JP2000135574A - Foreign material joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of peeling-off and separation during welding and in a cooling process after welding by providing a male-female shape of convex and concave parts on a jointing face of two structural members, engaging each convex part in the corresponding concave part, physically jointing both parts, and also metallurgically jointing at least one part of the jointing face. SOLUTION: For example, five lines of convex and concave parts 3 with 4 mm height composed of a trapezoidal shape whose one corner is about 60 degrees, are formed in a length direction on the jointed face of a stainless steel to be a second structural member 2 by machining. Then, an aluminum material to be a first structural member 1 is melted, and the molten metal is poured into the surface of the convex and concave portion 3, cooled and solidified, so that engage jointing is physically performed. Furthermore, a jointing face 7 in parallel to a jointing face of the first structural member 1 and the second structural member 2 is metallurgically jointed by dispersion jointing. When a fillet welding part 6 is formed with the same materials on each side of the obtained foreign material joint 8, peeling-off or separation does not occur to the convex and concave part 3 during and after welding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dissimilar material joint made of a composite material for connecting structural materials or structures made of dissimilar metal materials.

[0002]

2. Description of the Related Art As a conventional dissimilar material joint, when connecting aluminum and stainless steel as structural materials, for example, a joint material made of explosive composite material made of aluminum, nickel, titanium, and stainless steel is used. Welded and connected. In Japanese Patent Application Laid-Open No. H10-185040, for example, in a flange structure, a joint material having unevenness perpendicular to a joining surface of a high-temperature pressure joining composite material made of aluminum and stainless steel is used to weld aluminum to each other or stainless steel to each other. Was done and connected.

[0003] However, in the conventional explosion-bonded composite material, nickel and titanium are inserted as intermediate materials in order to improve the joining strength. Because of the cost, the production cost is high. On the other hand, in Japanese Patent Application Laid-Open No. Hei 10-185040, the intermediate material is not required, so that it can be manufactured at a low cost. Are bonded by a step perpendicular to the joint surface. However, as described in the section of the prior art, since the strength of the joint surface is generally not so high in direct joining, the dissimilar material of the Separation was observed even after welding the actual joint, that is, peeling occurred at the joint surface during the cooling process after welding, and peeling and separation occurred during actual use after welding. In addition, work such as replacement is required, and many man-hours and costs have been incurred.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a dissimilar joint in which dissimilar joints are inexpensive and in which there is no separation or separation during the cooling process after welding and during actual use after welding. Aim.

[0005]

In order to solve the above-mentioned problems, the present inventor has made various studies on the prevention of peeling of a dissimilar joint material which does not require an intermediate material in order to reduce the cost. When the material is expanded, the pressing force acts in the direction perpendicular to the joint surface, so there is no problem.However, the joint strength decreases due to the contraction stress in the direction perpendicular to the joint surface during the solidification process during cooling after welding. The present invention has been found to cause peeling or peeling or separation and has led to the present invention.

According to the present invention, the joint surface is provided with an indented shape so that the joint surface can sufficiently resist shrinkage stress in the direction perpendicular to the joint surface generated during the solidification process during welding of dissimilar materials.
Each convex part is fitted into the corresponding concave part, and physically fitted and joined so that vertical detachment does not occur, and at least a part of the joint surface is metallurgically joined by high-temperature pressure joining method etc. The present invention relates to a dissimilar material joint configured to be a strength member made of a dissimilar metal.

Hereinafter, the present invention will be described in detail. The unevenness of the joint surface is a polyhedral shape, a spherical shape, or a polygonal column shape in which the convex portion of the first structural member or the second structural member is fitted into the concave portion of the second structural member or the first structural member, respectively. Or a combination of these shapes or a combination of these shapes. The shape is not particularly limited as long as it is a shape that does not easily peel or separate in the direction perpendicular to the joint surface and that physically fits. Although not preferred, a trapezoidal shape is preferable in practice. For example, as shown in FIG. 1, on the joint surface 7 between the first structural member and the second structural member, the convex portion has a longer top side than the bottom side, and the concave portion has A trapezoidal irregularity in which the bottom of the inverse similar shape is longer than the top is provided. FIG. 2 shows an example in which unevenness having a shape using both a trapezoidal shape and a cylindrical shape is provided.

Although the number of unevenness may be one, it is effective to use a plurality depending on the use of the joint material to be used. In the case of pillar-shaped unevenness, the direction of the axis of the pillar may be provided in a row as one direction, or may be provided in a direction intersecting the same, and may be in a grid shape. The length of the unevenness may extend over the entire length of the joint surface, or may be interrupted in the middle.

[0009] The irregularities may be formed by machining, extrusion, or casting. In the concave and convex portions of the two metal materials, the metal materials are simply inserted or one of the metal materials having a low melting point is melted and poured into one of the metal materials having a concave portion having a high melting point, and cooled and solidified to be physically fitted and joined. A part of the joint surface is further metallurgically joined.
Preferably, the flat portion of the uneven portion parallel to the bonding surface is metallurgically bonded. Metallurgical bonding is achieved by explosive bonding, diffusion bonding, hot pressing (HIP) or roll bonding.

[0010] The relationship between the shape of the dissimilar material joint and the means for physically fitting may be freely selected and is not limited. However, when the irregularities are polyhedral or spherical, one metal is melted and poured into the concave portion and cooled. It is effective to solidify and physically fit and join. As a combination of metal materials for which the present invention is particularly effective, there is a concern that peeling or separation may occur due to thermal expansion of welding heat and contraction stress at the time of cooling. Combinations of steel or stainless steel.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment will be described.

[0012]

Embodiment 1 A stainless steel JIS-G-H4304 SUS304L joining surface, which is to be the second structural member 2 shown in FIG. 3, is machined into a trapezoidal shape having a corner of 60 degrees and a height of 4 mm. The irregularities 3 are formed in five rows in the length direction, and the aluminum JIS-H-4000 A1050P serving as the first structural member 1 is melted, and a molten metal is poured into the surface of the irregularities 3 to be cooled and solidified to physically fit. Bonding was performed, and furthermore, the flat portion 7 parallel to the bonding surface between the first structural member and the second structural member 2 was metallurgically bonded by diffusion bonding. The size of the obtained dissimilar material joint is 80 mm in width and 20 in length.
0 mm, and the thickness is 2 in the first structural member 1 above the unevenness 3.
The thickness of the second structural member 2 on the lower side of 0 mm was 30 mm. In order to perform cruciform welding, the same material as the first structural member 1 is formed on the surface of the first structural member 1 with a thickness of 15 mm, a height of 150 mm, and a length of 20 mm.
A 0 mm joint material A4 aluminum plate and the back surface of the second structural member 2 have a thickness of 8 mm made of the same material as the second structural member 2.
Fillet welding 6 was performed using a B5 stainless steel plate having a joint material of 150 mm in height and 200 mm in length.

As a result, no peeling or separation was observed on the irregularities 3 during and after welding. Further, a cross tension test was also performed after welding with the original size, but the aluminum of the joint A4 was broken, and no peeling or separation was observed on the irregularities 3.

[0014]

Comparative Example 1 As shown in FIG. 4, cross fillet welding 6 was carried out in the same manner as in FIG. The materials used were the same as those in Example 1, and the dimensions were the same as the width of 80 mm and the length of 200 mm in order to make the same thermal effect by welding. Although the step perpendicular to the joining surface 7 is 10 mm, the thickness of the central convex portion 60 mm in which the fillet is welded is 20 mm for the first structural member 1 aluminum and the second structural member 2 stainless steel central concave step. The welding was performed under the same conditions as in Example 1 except that the portion was the same as 30 mm.

As a result, the joint material A
A gap of 1 mm and a length of 10 m at a portion of the joint surface 7 almost directly below
m was observed. Further, when a cross tension test was performed with the original size in the same manner as in Example 1, the first structural member 1 and the second structural member 2 were completely separated and separated from the separation portion as a starting point.

[0016]

Since the dissimilar joint of the present invention does not cause any peeling or separation, it can be manufactured at a low cost while ensuring the safety of structural materials and structures. This has the effect of greatly contributing.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of a dissimilar material joint of the present invention.

FIG. 2 is a cross-sectional view of one embodiment of the dissimilar material joint of the present invention.

FIG. 3 is a cross-sectional view of one usage example using the dissimilar material joint of the present invention.

FIG. 4 is a cross-sectional view of a usage example using a conventional dissimilar material joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 1st structural member 2 2nd structural member 3 Irregularity 4 Joint material A5 Joint material B6 Fillet welded part 7 Joining surface 8, 8a Dissimilar material joint

Claims (2)

[Claims] 1. A joint surface of a first structural member made of a first metal material and a joint surface of a second structural member made of a second metal material, each having at least one convex portion and / or concave portion. Having a convex portion or a concave portion of the first structural member, and a convex portion or a concave portion of the second structural member forming a pair with the convex portion or the concave portion, and are physically fitted and joined, and A dissimilar material joint, wherein at least a part of the joint surface is metallurgically joined. 2. The dissimilar joint according to claim 1, wherein said first metal material is aluminum or aluminum alloy, and said second metal material is steel or stainless steel.