JP3210396B2 - Manufacturing method of glass reinforcing steel wire with excellent high temperature properties and corrosion resistance - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial application] Glass used in the construction and automotive industries has a steel wire encapsulated in the glass in order to strengthen the glass and prevent scattering at the time of breakage in consideration of safety. The present invention relates to a method for producing the glass reinforcing steel wire, and more specifically, to provide a glass reinforcing steel wire excellent in high-temperature characteristics and corrosion resistance.

[0002]

2. Description of the Related Art Many studies have been made on air bubbles and cracks near the steel wire interface after glass encapsulation, which significantly reduce the commercial value. For example, there is a method of reducing the number of crack initiation points by reducing the surface flaws of a steel wire, and Japanese Patent Publication No. 42-169 discloses a method of suppressing the generation of bubbles and cracking by making the pearlite structure on the surface of the steel wire spheroidized cementite. Japanese Patent Publication No. 47-1474 proposes a method in which steam treatment and phosphoric acid treatment are combined. In addition, it has been found that the effect of this method varies significantly depending on the composition of the steel wire. Furthermore, Japanese Patent Application Laid-Open No. 52-11117 makes a basic study on the generation of air bubbles, but this method still has a problem that the frequency of occurrence of cracks varies. In any case, the problem of cracking cannot be completely solved by such a conventional technique, and a failure that is demoted in a check in the final inspection process occurs. This is especially true for polished glass (clear glass).

As described above, the prior art mainly occupies a technique relating to foaming or crack prevention from the viewpoint of how to align and enclose a steel wire in glass. However, conventional braided glass does not cause much problems at room temperature, but when a fire occurs, the glass tends to fall off at the current high-temperature strength of steel wire, so that secondary disasters and fire spread easily occur. Problems remain, and demands for improvement in strength at high temperatures have increased.

[0004]

SUMMARY OF THE INVENTION Accordingly, the inventors of the present invention intend to improve the high-temperature strength of the steel wire for glass encapsulation, reduce the falling-off rate of glass in a fire, and prevent a secondary disaster in a fire. We have begun research that originally focused on the purpose. Since the steel wire for glass reinforcement basically has to be oriented to low carbon, the strengthening of the steel wire at a high temperature had to mainly aim at solid solution strengthening in ferrite. For this reason, various studies were carried out by adding Mo alone, but it was found that Mo alone increases the strength at high temperatures compared to the case without Mo, but cannot maintain its effect. Therefore, the present inventors sought a composite effect with other elements in order to extend the duration of strengthening at high temperatures, and as a result, by adding Nb, the strength was significantly improved and the time during which the effect was maintained increased. I got the knowledge. The reason is considered to be due to the combined action of precipitation strengthening of NbC and solid solution strengthening of Mo.

[0005]

That is, the method of the present invention comprises:
By weight%, C: 0.020% or less, Si: 0.02% or less
Below, Mn: 0.2-0.4%, Al: 0.003% or less, N: Al / N is 1.3 or less, Mo: 0.1-0.4.
%, Nb: 0.005 to 0.03%, Cu: 0.05 to
0.2%, Ni: 1/3 of the amount of Cu added, steel component consisting of the balance Fe and unavoidable impurities continuously cast into steel slabs, wire rod rolling, and then to a predetermined size Glass reinforcement with excellent high-temperature properties and corrosion resistance, characterized by subjecting a drawn wire to a steel wire annealed to a final strength of 45 to 51 kgf / mm ² and electroplating with a thickness of 2 to 10 μm. It is a method of manufacturing steel wire for use.

[0006]

C is an element that controls the strength of a steel wire, but in the case of a steel wire for glass reinforcement, excessive addition tends to induce bubbles during glass sealing, so the upper limit must be suppressed to 0.020%. There is. Further, if the addition is more than this, the strength at room temperature increases, and when knitting a steel wire, the springback after forming becomes large and it becomes difficult to handle the wire mesh.

Mn is a deoxidizing element and has an effect of suppressing hot brittleness. The upper limit is set to 0.4% because the addition of more than that unnecessarily increases the room temperature strength of the steel wire and impairs the workability of the knitting net process. The reason for setting the lower limit to 0.2% is that if it is less than 0.2%, the butt weldability performed in the wire drawing process will be poor. Although Si is also a deoxidizing element,
The upper limit is set to 0.02%.
This is because there is a risk of increasing the strength of the unnecessarily.

[0008] Al is often used as a deoxidizing element, but at the same time, forms aluminum nitride, so that it has a large effect on the recrystallization behavior of steel wire. Therefore, the present invention has a very important meaning. If the content of Al exceeds 0.003%, a large amount of AlN is generated, the growth of recrystallized grains at the time of enclosing the glass becomes uneven, and a mixed grain structure of coarse grains and fine grains is likely to occur, and it is extremely difficult to control the constant tension. For this reason,
The upper limit is set to 0.003% because the position control of sealing the glass becomes unstable, causing problems such as breaking of the glass during the cooling stage.

N is an element that reacts with Al to form AlN. As described above, the reason why the Al / N ratio is adjusted to 1.3 or less is that if more N is contained, the grain growth of recrystallization is inhibited and smooth grain growth cannot be expected. For this reason, it is difficult to seal the steel wire with a constant tension as in the case of Al.

Mo is an element used in the present invention to improve high-temperature characteristics and plays an important role in the present invention like Nb. In order to improve the high temperature properties by solid solution strengthening of Mo, it is necessary to add at least 0.1%. The reason why the upper limit is set to 0.4% is that Mo is expensive. This is because of saturation.

Nb is a nitride and carbide forming element like Ti. The role of Nb in the present invention is used to fix C and N to reduce aging at room temperature, reduce variations in steel wire strength, and maintain high-temperature strength by the precipitation strengthening action of NbC. The reason for setting the lower limit to 0.005% is that the effect described above does not appear below this lower limit. The upper limit is set to 0.03% because the amount of fine carbides increases, so that the frequency of exposure to the steel wire surface during glass encapsulation increases, and a foaming phenomenon appears like C. Cu is an element that forms a solid solution in steel to increase strength and corrosion resistance. In the present invention, Cu is used for improving corrosion resistance. The surface of the steel wire has excellent corrosion resistance by plating the glass reinforcing wire before being enclosed. However, when the glass is cut into a fixed size after being sealed in the glass, a cut surface is inevitably generated. It is added for the purpose of improving the corrosion resistance of the cross section of the cut steel wire. The lower limit is set to 0.05% because no improvement in corrosion resistance can be expected below this value. On the other hand, to increase the corrosion resistance, it is effective to increase the amount of Cu added. However, the extreme addition unnecessarily increases the strength of the mechanical properties at room temperature, so the upper limit was made 0.2%.

[0012] In the case of Cu-containing steel, Ni is used to prevent surface cracks of the steel slab that occur during hot working. In order to obtain this effect, it is necessary to add 1/3 of the Cu amount corresponding to the Cu amount.

When the lower limit of the strength of the steel wire is set to 45 kgf / mm ² , the required strength cannot be obtained if the lower limit is less than 45 kgf / mm ² . Further, the upper limit is set to 51 kgf / mm ² because if the strength is too high when the steel wire is braided and sealed in a wire mesh, it becomes difficult to maintain a flat surface even when tension is applied to the wire mesh, This is because it is difficult to control the position in the cross-section to be enclosed in the space.

Next, the thickness of the electroplating will be described. The reason why the lower limit is set to 2 μm is that if it is less than 2 μm, the corrosion resistance is extremely poor. In addition, the upper limit is set to 10 μm because the economy is considered from the viewpoint of the manufacturing cost and the effect is saturated. Here, the contents of the plating are not particularly defined, but the operation of the plating will be described. The aim of plating steel wire is as follows. We expect the effect of improving the wettability at the interface between glass and steel wire. Alternatively, any material can be used as long as it can exert an effect such as relaxing the stress acting on the interface between the glass and the steel wire. For example, in the former case, Cr plating is used. In the latter case, tin plating is appropriate. Care must be taken because some types of plating may impair the glass sealing property. For example, usually, the glass temperature at the time of sealing in glass is 1000 to 10
Since it is sealed at about 50 ° C., in the case of Zn plating, since the plated portion is vaporized immediately after being sealed in the glass and a problem such as foaming of the glass occurs, the wettability and the vaporization temperature of the plated portion are selected when selecting the plating type. Is more than 1050 ° C.

[0015]

Embodiments will be described below. All the steels listed in Table 1 were melted in a 250 ton converter, and were continuously cast into slabs of 500 × 200 mm and then rolled into 5.5 mmφ wires. No. 1 to 6 indicate chemical components of the method of the present invention. No. 7, 12, and 13 are conventional steels.
No. 8, 9, 10, and 11 are steel components of the comparative method. Table 2
All the tensile tests for wire and steel wire shown in JIS Z
2241 was performed. The high temperature strength is 600 ° C
After holding for 1 hour, a tensile test was performed. Table 3 shows the water discharge test conditions.

In the method of the present invention, 1 to 6 are all Mo, N
b, Cu and Ni elements are added. For this reason,
As shown in Table 2, no crack was generated at the end of the steel wire after glass sealing due to rust. Also, regarding high temperature characteristics, 600 ° C
Steel wire strength one hour after × more than 20 kgf / mm ^2, a conventional method N
o. The values are higher than 7, 12, and 13. Comparative steels 8, 9, 10, and 11 were Mo, Nb, Cu,
This is a component system excluding Ni from the steel of the present invention. For this reason, No. 8 and No. No. 9 has a low high temperature strength.
No. Since No. 10 does not contain Cu, cracks due to corrosion of the end of the steel wire are recognized.

Further, when a water discharge test is performed under the conditions shown in Table 3, the conventional method falls off in 12 seconds or less, whereas the method of the present invention shows that there is no dropout in 30 seconds. . In Comparative method 10, although Mo and Nb were added, the particles did not fall off in 30 seconds, but as shown in Table 2, cracks occurred due to rust after the glass was sealed. The results described above are based on the effect of Cu and Ni on the corrosion resistance and on the effect of Mo and Nb on the increase in high-temperature strength. In any case, it can be seen that satisfying both characteristics cannot be achieved unless the requirements of the present invention method are satisfied.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

[0021]

According to the present invention, it is possible to produce a glass-filled glass having excellent high-temperature properties and corrosion resistance. Therefore, rusting after glass encapsulation and an accident such as a fire after installing the glass-filled glass in a building or the like may occur. It is an object of the present invention to provide a steel wire for glass encapsulation that can contribute industrially and socially, for example, when it occurs, it is highly effective in preventing a secondary disaster or fire spread due to glass collapse.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C21D 8/00-8/10 C21D 9/52 103 C25D 7/06 C22C 38/00-38/60

Claims (1)

(57) [Claims] 1. In weight%, C: 0.020% or less, Mn: 0.2 to 0.4%, Si: 0.02% or less, Al: 0.003% or less, N: Al / N 1.3 or less, Mo: 0.1 to 0.4%, Nb: 0.005 to 0.03%, Cu: 0.05 to 0.2%, Ni: 1/3 addition of Cu amount, balance Fe After continuously casting a steel component consisting of unavoidable impurities into a billet, rolling the wire rod, and then performing wire drawing to a predetermined size, and having a final strength of 45 to 51 kgf / mm ^2.
A method for producing a glass reinforcing steel wire having excellent high-temperature characteristics and corrosion resistance, wherein a steel wire annealed so as to have a thickness of 2 to 10 μm is electroplated.