JPH07299502A - Method for joining slab - Google Patents
Method for joining slabInfo
- Publication number
- JPH07299502A JPH07299502A JP9625294A JP9625294A JPH07299502A JP H07299502 A JPH07299502 A JP H07299502A JP 9625294 A JP9625294 A JP 9625294A JP 9625294 A JP9625294 A JP 9625294A JP H07299502 A JPH07299502 A JP H07299502A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- amount
- rolling
- joining
- slab
- 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
Landscapes
- General Induction Heating (AREA)
- Metal Rolling (AREA)
- Pressure Welding/Diffusion-Bonding (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、熱間圧延などにおけ
る鋼片の接合方法に関し、特に良好な接合を行うことの
できる方法を提案しようとするものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of joining steel slabs in hot rolling and the like, and proposes a method capable of particularly favorable joining.
【０００２】[0002]
【従来の技術】従来、熱間圧延ラインにおいては、圧延
すべき鋼片を同時に複数本加熱しておき、この加熱の完
了後、一本ずつ粗圧延次いで仕上圧延を行って所望の板
厚になる熱延板に仕上げていたが、かような圧延方式で
は、仕上圧延の際に、圧延素材の噛み込み不良によるラ
イン停止を惹き起こし易く、また、圧延素材の先端部、
後端部の形状不良に由来した歩留まり低下が大きいた
め、このような問題を回避するために、仕上圧延に先立
ってこれらの鋼片の後端部、先端部を順次につなぎ合わ
せ、これを仕上圧延に連続的に供給する圧延方法の実現
が望まれていた。2. Description of the Related Art Conventionally, in a hot rolling line, a plurality of billets to be rolled are heated at the same time, and after completion of this heating, rough rolling and finish rolling are performed one by one to obtain a desired strip thickness. However, in such a rolling method, it is easy to cause a line stop due to a defective biting of the rolled material, and the leading end portion of the rolled material,
Since the yield decrease due to the defective shape of the rear end is large, in order to avoid such problems, the rear end and the front end of these steel pieces are sequentially joined before finishing rolling, and this is finished. It has been desired to realize a rolling method for continuously supplying to rolling.
【０００３】そのため、先行して圧延に供する鋼片（以
下、先行鋼片という）の後端部と、これに引き続いて圧
延に供する鋼片（以下、後行鋼片という）の先端部とを
接合する方法について、数々の試みがなされてきてい
る。これら種々の試みは、いずれも熱間圧延というプロ
セスに特徴的な工業的、技術的要求や、熱間圧延製品に
特徴的な品質要求を満足しつつ、確実に両鋼片を接合す
る必要があるため、それを意識したものとなっている。Therefore, the rear end portion of the steel piece to be subjected to rolling (hereinafter referred to as the preceding steel piece) and the tip portion of the steel piece to be subsequently subjected to rolling (hereinafter referred to as the trailing steel piece) are provided. Many attempts have been made on the method of joining. In all of these various attempts, it is necessary to reliably join both steel pieces while satisfying the industrial and technical requirements that are characteristic of the hot rolling process and the quality requirements that are characteristic of hot rolling products. Therefore, it is conscious of that.
【０００４】すなわち、熱間圧延では、鋼片の圧延処理
に要する時間が、通常１本につき数十秒程度と、短いサ
イクルタイムであるために、鋼片の後端部、先端部を接
合する処理のために許される時間は数秒〜十数秒程度で
ある。接合処理にそれ以上の時間がかかると、一本当た
りの圧延処理サイクルタイムがいたずらに長時間化する
ことになって生産能率を落とす他、材料の温度が降下し
過ぎて、製品は所望の機械的性質が得られない場合もあ
るからである。That is, in the hot rolling, since the time required for rolling treatment of the steel slabs is a short cycle time, usually about several tens of seconds per steel, the rear end and the tip of the steel slabs are joined. The time allowed for processing is from a few seconds to a dozen seconds. If the joining process takes longer than that, the rolling process cycle time per wire will be unnecessarily lengthened and the production efficiency will be reduced.In addition, the temperature of the material will drop too much, and the product will not reach the desired machine. This is because there are cases in which the physical properties cannot be obtained.
【０００５】さらに、鋼片の接合には、熱間圧延製品の
良好な表面品質を確保すること、あるいは鋼片接合部分
の圧延時にロール表面に疵をつけ、それが被圧延鋼片の
表面に転写されるのを防止すること、といった観点か
ら、鋼片接合部分の接合処理後の形状変化が少ないこ
と、溶鋼飛散あとがない鋼片表面清浄性が確保されるこ
とといった技術的要求もあった。Further, in joining steel billets, ensuring good surface quality of the hot rolled product, or making a flaw on the roll surface during rolling of the billet joining portion, which is caused on the surface of the rolled steel billet. From the viewpoint of preventing transfer, there was also a technical requirement that the shape change of the steel slab joint after the joining process was small and that the steel slab surface cleanliness with no molten steel splattering was secured. .
【０００６】これらの技術的要請を受け、短時間で鋼片
の後端部、先端部を接合することができ、しかも接合処
理後は、鋼片接合部分の形状変化が少なく、溶鋼飛散あ
と等がない鋼片表面清浄性を確保できる鋼片の接合方法
として、熱間圧延設備の入側にて、先行鋼片の後端部及
び後行鋼片の先端部を間隙をあけて対向させ、この対向
させた鋼片の後・先端部を挟んで配置する少なくとも１
対の誘導加熱用コイルから鋼片の厚み方向に貫く交番磁
界をかけることにより生ずる誘導電流によって前記鋼片
の後・先端部を加熱し、互いに向けて押圧して接合する
方法が開発され、特開昭６２−２３４６７９号公報に記
載されている。In response to these technical requirements, it is possible to join the rear end portion and the front end portion of the steel slab in a short time, and after the joining process, there is little change in the shape of the steel slab joint, and after the molten steel is scattered, etc. As a method of joining steel pieces that can ensure the surface cleanliness of the steel pieces, at the entrance side of the hot rolling equipment, the trailing end portion of the preceding steel piece and the leading end portion of the following steel piece are opposed to each other with a gap, At least one of the steel pieces facing each other is arranged so as to sandwich the rear and front ends thereof.
A method has been developed in which the rear and tip portions of the steel slabs are heated by an induction current generated by applying an alternating magnetic field penetrating the steel slab in the thickness direction of the pair of induction heating coils, and pressed toward each other to join them. It is described in Japanese Unexamined Patent Publication No. 62-234679.
【０００７】[0007]
【発明が解決しようとする課題】上掲特開昭６２−２３
４６７９号公報に開示の接合方法においては、誘導加熱
用コイルに生じさせる交番磁界の周波数について、中周
波または高周波を使用するとしており、実施例には、10
kHz 、200 kHz といった高周波の場合が示されている。
周波数を高くすることの有利な点は、周波数を上げれば
上げるほど、接合すべき鋼片の突き合わせ端面からほん
のわずかな深さに誘導電流が集中して流れるため、効果
的に短時間で加熱できるとされている。具体的に、この
誘導電流が集中して流れる厚みを浸透深さで示すと、10
kHz の場合は浸透深さが５mm、200kHz の場合は、浸透
深さが1.1 mmである。なお、この浸透深さの定義は、
「平面の表面を有する半無限導体において、全誘導電流
が平面導体表面における電流密度で一様に分布したと仮
定したときの表面からの深さであり、換言すれば誘導電
流密度が表面の電流密度の１／ｅ（ｅは自然対数の底）
になる深さｐ ｐ＝（πμσｆ）-1/2 （ここに、μ：透磁率(H/m) 、σ：導電率(S/m) 、ｆ：
交番磁界周波数(Hz)）」である。なお鋼片は、正確には
矩形の形状を有し、平面の表面を有する半無限体とは異
なるが、近似的に半無限体と見なして半無限体時に定義
される浸透深さを、計算に用いても差し支えない。[Problems to be Solved by the Invention] Japanese Patent Laid-Open No. 62-23
In the joining method disclosed in Japanese Patent No. 4679, a medium frequency or a high frequency is used as the frequency of the alternating magnetic field generated in the induction heating coil.
High frequency cases such as kHz and 200 kHz are shown.
The advantage of increasing the frequency is that the higher the frequency, the more the induced current concentrates at a slight depth from the butt ends of the steel pieces to be joined, so heating can be performed effectively and in a short time. It is said that. Specifically, if the thickness of the induced current is shown by the penetration depth, it is 10
The penetration depth is 5 mm for kHz and 1.1 mm for 200 kHz. The definition of this penetration depth is
“In a semi-infinite conductor with a flat surface, it is the depth from the surface assuming that the total induced current is evenly distributed at the current density on the surface of the flat conductor. In other words, the induced current density is the current on the surface. 1 / e of density (e is the base of natural logarithm)
Depth p p = (πμσf) -1/2 (where μ: permeability (H / m), σ: conductivity (S / m), f:
Alternating magnetic field frequency (Hz)) ". Note that the steel billet has a rectangular shape to be precise and is different from a semi-infinite body having a flat surface, but it is approximately regarded as a semi-infinite body and the penetration depth defined when the semi-infinite body is calculated. It can be used for.
【０００８】他方、このような突き合わせ端面は、あら
かじめシャーにより切り整えられたものであり、そのた
め、縦断面（鋼片の長手方向に沿って切断した断面）で
みると、シャーの種類の如何を問わず、長手方向に突き
出した形状になるのが普通である。したがって、この突
き合わせ端面に集中して流れる誘導電流は、この突き出
し形状にならった表面のわずかな厚みにのみ流れ、加熱
されるから、鋼片長手方向に突き出した量に釣り合う量
だけ加熱・軟化されない場合、接合すべき鋼片を互いに
向けて押圧する際には、鋼片同士が鋼片長手方向に加熱
・軟化した分だけしか接合できず、板厚方向にわたって
十分な接合強度を確保できないという問題があった。On the other hand, such a butt end face is cut and trimmed in advance by a shear, and therefore, when viewed in a vertical cross section (a cross section cut along the longitudinal direction of the steel slab), it does not depend on the type of the shear. Regardless, it usually has a shape protruding in the longitudinal direction. Therefore, the induced current concentratedly flowing on the butt end face flows only to the slight thickness of the surface having the protruding shape and is heated, so that it is not heated or softened by an amount commensurate with the protruding amount in the longitudinal direction of the steel piece. In this case, when pressing the steel pieces to be joined toward each other, the steel pieces can be joined only by the amount of heating and softening in the steel piece longitudinal direction, and a sufficient joining strength cannot be ensured in the plate thickness direction. was there.
【０００９】このような状態の鋼片を圧延に供すると、
接合部分の強度が弱くて破断に至る場合があった。ま
た、この接合部分は、局部的に板厚が薄くなっているた
め、その程度が著しい場合には、板厚定常部分からのメ
タルフローにより余肉が倒れ込んできて二重に重なり合
った状態で圧延される結果、板厚がさらに薄くなってし
まい、この部分に張力が集中する。これによっても接合
部分が破断に至る場合があった。いずれの場合も、破断
するのを完全になくさない限り、長時間の圧延操業停止
というトラブルの発生を完全に防止することは不可能で
あるという問題があった。When the steel slab in such a state is subjected to rolling,
In some cases, the strength of the joint was weak, leading to breakage. In addition, since the thickness of the joint is locally thin, if the degree of this is significant, the metal flow from the portion where the thickness is steady causes the excess thickness to collapse and the steel sheet is rolled in a double overlap. As a result, the plate thickness becomes thinner, and the tension concentrates on this portion. This may also lead to breakage of the joint part. In either case, there is a problem that it is impossible to completely prevent the occurrence of the trouble of long-term rolling operation stop unless the fracture is completely eliminated.
【００１０】この発明は、上記の問題を有利に解決する
もので、鋼片厚み方向にわたった十分な接合を行って、
圧延時に破断を招くことのない鋼片の接合方法を提案す
ることを目的とする。The present invention advantageously solves the above-mentioned problems, in which sufficient joining is carried out in the thickness direction of the slabs,
It is an object of the present invention to propose a joining method for steel slabs that does not cause breakage during rolling.
【００１１】[0011]
【課題を解決するための手段】この発明は、熱間圧延設
備の入側にて、先行して圧延に供する鋼片の後端部及び
これに引き続いて圧延に供する鋼片の先端部の平面形状
をそれぞれシャーで整えた後、これらの鋼片を間隙をあ
けて対向させ、この対向させた鋼片の後・先端部に配置
する少なくとも１対の誘導加熱用コイルから鋼片の厚み
方向に貫く交番磁界をかけることにより鋼片に生ずる誘
導電流によって前記鋼片の後・先端部を加熱し、互いに
向けて押圧して接合する方法において、シャーにより整
えた鋼片の後・先端部それぞれの縦断面における突き出
し量以上の押圧変位量を確保することを特徴とする鋼片
の接合方法である。DISCLOSURE OF THE INVENTION The present invention is, on the entrance side of a hot rolling facility, a flat surface of a rear end portion of a steel piece to be subjected to rolling in advance and a tip end portion of a steel piece to be subsequently subjected to rolling. After adjusting the shapes with shears, these steel pieces are made to face each other with a gap, and at least one pair of induction heating coils placed at the rear and tip of the opposed steel pieces are arranged in the thickness direction of the steel pieces. In the method of heating the rear and tip portions of the steel pieces by the induced current generated in the steel pieces by applying an alternating magnetic field that penetrates them, and pressing them toward each other to join, the rear and tip portions of the steel pieces arranged by a shear It is a method for joining steel pieces, characterized in that a pressing displacement amount equal to or more than a protrusion amount in a longitudinal section is secured.
【００１２】かような押圧変位量を確保するには、誘導
電流の浸透深さｐを調整して、上記突き出し量の1.0 倍
以上にすれば良い。好適には、誘導電流の浸透深さを突
き出し量の２倍以上、より好適には、３倍以上にする。In order to secure such a pressing displacement amount, the penetration depth p of the induced current may be adjusted so as to be 1.0 times or more the protruding amount. Preferably, the penetration depth of the induced current is twice or more the protrusion amount, and more preferably 3 times or more.
【００１３】上記のような誘導電流の浸透深さと突き出
し量との関係を満足させるには、誘導加熱用コイルに生
じさせる交番磁界の周波数を調整すればよい。その好適
な周波数は、4200Hz以下であり、より好ましくは、１kH
z 以下である。In order to satisfy the relationship between the penetration depth of the induction current and the protrusion amount as described above, the frequency of the alternating magnetic field generated in the induction heating coil may be adjusted. The preferred frequency is 4200 Hz or less, more preferably 1 kHz
It is less than or equal to z.
【００１４】なお、この発明において、突き出し量は、
先行鋼片の後端部及び後行鋼片の先端部のうち、より突
き出ている方の量をいい、また、押圧変位量は、押圧に
際して先行鋼片と後行鋼片とが接触してから、一方又は
双方の鋼片を変位させた変位量の総量をいう。In this invention, the protrusion amount is
Of the trailing end of the preceding steel strip and the leading end of the following steel billet, it refers to the amount that protrudes more.The pressing displacement is the amount of contact between the preceding steel billet and the trailing steel billet during pressing. Therefore, it means the total amount of displacement of one or both steel pieces.
【００１５】[0015]
【作用】以下、図面を用いてこの発明をより具体的に説
明する。図１に、この発明に従う鋼片接合方法の一例を
模式的に示す。図中１は先行鋼片、２は後行鋼片であ
り、この先行鋼片１を、クランプ３a,３b により挟持
し、同様に後行鋼片２を、クランプ４a,４b により挟持
して、先行鋼片１の後端部と後行鋼片２の先端部とが小
ギャップをあけて対向するように配置する。この先行鋼
片１の後端部と後行鋼片２の先端部とが対向している位
置に、これらの鋼片を上下に挟むように一対の誘導加熱
用コイル５を配置し、この誘導加熱用コイル５から鋼片
の厚み方向に貫く交番磁界を印加して先行鋼片１の後端
部及び後行鋼片２の先端部の双方に誘導電流を生起させ
ることによって、先行鋼片１の後端部及び後行鋼片２の
先端部とを加熱する。The present invention will be described in more detail with reference to the drawings. FIG. 1 schematically shows an example of a steel piece joining method according to the present invention. In the figure, 1 is a preceding steel slab, 2 is a trailing steel slab, and this leading steel slab 1 is clamped by the clamps 3a and 3b, and similarly, the following steel slab 2 is clamped by the clamps 4a and 4b. The rear end portion of the preceding steel piece 1 and the front end portion of the following steel piece 2 are arranged so as to face each other with a small gap. At the position where the rear end of the preceding steel slab 1 and the front end of the trailing steel slab 2 face each other, a pair of induction heating coils 5 are arranged so as to sandwich these steel slabs up and down. By applying an alternating magnetic field penetrating in the thickness direction of the billet from the heating coil 5 to generate an induced current in both the rear end portion of the preceding billet 1 and the tip portion of the trailing billet 2, the preceding billet 1 The rear end and the front end of the trailing steel piece 2 are heated.
【００１６】図２に、先行鋼片１の後端部と後行鋼片２
の先端部とを小ギャップをあけて対向させたところを断
面で示す。同図は、ドラムシャーによる切断を行った例
を示しているが、このように、先行鋼片１の後端部及び
後行鋼片２の先端部は、前工程のシャーカットにより突
き出し形状になる。この突き出し量ａの最大値は、鋼片
当たり8.5 mmであった。FIG. 2 shows the trailing edge of the leading steel strip 1 and the trailing steel strip 2.
A cross section shows a portion of the tip of the device facing the other end with a small gap. The figure shows an example of cutting with a drum shear, but in this way, the rear end portion of the preceding steel piece 1 and the leading end portion of the following steel piece 2 are formed in a protruding shape by the shear cut in the previous step. Become. The maximum value of the protrusion amount a was 8.5 mm per steel piece.
【００１７】このような形状になる接合端部を加熱する
際、誘導加熱用コイル５より印加する交番磁界の周波数
を、前掲特開昭６２−２３４６７９号公報の実施例に開
示されたような10kHz あるいは200 kHz といった高周波
で行った場合には、浸透深さがそれぞれ５mm、1.1 mmで
あって、図中６で示す加熱領域が、断面の突き出し部を
ならうような表層に限られる。したがって、鋼片同士を
押圧しても、図３に接合後における接合領域の断面形状
を示すように、鋼片の厚み方向にわたって十分に接合で
きず、これが図４(a) 〜(c) に圧延時における接合領域
の時系列的変化を示すように、局部的に板厚の薄い領域
となって、圧延機７，８間などにて張力Ｔにより圧延時
の破断を招いていたのである。When heating the joint end having such a shape, the frequency of the alternating magnetic field applied from the induction heating coil 5 is set to 10 kHz as disclosed in the embodiment of Japanese Patent Laid-Open No. 234679/1987. Alternatively, when performed at a high frequency of 200 kHz, the penetration depths are 5 mm and 1.1 mm, respectively, and the heating region shown by 6 in the figure is limited to the surface layer that follows the protruding portion of the cross section. Therefore, even if the steel pieces are pressed against each other, as shown in the cross-sectional shape of the joining area after the joining in FIG. 3, the steel pieces cannot be joined sufficiently in the thickness direction of the steel pieces, which is shown in FIGS. 4 (a) to (c). As shown in the time-series change of the joining region during rolling, the region where the plate thickness becomes thin locally causes the breakage during rolling due to the tension T between the rolling mills 7 and 8.
【００１８】そこで、この発明では、上述したような鋼
片が厚み方向にわたって十分に接合できないことに由来
した接合部の破断を解消すべく、シャーにより整えた鋼
片の後・先端部それぞれの縦断面における突き出し量以
上の押圧変位量を確保するのである。このように、突き
出し量以上の押圧変位量を確保する具体的手法として
は、押圧力を高めて、十分に加熱されていない領域まで
も塑性変形させる方法も考えられるが、塑性変形のため
に過大な押圧力を要すること、また、片方の鋼片がもう
片方の板厚方向にずれた状態で接合する場合があって、
この場合、図５(a) 〜(c) に示すように、ずれた部分が
圧延により相手方の鋼片表面に倒れ込み、二重に重なり
合った状態で圧延される結果、板厚が薄くなって張力の
集中により破断に至る場合もあることなどのために有利
とはいえない。前述した問題は、誘導電流の集中する厚
みが鋼片の突き出し量よりも小さいことに起因するので
あるから、この誘導電流を、この突き出し量以上の範囲
で流れるようにすることが有利な方法である。Therefore, in the present invention, in order to eliminate the breakage of the joint portion due to the above-mentioned steel pieces not being able to be sufficiently joined in the thickness direction, longitudinal cutting of each of the rear and tip portions of the steel pieces arranged by a shear is performed. The amount of pressing displacement equal to or greater than the amount of protrusion on the surface is ensured. In this way, as a specific method to secure a pressing displacement amount that is greater than or equal to the protrusion amount, it is possible to increase the pressing force and plastically deform even a region that is not sufficiently heated, but it is excessive due to plastic deformation. It requires a large pressing force, and there is a case where one steel piece is joined in a state where it shifts in the thickness direction of the other,
In this case, as shown in Figs. 5 (a) to (c), the misaligned portion falls down on the surface of the other steel slab due to rolling, and as a result of rolling in a double overlapping state, the sheet thickness becomes thin and the tension It may not be said to be advantageous because it may cause fracture due to the concentration of. The above-mentioned problem is caused by the fact that the thickness where the induced current is concentrated is smaller than the protruding amount of the steel slab.Therefore, it is an advantageous method to make this induced current flow in the range of the protruding amount or more. is there.
【００１９】そこで、鋼片厚み方向にわたって十分な接
合を行うためには、押圧変位量との関係で誘導電流の浸
透深さをどの程度確保すればよいのかを調べた。図６に
その結果を示す。同図から、接合後の接合部引張強度
が、母材の引張強度よりも小さい割合を０にするために
は、誘導電流の浸透深さを少なくとも押圧変位量の1.0
倍にする必要があることが分かる。接合部の引張強度
を、母材の引張強度と同じにするということは、押圧変
位量を突き出し量以上に確保することに他ならないか
ら、鋼片厚み方向にわたって十分な接合を行うために
は、誘導電流の浸透深さを、突き出し量の1.0 倍以上に
することが必要になる。Therefore, in order to perform sufficient joining in the thickness direction of the steel pieces, it was investigated how much the penetration depth of the induced current should be secured in relation to the pressing displacement amount. The results are shown in FIG. From the figure, in order to make the ratio of the tensile strength of the joint after welding smaller than the tensile strength of the base metal to 0, the penetration depth of the induced current should be at least 1.0 of the pressure displacement amount.
You can see that it needs to be doubled. To make the tensile strength of the joint part the same as the tensile strength of the base metal is to ensure that the amount of pressing displacement is equal to or more than the amount of protrusion, so in order to perform sufficient joining in the thickness direction of the billet, It is necessary to make the penetration depth of the induced current more than 1.0 times the protruding amount.
【００２０】図７に、誘導電流の浸透深さと突き出し量
との関係について、接合後の断面で示す。同図(a) は誘
導電流の浸透深さが、突き出し量の1.0 倍の例であり、
同図(b) は、同じく2.0 倍の例、同図(c) は、同じく3.
0 倍の例そして同図(d) は誘導電流の浸透深さが、突き
出し量よりも小さい例である。図７(b) 及び同図(c)か
らも明らかなように、この誘導電流の浸透深さを、突き
出し量の２倍以上にすることは、接合端面から長手方向
へ２倍以上の範囲で加熱されることになるから接合がよ
り確実に行われる。さらに誘導電流の浸透深さを、突き
出し量の３倍以上にすることにより、より負担の少ない
押圧力によって確実に接合することが可能になる。FIG. 7 shows the relationship between the penetration depth of the induced current and the protrusion amount in a cross section after joining. The figure (a) is an example in which the penetration depth of the induced current is 1.0 times the protrusion amount.
The figure (b) is also an example of 2.0 times, and the figure (c) is the same as 3.
The example of 0 times and the same figure (d) are the cases where the penetration depth of the induced current is smaller than the protrusion amount. As is clear from Fig. 7 (b) and Fig. 7 (c), it is necessary to make the penetration depth of the induced current more than twice the protruding amount in the range of more than twice from the joint end face in the longitudinal direction. Since it will be heated, the joining is performed more reliably. Further, by setting the penetration depth of the induced current to be three times or more as large as the protrusion amount, it becomes possible to surely perform the joining with the pressing force with less burden.
【００２１】次に、上記のような誘導電流の浸透深さと
突き出し量との関係を満足するために、この発明で誘導
加熱用コイルに生じさせる交番磁界の周波数を4200Hz以
下と限定したのは、次の理由による。Next, in order to satisfy the relationship between the penetration depth of the induction current and the protrusion amount as described above, the frequency of the alternating magnetic field generated in the induction heating coil is limited to 4200 Hz or less in the present invention. For the following reasons.
【００２２】先行鋼片の後端部や後行鋼片の先端部を、
シャーにて種々の条件により切り整えた場合の、その突
き出し量について調べたところ、どのような条件でも突
き出し量が8.5 mmを超えることはなかった。そこで、こ
の突き出し量の最大値：8.5 mmに対し、先に述べたこと
から誘導電流の浸透深さを、突き出し量の1.0 倍以上に
する。The trailing edge of the preceding billet and the leading edge of the trailing billet are
When the amount of protrusion when trimmed under various conditions in a shear was examined, the amount of protrusion did not exceed 8.5 mm under any conditions. Therefore, with respect to the maximum value of this protrusion amount: 8.5 mm, the penetration depth of the induced current is set to 1.0 times or more of the protrusion amount as described above.
【００２３】これらの条件を、浸透深さの式に当てはめ
る。 浸透深さｐ＝（πμσｆ）-1/2≧1.0 ×8.5 ×10-3 (m) （ここに、μ：透磁率(H/m) 、σ：導電率(S/m) 、ｆ：
交番磁界周波数(Hz)）であり、1000℃の熱間鋼におい
て、μ＝４×3.14×10-7(H/m) 、σ＝１／（120×1
0-8）(S/m) であるから、これらの値を代入して、 ｐ＝［3.14×４×3.14×10-7×｛１／（120 ×10-8）｝
×ｆ］-1/2≧1.0 ×8.5×10-3 ∴ｆ≦4211(Hz)≒4200(Hz)とした。より浸透深さを大き
くして、確実な接合をするのに好ましいのは、1000Hz以
下である。These conditions are applied to the equation of penetration depth. Penetration depth p = (πμσf) -1/2 ≧ 1.0 × 8.5 × 10 -3 (m) (where, μ: permeability (H / m), σ: conductivity (S / m), f:
Alternating magnetic field frequency (Hz)), in hot steel at 1000 ℃, μ = 4 × 3.14 × 10 -7 (H / m), σ = 1 / (120 × 1
0 -8 ) (S / m), these values are substituted, and p = [3.14 × 4 × 3.14 × 10 -7 × {1 / (120 × 10 -8 )}
× f] −1/2 ≧ 1.0 × 8.5 × 10 −3 ∴f ≦ 4211 (Hz) ≈4200 (Hz). It is preferably 1000 Hz or less for increasing the penetration depth and ensuring reliable bonding.
【００２４】一方、誘導加熱用コイルに生じさせる交番
磁界の周波数の下限については、とくに限定するもので
はないが、周波数が低くなるにつれて、浸透深さが長く
なるため、加熱する体積が増加することに対応させる必
要がある。具体的には、投入電力を大きくできるように
電源容量を大きくするか、投入電力はそのままにして加
熱時間を長く確保できるようにライン長さを延長した
り、ルーパでのループ長さを長くするなどの措置を講ず
ることになるが、いずれも設備費が嵩むために現実的な
投資額の許容範囲内に収めることができる条件により周
波数の下限値を決定すればよい。一般的には、300 Hz以
上にするのが好ましい。On the other hand, the lower limit of the frequency of the alternating magnetic field generated in the induction heating coil is not particularly limited, but as the frequency becomes lower, the penetration depth becomes longer, so that the volume to be heated increases. Need to correspond. Specifically, increase the power supply capacity so that the input power can be increased, or extend the line length so that the heating time can be secured for a long time while keeping the input power unchanged, or increase the loop length in the looper. However, since the equipment cost increases, the lower limit value of the frequency may be determined according to the condition that the investment amount can be kept within the practical allowable range. Generally, it is preferable to set it to 300 Hz or higher.
【００２５】[0025]
【実施例】Ｃ：0.004 wt％の極低炭素鋼（厚さ30mm、
幅：1000mm、温度：900 ℃）よりなる先行鋼片及び後行
鋼片の後・先端部をドラムシャーで切り落としたとこ
ろ、突き出し量がいずれも4.5 mmとなった。この先行鋼
片と後行鋼片とを５mmのギャップをあけて対向させ、誘
導加熱用コイルから交番磁界を印加して加熱した。その
条件は、上下コイル間ギャップ：210 mm、交番磁界周波
数：650 Hz、コイル投入電力：1000kW、交番磁界印加時
間：12.5秒であり、交番磁界周波数から計算される浸透
深さは21.6mmである。加熱後、直ちに押圧を変位量５mm
で行って接合したことろ、その後の圧延での破断は皆無
であった。[Example] C: 0.004 wt% ultra low carbon steel (thickness 30 mm,
Width: 1000 mm, temperature: 900 ° C) When the front and rear parts of the leading and trailing steel pieces were cut off with a drum shear, the protrusion amount was 4.5 mm. The preceding steel piece and the following steel piece were made to face each other with a gap of 5 mm, and an alternating magnetic field was applied from the induction heating coil to heat. The conditions are: the gap between the upper and lower coils: 210 mm, alternating magnetic field frequency: 650 Hz, coil input power: 1000 kW, alternating magnetic field application time: 12.5 seconds, and the penetration depth calculated from the alternating magnetic field frequency is 21.6 mm. . Immediately after heating, press the displacement 5 mm
In that case, there was no breakage in the subsequent rolling.
【００２６】[0026]
【発明の効果】この発明は、先行鋼片と後行鋼片とを誘
導加熱し、互いに向けて押圧して接合するに当たり、シ
ャーにより整えた鋼片の後・先端部それぞれの縦断面に
おける突き出し量以上の押圧変位量を確保することによ
り、接合後の圧延に際して板が破断することを完全に防
止することができ、その工業的効果は大である。According to the present invention, when the preceding steel piece and the following steel piece are induction-heated and pressed against each other to join, the protrusions in the longitudinal section of the rear and front end portions of the steel pieces arranged by the shear By securing a pressing displacement amount equal to or more than the amount, it is possible to completely prevent the plate from breaking during rolling after joining, and the industrial effect thereof is great.
【図１】この発明に従う鋼片接合方法の一例示す模式図
である。FIG. 1 is a schematic view showing an example of a steel piece joining method according to the present invention.
【図２】先行鋼片の後端部と後行鋼片の先端部との断面
図である。FIG. 2 is a cross-sectional view of a trailing end portion of a preceding steel piece and a leading end portion of a trailing steel piece.
【図３】接合後における接合領域の断面形状を示す図で
ある。FIG. 3 is a diagram showing a cross-sectional shape of a joining region after joining.
【図４】不十分な接合の場合の、圧延時における接合領
域の時系列的変化を示す図である。FIG. 4 is a diagram showing a time-series change of a joining region during rolling in the case of insufficient joining.
【図５】鋼片同士が板厚方向にずれて接合された場合
の、圧延時における接合領域の時系列的変化を示す図で
ある。FIG. 5 is a diagram showing a time-series change in a joining region during rolling when steel pieces are joined while being displaced from each other in the plate thickness direction.
【図６】誘導電流の浸透深さと押圧変位量との割合が接
合後の引張強度に及ぼす影響を示すグラフである。FIG. 6 is a graph showing the effect of the ratio of the penetration depth of the induced current and the amount of pressure displacement on the tensile strength after joining.
【図７】誘導電流の浸透深さと突き出し量との関係につ
いて、接合後の断面で示す図である。FIG. 7 is a diagram showing a relationship between a penetration depth of an induced current and a protruding amount in a cross section after joining.
１ 先行鋼片 ２ 後行鋼片 ３a 、３b クランプ ４a 、４b クランプ ５ 誘導加熱用コイル ６ 加熱領域 ７ 圧延機 ８ 圧延機 1 Leading steel strip 2 Trailing steel strip 3a, 3b Clamp 4a, 4b Clamp 5 Induction heating coil 6 Heating area 7 Rolling mill 8 Rolling mill
───────────────────────────────────────────────────── フロントページの続き (72)発明者 平林 毅 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 山田 博右 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 二階堂 英幸 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 磯山 茂 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 田村 望 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 天笠 敏明 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 林 寛治 広島県広島市西区観音新町４丁目６番22号 三菱重工業株式会社広島製作所内 (72)発明者 塚田 光政 兵庫県尼崎市塚口本町８丁目１番１号 三 菱電機株式会社尼崎製作所内 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takeshi Hirabayashi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Inside the Chiba Works, Kawasaki Steel Co., Ltd. (72) Hiro right Yamada 1 Kawasaki-cho, Chuo-ku, Chiba Kawasaki Steel Co., Ltd. Chiba Steel Works (72) Inventor Hideyuki Nikaido 1 Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Works (72) Inventor Shigeru Isoyama 1 Kawasaki-cho, Chuo-ku, Chiba City Kawasaki Steel Co., Ltd., Chiba Steel Works (72) Inventor Nozomi Tamura No. 1, Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Co., Ltd., Chiba Steel Works (72) Inventor, Toshiaki Amagasa, Kawasaki-cho, Chuo-ku, Chiba City, Chiba Prefecture Kawasaki Steel Co., Ltd. Chiba Works (72) Inventor Kanji Hayashi 4-6-22 Kannon Shinmachi, Nishi-ku, Hiroshima City, Hiroshima Prefecture Mitsubishi Heavy Industries Stock Association Company Hiroshima Works (72) Inventor Mitsumasa Tsukada 8-1-1 Tsukaguchihonmachi, Amagasaki, Hyogo Sanryo Electric Co., Ltd. Amagasaki Works
Claims (3)
に供する鋼片の後端部及びこれに引き続いて圧延に供す
る鋼片の先端部の平面形状をそれぞれシャーで整えた
後、これらの鋼片を間隙をあけて対向させ、この対向さ
せた鋼片の後・先端部に配置する少なくとも１対の誘導
加熱用コイルから鋼片の厚み方向に貫く交番磁界をかけ
ることにより鋼片に生ずる誘導電流によって前記鋼片の
後・先端部を加熱し、互いに向けて押圧して接合する方
法において、 シャーにより整えた鋼片の後・先端部それぞれの縦断面
における突き出し量以上の押圧変位量を確保することを
特徴とする鋼片の接合方法。1. At the entrance side of a hot rolling facility, after adjusting the plane shape of the rear end of a steel piece to be subjected to rolling in advance and the front end of a steel piece to be subsequently subjected to rolling with a shear, respectively. , These steel pieces are made to face each other with a gap, and an alternating magnetic field penetrating in the thickness direction of the steel piece is applied from at least one pair of induction heating coils arranged at the rear and tip portions of the steel pieces made to face each other. In the method of heating the rear and tip parts of the steel pieces by the induced current generated in the pieces and pressing them toward each other to join them, the amount of protrusion in the longitudinal section of each of the rear and tip parts of the steel pieces arranged by a shear is greater than the amount of protrusion. A method for joining steel slabs, which secures a displacement amount.
る誘導電流の浸透深さｐを、上記突き出し量の1.0 倍以
上にすることにより押圧変位量を確保することを特徴と
する鋼片の接合方法。 記 ｐ＝（πμσｆ）-1/2 （ここに、μ：透磁率(H/m) 、σ：導電率(S/m) 、ｆ：
交番磁界周波数(Hz)）2. The steel piece according to claim 1, wherein the pressing displacement amount is secured by setting the penetration depth p of the induced current calculated by the following formula to 1.0 times or more the protrusion amount. How to join. Note p = (πμσf) -1/2 (where, μ: permeability (H / m), σ: conductivity (S / m), f:
Alternating magnetic field frequency (Hz))
生じさせる交番磁界の周波数を4200Hz以下とすることに
より浸透深さと突き出し量との関係を満足させることを
特徴とする鋼片の接合方法。3. The method according to claim 2, wherein the relationship between the penetration depth and the protrusion amount is satisfied by setting the frequency of the alternating magnetic field generated in the induction heating coil to 4200 Hz or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6096252A JP2905392B2 (en) | 1994-05-10 | 1994-05-10 | How to join billets |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6096252A JP2905392B2 (en) | 1994-05-10 | 1994-05-10 | How to join billets |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07299502A true JPH07299502A (en) | 1995-11-14 |
| JP2905392B2 JP2905392B2 (en) | 1999-06-14 |
Family
ID=14160027
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6096252A Expired - Fee Related JP2905392B2 (en) | 1994-05-10 | 1994-05-10 | How to join billets |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2905392B2 (en) |
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1994
- 1994-05-10 JP JP6096252A patent/JP2905392B2/en not_active Expired - Fee Related
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|---|---|
| JP2905392B2 (en) | 1999-06-14 |
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