JPS58122124A - Forming method of forge welding steel pipe - Google Patents

Abstract

PURPOSE:To prevent twist of a tubular skelp in the circumferential direction, and to heat an edge part efficiently before forge welding, by making the first stand a vertical stand, and providing a seam guide on a roll hole die of a horizontal stand being the second stand, when forming a band-like skelp like a pipe. CONSTITUTION:A band-like skelp 2 is heated to a hot working temperature by a heating furnace 1, is formed like a pipe by forming rolls 3, 4, and skelp edge part 2' is heated to a forge welding temperature by a high frequency induction heating coil 7, is forge-welded by a forge welding roll 5, and a pipe is formed. In this case, the forming roll 3 is made a vertical stand, forming is executed up to 180 deg., the forming roll 4 placed at a distance of 450mm. from the forming roll 3 is made a horizontal stand, a seam guide 8 constituted so that a distance between the skelp edges is about 80mm. is provided on a roll hole die, the skelp edge contacts with the seam guide 8, and twist of the tubular skelp in the circumferential direction is prevented.

Description

【発明の詳細な説明】 本発明は鍛接鋼管の製造工程において、鍛接前の管状ス
ケルプエツジ部を加熱するために、ねじれのない安定し
たスケルプ形状を提供するための成形方法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a forming method for heating a tubular scallop edge portion before forge welding in the manufacturing process of forge welded steel pipes to provide a stable scalp shape without twisting.

従来鍛接鋼管は第１図に示すように、加熱炉・ｌで熱間
加工温度以上加熱された帯状スケルプ２を、垂直スタン
ドの成形ロール３で管状に成形し、鍛接ロール５により
鍛接して絞りロール６で圧延し製造していた。例えば４
４４器巾Ｘ４ＪＩｌ厚の熱間スケルプを成形するには、
ロール径２９１　ｍ　Ｘロール巾２２０龍の成形ロール
で２７００程度成形し。As shown in Fig. 1, conventional forge-welded steel pipes are made by forming a band-shaped skelp 2 heated above the hot working temperature in a heating furnace 1 into a tube shape with a forming roll 3 on a vertical stand, and then forge-welding and drawing with a forge-welding roll 5. It was manufactured by rolling with roll 6. For example 4
To form a hot skelp of 44mm width x 4JIl thickness,
About 2,700 pieces are formed using forming rolls with a roll diameter of 291 m and a roll width of 220 mm.

成形スタンドから４１ｏｎの距離に鍛接ロールを配置し
て管を製造していた。A forge weld roll was placed at a distance of 41 on from the forming stand to manufacture the tube.

しかし従来方法では、スケルプエツジの振れ：を防止す
る方法がなく、安定したスケルプ形状を得ることができ
ないので、鍛接前の管状スケルプを、加熱装置で安定し
て加熱できないという問題がある。加熱装置としては、
高周波誘導加熱やプラズマアーク加熱や酸素−アセチレ
ン加熱等があるが。However, in the conventional method, there is no way to prevent the squelp edge from wobbling, and a stable squelp shape cannot be obtained, so there is a problem that the tubular skelp before forge welding cannot be stably heated with a heating device. As a heating device,
There are high frequency induction heating, plasma arc heating, oxygen-acetylene heating, etc.

いずれの加熱に於いても、ねじれのない安定したスケル
プ形状であることが必要である。In any heating process, it is necessary to have a stable squelp shape without twisting.

例えば第３図に示すような直線型加熱コイル７で、管状
スケルプエツジ部を高周波誘導加熱する場合は、スケル
プエツジ部と加熱コイルの隙間を５Ｂ程度にする必要が
あるが、管状スケルプがねじれると、スケルプエツジ部
と加熱コイルの隙間が変化して、加熱量が変動し所定の
昇温を得ることができなくなったり、更に大きくねじれ
ると、加熱コイルに接触して加熱コイルを損傷するとい
う欠点がある。又プラズマアーク加熱か酸素−アセチレ
ン加熱等に於いても、管状スケルプがねじれると、加熱
装置の加熱方向がスケルプエツジに一致せず、加熱量が
安定しないという欠点があった。For example, when performing high-frequency induction heating on a tubular skelp edge part using a linear heating coil 7 as shown in Fig. 3, the gap between the skelp edge part and the heating coil needs to be approximately 5B. If the gap between the heating coil and the heating coil changes, the amount of heating fluctuates, making it impossible to obtain a predetermined temperature increase, or if the heating coil is twisted even more, the heating coil may come into contact with the heating coil and be damaged. Also, in plasma arc heating, oxygen-acetylene heating, etc., if the tubular squelp is twisted, the heating direction of the heating device will not match the squelp edge, resulting in an unstable heating amount.

本発明は、ｉｔ接接前管状スケルプエツジ部を加装装置
で安定加熱するために、安定したスケルプ形状となる成
形方法の提供を目的とする。SUMMARY OF THE INVENTION The present invention aims to provide a molding method that provides a stable scallop shape in order to stably heat a tubular scallop edge portion before it is brought into contact with a finishing device.

すなわち、本発明は鍛接鋼管加熱炉で加熱された帯状ス
ケルプを、成形ロールで管状に成形し、管状スケルプの
エツジ部を加熱装置で加熱した後、ｕｊ接クロールより
鍛接して管とする鍛接鋼管の製造工程において、上記成
形口ニルで管状に成形するために、成形スタンドを２ス
タンドにし、第１スタンドを垂直スタンドで、第２スタ
ンドを水平スタンドとして、第２スタンドのロール大型
にシームガイドをつけることを特徴とする鍛接鋼管成３
− 次に本発明の構成を第２図に示す望ましい実施例により
、詳細に説明する。That is, the present invention is a forge-welded steel pipe in which a band-shaped skelp heated in a forge-welded steel pipe heating furnace is formed into a tubular shape with forming rolls, the edge portion of the tubular skelp is heated with a heating device, and then forge-welded with a UJ welding roll to form a pipe. In the manufacturing process, in order to form into a tubular shape using the above-mentioned forming hole, there are two forming stands, the first stand is a vertical stand, the second stand is a horizontal stand, and a seam guide is attached to the large roll of the second stand. Forge welded steel pipe formation 3 characterized by
- Next, the configuration of the present invention will be explained in detail with reference to a preferred embodiment shown in FIG.

加熱炉ｌで帯状スケルプ２を、９００℃〜１３００℃の
熱間加工温度に加熱し、成形ロール３および４で管状に
成形し、高周波誘導加熱コイル７によりスケルプエツジ
部２′を、　１３５０℃程度の鍛接温度に加熱した後、
鍛接ロール５により鍛接して管とする。管はその後絞り
ロール６によって絞り加工され、所定の管径に圧延され
る。The strip-shaped skelp 2 is heated in a heating furnace 1 to a hot working temperature of 900°C to 1300°C, formed into a tubular shape with forming rolls 3 and 4, and the skelp edge portion 2' is heated to a temperature of about 1350°C with a high-frequency induction heating coil 7. After heating to forge welding temperature,
The tube is forged by a forge welding roll 5. The tube is then drawn by a drawing roll 6 and rolled to a predetermined tube diameter.

第４図は成形ロール３であり、ロール径４００聴×ロー
ル巾２２０１１１Ｘ成形角１８０°であり、帯状スケル
プを１８０’まで成形する。FIG. 4 shows the forming roll 3, which has a roll diameter of 400mm x roll width of 220111 x forming angle of 180°, and forms a band-shaped skelp up to 180'.

第５図は成形ロール４であり成形ロール３から４５０　
ａｍの距離をもって水平スタンドで配置し、ロール径３
ｏ　ｏｔｍｘロールＩ”ｌ’１２００器でスケルプエツ
ジ間距離を８０Ｍ程度離すようにした大型である。又成
形ロール４の穴型にシームガイド８を付けて、スケルプ
エツジがシームガイドに接触し。Figure 5 shows the forming roll 4, which is 450 from the forming roll 3.
Placed on a horizontal stand with a distance of am, roll diameter 3
o otmx roll I"l' 1200 rolls are used, and the distance between the squelching edges is about 80M. Also, a seam guide 8 is attached to the hole mold of the forming roll 4, so that the squelching edges are in contact with the seam guide.

管状スケルプの円周方向に捩れるのケ防止する。Prevents twisting of the tubular skelp in the circumferential direction.

４− 次に本発明装置の作用を、ｇｚ因に示す実施例により＃
ｉ、ｇＡする。　　　　　′ 成形ロール３の成形角はｌ　８０’ｌｉ度にする必要が
あるが、これより大きくとった場合１例えに２γ００程
度とすると、成形ｇ−ル３による成形でスケルプエツジ
部が大きく伸にされ、成形ｐ−ル３をすき゛てもスケル
プエツジ間距離が減少して。4- Next, the action of the device of the present invention will be explained using an example showing the gz factor.
i,gA. 'The forming angle of the forming roll 3 needs to be 180'li degrees, but if it is larger than this, for example, about 2γ00, the skeleton edge part will be greatly elongated by forming with the forming roll 3, Even if the molding plate 3 is cleared, the distance between the squelp edges decreases.

スケルプエツジ同志が接触するので１Ｍ形ロール３〜絨
Ｍ＃ロール５間を大きくとれない。例えはスケルプ中４
４４腸Ｘ厚４讃を、成形角２フ０°の成形ロール３で成
形すると、成形ロール３〜蛾Ｊｉ。Since the squelp edges come into contact with each other, it is not possible to provide a large space between the 1M type roll 3 and the carpet M# roll 5. For example, 4 in Skelp
When 44 mm x 4 mm is molded with a molding roll 3 with a molding angle of 2 degrees and 0 degrees, the molding roll 3 ~ Moth Ji.

−ル５ｒｋＲは５００■が限度でるり、それ以上の聞１
４をとった場合、ＩＩＩｍ！ロール５の前でスケルプエ
ツジ同志が接触し、鍛接が不可能となる。- The limit for 5rkR is 500■, and anything over that is 1.
If you get 4, IIIm! Skelp edges come into contact with each other in front of roll 5, making forge welding impossible.

又成形角を１２０’１１度に小さくきると、成形ロール
３で左右から力を加えるので、上下方向にスケルプが逃
げるため成形の安定性がない。従って成形ロール３の成
形角は、１８０’近傍とする必要がある。Furthermore, if the forming angle is reduced to 120'11 degrees, force is applied from the left and right sides by the forming rolls 3, and the squelp escapes in the vertical direction, resulting in poor forming stability. Therefore, the forming angle of the forming roll 3 needs to be around 180'.

成形ロール４の穴型にｔｉＪＩ５図に示すように。As shown in tiJI5 diagram on the hole mold of the forming roll 4.

６− シームガイド８を付けて、スケルプエツジがシームガイ
ドに接触して、捩れないようにするために。6- Attach the seam guide 8 to prevent the skelp edge from coming into contact with the seam guide and twisting.

シームガイド８で囲まれる成形ロール大型の成形角度θ
は下式とする。Forming angle θ of large forming roll surrounded by seam guide 8
is the following formula.

Ｒ２：下ロール穴型半径 Ｒ２：上ロール穴型半径 Ｗ　：スケルプ中 ｔ　：スケルプ厚 ΔＬ：余裕長さ ここでΔＬ＝Ｏでは幾可学的にスケルプエツジがシーム
ガイドに接触し、ΔＬ）Ｏではシームガイドに接触せず
ス冴ルプが円周方向に捩れ、ΔしくＯではシームガイド
でスケルプエツジが押圧される。実際上は日−ル穴型と
スケルプが全周に亘って接触しているとは限らないので
、ΔＬは若干の値をもち、Ｏ−０，０２ＸＷとする。R2: Lower roll hole radius R2: Upper roll hole radius W: Skelp middle t: Skelp thickness ΔL: Margin length Here, at ΔL=O, the squelp edge geometrically contacts the seam guide, and at ΔL)O The squelp twists in the circumferential direction without contacting the seam guide, and the seam guide presses the squelp edge in the ∆ angle. In reality, the hole mold and the skelp are not necessarily in contact with each other over the entire circumference, so ΔL has a certain value, and is set to O-0.02XW.

成形ロール４の成形角θは、スケルプ中によつ６− て変える必要があり、スケルプ巾４４４ｍ＋Ｘ厚４朋で
２７０°、巾１７１鰭×厚３Ｂで２２０°程度とする。The forming angle θ of the forming roll 4 needs to be changed during the skelping process, and is approximately 270° for a skelp width of 444 m + thickness of 4 mm, and approximately 220° for a width of 171 fins x thickness of 3 mm.

この理由はロール大型でのスケルプエツジ間距離を８０
ｍ程度にするためには、スケルプ巾が狭い時は、当然成
形角を小さくする必要があるからである。下ロール大型
半径Ｒ２と上ロール穴型半径Ｒ２の比Ｒ２／Ｒ４は１．
５程度とする。The reason for this is that the distance between the scale edges in a large roll is 80
This is because when the squelp width is narrow, it is naturally necessary to make the forming angle small in order to make it approximately m. The ratio R2/R4 of the lower roll large radius R2 and the upper roll hole radius R2 is 1.
It should be around 5.

Ｒ２をＲ，より大きくするのは、スケルプエツジ部の曲
率半径を小さくして、スケルプエツジ部の伸びを小さく
し、成形ロール４出側でのスケルプエツジ線紫はぼ平行
にするためである。成形口〜ル４を水平スタンドにする
のは、成形角が１８０゜を超した場合、垂直スタンドの
ロールには、シームガイドはつけられないので水平スタ
ンドとするものであり、又成形ロール３と鍛接ロール５
間の成形スケルプが、成形を行なう向きへ弓形状に曲る
のを、上下の成形ロールで押さえて防止し、水平にする
ためである。The reason why R2 is made larger than R is to make the radius of curvature of the squelched edge portion small, so that the elongation of the squelched edge portion is made small, and the squelched edge line purple on the exit side of the forming roll 4 is made to be approximately parallel. The reason for using a horizontal stand for the forming opening to roll 4 is that if the forming angle exceeds 180°, a seam guide cannot be attached to the roll on the vertical stand, so it is a horizontal stand. Forge welding roll 5
This is to prevent the molding skelp in between from bending into a bow shape in the direction of molding by pressing it with the upper and lower molding rolls, and to make it horizontal.

鍛接ロール５は、成形ロール４から８００ｎ程度の距離
をもって配置し、成形ロール４とｆａ接ロ７− 一ル５間に配置された加熱装置で、スケルプエツジを加
熱した後、鍛接ロール５で鍛接する。The forge welding roll 5 is arranged at a distance of about 800n from the forming roll 4, and after heating the squelp edge with a heating device placed between the forming roll 4 and the fa welding roll 7-15, the forge welding roll 5 welds it. .

本発明は以上のような構成をもつ成形方法であるから、
第１表に示すごとく、スケルプの捩れを防止して、スケ
ルプエツジ部の円周方向の変動を小さくし、成形ロール
４と鍛接ロール５間距離を大キくとって、スケルプ両エ
ツジ軌跡がほぼ平行にすることによって、鍛接前の′管
状スケルプエツジ部を、加熱装置で安定して効率よく加
熱できる。Since the present invention is a molding method having the above configuration,
As shown in Table 1, twisting of the skelp is prevented, fluctuations in the circumferential direction of the skelp edge portion are reduced, and the distance between the forming roll 4 and forge welding roll 5 is set large, so that the trajectories of both skelp edges are almost parallel. By doing so, the tubular squelp edge portion before forge welding can be stably and efficiently heated by the heating device.

８− ９−8- 9-

【図面の簡単な説明】[Brief explanation of drawings]

第１図は従来の鍛接鋼管製造法の一例を示す説明図、第
２図は本発明による鍛接鋼管製造法の説明図、第３図（
イ）（ロ）は本発明における直線型加熱コイルを示す説
明図、第４図は本発明における成形ロールを示す説明図
、第５図は本発明におけるシームガイド付き成形ロール
を示す説明図である。 １；加熱炉　　　　　　２；帯状スケルプ３；＃１成形
ロール　　４；＃２成形ロール５；鍛接ロール　　　　
７；高周波誘導加熱コ８；シームガイド　　　　　イル 一１〇− 第３　＠　（イ９ Ｉ 第４図 算３　図（ロ） 第５図FIG. 1 is an explanatory diagram showing an example of a conventional forge-welded steel pipe manufacturing method, FIG. 2 is an explanatory diagram of a forge-welded steel pipe manufacturing method according to the present invention, and FIG.
A) (B) is an explanatory view showing a linear heating coil in the present invention, Fig. 4 is an explanatory view showing a forming roll in the present invention, and Fig. 5 is an explanatory view showing a forming roll with a seam guide in the present invention. . 1; Heating furnace 2; Belt-shaped squelp 3; #1 forming roll 4; #2 forming roll 5; Forge welding roll
7; High frequency induction heating 8; Seam guide 110-3 @ (A9 I 4th diagram 3 Figure (b) Figure 5

Claims (1)

【特許請求の範囲】[Claims] 鍛接鋼管加熱炉で加熱された帯状スケルプを、成形ロー
ルで管状に成形し、管状スケルプのエツジ部を再度加熱
装置で加熱した後、鍛接ロールにより鍛接して管とする
鍛接鋼管の製造工程において、上記成形ロールで管状に
成形するために、成形スタンドを２スタンドにし、第１
スタンドを垂直スタンドで、第２スタンドを水平スタン
ドとして、第２スタンドのロール大型にシームガイドを
付けることを特徴とする鍛接鋼管成形方法。In the manufacturing process of forge-welded steel pipes, the strip-shaped skelp heated in a forge-welded steel pipe heating furnace is formed into a tubular shape with forming rolls, the edge portion of the tubular skelp is heated again with a heating device, and then forge-welded with a forge-welding roll to form a pipe. In order to form into a tubular shape with the above forming roll, the forming stand is made into two stands, and the first
A forge welded steel pipe forming method characterized in that the stand is a vertical stand, the second stand is a horizontal stand, and a seam guide is attached to a large roll of the second stand.