JP2006187786A - Method for connecting titanium thin sheet and connected member connected by using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a connecting method of titanium thin sheets by which there is no possibility of occurrence of break even when stress with deformation such as bending and twisting is imparted to the connected part and a connected member which is connected by using the same. <P>SOLUTION: By the connecting method of the titanium thin sheet, the mutual end parts of the titanium thin sheets 11a, 11b are butted and connected, a layered part 15 is formed by overlapping both faces of the titanium thin sheet 11a, 11b with non-titanium thin sheets 13a, 13b so as to cover the butt part 12 of the mutual end parts of the titanium thin sheet 11a, 11b and spot welding is performed in the layered part 15 at prescribed intervals. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for connecting titanium thin plates in which deformation such as bending or twisting is applied after connection.

  In recent years, demand for fuel cells has increased due to environmental problems. The cells of this fuel cell are required to have corrosion resistance because the fuel is accommodated, and titanium or stainless steel is used as a constituent material thereof. For example, a three-layer clad material having a laminated structure of Ti / stainless steel / Ti is used as a constituent material of the fuel cell. In order to continuously produce the titanium thin plate constituting the three-layer clad material instead of batch type, the titanium thin plate conveyed afterwards to the rear end portion of the titanium thin plate conveyed in advance (hereinafter referred to as the preceding titanium thin plate). The front ends of the titanium thin plates (hereinafter referred to as the subsequent titanium thin plate) are connected, and the two titanium thin plates are integrated. The three-layer clad material is produced by clad the continuously connected stainless steel thin plates in the same manner as the continuously connected titanium thin plates, and the obtained three-layer clad material is wound up on a roll.

  Examples of a method for connecting the preceding titanium thin plate (or the preceding metal thin plate) and the succeeding titanium thin plate (or the following metal thin plate) include the following.

  (1) The end portions of the preceding metal thin plate and the succeeding metal thin plate are simply overlapped, and the overlapped portion is connected using a technique such as spot welding or brazing (see, for example, Patent Documents 1 and 2).

  (2) The end portions of the preceding metal thin plate and the succeeding metal thin plate are simply overlapped, and the overlapped portion is mechanically connected by a pin member or the like (see, for example, Patent Document 3). For example, as shown in FIG. 5 (a), a hole 52 is formed at the end of one thin metal plate 51 (right side in FIG. 5), and a taper is formed at the other end (left side in FIG. 5) of thin metal plate 53. The nail | claw part 54 is formed previously. After that, as shown in FIG. 5B, after inserting each claw portion 54 into each hole 52, the tip of each claw portion 54 is folded back and connected.

  (3) The end portions of the preceding metal thin plate and the succeeding metal thin plate are butted, and the butted portions are connected by TIG welding.

Japanese Patent Laid-Open No. 4-89179 JP-A-9-206803 JP 59-141302 A

  However, when the end portions of the preceding titanium thin plate and the subsequent titanium thin plate are connected using the methods (1) and (3) described above, the welded portion and the brazed portion are temporarily in a high temperature state. As a result, the hardness of the titanium thin plate as the base material becomes extremely high and becomes brittle in the welded part and the brazed part. As a result, when deformation such as bending or twisting is applied to the welded part or the brazed part, there is a risk of breakage.

  In addition, when the ends of the preceding titanium thin plate and the subsequent titanium thin plate are connected using the method (2) described above, the connection may be disconnected if deformation such as bending or twisting is applied to the connecting portion. There was a problem that the reliability of the connecting portion was low.

  The purpose of the present invention created in view of the above circumstances is to use a titanium thin plate connecting method that does not cause breakage even if stress associated with deformation such as bending or twisting is applied to the connecting portion, and using the same. It is to provide a connected connecting member.

  In order to achieve the above-mentioned object, the titanium thin plate connecting method according to the present invention is a method of butt-connecting the ends of the titanium thin plates, so as to cover the butted portions of the ends of the titanium thin plates. A non-titanium thin plate is laminated on both surfaces to form a laminated portion, and spot welding is performed with a predetermined interval provided between the laminated portions.

  The thickness of the titanium thin plate is preferably 0.01 to 0.5 mm.

  The non-titanium thin plate preferably has the same thickness as the titanium thin plate, Vickers hardness of 80 to 120 Hv, and elongation of 30 to 50%.

  The non-titanium thin plate is preferably made of a Ni thin plate and has a thickness of 0.1 to less than 0.5 mm (excluding 0.1 mm).

  The welding current during spot welding is preferably 20 to 25 A, and the number of cycles is preferably 20 to 60 cycles / s.

  On the other hand, the connection member of the titanium thin plate according to the present invention is a connection member in which the ends of the titanium thin plates are butt-connected to each other so as to cover the abutting portions of the ends of the titanium thin plates on both surfaces of the titanium thin plates. A laminated portion is formed by stacking titanium thin plates, spot welding is performed at a predetermined interval in the laminated portion, and a titanium thin plate and a non-titanium thin plate are melted and integrated at each spot welded portion.

  According to the titanium thin plate connection method of the present invention, even if a stress associated with deformation such as bending or torsion is applied to the connection portion after connection, an excellent effect is obtained that there is no possibility of breakage.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, a preferred embodiment of the invention will be described with reference to the accompanying drawings.

  A method for connecting ends of titanium thin plates according to a preferred embodiment of the present invention will be described with reference to FIGS. 1, 2 (a), and 2 (b).

  As shown in FIG. 1, first, the titanium thin plates 11 a and 11 b are connected to each other so that the ends of the titanium thin plates 11 a and 11 b are abutted with each other and the abutting portion 12 is covered. The laminated portion 15 is formed by superimposing the non-titanium thin plates 13a and 13b on the both surfaces.

  Next, as shown in FIG. 2A, spot welding is performed at a predetermined interval in the laminated portion 15. Reference numeral 16 in FIG. 2A denotes a spot welding spot. At this time, as shown in FIG. 3, the spot welding interval in the width direction (vertical direction in FIG. 3) of the titanium thin plates 11a and 11b is P1, and the longitudinal direction of the titanium thin plates 11a and 11b (horizontal direction in FIG. 3). The spot welding interval is P2, and the center position deviation of the spot welded portion 16 adjacent in the longitudinal direction of the titanium thin plates 11a and 11b is P3, preferably P3 = (P1 / 2). For example, when the thickness of the titanium thin plates 11a and 11b and the non-titanium thin plates 13a and 13b is less than 0.1 to 0.5 mm (excluding 0.1 mm), P1 and P2 are 15 to 30 mm, and P3 is 7 to 20 mm. A sufficiently large pitch interval is taken.

  By this spot welding, as shown in FIG. 2 (b), the portions sandwiched between the welding electrodes 21a and 21b (shaded portions 22 in FIG. 2 (b)) are respectively heated to a high temperature. Thereby, each shaded portion 22 is partially melted, and the non-titanium thin plates 13a and 13b and the titanium thin plate 11b (or 11a) are integrated. On the other hand, portions other than the shaded portion 22 (non-spot welded portions) are not partially melted, and the non-titanium thin plates 13a and 13b and the titanium thin plate 11b (or 11a) are held in a stacked state. That is, in the intermediate layer (layer of the titanium thin plates 11a and 11b) of the laminated portion 15, the titanium thin plate connecting member in which the island-like titanium thin plates 23 are dispersedly arranged at predetermined intervals in the horizontal direction (direction orthogonal to the lamination direction). Is obtained.

  By using the titanium thin plate connection method according to the present embodiment, a long connecting member is obtained by sequentially repeating the connection between the titanium thin plates, and the long connecting member is appropriately wound around a winding roll or the like. It is wound up on the take-up means. When this connection member is actually used as a product, each stacked portion 15 is not used as a product, and after the stacked portions 15 are cut and removed, the remaining portions are used as products.

  The titanium thin plates 11a and 11b are very thin and have a thickness of 0.01 to 0.5 mm, preferably 0.1 to 0.3 mm. The non-titanium thin plates 13a and 13b are approximately the same thickness as the titanium thin plates 11a and 11b, have a Vickers hardness of 80 to 120 Hv and an elongation of 30 to 50%. For example, as the non-titanium thin plates 13a and 13b, a Ni thin plate, an Fe thin plate, a stainless steel thin plate, or the like having a plate thickness of 0.1 to less than 0.5 mm (excluding 0.1 mm), preferably 0.15 to 0.4 mm may be used.

  Further, the corner portion 41 of the non-titanium thin plate 13a (or 13b) shown in FIG. 4 (a) is, as shown in FIG. 4 (b), a corner portion 42 that is chamfered so that the corner has an R shape, As shown in FIG. 4C, the corner 43 may be chamfered so that the corner has a pointed shape. By chamfering the corner 41 of the non-titanium thin plate 13a (or 13b), damage to the titanium thin plates 11a and 11b due to burrs can be prevented.

  P1 to P3 are appropriately selected according to the thickness of the laminated portion 15 (that is, the thickness of the non-titanium thin plates 13a and 13b), and are large when the laminated portion 15 is thick and small when it is thin. P1 to P3 are appropriately selected according to the hardness and elongation of the non-titanium thin plates 13a and 13b. The hardness of the non-titanium thin plates 13a and 13b is large when the non-titanium thin plates 13a and 13b are high, and small when the non-titanium thin plates 13a and 13b are low. The elongation is small when it is high and large when it is low.

  The welding current during spot welding is 20 to 25 A, preferably around 22 A, and the number of cycles is 20 to 60 cycles / s, preferably 25 to 55 cycles / s, more preferably 35 to 55 cycles / s. The welding current is appropriately selected according to the thickness of the laminated portion 15 (that is, the thickness of the non-titanium thin plates 13a and 13b), and is large when the laminated portion 15 is thick and small when the thin portion is thin. Further, the number of cycles is appropriately selected according to the thickness of the stacked portion 15, and is increased when the stacked portion 15 is thick and decreased when it is thin.

  Next, the effect | action of the connection member produced using the connection method of the titanium thin plate which concerns on this Embodiment is demonstrated.

  In the laminated part 15, since each spot welding part 16 becomes high temperature at the time of welding, those parts are hardened and it becomes weak. Therefore, when the pitch interval of the spot welded portions 16 is too narrow, that is, when the average density of the spot welded portions 16 (the number of spot welded portions / the area of the laminated portions) is high, the entire welded portion (the laminated portion 15 after welding) When stress associated with bending deformation or torsional deformation (tensile stress or compressive stress (hereinafter referred to as bending stress)) is applied, there is a risk of fracture. Therefore, in the titanium thin plate connection method according to the present embodiment, spot welding is performed at a sufficiently large pitch interval with respect to the thickness of the titanium thin plates 11a and 11b and the non-titanium thin plates 13a and 13b. The average density of the spot welds 16 is lowered.

  Further, when a bending stress acts on the welded portion of the connecting member, each spot welded portion 16 in the welded portion is hard and brittle, and thus breaks as it is. Therefore, the non-spot welded portion in the welded portion is required to absorb and relax this bending stress. For this reason, in the titanium thin plate connection method according to the present embodiment, soft and good stretched materials are used as the non-titanium thin plates 13a and 13b. Specifically, non-titanium thin plates 13a and 13b having the same thickness as the titanium thin plates 11a and 11b, Vickers hardness of 80 to 120 Hv, and elongation of 30 to 50% are used.

  As a result, even if bending stress is applied to the welded portion of the connection member, bending stress is absorbed and relaxed in the non-spot welded portion, so that there is almost no possibility that the bending stress is applied to the spot welded portion 16. On the other hand, when an external force such as an impact is applied to the welded portion of the connection member, if the external force is small, the non-titanium thin plates 13a and 13b completely absorb and relax the external force. Moreover, when a deformation | transformation arises with the big external force in the welding part of a connection member, since a non-spot welding part deform | transforms first, there is almost no possibility that a deformation | transformation will arise in each spot welding part 16. FIG. Therefore, even if bending stress or external force is applied to the welded portion of the connecting member, there is no possibility that the welded portion of the connecting member will break.

  The connection member produced using the titanium thin plate connection method according to the present embodiment is not particularly limited in its use, but is suitable as, for example, a Ti material of a three-layer clad material constituting a fuel cell. .

  As described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various other things are assumed.

  Next, although this invention is demonstrated based on an Example, this invention is not limited to this Example.

(Test 1)
The end portions of the 0.3 mm thick titanium thin plate were butted together, and a 0.1 mm thick nickel thin plate (non-titanium thin plate) was laminated on both sides of the titanium thin plate so as to cover the butted portion to form a laminated portion. Spot welding was performed at a predetermined interval in the laminated portion to produce a connection member (Sample 1). The spot welder (YR-150SRF, manufactured by Matsushita Electric Industrial Co., Ltd.) used for spot welding has a rated minimum capacity of 15kVA, a rated primary voltage of 200V, a maximum applied pressure of 150kgf, a rated frequency of 50Hz, and a maximum short-circuit current. It was 11kVA and the allowable usage rate was 9%. Spot welding conditions (welding current (A) × cycle (s)) were 22 × 30, 22 × 40, 22 × 50, 27.5 × 30, 27.5 × 40, and 27.5 × 50. The welding current here is a calculated value obtained by multiplying the value obtained by dividing the maximum short-circuit current by the maximum scale by the actual measurement scale.

(Test 2)
A connecting member was prepared in the same manner as in Test 1 except that the thickness of the nickel thin plate was 0.15 mm (Sample 2). Spot welding conditions (welding current (A) × cycle (s)) were 22 × 30, 22 × 40, and 22 × 50.

(Test 3)
A connecting member was prepared in the same manner as in Test 1 except that the thickness of the nickel thin plate was 0.2 mm (Sample 3). Spot welding conditions (welding current (A) × cycle (s)) were 22 × 30, 22 × 40, and 22 × 50.

(Test 4)
A connecting member was prepared in the same manner as in Test 1 except that the thickness of the nickel thin plate was 0.3 mm (Sample 4). Spot welding conditions (welding current (A) × cycle (s)) were set to 22 × 40 and 22 × 50.

(Test 5)
A connecting member was prepared in the same manner as in Test 1 except that the thickness of the nickel thin plate was 0.4 mm (Sample 5). Spot welding conditions (welding current (A) × cycle (s)) were set to 22 × 50 and 27.5 × 50.

(Test 6)
A connecting member was prepared in the same manner as in Test 1 except that the thickness of the nickel thin plate was 0.5 mm (Sample 6). Spot welding conditions (welding current (A) × cycle (s)) were 27.5 × 50 and 27.5 × 55.

(Test 7)
A connecting member was prepared in the same manner as in Test 1 except that the thickness of the nickel thin plate was 0.8 mm (Sample 7). Spot welding conditions (welding current (A) × cycle (s)) were set to 33 × 55.

  About samples 1-7, weldability, bondability, and comprehensive evaluation were performed. The evaluation results are shown in Table 1.

  Here, the evaluation of the bondability is such that when tensile stress such as bending or twisting is applied, peeling does not occur in the welded portion (laminated portion after welding), and fracture occurs in a portion other than the welded portion. The case where the part which did not peel off at the welded part and the part where the peeled off coexisted was marked with ○, and the part where the welded part could be easily peeled by hand was marked with ×. On the other hand, in the comprehensive evaluation, “Excellent” indicates “Good”, “Good” indicates “Good”, and “Poor” indicates “Poor”.

  As shown in Table 1, in Sample 1, since the thickness of the nickel thin plate was too thin, almost all spot welds had holes, and spot welding could not be performed satisfactorily. Naturally, since the welded part was not joined, it was easily peeled off by hand, and the joining property was x. From the above, the overall evaluation was x.

  Sample 2 had a hole in the spot weld, but the weldability was almost good. Moreover, although there was a part which was not joined partially in a welding part, joining property was (circle). From the above, the overall evaluation was ○.

  Sample 3 had no hole in the spot welded portion and had good weldability. Moreover, although there was a part peeled off at a part of the welded portion, the bondability was good. From the above, the overall evaluation was ○. Among them, those with spot welding conditions of 22 × 40 and 22 × 50 had no part peeled off at the welded portion (joinability was ◎), and the overall evaluation was ◎.

  Samples 4 and 5 had no hole in the spot welded portion and had good weldability. Moreover, although the strength of the welded part was slightly insufficient with respect to bending and twisting, the strength against tension was sufficient and the bondability was good. From the above, the overall evaluation was ○.

  In Samples 6 and 7, spot welding itself could not be performed because the nickel thin plate was too thick. Naturally, since the welded part was not joined, it was easily peeled off by hand, and the joining property was x. From the above, the overall evaluation was x.

  For Samples 2-5, a test of running an actual line (continuous annealing line, clad mill line) was performed, but no breakage occurred in the welded portion of the connecting member, and there was no practical problem at all. It was.

It is a figure for demonstrating the connection method of the edge parts of the titanium thin plate which concerns on preferable one Embodiment of this invention. It is a figure for demonstrating the spot welding in a laminated part. 2A is a cross-sectional view showing a state before spot welding, and FIG. 2B is a cross-sectional view showing a state during spot welding. It is a top view of the lamination part vicinity. It is a top view of a non-titanium thin plate. 4A is an overall view, and FIGS. 4B and 4C are enlarged views of the corners of FIG. 4A. It is a figure for demonstrating the connection method of the edge parts of the titanium thin plate in the past.

Explanation of symbols

11a, 11b Titanium thin plate 12 Butt portion 13a, 13b Non-titanium thin plate 15 Laminated portion

Claims (6)

  In the method of butt-connecting the ends of the titanium thin plates, a non-titanium thin plate is stacked on both surfaces of the titanium thin plates so as to cover the butted portions of the titanium thin plates, and the stacked portion A method for connecting titanium thin plates, wherein spot welding is performed at a predetermined interval.   The titanium thin plate connection method according to claim 1, wherein the titanium thin plate has a thickness of 0.01 to 0.5 mm.   The method for connecting titanium thin plates according to claim 1 or 2, wherein the non-titanium thin plate has the same thickness as the titanium thin plate, has a Vickers hardness of 80 to 120 Hv, and an elongation of 30 to 50%.   The method for connecting titanium thin plates according to any one of claims 1 to 3, wherein the non-titanium thin plate is composed of a Ni thin plate and has a thickness of 0.1 to less than 0.5 mm (excluding 0.1 mm).   The method for connecting titanium thin plates according to any one of claims 1 to 4, wherein a welding current at the time of spot welding is 20 to 25 A and a cycle number is 20 to 60 cycles / s. In the connecting member in which the ends of the titanium thin plates are butt-connected, the non-titanium thin plates are laminated on both surfaces of the titanium thin plates so as to cover the butted portions of the ends of the titanium thin plates, and the lamination A titanium thin plate connecting member characterized in that spot welding is performed with a predetermined interval in each portion, and a titanium thin plate and a non-titanium thin plate are fused and integrated at each spot weld portion.

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