Production method of metal member

Abstract

To promote more uniform heating at the time of quenching.SOLUTION: Quenching is performed by irradiating at least one beam toward a target region including a ridge portion on an outer peripheral surface of a metal member and a peripheral portion adjacent to the ridge portion on the outer peripheral surface. The ridge portion extends along an extending direction, and a cross section of the ridge portion has a curved shape such that the outer peripheral surface protrudes. During quenching, the target region is moved along the ridge portion. The target region includes a high-intensity portion and a low-intensity portion. The high-intensity portion has a high beam intensity. The low-intensity portion has a lower beam intensity than the high-intensity portion. The low-intensity portion is located at the ridge portion, and the high-intensity portion is located at the peripheral portion.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing a metal member.

Background Art

[0002] There is known a technique of performing quenching by irradiating a beam toward the outer surface of a workpiece (for example, Patent Document 1). In the technique of Patent Document 1, the beam is irradiated along a portion extending in a ridge line shape in the workpiece (hereinafter, the ridge line portion), and thereby quenching is performed.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technique of Patent Document 1, when the beam is irradiated, the ridge line portion of the workpiece has less heat dissipation space than the peripheral portion adjacent to the ridge line portion, so it tends to become high temperature, and it is difficult to uniformly heat the ridge line portion and the peripheral portion. In particular, when the light source of the beam is located in front of the ridge line portion, the ridge line portion is likely to be overheated. For this reason, in the ridge line portion, there is a risk of damage such as melting and dropping, and there is also a risk that the peripheral portion cannot be sufficiently heated.

[0005] In one aspect of the present disclosure, it is desirable to promote more uniform heating during quenching.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a method for manufacturing a metal member, which includes performing quenching by irradiating at least one beam toward a target region including a ridge line portion on the outer peripheral surface of the metal member and a peripheral portion adjacent to the ridge line portion on the outer peripheral surface. The ridge line portion is a portion that extends along the stretching direction in the metal member and has a shape that bends so that the outer peripheral surface protrudes in a cross section orthogonal to the stretching direction. During quenching, the target region is relatively moved along the ridge line portion. The target region has a high-strength portion and a low-strength portion. The high-strength portion has a high beam intensity. The low-strength portion has a lower beam intensity than the high-strength portion. Further, the low-strength portion is located at the ridge line portion, and the high-strength portion is located at the peripheral portion.

[0007] According to the above configuration, since the low-strength portion in the target region is located at the ridge line portion, it is possible to suppress the ridge line portion from being overheated. Therefore, during quenching, it is possible to promote the ridge line portion and the peripheral portion to be heated more uniformly.

[0008] In one aspect of the present disclosure, a high-strength portion and a low-strength portion may be formed by irradiating a plurality of beams toward the target region. According to the above configuration, the low-strength portion and the high-strength portion can be preferably formed.

[0009] In one aspect of the present disclosure, the ridge line portion and the peripheral portion may be located in a plate-like portion of the metal member. According to the above configuration, it is possible to promote the ridge line portion and the peripheral portion to be heated more uniformly.

[0010] In one aspect of the present disclosure, the ridge line portion may be a portion where the length in the ridge line width direction, which is a direction along the outer peripheral surface and orthogonal to the stretching direction, substantially coincides with the effective width of the plate-like portion. The high-strength portion is located at the peripheral portion or the peripheral portion and the ridge line portion, and the low-strength portion may not be located at the peripheral portion.

[0011] According to the above configuration, it is possible to preferably perform quenching on the peripheral portion while suppressing damage to the ridge line portion. In one aspect of the present disclosure, the metal member may be a member formed by press molding.

[0012] According to the above configuration, it is possible to promote more uniform heating of the ridge line portion and the peripheral portion.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0014] Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. [1. First Embodiment] [(1) Outline] The manufacturing method of the metal member 1 (see FIG. 1) in the first embodiment includes a step of quenching the metal member 1 with a beam. The metal member 1 is a plate-shaped member made of metal (for example, iron), and is used as a part of a vehicle, more specifically, as a part of the vehicle body. Of course, the present invention is not limited to this, and the metal member 1 may be a member not mounted on the vehicle.

[0015] The metal member 1 is a groove-shaped member extending along the extending direction E, and includes a top portion 10, a first side surface portion 11, a first flange portion 11A, a second side surface portion 12, and a second flange portion 12A.

[0016] The top portion 10 is an elongated plate-shaped portion that extends planar in the extending direction E. At the center in the width direction of the top portion 10, a stepped portion 10A that extends in the extending direction E is formed. The first and second side portions 11, 12 are plate-shaped portions that protrude from both ends in the width direction of the top portion 10 and face each other in the width direction of the top portion 10. The first and second side portions 11, 12 each extend from the first end to the second end in the extending direction E of the top portion 10.

[0017] The first and second flange portions 11A, 12A are flange-shaped portions provided at the ends on the opposite side of the top portion 10 in the first and second side portions 11, 12. The first and second flange portions 11A, 12A each extend from the first end to the second end in the extending direction E in the first or second side portion 11, 12.

[0018] That is, the first and second side portions 11, 12 form an opening of the metal member 1 which is a groove-shaped member, and the first and second flange portions 11A, 12A are disposed on both sides of the opening. And the surfaces on the opposite side of the opening in the top portion 10 and the first and second side portions 11, 12 form the outer peripheral surface 13 of the metal member 1. As an example, plating (more specifically, hot dip galvanizing) may be applied to the outer peripheral surface 13.

[0019] [(2) Ridge line portion and peripheral portion] At the boundary between the top portion 10 and the first side portion 11, a ridge line portion 2 that extends straight along the extending direction E is formed (see FIGS. 1 and 2). That is, the ridge line portion 2 is formed at the boundary of two intersecting plate-shaped portions, and the outer peripheral surface 13 of the metal member 1 in a cross section (hereinafter simply referred to as a cross section) perpendicular to the extending direction E has a shape that is bent so as to protrude. In the first embodiment, as an example, the entire cross section of the ridge line portion 2 has a curved shape (see FIG. 3). However, it is not limited to this, and the cross section of the ridge line portion 2 may have a curved portion and a portion that extends planar, or may have a bent shape.

[0020] Further, the ridge line portion 2 has a length in the ridge line width direction W, which is a direction along the outer peripheral surface 13 and orthogonal to the extending direction E, that substantially coincides with the effective width be of the Karman in the metal member 1. The effective width be is calculated by, for example, the following formula.

[0021] [Number]

[0022] Here, E is the Young's modulus of the metal constituting the metal member 1, k is the restraint coefficient, ν is the Poisson's ratio, and σ y is the yield point (MPa), and t is the thickness (mm) of the metal member 1. Of course, the length of the ridge line portion 2 in the ridge line width direction W is not limited to the effective width be and can be appropriately determined.

[0023] That is, the ridge line portion 2 includes the boundary line between the top portion 10 and the first side surface portion 11, and has a portion adjacent to the boundary line in the top portion 10 and a portion adjacent to the boundary line in the first side surface portion 11. Further, the ridge line portion 2 extends from the first end to the second end in the metal member 1.

[0024] Further, the portion adjacent to the ridge line portion 2 in the top portion 10 and the portion adjacent to the ridge line portion 2 in the first side surface portion 11 are defined as the peripheral portion 3. That is, the peripheral portion 3 has two portions located on both sides of the ridge line portion 2. Further, the cross section of the peripheral portion 3 spreads in a planar shape. Further, the peripheral portion 3 also extends from the first end to the second end in the metal member 1.

[0025] [(3) Manufacturing method of metal member] The manufacturing method of the metal member 1 includes a step of forming the metal member 1 by press forming and a quenching step (see FIG. 3) of quenching the metal member 1. Note that the metal member 1 may be formed by a method other than press forming.

[0026] In the quenching step, at least one beam B is irradiated onto the ridge line portion 2 and the peripheral portion 3 on the outer peripheral surface 13 of the metal member 1, whereby these portions are heated. That is, a target area 4 irradiated with at least one beam B is formed at the first end of the extending direction E in the ridge line portion 2 and the peripheral portion 3. Then, for example, by moving the light source of at least one beam B and / or changing the irradiation direction of at least one beam B, the target area 4 is moved along the extending direction E from the first end to the second end of the extending direction E in the ridge line portion 2 and the peripheral portion 3 (see Fig. 2). That is, the target area 4 passes through the entire areas of the ridge line portion 2 and the peripheral portion 3. Thereby, at least one beam B is irradiated onto the entire areas of the ridge line portion 2 and the peripheral portion 3 to heat these portions.

[0027] In the quenching process, at least one beam B may be irradiated onto a part of the ridge line portion 2 and each peripheral portion 3. Also, at least one beam B may be irradiated onto the area of the outer peripheral surface 13 of the metal member 1 where the ridge line portion 2 and each peripheral portion 3 are located, or the beam may also be irradiated onto portions other than these portions on the outer peripheral surface 13. After the heating of the metal member 1 by the beam is completed, the metal member 1 is rapidly cooled.

[0028] [(4) Target area] The shape of the target area 4 can be determined as appropriate. Also, as an example, the target area 4 includes two high-strength portions 40 and one low-strength portion 41 (see Figs. 2 to 4). The intensity (W) of at least one beam B irradiated onto the high-strength portion 40 is higher than that of the low-strength portion 41.

[0029] Specifically, for example, the average value of the intensity of at least one beam B irradiated to the high-intensity part 40 may be higher than the average value of the intensity of at least one beam B irradiated to the low-intensity part 41. Also, for example, the lower limit value of the intensity of at least one beam B irradiated to the high-intensity part 40 may be higher than the upper limit value of the intensity of at least one beam B irradiated to the low-intensity part 41. Note that the low-intensity part 41 may include a region where the intensity of at least one beam B becomes zero. Also, in each of the high-intensity part 40 and the low-intensity part 41, the intensity of at least one beam B may be distributed substantially uniformly, or there may be a bias in the distribution of the intensity of at least one beam B. In the first embodiment, as an example, the intensity of the beam B in the high-intensity part 40 is substantially constant, and the intensity of the beam B in the low-intensity part 41 is zero (see FIGS. 3 and 4).

[0030] The low-intensity part 41 is an elongated region that extends from the first end to the second end of the target region 4 and has a constant width. Also, the high-intensity parts 40 are located on both sides of the low-intensity part 41. That is, the target region 4 has two high-intensity parts 40 arranged with the low-intensity part 41 in between.

[0031] And in the target region 4, the intensity distribution of at least one beam B is adjusted such that each high-intensity part 40 is located in the peripheral part 3, or the peripheral part 3 and the ridge line part 2, and the low-intensity part 41 is located in the ridge line part 2 but not in the peripheral part 3 (see FIGS. 3 and 4).

[0032] That is, the low-intensity part 41 is formed to overlap the ridge line part 2 and extends along the extending direction E. On the other hand, each high-intensity part 40 corresponds to the top part 10 and the first side surface part 11, and is formed to overlap the peripheral part 3 located in the corresponding top part 10 or the first side surface part 11. And the boundary between the low-intensity part 41 and each high-intensity part 40 overlaps the boundary between the ridge line part 2 and the peripheral part 3, or is located in the ridge line part 2. That is, each high-intensity part 40 may protrude from the ridge line part 2, but the low-intensity part 41 does not protrude from each peripheral part 3.

[0033] By setting the intensity of the beam B in the target area 4 in this way, due to quenching, as an example, the ridge line portion 2 rises to about 900 °C, and the peripheral portion 3 rises to about 850 °C. Of course, it is not limited to this. For example, the low-intensity portion 41 may protrude into the peripheral portion 3. That is, the high-intensity portion 40 may be located in the peripheral portion 3, and the low-intensity portion 41 may be located in the ridge line portion 2, or the ridge line portion 2 and the peripheral portion 3. Also, for example, the low-intensity portion 41 may protrude into the peripheral portion 3 and each high-intensity portion 40 may protrude into the ridge line portion 2. That is, the high-intensity portion 40 may be located in the peripheral portion 3, or the peripheral portion 3 and the ridge line portion 2, and the low-intensity portion 41 may be located in the ridge line portion 2, or the ridge line portion 2 and the peripheral portion 3. Also, for example, the low-intensity portion 41 may not protrude into each peripheral portion 3 and each high-intensity portion 40 may not protrude into the ridge line portion 2. That is, the high-intensity portion 40 may be located only in the peripheral portion 3, and the low-intensity portion 41 may be located only in the ridge line portion 2.

[0034] [(5) Beam] In the first embodiment, two beams B are irradiated onto the target area 4 from two light sources provided in each of the first and second semiconductor lasers 50 and 51, thereby forming the low-intensity portion 41 and each high-intensity portion 40 (see FIGS. 3 and 4).

[0035] More specifically, the light source of the first semiconductor laser 50 is arranged to face the top portion 10, and irradiates the beam B toward the peripheral portion 3 and the ridge line portion 2 located at the top portion 10. The light source of the second semiconductor laser 51 is arranged to face the first side surface portion 11, and irradiates the beam B toward the peripheral portion 3 and the ridge line portion 2 located at the first side surface portion 11.

[0036] And, as an example, the irradiation areas of the beams B from the first and second semiconductor lasers 50 and 51 form the high-intensity portions 40, and the boundaries of the irradiation areas are respectively located at the boundaries between the ridge line portion 2 and each peripheral portion 3 (see FIG. 3). And a low-intensity portion 41 is formed between the irradiation areas. Of course, it is not limited to this, and the boundary of the irradiation area of the beam B from the first and second semiconductor lasers 50 and 51 may be located in the ridge line portion 2 (see FIG. 4).

[0037] Further, for example, the region around the end of the irradiation region of the beams B from the first and second semiconductor lasers 50 and 51 may be located at the ridge line portion 2. Then, by adjusting the intensity of the beam B in this region to be relatively low, a low-intensity portion 41 may be formed at the ridge line portion 2 and high-intensity portions 40 may be formed at each peripheral portion 3.

[0038] Of course, the present invention is not limited to this, and the target region 4 may be formed by three or more beams B. Further, for example, the target region 4 may be formed by overlapping all or part of a plurality of beams B. Further, at least one beam B may be formed by a method different from that of the semiconductor laser.

[0039] [2. Second Embodiment] The manufacturing method of the metal member 1 in the second embodiment is different from the first embodiment in that quenching is performed using one beam B. Hereinafter, the differences from the first embodiment in the manufacturing method of the metal member 1 in the second embodiment will be mainly described.

[0040] In the second embodiment, by irradiating one beam B from one light source provided in the fiber laser 52, the same target region 4 as in the first embodiment is formed (see FIG. 5). The light source of the fiber laser 52 is located in front of the ridge line portion 2 and irradiates the beam B to the ridge line portion 2 and the peripheral portions 3 located at each of the top portion 10 and the first side surface portion 11.

[0041] Further, the fiber laser 52 has an optical element such as a DOE (Diffractive Optical Element), and the intensity of the beam B irradiated to the target region 4 is adjusted by the optical element, and in the same manner as in the first embodiment, two high-intensity portions 40 and a low-intensity portion 41 are formed.

[0042] [3. Effects] (1) According to the above embodiment, since the low-intensity portion 41 in the target region 4 is located at the ridge line portion 2 and each high-intensity portion 40 is located at the peripheral portion 3, it is possible to suppress the overheating of the ridge line portion 2. Therefore, during quenching, at least one beam B can be used to promote more uniform heating of the ridge line portion 2 and the peripheral portion 3.

[0043] (2) Further, in the first embodiment, in the quenching step, two high-intensity portions 40 and a low-intensity portion 41 in the target region 4 are formed by two beams B. Therefore, the high-intensity portion 40 and the low-intensity portion 41 can be preferably formed.

[0044] (3) Further, the ridge line portion 2 and the peripheral portion 3 are located at the boundary between the top portion 10, which is a plate-shaped portion, and the first side surface portion 11. Therefore, it is possible to promote more uniform heating of the ridge line portion 2 and the peripheral portion 3.

[0045] (4) Further, the length of the ridge line portion 2 in the ridge line width direction W substantially coincides with the effective width be of the metal member 1, and each high-intensity portion 40 is located at the peripheral portion 3 or at the peripheral portion 3 and the ridge line portion 2. Therefore, while suppressing damage to the ridge line portion 2, quenching can be preferably performed on the peripheral portion 3.

[0046] (5) Further, according to the above embodiment, it is possible to promote more uniform heating of the ridge line portion 2 and the peripheral portion 3 of the metal member 1 formed by press forming. [4. Other Embodiments] (1) The metal member 1 of the first and second embodiments is entirely composed of a plate-shaped portion. However, the present invention is not limited to this, and in a manufacturing method of a metal member in which a plate-shaped portion is partially provided, in the same manner as in the first and second embodiments, a quenching step may be performed on the ridge line portion and the peripheral portion in the plate-shaped portion. Further, the same quenching step as in the first and second embodiments may be performed on the ridge line portion and the peripheral portion formed in a non-plate-shaped portion of the metal member.

[0047] (2) The distributions of the high-intensity portions and the low-intensity portions in the target region 4 are not limited to those exemplified in the first and second embodiments, and can be determined as appropriate. Specifically, for example, in the target region, a low-intensity portion similar to those in the first and second embodiments and one high-intensity portion adjacent to the low-intensity portion may be provided. Then, in the quenching process, in the same manner as in the first and second embodiments, at least the intensity of one beam may be adjusted so that the low-intensity portion is located at the ridge line portion 2 and the high-intensity portion is located in the peripheral portion 3 included in the top portion 10 or the first side surface portion 11.

[0048] (3) In the first and second embodiments, the ridge line portion 2 and the peripheral portion 3 extend straight along the stretching direction E of the metal member 1. However, not limited thereto, the ridge line portion 2 and the peripheral portion 3 may have a bent shape as a whole or partially. Even in such a case, the quenching process can be carried out in the same manner.

[0049] (4) A plurality of functions of one component in the above embodiments may be realized by a plurality of components, or one function of one component may be realized by a plurality of components. Also, a plurality of functions of a plurality of components may be realized by one component, or one function realized by a plurality of components may be realized by one component. Further, a part of the configuration of the above embodiments may be omitted. Also, at least a part of the configuration of the above embodiments may be added to or replaced with the configuration of other above embodiments.

[0050] [5. Technical idea disclosed in this specification] [Item 1] A method for manufacturing a metal member, comprising performing quenching by irradiating at least one beam toward a target region including a ridge line portion on the outer peripheral surface of the metal member and a peripheral portion adjacent to the ridge line portion on the outer peripheral surface, wherein the ridge line portion is a portion extending along the stretching direction in the metal member and having a bent shape in a cross section orthogonal to the stretching direction such that the outer peripheral surface protrudes, During the quenching, the target area is relatively moved along the ridge line portion. The target area has a high-intensity portion where the intensity of the beam is high and a low-intensity portion where the intensity of the beam is lower than that of the high-intensity portion. The low-intensity portion is located at the ridge line portion, and the high-intensity portion is located at the peripheral portion. Method for manufacturing a metal member.

[0051] [Item 2] A method for manufacturing a metal member according to Item 1, wherein By irradiating the target area with a plurality of the beams, the high-intensity portion and the low-intensity portion are formed. Method for manufacturing a metal member.

[0052] [Item 3] A method for manufacturing a metal member according to Item 1 or Item 2, wherein The ridge line portion and the peripheral portion are located on the plate-like portion of the metal member. Method for manufacturing a metal member.

[0053] [Item 4] A method for manufacturing a metal member according to Item 3, wherein The ridge line portion is a portion where the length in the ridge line width direction, which is a direction along the outer peripheral surface and orthogonal to the extending direction, substantially coincides with the effective width of the plate-like portion. The high-intensity portion is located at the peripheral portion or at the peripheral portion and the ridge line portion, and the low-intensity portion is not located at the peripheral portion. Method for manufacturing a metal member.

[0054] [Item 5] A method for manufacturing a metal member according to any one of Items 1 to 4, wherein The metal member is a member formed by press forming. Method for manufacturing a metal member.

Explanation of Signs

[0055] B… beam, E… extending direction, W… ridge width direction, 1… metal member, 10… top, 10A… stepped portion, 11… first side surface portion, 11A… first flange portion, 12… second side surface portion, 12A… second flange portion, 13… outer peripheral surface, 2… ridge portion 2… peripheral portion 3… target area, 40… high-strength portion, 41… low-strength portion, 50… first semiconductor laser, 51… second semiconductor laser, 52… fiber laser.

Claims

1. A method for manufacturing a metal member, comprising: performing quenching by irradiating at least one beam toward a target region including a ridge line portion on an outer peripheral surface of the metal member and a peripheral portion adjacent to the ridge line portion on the outer peripheral surface; wherein the ridge line portion is a portion extending along the stretching direction of the metal member and having a shape bent such that the outer peripheral surface protrudes in a cross section orthogonal to the stretching direction; during the quenching, relatively moving the target region along the ridge line portion; the target region has a high-intensity portion where the intensity of the beam is high and a low-intensity portion where the intensity of the beam is lower than that of the high-intensity portion; the low-intensity portion is located at the ridge line portion, and the high-intensity portion is located at the peripheral portion A method for manufacturing a metal member.

2. The method for manufacturing a metal member according to claim 1, wherein the high-intensity portion and the low-intensity portion are formed by irradiating a plurality of the beams toward the target region A method for manufacturing a metal member.

3. The method for manufacturing a metal member according to claim 1 or claim 2, wherein the ridge line portion and the peripheral portion are located in a plate-like portion of the metal member A method for manufacturing a metal member.

4. The method for manufacturing a metal member according to claim 3, wherein the ridge line portion is a portion in a direction along the outer peripheral surface and orthogonal to the stretching direction, and the length in the ridge line width direction is substantially the same as the effective width of the plate-like portion; the high-intensity portion is located at the peripheral portion or the peripheral portion and the ridge line portion, and the low-intensity portion is not located at the peripheral portion A method for manufacturing a metal member.

5. The method for manufacturing a metal member according to claim 1 or claim 2, wherein the metal member is a member formed by press forming A method for manufacturing a metal member.

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