JP3406726B2 - How to adjust the surface gloss of pure titanium sheet - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface gloss adjusting method for manufacturing a pure titanium thin plate having a low surface gloss by skin pass rolling. Pure titanium thin plates with low surface gloss have recently begun to be used for building materials.

[0002]

2. Description of the Related Art Conventional pure titanium thin plates are used only for their functional aspects as highly corrosion-resistant materials such as chemical reaction vessels, electrodes, heat exchangers, and welded pipes, and research and development on the appearance of the surface. It wasn't done. In recent years, it has begun to be used for building materials such as roofs and outer walls, and pure titanium thin plates having a low surface gloss like the stainless steel plates used conventionally have been demanded. Stainless steel thin plates are generally manufactured by a continuous annealing pickling method, and the surface thereof has a low gloss due to pickling. On the other hand, the pure titanium thin plate obtained by the vacuum annealing method has a high gloss before skin pass rolling, and it is necessary to devise a method for reducing the gloss.

Against this background, JP-A-63-10
Japanese Patent No. 3056 discloses a method for producing a pure titanium thin plate for building material use, which is a method for producing a pure titanium thin plate having a low surface gloss by performing pickling treatment. No specific method for pickling treatment has been proposed. The pickling treatment can obtain low glossiness, but its disadvantages are low yield and uneven glossiness. For example, a typical plate thickness for a roof is 0.4 mm, and if the amount of fusing on one side is 20 μm, it will be 10
The yield is reduced by%. On the other hand, if the amount of shaving is reduced, the surface condition before pickling is close and the temperature and the concentration of the pickling solution change in the plate width direction due to convection of the pickling solution, etc. It is easy for uneven gloss to occur between the part and the powder that has undergone a certain amount of fusing.

Further, the main purpose of the conventional skin pass rolling of a pure titanium thin plate is to correct a partial elongation such as an ear wave or a middle elongation, and the rolling reduction is 0.4 to 1.0%. Unlike a stainless steel sheet, even if rolling with a rough dull roll at such a reduction rate, even if the number of passes was increased, a pure titanium sheet with a sufficiently low surface gloss could not be built.

[0005]

Although the required surface glossiness varies, it is considered to be 100% or less when the stainless thin plate for building materials is used as a reference. As described above, the stainless thin plate is generally manufactured by the continuous annealing pickling method, and the glossiness of the material before the skin pass rolling is low, so that this target can be easily achieved without devising the skin pass rolling method. On the other hand, the pure titanium thin plate obtained by vacuum annealing or the like has a gloss of 200 to 300% before skin pass rolling.
It is a degree. In the present invention, the surface glossiness is 100% or less, that is, the glossiness reduction rate is 50% or more, and the number of passes is within 2 passes in order to carry out more efficiently. An object of the present invention is to provide a method for adjusting the surface glossiness of a pure titanium thin plate in which the glossiness of a product after rolling can be accurately predicted by controlling the rolling method based on the glossiness of a material before skin pass rolling.

[0006]

[Means and Actions for Solving the Problems] That is, the gist of the present invention is as follows. (1)
In a method for producing a pure titanium thin plate having a glossiness of y (%) by skin-pass rolling a material having a glossiness of x (%) before the skin pass rolling, the following formulas (1), (2) and (3) are used. Using the relationship, the reduction ratio r (%) per pass is selected in accordance with the above x (%), and finishing is performed by one-pass rolling using a rolling roll having a surface roughness Ra of 4.4 μm or more. A method for adjusting the surface glossiness of a pure titanium thin plate, characterized in that y (%) is adjusted to a predetermined value by

Y = x × (1−F (r) / 100) (1) F (r) = 1 + 24r-1.9r ² (2) 3 ≦ r ≦ 5 (3) (2) Skin pass rolling In the method for producing a pure titanium thin plate having a glossiness of y (%) by skin-pass rolling a material having a glossiness of x (%), the following equations (4), (5) and (6) are used. The reduction ratio r (%) per pass is selected according to the above x (%), and the surface roughness Ra is 2.8 μm.
A method for adjusting the surface glossiness of a pure titanium thin plate, which comprises adjusting the above-mentioned y (%) to a predetermined value by finishing by 2-pass rolling using the above-mentioned rolling rolls.

Y = x × (1−G (r) / 100) (4) G (r) = 24 + 24r-3.6r ² + 0.2r ³ (5) 1.5 ≦ r ≦ 5 (6) The present invention will be described in detail below. First, in the case of one-pass rolling, the surface roughness Ra of the rolling roll is set to 4.4 μm or more, as shown in FIG. This is because there is a large change in the degree of reduction in degree, that is, the glossiness after skin pass rolling tends to vary.

Next, in the case of two-pass rolling, the surface roughness Ra of the rolling roll is set to 2.8 μm or more, as shown in FIG. Insufficient reduction and surface roughness R of the rolling roll
This is because the change in the reduction rate of the glossiness is large with respect to the change in a, that is, the glossiness after skin pass rolling tends to vary.

Here, the reason why the surface roughness Ra of the rolling roll is increased is that the crystal structure of titanium is hcp, so that the anisotropy is large, and the sheet thickness is determined from the characteristics of the texture formed in the material before skin pass. This is because the deformation corresponding to the surface profile of the rolling roll becomes difficult unless the deformation resistance in the direction becomes large and the surface pressure and the strain amount are not large, that is, the surface roughness Ra of the rolling roll is not large.

Further, when a titanium material is rolled, the roll surface is more likely to be worn and the surface roughness Ra of the rolling roll is more likely to be reduced than in the case of ordinary steel or stainless steel. This phenomenon is because titanium easily adheres to the iron alloy, which is the material of the roll, and it is necessary to set the surface roughness of the rolling roll to a large value. It is not necessary to specify the upper limit of the surface roughness of the rolling roll, but in the method of blasting a normal grid, R
The limit of a is about 10 μm.

Next, in the case of one-pass rolling, the reduction ratio per pass is set to 3.0% or more, as shown in FIG.
If it is less than 3.0%, the surface roughness Ra of the rolling roll is 4.4.
Even if it is more than μm, the reduction rate of glossiness is 50% in one pass.
This is not possible, and as a result, as shown in FIG. 1, the glossiness of the product after skin pass rolling cannot be 100% or less. On the other hand, when the rolling reduction is 3.0% or more, the reduction rate of the glossiness with one pass can be 50% or more when the surface roughness Ra of the rolling roll is 4.4 μm or more. Here, F (r) is an expression that approximates the number of passes, the roughness Ra of the rolling roll, and the reduction rate of glossiness in the range of the reduction rate among the experimental data of FIG.

Next, in the case of two-pass rolling, the reduction ratio per pass is set to 1.5% or more, as shown in FIG.
If it is less than 1.5%, the surface roughness Ra of the rolling roll is 2.8.
Even if it is more than μm, the reduction rate of glossiness is 50% in 2 passes.
This is not possible, and as a result, as shown in FIG. 1, the glossiness of the product after skin pass rolling cannot be 100% or less. On the other hand, when the reduction rate per pass is set to 1.5% or more, the reduction rate of the glossiness when the number of passes is two is 50% or more when the surface roughness Ra of the rolling roll is 2.8 μm or more. Can be achieved. Where G (r)
2 is an expression that approximates the number of passes, the roughness Ra of the rolling roll, and the reduction rate of glossiness in the range of reduction rate among the experimental data of FIG.

Here, as described above, it is necessary to increase the reduction rate because the pure titanium thin plate has a high glossiness of the material before the skin pass, and is more difficult to deform in the plate thickness direction than the stainless thin plate. This is because it is easy to deform (width shrinks) in the width direction, and the surface roughness of the roll is difficult to transfer to the plate. Furthermore, according to the method of the present invention, as shown in FIGS. 1 and 2, even when the roll roughness Ra decreases during rolling,
The change of the reduction rate of the glossiness is small with respect to the change of the roll roughness Ra, so that the uniform glossiness can be obtained for the length of the dull rolling. Further, if the glossiness of the material before the skin pass rolling is grasped, the reduction ratio can be controlled to easily obtain the target glossiness of the product.

Next, the reduction rate per pass in the skin pass rolling is set to 5% or less. When it exceeds 5%, the reduction rate of the glossiness starts to saturate, and on the other hand, there is a risk of buckling in the plate width direction. Because there is. In the skin pass rolling, in order to secure the shape of the titanium thin plate, it is necessary to increase the tension as the rolling reduction is increased.
Titanium sheet with large value and small Young's modulus is
When the plate thickness is thin, there is a risk of buckling in the plate width direction, so the rolling reduction was defined as 5% or less.

The relationship between the material and the reduction rate of glossiness is soft, that is, among pure titanium, it is JIS type 1 and the grain size after annealing is large, and it is hard, that is, JIS2.
No difference was observed between the seeds and those having a small grain size after annealing. Here, the surface roughness Ra of the rolling roll is the roughness as shot. Usually, dummy rolling is performed before the rolling to stabilize the surface roughness, and thereafter the surface roughness Ra of the rolling roll is reduced by about 15 to 20%.

Here, the reduction rate of the glossiness is a value expressed by (glossiness of the original plate-glossiness after dull rolling) / glossiness of the original plate in percentage. Here, the glossiness of the plate after the dull rolling is the glossiness of the original plate × (1−glossiness reduction rate / 100).
Here, the rolling reduction is a value converted from the elongation.

[0018]

EXAMPLES Tables 1 and 2 (continued from Table 1) show examples and evaluation results of the method for adjusting the surface glossiness of a pure titanium thin plate of the present invention. The test material is a pure titanium JIS Class 1 cold-rolled annealed plate having a plate thickness of 0.4 mm. The surface has a metallic luster, and the average surface roughness Ra in the L direction and the C direction is 0.16 to 0.24.
μm, and the glossiness was 200%, 250%, and 300%. Here, the glossiness is an average value in the L direction and the C direction measured by Gs (45 degrees) of JIS standard Z-8741. The surface of the rolling roll is # 10, # 24, # 40,
Blasting four kinds of grids of # 80 and roughening until there is no flat part, and the surface roughness Ra of each is 6.7 μm.
m, 4.4 μm, 2.8 μm, and 1.3 μm.

Surface roughness Ra of the rolling roll in skin pass rolling, number of passes, reduction ratio per pass, gloss of the plate before rolling, expected value of gloss of the plate after rolling according to the present invention, after rolling Tables 1 and 2 show the difference between the glossiness of the plate and the glossiness of the plate after rolling and the expected value. The evaluations were the efficiency of the rolling method (within 2 passes being good), the low glossiness of the product after skin pass rolling (100% or less was good), and the small difference from the expected glossiness (prediction). + 5% or less and -5% or more of the value were regarded as good).

[0020]

[Table 1]

[0021]

[Table 2]

Nos. 1 and 2 shown in Tables 1 and 2 are examples of the present invention. 4-1
0 and No. Nos. 12 to 21 show remarkable effects. On the other hand, in Comparative Example No. 1 and 11 do not have a sufficiently low gloss. In addition, No. In Nos. 2 and 3, the glossiness prediction accuracy is poor. Furthermore, No. Nos. 22 to 25 are methods in which the roughness Ra of the rolling roll is increased, but the rolling reduction is as small as 1%, so that the efficiency of the rolling method or the low glossiness of the product after skin pass rolling is insufficient. It can be seen that it is.

[0023]

According to the present invention, if the surface glossiness of the material before skin pass rolling is known, the surface glossiness after skin pass rolling can be accurately predicted, and a pure titanium thin plate having a sufficiently low and predicted value glossiness can be obtained. Can be built efficiently.

[Brief description of drawings]

FIG. 1 is a diagram showing the relationship between the rolling reduction per pass and the glossiness for each surface roughness Ra of a rolling roll and the number of passes (when the glossiness of a material before skin pass rolling is 200%).

FIG. 2 is a diagram showing a relationship between a rolling reduction per pass and a gloss reduction rate for each surface roughness Ra of a rolling roll and the number of passes.

FIG. 3 is a diagram showing the relationship between the surface roughness Ra of a rolling roll and the reduction rate of glossiness for each reduction rate and the number of passes.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kosho Nishida 3434 Shimada, Hikari-shi, Shimadzu, Nippon Steel Corporation (72) Inventor Masaki Masaki, 2-6-3 Otemachi, Chiyoda-ku, Tokyo Issue: Nippon Steel Co., Ltd. (56) Reference JP 62-267458 (JP, A) JP 63-128159 (JP, A) JP 2-170957 (JP, A) (58) Survey Areas (Int.Cl. ⁷ , DB name) B21B 1/00-3/02 B21B 27/00

Claims (2)

(57) [Claims] 1. A method for producing a pure titanium thin plate having a glossiness of y (%) by skin-pass rolling a material having a glossiness of x (%) before skin-pass rolling, comprising the following (1), (2),
Using the relationship of the equation (3), the rolling reduction r (%) per pass is selected in correspondence with the x (%), and the rolling roughness having a surface roughness Ra of 4.4 μm or more is used. A method for adjusting the surface glossiness of a pure titanium thin plate, characterized in that the y (%) is adjusted to a predetermined value by finishing by pass rolling. y = x × (1-F (r) / 100) (1) F (r) = 1 + 24r-1.9r ² (2) 3 ≦ r ≦ 5 (3) 2. A method for producing a pure titanium thin plate having a glossiness of y (%) by skin-pass rolling a material having a glossiness of x (%) before the skin pass rolling, the method comprising the following (4), (5),
Using the relationship of the formula (6), the rolling reduction r (%) per pass is selected in correspondence with the x (%), and the rolling roughness having a surface roughness Ra of 2.8 μm or more is used. A method for adjusting the surface glossiness of a pure titanium thin plate, characterized in that the y (%) is adjusted to a predetermined value by finishing by pass rolling. y = x × (1−G (r) / 100) (4) G (r) = 24 + 24r-3.6r ² + 0.2r ³ (5) 1.5 ≦ r ≦ 5 (6)