JPH03126848A - Annealing method - Google Patents

Abstract

PURPOSE:To carry out heat treatment free from the waste of heat and time even in the case of a high-temp. coil by chucking an Al-base metal sheet or bar at the inlet side of an annealing furnace at the time of applying continuous annealing to the above shut or bar. CONSTITUTION:For example, an annealing furnace 3 consisting of a heating zone 31 and a cooling zone 32 is disposed between an uncoiler 1 and a recoiler 2, and a chuck 4 is provided to the position between the inlet side and the outlet side of the furnace 3 into a state capable of performing a reciprocating motion through the inside of the furnace. For example, a chain 5 is provided along the course, the inlet side of the furnace the inside of the furnace the outlet side of the furnace the recoiler the inlet side of the furnace, to which a pulley 6 is provided to move the chuck 4. The end of an Al or Al-alloy coil W is gripped by means of the chuck 4, by which the coil W can be moved from the inlet side of the furnace through the inside of the furnace to the inlet side. The end of the coil W is gripped by means of the chuck 4, and this coil W is passed through the furnace and coiled round the recoiler 2. By this method, an accumulator in a continuous annealing furnace can be omitted, and the purpose can be accomplished.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an annealing method for aluminum or aluminum alloy sheets, and in particular, an annealing method suitable for continuously annealing hot rolled coils in a high temperature state. Regarding.

(Prior art and problems to be solved) Aluminum and aluminum alloy sheet strips (coils) are widely used as materials for beverage containers, utensils, and automobiles. It is manufactured through the process of → soaking → hot rolling → (annealing) → cold rolling (including annealing).

By the way, the annealing method used in the above process has conventionally been a batch annealing method and a continuous annealing method (CAL: heating annealing performed while uncoiling the coil).The former batch annealing method generally involves heating the coil as it is. Cooling rate 40℃/hr, 360
While it is carried out under the conditions of holding at °C for 2 hours,
The latter continuous annealing method has the advantage of excellent productivity because the coil is continuously annealed while being unwound. Regarding the latter continuous annealing method, various improvements have been proposed (for example, Japanese Patent Publication No. 61-7465, Japanese Patent Publication No. 62-37705, Japanese Patent Publication No. 62-6740, Japanese Patent Publication No. 62-13421, etc.).
.

On the other hand, for continuous annealing furnaces, there are two types: - a hot air type with a heating and cooling rate of about 1000℃/win in the shell, and a hot air type with a heating and cooling rate of about 1
There is an electromagnetic induction type with a temperature of 000°C/win, and its configuration was introduced at the 18th Japan Society of Light Metals Symposium, Type 65, etc., but in any case, as shown in Figure 3, This configuration requires an accumulator 11 to be disposed on the inlet side (and outlet side) of the furnace in order to connect the coils.This accumulator 11 consists of a large number of rolls 12, and the rolls have a A rubber roll with a temperature of about 150°C is used. Therefore, from the viewpoint of the heat resistance of the roll, it is necessary to pass the coil through the coil at a temperature of usually less than 100°C, preferably 50°C or less. In other words, conventional continuous annealing equipment The configuration is suitable for annealing cold coils.

Therefore, when a high temperature coil, for example a hot rolled coil at about 300°C, is to be continuously annealed without being allowed to cool after hot rolling, the coil temperature should be less than 100°C, preferably 50°C or less. Otherwise, the accumulator cannot be passed through the plate, so it must be left to cool or cooled, which wastes a lot of heat and time, and there is a problem that the advantages of the continuous annealing furnace, which has excellent productivity, cannot be effectively utilized. Furthermore, there was also the problem of making continuous annealing of the above-mentioned high-temperature coil difficult.

An object of the present invention is to eliminate the drawbacks of the prior art related to the continuous annealing method described above, and to provide an annealing method with excellent productivity that can heat-treat even high-temperature coils without wasting heat or time. It is.

(Means for Solving the Problems) In view of the above problems, the present inventors have developed an accumulator in a conventional continuous annealing system, ie.

As a result of intensive research aimed at improving accumulators with a large number of rolls, we first developed a method to improve the material and arrangement of the rolls in accumulators. However, although this method allows the sheet to be threaded at high temperatures, it has the drawback that the large number of rolls in the accumulator causes a large amount of cooling to occur during sheet passing through the accumulator, and that heat waste cannot be sufficiently reduced. Of course, since the method is basically the same as that of accumulating coils using rolls, the improvement is insufficient in terms of time wastage.

Therefore, the present inventors determined the relationship between the cooling temperature during sheet passing through the accumulator and the time required for one sheet to pass through the number of rolls, and
We have repeatedly considered ways to replace the accumulator.

As a result, ■The more rolls there are, the longer the time it takes for one sheet to pass.
Coils can be cooled easily; Accumulators are important for connecting coils, but even if there is no accumulator, you can grab the tip or side end of the coil and apply appropriate tension to the recoiler (take-up reel). It was discovered that it can be wrapped around. Based on this knowledge, as a result of further detailed research, we have now developed a new continuous annealing method that wastes less heat and time.

That is, the gist of the present invention is an annealing method characterized in that, when continuously annealing an aluminum or aluminum alloy plate, the plate is chucked at the entry side of the annealing furnace and charged as it is into the annealing furnace. It is something.

The present invention will be explained in more detail below.

(effect) First, an example of an annealing furnace used in the method of the present invention will be explained.

The one shown in Figure 1 is a continuous annealing furnace.
An annealing furnace 3 consisting of a heating zone (or preheating zone and holding zone) 31 and a cooling zone 32 is arranged between the uncoiler 1 and the coiler 2, but unlike the conventional accumulator consisting of a large number of rolls, Therefore, there is no connecting device. In other words, a chuck 4 is provided between the entrance and exit sides of the annealing furnace so that it can reciprocate (reverse) through the furnace, and the aluminum coil W is The chuck 4 grips the end portion (usually the side portion) and is configured to be able to move from the entrance side of the furnace through the furnace to the exit side.

Specifically, as illustrated in FIG. 2, the tip of the coil is gripped by a chuck 4, passed through a furnace, and wound around a recoiler.

The chuck 4 may be of a mechanical type or an electromagnetic type, and can be reciprocated (reverse) by an appropriate conveying means. For example, as shown in Figures 1 and 2, the chain 5
An example is a pulley system in which a pulley 6 is provided on the chuck 4 to move the chuck 4.

Note that the heating zone may be either a hot air type or an electromagnetic induction type, and the latter is preferable in terms of shortening the length of the heating zone.

Further, the cooling zone may be either an air-cooled type or a water-cooled type, and the latter is also preferable. However, in the latter case,
It is necessary to install a leveler on the exit side.

Since the present invention utilizes the above-described annealing method, it is particularly effective when continuous annealing is performed without cooling the coil after hot rolling, and waste of heat and time can be saved. Of course, this method can also be applied to continuous annealing of cold coils, which saves time.

Next, examples of the present invention will be shown.

(Example) Aluminum coil hot-rolled at 300"C (
3004, plate thickness 2.5 mm), was subjected to continuous annealing using a continuous annealing furnace having the configuration shown in FIGS. 1 and 2, and the temperature when one plate was annealed was determined.

In this case, the sheet passing speed was 50 m/win, and the distance to the heating zone was 1011 mm.

For comparison, continuous annealing was performed using a continuous annealing furnace having a conventional configuration as shown in FIG. 3, and the temperature at which the plate was annealed was determined. In this case, the accumulator threading speed is 50 m.
/min, and the distance to the heating zone was 150@.

The temperature change of the coil up to the heating zone is shown in Table 9. From the same table, according to the method of the present invention, the time required to reach the heating zone is short, and there is no contact cooling as there is no contact with the roll of the accumulator. Therefore, almost no temperature drop is observed.

On the other hand, in the conventional method, since an accumulator is used, it takes a long time to reach the heating zone, and the temperature is significantly lowered by contact with the rolls, resulting in a significant temperature drop.

Table 1 (Effects of the Invention) As detailed above, according to the present invention, the accumulator in conventional continuous annealing can be omitted. It is possible to eliminate waste in both cases, which greatly contributes to improving the productivity of aluminum coils.

[Brief explanation of the drawing]

1 and 2 are explanatory diagrams showing an example of the configuration of a continuous annealing furnace used in the method of the present invention.
The figure shows the chucking state of the coil, and FIG. 3 is an explanatory diagram showing the configuration of a conventional continuous annealing furnace. 1...Uncoiler-12...Recoiler 3...
Continuous annealing furnace, 3□...Heating zone, 3□...Cooling zone, 4
...Chuck, 5...Chain, 6...Pulley, 1
0...Welding machine, 11...Accumulator, 12.
...Roller, W...Aluminum coil.

Claims (3)

[Claims] (1) An annealing method characterized in that when continuously annealing an aluminum or aluminum alloy strip, the strip is chucked on the entry side of an annealing furnace and then charged into the annealing furnace as it is. (2) The method according to claim 1, wherein the chuck is movable back and forth between the entrance side of the annealing furnace, the inside of the furnace, and the exit side. (3) The method according to claim 1 or 2, wherein the aluminum or aluminum alloy strip to be charged into the annealing furnace is in a high temperature state.