JPH06172926A - Roll for rolling glass - Google Patents

Abstract

PURPOSE:To prevent the deformation caused by thermal expansion in a roll in the process of rolling and to provide a roll for rolling glass reducing the variation of the sheet thickness of the glass sheet to be rolled into a minimum. CONSTITUTION:The material of the base metal is constituted of, by weight, <=0.1% C, <=2.0% Si, <=2.0% Mn and 35.0 to 50.0% Ni or furthermore of <=25% Co (where Ni+Co=35 to 60%), moreover of one or >=two kinds among 0.2 to 1.0% Al, 0.5 to 2.0% Ti and 2.0 to 6.0% Nb and, at need, of one or two kinds of <=0.02% B and <=0.20% Zr, and the balance Fe with inevitable impurities, and the working face has a surface treated layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass rolling roll for a liquid crystal display device or the like, which requires high plate thickness accuracy.

[0002]

2. Description of the Related Art Generally, 13Cr is used for glass rolling rolls.
Martensitic stainless steel (JIS, SUS420
J2) etc. are used, and as an improved steel of this, 1.5%
The steels shown in JP-B-57-5871 and JP-B-58-2584, to which Ni of about the following level, W and Mo of the same level, or V of the same level, and W and Mo of the same level as described above are added. The steel proposed in JP-A-3-199346 in which a small amount of Nb is added in addition to V is
It is used as a roll material that has excellent strength when heated to high temperatures and is less prone to heat cracks.

[0003]

However, when a glass sheet is rolled by the above-mentioned conventional rolls, a variation in sheet thickness occurs in the product glass sheet, so that it is difficult to roll a glass sheet having a high sheet thickness accuracy. However, for a product that requires high plate thickness accuracy, there is a problem that a large number of maintenance steps are required in the post process. As a factor causing this plate thickness variation, the surface layer of the roll during rolling changes depending on the working conditions, but is heated up to 280 to 400 ° C (the temperature measured at the roll outlet), so the thermal expansion of each part of the roll Due to the difference in quantity,
It is considered that this is because the roll causes distortion such as a blur of the outer diameter. It is considered that the temperature of the local contact area with the glass to be rolled rises to about 600 ° C. estimated from the above temperature. The present invention has characteristics such as corrosion resistance, oxidation resistance and strength required as a glass rolling roll,
It is an object of the present invention to provide a glass rolling roll that prevents thermal distortion of the roll at high temperatures and suppresses variation in plate thickness.

The inventors of the present invention have assumed that the roll for glass rolling should be overcome in order to overcome the problem of hot deflection generated when conventional steel is used as a roll material and to reduce the maintenance work after rolling. Shows a low coefficient of thermal expansion in the temperature range
And with regard to the supposed improvement of crack resistance, corrosion resistance, and oxidation resistance, various candidate steels with added alloy components were defined,
Attempts were made to use these as roll materials for glass rolling. However, the inventors found that the corrosion resistance and the oxidation resistance were not directly satisfied, and that they could be supplemented by applying a surface treatment layer. As a result, during rolling, the roll has less hot deflection, and the formed glass is much flatter than that produced by conventional rolls, and rolls with practical performance such as corrosion resistance, oxidation resistance, and crack resistance are realized. We were able to.

That is, in the present invention, the base material is
C 0.1% or less, Si 2.0% or less, Mn 2.0% or less, Ni 3
5.0 to 50.0%, or even less than 25% Co, but Ni + C
35 to 60%, Al 0.2 to 1.0%, Ti 0.5 to 2.0%, Nb
A glass rolling roll characterized by comprising one or more of 2.0 to 6.0%, the balance Fe and unavoidable impurities, and having a surface treatment layer on the work surface, and a base material made of C by weight%. 0.1% or less, Si 2.0% or less, Mn 2.0%
Below, Ni 35.0-50.0%, or even Co 25% or less, but Ni + Co 35-60%, Al 0.2-1.0%, Ti 0.5
.About.2.0%, Nb 2.0 to 6.0%, 1 or 2 or more, B 0.02% or less and Zr 0.20% or less, 1 or 2 types, balance Fe and inevitable impurities, and a surface treatment layer is formed on the work surface. It is a glass rolling roll characterized by having.

[0006]

The glass-rolling roll usually has a hole for cooling water flow along its axis and is cooled by this hole. The temperatures of 600 ° C. and 280 to 400 ° C. are the temperatures of the contact local portion of the roll surface layer portion with the material to be rolled (glass) and immediately thereafter, and the inside of the roll is cooled as described above, As for it is not so hot. The alloys of the components specified by the present invention have the above-mentioned 13
It exhibits a coefficient of thermal expansion almost equal to that of Cr steel. For example, the average coefficient of thermal expansion of the material of the embodiment of the present invention described below from 300 ° C. to 400 ° C. is about 11 × 10 −6 powers / ° C.
12 × 10 minus 6 to the power of the conventional 13Cr steel (Comparative Example X) /
It is almost the same as ℃. However, as described above, most of the roll body is considered to be in a temperature range far lower than 300 ° C. Therefore, the steel having the composition range defined by the present invention has a low coefficient of thermal expansion during this period, and the coefficient of thermal expansion is Change is small, and therefore the thermal strain of the roll as a whole is extremely small despite the high temperature of the contact portion with the material to be rolled.

The reason why stainless steel is used as the roll material is that it is excellent in corrosion resistance and oxidation resistance.
With respect to this corrosion resistance and oxidation resistance, the material for a glass rolling roll of the present invention is inferior to stainless steel. Therefore, in order to improve the corrosion resistance, the oxidation resistance, and the wear resistance, the work surface of the roll is plated with a thickness of 10 μm or more, for example, Ni-B, hard Cr, etc., nitriding, etc. It is necessary to provide a surface treatment layer.

The reasons for limiting the components of the roll material for glass rolling of the present invention are shown below. C has a function of forming a carbide and suppressing the growth of crystal grains of the roll of the present invention. If it is too large, the age-hardening property is reduced and the thermal expansion amount is increased, so it is 0.
1% or less. Si is added as a deoxidizing agent and has the function of improving the oxidation resistance, but it is not necessary to add a large amount, and if it is too large, the hot workability deteriorates, so 2.0%.
Below. Mn, like Si, is added as a deoxidizing agent, but if it is too much, the coefficient of thermal expansion increases, so it was made 2.0% or less. Ni is known to reduce the amount of thermal expansion together with Co described later. In the present application, it is added for the same purpose,
Further, Ni is an important element having a function of forming an intermetallic compound with Al, Ti and Nb to increase the strength of the material of the present invention.
If it is less than 35.0% or more than 50.0%, the coefficient of thermal expansion is increased, which causes thermal strain of the roll, so 35.0%
It was set to ~ 50.0%.

Co functions to reduce the coefficient of thermal expansion together with Ni. However, in the case of a large amount, it makes it difficult for the intermetallic compound formed by Ni and Al, Ti, Nb to precipitate, and that Ni + Co is
When it exceeds 60%, the coefficient of thermal expansion rises, so Ni + Co is 35
It was set to ~ 60.0%. As described above, Al, Ti, and Nb impart strength as a roll material for glass rolling by forming and precipitating an intermetallic compound together with Ni, and one or more kinds thereof are added. . If it is too small, the effect of the above addition is not obtained, and if it is too large, the coefficient of thermal expansion is increased or segregation occurs in the matrix.
It was set to 0.5 to 2.0% and Nb 2.0 to 6.0%. B and Zr have the effect of strengthening the grain boundaries and enhancing the ductility of the alloy at high temperatures, and if necessary, one or two are added. But,
If added excessively, the hot workability will be deteriorated. Therefore, when added, they were limited to 0.02% and 0.20%, respectively.

Since the roll material of the present invention is inferior to stainless steel in corrosion resistance and oxidation resistance, surface treatment is carried out in order to improve these properties or further improve properties such as abrasion resistance. Provide layers. As the surface treatment layer, Ni,
Plating of Ni-B, hard Cr, etc., nitriding, etc. are simple and have a large effect, and in some cases it is effective to provide a surface layer by overlay thermal spraying or HIP.

[0011]

Example An alloy material having the chemical composition shown in Table 1 was melted.
The present invention materials A to I are 720 after the forging and the solution treatment at 950 ° C.
Aged at 620 ° C. The conventional material X is the alloy described in Japanese Patent Publication No. 58-2584, which has been quenched at 1030 ° C. and tempered at 720 ° C. Table 2 shows the measurement results of the average thermal expansion coefficients of the present invention materials A to I and the conventional material X from room temperature to each temperature. The materials A to I of the present invention have a smaller average coefficient of thermal expansion α _20-300 from room temperature to at least 300 ° C. than the conventional material X, and their changes are small. As a result, hot runout generated during glass rolling is significantly suppressed.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

[Table 3]

Table 3 shows materials A, B and E of the present invention and conventional material X.
The results of tensile tests at room temperature and 600 ° C are shown below. Inventive materials A, B, and E show 0.2% proof stress equal to or higher than the conventional material X at room temperature and excellent tensile strength, and at 600 ° C, 0.2% proof stress and tensile strength compared to the conventional material X. You can see that it is superior in strength. In addition, the precipitation strengthening elements Al, Ti,
Inventive material E, which contains a large amount of Nb, exhibits significantly superior strength as compared with inventive material B. Table 4 and Table 5
In addition, all of the present invention materials A, B and E and the conventional material X are Ni-
Investigate the evaluation result of the thickness variation of the product glass plate and the roll surface condition after using the 160mmφ × 1050L glass rolling roll with B plating (10μm thickness) at the speed of 5RPM for 400 hours. The result is shown. From Table 4, it can be seen that the roll of the present invention has a smaller amount of hot deflection than the conventional material X, and in particular, the deflection of the material E of the present invention to which Co is added is small and is 0.05 mm or less. In addition, it can be seen from Table 5 that the rolls A, B, E of the present invention and the conventional roll X are in good condition with respect to corrosion resistance and oxidation resistance without much difference.

[0016]

[Table 4]

[0017]

[Table 5]

[0018]

As described above, the glass-rolling roll of the present invention is added with one or more of Al, Ti and Nb, or one or two of B and Zr. It is a roll for precision glass rolling by combining a high-strength low thermal expansion material and a surface treatment layer applied to supplement its corrosion resistance and oxidation resistance, which can be reached with conventional rolls. It was possible to roll flat glass sheets, which was not possible. As a result, it has become possible to easily obtain a sheet glass product requiring high plate thickness accuracy for a liquid crystal display device or the like, which conventionally requires a large number of man-hours, as it is rolled.

Claims (2)

[Claims] 1. The base material is, by weight%, C 0.1% or less,
Si 2.0% or less, Mn 2.0% or less, Ni 35.0 to 50.0%, or further Co 25% or less, but Ni + Co 35 to 60%, Al 0.2 to 1.0%, Ti 0.5 to 2.0%, Nb 2.0 to 6.0% 1
A roll for glass rolling, comprising one or two or more kinds, the balance Fe and unavoidable impurities, and having a surface treatment layer on the work surface. 2. The base material is, by weight%, C 0.1% or less,
Si 2.0% or less, Mn 2.0% or less, Ni 35.0 to 50.0%, or further Co 25% or less, but Ni + Co 35 to 60%, Al 0.2 to 1.0%, Ti 0.5 to 2.0%, Nb 2.0 to 6.0% 1
A roll for glass rolling, comprising one or two or more, one or two of B 0.02% or less and Zr 0.20% or less, the balance Fe and unavoidable impurities, and having a surface treatment layer on the work surface.