JP2000313945A - Steel sheet for heat shrink band, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steel sheet for heat shrink band, capable of maintaining magnetic shielding property while keeping strength and capable of attaining a color cathode-ray tube minimal in color slippage, and its manufacturing method. SOLUTION: The steel sheet for heat shrink band has a chemical composition containing, by weight, <=0.005% C, <=0.1% Si, 0.1-2% Mn, <=0.15% P, <=0.02% S, <=0.08% sol.Al, <=0.005% N, 0.02-0.06% Ti, and 0.0003-0.005% B, and further, the product of magnetic permeability in a magnetic field of 0.3 Oe and sheet thickness (mm), in a state after shrinkage fit, is regulated to >=350, preferably >=400. This steel sheet for heat shrink band can be manufactured by subjecting a steel with the above chemical composition to hot rolling and cold rolling and then to annealing at 800-900 deg.C or further subjecting the resultant steel sheet to overaging treatment at 250-500 deg.C and then to temper rolling at <=0.5% rolling rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel plate for a band for a heat shrink band for tightening the periphery of a panel in a color cathode ray tube such as a television and a method for manufacturing the same.

[0002]

2. Description of the Related Art In a color cathode ray tube, the inside of the tube is 1.0 × 10
^Due to the high vacuum of about ^-7 Torr, it is necessary to take measures to prevent deformation of the panel surface and inner explosion of the tube. From such a viewpoint, a heat shrink band made of a steel sheet formed into a band shape is heated and expanded for several seconds to several tens of seconds in a temperature range of about 400 ° C. to about 600 ° C., fitted into a color cathode ray tube glass panel, and cooled and shrunk. The deformation of the panel surface is corrected by a so-called shrink fit process for applying tension.

Further, such a heat shrink band also has a function of shielding the terrestrial magnetism as well as the internal magnetic shield, and the displacement of the landing position of the electron beam on the phosphor screen due to the terrestrial magnetism, that is, the color displacement occurs. It has a function to prevent it from doing so. For such a purpose, mild steel has conventionally been used as a material for the heat shrink band.

Japanese Patent Application Laid-Open No. Hei 10-208670 proposes a method of manufacturing a heat shrink band having a sufficient tension for correcting deformation of a panel surface due to air pressure and having a sufficient magnetic shielding property.

In this technique, C ≦ 0.005% by weight, 2.0%
% ≦ Si ≦ 4.0%, 0.1% ≦ Mn ≦ 1.0%, P ≦ 0.2%, S
≦ 0.020%, Sol. Al ≦ 0.004% or 0.1% ≦ So
l. Hot rolling and / or cold rolling a steel containing Al ≦ 1.0% and N ≦ 0.005%, annealing at 700 to 900 ° C., and lightly cooling at a cooling pressure rate of 3 to 15%. And As a result, the magnetic permeability μ at 0.3 Oe after heating and cooling after the light-cooling step becomes μ ≧ 250, and the yield stress YS becomes YS ≧ 40 kgf / mm ² .

[0006]

In the prior art,
Although mild steel was used for the heat shrink band steel sheet, the magnetic permeability at a geomagnetic level (about 0.3 Oe) was about 200, and the magnetic shielding properties were not sufficient. Therefore, for color misregistration due to terrestrial magnetism,
Complicated steps such as adjusting the position of the phosphor screen have been required.

In the technique described in Japanese Patent Application Laid-Open No. 10-208670, there is an effect that the magnetic permeability is improved by increasing the amount of Si. However, since about 3% is added, the strength is too high and YS < When 40 kgf / mm ² is required, there is a problem that it is difficult to respond.

The present invention has been made in view of such circumstances, and a color cathode ray tube which maintains a sufficient magnetic shielding property while maintaining a level of strength which does not cause a problem in explosion-proof property, and in particular, has a small color shift. It is an object of the present invention to provide a heat shrink band steel sheet that can be realized and a method for manufacturing the same.

[0009]

The above object is achieved by the following invention. In the first invention, as a chemical component, by weight%, C: 0.005% or less, Si: 0.1% or less, Mn: 0.1% or more
2% or less, P: 0.15% or less, S: 0.02% or less, sol. Al: 0.
08% or less, N: 0.005% or less, Ti: 0.02% or more and 0.06% or less, B: 0.0003% or more and 0.005% or less, and the magnetic permeability and plate thickness (mm) in a 0.3 Oe magnetic field after shrink fitting. ) Is 350 or more.

The present invention has been made as a result of intensive studies to solve the above problems. During the review process,
The following findings were obtained. (1) When Si is added in excess of 0.1%, the strength of the band at a high temperature becomes too high, so that the adhesion between the band and the panel is reduced and the geomagnetic drift property is deteriorated. (2) In order to maintain high magnetic permeability after shrink fitting, Ti
It is effective to add carbides and B to form carbides and nitrides and reduce the amount of solute C and solute N. (3) The amount of Si in the material of the steel plate for heat shrink band should be 0.
In the case of 1% or less, the external magnetic field strength of the geomagnetic level is 0.3
Product of permeability μ (relative permeability) in Oe and plate thickness t (mm):
When μ × t is 350 or more, color shift can be improved.

Based on these findings, a detailed study was conducted to determine chemical components and various characteristic values. First, the reasons for limiting each chemical component will be described.

C: C is an element that contributes to the strengthening of the steel sheet, but is not preferable for the magnetic permeability. To prevent this adverse effect, the content of C is 0.005% or less, preferably 0.0%.
03% or less, more preferably 0.002% or less.

[0013] Si: In the present invention, even if it is not added or added as a deoxidizing agent, as described above,
0.1% or less.

Mn: Mn is effective in improving hot ductility,
Further, it is an element that also contributes to an increase in the strength of the steel sheet due to solid solution strengthening. Therefore, the lower limit is set to 0.1%. On the other hand, Mn content is 2%
If it exceeds, the magnetic permeability will deteriorate.
2% or less. Note that within these specified ranges, the Mn content may be selected according to a desired strength level.

P: P is an element contributing to the strengthening of the steel sheet, and may be added as necessary. However, 0.15
%, The steel sheet becomes brittle and causes problems such as coil breakage during cold rolling. Therefore, the content is specified to be 0.15% or less.

S: S is unfavorable for both hot ductility and magnetic permeability, and its content is specified to be 0.02% or less from the viewpoint of not adversely affecting them.

Sol.Al: Since Al deteriorates workability,
To prevent this effect, its content is specified to be 0.08% or less.

N: Like C, N is an element contributing to the strengthening of the steel sheet, but is not preferable for the magnetic permeability. To prevent this adverse effect, the content is made 0.005% or less, preferably 0.003% or less. .

Ti: Ti, together with B, is one of the most important components in the present invention. By adding Ti, solid solution N can be fixed as nitride or solid solution C can be fixed as carbide and the like, and the change of the material due to solid solution C and solid solution N with time can be suppressed. However, excessive addition adversely affects the magnetic permeability, so the content should be 0.02
% To 0.06%, preferably 0.03% to 0.05%.

B: B is one of the most important components of the present invention together with Ti. B has the effect of improving the brittleness of the steel sheet and also has the property of fixing solid solution N.
% Or more. However, excessive addition causes the ductility of the steel sheet to deteriorate, so the content is specified to be 0.005% or less, preferably 0.002% or less, and more preferably 0.0010% or less.

Next, as a definition of the characteristic value, the product of the magnetic permeability and the plate thickness (mm) in a magnetic field of 0.3 Oe after shrink fitting is set to 350 or more. This is determined as a condition under which the color shift (drift amount of the electron beam) is significantly lower than that of the related art from the relationship between the color shift and the magnetic permeability as described later.

The heat shrink band may be plated from the viewpoint of corrosion resistance. Even in this case, if the characteristics before plating satisfy the range of the present invention,
A predetermined characteristic is obtained.

According to a second aspect of the present invention, 0.3 O
e. A product for a heat shrink band according to the first invention, wherein the product of the magnetic permeability and the thickness (mm) in the magnetic field of e is 400 or more.

According to the present invention, by further limiting the product of the magnetic permeability and the plate thickness, the color misregistration can be reduced by 5% or more as compared with the prior art.

According to a third invention, a steel having the chemical composition of the first invention is hot-rolled, subsequently cold-rolled,
Producing a steel sheet for a heat shrink band, wherein the obtained steel sheet is annealed in a temperature range of 800 ° C or more and 900 ° C or less, or after this annealing, a temper rolling is further performed at a rolling reduction of 0.5% or less. Is the way.

According to the present invention, as one method for securing magnetic permeability, annealing at 800 ° C. or more and 900 ° C. or less is performed. The range of the annealing temperature is determined from experimental results described later, and a high magnetic permeability can be obtained in this temperature range. Below the lower limit of the annealing temperature,
If the recrystallization and subsequent grain growth are insufficient, the magnetic permeability is low. If the upper limit is exceeded, the crystal passes through the transformation point and the crystal grains are refined to lower the magnetic permeability.

After annealing, it is necessary not to perform temper rolling, or even if temper rolling is performed, the rolling reduction must be 0.5% or less. This is because when the rolling reduction of the temper rolling exceeds the upper limit, the magnetic permeability decreases due to an increase in distortion introduced with the temper rolling.

A fourth aspect of the present invention is the heat shrink band according to the third aspect, wherein the over-aging treatment is performed in a temperature range of 250 ° C. or more and 500 ° C. or less after annealing or between annealing and temper rolling. This is a method for producing a steel sheet for use.

The result of the study that this invention is more suitable if the overaging treatment, which is the precipitation treatment of carbide, is carried out in the temperature range of 250 to 500 ° C., following the 800 ° C. to 900 ° C. annealing of the third invention. It was made based on.

Thus, a steel sheet suitable for a heat shrink band having a high magnetic permeability and a small geomagnetic drift can be obtained. Hereinafter, the details of the study leading to the invention will be described.

1. Relationship between Si content and geomagnetic drift Samples were as follows: C: 0.003%, Mn: 0.9%, P: 0.07%, S: 0.007
%, Sol. Al: 0.03%, N: 0.002% or less, Ti: 0.04%,
B: A steel containing 0.0010% and Si: varied from 0.01% to 0.2% was used. The steel was hot rolled to 2.5 mmt after laboratory melting, then cold rolled to 1.0 mmt, annealed at 850 ° C for 90 seconds, and overaged at 450 ° C for 2 minutes. The steel sheet is processed into a band of a predetermined shape without temper rolling,
After heating to 500 ° C, it was fitted into a 29-inch TV cathode ray tube panel, and the geomagnetic drift property was evaluated. FIG. 1 is a diagram showing the relationship between the amount of Si in steel and the geomagnetic drift.

Bh and Bv on the vertical axis indicate the drift amount of the landing point of the electron beam. In particular,
With the vertical magnetic field of 0.35 Oe and the horizontal magnetic field of 0.3 Oe applied to the CRT, the CRT is rotated 360 °, and the displacement (landing error) of the landing point of the electron beam with respect to the reference point is measured. The value of the to-peak was taken as the horizontal drift amount Bh.

The horizontal magnetic field is set to 0 Oe, and the vertical magnetic field is set to 0 Oe.
The landing error when changing from 0 Oe to 0.35 Oe was measured as the vertical drift amount Bv. The drift amount of the landing error on the vertical axis is
The value is shown as a relative value when the value of 0.1% is set to 1.

As shown in FIG. 1, the geomagnetic drift property is such that the Si content is equal to 0.
Good properties were shown up to 1%, but there was a tendency to deteriorate when it exceeded 0.1%. Normally, it was expected that the magnetic permeability would increase with an increase in the Si content, so that the geomagnetic drift property would be improved. Therefore, this phenomenon was examined in further detail.

As a result, it was found that when the Si content was more than 0.1%, the adhesion between the panel and the band was reduced, and a gap was generated between the panel and the band. It is considered that such a gap becomes a factor of deteriorating the magnetic shielding property, and thus the geomagnetic drift property is lowered. Si
It is not clear why the adhesion between the panel and the band decreases when the amount increases, but it is thought that the adhesion at the time of shrink-fit shrinkage decreased and a gap was formed because Si increased the high-temperature strength. Can be Based on the above results, the amount of Si is set to 0.1% or less.

2. Relationship between magnetic permeability and color misregistration C: 0.002%, Si: 0.02%, Mn: 0.8%, P:
0.07%, S: 0.006%, sol. A steel having a composition of Al: 0.04%, N: 0.002% or less, Ti: 0.04%, and B: 0.0008% was melted in a laboratory and then hot-rolled to 3.2 mmt. Then 0.8m
After cold rolling to mt ~ 1.6mmt, annealing at 850 ° C or 870 ° C for 90 seconds, overaging at 450 ° C for 2 minutes, and then subjecting the band to a predetermined shape without temper rolling Processed to.

After heating the processed band at 500 ° C. for 60 seconds, it was fitted into a 29-inch TV cathode ray tube panel, and the geomagnetic drift property was evaluated. Here, C:
0.04%, Si: 0.01%, Mn: 0.21%, P: 0.015%, S: 0.0
13%, sol. Al: 0.02%, N: 0.002% composition steel plate,
The same examination was carried out for a material subjected to temper rolling of 1% after the overaging treatment.

FIG. 2 is a diagram showing the relationship between color misregistration and magnetic permeability. The horizontal axis in the figure is the external magnetic field equivalent to geomagnetism 0.3 O
e shows the product μ × t of the magnetic permeability μ and the plate thickness t (mm) at e, where Bh and Bv on the vertical axis represent the horizontal of the landing point of the electron beam,
It shows the amount of drift in the vertical direction. The magnetic permeability μ was measured after performing a heat treatment at 500 ° C., which is equivalent to shrink fitting, for 60 seconds on a ring test piece taken from the annealed plate before shrink fitting.

The drift amount of the landing error on the vertical axis is shown as a relative value when the value of the above-mentioned conventional material is set to 1.

FIG. 2 shows that the ratio of Bh and Bv to the conventional material is about 1.0 at μ × t up to about 300, which is about the same value as that of the conventional material, but tends to be significantly reduced from 350. . From this, it can be seen that the color shift due to terrestrial magnetism is improved by increasing μ × t, and the value is 350 or more, which is superior to the conventional material. Further, when μ × t is 400 or more, the ratio of Bh and Bv to the conventional material becomes 0.95 or less, and the color shift can be reduced by 5% or more compared to the conventional technology.

3. Relationship between pressure regulation rate and magnetic permeability Samples: C: 0.003%, Si: 0.01% or less, Mn: 1.0%, P:
0.08%, S: 0.005%, sol. Al: 0.04%, N: 0.002% or less, Ti: 0.05%, B: 0.0007%. After the steel was melted in the laboratory, it was hot-rolled to 2.8 mmt, cold-rolled to 1.0 mmt, and then annealed at 850 ° C for 90 seconds followed by 450 ° C for 2 seconds.
The steel sheet was manufactured by subjecting it to an overaging treatment for 1 minute and then to temper rolling at a rolling ratio of 0 to 2%. The measurement of the magnetic permeability μ was performed on a sample that had been subjected to annealing at 500 ° C. for 60 seconds, which was a heat treatment equivalent to shrink fitting.

FIG. 3 is a diagram showing the relationship between the rolling reduction in temper rolling and the magnetic permeability. Here, instead of permeability, 0.3
Product μ × t of permeability μ and plate thickness t (mm) in Oe magnetic field
And the rolling reduction of the temper rolling. Up to a rolling reduction of 0.5% in temper rolling, the magnetic permeability of the material slightly decreases as the rolling reduction increases, but no significant change in the magnetic permeability is observed. On the other hand, when temper rolling at a rolling ratio exceeding 0.5% is performed, a remarkable decrease in magnetic permeability is observed.

Although the cause is not necessarily clear, according to the results of considerations by the present inventors, the rolling reduction of the temper rolling is 0.5%.
%, The strain introduced into the steel sheet by the temper rolling is relatively uniformly introduced into the extreme surface of the steel sheet, but is introduced only very coarsely inside the steel sheet. It is probable that the decline was not significant.

In this type of steel sheet, the temper rolling is performed for the purpose of preventing a surface defect generally called a stretcher strain mark after working and forming, but in the case of a heat shrink band, the band is formed. Forming and processing are not so severe from the beginning, so that no remarkable surface defects occur without temper rolling. Rather, from the viewpoint of obtaining a high magnetic permeability, when there is no problem in appearance, it is desirable to omit the temper rolling.

4. Relationship between Annealing Temperature and Magnetic Permeability C: 0.002%, Si: 0.03%, Mn: 1.2%,
P: 0.08%, S: 0.005%, sol. Al: 0.03%, N: 0.002%
Hereinafter, steel having a composition of Ti: 0.03% and B: 0.0005% is melted in a laboratory, hot-rolled to 2.8 mmt, then cold-rolled to 1.0 mmt, and annealed at 720 to 930 ° C for 90 seconds. After, at 450 ℃ 2
A heat treatment equivalent to shrink-fitting at 500 ° C. for 60 seconds was used without subjecting to overaging treatment for a minute and temper rolling.

FIG. 4 is a graph showing the relationship between the annealing temperature and the product μ × t of the magnetic permeability μ and the plate thickness t (mm) in a magnetic field of 0.3 Oe.

When the annealing temperature is up to 780 ° C., the magnetic permeability of the material is slightly improved with the increase of the annealing temperature, but no remarkable change in the magnetic permeability is recognized. On the other hand, when annealing is performed in a temperature range of 800 ° C. to 900 ° C., the magnetic permeability is significantly improved. Further, when the annealing temperature is increased to 930 ° C., the magnetic permeability decreases.

This change in the magnetic permeability corresponds to the microstructure of the steel sheet. When the annealing temperature is lower than 800 ° C., a remarkable improvement in the magnetic permeability is recognized due to insufficient recrystallization and subsequent grain growth. When the annealing temperature is 800 ° C or higher and 900 ° C or lower, the magnetic permeability increases with recrystallization and grain growth,
It is considered that when the annealing temperature exceeds 900 ° C., transformation occurs, so that the crystal grains are refined and the magnetic permeability is reduced again.

Therefore, the annealing temperature should be between 800 ° C. and 900 ° C.
The temperature must be below 840 ° C. and preferably 900 ° C. or below. In consideration of material stability in a high temperature range, the annealing temperature is more preferably 840 ° C or more and 875 ° C or less.

5. Overaging conditions and magnetic properties and their changes over time Samples: C: 0.002%, Si: 0.01% or less, Mn: 1.0
%, P: 0.07%, S: 0.006%, sol. Al: 0.04%, N: 0.0
A steel having a composition of not more than 02%, Ti: 0.03%, and B: 0.0008% was hot-rolled to 3.2 mmt after melting in a laboratory. afterwards,
Cold rolled to 1.2mmt, after annealing at 850 ° C for 90 seconds, 170 ° C ~
An overaging treatment was performed at 550 ° C. for 2 minutes, and a heat treatment at 500 ° C. for 60 seconds equivalent to shrink fitting was performed without temper rolling. Further, in order to investigate the change with time, a sample subjected to a heat treatment (acceleration test) at 150 ° C. for 100 hours after a heat treatment equivalent to shrink fitting was also used.

FIG. 5 is a diagram showing the overaging conditions, the magnetic characteristics, and the changes over time. As is clear from this figure,
The effect of the overaging temperature on the product μ × t of the magnetic permeability μ and the plate thickness t (mm) in a 0.3 Oe magnetic field after an acceleration test at 150 ° C. for 100 hours is relatively minor. This is an effect in accordance with the limitation of the additive component elements and their contents described above. However, among these, when the overaging treatment is performed at a temperature of 250 ° C. or more and 500 ° C. or less, it can be seen that the material has excellent magnetic permeability.

As described above, by performing the overaging treatment at a temperature of 250 ° C. or more and 500 ° C. or less, the μ × which is superior after the accelerated test is superior to the case where the overaging treatment is performed in other temperature ranges.
You can get t. Although the cause is not clear, it is considered to be related to the dissolution and precipitation behavior of carbides in the steel.

That is, when carbides and the like are partially dissolved during annealing to form solid solution C, if the overaging temperature is less than 250 ° C., the solid solution C in the steel does not sufficiently precipitate even after the shrink-fitting treatment. ,
Although the magnetic permeability immediately after the shrink fitting is high, carbides are finely precipitated after the shrink fitting, resulting in a decrease in the magnetic permeability.

On the other hand, when the overaging temperature exceeds 500 ° C., the amount of the residual solid solution C increases, and the carbide cannot be sufficiently precipitated even by the subsequent shrink-fitting treatment. It is presumed that a decrease in magnetic permeability is observed after the accelerated test due to precipitation of.

[0055]

EXAMPLES The test steels shown in Table 1 were melted, heated to 1200 ° C. to 1280 ° C., and hot-rolled to a thickness of 3.2 mmt at a finishing temperature of 900 ° C. and a winding temperature of 680 ° C. After pickling the obtained hot rolled sheet, the sheet thickness is 0.8mmt ~
After cold rolling to 1.6 mmt, it was annealed at 750 ° C. to 950 ° C. for 90 seconds, and then overaged at 210 ° C. to 550 ° C. for 2 minutes.

[0056]

[Table 1]

These steel sheets are further provided with a shrink fit of 50%.
After heating at 0 ° C. for 5 seconds and air cooling to room temperature, the yield stress, DC magnetic properties (permeability at 0.3 Oe, and coercive force when excited to an external magnetic field of 10 Oe) were measured for a ring test piece (outer diameter 45 mm). , Internal diameter 33 mm).

Further, as an evaluation of magnetic stability, a DC magnetic property of a material subjected to a heat treatment at 150 ° C. for 100 hours after a heat treatment equivalent to shrink fitting was also evaluated. 850 ° C
Process the annealed material into a band of a predetermined shape, heat it to 500 ° C,
It was fitted into a 9-inch TV cathode ray panel and evaluated for geomagnetic drift. Table 2 shows the results. As for the geomagnetic drift properties, test steel F
And the relative value when the geomagnetic drift amount of the 1% temper-rolled material is set to 1.

[0059]

[Table 2]

As shown in Table 2, in the examples of the present invention in which the test steel components, the annealing temperature, and the temper rolling ratio were within the range of the present invention, the magnetic permeability μ and the sheet thickness t (mm) in a 0.3 Oe magnetic field were used. ) Is 350 or more, and it has been confirmed that the product exhibits excellent characteristics of geomagnetic drift. Further, it was confirmed that when the overaging treatment temperature was in the range of 250 ° C. or more and 500 ° C. or less, more stable magnetic properties were exhibited. On the other hand, in the comparative examples out of the range of the present invention, μ × t is out of the appropriate value, and a complicated process is required as a countermeasure for color misregistration.

The yield strength of the examples of the present invention in which the test steel composition, annealing temperature, temper rolling reduction, etc. are within the range of the present invention is mostly around 25 kgf / mm ² , and all others are 23 to 28 kgf / mm ^{2. 2,} which is a level that does not affect the explosion-proof property.

[0062]

According to the present invention, by reducing the amount of Si and adding Ti + B, a high magnetic permeability is ensured in spite of low Si, and a reduction in color misregistration is focused on the product of the magnetic permeability and the plate thickness. I'm trying. As a result, according to the present invention, a steel sheet suitable for a heat shrink band having a high magnetic permeability and a small geomagnetic drift can be obtained. By using the steel sheet according to the present invention for a heat shrink band of a cathode ray tube, a sufficient magnetic shielding property is secured and the problem of color misregistration is solved.

[Brief description of the drawings]

FIG. 1 is a diagram showing the relationship between the amount of Si and the amount of geomagnetic drift.

FIG. 2 is a diagram showing a relationship between μ × t and a geomagnetic drift amount.

FIG. 3 is a diagram showing a relationship between a temper reduction ratio and μ × t.

FIG. 4 is a diagram showing a relationship between an annealing temperature and μ × t.

FIG. 5 is a graph showing the relationship between the overaging temperature and μ × t.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Katsumi Nakajima, 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Kenji Tahara 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan (72) Inventor Yasuyuki Takada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Nihon Kokan Co., Ltd. (72) Inventor Nobuo Yamagami 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan Inside the corporation

Claims (4)

[Claims] 1. C: 0.005% by weight as a chemical component
Below, Si: 0.1% or less, Mn: 0.1% or more and 2% or less, P: 0.15
%, S: 0.02% or less, sol. Al: 0.08% or less, N: 0.0
Contains 0.05% or less, Ti: 0.02% or more and 0.06% or less, B: 0.0003% or more and 0.005% or less, and 0.3 Oe after shrink fitting
A product for heat shrink bands, wherein the product of the magnetic permeability and the plate thickness (mm) in a magnetic field of not less than 350. 2. The heat shrink band steel sheet according to claim 1, wherein the product of the magnetic permeability and the sheet thickness (mm) in a 0.3 Oe magnetic field after the shrink fitting is 400 or more. 3. The steel having the chemical composition according to claim 1 is hot-rolled, subsequently cold-rolled, and then the obtained steel sheet is annealed in a temperature range of 800 ° C. or more and 900 ° C. or less, or And a temper rolling at a rolling reduction of 0.5% or less after the annealing. 4. The steel sheet for a heat shrink band according to claim 3, wherein the overaging treatment is performed in a temperature range of 250 ° C. or more and 500 ° C. or less after annealing or between annealing and temper rolling. Manufacturing method.