JPH01293981A - Welding method for precipitation hardening type copper base alloy - Google Patents

Abstract

PURPOSE:To prevent a weld zone from being softened and to improve working efficiency by surrounding an objective part to be welded and fitting a water- cooling member such as moisture cloth or a conduit pipe thereto to perform welding. CONSTITUTION:The annular conduit pipe 2 is arranged to the surface of a casting mold 1 so as to surround the objective part such as a cracked part A. Flux 4 is then supplied to the weld zone and cooling water is circulated through the conduit pipe 2. Welding torches 3 are disposed to face oppositely above the weld zone and while a gaseous Ar, etc., are discharged from the torch tips, a built-up welding of the title precipitation hardening type copper base alloy is performed on the cracked part A. Since welding is performed while cooling the weld zone and its vicinity, a high-temperature rise of the temperature of the weld zone is prevented. By this method, flocculation and a softening phenomenon of deposited particles of the precipitation hardening type copper base alloy can be prevented. Accordingly, the weld zone is prevented from being softened and the working efficiency of welding is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a method for welding precipitation hardening copper-based alloys, typified by Cu-Be alloys.

<Prior art> Cu-Be alloys containing 3% by weight or less of Be are precipitation hardening alloys, and can be improved by appropriate heat treatment to achieve high strength, excellent elasticity, and
Since it is non-flammable, conductive, wear resistant, and corrosion resistant, it has a wide range of uses including communications equipment, automobiles, and steel manufacturing. In addition, Cu-Co alloys and Cu-Zi containing small amounts of CO and Zi
Gold alloys are also precipitation hardening alloys, and in addition to high strength, they also have magnetic properties and other special properties that Cu does not have, so they have applications that take advantage of these properties.

However, after precipitation hardening, such precipitation hardening alloys have the property that when heated above a certain temperature determined by the composition, the precipitated particles agglomerate and soften, and this softening temperature is 300 It is around °C. For this reason, precipitation hardening alloys cannot be subjected to treatments that involve heating after being subjected to aging treatment for precipitation hardening, and cannot be subjected to welding treatment, which is a typical example of treatments that involve heating.

<Problems to be Solved by the Invention> As mentioned above, when making a product using a precipitation hardening alloy, especially a copper-based alloy with high thermal conductivity, if welding is required, the first step is to weld it. After joining, the whole must be subjected to solution treatment, cooling, and aging treatment, and if the item is large, workability is poor, and some items made from this type of precipitation hardening alloy may Even if a damaged part is partially repaired by overlay welding using the same type of precipitation hardening alloy or a different type of material, there is the complexity of having to perform solution treatment, cooling, and aging treatment again.

The object of the present invention is to eliminate the above-mentioned drawbacks and to provide a welding method in which the hardened properties are not lost even if no solution treatment or age hardening treatment is required after welding.

<Means for Solving the Problems> An object of the present invention is to provide a method for surrounding the welding target part when welding precipitation hardening copper-based alloys together or overlaying another material onto the precipitation-hardening copper-based alloy. This can be achieved by a welding method for precipitation hardening copper-based alloys, which is characterized in that welding is performed with a water-containing fabric or a water-cooling member such as a water guide pipe attached to a solid state.

The welding used in the present invention preferably employs a gas shield welding method.

In the present invention, the area to be welded is surrounded in a relatively narrow area with a water-containing fabric or a water guide pipe, and welding is performed while cooling the area, so that areas other than the welding area are not exposed to high temperatures, so that precipitated particles agglomerate. Or it will never dissolve.

<Examples> The present invention will be described in detail below with reference to drawings showing examples thereof.

Figures 1 and 2 show BeO, 5% by weight-Ni1.8
It is a figure which shows the case where the crack which occurred in the surface of the continuous casting mold 1 made of a helium copper alloy which consists of weight% residual Cu is repaired by overlay welding.

The crack occurrence area A has been pre-processed by grinding or the like, and as shown in FIG.
adheres closely to the surface. Next, as shown in FIG. 2, the welding torches 3 are placed facing each other to perform welding. At this time, cooling water is circulated within the water guide pipe 2 to ensure sufficient cooling, and is applied to the welded area as necessary. Further, He and gauge gas are emitted from the tip of the welding torch to shield the welding area, and a well-known flux 4, which has a large cleaning effect, is supplied to the welding area.

Although parts of the mold 1 other than the welded part are not shown, they may be further cooled by other appropriate means, and if the vicinity of the welded part becomes overheated during welding, welding may be temporarily interrupted and/or In some cases, methods such as quenching separately and continuing welding may be used.

An overlay welding test was conducted on the mold 1 of the above example using a welding rod that produced a deposited metal having the same composition as that of the mold 1, and the results thereof are shown below. That is, as shown in Fig. 3, the thickness of the build-up layer at the center of the weld is about 12 mm, the diameter from the center to the surface is about 25 mm, and the build-up layer has the cross-sectional shape shown in Fig. 3. Overlay welding was performed so that it became thinner toward the periphery, and then about 1 mm of the surface layer was ground away, and the Vickers hardness (UV: 10100O) was measured for each part in the lateral direction. The results are shown in Figure 4. It is a graph.

From the results shown in FIG. 4, it can be seen that the hardness of the heat-affected zone is considerably reduced, but the hardness of other parts is not so reduced.

In addition, the welding defect test was conducted on each part according to JIS-Z 3104, and the overall result was 1st grade.

<Effects of the Invention> As described above, according to the method of the present invention, the vicinity of the welded part is surrounded by a water-cooled member and welding is performed while cooling the welded part, so that the welded part and its surroundings are not exposed to very high temperatures. In addition, since the area outside the mounting part of the water-cooled member is hardly heated at all, the precipitated particles of the precipitation-hardening copper-based alloy rarely aggregate or dissolve (although softening is possible). Even if there is a vibration that is blocked, it is only within a narrow range, so if you look at the object as a whole, it is almost as if it has not softened.

Therefore, there is no need to perform solution treatment, cooling, and aging treatment on the entire assembly after welding, resulting in a significant improvement in work efficiency.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an example of the present invention, Figure 2 is a cross-sectional explanatory view of the same essential parts, Figure 3 is a schematic diagram for explaining the hardness test in the example, and Figure 4 is the hardness test. Graph showing the results. In the figure, 1: Mold 2: Water guide pipe 3; Welding torch 4: Flux A: Crack initiation area Patent applicant: Fujiki Kosan Co., Ltd. Representative Noriharu Ariyoshi (Bo
oot: All)♀gradient'f-4<, 2L
Procedural amendment to Ward+17 (voluntary) ■, Indication of the case 1988 Patent application No. 126082 2, Name of the invention Method for welding precipitation hardening copper-based alloys 3, Person making the amendment Relationship to the case Patent applicant address To Kitakyushu City, 2271 Bold Kishiro, Hasanishi Ward, 2 names: Fujiki Kosan Co., Ltd. Representative: Kimiaki Manabe 4, Agent (1), "Zi" on page 1, line 19 and line 20 of the specification
is corrected to "Zr". =1-

Claims (1)

[Claims] 1. When welding precipitation-hardening copper-based alloys together or overlaying other materials onto precipitation-hardening copper-based alloys, use a water-containing fabric or water guide pipe to surround the welding area. A method for welding precipitation hardening copper-based alloys, characterized by performing welding with a water-cooled member attached.