JPH0913160A - Hot-dip metal coated steel wire excellent in wear resistance - Google Patents

Abstract

PURPOSE: To produce a hot-dip metal coated steel wire exhibiting excellent resistance to wear and corrosion even when the wires are jostled with one another as in the case when the wires are reticulated and used. CONSTITUTION: Two hot-dip plating layers having a different composition are formed on a steel wire. The first layer on the steel wire side contains 40-60wt.% Al, 30-40wt.% Fe and the balance Zn, and the second layer on the surface side contains 2-10wt.% Al and the balance Zn. The coating weight of the first layer is preferably controlled to 10-200g/m<2> to obtain excellent wear resistance, the coating weight of the second layer should be controlled to >=100g/m<2> to attain excellent corrosion resistance, and the total coating weight of the first and second layers has to be controlled to >=250g/m<2> .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-dip galvanized steel wire having excellent wear resistance, and more specifically, conditions under which hot-dip galvanized steel wires rub against each other, such as when a hot-dip galvanized steel wire is processed into a net shape. The present invention relates to a hot-dip galvanized steel wire that exhibits excellent durability even when used below.

[0002]

2. Description of the Related Art Hot-dip Zn plating is a technique that is widely used as a method for improving the corrosion resistance of steel products such as steel plates and steel wires. Further improvement in corrosion resistance is attempted by applying a coating to. On the other hand, in the case of steel wire, it is often used without coating or the like, and it is expected that the Zn plating layer alone will exhibit sufficient corrosion resistance. Therefore, it is preferable that the coating weight of the hot-dip steel wire is large, and specifically, the coating weight of 250 g / m ² or more is required.

Zn containing a small amount of Al in Zn
-Al plating is known to have better corrosion resistance than pure Zn plating. However, in the case of the above-mentioned Zn-Al plating, a sufficient amount of coating adhesion cannot be obtained by performing the hot dip only once, so a two-bath method in which the hot dipping is performed twice is proposed. . For example, Tokuho 5
In JP-A-40024 and JP-A-4-154949, first, pure Zn plating is performed, and then Zn-Al plating is performed at a temperature at which a Zn plating layer is not melted, so that a sufficient amount of plating adhesion can be obtained. A method of manufacturing the plated steel wire has is disclosed.

By the way, as a field of application of the plated steel wire, a plurality of steel wires are often used in a net-like combination, for example, as in a mesh net or a fence. Therefore,
During use, the steel wires are rubbed against each other, so that the hot-dip plated layer is locally worn and easily lost. If the hot-dip galvanized layer is worn, although locally, the corrosion preferentially progresses from the worn portion and the life of the steel wire product is significantly shortened. Therefore, in order to improve the durability of the steel wire product, it is necessary to improve not only the corrosion resistance of the plating layer but also the wear resistance.

The plated steel wire obtained by the above-mentioned manufacturing method is
Although excellent in terms of corrosion resistance, any plated steel wire has a soft plating layer and poor wear resistance, so corrosion that preferentially occurs in the worn part cannot be avoided, and the above steel wire was commercialized. There was a problem that the durability afterwards was not sufficient.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of these circumstances, and it is an object of the present invention to provide a hot-dip galvanized steel wire having excellent corrosion resistance and wear resistance.

[0007]

Means for Solving the Problems The hot-dip galvanized steel wire according to the present invention which achieves the above object is a hot-dip galvanized steel wire in which two hot-dip galvanized layers having different compositions are formed on the steel wire. The first layer on the steel wire side is Al: 40 to 60% by weight and F
e: 30 to 40% by weight, the balance substantially consisting of Zn, and the second layer on the surface side contains Al: 2 to 10% by weight and the balance substantially consisting of Zn. It is what

In order to obtain excellent wear resistance, the above first
Coating weight of the layer is preferably 10 to 200 g / m ^2, and in order to obtain excellent corrosion resistance, the coating weight of the second layer is preferably set to be 100 g / m ² or more, further wherein It is recommended that the total coating weight of the first layer and the second layer be 250 g / m ² or more.

In the hot dip plated layer, La, C
e, Na, Mg, Ni, Cu, Cr, Co, Mn, 1 or 2 or more selected from the group consisting of 0.0 in total.
The addition of 05 to 0.1% by weight is also effective for improving the corrosion resistance.

[0010]

In the hot dip plated steel wire of the present invention, the first layer is A
1 to 40 to 60% by weight and Fe to 30 to 40% by weight, and the balance consists essentially of Zn. Specifically, a metal in which a small amount of Zn is dissolved in Fe ₂ Al ₅ It is an intermetallic compound layer. This first layer has excellent corrosion resistance and
Since it is hard and has excellent wear resistance, it will not be scraped or peeled off even if the steel wires rub against each other.

Since the first layer is a hard intermetallic compound, cracks may occur when it is processed. However, in the hot-dip galvanized steel wire of the present invention, since the soft second layer is formed on the hard first layer,
Even if a crack occurs in the first layer, the second layer having excellent ductility can stretch following the deformation of the base material. Therefore, the cracked portion of the first layer can also be covered with the second layer, the surface can be completely covered, and the base iron can be prevented from being exposed. Moreover, since the second layer has an excellent sacrificial anticorrosion ability against steel, it is possible to suppress the corrosion of the base material even at a flawed portion reaching the base material or a cut end surface.

As described above, according to the present invention, the first layer which is a hard intermetallic compound layer is formed on the steel wire side, and the first layer which is soft and has an excellent sacrificial corrosion resistance against steel is formed. By forming two layers, wear resistance and corrosion resistance can be satisfied at the same time, and the durability of the steel wire product has been remarkably improved. The requirements specified in the present invention will be described below.

In the present invention, the composition of the first layer is from 40 to
It is necessary that 60 wt% Al, 30-40 wt% Fe, and the balance be essentially Zn. By satisfying this composition range, the first layer is composed of Fe ₂ Al ₅ and a small amount of Zn.
Becomes a hard intermetallic compound single phase solid solution, and exhibits excellent wear resistance, but when the concentration of at least one of Al and Fe deviates from this composition range,
Since the soft second phase is mixed, the wear resistance is significantly reduced. Therefore, in order to obtain excellent wear resistance, the first layer needs to satisfy the above composition range.

The composition of the second layer is 2 to 10% by weight of Al.
And the balance is essentially Zn. Al
By setting the concentration within this range, the corrosion resistance of the Zn-Al layer can be improved to 2 to 3 times that of the pure Zn layer, and the sacrificial anticorrosive ability for steel becomes equivalent to that of the pure Zn layer. If the Al concentration is less than 2% by weight, the effect of improving the corrosion resistance is not sufficient. On the other hand, if the Al concentration is too high, the corrosion resistance may decrease depending on the operating environment.
Was set as the upper limit.

In the present invention, the adhesion amount of the first layer is 10-2.
It is preferably set to 00 g / m ² . If the amount of the first layer deposited is less than 10 g / m ² , the effect of improving wear resistance is not sufficient. On the other hand, when the adhesion amount of the first layer exceeds 200 g / m ² , the effect of improving the wear resistance is saturated, and the crack width of the first layer due to processing increases, and even if the second layer is formed, the base metal It is not possible to extend following the above deformation, and the corrosion resistance of the processed portion may deteriorate. In addition, the adhesion amount of the first layer is 50
It is more preferable that it is 150 g / m ² .

It is recommended that the adhesion amount of the second layer is 100 g / m ² or more. Adhesion amount of the second layer is 100 g / m
^If it is less than ² , the cracks generated in the first layer may not be completely covered by the processing, which may deteriorate the corrosion resistance of the processed portion. Therefore, it is preferable that the adhesion amount of the second layer is 100 g / m ² or more.
More preferably, it is at least g / m ² .

The total amount of the hot-dip galvanized layer, which is the total of the first layer and the second layer, is preferably 250 g / m ² or more. If this total amount of adhesion is less than 250 g / m ² , the corrosion resistance required when the hot-dip galvanized steel wire is used without coating and bare cannot be satisfied. Therefore, the total amount of adhesion is preferably 250 g / m ² or more, and more preferably 300 g / m ² or more.

Further, in the present invention, La, Ce, Na, Mg, Ni, Cu, Cr,
Corrosion resistance can be further improved by adding 0.005 to 0.1% by weight in total of one or more metal elements selected from the group consisting of Co and Mn. Among the above metal elements, La, Ce and Na improve the corrosion resistance by improving the uniform adhesion of the hot-dip plated layer, and Mg, Ni, Cu, Cr, Co and Mn are
The corrosion resistance of the hot-dip plated layer itself can be improved.
However, if the total content is less than 0.005% by weight, the effect of improving corrosion resistance is not sufficiently exerted, and if it is too large, the effect of improving corrosion resistance is saturated and the surface appearance is deteriorated.
It is desirable that the upper limit be weight%.

In the present invention, the type of steel wire as the material to be plated is not particularly limited, and any type of steel wire such as hard steel wire, mild steel wire (iron wire), alloy steel wire and the like which are widely used. By forming the first layer and the second layer of the present invention using the above as a base material, it is possible to obtain excellent wear resistance and corrosion resistance.

Although the present invention is not limited by the manufacturing method, it can be manufactured, for example, by the two-bath method. In the case of using the two-bath method, first, pure Zn plating is performed, and then the temperature (450 to 5) at which the Zn plating layer melts.
It may be immersed in a Zn-Al plating bath heated to 50 ° C. The process of forming the first layer and the second layer of the present invention by this two-bath method can be explained as follows. That is, when the steel wire surface is immersed in the pure Zn plating bath of the first bath, F
An e-Zn alloy layer is formed, and the upper layer becomes a Zn plating layer. Then, when immersed in a Zn-Al plating bath of the second bath, the Zn plating layer was eluted, the Fe-Zn alloy layer was combined with Al, and an Fe-Al intermetallic compound containing Zn as a solid solution was formed. It is considered that the first layer composed of the layers is formed and the second layer composed of Zn-Al plating can be formed on the first layer.

It is known that even the conventional hot-dip galvanized steel wire manufactured by using the two-bath method has an Al content of the first layer of up to about 30% by weight. However, the hot-dip galvanized steel wire did not have sufficient wear resistance.

Examples will be described below, but the present invention is not limited to the following examples, and it is within the technical scope of the present invention to make appropriate modifications within the spirit of the preceding and following items.

[0023]

【Example】

[Example 1] As a material to be plated, a mild steel wire (iron wire: JIS G 35
05 SWRM6 equivalent) was used to form the hot-dip coating layer shown in Table 1, and the wear resistance, corrosion resistance, and workability were examined by the following methods. The compositions and amounts of the first layer and the second layer were analyzed by atomic absorption spectrophotometry after dissolving each hot-dip layer with a predetermined solution.

Abrasion resistance test Two test steel wires are piled up in a cross shape, and a 1 kg weight is placed on the upper test steel wire, and rubbed against the lower test steel wire once. 1000 at a distance of 100 mm
I made a round trip. The wear resistance was evaluated according to the following criteria from the peeling state of the hot-dip coating layer of the lower test steel wire. ○: Hot-dip galvanized layer No peeling △: Hot-dip galvanized layer partially peeled ×: Hot-dipped galvanized layer Front peeling

Corrosion resistance test A salt spray test according to JIS Z 2371 was carried out for 1000 hours, then the corrosion weight loss was measured, and the corrosion resistance was evaluated according to the following criteria. ◎: Corrosion weight loss less than 100g / m ² ○: Corrosion weight loss 100g / m ² or more but less than 200g / m ² △: Corrosion weight loss 200g / m ² or more but less than 400g / m ² ×: Corrosion weight loss 400g / m ² or more

Workability test 3d by winding method according to JIS Z 2248
The processed part of the bent test material was observed under a microscope, and the workability was evaluated according to the following criteria from the exposed state of the base iron. ○: No exposed bare metal △: Small exposed bare iron ×: Large exposed bare iron

[0027]

[Table 1]

No. 1 to 9 are examples in which the first layer and the second layer satisfying the requirements of the present invention are formed, and wear resistance,
It has excellent corrosion resistance and workability. On the contrary,
No. Nos. 10 to 23 are comparative examples that do not satisfy at least one requirement of the present invention, and are inferior in at least one of wear resistance, corrosion resistance, and workability.

[Example 2] La, Ce, Na, Mg, N
1 selected from the group consisting of i, Cu, Cr, Co and Mn
Abrasion resistance, corrosion resistance, and workability were examined in the same manner as in Example 1 except that a hot-dipped steel wire containing one or more kinds in the hot-dipped layer was used. The results are shown in Table 2.

[0030]

[Table 2]

La, Ce, Na, Mg, Ni, Cu, C
N containing 0.005 to 0.1% by weight in total of one or more selected from the group consisting of r, Co, and Mn.
o. It can be seen that 24 to 32 are particularly excellent in corrosion resistance. No. 33 and 34 are comparative examples when the content of the trace element is too large, and although the wear resistance, the corrosion resistance and the workability are excellent, the unevenness of the plating layer surface becomes severe and the appearance deteriorates.

[0032]

EFFECTS OF THE INVENTION Since the present invention is constituted as described above, it is possible to provide a hot-dip galvanized steel wire having excellent corrosion resistance as well as wear resistance, and durability when the hot-dip galvanized steel wire is used in a reticulated product. It has become possible to significantly improve the sex.

Claims (5)

[Claims] 1. A hot-dip galvanized steel wire in which two hot-dip galvanized layers having different compositions are formed on a steel wire, and the first layer on the steel wire side is Al: 40-60 wt% and Fe:
It is characterized in that it contains 30 to 40% by weight and the balance substantially consists of Zn, and the second layer on the surface side contains Al: 2 to 10% by weight and the balance substantially consists of Zn. Hot-dip galvanized steel wire with excellent wear resistance. 2. The coating amount of the first layer is 10 to 2
The hot dip galvanized steel wire according to claim 1, which has a weight of 00 g / m ² . 3. The coating weight of the second layer is 100 g
/ M ² or more, the hot-dip galvanized steel wire according to claim 1 or 2. 4. The hot-dip galvanized steel wire according to any one of claims 1 to 3, wherein the total coating weight of the first layer and the second layer is 250 g / m ² or more. 5. La, Ce, Na, Mg, Ni, Cu, Cr, Co, M in the hot-dip plated layer.
The hot dip plated steel wire according to any one of claims 1 to 4, containing 0.005 to 0.1% by weight in total of one or more selected from the group consisting of n.