JPS6068190A - Cored wire for welding - Google Patents

Abstract

PURPOSE:To perform inexpensive build-up operation with high efficiency by filling a filler contg. nickel powder in a hoop consisting of a cuprous material thereby forming a cored wire for welding. CONSTITUTION:A material for forming a hoop 1 is enumerated by electric, copper, oxygen-free copper, deoxidized copper, etc. A filler 2 is a mixture composed of nickel powder and copper powder having preferably a fine grain size. DC arc welding is executed in an inert gaseous atmosphere of argon or the like by using the above-mentioned cored wire. The arc itself spreads and consequently the bead having a shallow penetration depth and a broad width is obtd. The rate of dilution in the molten metal part is therefore smaller and even if a member to be subjected to build-up welding is subjected directly to build-up welding without providing an intermediate layer such as nickel or monel metal, the defectless molten part having no weld defect such as cracking or the like is obtd.

Description

[Detailed description of the invention] This invention relates to a composite wire for welding.

Conventionally, overlay welding of cupronickel, a copper alloy containing approximately 10 to 30% nickel, has been performed on the inside of desalination equipment and the like in order to improve its corrosion resistance. In this case, in order to prevent the occurrence of cracks in the overlay welding part and maintain corrosion resistance, an intermediate layer of nickel or monel is first formed on the surface of the overlay part, and then an actual cupronickel layer is applied on top of the intermediate layer of nickel or monel. It is common to perform low current pulsed welding using wire. However, the method described above has the disadvantage that it requires the use of expensive materials and a lot of labor to form the intermediate layer, resulting in a large construction cost. In addition, the actual cupronickel wire is
When manufacturing it, it is necessary to melt cupronickel and then wire-draw it, which makes it expensive, which is also one of the reasons for the increase in construction costs. Furthermore, the purpose of using a low current pulsed arc as described above is to reduce the penetration depth and the dilution rate of the molten metal. Since it is necessary to use the machine, its working efficiency is not necessarily satisfactory.

This invention was made in view of the above, and its purpose is to directly overlay cupronickel on the surface of the overlay workpiece without providing an intermediate layer, since the penetration depth can be reduced. To provide a composite wire for welding which can be manufactured at low cost.

The composite welding welding band of the present invention, which meets the above object, has a hoop made of a copper-based material, and a filler containing nickel powder is filled in the hoop.

As mentioned above, the hoop and the filler are made of different materials,
Since cupronickel can be obtained in a molten and mixed state of both, commercially available materials can be used for the hoop and the filler, making it possible to manufacture composite wire for welding at low cost. It becomes possible. Moreover, when welding is performed using the composite wire as described above, the arc always occurs at the tip of the hoop, so the arc spreads out as a whole compared to when using solid wire, and as a result, the welding depth is shallower. It becomes possible to obtain a wide bead. Therefore, the dilution ratio in the molten metal is small, and even if weld directly to the surface of the part to be overlaid without providing an intermediate layer such as nickel or Monel, a healthy welded metal part without welding defects such as cracks can be obtained. It becomes possible to obtain.

Next, specific embodiments of the present invention will be described in detail with reference to the drawings.

In the figure, 1 indicates a hoop, and 2 indicates a filler. In this case, the hoop 1 is shown to have an annular cross section, which is the simplest shape, but the shape is of course not limited to this shape in practice.

Materials for forming the hoop 1 include electrolytic copper, oxygen-free copper,
Examples include deoxidizing steel, but in some cases copper alloys containing other alloying elements may be used.

Further, it is preferable to use the hoop 1 having a thickness of about 0.4 mm when the wire diameter is 1.6 mm, but it is of course possible to use other dimensions. The filler 2 is a mixture of nickel powder and copper powder, both of which have a particle size of 32 mesosites (JIs) or less. The reason why the grain size is preferably fine is that when the hoop 1 is filled with the filler 2 and further wire drawing is performed, the filler 2 prevents the hoop 1 from being smoothly stretched and deforms. This is to prevent In addition, the above-mentioned filler 2
Some may contain other alloying elements (for example, small amounts of iron) or fluxes such as arc stabilizers. The ratio of nickel and copper in the composite wire is varied, for example, to 90% copper and 10% nickel, or 70% copper and 30% nickel, depending on the type of cupronickel required.

Direct current arc welding is performed using the above-mentioned composite wire in an inert gas atmosphere such as argon.
Since welding is performed using a composite wire, the arc itself spreads, and as a result, it is possible to obtain a shallow weld depth and a wide bead.

Therefore, the dilution rate in the molten metal part becomes smaller,
It was possible to obtain a sound molten metal part without weld defects such as cracks even when overlay welding was performed directly on the surface of a member to be overlaid such as mild steel without providing an intermediate layer such as nickel or monel. Moreover, since welding can be performed with a higher arc current (200 to 27 OA) than conventional pulsed arc welding (160 to 180 A), the work efficiency can be greatly improved.

The composite wire for welding of the present invention is constructed as described above. Therefore, the composite wire for welding of the present invention makes it possible to perform overlay work at low cost and with high efficiency. It also becomes possible to provide the product at a low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the welding composite wire of the present invention. 1... Hoop, 2... Filler. Patent applicant Sumikin Welding Rod Co., Ltd.

Claims (1)

[Claims] 1. A hoop is formed from a copper-based material, and 2.
A composite wire for welding made of a filler containing Kel powder.