JPH06299361A - Repairing method of extra fine steel wire - Google Patents

Abstract

PURPOSE:To provide a repairing method of an extra fine steel wire being superior in an improving effect against corrosion resistance at a temp. not changing a metal structure of the extra fine steel wire and also even at the thin plating layer. CONSTITUTION:In the repairing method of the extra fine steel wire, an electroless plating for an electrochemical noble metal nobler than iron is applied on the extra fine steel wire with <=1mm wire diameter which was obtained by drawing a preliminarily plated steel wire. A seed of plating before the drawing is a nickel plating and also a seed of plating after the drawing is preferably a nickel plating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing ultrafine steel wire.

[0002]

2. Description of the Related Art Generally, when drawing a steel wire, a treatment for imparting lubricity to the steel wire is performed. As one of the lubricating treatment methods, there is a method of plating a steel wire before drawing. This pre-drawing plating has an advantage that it can simultaneously impart corrosion resistance to the drawn steel wire. Nickel plating is preferably used for this pre-drawing plating species because of its malleability.

However, the plated steel wire 1
When cold drawing wire drawing is performed on (see FIG. 1A), the plating layer 2 is drawn nonuniformly as shown in FIG. 1B, and drawing further progresses to reduce the thickness of the surface plating layer. Then, as shown in FIG. 1C, a portion (a) where the iron base is partially exposed is generated, and there is a problem that the corrosion resistance of the steel wire is significantly deteriorated. In addition to the above causes, the corrosion resistance may be deteriorated due to the exposure of the iron substrate due to the pinholes in the plating layer and the scratches generated during wire drawing. For this reason, it is necessary to coat the part that causes the deterioration to improve the corrosion resistance, but for ultrafine steel wire having a wire diameter of 1 mm or less after drawing, it is necessary to coat it as thin as possible.

In general, when a steel wire is coated for the purpose of imparting corrosion resistance, galvanization by an electroplating method or a hot dipping method is used. However, not only in the case of zinc, but in the hot-dip plating method, the material to be plated is treated at a high temperature, so that the metal structure may change especially in an ultra-fine steel wire, and it is difficult to control the plating thickness finely. For some reason, it is unsuitable as a coating method for ultrafine steel wire. On the other hand, the electroplating method enables thin plating at a temperature that does not change the structure of the steel wire,
With this method, the entire steel wire is covered, so it is not possible to cover only the exposed part of the iron base material, and a large number of pinholes result in a poor effect of improving the corrosion resistance with a thin coating. It is also unsuitable as a coating method for extra-fine steel wires because it is disadvantageous in terms of cost and the like.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and has an effect of improving corrosion resistance even at a thin plating layer at a temperature that does not change the metal structure of an ultrafine steel wire. It is intended to provide an excellent method for repairing an ultrafine steel wire.

[0006]

[Means for Solving the Problems] A method for repairing an ultrafine steel wire according to the present invention that achieves the above object is to obtain an ultrafine steel wire having a diameter of 1 mm or less obtained by drawing a pre-plated steel wire. The point is that electroless plating of a noble metal is performed. Further, it is a preferred embodiment of the repair method of the present invention that the plating species before wire drawing is nickel plating and the electroless plating species after wire drawing is also nickel plating.

[0007]

The present inventors have studied a method of repairing a steel wire suitable for improving the corrosion resistance of an ultrafine steel wire that has been plated before drawing, and as a result, have performed electroless plating treatment on the ultrafine steel wire after drawing. As a result, the plating can be preferentially deposited on the exposed portion of the iron base material that is the cause of the deterioration of the corrosion resistance. Therefore, it has been found that the exposed portion of the iron base material can be repaired to prevent the deterioration of the corrosion resistance. The electroless plating is suitable for repairing ultrafine steel wire because it has advantages such as low processing temperature, few pinholes, and thin plating. Since the present invention focuses on a method for repairing an ultra-fine steel wire after wire drawing, the plating species before wire drawing is not particularly limited, but nickel is preferable because its extensibility is good. Also,
The plating method at this time is not limited, and electric, melting, and other known plating methods can be adopted. The plating thickness is not particularly limited as long as it is within the range suitable for the wire drawing process.

The electroless plating species to be used after wire drawing is not particularly limited as long as it is a metal nobler than iron, but nickel, copper, tin, gold, cobalt and the like can be mentioned. An electroless plating species (for example, nickel) in which iron has a catalytic action can be more preferably used because it is possible to preferentially coat the exposed portion of the iron substrate which causes deterioration of corrosion resistance. That is, since the electroless nickel plating uses iron as one of the catalytic metals, iron is first eluted from the exposed portion of the iron substrate by the catalytic action thereof, and a substitution reaction with nickel ions occurs to deposit nickel. As a result, nickel precipitation in the periphery of the exposed portion of the iron base material occurs preferentially, and the exposed portion of the iron base material is surely covered, so that the corrosion resistance of the ultrafine steel wire is significantly improved.

Further, it is more effective to perform an electroless nickel plating treatment on an ultrafine steel wire plated with nickel before drawing. This is because the nickel plating remaining on the surface of the ultra-fine steel wire before the wire drawing and the electroless plating for repair are nickel-based, so the adhesion is excellent and the wear resistance is also excellent. There is also. The electroless nickel plating method includes various methods such as the case of using a phosphorus-based reducing agent and the case of using a borohydride-based reducing agent, but any method can be used.

The thickness of the electroless plating layer applied to the ultrafine steel wire is preferably 0.05 to 10 μm. If the plating layer is 0.05 μm or less, the plating layer is too thin and the repair effect and the corrosion resistance improving effect are insufficient, and even if the plating layer is 10 μm or more, significant improvement in corrosion resistance cannot be expected and it is not economical.

[0011]

The present invention will be described in more detail with reference to the following examples, but the following examples do not limit the present invention.
All modifications and implementations that do not depart from the spirit of the description below are included in the technical scope of the present invention.

EXAMPLES AND COMPARATIVE EXAMPLES Steel wire which had been electro-nickel plated before wire drawing was subjected to cold pressure drawing to obtain an ultrafine steel wire having a diameter of 50 μm. This steel wire was cut into 20 cm, and electroless plating was performed by a batch method of immersing in a plating bath having a bath composition shown in Table 1, and the plating thickness was changed by changing the immersion time. An ultrafine steel wire was obtained. JIS-Z-237 is applied to these steel wires.
A salt spray test was carried out according to 1, and evaluation was made based on the red rust generation time. The results of the corrosion resistance test are also shown in Table 1.
Further, as comparative examples, electro-nickel plated samples (No. 7 to No. 10) having the thicknesses shown in Table 1 were prepared, and a corrosion resistance test was conducted in the same manner as in Examples, and the results are shown in Table 1.

[0013]

[Table 1]

As is clear from Table 1, the electroless plated examples (Nos. 1 to 6) have a thinner plating thickness than the comparative examples (Nos. 7 to 10) which are electroless nickel plated. A significant improvement in corrosion resistance is obtained.

[0015]

According to the present invention, it is possible to effectively repair the exposed portion of the iron base material, which has been a cause of deterioration of the corrosion resistance of the ultrafine steel wire, by electroless plating. This makes it possible to improve the corrosion resistance of the ultrafine steel wire.

[Brief description of drawings]

FIG. 1A is a schematic sectional view of a steel wire plated before wire drawing, B is a schematic sectional view of an ultrafine steel wire plated before wire drawing during wire drawing, and C is before wire drawing. FIG. 3 is a schematic cross-sectional view of an ultrafine steel wire plated on a wire after drawing.

[Explanation of symbols]

 1 Iron 2 Plating layer a Exposed part of iron substrate caused by wire drawing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masaki Tanigawa Masaki Tanigawa 2222 Ikeda, Ikeda, Igami, Onoe Town, Kakogawa City, Hyogo Prefecture 1 Kakogawa Research Area, Kobe Steel Co., Ltd. (72) Tomio Kajita, Onoe Town, Kakogawa City, Hyogo Prefecture Ikeda character Ikeda development 2222 Address 1 Kakogawa Research Area, Kobe Steel, Ltd.

Claims (2)

[Claims] 1. Repair of an ultra-fine steel wire, characterized by subjecting an ultra-fine steel wire having a diameter of 1 mm or less obtained by drawing a pre-plated steel wire to electroless plating of a metal nobler than iron. Method. 2. The method for repairing an ultrafine steel wire according to claim 1, wherein the plating species before wire drawing is nickel plating, and the electroless plating species after wire drawing is also nickel plating.