed product,
a process of preparing materials;
heating the prepared material to a temperature of A c 3 or higher;
A step of performing hot press molding on the heated material using the mold according to any one of claims 1 to 7;
A step of releasing the hot press-formed material from the mold to produce a hot press-formed product;
A method for producing a hot press-formed product. - 請求項8に記載の熱間プレス成形品の製造方法であってさらに、
前記金型から離型して製造された前記熱間プレス成形品を、100~500℃で保持する工程とを備える、
熱間プレス成形品の製造方法。 A method for manufacturing a hot press-formed product according to claim 8, further comprising:
A step of holding the hot press-formed product produced by releasing from the mold at 100 to 500 ° C.
A method for producing a hot press-formed product.
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CN202280024788.2A CN117177825A (en) | 2021-03-30 | 2022-03-30 | Mold and method for producing hot-pressed molded article |
JP2023511480A JP7477809B2 (en) | 2021-03-30 | 2022-03-30 | Method for manufacturing mold and hot press molded product |
KR1020237035493A KR20230158086A (en) | 2021-03-30 | 2022-03-30 | Manufacturing methods of molds and hot press molded products |
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013248632A (en) * | 2012-05-31 | 2013-12-12 | Jfe Steel Corp | Warm press forming method and forming die having groove shape on surface of die, which is used for the same |
JP2014079790A (en) * | 2012-10-17 | 2014-05-08 | Honda Motor Co Ltd | Hot press molding method and die |
JP2014117735A (en) * | 2012-12-18 | 2014-06-30 | Kawasaki Heavy Ind Ltd | Spinning molding device |
JP2015000431A (en) * | 2013-06-18 | 2015-01-05 | Jfeスチール株式会社 | Warm press forming method, forming die used in the warm press forming method, and vehicular skeleton component |
JP2020116610A (en) * | 2019-01-24 | 2020-08-06 | マツダ株式会社 | Hot press-working device |
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- 2022-03-30 JP JP2023511480A patent/JP7477809B2/en active Active
- 2022-03-30 CN CN202280024788.2A patent/CN117177825A/en active Pending
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Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2013248632A (en) * | 2012-05-31 | 2013-12-12 | Jfe Steel Corp | Warm press forming method and forming die having groove shape on surface of die, which is used for the same |
JP2014079790A (en) * | 2012-10-17 | 2014-05-08 | Honda Motor Co Ltd | Hot press molding method and die |
JP2014117735A (en) * | 2012-12-18 | 2014-06-30 | Kawasaki Heavy Ind Ltd | Spinning molding device |
JP2015000431A (en) * | 2013-06-18 | 2015-01-05 | Jfeスチール株式会社 | Warm press forming method, forming die used in the warm press forming method, and vehicular skeleton component |
JP2020116610A (en) * | 2019-01-24 | 2020-08-06 | マツダ株式会社 | Hot press-working device |
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JP7477809B2 (en) | 2024-05-02 |
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