JP2002180230A - Alloy wire rod for thermal spraying - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal spraying material which can maintain corrosion resistance over a long period by adopting a thermal spraying technique in corrosion prevention for a steel bridge or the like and forming a uniform and rigid film on the surface. SOLUTION: The wire rod is an aluminum alloy wire rod for thermal spraying containing 5 to 15 wt.% zinc, or a zinc alloy wire rod for thermal spraying containing 1 to 10 wt.% aluminum. In the zinc alloy wire rod for thermal spraying, granular aluminum is dispersed. The granular aluminum is charged into molten zinc, and dispersed therein in an unmelted state, and then cooled and formed. Further, the diameter of the granular aluminum is 1 to 50 μ.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal spray material for forming a thermal spray coating on a wall or the like by arc spraying.
In particular, the present invention relates to a coating material having excellent corrosion resistance for preventing corrosion of a steel bridge or the like.

[0002]

Conventionally, a coating technique has been widely used as a means for protecting a structure which is easily exposed to a corrosive atmosphere such as a steel bridge. However, these structures must be regularly repainted, and repainting is indispensable in order to maintain corrosion resistance even when the coating technique and the undercoating technique are improved.

[0003] On the other hand, as an alternative to painting, a bridge may be constructed of weather-resistant steel, or hot-dip galvanizing may be applied to the surface of the steel. However, weather-resistant steel is expensive and galvanizing is more expensive than painting. Although the life cycle is longer, it is still necessary to make regular repairs.

[0004] The present invention is to solve the above-mentioned problems of the prior art, and to maintain the corrosion resistance for a long period of time by employing a thermal spraying technique to prevent corrosion of steel bridges and the like and forming a uniform and firm film on the surface. It is an object of the present invention to disclose a thermal spraying material that can perform the following.

[0005]

Means for Solving the Problems In the present invention, two types of wire rods, ie, a zinc alloy and an aluminum alloy, which are intended to be applied in the present invention, are contacted with a zinc alloy and an aluminum alloy, and an electric current is applied to each of them. The molten metal is adhered to a wall surface or the like by a jet while melting. Thus, a film in which zinc and aluminum are laminated irregularly is formed. Since this thermal spraying method sprays two types of thermal spraying materials simultaneously to form a coating, it is called composite thermal spraying, and this term will be used appropriately hereinafter. However, since the melting point of zinc is 419.47 ° C. and the melting point of aluminum is 660.2 ° C., aluminum does not melt sufficiently during arc spraying, sparks are generated, and the workability is adversely affected. Further, the formed film is in an inhomogeneous state with a large porosity. To avoid this,
An alloy wire in which the composition of zinc and aluminum is half each, and in the case of flame spraying, an alloy wire of 85% zinc and 15% aluminum are used. However, currently known thermal spray coatings using the above-mentioned wire are poor in adhesion to the surface of the base material and easily form porous. Further, the flame sprayed coating involves fine oxide particles and tends to reduce the corrosion resistance. For these reasons, application to surface treatment of steel bridges, etc., has not been widely spread at present.

However, the inventors have paid attention to the advantages of the thermal spraying technique, and have specified a material that can form a uniform surface film as a thermal spraying material while using zinc and aluminum as the material of the wire as in the prior art. And In the present invention, as such a material, zinc is added to aluminum in an amount of 5-1.
The material of claim 1 containing 5% by weight and the material of claim 2 containing 1 to 10% by weight of aluminum in zinc are disclosed. In these combinations, the aluminum alloy is in a completely molten state, almost no spark is generated, and workability is improved. Zinc alloys do not substitute pure zinc for thermal spraying work, but because they are alloys in terms of forming a composite thermal spray coating, coatings that are more familiar and have a higher degree of completeness than coating uniformity and porosity are small. It is formed. The reason why the maximum content of aluminum is specified to be 10% by weight in the alloy according to claim 2 is that the corrosion prevention of the steel material utilizes the sacrificial anodic action of the film, and that the sacrificial anodic action is sufficiently effective. It is desirable that the amount of zinc in the coating be large, at least 60% by weight or more,
This is to prevent zinc in the formed film from being less than 60% by weight in all combinations of the above alloys.

As another structure of the zinc alloy, a thermal spraying wire in which aluminum particles are uniformly dispersed is adopted as disclosed in claim 3. Further, as disclosed in claim 4, granular aluminum is charged into molten zinc in a range of 1 to 10 by weight%, dispersed in an insoluble state, and then cooled to form a wire for thermal spraying. In this state, the aluminum particles are mechanically mixed and dispersed in the zinc, and the ductility of the zinc is hardly changed from that of the pure zinc, so that the plastic working into a wire or the like is easy. Thus, the wire disclosed in claim 3 can be easily manufactured by utilizing the difference in melting point between zinc and aluminum. Furthermore, in consideration of the wire rod diameter, the granular aluminum diameter is used in the range of 1 to 50 μm.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail. In the present embodiment, the aluminum alloy wire of claim 1 and the zinc alloy wire of claim 2 or 3 are paired and electrically sprayed with an arc to obtain a composite sprayed coating on the surface of the base material. First, as a precautionary point in construction, it is necessary to adjust the base to be sprayed. This is to ensure the adhesion of the coating to the base material, but this adhesion is because mechanical engagement with the rough surface of the base material is important. The rough surface can be obtained by applying a rough surface forming material or appropriately roughening the base material surface by blasting. As an example of a material capable of obtaining an appropriate surface roughness, a material obtained by mixing ceramic particles with an epoxy resin is used as the rough surface forming material.

Next, a known arc spraying machine is used for the thermal spraying, but it is desirable to perform the thermal spraying at a low temperature so as to reduce the influence of the thermal strain. The distance from the tip of the thermal spray nozzle to the processing surface must be kept constant in order to keep the film thickness constant.
It is preferred to spray at an angle of degrees.

The thermal spray coating obtained in this way is porous with flat particles deposited thereon, but the particles are in close contact with each other due to the mechanical anchoring effect. If the surface temperature of the base material is too low, the internal strain increases due to rapid cooling, and it is desirable that the temperature be equal to or higher than the outdoor temperature plus 3 ° C. in order to avoid condensation on the surface of the base material.

The coating thus obtained is subjected to a sealing treatment when pores are found in the final inspection. For the sealing treatment, a material that impregnates the pores is used.

Further, although not mentioned in the present embodiment, it is possible to freely adopt a method of forming a thermal spray coating and further applying a coating. Needless to say, the diameter and length of the wire are appropriately selected depending on the magnitude of the current used for arc spraying, temperature and humidity conditions, and the like.

[0013]

According to the present invention, three types of wires are used as wires used for arc spraying. However, when a film is formed on a base material by a normal arc spraying method, a dense and uniform film is obtained. I was able to. The sprayed coating thus obtained is porous with zinc-rich and aluminum-rich flat particles deposited, but compared to the case of using pure zinc and pure aluminum wires, the flat particles have different concentrations of zinc aluminum. Since the alloy was an alloy, the compatibility between the particles was good, the whole was homogeneous, the porosity was small, and a film extremely ideal for anticorrosion could be formed.

 ──────────────────────────────────────────────────続 き Continuation of the front page (71) Applicant 500562086 Ryosai Saito 3-14-1 Narusedai, Machida-shi, Tokyo (71) Applicant 500562097 Haruo Hamaki 4-130-8, Rokutakadai, Matsudo-shi, Chiba (71) Application 500562101 ISG Co., Ltd. 5-6-13 Nishinakajima, Yodogawa-ku, Osaka-shi, Osaka (72) Inventor Ariyasu Kurimoto 2-10-11-11110 Higashi-Mikuni, Yodogawa-ku, Osaka-shi (72) Inventor Eiji Tsuji Osaka 1-18-16 Saidera, Suita-shi (72) Inventor Tomoyuki Mizukoshi 3-23-3-201 Kitahanada-cho, Sakai-shi, Osaka F-term (reference) 4K031 AA08 AB02 AB09 BA01 CA01 CA03 CB37 DA03

Claims (5)

[Claims] An alloy wire for thermal spraying aluminum containing 5 to 15% by weight of zinc. 2. An alloy wire for zinc spraying containing 1 to 10% by weight of aluminum. 3. The method as claimed in claim 2, wherein aluminum particles are dispersed.
The described alloy wire for thermal spraying. 4. The alloy wire for thermal spraying according to claim 3, wherein the granular aluminum is put into molten zinc, dispersed in an insoluble state, and then cooled and formed. 5. The alloy wire for thermal spraying according to claim 3, wherein the granular aluminum diameter is 1 to 50 μm.