JP7135925B2 - Manufacturing method of bulge molding - Google Patents

Description

The present disclosure relates to methods of manufacturing bulge molded articles.

For example, automotive structural members such as body side members and suspension members are sometimes manufactured by bulging a metal plate (blank). In bulge molding, a plurality of metal plates are placed in a mold, a fluid is injected between the metal plates, and the metal plates are formed into a predetermined shape by internal pressure. Bulge molding is an excellent molding method that can easily mold even a member having a complicated shape.

Patent Literature 1 discloses a method for manufacturing a bulge molded product made of a metal plate. The manufacturing method uses first and second molds. The first and second molds each have a cavity having a shape corresponding to the outer shape of the bulge-molded product, and a flange surface for sandwiching the peripheral edges of the metal plates that are overlapped and joined. A convex or concave flow resistance increasing portion is provided on the flange surface of the first mold. According to Patent Document 1, during molding, the peripheral edge portion of the metal plate on the first mold side is aligned with the flow resistance increasing portion due to the internal pressure, so that the peripheral edge portion is suppressed from flowing into the cavity side. Molding defects such as wrinkles can be suppressed.

Japanese Patent No. 5609749

By the way, a tailored blank is sometimes used as a material for bulging. A tailored blank is formed by connecting metal plates having different materials and/or plate thicknesses. Therefore, in the tailored blank, one metal plate side has a large cross-sectional strength, and the other metal plate side has a low cross-sectional strength. In a bulge molded article formed by overlapping such tailored blanks, the positions of the boundary lines of the metal plates are generally aligned between the overlapped tailored blanks. When this boundary line is placed at the stretch flange deformation part of the bulge molded product, tensile strain (elongation strain) concentrates on the metal plate with the smaller cross-sectional strength among the metal plates connected to each other, and cracks occur. . The stretch-flange deformed portion refers to a portion where stretch strain is generated in the flange portion of the bulge-molded product during the molding process of the bulge-molded product. In addition, when the boundary line is arranged at the shrinkage flange deformation portion of the bulge-molded product, the compressive strain concentrates on the metal plate having the smaller cross-sectional strength, and buckling wrinkles may occur. The contraction flange deformation portion refers to a portion where compressive strain is generated in the flange portion of the bulge-molded product during the molding process of the bulge-molded product.

In a method for manufacturing a bulge-molded product using a tailored blank, the present disclosure alleviates strain concentration that occurs when the boundary line between metal plates that make up the tailored blank is arranged in the expansion or contraction flange deformation portion of the bulge-molded product. The task is to

A method for manufacturing a bulge molded product according to the present disclosure includes steps (a) and (b). In step (a), a plurality of tailored blanks to which a plurality of metal plates having different materials and/or plate thicknesses are connected are overlapped and their peripheral edges are joined. In step (b), a fluid is injected between a plurality of tailored blanks joined at their peripheries to form a bulge-formed article including stretch or shrink flange deformations. In the plurality of tailored blanks stacked in step (a), the positions of the boundary lines between the metal plates are separated from each other at the periphery. In the bulge molded article formed in step (b), each boundary line of the plurality of tailored blanks is located at a flange deformation and intersects a tensile or compressive stress direction at the flange deformation.

According to the present disclosure, in a method for manufacturing a bulge-molded product using a tailored blank, the strain concentration that occurs when the boundary line between the metal plates that constitute the tailored blank is arranged in the expansion or contraction flange deformation portion of the bulge-molded product can be mitigated.

FIG. 1 is a perspective view of a bulge molded product manufactured by a manufacturing method according to an embodiment. FIG. 2 is a perspective view of another bulge molded product manufactured by the manufacturing method according to the embodiment. FIG. 3A is a schematic diagram for explaining step (a) of the manufacturing method according to the embodiment. FIG. 3B is a schematic diagram for explaining step (b) of the manufacturing method according to the embodiment. FIG. 4 is a schematic diagram for explaining another aspect of the step (b) shown in FIG. 3B. FIG. 5 is a graph showing the relationship between the axial position in the stretch-flange deformed portion and the axial strain for the bulge-formed products according to Comparative Examples and Examples.

A method for manufacturing a bulge molded product according to an embodiment includes steps (a) and (b). In step (a), a plurality of tailored blanks to which a plurality of metal plates having different materials and/or plate thicknesses are connected are overlapped and their peripheral edges are joined. In step (b), a fluid is injected between a plurality of tailored blanks joined at their peripheries to form a bulge-formed article including stretch or shrink flange deformations. In the plurality of tailored blanks stacked in step (a), the positions of the boundary lines between the metal plates are separated from each other at the periphery. In the bulge molded article formed in step (b), each boundary line of the plurality of tailored blanks is located at a flange deformation and intersects a tensile or compressive stress direction at the flange deformation.

In the bulge-formed product manufactured by the manufacturing method according to the embodiment, the boundary line of the tailored blank is arranged at the extension or contraction flange deformation portion. However, since the positions of the boundary lines between the overlapped tailored blanks are separated from each other, the cross-sectional strength of the bulge molded product changes stepwise in the direction intersecting the boundary line. Therefore, strain concentration is less likely to occur on one side of the metal plate in the deformed portion of the flange. That is, according to the manufacturing method according to the embodiment, it is possible to alleviate the strain concentration that occurs when the boundary line between the metal plates that constitute the tailored blank is arranged in the expansion or contraction flange deformation portion of the bulge molded product.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In each figure, the same or corresponding configurations are denoted by the same reference numerals, and the same description will not be repeated.

[Bulge molded product]
First, the configuration of the bulge-molded product manufactured by the manufacturing method according to the embodiment will be described. FIG. 1 shows a perspective view of a first bulge-molded article 10 as an example of a bulge-molded article manufactured by the manufacturing method according to the embodiment. FIG. 2 shows a perspective view of a second bulge-molded article 20 as another example of the bulge-molded article manufactured by the manufacturing method according to the embodiment. The bulge molded products 10 and 20 are hollow members used as structural members for automobiles, for example. In this embodiment, the configurations of the bulge molded products 10 and 20 will be described with the top, bottom, left, and right in FIGS.

(First bulge molded product)
Referring to FIG. 1, a bulge molded product 10 is manufactured using tailored blanks 11 and 12 . The bulge molded product 10 includes a stretch flange deformed portion 101 . The stretch flange deformed portion 101 is a portion of the tailored blanks 11 and 12 in which tensile strain (elongation strain) in the axial direction (longitudinal direction) D ₁₀ occurs during bulge forming. form an arc. The stretch flange deformed portion 101 is formed on the side surface of the bulge molded product 10 .

The one surfaces of the tailored blanks 11 and 12 face each other. Peripheral edges of the tailored blanks 11 and 12 are joined together. Tailored blank 12 is arranged below tailored blank 11 .

The tailored blank 11 includes metal plates 111 and 112 having different materials and/or plate thicknesses. In this embodiment, the tensile strength of the metal plate 111 is greater than the tensile strength of the metal plate 112 due to the material difference from the metal plate 112 . Alternatively, the metal plate 111 is thicker than the metal plate 112 . Both the tensile strength and thickness of the metal plate 111 may be greater than those of the metal plate 112 .

In the tailored blank 11, the metal plates 111, 112 are connected to each other. A boundary line 113 between the metal plate 111 and the metal plate 112 intersects the axial direction D ₁₀ of the bulge-formed product 10 (the tensile stress direction of the stretch flange deformation portion 101). The boundary line 113 is arranged at the stretch flange deformed portion 101 in a side view of the bulge molded product 10 . That is, when the bulge-formed product 10 is viewed from the stretch-flange deformed portion 101 side, the boundary line 113 is arranged between the R blinds of the arc-shaped stretch-flange deformed portion 101 .

The tailored blank 12 includes metal plates 121 and 122 having different materials and/or plate thicknesses. In this embodiment, the tensile strength of the metal plate 121 is greater than that of the metal plate 122 due to the material difference between the metal plate 121 and the metal plate 122 . Alternatively, the metal plate 121 has a thickness greater than that of the metal plate 122 . Both the tensile strength and thickness of the metal plate 121 may be greater than those of the metal plate 122 . The material and thickness of the metal plate 121 can be the same as the material and thickness of the metal plate 111 of the tailored blank 11 . The material and thickness of the metal plate 122 can be the same as the material and thickness of the metal plate 112 of the tailored blank 11 .

In the tailored blank 12, the metal plates 121, 122 are connected to each other. A boundary line 123 between the metal plate 121 and the metal plate 122 intersects the axial direction D ₁₀ of the bulge molded product 10 (the tensile stress direction of the stretch flange deformation portion 101). The boundary line 123 is arranged at the stretch flange deformed portion 101 in a side view of the bulge molded product 10 . That is, when the bulge-formed product 10 is viewed from the stretch-flange deformed portion 101 side, the boundary line 123 is arranged between the R blinds of the arc-shaped stretch-flange deformed portion 101 .

In a side view of the bulge molded product ₁₀ , the boundary line 123 of the tailored blank 12 is shifted from the boundary line 113 of the tailored blank 11 in the axial direction D10. That is, the positions of the boundary lines 113 and 123 are separated from each other at the periphery of the bulge molded product 10 (tailored blanks 11 and 12). In FIG. 1 , the boundary line 113 of the tailored blank 11 is arranged to the left of the boundary line 123 of the tailored blank 12 . The distance in the axial direction D ₁₀ between the boundary lines 113 and 123 can be appropriately determined according to the strength of strain occurring in the stretch flange deformed portion 101 and the like. In the peripheral portion of the bulge molded product ₁₀ , the distance in the axial direction D10 between the boundary lines 113 and 123 is not particularly limited, but is, for example, 25 mm or more, or the thickness of the overlapped tailored blanks 11 and 12. more than 10 times the total height.

In this embodiment, the bulge molded product 10 in which the boundary lines 113 and 123 do not intersect in plan view is exemplified. However, the boundary lines 113 and 123 may intersect when the bulge-molded product 10 is viewed from above. That is, boundary lines 113 and 123 may be substantially parallel or may be in a twisted positional relationship. The boundary lines 113 and 123 are at least the peripheral edge of the bulge-molded product ₁₀ , and may be separated in the axial direction _D10 , and may include portions that are not separated in the axial direction D10.

Since the positions of the boundary lines 113 and 123 in the axial direction D10 are different in the peripheral portion of the bulge-molded product ₁₀ , the cross-sectional strength of the bulge-molded product ₁₀ changes stepwise in the axial direction D10. Here, in the present embodiment, the strength TS·t of the cross section (cross section) perpendicular to the axial direction D10 of the bulge molded product ₁₀ is defined as (TS1×t1)+(TS2×t2). TS1 and t1 are the tensile strength [MPa] and plate thickness [mm] of the tailored blank 11 in the cross section of the bulge molded product 10, respectively. TS2 and t2 are the tensile strength [MPa] and plate thickness [mm] of the tailored blank 12 in the cross section of the bulge molded product 10, respectively.

In the bulge molded product 10 shown in FIG. 1, a region A1 on the left side of the boundary line 113 of the tailored blank 11 is composed of metal plates 111 and 121 having large tensile strengths TS1 and TS2 and/or plate thicknesses t1 and t2. ing. Therefore, in the region A1, the cross-sectional strength TS·t of the bulge molded product 10 is large. The region A2 between the boundary line 113 of the tailored blank 11 and the boundary line 123 of the tailored blank 12 includes the metal plate 111 having a large tensile strength TS1 and/or a plate thickness t1 and the tensile strength TS2 and/or a plate thickness t2 being small. It is configured with a metal plate 122 . Therefore, the cross-sectional strength TS·t of the bulge-formed product 10 in the region A2 is smaller than the cross-sectional strength TS·t of the bulge-formed product 10 in the region A1. A region A3 on the right side of the boundary line 123 of the tailored blank 12 is composed of metal plates 112, 122 having small tensile strengths TS1, TS2 and/or plate thicknesses t1, t2. Therefore, the cross-sectional strength TS·t of the bulge-formed product 10 in the region A3 is smaller than the cross-sectional strength TS·t of the bulge-formed product 10 in the region A2. Thus, the cross-sectional strength of the bulge molded product ₁₀ decreases in the order of area A1, area A2, and area A3 along the axial direction D10.

(Second bulge molded product)
Referring to FIG. 2, the bulge molded product 20 is manufactured using tailored blanks 11 and 12, like the bulge molded product 10. As shown in FIG. The bulge molded product 20 includes a stretch flange deformed portion 201 . The stretch flange deformed portion 201 is a portion of the tailored blanks 11 and 12 where tensile strain in the axial direction D20 is generated during bulge forming, and forms a concave circular arc shape inside the bulge formed product ₂₀ . In the bulge molded product 20, stretch flange deformed portions 201 are formed on both side surfaces thereof.

In the bulge-formed product 20 as well, the boundary line 113 of the tailored blank 11 and 123 of the tailored blank 12 are arranged in the stretch flange deformed portion 201 in side view. That is, the boundary lines 113 and 123 are arranged between the R stops of the arc-shaped stretch flange deformation portion 201 in the side view of the bulge molded product 20 .

In the bulge-molded product ₂₀ , the boundary lines 113 and 123 each extend so as to intersect the axial direction D20. In other words, the boundary lines 113 and 123 intersect the tensile stress direction in the stretch flange deformed portion 201 . However, the positions of the boundary lines 113 and 123 are separated in the axial direction D20 when the bulge molded product ₂₀ is viewed from the side. Therefore, the cross-sectional strength of the bulge-molded product ₂₀ changes stepwise along the axial direction D20, like the bulge-molded product 10. As shown in FIG.

That is, in the bulge molded product 20, the area A1 on the left side of the boundary line 113 of the tailored blank 11 is composed of metal plates 111 and 121 having large tensile strengths TS1 and TS2 and/or plate thicknesses t1 and t2. , and its cross-sectional strength TS·t is large. The region A2 between the boundary line 113 of the tailored blank 11 and the boundary line 123 of the tailored blank 12 includes the metal plate 111 having a large tensile strength TS1 and/or a plate thickness t1 and the tensile strength TS2 and/or a plate thickness t2 being small. Since it is composed of the metal plate 122, it has a cross-sectional strength TS·t smaller than the cross-sectional strength TS·t of the region A1. Since the area A3 on the right side of the boundary line 123 of the tailored blank 12 is composed of metal plates 112 and 122 with small tensile strengths TS1 and TS2 and/or plate thicknesses t1 and t2, the cross-sectional strength TS t of the area A2 is has a cross-sectional strength TS·t smaller than The cross-sectional strength of the bulge molded product ₂₀ decreases in the order of area A1, area A2, and area A3 along the axial direction D20.

[Manufacturing method of bulge molded product]
Next, a method for manufacturing a bulge-molded product will be described. The manufacturing method includes a step (a) of overlapping the tailored blanks 11 and 12 and joining their peripheral edges, and injecting a fluid between the tailored blanks 11 and 12 to form the bulge molded product 10 or the bulge molded product 20. and a step (b) of molding.

(Step (a))
FIG. 3A is a schematic diagram for explaining step (a). Referring to FIG. 3A, first, tailored blanks 11 and 12 as forming materials are prepared. The tailored blanks 11 and 12 are, for example, so-called tailored weld blanks in which a plurality of metal plates having different materials and/or plate thicknesses are butted and joined together, or so-called tailor welded blanks in which the plate thickness is changed for each part during rolling of the metal plate. Rolled blanks and the like.

As described above, the tailored blank 11 includes metal plates 111 and 112 having different materials and/or plate thicknesses. The tailored blank 12 includes metal plates 121 and 122 having different materials and/or plate thicknesses. When the tailored blanks 11, 12 are tailored welded blanks, the metal plates 111, 112, 121, 122 are originally separate metal plates. That is, the metal plates 111 and 112 are joined together by abutting their edges. Similarly, the metal plates 121 and 122 are butted and joined at their edges. When the tailored blank 11 is a tailored rolled blank, the metal plates 111 and 112 are parts of one metal plate and are adjacent portions of the metal plate. Similarly, when the tailored blank 12 is a tailored rolled blank, the metal plates 121 and 122 are portions of one metal plate and are adjacent portions of the metal plate.

The material and plate thickness of the metal plates 111, 112, 121, 122 are not particularly limited. The metal plates 111 , 112 , 121 , 122 may be made of a material that can be molded and have a plate thickness that can be molded. As the metal plates 111, 112, 121, 122, for example, hot-rolled steel plates, cold-rolled steel plates, plated steel plates, and alloy plates such as Al, Cu, and Ti can be used. Alternatively, the metal plates 111 , 112 , 121 , 122 may be formed by laminating a plurality of metal plates or by laminating a non-metallic material on a metal plate (so-called laminated plate). The plate thickness of the metal plates 111, 112, 121, 122 is selected according to the material thereof or the shape of the bulge-molded products 10, 20. For example, the thickness is within the range of 0.5 mm to 5.0 mm. preferable.

Next, the prepared tailored blanks 11 and 12 are overlapped and their peripheral edge portions are joined. Examples of means for joining the peripheral edge portions of the tailored blanks 11 and 12 include welding such as laser welding or seam welding, adhesives, or combined use of spot welding and adhesives. At the peripheries of the overlapped tailored blanks 11 and 12, the position of the boundary line 113 of the tailored blank 11 and the position of the boundary line 123 of the tailored blank 12 are separated in the axial direction. FIG. 3A shows metal plates 111 and 112 having the same thickness and different materials (tensile strength), and metal plates 121 and 122 having the same thickness and different materials (tensile strength).

(Step (b))
FIG. 3B is a schematic diagram for explaining step (b). With reference to FIG. 3B, in step (b), the tailored blanks 11 and 12 whose peripheral edges are joined are arranged in a mold 30 . The mold 30 includes an upper mold 31 and a lower mold 32 . The upper mold 31 has a cavity 311 and a flange surface 312 . Lower mold 32 has cavity 321 and flange surface 322 . The cavities 311 and 321 have a shape corresponding to the outer shape of the bulge molded product 10 ( FIG. 1 ) including the stretch flange deformed portion 101 or the outer shape of the bulge molded product 20 ( FIG. 2 ) including the stretch flange deformed portion 201 . Peripheral edges of the tailored blanks 11 and 12 are arranged between the flange surfaces 312 and 322 . Between the flange surfaces 312, 322 and the peripheries of the tailored blanks 11, 12, a slight gap of about 0.05 mm to 0.1 mm is normally provided.

In FIG. 3B, the flange surfaces 312, 322 are configured as flat surfaces. However, if the thickness of the metal plates 111 and 121 and the thickness of the metal plates 112 and 122 are different, the flange surfaces 312 and 322 have steps corresponding to the difference in plate thickness as shown in FIG. good too.

Returning to FIG. 3B, a fluid is injected between the tailored blanks 11 and 12 arranged in the mold 30 to pressurize the interior of the tailored blanks 11 and 12 . This fluid may be a liquid such as water or oil, or a gas such as air or nitrogen gas. As a result, the tailored blanks 11 and 12 are deformed and pressed against the inner wall surfaces of the cavities 311 and 321 to form the bulge molded product 10 (FIG. 1) or bulge molded product 20 (FIG. 2). At this time, stretch flanging deformation occurs at the boundary lines 113 and 123 of the tailored blanks 11 and 12 .

[Effects of Embodiment]
In the bulge molded products 10 and 20 manufactured by the manufacturing method according to the present embodiment, boundary lines 113 and 123 of the tailored blanks 11 and 12 are arranged in the stretch flange deformation portions 101 and 201 . However, the positions of the boundary lines 113 and 123 are separated in the axial directions D ₁₀ and D ₂₀ at the peripheral edge portions of the tailored blanks 11 and 12 . Therefore, the cross-sectional strength TS·t of the bulge molded products 10 and 20 changes stepwise along the axial directions D ₁₀ and D ₂₀ . Therefore, in the stretch flange deformation portions 101 and 201, the tensile strain in the axial directions D ₁₀ and D ₂₀ is less likely to concentrate on the side where the cross-sectional strength is small. That is, strain concentration in the stretch flange deformation portions 101 and 201 can be alleviated, and cracks and the like can be prevented from occurring.

Although the embodiments according to the present disclosure have been described above, the present disclosure is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present disclosure.

In the above embodiment, an example in which the boundary lines 113 and 123 of the tailored blanks 11 and 12 are arranged in the stretch flange deformed portions 101 and 201 of the bulge molded products 10 and 20 was described. may be placed in the contraction flange deformation of the In this case as well, each boundary line intersects the compressive stress direction (the axial direction of the bulge molded product), and the positions of the boundary lines are axially spaced apart at the peripheries of the overlapped tailored blanks. As a result, in the contraction flange deformed portion, the concentration of the axial compressive strain on the side having the smaller cross-sectional strength can be alleviated. In addition, it is possible to suppress partial thinning of the bulge-molded product, and to improve part performance.

In the above embodiment, two tailored blanks 11 and 12 are used to manufacture the bulge molded products 10 and 20 . However, three or more tailored blanks can be used to produce a bulge molded product. In addition, each tailored blank may be produced by joining three or more separate metal plates to each other, or three or more portions having different plate thicknesses are provided when rolling one metal plate. It may be made by That is, each tailored blank can also include three or more metal plates with different materials and/or plate thicknesses.

When three or more metal plates with different materials and/or plate thicknesses are included in the tailored blank, a plurality of boundary lines between the metal plates are present in the tailored blank. In this case, in the peripheral edge portions of the plurality of tailored blanks that are superimposed on each other, the positions of at least some of the boundary lines may be separated, and the positions of the other boundary lines may be the same. Further, among the plurality of boundary lines present in the tailored blank, at least some boundary lines need only be arranged in the flange deformation portion, and the other boundary lines need not be arranged in the flange deformation portion. In addition, even if the boundary line is arranged in the flange deformation portion, it is not necessary to arrange the entirety thereof in the flange deformation portion, and a part thereof may be arranged in the flange deformation portion.

The present disclosure will be described in more detail below by way of examples. However, the present disclosure is not limited to the following examples.

In order to confirm the effect of the method for manufacturing a bulge-molded product according to the present disclosure, bulge-molded products (comparative examples and examples) having the same shape as the bulge-molded product 10 shown in FIG. A numerical analysis (FEM analysis) and a model test were carried out.
<Common conditions>
・Tensile strength of metal plates 111 and 121: 590 MPa
・Thickness of metal plates 111 and 121: 1.4 mm
・Tensile strength of the metal plates 112, 122: 270 MPa
・Thickness of metal plates 112 and 122: 1.4 mm
<Comparative example>
- Axial position of boundary lines 113 and 123: same <Example>
Axial position of the boundary line 113: A position ₁₅ mm apart in the axial direction D10 from the boundary lines 113 and 123 in the comparative example Axial position of the boundary line 123: Axial direction _D10 from the boundary lines 113 and 123 in the comparative example −15 mm away (opposite side of boundary line 113)

FIG. 5 is the result of FEM analysis, and is a graph showing the relationship between the axial position in the stretch flange deformed portion 101 and the axial strain for the bulge molded product 10 according to Comparative Example and Example. As shown in FIG. 5, in an embodiment in which the axial positions of the boundary lines 113 and 123 are different between the tailored blanks 11 and 12, the axial positions of the boundary lines 113 and 123 are the same between the tailored blanks 11 and 12. The axial strain is smaller than that of the comparative example. By making the axial positions of the boundary lines 113 and 123 different between the tailored blanks 11 and 12, the difference in cross-sectional strength on both sides of the boundary line 113 and the difference in cross-sectional strength on both sides of the boundary line 123 are reduced. This is because the concentration of strain on the side where the cross-sectional strength is small is relaxed.

In the model test, cracks occurred in the stretch flange deformed portion 101 when manufacturing the bulge molded product 10 according to the comparative example. On the other hand, when the bulge-formed product 10 according to the example was produced, no cracks or wrinkles occurred in the stretch flange deformed portion 101 .

From the above, it was confirmed that according to the method for manufacturing a bulge-formed product according to the present disclosure, strain concentration in the flange deformation portion is alleviated, and cracks and wrinkles in the flange deformation portion are suppressed.

Reference Signs List 10, 20: Bulge molded product 101, 201: Flange deformed portion 11, 12: Tailored blank 111, 112, 121, 122: Metal plate 113, 123: Boundary

Claims (1)

A method for manufacturing a bulge molded product,
(a) a step of superimposing a plurality of tailored blanks to which a plurality of metal plates having different materials and/or plate thicknesses are connected and joining the peripheral edges thereof;
(b) injecting a fluid between the plurality of tailored blanks having the peripheral edge portions joined together to form the bulge molded product including the stretch or shrink flange deformed portion;
with
In the plurality of tailored blanks superimposed in the step (a), the positions of the boundary lines between the metal plates are separated from each other at the peripheral edge portion,
In the bulge-formed product formed in the step (b), each of the boundary lines of the plurality of tailored blanks is arranged at the flange deformation and intersects a tensile or compressive stress direction at the flange deformation. Production method.

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