JPH01205028A - Production of thin-web h-shaped steel - Google Patents
Production of thin-web h-shaped steelInfo
- Publication number
- JPH01205028A JPH01205028A JP2770088A JP2770088A JPH01205028A JP H01205028 A JPH01205028 A JP H01205028A JP 2770088 A JP2770088 A JP 2770088A JP 2770088 A JP2770088 A JP 2770088A JP H01205028 A JPH01205028 A JP H01205028A
- Authority
- JP
- Japan
- Prior art keywords
- web
- cooling
- water cooling
- flange
- waves
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 37
- 239000010959 steel Substances 0.000 title claims abstract description 37
- 238000004519 manufacturing process Methods 0.000 title claims description 12
- 238000001816 cooling Methods 0.000 claims abstract description 169
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 109
- 230000035882 stress Effects 0.000 claims abstract description 47
- 238000005096 rolling process Methods 0.000 claims abstract description 31
- 230000008646 thermal stress Effects 0.000 claims abstract description 10
- 239000000498 cooling water Substances 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 claims description 17
- 230000007423 decrease Effects 0.000 abstract description 6
- 239000000463 material Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 6
- 230000009466 transformation Effects 0.000 description 6
- 238000012360 testing method Methods 0.000 description 5
- 230000007704 transition Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000005530 etching Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000013459 approach Methods 0.000 description 1
- 238000012937 correction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000005098 hot rolling Methods 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 230000000452 restraining effect Effects 0.000 description 1
- 239000002436 steel type Substances 0.000 description 1
- 238000004781 supercooling Methods 0.000 description 1
Landscapes
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
ウェブ高さが大きく、フランジ厚に対しウェブ厚が薄い
薄肉ウェブＨ形鋼を熱間圧延によって製造する際のウェ
ブ波発生を防止する製造方法に関するものである。Detailed Description of the Invention (Industrial Field of Application) A manufacturing method for preventing the generation of web waves when manufacturing a thin web H-beam steel with a large web height and a thin web thickness relative to the flange thickness by hot rolling. It is related to.
（従来の技術）
周知の通り断面係数が大きく強度に比して経済性の優れ
た薄肉ウェブＨ形鋼は、圧延による製造方法ではウェブ
波の問題があって市場に供給された例がない。(Prior Art) As is well known, thin-walled web H-section steel, which has a large section modulus and is economical compared to its strength, has never been supplied to the market due to the problem of web waves when manufactured by rolling.
また、溶接法によるビルドアップＨ形鋼ではやはり溶接
歪の問題やコストが高いなどの難点がある。In addition, build-up H-beam steel produced by welding still has drawbacks such as welding distortion and high cost.
さて、圧延製造法によると、一般に前記ウェブ波の発生
は、フランジとウェブとの冷却過程における温度差に起
因する残留応力によって、ウエブの座屈限界を越える圧
縮内部応力がウェブに発生ずるためであって、そのため
フランジとウェブの温度を等しくするような冷却手段が
提案されている。According to the rolling manufacturing method, the occurrence of web waves is generally caused by the generation of compressive internal stress in the web that exceeds the web's buckling limit due to residual stress caused by the temperature difference during the cooling process between the flange and the web. Therefore, cooling means have been proposed to equalize the temperatures of the flange and the web.
しかしながら薄肉ウェブＨ形鋼では、フランジが比較的
厚くしかもウェブが薄（、さらにウェブ高さが高いため
、フランジとウェブの温度差を少なくすることが非常に
困難で、どうしても残留応力が大きくなり、これに対し
ウェブの座屈限界が低いためウェブ波の抑制は極めて困
難である。However, with thin web H-section steel, the flange is relatively thick and the web is thin (and the web height is high, so it is very difficult to reduce the temperature difference between the flange and the web, and residual stress inevitably increases. On the other hand, since the buckling limit of the web is low, it is extremely difficult to suppress web waves.
以下図面に従ってさらに説明する。Further explanation will be given below with reference to the drawings.
第５図（ａｌ、 （ｂ）は薄肉ウェブＨ形鋼のウェブ波
に関する概略説明図である。第５図（ａ）に示す通りウ
ェブｌ、フランジ２ａ、２ｂを存する圧延Ｈ形鋼１ａで
は、フランジ厚ＦＬに比しウェブ厚Ｗ５が薄くさらにウ
ェブ高さＷ）Ｉが高い場合たとえば第５図（ｂｌに示す
如く、熱延は可能であるが、ウェブ１にウェブ波３が生
じて製品になりにくいことは前述の通りである。而して
、本発明において薄肉ウェブＨ形鋼とはウェブ厚Ｗ、と
ウェブ内申Ｕの比Ｗ、、／ｕが０．０１７以下のものを
指し、前記比Ｗ ｔ ／ ｕが０．０１７以上であれば
ウェブ波が発生しに＜ ＜ 、０．０１７以下になると
経験的にウェブ波が発生することを知見している。5(a) and 5(b) are schematic explanatory diagrams regarding web waves in a thin-walled H-section steel.As shown in FIG. If the web thickness W5 is thinner than the flange thickness FL and the web height W)I is high, for example, as shown in FIG. As mentioned above, the thin web H section steel in the present invention refers to one in which the ratio W, /u of the web thickness W and the web internal ratio U is 0.017 or less. It has been empirically known that if the ratio W t / u is 0.017 or more, web waves are generated. If the ratio W t / u is 0.017 or less, web waves are generated.
ウェブ波の発生はウェブ座屈によるもので、ウェブ座屈
応力は前記比Ｗ、／ｕの自乗即ち（Ｗｔ ／ ｕ ）
”に概略比例し、この（Ｗｔ／ｕ）”が３Ｘ１０−’以
下になると通常の熱間圧延−空冷の工程ではウェブ波が
発生する。The generation of web waves is due to web buckling, and the web buckling stress is the square of the ratio W, /u, i.e. (Wt / u).
When this (Wt/u) is less than 3X10-', web waves occur in the normal hot rolling-air cooling process.
次に圧延Ｈ形鋼の残留応力の発生につき定性的に説明す
る。Next, the generation of residual stress in rolled H-section steel will be qualitatively explained.
第６図（ａ）は圧延終了後の放冷経過時間に対するフラ
ンジ温度４とウェブ温度５、およびフランジとウェブの
温度差６の推移を示し、第６図（ｂ）は内部応力（圧縮
を正、引張りを負で示す）の変化を模式的に示したもの
で７はフランジの応力、８はウェブの応力、９はウェブ
の降伏応力、１０はフランジの引張り側の降伏応力を表
している。放冷中め温度推移は断面各部が不均一に冷却
されるため、変態開始の時間的ずれが生じその推移状況
は複雑である。大きな特徴としてはフランジ温度４が変
態を終了する時間Ａの近傍でフランジとウェブの温度差
６はピークを示し、その後漸減しつつ、フランジとウェ
ブの温度は接近していく。内部応力はフランジがＡｒ＋
変態を終了する時間Ａの近傍においてはフランジの変態
膨張をウェブが拘束するため、フランジ応カフは圧縮応
力、ウェブ応力８は引張り応力となる。Figure 6 (a) shows the changes in flange temperature 4, web temperature 5, and temperature difference 6 between the flange and web with respect to the elapsed cooling time after the end of rolling, and Figure 6 (b) shows the internal stress (compression , tension is shown as negative), 7 is the stress of the flange, 8 is the stress of the web, 9 is the yield stress of the web, and 10 is the yield stress on the tension side of the flange. In the case of medium temperature transition during cooling, each part of the cross section is cooled non-uniformly, so there is a time lag in the start of transformation, and the transition situation is complicated. The major feature is that the temperature difference 6 between the flange and the web peaks near the time A when the flange temperature 4 completes transformation, and then gradually decreases while the temperatures of the flange and the web approach each other. The internal stress is Ar+ for the flange.
Near the time A when the transformation ends, the web restrains the transformation expansion of the flange, so the flange response cuff becomes a compressive stress and the web stress 8 becomes a tensile stress.
フランジがＡｒ、変態を終了した後はフランジとウェブ
との温度差６が小さくなるに従がい、フランジに引張り
、ウェブに圧縮の応力が蓄積していくが、一般にウェブ
の断面積はフランジの断面積より小さ（、従ってウェブ
の圧縮応力はフランジの引張り応力よりも絶対値は大き
くなる。冷却がさらに進みウェブの圧縮応力８は時間Ｂ
において降伏応力９に点イで達すると、その後はほぼ降
伏応力に等しい値で推移する。常温Ｃの段階ではウェブ
とフランジにはそれぞれ点口、点ハで示す大きさの応力
が残留応力となる。After the flange undergoes Ar transformation, as the temperature difference 6 between the flange and the web decreases, tensile stress accumulates on the flange and compressive stress accumulates on the web, but generally the cross-sectional area of the web is equal to the cross-sectional area of the flange. area (and, therefore, the absolute value of the compressive stress of the web is larger than the tensile stress of the flange. As the cooling progresses further, the compressive stress 8 of the web increases at time B.
When the yield stress 9 is reached at point A, the value remains approximately equal to the yield stress thereafter. At the stage of normal temperature C, the web and the flange have residual stress of the magnitude shown by points C and D, respectively.
一般に、この残留応力がウェブの座屈応力より大きくな
ると冷却の途中でウェブ波を生じる。Generally, if this residual stress becomes larger than the buckling stress of the web, web waves will occur during cooling.
従来、残留応力を軽減するため、変態終了時間Ａに到達
するまでにウェブとフランジの温度差を少なくする手段
としては、例えば特開昭５０−１３３１１０号公報のウ
ェブ保温法あるいは特開昭４９−４３８１０号公報のフ
ランジ水冷法がある。しかしながら薄肉ウェブＨ形鋼を
製造する場合、単にウェブとフランジの温度差を少なく
するだけでは充分な効果が得られなかった。また、本願
出願人は先に、薄肉ウェブＨ形鋼を製造する具体的な手
段として、特開昭６０−２４８８１８号公報でＨ形鋼を
拘束しながら冷却する手段を提供したが、拘束するため
の設備が大がかりになる難点があった。Conventionally, in order to reduce residual stress, methods for reducing the temperature difference between the web and the flange before the transformation end time A is reached include, for example, the web heat retention method disclosed in JP-A-50-133110, or JP-A-49-1999. There is a flange water cooling method disclosed in Japanese Patent No. 43810. However, when manufacturing a thin web H-section steel, simply reducing the temperature difference between the web and the flange did not provide a sufficient effect. In addition, the applicant of the present application previously provided a means for cooling the H-section steel while restraining it in Japanese Patent Application Laid-Open No. 60-248818 as a specific means for producing a thin web H-section steel. The problem was that the equipment was large-scale.
（発明が解決しようとする課題）
本発明は薄肉ウェブＨ形鋼を圧延によって製造する際に
、ウェブ波の発生を簡単な手段で防止できる製造方法を
提供することを目的とするものである。(Problems to be Solved by the Invention) An object of the present invention is to provide a manufacturing method that can prevent the generation of web waves by simple means when manufacturing a thin web H-section steel by rolling.
（課題を解決するための手段・作用）
熱間仕上げ圧延直後のＨ形鋼のフランジを強制冷却して
薄肉ウェブＩ（形鋼を製造する方法において、強制冷却
中にウェブ波が発生しない水冷直後のフランジとウェブ
の温度差の下限と、強制冷却後常温に至るまでのウェブ
の熱応力がウェブの座屈応力以下となる水冷直後のフラ
ンジとウェブの温度差の上限とをＨ形鋼のサイズおよび
冷却水冷密度毎に予め求めておき、前記温度差の上・下
限内でフランジを強制冷却する方法または強制冷却中に
ウェブ波が発生しな°い水冷時間の上限と、強制冷却後
常温に至るまでのウェブの熱応力がウェブの座屈応力以
下となる水冷時間の下限とをＨ形鋼のサイズおよび冷却
水冷密度毎に予め求めておき、前記水冷時間の上・下限
内でフランジを強制冷却することを要旨とするものであ
る。以下、本発明の手段・作用を詳細に説明する。(Means/effects for solving the problem) Thin-walled web I (in a method for manufacturing a section steel, immediately after water cooling in which web waves do not occur during forced cooling) by forcibly cooling the flange of an H section steel immediately after hot finish rolling. The lower limit of the temperature difference between the flange and the web of and the method of forcibly cooling the flange within the upper and lower limits of the temperature difference, or the upper limit of the water cooling time without generating web waves during forced cooling, and the method of cooling the flange to room temperature after forced cooling. The lower limit of the water cooling time at which the thermal stress of the web is less than the buckling stress of the web is determined in advance for each H-beam size and cooling water cooling density, and the flange is forced within the upper and lower limits of the water cooling time. The gist of this invention is to provide cooling.Hereinafter, the means and effects of the present invention will be explained in detail.
まず、本発明者等はフランジの冷却条件の変更が時間の
経過とともに、フランジおよびウェブの温度、さらには
ウェブ応力にどう影響するか調査した。第７図（ａ）は
仕上げ圧延後のＨ形鋼の空冷および水冷における冷却曲
線の例を示し、第７図（ｂ）は第７図（ａｌの温度変化
に対応するウェブの熱応力の変化を示したものである。First, the present inventors investigated how changing the cooling conditions of the flange affects the temperature of the flange and web, as well as the web stress over time. Fig. 7(a) shows an example of the cooling curve in air cooling and water cooling of the H-beam steel after finish rolling, and Fig. 7(b) shows the change in thermal stress of the web corresponding to the temperature change in Fig. 7(al). This is what is shown.
横軸はウェブ幅方向中央部の温度であり、横軸右方向は
時間の経過とともに高温から低温域へ推移する状態を示
す。曲線１１は空冷の場合のフランジ冷却曲線、曲線１
２〜１４はウェブ温度がＤであった時点からフランジ水
冷を開始した時のフランジの冷却曲線であり、１２は短
時間水冷（水冷終了が温度Ｅまで）、１４は長時間水冷
（水冷終了が温度Ｇまで）、１３は両者中間の水冷時間
（水冷終了が温度Ｆまで）で冷却した場合の各フランジ
の冷却曲線を示す。直線１５はウェブの冷却曲線である
が、ウェブに対しては強制冷却を施さないので空冷・水
冷共通となっている。第７図（ｂ）の曲線１６〜１９は
前記の各冷却曲線１１−１４に対応するウェブの熱応力
推移を示す。また、図中の線２０はウェブの座屈応力を
示し、高温度になるほど小さな値となる。The horizontal axis represents the temperature at the center in the width direction of the web, and the right direction of the horizontal axis indicates a state that changes over time from a high temperature to a low temperature range. Curve 11 is the flange cooling curve for air cooling, curve 1
2 to 14 are the cooling curves of the flange when the flange water cooling was started from the time when the web temperature was D, 12 is a short time water cooling (the end of water cooling is up to temperature E), 14 is a long time water cooling (the end of water cooling is the end of water cooling) (up to temperature G), and 13 shows the cooling curve of each flange when cooling is performed with a water cooling time intermediate between the two (water cooling ends up to temperature F). The straight line 15 is the web cooling curve, but since the web is not forcedly cooled, it is common to both air cooling and water cooling. Curves 16 to 19 in FIG. 7(b) show the thermal stress transition of the web corresponding to each of the cooling curves 11 to 14 described above. Further, a line 20 in the figure indicates the buckling stress of the web, and the value becomes smaller as the temperature becomes higher.
ところで、ウェブ波は前記したようにウェブの座屈限界
を越える圧縮内部応力がウェブに生じた時に発生するか
ら、第７図の空冷の場合の熱応力１６は温度低下につれ
て圧縮応力が増大し、点二において座屈応力２０に達し
、ウェブ波が発生することになる。フランジ水冷材の熱
応力を示す曲線１７〜１９で共通していることは、水冷
中にフランジとウェブの温度差が小さくなるに従い圧縮
応力が増大するが、水冷を終了すると一旦引張り側へ変
化した後、再び圧縮側へ変化する。これは水冷により縮
小されたフランジとウェブの温度差が、水冷後−旦拡大
し、縮小するためである。水冷中のウェブの圧縮応力は
点ト、へ、ホで示すように、水冷時間が長いほど大きく
、逆に常温の圧縮応力は点ヌ、す、チで示すように水冷
時間が長いほど小さくなる。上記の短・中・長の各水冷
時間条件のうちで冷却時間の長い応力推移曲線１９の水
冷中の応力は点ルで座屈応力２０に達しており、水冷中
にウェブ波が発生する。また、冷却時間が短い応力曲線
１７の場合、水冷中の熱応力のピーク点ホは座屈応力２
０以下であり、水冷中にウェブ波が発生することはない
が、水冷終了後常温に至る途中の点ヲで座屈応力２０に
達し、ウェブ波が発生ずることが分かった。即ち、水冷
程度が強すぎる場合は水冷中に、また水冷程度か弱すぎ
る場合には水冷後常温に至るまでの間にウェブ波が発生
している。そして、中間の水冷時間の場合の熱応力推移
１８は水冷中および水冷後常温に至るまで座屈応力以下
であり、この条件のもとでウェブ波を防止することが可
能となる。即ち、薄肉ウェブＨ形鋼の場合は、従来サイ
ズのＨ形鋼における残留応力軽減法のように単にフラン
ジとウェブの温度差を縮小するためのフランジ水冷のみ
ではウェブ波を防止す−ることができない。By the way, as described above, web waves are generated when a compressive internal stress exceeding the buckling limit of the web is generated in the web, so the thermal stress 16 in the case of air cooling in FIG. 7 is such that the compressive stress increases as the temperature decreases. A buckling stress 20 is reached at point 2 and a web wave is generated. What is common among curves 17 to 19 showing the thermal stress of flange water-cooled materials is that the compressive stress increases as the temperature difference between the flange and the web decreases during water cooling, but once the water cooling ends, it changes to the tensile side. After that, it changes to the compression side again. This is because the temperature difference between the flange and the web, which was reduced by water cooling, expands and then reduces after water cooling. The compressive stress of the web during water cooling increases as the water cooling time increases, as shown by dots G, H, and H. Conversely, the compressive stress at room temperature decreases as the water cooling time increases, as shown by dots N, S, and C. . Among the above-mentioned short, medium, and long water cooling time conditions, the stress during water cooling in the stress transition curve 19 where the cooling time is long reaches the buckling stress 20 at point Le, and web waves are generated during water cooling. In addition, in the case of stress curve 17 with a short cooling time, the peak point E of the thermal stress during water cooling is the buckling stress 2
0 or less, and no web waves were generated during water cooling, but it was found that a buckling stress of 20 was reached at a point on the way to room temperature after water cooling, and web waves were generated. That is, if the degree of water cooling is too strong, web waves are generated during water cooling, and if the degree of water cooling is too weak, web waves are generated after water cooling until the temperature reaches room temperature. The thermal stress transition 18 in the case of an intermediate water cooling time is less than the buckling stress during and after water cooling until reaching room temperature, and under this condition it is possible to prevent web waves. In other words, in the case of thin-walled web H-section steel, it is not possible to prevent web waves by simply water-cooling the flange to reduce the temperature difference between the flange and the web, as in the residual stress reduction method for conventional size H-section steel. Can not.
第１図Ｔａ）は前記適正条件の存在を確認するため、溶
接によって形成した薄肉ウェブＨ形鋼を試験材として加
熱・冷却実験を行い、冷却中に発生するウェブ波の発生
状況を示したものであり、試験材のサイズはＨ３Ｏ４ｘ
１９５ ｘ６／１９、鋼種は５Ｓ４１である。この試験
材を８５０℃の加熱炉の中で加熱し抽出後、ウェブ中央
部温度が６３０°Ｃになった時点で水量密度を１ ｓ
ｏ ｔｔ／＝・ｍｉｎとしてフランジ外面のみの水冷を
開始した。横軸は水冷終了時のフランジとウェブの温度
差を示し、温度測定は、フランジおよびウェブ幅方向中
央部の板厚中心に熱電対を取付けて行った。縦軸は第１
図（ｂ）に示すウェブ波２１の高さａを示す（振幅×２
）。本来、ウェブ波の程度を正確に表すには急峻度即ち
、（ウェブ波高さａ／波長λ）を採用するべきであるが
、実際に測定した結果、いずれの試験材においても波長
λがほぼ等しかったので、単にウェブ波高さによってウ
ェブ波の程度を評価した。・印は水冷直後のウェブ波を
、○印は常温まで冷却後のウェブ波を測定した結果であ
り、破線２２および実線２３はそれぞれの傾向を示した
ものである。In order to confirm the existence of the above-mentioned appropriate conditions, Fig. 1 Ta) shows a heating/cooling experiment using a thin web H section steel formed by welding as a test material, and shows the occurrence of web waves during cooling. and the size of the test material is H3O4x
195 x 6/19, steel type is 5S41. After heating and extracting this test material in a heating furnace at 850°C, the water density was reduced to 1 s when the temperature at the center of the web reached 630°C.
Water cooling of only the outer surface of the flange was started with ott/=min. The horizontal axis indicates the temperature difference between the flange and the web at the end of water cooling, and the temperature was measured by attaching a thermocouple at the center of the plate thickness at the center of the flange and web in the width direction. The vertical axis is the first
Indicates the height a of the web wave 21 shown in Figure (b) (amplitude x 2
). Originally, to accurately express the degree of web waves, the steepness, that is, (web wave height a/wavelength λ) should be used, but as a result of actual measurements, the wavelength λ was almost the same for all test materials. Therefore, the degree of web waves was evaluated simply by the web wave height. - The mark indicates the result of measuring the web wave immediately after water cooling, and the mark ○ indicates the result of measuring the web wave after cooling to room temperature. The broken line 22 and the solid line 23 indicate the respective trends.
第１図（ａｌにより、水冷終了時のフランジとウェブの
温度差が約２５℃以下になるような強冷却を行うと、水
冷中にウェブ波が発生し、ウェブ波は常温まで冷却後も
残留することが明らかである。温度差が負の領域では水
冷中のウェブ波よりも常温での波が小さくなっているの
は、フランジとウェブの温度が逆転したため、水冷後は
フランジの収縮量よりもウェブの収縮量が大きくなるた
めである。また、温度差が約７５℃以上の軽い冷却の場
合は水冷中にはウェブ波は発生しないが常温ではウェブ
波が残留しており、水冷不足であることを示している。Figure 1 (al) If strong cooling is performed such that the temperature difference between the flange and the web at the end of water cooling is approximately 25°C or less, web waves will be generated during water cooling, and the web waves will remain even after cooling to room temperature. It is clear that in the region where the temperature difference is negative, the waves at room temperature are smaller than the web waves during water cooling, because the temperatures of the flange and web are reversed, so the amount of shrinkage of the flange after water cooling is smaller than that of the web waves during water cooling. Also, in the case of light cooling with a temperature difference of about 75°C or more, web waves do not occur during water cooling, but web waves remain at room temperature, resulting in insufficient water cooling. It shows that there is.
結局、水冷終了時のフランジとウェブの温度差がおよそ
２５〜７５℃の範囲においては、ウェブ波は皆無もしく
は微小であることが判る。本発明では上記のとおり、水
冷終了時のフランジとウェブの温度差が一定範囲内にな
るように冷却制御してウェブ波を防止することを要旨と
する。As a result, it can be seen that when the temperature difference between the flange and the web at the end of water cooling is in the range of about 25 to 75°C, there are no or very small web waves. As described above, the gist of the present invention is to prevent web waves by controlling cooling so that the temperature difference between the flange and the web at the end of water cooling is within a certain range.
冷却制御の条件は水冷開始時の温度条件、水■密度およ
びＨ形鋼のサイズによって異なる。また、実際の操業に
おいては強制冷却直後の温度を把握する方法の他、水冷
時間によって制御するのも実用的であり、以下その具体
的な手順を説明する。Cooling control conditions vary depending on the temperature conditions at the start of water cooling, the water density, and the size of the H-shaped steel. Furthermore, in actual operation, in addition to the method of grasping the temperature immediately after forced cooling, it is also practical to control by water cooling time, and the specific procedure will be explained below.
第２図は本発明法を実施するための装置例であり、本発
明は基本的には仕上げユニバーサル圧延機２５の直後に
フランジ水冷装置２８を設けるのみで可能であるが、こ
の装置例では仕上げ水冷前に予備水冷をした場合との比
較を行うため、中間ユニバーサル圧延機２６の前面およ
びフランジ幅圧下を行うエンジング圧延機２７の後面に
もそれぞれ冷却装置２９．３０を設けた。第３図（ａ）
は仕上げ圧延直後の水冷のみの場合のウェブ波の発生状
況を水冷開始時ウェブ温度と水冷時間の関係で図示した
ものである。第３図（ｂ）は中間圧延でフランジの予備
水冷を行った後、仕上げ圧延直後の水冷を行った場合を
示す。水冷開始時ウェブ温度が６５０℃以下のＡグルー
プは仕上げ圧延後、冷却開始まで若干の待機時間を設け
、Ｂグループは仕上げ圧延直後に冷却を開始するように
して水冷開始時の温度を変化させた。対象サイズはＨ３
Ｏ４Ｘ１９５ Ｘ６／１９、鋼種は５Ｓ４１、仕上げ圧
延機後面の水冷装置における水量密度は２００１ｔ／ｒ
ｄ−ｍｉｎとして、フランジ幅のほぼ９０％に冷却水が
衝突するような冷却を行った。グラフ中、Ｏ印はウェブ
波の発生なし、×印はウェブ波有りを示している。FIG. 2 shows an example of an apparatus for carrying out the method of the present invention. Basically, the present invention is possible by simply providing a flange water cooling device 28 immediately after the finishing universal rolling mill 25. In order to make a comparison with the case where preliminary water cooling was performed before water cooling, cooling devices 29 and 30 were also provided on the front surface of the intermediate universal rolling mill 26 and the rear surface of the engine rolling mill 27 that performs flange width reduction. Figure 3(a)
Figure 2 illustrates the occurrence of web waves in the case of only water cooling immediately after finish rolling in terms of the relationship between the web temperature at the start of water cooling and the water cooling time. FIG. 3(b) shows a case where the flange is preliminarily water-cooled during intermediate rolling and then water-cooled immediately after finish rolling. Group A, whose web temperature at the start of water cooling was 650°C or lower, had a slight waiting time after finish rolling before starting cooling, and group B, where the web temperature at the start of water cooling was changed, by starting cooling immediately after finishing rolling. . Target size is H3
O4X195
Cooling was performed such that cooling water impinged on approximately 90% of the flange width as d-min. In the graph, an O mark indicates that no web waves are generated, and an x mark indicates that a web wave is present.
ウェブ波を防止できる適正な水冷時間の範囲は第３図（
ａｌにおいては曲線３１と３２の間、第３図（ｂ）にお
いては曲線３３と３４の間であることを示している。即
ち、曲線３１．３３未満の水冷時間では水冷中にはウェ
ブ波は生じないが、水冷後常温に至るまでの間にウェブ
波が発生するいわゆる冷却不足の範囲であり、一方、曲
線３２．３４を超える水冷時間では水冷中にウェブ波が
発生し、常温においてウェブ波が残留するいわゆる過冷
却の範囲である。即ち、本発明で言う、水冷後常温に至
るまでの間にウェブ波が発生しない下限の水冷時間とは
曲線３１．３３を意味し、水冷中にウェブ波が発生しな
い上限の水冷時間とは曲線３２．３４を意味する。また
、第３図［ａ）、 （ｂ）によって、適正な水冷時間範
囲は水冷開始時の温度が高いほど広く、また中間圧延段
階で予備水冷を行って予めフランジとウェブの温度差を
縮小しておくと、適正水冷時間の上・下限が共に短時間
側に移動することが判る。予備水冷を行うと、冷却帯を
一方向に通過するだけの水冷方式の場合、仕上げ圧延後
の水冷設備の長さを短く構成でき、あるいは通過速度を
速められるので生産性の向上効果を期待できる。The appropriate range of water cooling time that can prevent web waves is shown in Figure 3 (
al shows that it is between curves 31 and 32, and FIG. 3(b) shows that it is between curves 33 and 34. In other words, when the water cooling time is less than curve 31.33, web waves do not occur during water cooling, but web waves occur after water cooling until the temperature reaches room temperature, which is a so-called insufficient cooling range; If the water-cooling time exceeds 1, web waves are generated during water-cooling, and the web waves remain at room temperature, which is the so-called supercooling range. That is, in the present invention, the lower limit water cooling time during which web waves do not occur during water cooling to room temperature means curve 31.33, and the upper limit water cooling time during which web waves do not occur during water cooling means curve 31.33. It means 32.34. In addition, as shown in Fig. 3 [a] and (b), the appropriate water cooling time range is wider as the temperature at the start of water cooling is higher, and preliminary water cooling is performed at the intermediate rolling stage to reduce the temperature difference between the flange and the web in advance. It can be seen that both the upper and lower limits of the appropriate water cooling time move towards the short time side. If preliminary water cooling is used, the length of the water cooling equipment after finish rolling can be shortened or the passing speed can be increased in the case of a water cooling method in which the material passes through the cooling zone in one direction, which can be expected to improve productivity. .
ウェブ波を発生させないための適正な水冷時間は、上述
のとおり水冷開始時のウェブ温度条件の他に、Ｉ（形鋼
のサイズおよび冷却水量密度条件によって決定されるの
で、Ｉ］形鋼のサイズおよび冷却水量密度毎に第３図で
示した関係を予め把握しておけばよいことになる。第４
図は実際の製造ラインにおいて、仕上げ圧延直後のフラ
ンジ水冷を行う場合の水冷時間管理点の決め方を図示し
たものであり、フランジ水冷開始ウェブ温度範囲を示す
矢印３５の範囲内において水冷中にウェブ波が発生しな
い上限の水冷時間３６の最小値１＋と、水冷後常温に至
るまでの間にウェブ波が発生しない下限温度３７の最大
値ｔ２とを求めておき、両者の中間の時間を管理点とす
る一点管理によれば、当該サイズの圧延材については水
冷開始温度をその都度測定して決定する必要はない。前
記第３図（ａ）。The appropriate water cooling time to prevent web waves from occurring is determined by the web temperature conditions at the start of water cooling as described above, as well as the size of the section steel and the cooling water amount density conditions. It is only necessary to understand in advance the relationship shown in Figure 3 for each cooling water amount density.
The figure shows how to determine the water cooling time control point when water cooling the flange immediately after finish rolling on an actual production line. The minimum value 1+ of the upper limit water cooling time 36 at which web waves do not occur and the maximum value t2 of the lower limit temperature 37 at which web waves do not occur during the period from water cooling to room temperature are determined, and the time between the two is set as the control point. According to the single-point management, there is no need to measure and determine the water cooling start temperature for rolled materials of the relevant size each time. Said FIG. 3(a).
（ｂ）の例では、−点管理によって水冷時間を設定した
ところ、およそ４５秒と３０秒となった。In the example of (b), when the water cooling time was set by minus point management, it became approximately 45 seconds and 30 seconds.
（実施例）
１（５００Ｘ２００ Ｘ６／１９、鋼種５Ｓ４１の薄肉
ウェブ■（形鋼に対し、仕上げ圧延前の予備水冷の有無
または仕上げ圧延直後でのフランジ水冷有無別にウェブ
波の発生状況を調査した結果を第１表に示す。(Example) 1 (500 x 200 are shown in Table 1.
なお、仕上げ圧延直後のフランジ水冷時の水量密度は２
００１！ ／ ｒｄ・ｍｉｎとした。なお、この実施例
における水冷時間の設定は前記の一点管理によって行っ
たが精度上特に問題はなかった。In addition, the water density during flange water cooling immediately after finish rolling is 2.
001! /rd・min. In this example, the water cooling time was set by the above-mentioned one-point control, but there was no particular problem in terms of accuracy.
各種の条件を変更して試験を試みた結果、〔ウェブ厚み
Ｗｔ／ウェブ内法Ｕ〕が小さいサイズ即ち、ウェブ薄肉
の程度が大きいＨ形鋼では、本発明における適正な水冷
時間の範囲は狭くなり、精度の高い水冷時間の制御が必
要となることが判った。また薄肉ウェブＨ形鋼のサイズ
によっては、前述第４図で説明した水冷中にウェブ波が
発生しない上限の水冷時間の最小値ｔ、が水冷後常温に
至るまでの間にウェブ波が発生しない下限温度の最大値
Ｌ２より小さくなる場合がある。このようなサイズにつ
いては水冷時間の一点管理は出来ないが、水冷開始前の
仕上げ圧延前または後に一旦待機することにより、水冷
開始温度のバラツキを小さくずれば一点管理は可能であ
る。なお、本発明において仕上げ圧延直後に冷却すると
いう意味は、前記のような仕上げ圧延前・後の一旦待機
を行った場合も含むもので施る。−旦待機しない別の手
段として、水冷開始温度の高低に応じて水冷時間を変更
することにより、効果を安定させることができる。As a result of testing with various conditions changed, it was found that for H-beam steel with a small [web thickness Wt/web inner diameter U], that is, with a large degree of web thinning, the range of appropriate water cooling time in the present invention is narrow. Therefore, it was found that highly accurate water cooling time control was required. Also, depending on the size of the thin web H-section steel, the minimum value t of the upper limit water cooling time at which web waves do not occur during water cooling as explained in FIG. There are cases where the lower limit temperature becomes smaller than the maximum value L2. For such sizes, it is not possible to control the water cooling time at one point, but it is possible to control the water cooling time at one point by waiting before or after finish rolling before starting water cooling to reduce the variation in the water cooling start temperature. In addition, in the present invention, the meaning of cooling immediately after finish rolling includes the case where the standby is performed before and after finish rolling as described above. - As another means of not waiting for a while, the effect can be stabilized by changing the water cooling time depending on the height of the water cooling start temperature.
（発明の効果）
従来の圧延法ではウェブ波が発生するため、実用化され
たことがなかった薄肉ウェブＨ形鋼が、本発明法によれ
ば既存の圧延加工装置列に特別な装置を付加することな
く簡単に量産できるので経済的な効果は極めて大きい。(Effect of the invention) Thin web H-section steel, which has never been put to practical use due to the generation of web waves in the conventional rolling method, can be manufactured using the method of the present invention by adding special equipment to the existing rolling equipment row. Since it can be easily mass-produced without any additional steps, the economic effect is extremely large.
第１図（ａｌは本発明の詳細な説明するフランジとウェ
ブの温度差に対するウェブ波の関係を示したグラフ、第
１図（ｂ）はウェブ波の説明図、第２図は本発明を実施
する圧延装置列例の説明図、第３図は本発明の詳細な説
明する水冷開始時ウェブ温度と水冷時間およびウェブ波
の関係を示すグラフ、第４図は第３図を簡単化したグラ
フ、第５図（ａ）は薄肉ウェブＨ形鋼を説明するための
断面略図、第５図（ｂ）はウェブ波を説明するＨ形鋼縦
断面略図、第６図（ａ）はウェブとフランジの温度と時
間経過との関係を示すグラフ、第６図（ｂ）はウェブと
フランジの内部応力と時間経過との関係を示すグラフ、
第７１１ｇ（ａ＋は冷却条件を変化させた場合のウェブ
温度の変化を示すグラフ、第７図（ｂ）は第７図（ａ）
のウェブ温度に対応するウェブ応力の変化を示すグラフ
。
２５；仕上げユニバーサル圧延機、２６；中間ユニバー
サル圧延機、２７；エツジング圧延機、２８．２９．３
０？フランジ水冷装置。
第１図
水冷終了時のフランツとウェブの温度、Ｍｕ第２図
２５：仕１−げユニバーザル用９Ｌ磯
２６；中間ユニバーザル圧延機
２７；エツジング圧延機
２８、２９．３０ ：フランジ水冷装置第３図
水冷開始時ウェブ温度（・Ｃ）
水冷開始時ウェブ温度 （・Ｃ）
第４図
低温−−高温
水冷開始ウェブ温度
第５図
（ａ） （ｂ）
第６図
第７図
手 続 補 正 書
昭和６３年３月２３日Figure 1 (al is a graph showing the relationship of web waves to the temperature difference between the flange and web, which explains the present invention in detail, Figure 1 (b) is an explanatory diagram of web waves, and Figure 2 is a graph showing the relationship between the web wave and the temperature difference between the flange and the web, which explains the present invention in detail. FIG. 3 is a graph showing the relationship between the web temperature at the start of water cooling, the water cooling time, and the web waves to explain the present invention in detail; FIG. 4 is a simplified graph of FIG. 3; Fig. 5(a) is a schematic cross-sectional view of a thin web H-beam steel, Fig. 5(b) is a schematic vertical cross-sectional view of an H-beam steel to explain web waves, and Fig. 6(a) is a schematic cross-sectional view of a thin web H-beam steel. A graph showing the relationship between temperature and the passage of time; FIG. 6(b) is a graph showing the relationship between the internal stress of the web and the flange and the passage of time;
711g (a+ is a graph showing the change in web temperature when the cooling conditions are changed, Fig. 7(b) is the graph shown in Fig. 7(a)
Graph showing the change in web stress in response to web temperature. 25; Finishing universal rolling mill, 26; Intermediate universal rolling mill, 27; Etching rolling mill, 28.29.3
0? Flange water cooling device. Fig. 1 Temperature of flantz and web at the end of water cooling, Mu Fig. 2 25: Finishing universal 9L iso 26; Intermediate universal rolling mill 27; Etching rolling mill 28, 29.30: Flange water cooling device Fig. 3 Web temperature at the start of water cooling (・C) Web temperature at the start of water cooling (・C) Figure 4 Low-temperature - Web temperature at the start of high-temperature water cooling Figure 5 (a) (b) Figure 6 Figure 7 Procedure Correction Book Showa March 23, 1963
Claims (2)
却して薄肉ウェブＨ形鋼を製造する方法において、強制
冷却中にウェブ波が発生しない水冷直後のフランジとウ
ェブの温度差の下限と、強制冷却後常温に至るまでのウ
ェブの熱応力がウェブの座屈応力以下となる水冷直後の
フランジとウェブの温度差の上限とをＨ形鋼のサイズお
よび冷却水冷密度毎に予め求めておき、前記温度差の上
・下限内でフランジを強制冷却することを特徴とする薄
肉ウェブＨ形鋼の製造方法。(1) In the method of producing thin web H-section steel by forced cooling of the flange of H-section steel immediately after hot finish rolling, the lower limit of the temperature difference between the flange and the web immediately after water cooling at which web waves do not occur during forced cooling. and the upper limit of the temperature difference between the flange and the web immediately after water cooling, at which the thermal stress of the web until it reaches room temperature after forced cooling is less than the buckling stress of the web, is determined in advance for each size of H-beam steel and cooling water cooling density. A method for manufacturing a thin web H-section steel, characterized in that the flange is forcibly cooled within the upper and lower limits of the temperature difference.
却して薄肉ウェブＨ形鋼を製造する方法において、強制
冷却中にウェブ波が発生しない水冷時間の上限と、強制
冷却後常温に至るまでのウェブの熱応力がウェブの座屈
応力以下となる水冷時間の下限とをＨ形鋼のサイズおよ
び冷却水冷密度毎に予め求めておき、前記水冷時間の上
・下限内でフランジを強制冷却することを特徴とする薄
肉ウェブＨ形鋼の製造方法。(2) In the method of manufacturing thin-walled H-section steel by forced cooling of the flange of H-section steel immediately after hot finish rolling, the upper limit of the water cooling time during which web waves do not occur during forced cooling and the temperature at room temperature after forced cooling are determined. The lower limit of the water cooling time at which the thermal stress of the web is less than the buckling stress of the web is determined in advance for each H-beam size and cooling water cooling density, and the flange is forced within the upper and lower limits of the water cooling time. A method for manufacturing a thin web H-section steel, which comprises cooling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027700A JPH0756042B2 (en) | 1988-02-10 | 1988-02-10 | Method for manufacturing thin web H-section steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63027700A JPH0756042B2 (en) | 1988-02-10 | 1988-02-10 | Method for manufacturing thin web H-section steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01205028A true JPH01205028A (en) | 1989-08-17 |
| JPH0756042B2 JPH0756042B2 (en) | 1995-06-14 |
Family
ID=12228257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63027700A Expired - Lifetime JPH0756042B2 (en) | 1988-02-10 | 1988-02-10 | Method for manufacturing thin web H-section steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0756042B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03271320A (en) * | 1990-03-20 | 1991-12-03 | Kawasaki Steel Corp | Method and apparatus for cooling thin-walled wide flange shape |
| EP0462783A2 (en) * | 1990-06-21 | 1991-12-27 | Nippon Steel Corporation | Process and apparatus for producing thin-webbed H-beam steel |
| JPH04173919A (en) * | 1990-11-06 | 1992-06-22 | Nippon Steel Corp | Production of thin-web h beam |
| US5259229A (en) * | 1990-06-21 | 1993-11-09 | Nippon Steel Corporation | Apparatus for cooling thin-webbed H-beam steel |
| JP2020157364A (en) * | 2019-03-27 | 2020-10-01 | Ｊｆｅスチール株式会社 | Manufacturing method for h section steel |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5543053A (en) * | 1978-09-22 | 1980-03-26 | Sumitomo Chem Co Ltd | Preparation of optically active gamma-hydroxyundecanoic acid |
-
1988
- 1988-02-10 JP JP63027700A patent/JPH0756042B2/en not_active Expired - Lifetime
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5543053A (en) * | 1978-09-22 | 1980-03-26 | Sumitomo Chem Co Ltd | Preparation of optically active gamma-hydroxyundecanoic acid |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03271320A (en) * | 1990-03-20 | 1991-12-03 | Kawasaki Steel Corp | Method and apparatus for cooling thin-walled wide flange shape |
| JPH0723508B2 (en) * | 1990-03-20 | 1995-03-15 | 川崎製鉄株式会社 | Method and apparatus for cooling thin H-section steel |
| EP0462783A2 (en) * | 1990-06-21 | 1991-12-27 | Nippon Steel Corporation | Process and apparatus for producing thin-webbed H-beam steel |
| US5191778A (en) * | 1990-06-21 | 1993-03-09 | Nippon Steel Corporation | Process for producing thin-webbed h-beam steel |
| US5259229A (en) * | 1990-06-21 | 1993-11-09 | Nippon Steel Corporation | Apparatus for cooling thin-webbed H-beam steel |
| JPH04173919A (en) * | 1990-11-06 | 1992-06-22 | Nippon Steel Corp | Production of thin-web h beam |
| JP2020157364A (en) * | 2019-03-27 | 2020-10-01 | Ｊｆｅスチール株式会社 | Manufacturing method for h section steel |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0756042B2 (en) | 1995-06-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2583295A1 (en) | Process and apparatus for the continuous production of a thin metal strip | |
| JPH1177102A (en) | Method for rolling wide hot strip with cps-equipment and rolling equipment | |
| JPH01205028A (en) | Production of thin-web h-shaped steel | |
| JPH01205810A (en) | Method for preventing generation of scale after descaling | |
| CA2194229C (en) | Bonded pipe and method for bonding pipes | |
| US20020046590A1 (en) | Method and apparatus for reducing and sizing hot rolled ferrous products | |
| JP2861871B2 (en) | Control method of winding temperature of hot rolled steel sheet | |
| JP3238569B2 (en) | Method for controlling winding temperature of hot rolled steel sheet | |
| JP2891131B2 (en) | Necking prevention method in hot rolling | |
| JPH075962B2 (en) | Method for manufacturing thin web H-section steel | |
| JP3282714B2 (en) | Cooling method for hot steel sheet | |
| JPH10113713A (en) | Production of steel plate of controlled cooling | |
| JP2819984B2 (en) | Steel strip cooling method | |
| JP3297593B2 (en) | Joining method of materials to be rolled in continuous hot rolling | |
| JPS5870901A (en) | Reduced crop rolling method in hot rolling | |
| JPH0215816A (en) | Restricting cooling control method for shape steel | |
| JPS6191324A (en) | Induction hardening method | |
| JPH02197312A (en) | Cooling method for hot rolled steel plate | |
| JP2020157364A (en) | Manufacturing method for h section steel | |
| JPS62192242A (en) | Production of continuous casting slab for steel plate having excellent internal soundness | |
| JPS62161402A (en) | Method for decreasing residual stress in web of wide flange beam | |
| JP2001300659A (en) | Tube expanding method for tube material | |
| JPH02211903A (en) | Controlled rolling method for thick steel plate | |
| JPS62235423A (en) | Method and apparatus row for on line shape controlling of shape steel | |
| JPS59129717A (en) | Direct hardening device for steel plate |