JPH0790393A - Convector plate for preventing temper color - Google Patents

Abstract

PURPOSE:To easily prevent the generation of a temper color and to hold the preventing effect in repeated use by constituting a convector plate used to a batch annealing of a cold-rolled coil with a stainless steel sheet cladded on the surface contacting with the coil edge. CONSTITUTION:This convector plate is composed of a plate body 2 made of the conventional tool steel, and an abverse surface stainless steel sheet 3 and a reuarse surface stainless steel sheet 4 joined mutually. The plate body 2 is an annular disk and is constituted so that this outer diameter is larger than the outer diameter of the cold-rolled coil and the inner diameter is smaller than the inner diameter of the cold-rolled coil. At the time of piling the cold- rolled coils on the base of a batch annealing furnace, firstly the convector plate having no steel sheet 4 is laid and the cold-rolled coil is loaded in the axial center direction. Successively, while interposing the convector plate having the steel sheets 3, 4, the cold-rolled coils are piled in the axial center direction and the convector plate having no steel sheet 3 is laid on the uppermost cold- rolled coil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a convector plate used for preventing temper color at a coil edge portion in batch annealing of cold rolled coils.

[0002]

2. Description of the Related Art In batch annealing of cold-rolled coils, as shown in FIG. 3, cold-rolled coils 23 are axially stacked on a base 22 of a batch annealing furnace 21 via a convector plate 24, and then stacked. The inner cover 25 is covered with the inner cover 25 to shut off the outside air, the inner cover 25 is replaced with a non-oxidizing atmosphere gas, and then the furnace body (bell) 26 is covered, and then the cold rolled coil 23 is non-oxidized until it reaches a constant temperature. Heated in a neutral atmosphere gas. The convector plate 24 interposed between the cold-rolled coils 23 has an opening at the center to allow the non-oxidizing atmospheric gas to pass therethrough, and is heated by the non-oxidizing atmospheric gas passing through the opening so that the coil Heat transfer from the edge side is promoted. Convector plate 2
As the material of No. 4, a hard steel material such as tool steel capable of withstanding the load of the cold rolled coil is selected.

In batch annealing of the cold rolled coil,
It is known that oxidative coloring called temper color occurs at the coil edge portion. This temper color is apt to occur in high carbon steel such as high carbon steel having a large amount of Si and Mn in steel, and when the temper color occurs, not only the quality of appearance is deteriorated, but also a chemical treatment of the cold rolled coil is performed due to a colored film. It also causes a decrease in sex. When the cold rolled coil is annealed at a high temperature, a split type convector plate is usually used to prevent thermal distortion of the convector plate. When the cold-rolled coils are stacked in the axial direction through this split type convector plate, as shown in FIG. 4, the edge 27 of the cold-rolled coil 23 does not come into contact with the portion 27a in contact with the convector plate 24. The portion 27b is formed. During the annealing, the water discharged from the steel sheet and the high-temperature non-oxidizing atmosphere gas pass through the portion 27b which is not in contact with the convector plate 24, so that the convector plate 24
The oxidation of the edge 27b that is not in contact with the edge is accelerated, and the temper color is generated.

Conventionally, as a method for preventing temper color in batch annealing of cold rolled coils, a method in which a wool-like soft spacer made of stainless steel fine wires is interposed as a cushion between the coil edge and the convector plate (Japanese Patent Laid-Open No. 53-53). No. 123319), a method of filling a ceramic fiber spacer in the outer peripheral portion and the inner peripheral portion between the coil edge and the convector plate (JP-A-57-76132), and the edge portion of the cold-rolled coil in advance. A method of covering with a thin steel plate or the like (Japanese Patent Laid-Open No. 60-128222), or a method of laminating a mild steel plate on the surface of the convector plate body in contact with the coil edge (Japanese Patent Laid-Open No. 4-3715).
Many proposals have been made.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the method disclosed in Japanese Patent No. 3319, not only is it troublesome to construct a wool-like soft spacer made of stainless steel thin wire between the coil edge and the convector plate,
It is necessary to remove this after annealing, and workability in the annealing operation is significantly deteriorated. Moreover, since stainless wool is very expensive and cannot be used repeatedly, it increases the annealing cost. Similarly, the method disclosed in JP-A-60-128222 requires time and cost to cover the edge portion of the cold rolled coil with a thin steel plate or the like, and is not satisfactory from the viewpoint of workability and economy. Absent. Further, the method disclosed in Japanese Patent Application Laid-Open No. 57-76132 has relatively improved workability and economical efficiency, but ceramic fiber spacers are interposed between the cold rolled coil and the convector plate at the outer and inner portions. So let's
Compared with the case where only the convector plate is used, the number of man-hours is increased considerably. Moreover, since the spacer made of ceramic fiber causes fatigue when repeatedly used and the effect of preventing temper color is deteriorated, it cannot be repeatedly used many times, and workability and economical efficiency are not satisfactory. Furthermore, JP-A-4-3715
The convector plate disclosed in Japanese Patent No. 31 is a soft steel plate made of S.
C content of low carbon cold rolled steel strips of PCC class is 0.3%
Although the following steels are used, when this convector plate is used, when the high temperature annealing of 700 ° C. or higher is repeated, the deformation of the mild steel plate becomes large due to thermal strain, and it becomes necessary to replace the mild steel plate within one month. Further, when the coil and the mild steel sheet were annealed at a high temperature, there was a problem that the coil and the mild steel sheet could not be separated due to the adhesion due to seizure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a temper color preventing convector plate which can prevent temper color easily and whose temper color preventing effect does not deteriorate even after repeated use.

[0007]

Means for Solving the Problems As a result of various tests and examinations for achieving the above-mentioned object, the inventors of the present invention have found that a high-temperature stainless steel plate is superposed on the surface of the convector plate body in contact with the coil edge. It was confirmed that the thermal strain due to repeated annealing was suppressed, that it could be used for a long period of time, and that the trouble of being unable to separate from the coil due to seizure could be eliminated, and reached the present invention.

That is, the present invention relates to a temper color preventing convector plate which is interposed between a plurality of cold rolled coils stacked in the axial direction of the base of a batch annealing furnace.
A convector plate for preventing temper color, wherein the convector plate comprises a plate body and a stainless steel plate laminated on at least a surface of the plate body in contact with the coil edge.

[0009]

In the convector plate of the present invention, the stainless steel plate is superposed on at least the surface of the plate main body that is in contact with the coil edge. Since there is no space exposed to the atmosphere, the occurrence of temper color at the coil edge is prevented. The improvement itself in the sealing property with the coil edge by the stainless steel plate is not so remarkable as compared with the mild steel plate, and cannot be explained as a cause for preventing the occurrence of temper color. This is because the generation of temper color depends on the flow rate of the atmospheric gas, and when the coil edge directly contacts the atmospheric gas,
Moisture supplied from the atmospheric gas is an integral of the flow velocity and time. However, if the ambient gas does not directly contact the coil edge, the flow velocity is equal to zero, and the moisture supplied from the atmospheric gas is equal to none. It is considered that the occurrence of

In the present invention, the stainless steel plate to be laminated on the plate body is, for example, SUS303,
A material such as SUS405 or SUS430 that has a small thermal strain and that does not cause a trouble such as separation that the coil edge and the stainless steel plate are seized and adhered to each other even during high temperature annealing does not occur. The thickness of the stainless steel plate is 1-5m
If it is less than 1 mm, the surface deformation of the stainless steel plate is large, the sealing property to the space between the adjacent edge portions in the cold rolled coil is insufficient, the temper color preventing effect is insufficient, and if it exceeds 5 mm. Not only does the convector plate become excessively heavy and the handleability deteriorates, but in some cases, the stacking height of the cold-rolled coils increases, which may limit the number of stacked coils.

[0011]

【Example】

Embodiment 1 Details of the present invention will be described below with reference to FIGS. 1 and 2 showing an embodiment. FIG. 1 is a vertical sectional view of a temper vector preventing convector plate of the present invention, and FIG. 2 is a development view of an upper stainless steel plate to be superposed on a plate body. 1 and 2, reference numeral 1 denotes a temper vector preventing convector plate of the present invention, which is a plate body 2 made of existing tool steel, an upper surface stainless steel plate 3 joined to the upper surface of the plate body 2, and a plate body 2 The lower surface of the stainless steel plate 4 is joined to the lower surface of the. The plate body 2 is an annular disk, the outer diameter of which is larger than the outer diameter of the cold rolled coil and the inner diameter of which is smaller than the inner diameter of the cold rolled coil.

The upper surface stainless steel plate 3 to be joined to the upper surface of the plate body 2 is, as shown in FIG.
An annular body portion 5 having the same planar shape as that of
It is composed of four projecting pieces 6 projecting outward from four locations on the outer peripheral edge in the circumferential direction. The four projecting pieces 6 are bent downward and welded to the lower surface stainless steel plate 4 joined to the lower surface of the plate body 2. The lower surface stainless steel plate 4 joined to the lower surface of the plate body 2 is an annular body having the same planar shape as the plate body 2. It should be noted that the upper surface stainless steel plate 4 joined to the upper surface of the plate body 2 by projecting four projecting pieces outward from four locations in the circumferential direction on the lower surface stainless steel sheet 4 and bending the four projecting pieces upward If the upper surface stainless steel plate 3 is welded to the plate body 3, the upper surface stainless steel plate 3 can be formed into an annular body having the same planar shape as the plate body 2 having no protruding piece 6.

Since the upper surface stainless steel plate 3 of the temper color preventing convector plate 1 at the upper end and the lower surface stainless steel plate 4 of the temper color preventing convector plate 1 at the lower end do not contact the edge portion of the cold rolled coil, they are omitted. be able to. Further, the upper surface stainless steel plate 3 and the lower surface stainless steel plate 4 may not be joined to the plate body 2, but may be interposed between the coil edge and the plate body 2 when stacking the cold rolled coils. Further, the outer diameter and the inner diameter of the upper surface stainless steel plate 3 and the lower surface stainless steel plate 4 must be appropriately selected within the range of the outer diameter of the cold rolled coil and the inner diameter of the cold rolled coil to match the outer diameter and the inner diameter of the plate body 2. There is no.

With the above configuration, when cold-rolled coils are stacked on the base of the batch annealing furnace,
The temper color preventing convector plate 1 having no lower surface stainless steel plate 4 is placed on the base to stack the cold rolled coils in the axial direction, and then the upper surface stainless steel plate 3 and the lower surface stainless steel plate 4 are arranged on the upper and lower surfaces of the plate body 2. A temper color prevention convector plate 1 in which the cold rolled coils are sequentially stacked in the axial direction with the temper color prevention convector plate 1 having the And complete the stacking of cold rolled coils. In this case, the work of interposing the temper color preventing convector plate 1 on the edge portion of the cold-rolled coil can be performed in the same manner as the work of interposing only the conventional plate body 2.

As a result, the edge portion of the cold rolled coil is brought into close contact with the upper surface stainless steel plate 3 and the lower surface stainless steel plate 4 joined to the upper and lower surfaces of the plate body 2 of the temper color preventing convector plate 1, and the edge of the cold rolled coil is formed. Direct contact with the atmospheric gas in the part is prevented, and the occurrence of temper color can be prevented. Further, the temper color preventing convector plate 1 of the present invention is configured such that the upper surface and the lower surface of the plate body 2 are joined with the upper surface stainless steel plate 3 and the lower surface stainless steel plate 4 having a small thermal strain.
Deformation due to thermal strain due to repeated high temperature annealing can be prevented,
It can be used for a long period of time, and the cold-rolled coil and the upper surface stainless steel plate 3 and the lower surface stainless steel plate 4 can be used.
Inseparability due to close contact with can be eliminated.

Example 2 C: 0.57%, Si: 0.27%, Mn: 0.80%
Cold-rolled coil containing (plate thickness 1.0 mm, plate width 1010
mm, an inner diameter of 610 mm, and an outer diameter of 1680 mm) were used for stacking four stages on a base of a batch annealing furnace and annealing, and the temper vector preventing convector plate of the present invention described in Example 1 was used. As a convector plate for temper color prevention, inner diameter 400 mm, outer diameter 1900 m
A plate main body made of tool steel having a thickness of 70 mm and a thickness of 70 mm was joined to an upper surface stainless steel plate and a lower surface stainless steel plate made of a SUS303 stainless steel plate having a thickness of 5.0 mm. After stacking the cold-rolled coils, cover the inner cover to block the outside air, replace the inner cover with hydrogen gas, cover the furnace body (bell), ignite the burner and anneal at 720 ° C. for 20 hours. The annealing test of cooling to 150 ° C. in a% hydrogen gas atmosphere was repeatedly performed. As the atmosphere gas, 100% hydrogen gas with a dew point of −50 ° C. was used. For comparison, in batch annealing under the same conditions, when only the plate body was used as the convector plate, and when a ceramic fiber spacer was interposed between the coil edge part and the convector plate consisting only of the plate body. The annealing test was repeated.

The distance from the coil edge of the colored portion was measured for each of the four cold-rolled coils which had been subjected to batch annealing, and when the temper color preventing convector plate of the present invention was used, all were 25 mm or less. Even after repeated use 200 times, the temper color preventing effect did not deteriorate. On the other hand, when only the plate body was used as the convector plate, the distance from the coil edge of the colored portion was 80 to 100 mm.
Further, when a ceramic fiber spacer is interposed between the coil edge portion and the convector plate consisting of only the plate body, the temper color prevention effect is similar to the temper color prevention convector plate of the present invention at the beginning of use. However, so-called fatigue occurs in the ceramic fiber spacer during repeated use,
The effect of preventing temper color was significantly reduced.

[0018]

[Example 3] A plate having the composition shown in Table 1 having a thickness of 2.0 mm, a width of 1150 mm, an inner diameter of 610 mm, and an outer diameter of 1700 to 180.
When a cold rolled coil of 0 mm and a single weight of 16.0 to 17.0 Ton was stacked and annealed on the base of a batch annealing furnace in three stages, the temper color preventing convector plate of the present invention described in Example 1 was used. did. As a temper vector preventing convector plate, an upper surface stainless steel plate and a lower surface stainless steel plate made of a SUS303 stainless steel plate having a thickness of 5.0 mm are joined to a plate body made of a tool steel having an inner diameter of 600 mm, an outer diameter of 2000 mm and a thickness of 90 mm. I used the one. After stacking the cold-rolled coils, cover the inner cover to block the outside air, replace the inner cover with hydrogen gas, cover the furnace body (bell), ignite the burner and anneal at 720 ° C. for 20 hours. The annealing test of cooling to 150 ° C. in a% hydrogen gas atmosphere was repeatedly performed. Atmosphere gas has a dew point of -50 ° C.
00% hydrogen gas was used. For comparison, in batch annealing under the same conditions, inner diameter 600 mm, outer diameter 2000
mm, a plate body made of 90 mm thick tool steel,
An annealing test was conducted on the case where the convector plate of Conventional Example 1 in which the upper mild steel plate and the lower mild steel plate made of 5.0 mm thick mild steel plates were joined and the convector plate of Conventional Example 2 consisting only of the plate body were interposed. It was carried out repeatedly.

The distance from the coil edge of the colored portion was measured for each cold rolled coil that had been subjected to batch annealing. The results are shown in Table 2. In addition, the durability of each convector plate was investigated by the number of times annealing was possible. The results are shown in Table 2.

[0020]

[Table 1]

[0021]

[Table 2]

As shown in Table 2, when the temper color preventing convector plate of the present invention was used, the temper color generation width was 25 mm or less, and the temper color preventing effect was obtained even after repeated use 200 times. It never faded. The plate body of Conventional Example 1 has a thickness of 5.
When a convector plate in which an upper surface mild steel plate and a lower surface mild steel plate made of 0 mm mild steel plates were joined was used, the temper color generation width was 25 mm or less in both cases.
Deformation of the mild steel plate increased due to thermal strain after 10 to 15 times of annealing, and it was necessary to replace the mild steel plate within about one month. Further, seizure between the coil and the mild steel plate resulted in poor separation. In addition, when the convector plate consisting only of the plate body of Conventional Example 2 is used, it is repeated 20 times.
Even if it was used 0 times, the temper color preventing effect did not deteriorate, but the temper color generation width was 80 to 100.
mm occurred.

[0023]

As described above, the temper color preventing convector plate of the present invention can prevent the temper color with the same labor as when using a normal convector plate, and the stainless steel plate to be superposed on the plate body is It is economical because the unit price is easy and the temper color prevention effect does not deteriorate even after repeated use.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a temper vector preventing convector plate of the present invention.

FIG. 2 is a development view of an upper stainless steel plate to be superposed on the plate body.

FIG. 3 is a vertical cross-sectional view showing a conventional batch annealing furnace for cold rolled coils.

FIG. 4 is a partially cutaway sectional view showing how the coil edge portion contacts the convector plate.

[Explanation of symbols]

 1 Temper color prevention convector plate 2 Plate body 3 Upper surface stainless steel plate 4 Lower surface stainless steel plate 5 Body part 6 Projection piece 21 Batch annealing furnace 22 Base 23 Cold rolled coil 24 Convector plate 25 Inner cover 26 Furnace body 27 Edge

Claims (1)

[Claims] 1. A temper color preventing convector plate interposed between a plurality of cold-rolled coils stacked axially on a base of a batch annealing furnace, wherein the convector plate is a plate body and at least a coil edge of the plate body. A temper vector color prevention convector plate, which is made of a stainless steel plate laminated on the surface that contacts with.