JP2955385B2 - Manufacturing method of steel wire for glass reinforcement with excellent high temperature properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial application] Glass used in the construction and automotive industries has a steel wire enclosed in the glass in order to strengthen the glass and prevent scattering when broken in consideration of safety.
The present invention relates to a method for manufacturing a glass reinforcing steel wire, and more specifically, to provide a glass reinforcing steel wire having excellent high-temperature characteristics.

[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 crack origin by reducing the surface flaw of the steel wire, and Japanese Patent Publication No. Sho 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 into spheroidized cementite. Japanese Patent Publication No. 47-1474 proposes a method combining steam treatment and phosphoric acid treatment. In addition, it has been found that the effect of this method varies significantly depending on the composition of the steel wire. 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 meshed glass is not a problem at room temperature, but when a fire occurs, the glass tends to fall off at the current high-temperature strength of steel wire, which causes secondary disasters and fire spread. 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, it was necessary to strengthen the steel wire at a high temperature mainly for solid solution strengthening of ferrite.

[0005] For this reason, various studies were conducted 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.

[0006]

According to the present invention, C: 0.02
0% or less, Mn: 0.2 to 0.4%, Al: 0.003
% Or less, Al% / N%: 1.3 or less, Mo: 0.1% or more
0.5%, Nb: 0.005% to 0.06%, Cr:
0.1 to 0.5%, Cu: 0.05 to 0.2%, Ni is added to 1/3 to 1/2 of the amount of Cu, and the remainder is a steel rod of a steel component consisting of unavoidable impurities. After that, a method for producing a glass reinforcing steel wire having excellent high-temperature characteristics, comprising drawing a wire to a predetermined size and plating the surface of the steel wire in a final step.

[0007]

C is an element that controls the strength of the steel wire. However, in the case of a steel wire for reinforcing glass, the upper limit must be suppressed to 0.020% because excessive addition easily induces the generation of bubbles at the time of sealing the glass. There is. Further, if it is added more than this, the strength at normal temperature increases, and when knitting the 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 Al is often used as a deoxidizing element, it forms aluminum nitride at the same time, and therefore has a large effect on the recrystallization behavior of steel wires. 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 nonuniform, and a mixed grain structure of coarse grains and fine grains is easily formed, 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. The effect is as described for the limitation of Al. Al
The reason why / N is adjusted to 1.3 or less is that if N is contained more than this, the grain growth of recrystallization is hindered, so that smooth grain growth cannot be expected. This is because it becomes difficult to enclose with a constant tension.

Mo is an element used in the present invention for improving high-temperature characteristics and has an important role in the present invention like Nb. In order to improve the high temperature characteristics by solid solution strengthening of Mo, it is necessary to add at least 0.1%. The upper limit is set to 0.5% because Mo is expensive and the effect is saturated when Mo is added further.

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 why the lower limit is set to 0.005% is that below this value, the above-mentioned effects are not exhibited. The upper limit is set to 0.06% 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 as in C.

Since Cr forms carbides, it is used to fix C in steel and is used to prevent bubbles from being generated.
High temperature strength can also be improved by adding r. Therefore, 0.1% is added as a minimum amount to exhibit the effect. The upper limit is set to 0.5% because the effect is saturated when added in excess.

Cu is an element that forms a solid solution with steel to increase strength and corrosion resistance. In the present invention, Cu
Is used to improve 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. Set the lower limit to 0.
The reason for setting it to 05% is that if it is less than this, improvement in corrosion resistance cannot be expected. On the other hand, it is effective to increase the amount of Cu added to increase the corrosion resistance, but the extreme addition unnecessarily increases the strength of the mechanical properties at room temperature.
2%.

In the case of Cu-containing steel, Ni is used to prevent surface cracks of the steel slab that occur during hot working. To obtain this effect, the minimum addition amount is required to be 1/3 of the Cu amount, and the upper limit is set to 1/2 of the Cu addition amount at which this effect is saturated.

[0016] Plating is performed in the final stage of the manufacturing process of the reinforcing steel wire. Although the plating method is not particularly limited, electroplating with high smoothness on the surface of the steel wire is preferable. More specifically, Cr plating is preferable in consideration of wettability with glass.
In addition, electric Ni plating is also effective. That is,
As long as the steel wire surface does not come into direct contact with the glass and has good wettability with the glass, it is possible to prevent air bubbles generated on the steel wire surface and cracks due to heat shrinkage during cooling. All platings having these properties are the subject of the present invention. Next, examples will be described.

[0017]

EXAMPLES All the steels shown in Table 1 were melted in a 250 ton converter, and then continuously cast to 500 × 300 m.
m, and then a 122 mm square steel slab. After that, wire rolling was performed to obtain a 5.5 mm wire. Further, wire drawing was performed to make the final steel wire diameter 0.57 mm.

No. 1 to No. 6 shown in Table 1 indicate steels used in the method of the present invention. On the other hand, No. 7 to No. 9 are shown as comparative methods. No. 7 does not include Cr, Cu and Ni in the method of the present invention. No. 8 has no Cr, Mo and Nb added. No. 9 is a level in which Mo, Nb, Cu, and Ni are not added and final plating is not performed. The plating treatment shown in Table 1 was performed by electrochromic plating.

Next, an evaluation method will be described. Table 2 shows the results of holding at room temperature and at 600 ° C. for 1 hour. The appearance of the glass-filled glass was observed by visual observation to determine the occurrence of cracks. The occurrence of cracks at the end of the steel wire is JISZ23
A salt spray test specified in No. 71 was performed, and the occurrence of cracks after the test was visually observed. Table 3 shows the results of the water discharge test assuming an actual fire. Using the test conditions described in Table 3, the time until the glass came off was measured.

[0020]

[Table 1]

[0021]

[Table 2]

From the results shown in Table 2, it can be seen that the high temperature strength, which is the object of the present invention, is clearly improved in the method of the present invention as compared with those of Nos. 7 to 9 of the conventional method. Further, among the comparative materials, No. 7 has high strength at high temperature because it contains Mo and Nb. However, since there is no addition of Cu and Ni, there is no rust at the end of the steel wire after sealing as in the method of the present invention. Cracking due to cracking was not prevented. Nos. 8 and 9 both have lower high-temperature strength than the method of the present invention. This is because there is no addition of Mo and Nb. Also,
Observation of cracks after sealing in glass
No cracks were observed in samples Nos. 6 to 6, indicating that the steel wire was extremely excellent in encapsulation.

[0023]

[Table 3]

The results of the water discharge test shown in Table 3 show that the high-temperature strength of the method of the present invention is excellent. It can be seen that the results correspond well with the results in Table 2 in which the high-temperature strength of a single steel wire was measured. Thus, it can be seen that the steel wire manufactured by the method of the present invention is a steel wire for glass reinforcement in which the encapsulation property, the edge corrosion prevention property and the high-temperature strength are higher and more stable than the conventional method.

Since these characteristics could not be achieved by the conventional method, the contribution of the method of the present invention to the related field is extremely large. In particular, since high-rise buildings are expected to increase more and more in the future, netted glass having high-temperature characteristics will be useful for preventing fire spread in a fire.

[0026]

The steel wire for reinforcing glass of the present invention has a long strength duration at high temperatures. By using the steel wire for glass reinforcement of the present invention, it has become possible to produce a netted glass having excellent high-temperature characteristics. In addition, the glass encapsulation manufacturing process is stable, and it is possible to manufacture meshed glass free from cracks and foaming. The netted glass using the steel wire of the present invention can exhibit the effect of reducing secondary disasters and fire spread when a fire occurs.

[0027]

Continuation of front page (56) References JP-A-2-77523 (JP, A) JP-A-52-113358 (JP, A) JP-A-53-94317 (JP, A) JP-A-4-285120 (JP, A) (A) JP-A-4-288919 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C21D 7/00-7/10 C03B 13/12 C03C 27/00-27/02 C22C 38/00-38/60

Claims (1)

(57) [Claims] C: 0.020% or less; Mn:
0.2-0.4%, Al: 0.003% or less,
Al% / N%: 1.3 or less, Mo: 0.1% to 0.5
%, Nb: 0.005% to 0.06%, Cr:
0.1-0.5%, Cu: 0.05-0.2% Ni
Is added to 1/3 to 1/2 of the amount of Cu, and the remainder is made by rolling a steel slab of steel components consisting of unavoidable impurities, then drawing to a predetermined size, and plating the steel wire surface in the final process A method for producing a glass reinforcing steel wire having excellent high-temperature characteristics, comprising: