JPH0215307B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for laminating and joining dissimilar metal plates that are difficult to weld together.

(Prior Art) In chemical plants, etc., in order to improve the corrosion resistance of equipment made of metal materials, for example, the inner surface of a chemical reaction vessel is made of a highly corrosion-resistant metal material that cannot be welded to the metal plate material that makes up the vessel. However, in laminated joining of dissimilar metal plates that cannot be welded, a bolt is inserted through the two metal plates, tightened with a nut, and then the head of the bolt is covered with one of the metal plates and the same material. Generally, a method is adopted in which the material is covered with a plate and its peripheral edge is welded to one metal plate. However, with this method, since bolt holes are provided that communicate with both metal plates, if there is a slight welding defect in the welded area on the periphery of the cover plate, the inside and outside will communicate through the bolt holes, causing chemical damage. It is not suitable for reaction vessels or hazardous materials storage containers, and
The cover plate that covers the bolt head swells up, creating a raised shape in some places on the plate surface, and when it comes into contact with fluid, turbulence occurs in these areas, which can cause cavitation and reduce corrosion resistance. Therefore, Tokukai Sho
A dissimilar metal layer bonding method as shown in No. 59-229293 has also been proposed. The invention described in this publication is
When joining two dissimilar metal plates that cannot be welded together by providing a clearance between them, an insert piece is sandwiched between the two dissimilar metal plates, and the dissimilar metals are solid-state welded to the corresponding metal of the insert piece. Dissimilar metal plates are joined by welding the dissimilar metal plates, but in the method described above, insert chips are produced in large quantities by solid-phase welding the opposing joint surfaces of dissimilar metal chips. In addition to the problem of having to keep the insert chips of the desired combination of dissimilar metals on hand, there is also the problem of having to always have insert chips with the desired combination of dissimilar metals available, which makes us hesitant to use them for simple construction. Furthermore, a clearance inevitably occurs between dissimilar metal plates.

(Problems to be Solved by the Invention) The problems to be solved by the present invention are to solve the problems of the conventional methods as described above, and to have safety that satisfies safety standards such as the Fire Service Act. The object of the present invention is to provide a method for laminating and joining dissimilar metal plates that is easy to construct and can be applied to combinations of various metals.

(Means for Solving the Problems) The present invention provides a method in which a stopper is placed in a fitting hole in the other metal plate which cannot be welded to the metal plate overlapped with the other metal plate, and The outward bent part of the tip of the clasp welded to the clasp and fitted into the clasp fitting hole is engaged with the hole edge of the clasp fitting hole to join the other metal plate to the one metal plate. and then covering the clasp fitting hole and the clasp with a cover plate piece made of the same material as the other metal plate material, and welding the peripheral edge of the cover plate piece to the other metal plate material. It is something to do.

In the present invention, when laminating and joining different types of metal plates that cannot be welded, one metal plate that serves as a base material, a clasp that can be welded to the metal plate, and a metal that cannot be welded to the one metal plate. The other metal plate is provided with a clasp fitting hole large enough to fit the clasp at the required location, and is made of a metal that can be welded to the metal plate and is sufficient to cover the clasp fitting hole. A clasp whose base is welded to one metal plate is fitted into the clasp fitting hole of the other metal plate overlaid on one metal plate, and a first step of bonding and holding the other metal plate to one metal plate with an outwardly bent portion that protrudes from the surface of the metal plate and engages with the hole edge of the clasp fitting hole; The fitting hole and the stopper with the outward bent part fitted into the fitting hole are covered with a cover plate piece of the same type as the other metal plate material whose peripheral edge is welded to the other metal plate material, so that there is almost no bulge. This process consists of a second process of forming an inner lining surface. In addition, in the first step, a short tubular clasp is welded to one of the metal plates in advance, and the other metal plate having a clasp fitting hole corresponding to the clasp is attached to the clasp. An outward bent part that is overlapped with one metal plate while engaging with the clasp fitting hole, and the protruding tip of the short tubular clasp is enlarged in diameter to engage the edge of the clasp fitting hole. However, in cases where the clasp is in the shape of a cap with a flange, the two metal plates are overlapped, the clasp is fitted into the clasp fitting hole, and the bottom of the clasp is formed on one side. The clasp may also be spot welded to a metal plate, and the clasp does not necessarily have to be cylindrical, and the outwardly bent portion may also be a plurality of claw-like pieces instead of a series of flange-like pieces.
Furthermore, although the material of the clasp is generally the same as that of one metal plate, it may be made of a different metal as long as it can be welded.

(Example) When manufacturing a tank for combustible materials made of iron plate lined with titanium alloy plate, the base material was 3 mm thick.
The tank body is made using one of the iron plates as metal plate material 1, and the inner surface is 20 mm in diameter and 10 mm in length at 40 cm intervals.
A short pipe was welded as the clasp 2. Next, the wall thickness is 1mm.
A titanium alloy plate is prepared as the other metal plate material 3, and clasp fitting holes 4 with a diameter of 22 mm are provided at intervals of 40 cm, and this other metal plate material 3 is inserted into the clasp fitting holes 4.
After the clasp 2 is fitted onto the inner surface of one of the metal plates 1, the diameter of the protruding end of the clasp 2 is expanded to form an inward bent portion 5 in each clasp fitting hole 4. It was fixed to the edge of the hole. Next, prepare a large number of circular cover plate pieces 6 made of titanium alloy plates with a wall thickness of 1 mm and a diameter of 7 cm, and place them so that each clasp fitting hole 4 and the inwardly bent portion 5 of the clasp 2 are covered. on the inner surface of the other metal plate 3, and align the periphery of each cover plate piece 6 with the other metal plate 3.
It was welded into a product.

The product obtained in this way has no holes such as bolt insertion holes in one metal plate 1, so there is no risk of the fluid stored in the tank leaking out to the outside, and it is extremely safe and meets safety standards. Although the base material was iron, the inner lining was a titanium alloy plate, so it was fully satisfactory in terms of both structural strength and corrosion resistance. Moreover, since the cover plate piece 6 also protrudes only slightly from the other metal plate material 3, the appearance is good and there is no inconvenience in terms of cleaning and other maintenance.

(Effects of the Invention) As is clear from the above description, the present invention allows dissimilar metal plates that cannot be welded to be laminated and joined accurately and easily, and the joint portion does not bulge out.
In the conventional method, insert chips made by solid phase bonding of dissimilar metal chips must be mass-produced, and insert chips made by combining dissimilar metal plates in desired combinations must always be produced. There are no problems such as having to open the hole or creating a clearance between different metal plates, and compared to a method in which the perforated plate is tightened with bolts and the tightening structure is covered with the same type of metal plate and welded, The protrusion of the joint structure is extremely low,
The degree to which turbulent flow occurs in this portion, causing cavitation and reducing corrosion resistance, is greatly reduced.The present invention, which has such advantages, greatly contributes to the development of industry.

[Brief explanation of drawings]

The drawing is a cross-sectional view of a main part showing an example of a dissimilar metal laminate obtained by the method of the present invention. 1: one metal plate material, 2: clasp, 3: other metal plate material, 4: clasp fitting hole, 5: inward bent part,
6: Covering board piece.

Claims (1)

[Claims] 1. A metal plate that is overlapped with one metal plate has a stopper fitting hole arranged in the other metal plate that cannot be welded, and a metal plate that is welded to one metal plate fits into the stopper fitting hole. The outward bent portion of the tip of the fitted clasp is engaged with the hole edge of the clasp fitting hole to bond and hold the other metal plate to one metal plate, and then the same metal plate as the other metal plate is attached. 1. A method for laminating and joining dissimilar metal plates, characterized in that the clasp fitting hole and the clasp are covered with a cover plate piece of the metal material, and the peripheral edge of the cover plate piece is welded to the other metal plate material.