JP3228169B2 - Plug for piercing and rolling of seamless metal pipe and method of manufacturing seamless metal pipe using this plug - Google Patents
Plug for piercing and rolling of seamless metal pipe and method of manufacturing seamless metal pipe using this plugInfo
- Publication number
- JP3228169B2 JP3228169B2 JP05314997A JP5314997A JP3228169B2 JP 3228169 B2 JP3228169 B2 JP 3228169B2 JP 05314997 A JP05314997 A JP 05314997A JP 5314997 A JP5314997 A JP 5314997A JP 3228169 B2 JP3228169 B2 JP 3228169B2
- Authority
- JP
- Japan
- Prior art keywords
- plug
- rolling
- piercing
- thickness
- scale film
- 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 - Fee Related
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Landscapes
- Reduction Rolling/Reduction Stand/Operation Of Reduction Machine (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、継目無金属管の穿
孔圧延用プラグと、このプラグを用いた継目無金属管の
製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug for piercing and rolling a seamless metal pipe and a method for manufacturing a seamless metal pipe using the plug.
【０００２】[0002]
【従来の技術】継目無金属管の製造方法として広く採用
されているいわゆるマンネスマン製管法は、周知のよう
に、所定温度に加熱された中実の丸ビレットを素材と
し、この丸ビレットを穿孔圧延機（以下、ピアサーとい
う）に送給してその軸心部に孔を明けてホローシェルに
成形する。次いで、得られたホローシェルをそのままあ
るいは必要に応じて前記ピアサーと同一構成のエロンゲ
ーターもしくはサイザーに通して拡径もしくは縮径する
ことにより定径化せしめた後、プラグミル、マンドレル
ミルなどの後続する延伸圧延機に送給して延伸圧延す
る。さらに、上記延伸圧延後の管をストレッチレデュー
サ、リーラ、サイザーなどの仕上げ圧延機に通して磨
管、形状修正およびサイジングを行って所定寸法の製品
管に成形する方法である。2. Description of the Related Art As is well known, a so-called Mannesmann pipe manufacturing method widely used as a method for manufacturing a seamless metal pipe uses a solid round billet heated to a predetermined temperature as a raw material and drills the round billet. It is fed to a rolling mill (hereinafter, referred to as a piercer), and a hole is formed in the axial center thereof to form a hollow shell. Next, the obtained hollow shell is passed through an elongator or a sizer having the same configuration as the piercer as it is or as necessary, and then reduced in diameter by expanding or reducing the diameter, and then subjected to subsequent stretching such as a plug mill or a mandrel mill. It is fed to a rolling mill and stretched and rolled. Further, there is a method in which the pipe after the above elongation rolling is passed through a finish rolling mill such as a stretch reducer, a reeler, a sizer, etc. to perform polishing, shape correction and sizing to form a product pipe of a predetermined size.
【０００３】図３は、上記の如きマンネスマン製管法の
実施に用いる穿孔圧延機の一例を示す斜視図である。図
示例のピアサーは、被穿孔材料である中実の丸ビレット
４の送り線となるパスラインＸ−Ｘを挟んで互いに逆方
向に傾斜させて対向配置されたバレル型の一対の主ロー
ル１、１を備えている。また、主ロール１、１と位相を
９０°位相させて前記パスラインＸ−Ｘを挟んで対向配
置された一対のディスクロール２、２を備えている。さ
らに、主ロール１、１間のパスラインＸ−Ｘ上には、芯
金５で支持された穿孔工具としてのプラグ３を備えてい
る。FIG. 3 is a perspective view showing an example of a piercing mill used for carrying out the Mannesmann pipe manufacturing method as described above. The illustrated piercer has a pair of barrel-type main rolls 1, which are arranged to face each other with a slant in opposite directions with respect to a pass line XX serving as a feed line of a solid round billet 4 as a material to be perforated. 1 is provided. In addition, a pair of disk rolls 2 and 2 are provided so as to be 90 ° out of phase with the main rolls 1 and 1 with the pass line XX interposed therebetween. Further, on a pass line XX between the main rolls 1 and 1, a plug 3 as a drilling tool supported by a cored bar 5 is provided.
【０００４】上記のように構成されたピアサーにおいて
は、主ロール１、１がパスラインＸ−Ｘに対して傾斜角
βを付与されて同一方向に回転駆動される。このため、
パスラインＸ−Ｘに沿って白抜き矢符方向に送給された
丸ビレット４は、主ロール１、１間に噛み込んだ後は螺
進行移動し、プラグ３によりその軸心部に孔を明けられ
てホローシェルとなる。この間、ディスクロール２、２
は、圧延中の丸ビレット４の案内部材の役目をすると同
時に、プラグ３により穿孔されたホローシェルの主ロー
ル１、１の対向方向と９０°移送した方向への膨らみを
抑制して外径形状を整える役目をなしている。また、デ
ィスクロール２、２は、穿孔されたホローシェルとの摺
動を軽減して焼付きが発生しないように丸ビレット４の
送り出し方向と同方向に回転駆動される。In the piercer configured as described above, the main rolls 1 and 1 are provided with an inclination angle β with respect to the pass line XX and are driven to rotate in the same direction. For this reason,
The round billet 4 fed in the direction of the white arrow along the pass line XX is screwed and moved after being caught between the main rolls 1 and 1, and a hole is formed in the axial center portion by the plug 3. It becomes a hollow shell after dawn. During this time, disk rolls 2, 2
Serves as a guide member for the round billet 4 during rolling, and at the same time, suppresses swelling of the hollow shell in the direction of 90 ° transfer with respect to the opposing direction of the main rolls 1 and 1 pierced by the plug 3 to reduce the outer diameter shape. It plays the role of trimming. The disc rolls 2 and 2 are driven to rotate in the same direction as the direction in which the round billet 4 is fed out so that sliding with the perforated hollow shell is reduced and seizure does not occur.
【０００５】一方、プラグ３は、耐焼付性を付与するた
め、通常、その使用前に酸化雰囲気中で熱処理を施して
その表面に酸化鉄を主成分とするスケール皮膜が形成さ
せてある。また、穿孔圧延に供された後のプラグ３は、
温度が高温に達し、そのまま継続使用すると寿命が極め
て短くなるので、複数個のプラグを冷却しながら順番に
繰り返し循環使用される。On the other hand, the plug 3 is usually subjected to a heat treatment in an oxidizing atmosphere before use to form a scale film mainly composed of iron oxide on its surface in order to impart seizure resistance. Further, the plug 3 after being subjected to the piercing and rolling,
Since the temperature reaches a high temperature and the life is extremely shortened if the plug is used continuously, the plugs are repeatedly circulated and used while cooling a plurality of plugs.
【０００６】ところで、以上の如き穿孔圧延方法におい
て、プラグ３は穿孔圧延中に材料から受ける熱負荷によ
ってしばしばその先端部が溶損し、新たなプラグとの交
換を余儀なくされるため、製造コストを引き上げる最も
大きな原因の一つとなっている。また、先端部が熱溶損
したプラグを使用して穿孔圧延すると、得られたホロー
シェルの内面に疵が発生し、製品品質上の大きな問題と
なる。[0006] In the piercing and rolling method as described above, the tip of the plug 3 is often melted by the heat load received from the material during the piercing and rolling, and the plug 3 must be replaced with a new plug. It is one of the biggest causes. In addition, when piercing and rolling is performed using a plug whose tip is thermally damaged, flaws occur on the inner surface of the obtained hollow shell, which is a major problem in product quality.
【０００７】さらに、近年における継目無金属管需要の
大部分を占める油井管やラインパイプは、劣悪な環境の
油井戸やガス井戸の開発が増すのに伴ってステンレス鋼
やＮｉ基合金などの高耐食性材料からなる製品が求めら
れている。ところが、これらの高耐食性材料は炭素鋼に
比べて変形抵抗が大きく、炭素鋼よりも高温に加熱され
て穿孔圧延機に供給される。このため、これらの材料を
穿孔圧延するとプラグ３にはより大きな圧力および熱負
荷がかかり、そのプラグ寿命が１０パスにも満たない場
合が多く、製造コストに占めるプラグ価格の割合がます
ます多くなっている。Furthermore, oil well pipes and line pipes, which account for a large part of the demand for seamless metal pipes in recent years, have been developed with the development of oil wells and gas wells in a poor environment. There is a need for products made of corrosion resistant materials. However, these high corrosion resistant materials have higher deformation resistance than carbon steel, and are heated to a higher temperature than carbon steel before being supplied to a piercing mill. For this reason, when these materials are pierced and rolled, the plug 3 is subjected to greater pressure and heat load, and the life of the plug is often less than 10 passes, and the ratio of the plug price to the manufacturing cost is increasing more and more. ing.
【０００８】このため、上記のような変形抵抗の大きい
材料を穿孔圧延する場合には、一般的なＣｒ−Ｎｉ系の
低合金鋼製のプラグのほか、高温下におけるプラグの変
形抵抗を増加させるとともに、その表面に地金との密着
性に優れた均一厚さのスケール皮膜を形成させることを
目的として、Ｗ、Ｍｏ、Ｎｂなどの元素を微量添加した
低合金鋼製のプラグが用いられている。Therefore, when piercing and rolling a material having a large deformation resistance as described above, the deformation resistance of the plug at high temperatures is increased in addition to the general Cr-Ni-based low alloy steel plug. At the same time, low-alloy steel plugs with a small amount of elements such as W, Mo, and Nb are used for the purpose of forming a scale film of uniform thickness with excellent adhesion to the base metal on the surface thereof. I have.
【０００９】また、プラグの全表面に厚さ２５０〜１０
００μｍの均一なスケール皮膜を形成させることによ
り、プラグの使用寿命を高めることも行われている（特
開平７−６０３１４号公報）。これは、プラグ寿命の向
上に対して非常に有効な手段であり、熱処理雰囲気の水
蒸気圧を高めること、もしくは熱処理時間を長くするこ
とにより簡単に行うことができる。しかし、スケール皮
膜の厚いプラグを用いた場合、仕上げ圧延後の製品管Ｐ
の内表面に米粒状の被れ疵Ｋが多発し、その手入れ除去
工数が多大になるという問題があった。Further, the thickness of the plug is 250 to 10
The service life of the plug is also increased by forming a uniform scale film of 00 μm (Japanese Patent Application Laid-Open No. 7-60314). This is a very effective means for improving the life of the plug, and can be easily performed by increasing the water vapor pressure of the heat treatment atmosphere or lengthening the heat treatment time. However, when a plug with a thick scale film is used, the product pipe P after finish rolling is used.
There is a problem that rice grain-like flaws K frequently occur on the inner surface of the steel sheet, and the number of steps for maintenance and removal thereof becomes large.
【００１０】すなわち、上記の被れ疵Ｋは、図４に示す
ように、製品管Ｐの全内表面にわたって発生し、その深
さは高々数百μｍで比較的浅いもののそのまま出荷する
と、製品管に負荷がかかった場合、破壊にいたる亀裂進
展の起点になるので、手入れ除去する必要がある。この
ため、上記被れ疵Ｋの発生を防ぐ方法の開発が望まれて
いた。That is, as shown in FIG. 4, the above-mentioned flaw K occurs over the entire inner surface of the product pipe P, and its depth is at most several hundred μm, which is relatively shallow. When a load is applied, it becomes a starting point of crack growth leading to fracture, so it is necessary to remove it by care. Therefore, development of a method for preventing the generation of the above-mentioned flaw K has been desired.
【００１１】[0011]
【発明が解決しようとする課題】本発明は、上記の実状
に鑑みてなされたもので、その課題は上記被れ疵の発生
を抑制することができるとともに、プラグ寿命の低下を
きたすことのない継目無金属管の穿孔圧延用プラグと、
このプラグを用いた継目無金属管の製造方法を提供する
ことにある。SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to suppress the occurrence of the above-mentioned flaws and not to shorten the life of the plug. A plug for piercing and rolling a seamless metal pipe,
An object of the present invention is to provide a method for manufacturing a seamless metal pipe using the plug.
【００１２】[0012]
【課題を解決するための手段】本発明の要旨は、下記
（１）の継目無金属管の穿孔圧延用プラグ、および下記
（２）の継目無金属管の製造方法にある。The gist of the present invention resides in the following (1) a plug for piercing and rolling a seamless metal pipe and a method (2) for producing a seamless metal pipe.
【００１３】（１）表面にスケール皮膜を有する砲弾形
状をした継目無金属管の穿孔圧延用プラグであって、リ
ーリング部のスケール皮膜厚さが圧延部のスケール皮膜
厚さよりも薄いことを特徴とする継目無金属管の穿孔圧
延用プラグ。(1) A plug for piercing and rolling a shell-shaped seamless metal tube having a scale film on its surface, wherein a scale film thickness at a reeling portion is smaller than a scale film thickness at a rolled portion. For piercing and rolling seamless metal pipes.
【００１４】（２）傾斜ロール式の穿孔圧延機に対して
請求項１に記載の穿孔圧延用プラグをセットし、所定の
温度に加熱された中実丸ビッレトをホローシェルに穿孔
圧延することを特徴とする継目無金属管の製造方法。(2) The piercing and rolling plug according to claim 1 is set in an inclined roll type piercing and rolling mill, and a solid round billet heated to a predetermined temperature is pierced and rolled into a hollow shell. A method of manufacturing a seamless metal pipe.
【００１５】本発明者らは、数多くの製造実験と詳細な
調査を行った結果、次のことを知見し、本発明をなすに
いたった。The present inventors have conducted a number of production experiments and detailed investigations, and as a result, have found the following, and have accomplished the present invention.
【００１６】先ず最初に、本発明者らは、上記の被れ疵
の発生機構と、その全表面に厚さの厚い均一なスケール
皮膜を形成させたプラグを用いた場合に上記の被れ疵が
多発する原因の究明に努めた。その結果、次のことが明
らかになった。First, the inventors of the present invention considered the mechanism of generation of the above-mentioned flaw and the above-mentioned flaw when using a plug having a uniform and thick scale film formed on the entire surface thereof. Tried to find the cause of the frequent occurrence. As a result, the following became clear.
【００１７】すなわち、上記の被れ疵Ｋは、図５に示す
ように、ピアサーによる穿孔圧延時にホローシェルＨの
内表面に生じた凹凸が次工程のエロンゲーター（図５中
の（ａ））もしくはマンドレルミルやプラグミル（図５
中の（ｂ））による延伸圧延時に内面規制工具であるプ
ラグ３０やマンドレルバーＭ（プラグミルではプラグ）
によって薄く押し潰されて被れ疵Ｋになること。また、
その凹凸の程度、換言すればホローシェルＨの内表面粗
さが粗ければ粗いほど、被れ疵Ｋが多く発生することが
わかった。That is, as shown in FIG. 5, the above-mentioned flaw K is caused by unevenness generated on the inner surface of the hollow shell H at the time of piercing and rolling by a piercer or an elongator ((a) in FIG. 5) in the next step. Mandrel mill and plug mill (Fig. 5
The plug 30 and the mandrel bar M (a plug in a plug mill) which are inner surface regulating tools at the time of elongation rolling according to (b)) in FIG.
Is crushed thinly and becomes a flaw K. Also,
It was found that as the degree of the unevenness, in other words, the rougher the inner surface roughness of the hollow shell H, the more the flaw K was generated.
【００１８】そこで、ホローシェルＨの内表面粗さに影
響を及ぼす因子を見いだすべく、種々の調査を重ねたと
ころ、その内表面粗さは穿孔圧延に供した後のプラグの
リーリング部の表面粗さとほぼ一致すること。また、そ
の内表面粗さの程度は、プラグのリーリング部表面に形
成させたスケール皮膜の厚さが厚ければ厚いほど粗くな
ることが判明した。このことは、図６および図７に示す
調査結果から明らである。Therefore, various investigations were conducted to find factors affecting the inner surface roughness of the hollow shell H. The inner surface roughness was found to be the surface roughness of the reeling portion of the plug after piercing and rolling. It almost matches. In addition, it was found that the degree of the inner surface roughness increased as the thickness of the scale film formed on the surface of the reeling portion of the plug increased. This is clear from the survey results shown in FIGS.
【００１９】図６は、穿孔圧延に供した後のプラグのリ
ーリング部の表面粗さと、この時得られたホローシェル
Ｈの内表面粗さ（いずれも、ＪＩＳ−０６０１に定義さ
れる最大高さＲｙ）との関係を示す図である。FIG. 6 shows the surface roughness of the reeling portion of the plug after piercing and rolling, and the inner surface roughness of the hollow shell H obtained at this time (both are the maximum heights defined in JIS-0601). Ry).
【００２０】また、図７は、穿孔圧延に供する前のプラ
グ全表面に均一厚さで形成させたスケール皮膜の厚さ
（μｍ）と、これらのプラグを用いて穿孔圧延して得ら
れたホローシェルＨの内面粗さ（上記の最大高さＲｙ）
およびプラグ寿命（パス回数）との関係を示す図であ
る。FIG. 7 shows the thickness (μm) of the scale film formed to a uniform thickness on the entire surface of the plug before being subjected to piercing and rolling, and the hollow shell obtained by piercing and rolling using these plugs. H inner surface roughness (above maximum height Ry)
FIG. 7 is a diagram showing a relationship between the plug life and the plug life (the number of passes).
【００２１】図６から、得られたホローシェルＨの内表
面粗さは、その時に用いた使用後のプラグのリーリング
部の表面粗さとほぼ同じであることがわかる。また、図
７から、得られたホローシェルＨの内表面粗さは、プラ
グの表面に形成させたスケール皮膜の厚さが薄ければ薄
いほど小さくなるものの、そのプラグ寿命が短くなるこ
とがわかる。FIG. 6 shows that the inner surface roughness of the obtained hollow shell H is almost the same as the surface roughness of the reeling portion of the used plug used at that time. FIG. 7 shows that the inner surface roughness of the obtained hollow shell H becomes smaller as the thickness of the scale film formed on the surface of the plug becomes smaller, but the plug life becomes shorter.
【００２２】なお、上記両図中におけるホローシェルの
内表面粗さおよびプラグのリーリング部表面粗さの最大
高さ（Ｒｙ）の値は、いずれも４５°ピッチで測定した
円周方向８ヶ所の最大高さ（Ｒｙ）の平均値である。ま
た、スケール皮膜厚さは、酸化雰囲気中での加熱温度と
保持時間を変えることで種々変化させた。In both figures, the values of the inner surface roughness of the hollow shell and the maximum height (Ry) of the surface roughness of the reeling portion of the plug were measured at eight positions in the circumferential direction at 45 ° pitch. This is the average value of the maximum height (Ry). Further, the thickness of the scale film was variously changed by changing the heating temperature and the holding time in the oxidizing atmosphere.
【００２３】ここで、ホローシェルＨの内表面粗さと、
この時用いた使用後のプラグのリーリング部の表面粗さ
とがほぼ同じなるのは、次の理由によると推定される。Here, the inner surface roughness of the hollow shell H is
The reason why the surface roughness of the reeling portion of the used plug used at this time is substantially the same is presumed to be as follows.
【００２４】すなわち、プラグの表面に形成されたスケ
ール皮膜のうち、リーリング部の上流側に位置する圧延
部表面に形成されたスケール皮膜は、穿孔圧延中に大き
な熱負荷を受け、温度上昇して溶融するので、その表面
粗さが小さくなる。これに対し、リーリング部表面に形
成されたスケール皮膜は、圧延部に比べて温度上昇が小
さく溶融しない。この結果、リーリング部表面に形成さ
れたスケール皮膜の表面粗さがそのままホローシェルの
内表面にプリントされるようになるためと推定される。That is, among the scale films formed on the surface of the plug, the scale film formed on the surface of the rolled portion located on the upstream side of the reeling portion receives a large heat load during the piercing rolling, and the temperature rises. , And the surface roughness is reduced. On the other hand, the scale film formed on the surface of the reeling portion has a smaller temperature rise than the rolled portion and does not melt. As a result, it is estimated that the surface roughness of the scale film formed on the surface of the reeling portion is printed on the inner surface of the hollow shell as it is.
【００２５】また、プラグの表面に形成させたスケール
皮膜の厚さが薄ければ薄いほどホローシェルの内表面粗
さが小さくなる、換言すればスケール皮膜の厚さが厚け
れば厚いほどホローシェルの内表面粗さが粗くなるの
は、厚さの厚いスケール皮膜ほど、その表面粗さの最大
高さ（Ｒｙ）が大ききためであると推定される。Also, the smaller the thickness of the scale film formed on the surface of the plug, the smaller the inner surface roughness of the hollow shell. In other words, the thicker the scale film, the more the inside of the hollow shell. It is estimated that the reason why the surface roughness is increased is that the larger the thickness of the scale film, the larger the maximum height (Ry) of the surface roughness.
【００２６】また更に、プラグの表面に形成させたスケ
ール皮膜の厚さが薄ければ薄いほどプラグ寿命が短くな
る、換言すればスケール皮膜の厚さが厚ければ厚いほど
プラグ寿命が長くなるのは、厚さの厚いスケール皮膜ほ
ど、断熱性と潤滑性が高く、プラグ本体自体の熱変形と
摩耗損傷が抑制されるためであると推定される。Furthermore, the plug life becomes shorter as the thickness of the scale film formed on the surface of the plug becomes thinner. In other words, the plug life becomes longer as the thickness of the scale film becomes thicker. It is presumed that the larger the thickness of the scale film, the higher the heat insulation and lubricity, and the more the thermal deformation and wear damage of the plug body itself are suppressed.
【００２７】以上の結果、プラグ寿命を低下させること
なく、しかも延伸圧延後の製品管の内表面に生じる被れ
疵の発生原因であるホローシェルＨの内表面粗さを小さ
くするには、プラグ全表面に均一厚さのスケール皮膜を
形成させるのではなく、リーリング部に形成させるスケ
ール皮膜厚さを圧延部のそれよりも薄くすればよいこと
を知見した。As a result, in order to reduce the inner surface roughness of the hollow shell H, which is a cause of the generation of flaws on the inner surface of the product pipe after elongation rolling, without reducing the life of the plug, it is necessary to use the entire plug. Instead of forming a scale film with a uniform thickness on the surface, the inventors found that the scale film formed on the reeling portion should be thinner than that on the rolled portion.
【００２８】[0028]
【発明の実施の形態】以下、添付図面を参照して、本発
明のプラグと、このプラグを用いた継目無金属管の製造
方法について詳細に説明する。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A plug according to the present invention and a method for manufacturing a seamless metal pipe using the plug will be described below in detail with reference to the accompanying drawings.
【００２９】図１は、本発明にかかわるプラグ３の一例
を示す縦断面で、全体形状として砲弾形状に成形されて
おり、その軸長方向に先端部の圧延部３ａと、中間部の
リーリング部３ｂと、終端部の逃げ部３ｃとで構成され
ている。FIG. 1 is a longitudinal section showing an example of a plug 3 according to the present invention, which is formed in a shell shape as a whole, and has a rolled portion 3a at the tip and a reeling portion at the middle in the axial direction. It comprises a part 3b and a relief part 3c at the end.
【００３０】そして、図示しない芯金に連結され後端面
３ｄを除く表面には、スケール皮膜Ｓが形成おり、リー
リング部３ｂのスケール皮膜Ｓの厚さＴ2 が圧延部３ａ
のスケール皮膜Ｓの厚さＴ1 よりも薄くされている。[0030] On the surface except for the rear end face 3d is connected to the core, not shown, the scale film S are formed, the scale film S of the second thickness T 2 is rolled portion 3a of the reeling portion 3b
It is thinner than the thickness T 1 of the scale membrane S.
【００３１】ここで、リーリング部３ｂのスケール皮膜
Ｓの厚さＴ2 は、圧延部３ａのスケール皮膜Ｓの厚さＴ
1 よりも薄ければよく、その厚さ比（Ｔ2 ／Ｔ1 ）に特
別な制約はない。これは、前述の図６および図７に示す
調査結果からもわかるように、ホローシェルＨの内面粗
さは、リーリング部３ｂの表面粗さによって異なり、し
かもリーリング部３ｂの表面に形成させたスケール皮膜
Ｓの厚さＴ2 が薄ければ薄いほど小さくなるためであ
る。Here, the thickness T 2 of the scale film S of the reeling portion 3b is equal to the thickness T of the scale film S of the rolling portion 3a.
It suffices if it is thinner than 1, and there is no particular restriction on the thickness ratio (T 2 / T 1 ). As can be seen from the investigation results shown in FIGS. 6 and 7 described above, the inner surface roughness of the hollow shell H differs depending on the surface roughness of the reeling portion 3b and is formed on the surface of the reeling portion 3b. This is because the smaller the thickness T 2 of the scale film S, the smaller the thickness.
【００３２】また、上記の厚さＴ1 とＴ2 の具体値に特
別な制約はなく、厚さＴ1 については所望のプラグ寿命
が得られる厚さに、また厚さＴ2 については所望のホロ
ーシェルの内表面粗さが得られる厚さに、それぞれ定め
ればよい。There is no particular limitation on the specific values of the thicknesses T 1 and T 2. The thickness T 1 is a thickness that can provide a desired plug life, and the thickness T 2 is a desired thickness. The thickness may be set to a thickness at which the inner surface roughness of the hollow shell is obtained.
【００３３】リーリング部３ｂのスケール皮膜Ｓの厚さ
Ｔ2 を圧延部３ａのスケール皮膜Ｓの厚さＴ1 よりも薄
くする方法は、どのような方法であってもよいが、例え
ばプラグ３の全表面に厚さＴ1 のスケール皮膜Ｓを形成
させた後、リーリング部３ｂと逃げ部３ｃ部のスケール
皮膜Ｓの表層部分を砥石などで研磨除去するなどして厚
さＴ2 に調整すればよい。The thickness T 2 of the scale film S of the reeling portion 3 b may be made smaller than the thickness T 1 of the scale film S of the rolling portion 3 a by any method. All after forming a scale film S having a thickness of T 1 to the surface, adjusting the surface layer portion of the scale film S of the reeling portion 3b and the escape portion 3c portion the second thickness T 2 by, for example, polished and removed like grindstone do it.
【００３４】また、上記の砥石などによる研磨除去に代
えて、旋盤による切削除去加工、圧延部３ａの表面を保
護テープなどでマスキングした後にリーリング部３ｂに
ショットブラスト処理を施すなどして厚さ調整するよう
にしてもよい。In place of the above-described polishing and removal using a grindstone or the like, cutting and removing by a lathe, masking the surface of the rolled portion 3a with a protective tape or the like, and then performing shot blasting on the reeling portion 3b to obtain a thickness It may be adjusted.
【００３５】ただし、厚さ調整後のスケール皮膜Ｓの表
面粗さは、ショットブラスト処理や砥石などで研磨除去
して厚さを調整した場合、旋盤による切削除去加工によ
って調整した場合に比べて粗くなる傾向がある。従っ
て、その厚さ調整は旋盤による切削除去加工によって行
うのが最も好ましい。However, the surface roughness of the scale film S after the thickness adjustment is rougher in the case where the thickness is adjusted by removing the surface by shot blasting or polishing with a grindstone or the like, as compared with the case where the thickness is adjusted by cutting and removing with a lathe. Tend to be. Therefore, it is most preferable to adjust the thickness by cutting and removing with a lathe.
【００３６】上記のように構成された本発明のプラグ３
は、前述の図３に示すようなピアサーにセットして使用
される。この場合、プラグ３のリーリング部３ｂの表面
には、厚さがＴ2 で、圧延部３ａの表面に形成させた厚
さＴ1 よりも薄いスケール皮膜Ｓが形成してあるため
に、プラグ寿命の低下をきすことなく、内表面粗さ（最
大高さＲｙ）の小さい、すなわち凹凸の程度が抑制され
たホローシェルＨが得らる。この結果、このホローシェ
ルＨをエロンゲーターもしくはマンドレルミルやプラグ
ミルなどで延伸圧延しても、その内表面の凹凸が薄く押
し潰されて米粒状の被れ疵Ｋ（図５参照）になる部分が
少ないので、被れ疵Ｋの少ない製品管が得られ、その手
入れ除去工数の低減が図れる。The plug 3 of the present invention configured as described above
Is used by being set in the piercer as shown in FIG. In this case, since the surface of the reeling portion 3b of the plug 3, which a thickness of T 2, a thin scale membrane S than the thickness T 1 which is formed on the surface of the rolling portion 3a is formed, the plug A hollow shell H having a small inner surface roughness (maximum height Ry), that is, a reduced degree of unevenness, can be obtained without shortening the life. As a result, even if this hollow shell H is stretched and rolled by an elongator, a mandrel mill, a plug mill, or the like, there are few portions where the irregularities on the inner surface are thinly crushed and become rice grain-like flaws K (see FIG. 5). As a result, a product tube having less flaws K can be obtained, and the number of steps for maintenance and removal can be reduced.
【００３７】[0037]
【実施例】表１に示す化学成分を有する２鋼種からな
り、鋳造後に旋盤を用いて図２に示す形状寸法に切削成
形した後、さらにその表面に表２に示す条件でショット
ブラスト処理を施した２種類のプラグを５個づつ準備し
た。EXAMPLE It consists of two steel types having the chemical components shown in Table 1, and after being cast, formed into a shape and dimensions as shown in FIG. 2 using a lathe, and further subjected to shot blasting on the surface under the conditions shown in Table 2. Five of the two types of plugs thus prepared were prepared.
【００３８】[0038]
【表１】 [Table 1]
【００３９】[0039]
【表２】 [Table 2]
【００４０】次いで、上記２種類のプラグ１０個を水蒸
気濃度が１４体積％以上の酸化性雰囲気の加熱炉に挿入
し、１０５０℃に６時間均熱保持した後、５０℃／ｈｒ
の冷却速度で８００℃まで徐冷する熱処理を施し、その
全表面に、鋼種Ａのプラグについては厚さ３００μｍ、
鋼種Ｂのプラグについては厚さ２５０μｍのＦｅＯを主
体とするスケール皮膜を形成させた。Next, 10 plugs of the above two types were inserted into a heating furnace in an oxidizing atmosphere having a water vapor concentration of 14% by volume or more, kept at 1050 ° C. for 6 hours, and then heated at 50 ° C./hr.
Heat treatment to gradually cool down to 800 ° C. at a cooling rate of 300 μm for a plug of steel type A,
Regarding the plug of steel type B, a 250 μm-thick scale film mainly composed of FeO was formed.
【００４１】また、スケール皮膜を形成させた各鋼種の
プラグのうち、それぞれ４個については、そのリーリン
グ部のスケール皮膜の厚さを、表３に示す４種類の厚さ
に調整した。この時、厚さ調整方法としては、旋盤によ
る切削除去加工法と、圧延部の表面を保護テープでマス
キングした後、リーリング部にショットブラスト処理を
施す方法とを用いた。なお、ショットブラスト処理は、
投射時間以外は上記表２に示す条件と同じにした。For each of the four plugs of each steel type having the scale film formed thereon, the thickness of the scale film at the reeling portion was adjusted to four types shown in Table 3. At this time, as a thickness adjusting method, a cutting and removing method using a lathe and a method of performing a shot blast treatment on a reeling portion after masking the surface of a rolled portion with a protective tape were used. In addition, shot blast processing
Except for the projection time, the conditions were the same as those shown in Table 2 above.
【００４２】[0042]
【表３】 [Table 3]
【００４３】[0043]
【表４】 [Table 4]
【００４４】[0044]
【表５】 [Table 5]
【００４５】これら１０種類のプラグを、図３に示した
と同様構成のピアサーにセットし、ＳＵＳ３０４製の中
実丸ビッレトの穿孔圧延に供した。この時、ピアサーに
よる穿孔圧延条件と、これに引き続く延伸圧延と仕上げ
圧延スケジュールは、表４および表５に示す通りとし
た。These ten types of plugs were set in a piercer having the same configuration as that shown in FIG. 3 and subjected to piercing and rolling of a solid round billet made of SUS304. At this time, the piercing and rolling conditions by the piercer and the subsequent elongation rolling and finish rolling schedule were as shown in Tables 4 and 5.
【００４６】そして、ピアサーでは、各プラグの先端部
が溶損するまでに穿孔圧延することができたビッレト本
数（パス回数）を調べ、そのプラグ寿命を調査した。ま
た、レデュサーによる仕上げ圧延後の製品管の軸長方向
の中央部から１ｍの試験片を切り出し採取し、その内表
面を目視観察し、米粒状の被れ疵Ｋの発生個数を調べ
た。これらの結果を、上記の表３に併記して示した。In the piercer, the number of pits (the number of passes) that could be pierced and rolled before the tip of each plug was melted was examined, and the life of the plug was examined. In addition, a test piece of 1 m was cut out from the central part in the axial direction of the product tube after finish rolling by a reducer and sampled, and the inner surface thereof was visually observed to determine the number of rice grain-like flaws K generated. The results are shown in Table 3 above.
【００４７】表３に示す結果から明らかなように、圧延
部とリーリング部のスケール皮膜厚さが同じである従来
のプラグを用いた場合、仕上げ圧延後の製品管の内表面
に、鋼種Ａのプラグ（試番１）では２４個、鋼種Ｂのプ
ラグ（試番６）では１１個、という多くの被れ疵が発生
した。As is evident from the results shown in Table 3, when a conventional plug having the same scale film thickness in the rolled portion and the reeling portion was used, the steel type A was formed on the inner surface of the product pipe after the finish rolling. A large number of flaws were generated in 24 plugs (No. 1) and 11 plugs in the steel type B plug (No. 6).
【００４８】これに対し、本発明のプラグを用いた場
合、鋼種Ａのプラグ（試番２〜５）では最大で約半分の
１３個、鋼種Ｂのプラグ（試番７〜１０）では最大で７
個、の被れ疵が発生していたにすぎなかった。また、そ
のプラグ寿命は、いずれの鋼種のプラグも従来のプラグ
と同じであった。On the other hand, when the plug of the present invention is used, the plug of steel type A (test numbers 2 to 5) has a maximum of about thirteen, and the plug of steel type B (test numbers 7 to 10) has a maximum of 13. 7
There was only a flaw of the individual. In addition, the plug life was the same for all steel plugs as for conventional plugs.
【００４９】[0049]
【発明の効果】本発明によれば、プラグ自体の寿命を低
下させることなく、製品管の内表面に発生する被れ疵の
発生個数を大幅に少なくすることができる。その結果、
その手入れ除去工数の低減が図れ、製品管の製造コスト
上昇を防ぐことができるのみならず、高品質な製品管を
提供することができる。According to the present invention, the number of flaws generated on the inner surface of the product tube can be greatly reduced without reducing the life of the plug itself. as a result,
The number of maintenance and removal steps can be reduced, and not only can the production cost of the product tube be prevented from increasing, but also a high-quality product tube can be provided.
【図１】本発明にかかわるプラグの一例を示す縦断面図
である。FIG. 1 is a longitudinal sectional view showing an example of a plug according to the present invention.
【図２】実施例で用いたプラグの形状寸法を示す図であ
る。FIG. 2 is a view showing the shape and dimensions of a plug used in an example.
【図３】ピアサーの構成例を示す斜視図である。FIG. 3 is a perspective view showing a configuration example of a piercer.
【図４】製品管の内表面に発生する被れ疵の発生態様
と、その被れ疵の模式的断面を示す図である。FIG. 4 is a view showing a mode of occurrence of flaws generated on an inner surface of a product pipe, and a schematic cross section of the flaws.
【図５】製品管の内表面に発生する被れ疵の発生機構を
説明するための図である。FIG. 5 is a view for explaining a mechanism of generating a flaw generated on an inner surface of a product pipe.
【図６】穿孔圧延に供した後のプラグのリーリング部の
表面粗さと、この時得られたホローシェルの内表面粗さ
との関係を示す図である。FIG. 6 is a diagram showing the relationship between the surface roughness of the reeling portion of the plug after being subjected to piercing and rolling and the inner surface roughness of the hollow shell obtained at this time.
【図７】プラグ表面に形成させたスケール皮膜の厚さ
と、この時に得られたホローシェルの内面粗さ、および
プラグ寿命との関係を示す図である。FIG. 7 is a view showing the relationship between the thickness of a scale film formed on the plug surface, the inner surface roughness of the hollow shell obtained at this time, and the life of the plug.
１ ：主ロール、 ２ ：ディスクロール、 ３ ：プラグ、 ３ａ：圧延部、 ３ｂ：リーリング部、 ３ｃ：逃げ部、 ３ｄ：後端面、 ４ ：丸ビッレト ５ ：芯金、 ３０：プラグ、 Ｋ ：被れ疵、 Ｈ ：ホローシェル、 Ｐ ：製品管、 Ｍ ：マンドレルバー、 Ｓ ：スケール皮膜。 1: Main roll, 2: Disc roll, 3: Plug, 3a: Rolling section, 3b: Reeling section, 3c: Relief section, 3d: Rear end face, 4: Round billet 5: Core, 30: Plug, K: Scratch flaw, H: hollow shell, P: product tube, M: mandrel bar, S: scale film.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平９−276909（ＪＰ，Ａ) 特開 平４−74848（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B21B 25/00 ────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-9-276909 (JP, A) JP-A-4-74848 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) B21B 25/00
Claims (2)
た継目無金属管の穿孔圧延用プラグであって、リーリン
グ部のスケール皮膜厚さが圧延部のスケール皮膜厚さよ
りも薄いことを特徴とする継目無金属管の穿孔圧延用プ
ラグ。1. A piercing and rolling plug for a shell-shaped seamless metal tube having a scale film on its surface, wherein a scale film thickness of a reeling portion is smaller than a scale film thickness of a rolled portion. For piercing and rolling seamless metal pipes.
１に記載の穿孔圧延用プラグをセットし、所定の温度に
加熱された中実丸ビッレトをホローシェルに穿孔圧延す
ることを特徴とする継目無金属管の製造方法。2. The piercing and rolling plug according to claim 1 is set in an inclined roll type piercing and rolling mill, and a solid round billet heated to a predetermined temperature is pierced and rolled into a hollow shell. Of manufacturing seamless metal pipes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05314997A JP3228169B2 (en) | 1997-03-07 | 1997-03-07 | Plug for piercing and rolling of seamless metal pipe and method of manufacturing seamless metal pipe using this plug |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP05314997A JP3228169B2 (en) | 1997-03-07 | 1997-03-07 | Plug for piercing and rolling of seamless metal pipe and method of manufacturing seamless metal pipe using this plug |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10249412A JPH10249412A (en) | 1998-09-22 |
| JP3228169B2 true JP3228169B2 (en) | 2001-11-12 |
Family
ID=12934785
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP05314997A Expired - Fee Related JP3228169B2 (en) | 1997-03-07 | 1997-03-07 | Plug for piercing and rolling of seamless metal pipe and method of manufacturing seamless metal pipe using this plug |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3228169B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103240274A (en) * | 2013-05-10 | 2013-08-14 | 攀钢集团成都钢钒有限公司 | Piercing plug device of piercer, piercer and production method of seamless steel tubes |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1929933B (en) * | 2004-03-11 | 2010-10-13 | 住友金属工业株式会社 | Seamless tube piercing/rolling plug, seamless tube producing apparatus, and seamless tube producing method therewith |
| JP5131702B2 (en) * | 2007-02-05 | 2013-01-30 | 新日鐵住金株式会社 | Manufacturing method of plug used for piercing and rolling of metal material, manufacturing method of metal tube, and plug used for piercing and rolling of metal material |
| WO2009057471A1 (en) * | 2007-11-01 | 2009-05-07 | Sumitomo Metal Industries, Ltd. | Piercing plug, method for regenerating piercing plug, and regeneration facility line for piercing plug |
| CN101980802A (en) | 2008-03-27 | 2011-02-23 | 住友金属工业株式会社 | Method for producing seamless pipe |
| JP5169982B2 (en) * | 2009-03-03 | 2013-03-27 | 新日鐵住金株式会社 | Plug, piercing and rolling mill, and seamless pipe manufacturing method using the same |
| CN102534604B (en) * | 2012-02-09 | 2014-04-09 | 常州大学 | Method for prolonging service life of piercing plug for seamless steel tubes |
| US9333544B2 (en) * | 2012-04-24 | 2016-05-10 | Nippon Steel & Sumitomo Metal Corporation | Plug used in piercing machine |
| CN106148970A (en) * | 2015-04-16 | 2016-11-23 | 宁波金特信钢铁科技有限公司 | A kind of piercing plug for seamless steel tubes surface infiltration layer technique |
| CN105798063A (en) * | 2016-06-03 | 2016-07-27 | 江苏南山冶金机械制造有限公司 | Piercing point |
-
1997
- 1997-03-07 JP JP05314997A patent/JP3228169B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103240274A (en) * | 2013-05-10 | 2013-08-14 | 攀钢集团成都钢钒有限公司 | Piercing plug device of piercer, piercer and production method of seamless steel tubes |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10249412A (en) | 1998-09-22 |
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