JPS5938306B2 - Manufacturing method of wire rod for thermal spray coating - Google Patents

Description

[Detailed description of the invention] The present invention relates to a novel method for manufacturing wire rods for thermal spray coating.

Zinc-aluminum alloy wire as wire for thermal spray coating is widely used for corrosion protection of steel towers, bridges, etc. due to its excellent corrosion resistance.

By the way, this type of alloy wire has conventionally been made by hot extrusion or rolling milling, but it is prone to high-temperature brittleness, so it is not possible to increase the degree of processing in one pass, and it is difficult to make the wire thinner. Labor day labor has become extremely inefficient work.

Furthermore, when the degree of working is lowered to avoid high-temperature embrittlement, the deformation resistance of this alloy system rapidly increases, making further processing difficult. Further, depending on the diameter of the product, it may be necessary to perform wire drawing after extrusion or rolling, but for the same reasons as above, this operation is difficult and requires a large amount of means to thin the wire.

Even if it could be processed into wire for thermal spraying, the wire is extremely hard, so it would be difficult to feed the material with the thermal spray gun used for normal zinc thermal spraying, and special thermal spraying equipment would be required.

With conventional zinc-aluminum alloy wire, the melting process is performed twice before the zinc-aluminum alloy is thermally sprayed to form the required spray amount.

The first time is when an alloy ingot, which is the raw material for manufacturing the thermal spray wire, is cast, and the second time is when the spray wire is atomized during thermal spraying.

However, the anti-rust and anti-corrosion method by thermal spraying involves spraying atomized zinc-aluminum alloy onto the surface of iron and copper to form the necessary thermal spray coating, and there is no need to alloy zinc and aluminum from the beginning. do not have. Because zinc and aluminum are alloyed from the beginning, processing the spray wire becomes difficult, and special spray equipment different from that used for zinc spraying is required during thermal spraying.

It is not difficult to work with zinc or aluminum alone, so instead of alloying the thermal sprayed wire from the beginning, it is divided into zinc and aluminum, which are easy to process, and then combined and formed, making it easier to process and make wire rods. will also become more flexible. The present invention has been made based on this idea in order to eliminate the drawbacks of the prior art, and provides an advantageous manufacturing method for producing a composite wire by separating each of the necessary components of a zinc-aluminum thermal sprayed wire. The purpose is to provide the following. That is, the gist of the present invention resides in a method for producing a wire rod for thermal spray coating, which is characterized by supplying molten zinc into a curved aluminum tape, and cooling and solidifying the zinc.

In the zinc-aluminum thermal spray wire according to the above method, aluminum, which is readily available in various shapes, is used as the outer layer or coating, and zinc is placed on the opposite side as the inner layer or core.

In addition, positioning aluminum, which has a higher melting point and thermal conductivity than zinc, on the outside is extremely advantageous in synchronizing the spraying speed of each component during thermal spraying and promoting the formation of an appropriate sprayed alloy layer. . Making each component independent is also extremely advantageous in adjusting the component ratio. Of course, it is preferable that each material used in this case is a single metal, but
There is no problem even if it is an alloy mainly composed of them.

FIG. 1 shows a wire rod according to the present invention, in which 31 is a core made of zinc, 32 is a coating made of aluminum, and there is a gap between the side edges of the coating 32, which is partially filled by the core 31. .

FIG. 2 shows an example of the case where the above-mentioned wire rod is obtained industrially.

A tape 732 serving as the coating 32 is curved in the width direction by the coating forming device T1, passes through a molten zinc bath 731, and contains zinc.

Thereafter, the wire is molded into a predetermined cross-sectional shape through a molding device 72, and if necessary, a die 73 is subsequently used to reduce the area of the wire to make the wire thinner.

Since the thermal sprayed wire obtained in this way is a composite body in which the necessary components are separated, the component ratio can be easily adjusted, the thermal spraying properties are no different from that of alloy wire, and the thermal sprayed layer has the same corrosion resistance as that of alloy wire. It has

Moreover, the molding process can be easily performed in the cold, and the bending process is also extremely easy. Therefore, it is possible to significantly improve workability and productivity, which in turn can significantly contribute to cost reduction. Looking at the thermal spray performance of the zinc-aluminum thermal spray wire according to the present invention, a Zn-26%At composite wire manufactured by the method shown in Figures 2 and 3 was prepared, and a thermal spraying experiment was conducted under the conditions shown in the following table. Ivy.

Melt. Tests were conducted on workability regarding the setting of the spray wire in the spray gun, the feeding status of the spray wire, the spray speed, etc., and the workability of the example was found to be equivalent to that of the conventional zinc wire and alloy wire shown in the comparative example. I found out.

When looking at the X-ray brightness distribution of zinc and aluminum in the sprayed cross section using an X-ray microanalyzer, the distribution of zinc and aluminum is similar in both the composite wire of the example and the alloy wire of the comparative example, indicating that zinc and aluminum coexist well. I found out that

This means that the solvent used in composite wire thermal spraying is sprayed in the form of an alloy of zinc and aluminum, as in the case of thermal spraying with alloy thermal spraying wires, and the sprayed layer is a zinc-aluminum alloy.
This was also confirmed by the fact that zinc and aluminum coexisted when the composite wire was stopped midway through thermal spraying and its tip was analyzed using an X-ray microanalyzer. In addition, in adhesion tests, tensile tests, and corrosion resistance tests,
The example showed similar results to the thermal sprayed wire of the comparative example.

The particularly advantageous feature of the present invention is that the At concentration is 20 to 407
0(17) composite wire can be manufactured without difficulty.

In zinc-aluminum thermal spray wires, it has been recognized from the salt spray test that the Al concentration is related to the corrosion resistance, but in the conventional manufacturing method, the At concentration was at the limit of 15%. According to the above test, the At concentration is preferably 20 to 40%;
In this respect, the present invention has a high concentration of At, which was previously considered impossible.
It is possible to easily produce a concentrated zinc-aluminum thermal spray wire.

As described above, the present invention is significantly improved in ease of manufacture and comparable in characteristics.
The effect on industry is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the wire rod according to the present invention, and FIG. 2 is a sectional view showing a method for manufacturing the wire rod according to the present invention. , <<Is an explanatory diagram showing two. 31: Zinc core, 32: Aluminum coating, 731: Molten zinc, 732: Aluminum tape, 71 and 72: Covering forming device.

Claims (1)

[Claims] 1 Curve the aluminum tape that will be the covering in the width direction,
A method for producing a wire rod for thermal spray coating, comprising the steps of bringing both side edges of the tape close to each other, and continuously supplying molten zinc into a curved aluminum tape, and cooling and solidifying it.