JPS63220901A - Warm rolling equipment for strip coil - Google Patents

Abstract

PURPOSE:To improve yield and quality by rolling a strip rewound in temp. insulating state from a tension reel via deflector roll and rolling heated at optimum temp. and winding on one part of a heated and temp. insulating reel. CONSTITUTION:The strip S heated at 300-600 deg.C by a heating device 4a is fed by rewinding from one part of tension reel 2a. It is rolled by a rolling roll 7 via a deflector roll 3. In this case rolls 3, 7 are made so as to maintain the temp. at 200 deg.C by heating means 6a, 6b, 9. The strip S having completed rolling is wound by a tension reel 4b of the other part temp. insulated by a heat holding furnace 4b. The product having excellent magnetic characteristic can be manufactured with good efficiency by repeating the above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a warm rolling facility suitable for thin plate coils, particularly difficult-to-work thin plates.

[Conventional technology]

In recent years, there has been a strong demand for miniaturization and higher efficiency of electromagnetic and electronic components from the viewpoint of resource and energy conservation, and silicon steel sheets with excellent soft magnetic properties, especially iron loss, are required. The soft magnetic properties of silicon steel sheets improve with the addition amount of 81, especially when 6.5 is added.
It is known that since it exhibits the highest magnetic permeability near wt % and also has a high specific electrical resistance, iron loss is also reduced. This type of steel plate has a Sl content of 4. When the temperature exceeds Owt%, workability deteriorates rapidly, and for this reason, it was previously thought that it was impossible to manufacture high-silicon steel sheets on an industrial scale by the rolling method, but recent research shows that It has been found that thin plate rolling is possible.

[Problems that the invention attempts to solve]

However, with conventionally commonly used rolling equipment, it is difficult to ensure the bending deformation of the coil and the temperature of the material, making it difficult to roll high-silicon steel sheets into thin sheets. For this reason, for example, JP-A-61-135407 proposes equipment in which the area from the first return reel to the first stand of the rolling mill is covered with a heat-insulating wall, but even with such equipment, Cracks caused by bending with deflector rolls and cracks during rolling cannot be sufficiently prevented.

The present invention was made in view of these conventional problems, and aims to provide warm rolling equipment that can efficiently roll difficult-to-work thin sheets such as high-silicon steel sheets without causing cracks or the like. It is something to do.

[Means to solve the problem]

Therefore, the present invention provides rolling equipment that reverse-rolls a strip between tension reels, maintains the strip at a predetermined temperature at all times during rolling, and prevents cracking or breakage due to bending or processing. The configuration is as follows. That is, the rolling equipment includes a rolling mill, tension reels provided at the entrance and exit sides of the rolling mill, and deflector rolls provided between each of these tension reels and the rolling mill. The tension reel is placed in a heat retention furnace having heating means, and is also placed in a rolling roll of a rolling mill and the deflector roll.

Heating means are provided to heat the rolls.

Furthermore, at the inlet and outlet of the rolling mill.

S) A heating device for the IJ tube is provided.

[For production]

The strip is reverse rolled in a rolling mill between tension reels, and in the case of high-silicon steel sheets, a hot rolled coil, typically about 2 m thick, is rolled into a thin sheet of about 0.5 m thick. The rolling rolls of the rolling mill are preheated to about 200° C. (surface temperature) by heating means, and the deflector rolls are also constantly heated to about 200° C. (surface temperature) by heating means. The strip coil is heated and maintained at a temperature of about 300 to 600°C in a heat retention furnace, and the strip that is unwound from one tension reel and exits the heat retention furnace is rolled by a rolling roll via a deflector roll. Ru.

Since the deflector roll is heated, the temperature of the IJ tube passing through it is suppressed from decreasing, and bending and breakage at the deflector roll portion is prevented. After passing through the deflector roll, the IJ tube is heated by a heating device at the inlet of the rolling mill to maintain the strip temperature during rolling.

Caught in a rolling mill. Since the rolling rolls are preheated, heat loss from the strip at the rolling rolls is also minimized. The strip leaving the rolling roll is heated to a high temperature by a heating device provided on the exit side thereof, passes through a heated deflector roll, and is wound onto the other tension reel in a heat retention furnace.

Even in this heat retention furnace, the temperature of the strip coil is 200 to 600℃.
It is kept heated to a certain degree. Then, such rolling is repeated, and (i) the IJ tube is rolled into a thin plate.

Figure s2 shows the air cooling temperature drop according to the strip thickness ζ -3t
(Decrease from plate temperature 400℃ in atmosphere 25℃1ii
)'E- As shown, the temperature drop of the thin IJ tube is extremely large.

For this reason, if the strip is rolled without providing any heating means between the tension reels, a warm state cannot be maintained. Furthermore, Fig. 3 shows the temperature drop of the strip due to roll contact during rolling in terms of the relationship between the rolling roll surface temperature and the post-rolling temperature of the strip.By keeping the rolling roll surface temperature at a predetermined temperature, It can be seen that rolling can be carried out while effectively suppressing the temperature drop of the strip.

As mentioned above, the strip is always kept at a predetermined temperature or higher (for example, 200°C or higher) during reverse rolling, and the strip is bent at the tension reel section, deflector roll section, and rolling section.
Rolling is performed while properly preventing cracks and breaks due to processing.

In addition, in the case of rolling a high-silicon steel plate, (i) the IJ tube is heat-retained in a heat retention furnace between each pass of reverse rolling, thereby performing an inter-pass recovery treatment and improving its maximum magnetic permeability. In other words, the strain introduced into the structure during rolling is
It is moderately released by low-temperature heat treatment by heat retention in a heat retention furnace, and through repeated introduction of strain and moderate strain release, the texture of the final product changes, resulting in changes in the texture of the final product.

The magnetic properties are improved.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows an embodiment of the present invention, and the rolling equipment is
A rolling mill (1) and tension reels (2aX2b) provided on its entry and exit sides.

A deflector roll (3) is provided between each tension reel and the rolling mill.

Each of the tension reels (2a) and (2b) is arranged in a heat retention furnace (41) having a heating means. Each heat retention furnace (4) is configured as a gas furnace with a heating burner (5). Note that any suitable heating means can be used.

At the inlet and outlet of the rolling mill (1), heating devices (k) (6b) are provided for heating the strip to be passed. As for this heating device.

A gas furnace (for example, a C gas furnace), a heating furnace equipped with an electric radiant heater, a radiant tube, etc. can be used.

Two deflector rolls (3) are provided on the inlet and outlet sides of the rolling mill. Each deflector roll (3) is provided with heating means, and in this embodiment, each deflector roll (3) is configured to allow hot oil to flow therein.

Note that as other heating means, an appropriate configuration may be adopted, such as arranging a burner that can directly heat the roll surface nearby. Further, the number of deflector rolls influences the bending angle of the strip, and one or more deflector rolls are arranged depending on the roll diameter, arrangement state, etc.

The rolling roll (7) is equipped with a heating device for preheating the roll, and in this embodiment, heating burners (9) are provided so as to face the upper and lower rolling rolls (7). As the heating means, a high-temperature oil supply nozzle device may be provided opposite the backup roll (8), so that the rolling roll (7) can be preheated via the backup roll.

In other layers, (1G is a thickness gauge, α1) is a Fi thermometer, and (1z is a lubricating grease supply device).

As the rolling mill (1), any suitable type can be used, such as a 4-fold rolling mill as in this embodiment, a 6-fold rolling mill, a 5-fold rolling mill, a planetary rolling mill, etc. However, the present invention is not limited to this, but it can also be a reverse rolling mill with multiple stands. In the case of multiple stands, strip heating devices are provided at the inlet and outlet of each rolling mill. By using a rolling mill with multiple stands in this manner, rolling can be performed efficiently.

According to the rolling equipment described above, both heat retention furnaces (4a) (
The strip coil (A) in 4b) is usually 200 to 60
It is kept at a temperature of 0℃, and each deflector roll (3
) is also constantly heated by the heating means so that its surface temperature is about 200°C. Also, rolling roll (7)
is preheated or constantly heated by the heating means so that its surface temperature is about 200°C.

200~ unwound from one tension reel (2)
The sl-IJ tube (S) at about 600°C is bent by the deflector roll (3) and sent to the rolling roll (7), but since the deflector roll (3) is heated to about 200°C, the strip (S) can be kept at at least that level of temperature and can be passed through without breaking. The strip (S) is immediately introduced into the heating device (6a), heated to rolling temperature, and then rolled by the rolling mill (1).

Since the rolling roll is heated or preheated, heat loss from the strip (S) is also prevented here (see Figure 3).
Note that the rolling roll (force) does not necessarily need to be heated all the time; for example, it is necessary to preheat it first to prevent the strip temperature from decreasing in the initial stage until the strip becomes sufficiently humid, and then It is possible to maintain a predetermined surface temperature by heat transfer from the surface.

The rolled strip (S) is immediately introduced into the heating device (6b) on the exit side and heated, and then heated for 20 minutes in the same manner as above.
Deflector roll heated in summer (3
)8, the sheet is wound onto the other tension reel (2b) in the heat retention furnace (4b). The strip (S) is reverse rolled between the tension reels (21L) and (2b) as described above to form a thin plate of a predetermined thickness.

When reverse rolling a high-silicon steel plate as described above, the strip (S) is kept in the heat retention furnace (4a) (4b) for a predetermined period of time (usually about 1 to 10 minutes) between each pass to recover between passes. Treatment (300-600℃ low temperature heat treatment)
Through this inter-pass recovery treatment, the strain introduced into the structure during rolling is moderately released, and by repeating the introduction of strain by rolling and the moderate release of strain by recovery treatment,
The texture of the final product is improved in a way that is advantageous in terms of magnetic properties.

During rolling as described above, heat-resistant lubricating grease (e.g., grease with a flash point of 300°C or higher) is supplied to each rolling roll from the lubricating grease supply device α2. Also, high-temperature oil is used as a heating means for the rolling rolls. When a supply device is provided, hot oil of 200° C. or higher is usually applied from the supply device to the backup roll (8), and the rolling roll (7) is preheated through preheating of the backup roll.

〔Effect of the invention〕

According to the apparatus of the present invention described above, at least S) I
Since reverse rolling can be carried out while keeping the plate temperature always above 200°C when bending or rolling is applied to the J-tube, for example, St: 4. It becomes possible to roll even a difficult-to-work steel plate of Owt or more without causing any cracks or breaks.

Further, in the case of rolling a high-silicon steel plate, the sl-IJ tube is subjected to inter-pass recovery treatment by heat retention between each pass of reverse rolling, thereby improving the magnetic properties of the final product.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing one embodiment of the present invention. Figure 2 shows the amount of air cooling temperature drop depending on the IJ tube thickness. FIG. 3 shows the temperature drop of the strip due to contact with the rolls during rolling, as a relationship between the rolling roll surface temperature and the temperature of the strip after rolling.

Claims (1)

[Claims] A rolling mill and installed on the entry and exit sides of the rolling mill. The tension reel and each tension reel that can be Deflation installed between the rolling reel and the rolling mill A rolling equipment equipped with Kutarol, The tension reel has heating means. Placed in a heat retention furnace, the rolling rolls and the Add these rolls to the deflector roll. A heating means is attached to heat the rolling process. Strip heating equipment is installed at the inlet and outlet of the machine. Warm pressure for strip coils with a Extension equipment.