JPH07258747A - Continuous heat treatment method for non-ferrous metal strip - Google Patents

Abstract

PURPOSE:To restrain the generation of camber of the non-ferrous metal strip developed by the release of residual stress by carrying the non-ferrous metal strip in a waving state within the temp. zone of the residual stress release on the charging side of a furnace, at the time of floating up and carrying the non-ferrous metal strip in the furnace. CONSTITUTION:The non-ferrous metal strip S in carried in the floating-up state in a heat treatment furnace composed of a heating zone A, slow cooling zone B and cooling zone C to execute the continuous heat treatment. At this time, the temp. zone of the residual stress release at the charging side 1a is made to be a waving zone Zw for floating up and carrying the strip S in the waving state and the other is made to be a catenary zone Zc. In the waving zone Zw, floater nozzles composed of a pair of upper and lower pressure pads 11 and chevron pads 12 are arranged at prescribed intervals. The upper and lower pads 11, 12 are arranged so as to replace their positions vertically and alternately with each other and the floater nozzle 10 arranged with the chevron pad 12 at the upper part can vertically be shifted. By this method, the increase of the camber developed by the release of the residual stress is prevented and also, the camber developed at the time of rolling can be corrected.

Description

Detailed Description of the Invention

[0001]

The present invention relates to aluminum, aluminum alloys,
The present invention relates to a continuous heat treatment method for non-ferrous metal strips such that copper, copper alloys, and other non-ferrous metal strips are continuously heat-treated while being floated and transported.

[0002]

2. Description of the Related Art Generally, when heat-treating a non-ferrous metal strip while continuously transporting it from a heating zone to a cooling zone, the non-ferrous metal strip is easily scratched, so that the non-ferrous metal strip is not transported by contact with a roll or the like, and is removed from a nozzle box. The method of floating and supporting by the jetted gas is adopted. As is well known, this nozzle box is provided with slit nozzles extending in the width direction of the non-ferrous metal strip at predetermined intervals and facing each other inwardly on the surface facing the non-ferrous metal strip. The strips are arranged so as to face each other vertically so that the nozzle surface has a constant distance from the reference pass line.

By the way, in a non-ferrous metal strip, a so-called C twist or reverse C twist is generated in the rolling process in which the widthwise central portion of the strip projects upward or downward. Therefore, the distance between the nozzle surface and the reference path line of the non-ferrous metal strip depends on the warp amount of the non-ferrous metal strip generated by the rolling process, the swing amount due to the vibration of the non-ferrous metal strip that occurs during transportation, and the non-ferrous metal strip due to the vibration. It was determined by adding the amount of clearance formed between the non-ferrous metal strip and the nozzle surface when the strip was closest to the nozzle surface. The nozzle surface should be as close as possible to the non-ferrous metal strip surface in order to stably support the non-ferrous metal strip and to uniformly heat and cool the non-ferrous metal strip with the gas ejected from the nozzle box. Is preferred.

[0004]

As described above, the nozzle surfaces of the nozzle box are vertically opposed to each other while maintaining a certain distance from the reference path line. Occasionally, there was a situation in which the nozzle box was contacted and damaged. Therefore, conventionally, there has been a problem that the amount of the skimmer is increased to cope with the problem, and stable support, uniform heating, and cooling of the nonferrous metal strip cannot be sufficiently performed.

The present inventors believe that the above-mentioned cause may be due to the change of the initial warp amount during the heat treatment, and as a result of various studies, a non-ferrous metal strip having a predetermined warp amount was obtained in the rolling process. When charged into a continuous heat treatment furnace,
Charge zone of heating zone (for example, material temperature 350 ° C or less)
By heating at, the work hardening that occurs during rolling is eliminated, and as a result, the residual stress of the non-ferrous metal strip is released and warpage occurs, which is added to the warpage generated during the rolling process, increasing the overall warpage amount. It was discovered that it was to do. The amount of warpage due to the residual stress release is
It was also found that even the same non-ferrous metal strip varies depending on its rolling history. Further, in general, the C-zor and the reverse C-zor can waving a non-ferrous metal strip before the residual stress is released, and can be corrected by waving, but the residual stress is released. However, after the warp amount of about 10 mm or more, it becomes difficult to waving, and it is difficult to correct the generated warp.

[0006]

The present invention has been made based on the above findings, and in a method for continuously heat treating a non-ferrous metal strip while floating and transporting the non-ferrous metal strip in the furnace, the non-ferrous metal on the charging side of the furnace. In the residual stress releasing temperature range of the strip, the non-ferrous metal strip is conveyed in a waving state.

[0007]

According to the present invention, since the non-ferrous metal strip is levitated and conveyed in the waving state in the residual stress release temperature region on the furnace loading side, warpage due to residual stress release is suppressed. At the same time, the warpage that occurs during rolling is also corrected.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a continuous heat treatment furnace 1 for non-ferrous metal strips, for example aluminum strips S. The heat treatment furnace 1 is composed of a heating zone A, a slow cooling zone B, and a cooling zone C. An aluminum strip S to be treated is charged from the charging side 1a of the heating zone A, and a residual stress release temperature range (for example, material A temperature of 350 ° C. or less) is a waving zone Z _W for floating and transporting the strip in a waving state, and the other is a catenary zone Z _C for floating and transporting the strip in a catenary state.

In the waving zone Z _W ,
A floater nozzle 10 composed of a pair of upper and lower pressure pads 11 and 12 is arranged at a predetermined interval, and the pressure pad 11 has a slit nozzle for ejecting gas so as to face inward in the width direction of the aluminum strip. Is used, and as the pressure pad 12, a chevron pad having an excellent strip floating property is used. Hereinafter, the pressure pad 12 will be referred to as a chevron pad 12. And the waving zone Z _W
Then, as shown in FIG. 2, the floater nozzles 10 are arranged at predetermined intervals by alternating the vertical relationship of the pressure pad 11 and the chevron pad 12, and the floater nozzle 1 having the chevron pad 12 arranged on the upper part thereof.
0 is movable up and down.

As shown in FIGS. 3 to 6, the chevron pad 12 has a widthwise direction of the aluminum strip on the facing surface 20 (hereinafter referred to as "pad face 20") of the aluminum strip S conveyed in the arrow X direction. It has slit nozzles 21 and 21 extending in the Y direction) and a plurality of rectifying members 22 are provided between these slit nozzles 21 and 21. The straightening member 22 is formed in a V shape and is arranged in parallel with each other.
Each of the straightening vanes 23, 24 is provided with straightening vanes 25, 26 at opposite edge portions thereof, and a plurality of long holes 27, 28 extending in the strip width direction are formed, respectively.

A plurality of the straightening members 22 are symmetrically arranged so that the middle portions (bending portions) 29, 30 of the straightening plates project toward the ends, and the bolts 31, 32 are provided in the elongated holes 27, 28, respectively. And is fixed to the pad face 20 by inserting them respectively. Further, on the pad face 20, round nozzles 33, which are air ejection holes, are provided between the inner straightening plate 23 and the outer straightening plate 24 along the inner straightening plate 23 and the outer straightening plate 24 at predetermined intervals. It is arranged in the shape of ".

The strip levitation characteristics of the chevron pad 12 will be described below.
Causes the fluid supplied to the internal space, such as air, to be ejected from the slit nozzles 21 and the round nozzles 33 and sprayed onto the aluminum strip S. The air ejected from the round nozzle 33 hits the lower surface of the aluminum strip S and forms a kind of air curtain. The adjustment of the gas ejection amount of the round nozzle 33 is performed by adjusting the inner straightening vane 23 or the outer straightening vane 2.
4 is moved in the width direction and the overlapping amount of the round nozzle 33 and the inner straightening plate 23 or the outer straightening plate 24, that is, the opening area of the round nozzle 33 is adjusted.

On the other hand, the fluid ejected from the slit nozzles 21 and 21 in the opposite direction moves in the strip width direction after joining. However, the fluid moving to the side is regulated by the flow regulating member 22 and the air curtain. Further, the inner straightening vane 23 and the outer straightening vane 24 are arranged with their central portions (bent portions) 29, 30 facing outward, and have a strong ability to regulate the fluid escaping toward the ends, and are regulated. The force that holds the fluid in the area surrounded by the left and right flow control members 22 is strong. Therefore, as shown in FIG. 7, a static pressure region P is formed in a wide area between the aluminum strip S and
The levitation force of the aluminum strip S is remarkably stronger than that of the pressure pad 11 having only the slit nozzles 21 and 21.

Next, in the catenary zone Z _C , as shown in FIG. 8, floater nozzles 10 each consisting of a pressure pad 11 and a chevron pad 12 are arranged at predetermined intervals, and the aluminum is placed between the floater nozzles 10. A plurality of round nozzles 13 which are heat transfer nozzles whose main purpose is to transfer heat from the strip S are arranged. The temperature of the gas ejected from the floater nozzle 10 and the round nozzle 13 in the catenary zone Z _C is the temperature required in each zone.

In the continuous heat treatment furnace having the above structure,
Aluminum strip S is waving zone Z of heating zone A
_When loaded into _W , here the chevron pad 12
The upper and lower positions of the pressure pad 11 and the pressure pad 11 are alternately switched. As shown in FIG. 2, the aluminum strip S is conveyed in a non-contact waving state along a sinusoidal curve. As described above, since the waving zone Z _W is provided in the residual stress releasing temperature range of the treated aluminum strip S, the aluminum strip S has a C strain generated before the residual stress is released, that is, when the aluminum strip S is rolled. Alternatively, since the reverse C-zori is waving conveyed in a non-contact state before the increase in the warpage caused by the residual stress being released is superposed, the increase in the C-zor or the reverse C-zor is prevented. Of course, the warpage that occurs during rolling is also reduced.

Thereafter, in the catenary zone Z _C , the aluminum strip S is sprayed from the pressure pad 11 and the chevron pad 12 at the facing portion of the floater nozzle 10 with high-temperature or low-temperature fluid onto the aluminum strip S from above and below, respectively. To be Further, the lower chevron pad 12 is superior to the upper pressure pad 11, which is a conventional nozzle box, in the floatability of the strip, and the chevron pad 12 ejects aluminum from the high or low temperature supporting pressure ejected from the chevron pad 12. The strip S is stably supported in the suspended state. Further, a high temperature or low temperature fluid is sprayed from the round nozzle 13 to be efficiently heated or cooled.

In the above embodiment, the floater nozzle 1
0 is composed of the conventionally known pressure pad 11 and chevron pad 12, but the floater nozzle 10 may be composed of two pressure pads 11. However, since the chevron pad 12 is superior to the pressure pad 11 in the floating stability of the strip, it is preferable to use the chevron pad 12. Further, in the above-described embodiment, the floater nozzle 10 is composed of a pair of pads arranged to face each other, but the pads may be arranged in a staggered pattern above and below the pass line of the aluminum strip S, Furthermore, a pair of upper and lower pads may be arranged in a staggered manner.

On the other hand, except for the waving zone Z _W , instead of the catenary conveyance, a plurality of pairs of pads may be arranged at the same level with a pair of pads interposed therebetween. In this case, as described above, since the amount of warpage of the aluminum strip S is smaller than that of the conventional one, the interval between the opposing pads can be reduced, and the aluminum strip S can be floated and supported in a stable state.
It can be heated and cooled uniformly.

[0019]

As is apparent from the above description, according to the present invention, in continuously heat treating a non-ferrous metal strip, the non-ferrous metal strip is heated in the residual stress release temperature range where the warpage amount of the non-ferrous metal strip increases. Can be conveyed by waving to prevent an increase in warpage caused by residual stress release, and also to correct the warpage produced during rolling. Therefore, following the waving transfer, when supporting the non-ferrous metal strip by levitation with the gas ejected from the nozzle box oppositely arranged, the distance between the nozzle boxes can be made smaller than before, and the non-ferrous metal strip can be stably floated and supported. Moreover, there is an effect that heating and cooling can be performed uniformly.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a non-ferrous metal strip continuous processing furnace.

FIG. 2 is a side view of a waving zone.

FIG. 3 is a plan view of a chevron pad.

FIG. 4 is a cross-sectional view of the chevron pad taken along line IV-IV.

FIG. 5 is a plan view of a flow regulating member.

FIG. 6 is a sectional view taken along line VI-VI of the flow regulating member.

FIG. 7 is a diagram showing a static pressure region of a chevron pad.

FIG. 8 is a side view of the catenary zone.

[Explanation of symbols]

1 ... Continuous heat treatment furnace, 10 ... Floater nozzle, 11 ... Pressure pad, 12 ... Chevron pad, 13 ... Round nozzle, A ... Heating zone, B ... Slow cooling zone, C ... Cooling zone, Z _C
... Katenarizon, Z _W ... waving zone, S ... aluminum strip.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenichi Sasauchi 2-4-7 Kyomachibori Nishi-ku, Osaka City, Osaka Prefecture Chugai Furnace Industry Co., Ltd. No. 18 Sky Aluminum Co., Ltd. (72) Inventor Goro Kitayama 4-3-18 Nihombashi Muromachi, Chuo-ku, Tokyo Sky Aluminum Co., Ltd. (72) Minor Okajima 4-3-18 Nihombashi Muromachi, Chuo-ku, Tokyo No. Within Sky Aluminum Co., Ltd.

Claims (1)

[Claims] 1. A method of continuously heat-treating a non-ferrous metal strip while floating and transporting it in a furnace, wherein the non-ferrous metal strip is transported in a waving state in a residual stress release temperature range of the non-ferrous metal strip on a furnace loading side. A continuous heat treatment method for a non-ferrous metal strip, comprising: