JPS631381B2 - - Google Patents
Info
- Publication number
- JPS631381B2 JPS631381B2 JP58148853A JP14885383A JPS631381B2 JP S631381 B2 JPS631381 B2 JP S631381B2 JP 58148853 A JP58148853 A JP 58148853A JP 14885383 A JP14885383 A JP 14885383A JP S631381 B2 JPS631381 B2 JP S631381B2
- Authority
- JP
- Japan
- Prior art keywords
- cooling
- strip
- stress
- roll
- center
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000001816 cooling Methods 0.000 claims description 56
- 238000000034 method Methods 0.000 claims description 6
- 239000002184 metal Substances 0.000 claims description 4
- 230000035882 stress Effects 0.000 description 23
- 239000007789 gas Substances 0.000 description 15
- 229910000831 Steel Inorganic materials 0.000 description 6
- 239000010959 steel Substances 0.000 description 6
- 238000000137 annealing Methods 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000002347 injection Methods 0.000 description 4
- 239000007924 injection Substances 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 230000008646 thermal stress Effects 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000005728 strengthening Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000002791 soaking Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
- C21D9/54—Furnaces for treating strips or wire
- C21D9/56—Continuous furnaces for strip or wire
- C21D9/573—Continuous furnaces for strip or wire with cooling
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Description
【発明の詳細な説明】
この発明は冷却ロールによる金属ストリツプの
冷却方法に関し、絞り等の形状不良を解消するこ
とを目的とする。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of cooling a metal strip using a cooling roll, and an object thereof is to eliminate shape defects such as drawing.
冷却ロールによるストリツプの冷却は連続焼鈍
設備等において使用されているが、冷却過程で生
ずる熱応力のためストリツプの形状がくずれやす
く、甚だしい場合には「絞り」と称するライン方
向の縦じわが生じ、製品不良やストリツプの破断
など重大なトラブルを引起す問題があつた。 Cooling of the strip with a cooling roll is used in continuous annealing equipment, etc., but the shape of the strip tends to be distorted due to the thermal stress generated in the cooling process, and in extreme cases, vertical wrinkles in the line direction called "squeezing" may occur. There were problems that caused serious problems such as product defects and broken strips.
この絞りの原因は、冷却ロールにストリツプが
接触する接触開始点付近の板幅中央に板幅方向の
圧縮応力が発生し、これが「絞り」の引金になる
座屈を起させるためであることが知られている。 The cause of this squeezing is that compressive stress occurs in the widthwise center of the strip near the contact start point where the strip contacts the cooling roll, and this causes buckling that triggers "squeezing". It has been known.
そのため、上記板幅方向の圧縮応力を除去する
ために種々の工夫がなされ提案されている。 Therefore, various efforts have been made and proposed to eliminate the compressive stress in the board width direction.
しかし、本発明者らが実験研究を重ねた結果、
幅方向応力だけではなくライン方向応力も座屈の
発生に大きな影響を及ぼしていることが明らかと
なつてきた。 However, as a result of repeated experimental research by the inventors,
It has become clear that not only the width direction stress but also the line direction stress has a large influence on the occurrence of buckling.
第１図は２軸応力場における薄板の座屈条件を
示すもので、座屈の有無はライン方向及び板幅方
向の応力の両者の状態で決まることがわかる。通
常、冷却ロール接触開始点でのストリツプ応力状
態は第１図のＡ点であるが、もしライン方向応力
がＢ点よりも小さくなると、座屈が生じ、「絞り」
につながる危険が極めて高くなる。 FIG. 1 shows the buckling conditions of a thin plate in a biaxial stress field, and it can be seen that the presence or absence of buckling is determined by the state of stress in both the line direction and the plate width direction. Normally, the strip stress state at the point where the cooling roll starts contacting is point A in Figure 1, but if the stress in the line direction becomes smaller than point B, buckling will occur and "throttling" will occur.
There is an extremely high risk that this will lead to
この第１図が示すものと現場における経験則と
は良く一致している。 There is good agreement between what this Figure 1 shows and the empirical rules in the field.
即ち現場操業においてはストリツプが必ずしも
完全にフラツトではなく耳波、中伸び形状または
エツジドロツプおよび急冷時の熱応力による板幅
中央部のたるみなどのため冷却ロールへのストリ
ツプ接触が不均一になりやすい。そして、不均一
接触により、板幅中央の高い温度分布では実際に
非常に絞りやすいことを経験している。 That is, in on-site operations, the strip is not necessarily completely flat, and the contact of the strip with the cooling roll tends to be uneven due to undulations, elongated shapes, edge drops, and sag in the center of the strip width due to thermal stress during rapid cooling. We have experienced that due to non-uniform contact, it is actually very easy to squeeze in the high temperature distribution at the center of the plate width.
このような現象は、結局板幅中央の高い温度分
布状態ではライン方向応力が中央部で大幅に低下
した状態となり、２軸応力状態が第１図に示す座
屈発生領域に入るためと考えられる。 This phenomenon is thought to be due to the fact that in the high temperature distribution state at the center of the plate width, the stress in the line direction is significantly reduced at the center, and the biaxial stress state enters the buckling region shown in Figure 1. .
本発明は上記した知見に基づいてなされたもの
で、金属ストリツプが冷却ロールに接触する直前
に金属ストリツプの幅方向中央部と冷却し、該中
央部のライン方向応力を板幅両端よりも高めた状
態で冷却ロールに通板せしめるようにしたもので
ある。 The present invention was made based on the above-mentioned knowledge, and the metal strip is cooled at the widthwise central portion of the metal strip immediately before it comes into contact with the cooling roll, so that the stress in the line direction at the central portion is made higher than at both ends of the strip width. The sheet is passed through a cooling roll in the same state.
ここで冷却ロールに接触する直前としたのは次
の理由による。 The reason for setting the time immediately before contacting the cooling roll is as follows.
即ち本発明者らは、現場操業の経験から、「絞
り」の対策として、原板をむしろ耳波傾向にさせ
板幅中央部のライン張力を高めたりする試みや、
また、連続焼鈍においてロール冷却装置の前段に
あるガス強制冷却帯で板幅中央部をより強く冷却
して板幅中央部のライン方向応力を高める実験を
行つてきた。 In other words, based on our experience in on-site operations, the present inventors have attempted to prevent "squeezing" by making the original plate more likely to have an ear wave tendency and increasing the line tension at the center of the plate width.
In addition, in continuous annealing, experiments have been conducted to increase the stress in the line direction at the center of the sheet width by cooling the central portion of the sheet width more strongly in a gas forced cooling zone located before the roll cooling device.
これらの方法によればある程度の効果は得られ
るものの、絞り発生を防止するには至らない。そ
の理由は、一度、板幅中央部のライン方向応力を
高めておいても、ロール接触開始点までの時間が
長いと、せつかくつけたライン方向応力の幅方向
分布が緩和してしまうからである。第２図は鋼の
応力緩和現象を示すグラフであり、薄鋼板をある
応力レベルまで引張つて停止した後の応力の時間
的変化を示している。このグラフから10〜20秒後
には1/2〜1/3の応力レベルまでに減少することが
わかる。 Although these methods provide some effect, they do not prevent the occurrence of throttling. The reason for this is that even if the stress in the line direction at the center of the sheet width is increased, if the time until the roll contact start point is long, the widthwise distribution of the stress in the line direction will be relaxed. be. FIG. 2 is a graph showing the stress relaxation phenomenon of steel, and shows the temporal change in stress after a thin steel plate is pulled to a certain stress level and stopped. This graph shows that the stress level decreases to 1/2 to 1/3 after 10 to 20 seconds.
連続焼鈍においては、ロール冷却帯の前段にガ
スジエツト冷却帯があり、通常700℃から600℃ま
で冷却を行つている。このガスジエツト帯で板幅
中央をより強く冷却し、絞り防止のため、板幅中
央の高いライン張力分布を与えても、10〜20秒後
にロール冷却が行われるため、第２図に示すよう
な応力緩和現象によりその効果は半減されてしま
うわけである。 In continuous annealing, there is a gas jet cooling zone before the roll cooling zone, and cooling is normally performed from 700°C to 600°C. Even if a high line tension distribution is applied at the center of the sheet width to prevent squeezing by cooling the center of the sheet width more strongly with this gas jet zone, roll cooling will occur after 10 to 20 seconds, resulting in a problem as shown in Figure 2. The effect is halved by the stress relaxation phenomenon.
第２図のグラフから、応力緩和による応力低下
の量が比較的小さいのはおよそ２、３秒以内であ
ると考えられる。従つて、板幅中央冷却強化で板
幅中央の高いライン張力分布を与えて、２、３秒
以内に冷却ロールに接触させて冷却すれば、応力
緩和による板幅中央ライン張力の低下はほとんど
起らず、絞り防止効果が十分に発揮される。 From the graph of FIG. 2, it can be seen that the amount of stress reduction due to stress relaxation is relatively small within about 2 to 3 seconds. Therefore, if a high line tension distribution is given at the center of the strip width by strengthening cooling at the center of the strip width, and the strip is cooled by contacting the cooling roll within a few seconds, a decrease in the line tension at the center of the strip width due to stress relaxation will hardly occur. Therefore, the aperture prevention effect is fully exhibited.
これが本発明において直前と限定した理由であ
る。 This is the reason why the present invention is limited to immediately before.
ストリツプ幅方向中央を冷却する手段としては
種々のものが可能であるが、気体又は液体噴射に
よる冷却がその冷却範囲の制御が容易であること
から好ましい。 Although various means are possible for cooling the center in the width direction of the strip, cooling by gas or liquid injection is preferred because the cooling range can be easily controlled.
またストリツプ幅方向中央の冷却は、各冷却ロ
ールの直前においてすべて行う必要はなく、少く
とも１つの冷却ロールの直前において行えば効果
がある。この場合前段側、即ち高温側の冷却ロー
ルほど強度、座屈抵抗が低く、冷却速度が速く熱
応力が大きいことから絞りが発生しやすいため、
なるべく前段側の冷却ロール直前において本発明
を実施するのが望ましい。 Further, cooling of the center in the width direction of the strip does not have to be performed immediately immediately before each cooling roll, but it is effective if it is performed immediately before at least one cooling roll. In this case, the cooling roll on the earlier stage side, that is, the higher temperature side, has lower strength and buckling resistance, faster cooling rate, and higher thermal stress, which makes it easier for drawing to occur.
It is desirable to carry out the present invention immediately before the cooling roll on the front stage side.
第３図に本発明法を連続焼鈍設備におけるロー
ル冷却装置に適用した場合の装置例を示す。 FIG. 3 shows an example of a device in which the method of the present invention is applied to a roll cooling device in continuous annealing equipment.
図中１が＃１から＃５までの冷却ロールであ
り、Ｘが鋼帯である。各冷却ロール１の鋼帯Ｘと
の接触開始点直前に、鋼帯Ｘの幅方向中央部を冷
却するためのノズル１０がNo.１〜No.５まで設置さ
れている。この各ノズル１０はライン方向に３段
に並んだノズルから構成され、ノズル先端から鋼
帯Ｘまで50mm離して並べられている。そしてこの
実施例において各ノズルの板幅方向長さは120mm
となつている。 In the figure, 1 is the cooling roll #1 to #5, and X is the steel strip. Immediately before the contact start point of each cooling roll 1 with the steel strip X, nozzles 10 No. 1 to No. 5 are installed for cooling the central portion of the steel strip X in the width direction. Each nozzle 10 is composed of nozzles arranged in three stages in the line direction, and arranged 50 mm apart from the tip of the nozzle to the steel strip X. In this example, the length of each nozzle in the board width direction is 120 mm.
It is becoming.
ノズル１０から噴射する媒体は、この実施例に
おいて雰囲気ガス（H25％を含むN2ガス）を使
用して、冷却室２内からブロア１１により導出
し、クーラ１２により冷却した上ノズル１０から
このガスを噴射するようにしている。 In this embodiment, the medium injected from the nozzle 10 is drawn out from the cooling chamber 2 by the blower 11 using atmospheric gas (N 2 gas containing 5% H 2 ), and is cooled by the cooler 12 from the upper nozzle 10. This gas is injected.
噴射媒体としては、他のガス或いは水や液体窒
素等の液体を使用してもよく、またこれら液体を
噴霧するようにしても良い。 As the injection medium, other gases or liquids such as water or liquid nitrogen may be used, or these liquids may be sprayed.
なお、ノズル１０は絶えず全数を使用する必要
はなく、ストリツプサイズや通板条件等に応じて
ノズル１０を使いわければ良い。たとえば板厚が
薄く、板幅の広いものほど一般に絞りやすい傾向
があるから、このような場合は、冷却ロール全数
につき、その直前のノズルからガス噴射し、一
方、板が厚く、板幅の狭いものになるに従つて順
次後段の冷却ロール側からガス噴射を停止して行
く。このようにすれば冷却用雰囲気ガスの流量は
少なくて済みそれだけ循環用ブロワー電力負荷が
軽減されるから、運転コスト上も有利である。こ
こで後段側の冷却用ノズルからの噴射を停止する
としたのは上記したように高温側つまり前後側ほ
ど「絞り」やすいからである。 Note that it is not necessary to use all the nozzles 10 all the time, and it is sufficient to use different nozzles 10 depending on the strip size, threading conditions, etc. For example, thinner plates and wider plates generally tend to be easier to squeeze. As the temperature increases, gas injection is sequentially stopped from the cooling roll side at the later stage. In this way, the flow rate of the cooling atmosphere gas can be reduced, and the power load on the circulation blower can be reduced accordingly, which is advantageous in terms of operating costs. The reason for stopping the injection from the cooling nozzles on the latter stage is that, as mentioned above, the higher the temperature, that is, the front and rear sides, the easier it is to "throttle".
次に実施例を示す。 Next, examples will be shown.
実施例
第３図に示す装置を用いてまず初めに冷却ロー
ルだけでストリツプを600℃から400℃まで冷却し
たところ、ストリツプ中央に縦すじ状の絞りが発
生した。その時の通板条件は、ライン速度
100mpm、ストリツプサイズ0.6mm厚×1200mm幅
であつた。絞り防止効果を調べるため、均熱帯直
後のガスジエツト帯で板幅中央部を周りより約20
℃低く冷却したが、「絞り」はほとんど改善され
なかつた。Example When a strip was first cooled from 600° C. to 400° C. using only a cooling roll using the apparatus shown in FIG. 3, a vertical stripe-like constriction occurred in the center of the strip. The threading conditions at that time are line speed
It was 100mpm, and the strip size was 0.6mm thick x 1200mm wide. In order to investigate the effect of preventing shrinkage, the central part of the plate width was separated by about 20 mm from the surrounding area in the gas jet zone immediately after the soaking period.
Although it was cooled to a low temperature, the "aperture" was hardly improved.
次に、このガスジエツト帯での板幅中央冷却強
化をやめ、その代りにロール冷却帯で第１番目の
冷却ロール直前に設置したNo.１ノズルからのみ雰
囲気ガスを全流量400Nm3／ｈ噴射した。その結
果、「絞り」は解消された。 Next, we stopped strengthening the cooling at the center of the sheet width in this gas jet zone, and instead injected atmospheric gas at a total flow rate of 400Nm 3 /h only from the No. 1 nozzle installed just before the first cooling roll in the roll cooling zone. . As a result, the "aperture" was eliminated.
次にノズル１０による冷却後、冷却ロール１に
接触するまでの時間とストリツプ形状不良の発生
との関係を調べた。 Next, the relationship between the time required for contacting the cooling roll 1 after cooling by the nozzle 10 and occurrence of strip shape defects was investigated.
即ち、第３図において、No.１ノズルと＃１冷却
ロールを用いてＬを変化させて操業を行つた。雰
囲気ガスは全流量400Nm3／ｈをNo.１ノズルのみ
から噴射し、その他の条件も上記条件と同じとし
た。 That is, in FIG. 3, the operation was carried out by changing L using the No. 1 nozzle and the #1 cooling roll. Atmospheric gas was injected only from No. 1 nozzle at a total flow rate of 400 Nm 3 /h, and other conditions were the same as above.
この結果を第４図に示す。ここで時間ｔは距離
Ｌの通過時間である。 The results are shown in FIG. Here, the time t is the time taken for the distance L to pass.
このグラフからわかるように、時間ｔ＝２〜３
秒の範囲では、「絞り」は発生せず、軽度の中伸
び状態でロール冷却帯を通過し、この時は、過時
効処理後、スキンパスで十分形状矯正できるもの
であつた。時間ｔが２秒以下であれば板は全くフ
ラツトに冷却ロールに接触し、非常に良好な形状
のまま過時効処理帯に入り、良形状の製品が得ら
れた。 As you can see from this graph, time t=2~3
In the second range, "squeezing" did not occur, and the material passed through the roll cooling zone in a light, medium-stretched state, and at this time, the shape could be sufficiently corrected by a skin pass after the overaging treatment. When the time t was 2 seconds or less, the plate contacted the cooling roll completely flatly and entered the overaging treatment zone with a very good shape, resulting in a product with a good shape.
なお、冷却ロール直前のガス冷却の板幅方向範
囲は、板幅中央、板幅の1/3〜1/15であれば効果
が十分に発揮されることが現場実験で確認され
た。 In addition, field experiments have confirmed that gas cooling immediately before the cooling roll can be sufficiently effective if the range in the sheet width direction is at the center of the sheet width, from 1/3 to 1/15 of the sheet width.
第１図は絞り発生の説明図、第２図は応力緩和
状態を示すグラフ、第３図は本発明方法を実施す
るための装置例を示す構成図、第４図はストリツ
プ幅方向中央部冷却後の経過時間と形状不良の発
生との関係を示すグラフである。
１……冷却ロール、２……冷却室、１０……ノ
ズル、１１……ブロア、１２……クーラ。
Fig. 1 is an explanatory diagram of the occurrence of aperture, Fig. 2 is a graph showing the state of stress relaxation, Fig. 3 is a configuration diagram showing an example of an apparatus for carrying out the method of the present invention, and Fig. 4 is cooling of the central part in the width direction of the strip. It is a graph showing the relationship between subsequent elapsed time and occurrence of shape defects. 1...Cooling roll, 2...Cooling chamber, 10...Nozzle, 11...Blower, 12...Cooler.
Claims (1)
ストリツプの板幅中央部を冷却することを特徴と
する冷却ロールによる金属ストリツプの冷却方
法。1 Immediately before at least one cooling roll,
A method for cooling a metal strip using a cooling roll, characterized in that the central part of the width of the strip is cooled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14885383A JPS6043438A (en) | 1983-08-16 | 1983-08-16 | Method for cooling metallic strip with cooling roll |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14885383A JPS6043438A (en) | 1983-08-16 | 1983-08-16 | Method for cooling metallic strip with cooling roll |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6043438A JPS6043438A (en) | 1985-03-08 |
| JPS631381B2 true JPS631381B2 (en) | 1988-01-12 |
Family
ID=15462198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14885383A Granted JPS6043438A (en) | 1983-08-16 | 1983-08-16 | Method for cooling metallic strip with cooling roll |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6043438A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58100633A (en) * | 1981-12-08 | 1983-06-15 | Nippon Kokan Kk <Nkk> | Variable crown water cooled roll |
-
1983
- 1983-08-16 JP JP14885383A patent/JPS6043438A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58100633A (en) * | 1981-12-08 | 1983-06-15 | Nippon Kokan Kk <Nkk> | Variable crown water cooled roll |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6043438A (en) | 1985-03-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4052235A (en) | Method of preventing oxidation during water quenching of steel strip | |
| JPS631381B2 (en) | ||
| US4422623A (en) | Apparatus for cooling steel strips to effect continuous annealing | |
| JPH0583619B2 (en) | ||
| JPH0414173B2 (en) | ||
| JP2807134B2 (en) | Gas jet chamber sealing device | |
| JP2820359B2 (en) | Atmosphere adjustment method for continuous annealing furnace | |
| JPS6254373B2 (en) | ||
| JPS63241123A (en) | Cooling method for steel strip | |
| JPS61117233A (en) | Strip cooler in contrinuous annealing furnace | |
| JP2960195B2 (en) | Descaling control method for steel strip | |
| JPS6234811B2 (en) | ||
| JPH0573809B2 (en) | ||
| JPS56102526A (en) | Heat treating apparatus of metallic strip | |
| JPH05263148A (en) | Method for controlling cooling furnace for strip continuous heat treating device | |
| JPS62263818A (en) | Control cooling device for steel plate | |
| JPS6050124A (en) | Method for cooling steel strip with roll | |
| JPS6237699B2 (en) | ||
| JP2003145214A (en) | Method for controlling cooling of hot-rolled strip | |
| JPS59157226A (en) | Method for preventing buckling of steel strip in continuous annealing furnace | |
| JPS60194022A (en) | Method and device for cooling of strip in continuous heat treatment | |
| JPH02153023A (en) | Roll cooling method for steel strip | |
| JPS62164831A (en) | Slit strain relief annealing method | |
| JPH0365410B2 (en) | ||
| JPH04160120A (en) | Rapid cooling device in continuous annealing furnace |