KR101230081B1 - Pickling method of titanium slab and titanium slab manufactured using the same - Google Patents

Abstract

The present invention relates to a method for pickling titanium plates that can be pickled using existing stainless steel equipment and titanium plates manufactured using the same.
According to the present invention, in the pickling process of the titanium plate passed through the annealing step, the pickling method of the titanium plate comprising at least one polishing step performed by a brush between the annealing step and the pickling step or in the pickling step, and Provided is a titanium plate produced using this.

Description

Pickling method of titanium slab and titanium slab manufactured using same {Pickling method of titanium slab and titanium slab manufactured using the same}

The present invention relates to a titanium plate pickling method and a titanium plate manufactured using the same, and more particularly, to a pickling method of a titanium plate that can be picked using a conventional stainless steel equipment and a titanium plate manufactured using the same will be.

Titanium materials, which have excellent mechanical properties and corrosion resistance, have various applications, and the development of titanium materials is highly profitable.

While the demand for titanium materials increases, the current titanium materials used in Korea depend on imports, and the development and production of titanium materials has high technical barriers, making it difficult for latecomers to enter the market.

In addition, the development and production of titanium materials can utilize the existing stainless steel equipment, so it is possible to enter new markets of titanium material development with minimal investment. In addition, quality control technology of stainless steel, which has been accumulated for a long time, can also be utilized.

However, there is a problem in applying a general stainless steel pickling method due to the dense scale formation of titanium dioxide (TiO ₂ ) present in the titanium material.

The present invention relates to a method for pickling titanium plates and titanium plates manufactured using the same, and more particularly, to provide a method for pickling titanium plates that can be picked using existing stainless steel equipment.

According to an aspect of the present invention, in the pickling process of the titanium plate passed through the annealing process, the titanium plate comprising at least one polishing step performed by a brush between the annealing process and the pickling process or in the pickling process. Pickling methods are provided.

In the polishing step, the brush may be a heavy brush or an abrasive brush.

In the polishing step, the titanium plate may be pickled by sulfuric acid.

In the polishing step, the titanium plate may be pickled by a mixed acid of hydrofluoric acid and nitric acid.

The number of revolutions of the heavy brush and the number of revolutions of the aggressive brush may range from 980 rpm to 1020 rpm.

Here, the pickling process may be repeated at least twice.

Here, the scale may further include a descale step between the annealing process and the pickling process to remove the scale of the titanium plate surface by a scale breaker.

According to another aspect of the present invention, there is provided a titanium sheet made of at least 99.5% by weight of titanium and unavoidable impurities and comprising at least one polishing step performed by a brush between the annealing process and the pickling process or in the pickling process.

According to the present invention, it is possible to provide a method for pickling titanium plates that can pickle using existing stainless steel equipment without constructing a titanium plate pickling line which requires enormous cost.

1 is a cross-sectional view schematically showing a pickling process of a titanium sheet according to an embodiment of the present invention.
2A to 2E are enlarged photographs of the surface of the titanium sheet according to the comparative example of the present invention.
Figure 3 is an enlarged photograph of the surface of the titanium plate according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention and other matters required by those skilled in the art will be described in detail with reference to the accompanying drawings. However, the present invention may be embodied in various different forms within the scope of the claims, and thus the embodiments described below are merely exemplary, regardless of expression.

In describing the present embodiment, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. It should be noted that the same elements in the drawings are represented by the same reference numerals and symbols as much as possible even though they are shown in different drawings. In addition, the thickness or size of each layer in the drawings may be exaggerated for convenience and clarity of description and may be different from the actual layer thickness or size.

The present invention relates to a method for pickling titanium plates that can be pickled using existing stainless steel equipment, and to titanium plates manufactured using the same, having excellent surface quality without building a costly titanium plate pickling line. We want to find process conditions that can provide titanium plates.

1 is a cross-sectional view schematically showing a pickling process of a titanium plate according to an embodiment of the present invention, Figures 2a to 2e is an enlarged photograph of the surface of the titanium plate according to a comparative example of the present invention, Figure 3 An enlarged photograph of the surface of the titanium plate according to the embodiment.

Referring to FIG. 1, the titanium material 10a in the wound state is unwound to form a titanium material strip 10a ′.

Next, the titanium material strip 10a 'is annealed in the annealing furnace 20. The annealing process is preferably performed in a temperature range of 750 ℃ to 850 ℃, the temperature of the annealing process is not limited thereto.

Here, when the temperature in the annealing process is less than 750 ° C., there is a problem of poor workability during cold rolling because it is micro-annealed and no recrystallization softening occurs. The problem arises that the oxide layer removal load and error rate are lowered.

In addition, although not shown, a process of welding the plurality of titanium strips 10a 'using a welder may be further included for the continuous annealing process.

Next, a scale breaker can be used to make it easy to remove the scale attached to the surface of the titanium strip 10a '.

Subsequently, a shot blaster using a plurality of shot balls having a fine particle diameter of about 0.1 mm may be applied to the surface of the titanium strip 10a ', but in the embodiment of the present invention, Even if such a step is not applied, since the pickling can be completely performed only by the first polishing step 31a, the second polishing step 31b, or the third polishing step 31c to be described later, the above step can be omitted. In general, the shot blaster process as described above may cause cracking of the surface or to expand the cracks that have already occurred, and the subsequent pickling process 30 may be easier with the cracks or the expanded cracks thus generated. It has an effect.

Next, the titanium strip 10a 'is moved to perform the first polishing step 31a. Thereafter, the first pickling process 35a is performed to immerse or clean the titanium strip 10a 'with sulfuric acid. Next, after the titanium material strip 10a 'is moved to perform the second polishing step 31b, the second pickling process 35b for immersing or cleaning the titanium material strip 10a' with a mixed acid consisting of hydrofluoric acid and nitric acid is performed. ). Finally, a third pickling process of moving the titanium strip 10a 'to perform a third polishing step 31c and then immersing or cleaning the titanium strip 10a' with a mixed acid consisting of hydrofluoric acid and nitric acid ( 35c).

In the first to third pickling processes 35a, 35b and 35c, the titanium strip 10a 'is immersed or washed by a strong acid such as sulfuric acid or a mixed acid consisting of hydrofluoric acid and nitric acid, but the strong acid or mixed The type of acid is not limited thereto.

In the first to third polishing processes 31a, 31b, and 31c, the rotation speed of the brushes 33a, 33b, and 33c may range from 980 rpm to 1020 rpm. Here, if the number of rotations of the brushes 33a, 33b, 33c is less than 980 rpm, the surface grinding force is weak and there is a problem that the pickling property is low, and the number of rotations of the brushes 33a, 33b, 33c is more than 10200 rpm. The back surface of the titanium strip (10a ') is a scratch problem occurs because there is a bad problem. Here, the first to third pickling processes (35a, 35b, 35c) is preferably repeated at least twice, but the number of repetitions is not limited to this may be changed to various conditions according to the process conditions.

In addition, in the first to third polishing processes 31a, 31b, and 31c, the brushes 33a, 33b, and 33c may be heavy brushes or abrasive brushes as necessary. have.

Next, the titanium strip 10b 'according to the embodiment of the present invention, which has passed through the annealing and pickling process 30 described above, may be rolled using a skin pass mill (SPM). According to the rolling process, the surface of the titanium strip 10b 'may be rolled by about several% to give gloss to the surface.

According to the embodiment of the present invention provided as described above, the titanium material strip 10b 'having improved surface quality is again wound and becomes a titanium material 10b in a wound state.

Here, in the Examples and Comparative Examples of the present invention, the target steel grade is a titanium material 10a composed of at least 99.5% by weight of titanium and unavoidable impurities.

Comparative example  And conduct Yes

Hereinafter, the present invention will be described in detail with reference to Table 1 and FIGS. 2A to 3.

Table 1 shows the results applied to the actual production line according to the comparative example and the invention example of the present invention.

When applied to the actual line section as shown in Table 1, perfect pickling was performed in Example 1 and Comparative Example 1 that went through the first to third polishing processes (31a, 31b, 31c). However, in the comparative example 1, there existed a problem which the slip defect by the skin pass mill process generate | occur | produces on the surface.

In Comparative Examples 2 to 5, which did not pass through the first to third polishing processes 31a, 31b, and 31c, scales remained on the surface and were not pickled.

2A to 2E are enlarged photographs of the surface of the titanium plate according to the comparative example of the present invention, and FIG. 3 is enlarged photographs of the surface of the titanium plate according to the embodiment of the present invention.

FIG. 2A shows the results of pickling titanium plates of Comparative Example 1 fabricated from 100 X 150 mm specimens under operating conditions of scale breaker / heavy brush brushes 33a / abrasive brushes 33b and 33c / skin pass mills. FIG. to be. In the shape shown in the photograph, pickling was the most, but there was a problem that a slip defect was generated on the surface by a skin pass mill process.

Figure 2b is a result of pickling the titanium plate of Comparative Example 2 made of a specimen size of 100 X 150 mm in the scale breaker / abrasive brush (33b, 33c) / skin pass mill operating conditions. From the shape shown in the picture, it was found that pickling was not performed.

Figure 2c is a result of pickling the titanium plate of Comparative Example 3 made of a specimen of size 100 × 150 mm under the operating conditions of the scale breaker / abrasive brush (33b, 33c). From the shape shown in the picture, it was found that pickling was not performed.

Figure 2d is a result of pickling the titanium plate of Comparative Example 4 made of a specimen of 100 X 150 mm size under the operating conditions of the abrasive brush (33b, 33c). From the shape shown in the picture, it was found that pickling was not performed.

FIG. 2E shows the results under the condition that mechanical pickling is not performed on the titanium sheet 10a of Comparative Example 5 manufactured from a specimen having a size of 100 × 150 mm. From the shape shown in the picture, it was found that pickling was not performed.

On the other hand, Figure 3 is a result of pickling twice the titanium plate 10a of the embodiment produced by the specimen of the size 100 × 150 mm as the embodiment. From the shape shown in the photograph, it was found that the titanium plate of the example was pickled under optimum conditions.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be apparent to those skilled in the art that various modifications may be made without departing from the scope of the present invention.

10a: titanium plate 10a ': titanium strip
20: annealing furnace 30: pickling process
31a: first polishing step 31b: second polishing step
31c: Third polishing step 33a, 33b, 33c: Brush
35a: first pickling process 35b: second pickling process
35c: Third pickling process 10b: Titanium material
10b ': Titanium strip

Claims (8)

In the pickling process of the titanium plate which passed the annealing process,
At least one polishing step performed by a brush between the annealing process and the pickling process or in the pickling process, wherein the pickling process is repeated at least twice,
The polishing step includes first to third polishing processes,
The pickling process includes a first to third pickling process,
After passing through the annealing process, the titanium plate is sequentially subjected to the first polishing step, the first pickling step, the second polishing step, the second pickling step, the third polishing step and the third pickling step,
The titanium plate is a method of pickling titanium plate made of titanium 99.5% by weight or more and inevitable impurities.
The method of claim 1,
In the polishing step,
The brush of the titanium plate pickling method, characterized in that the heavy brush (heavy brush) or an abrasive brush (abrasive brush).
The method of claim 2,
In the polishing step,
The titanium plate is pickling method of the titanium plate, characterized in that pickling by sulfuric acid.
The method of claim 2,
In the polishing step,
The titanium plate is pickling method of the titanium plate, characterized in that pickling by a mixed acid of hydrofluoric acid and nitric acid.
The method of claim 2,
The number of revolutions of the heavy brush and the number of revolutions of the aggressive brush is a method of pickling titanium plate, characterized in that the range of 980 rpm to 1020 rpm.
delete The method of claim 1,
Between the annealing step and the pickling step,
And descaling the scale of the titanium sheet surface by a scale breaker.
delete

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