JPH1088278A - Electric resistance welded tube excellent in liquid pressure bulging formability and its production - Google Patents
Electric resistance welded tube excellent in liquid pressure bulging formability and its productionInfo
- Publication number
- JPH1088278A JPH1088278A JP24764996A JP24764996A JPH1088278A JP H1088278 A JPH1088278 A JP H1088278A JP 24764996 A JP24764996 A JP 24764996A JP 24764996 A JP24764996 A JP 24764996A JP H1088278 A JPH1088278 A JP H1088278A
- Authority
- JP
- Japan
- Prior art keywords
- electric resistance
- resistance welded
- hydraulic bulge
- formability
- pipe
- 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
- Heat Treatment Of Sheet Steel (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、例えばサスペンシ
ョンアームなどの自動車足廻り部品、フレーム部品など
の自動車構造部品をなす液圧バルジ成形性に優れた電縫
鋼管およびその製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric resistance welded steel pipe having excellent hydraulic bulge formability and constituting a vehicle structural part such as a suspension part of a vehicle such as a suspension arm and a frame part.
【０００２】[0002]
【従来の技術】加工性に優れた電縫鋼管用熱延鋼帯に関
する従来技術として、例えば特開昭６０−１７０５３号
公報には、所定の化学組成を有する鋼を特定の組織とす
ることによって、電縫溶接後の伸び、偏平性、拡管性を
向上させることが開示されている。また、特開昭６０−
２１３５７号公報には、所定の化学組成を含有すること
で、偏平性、拡管性、溶接ビード部の切削性を向上させ
ることが開示されている。2. Description of the Related Art As a prior art relating to a hot rolled steel strip for an electric resistance welded steel pipe having excellent workability, for example, Japanese Patent Application Laid-Open No. Sho 60-17053 discloses that a steel having a predetermined chemical composition is formed into a specific structure. It is disclosed that the elongation, flatness, and expandability after electric resistance welding are improved. Also, Japanese Patent Application Laid-Open
Japanese Patent Application Laid-Open No. 21357 discloses that by containing a predetermined chemical composition, flatness, expandability, and machinability of a weld bead portion are improved.
【０００３】一方、加工性に優れた熱延鋼帯に関する従
来技術として、例えば特公昭６２−３７０８９号公報、
特公平１−４３００５号公報、特公平１−４６５８３号
公報、特公平２−４８６０８号公報、特公平４−２４４
１８号公報には、所定の化学組成を有する鋼の組織の構
成比を特定の割合とすることで鋼帯の伸びフランジ成形
性等を向上させることが開示されている。On the other hand, as a prior art relating to a hot-rolled steel strip excellent in workability, for example, Japanese Patent Publication No. Sho 62-37089,
Japanese Patent Publication No. 1-45005, Japanese Patent Publication No. 1-46583, Japanese Patent Publication No. 2-48608, Japanese Patent Publication No. 4-244
No. 18 discloses that the stretch flange formability of a steel strip is improved by setting the composition ratio of the structure of steel having a predetermined chemical composition to a specific ratio.
【０００４】[0004]
【発明が解決しようとする課題】電縫鋼管の成形方法と
して液圧バルジ成形は有力な加工手段であるが、大きな
張出しを行う場合、または曲げ加工後に張出しを行う場
合などでは、特開昭６０−１７０５３号公報あるいは特
開昭６０−２１３５７号公報に記載されたような従来技
術によって製造された電縫鋼管では、破断が生じるのを
防ぐために、中間焼鈍が必要である。The hydraulic bulge forming method is an effective processing method as a method for forming an electric resistance welded steel pipe. However, in the case of performing a large overhang or performing an overhang after bending, etc. In an electric resistance welded steel pipe manufactured by a conventional technique as described in JP-A-17053 or JP-A-60-21357, intermediate annealing is necessary in order to prevent breakage from occurring.
【０００５】一方、特公昭６２−３７０８９号公報、特
公平１−４３００５号公報、特公平１−４６５８３号公
報、特公平２−４８６０８号公報、特公平４−２４４１
８号公報などに示されたものをそのまま電縫鋼管に適用
しても造管歪みによる延性、特に一様伸び（Ｕ−Ｅｌ）
の低下が著しく、厳しい液圧バルジ成形を行うことは困
難である。On the other hand, Japanese Patent Publication No. Sho 62-37089, Japanese Patent Publication No. 1-43005, Japanese Patent Publication No. 1-46583, Japanese Patent Publication No. 2-48608, and Japanese Patent Publication No. 4-2441.
No. 8, the ductility due to pipe-forming distortion, especially uniform elongation (U-El) even when applied directly to ERW steel pipe
And it is difficult to perform severe hydraulic bulge forming.
【０００６】本発明は、これらの問題点を解消し、サス
ペンションアーム等の自動車足廻り部品、フレーム部品
など自動車構造部品の素材に要求される液圧バルジ成形
性に優れた電縫鋼管およびその製造方法を提供すること
を目的とする。The present invention solves these problems, and provides an electric resistance welded steel pipe excellent in hydraulic bulge formability required for materials of automobile structural parts such as suspension parts such as suspension arms and frame parts, and the production thereof. The aim is to provide a method.
【０００７】[0007]
【課題を解決するための手段】本発明に係る液圧バルジ
成形性に優れた電縫鋼管は、Ｃ：０．０１〜０．１％、
Ｓｉ：０．００５〜１．０％、Ｍｎ：０．２〜１．６
％、Ａｌ：０．０１〜０．０８％、Ｎ：０．０００６〜
０．００６％、Ｂ：０．０００２〜０．００５％を含
み、 Ｓ≦０．０１５％ ０．１≦Ｂ／Ｎ≦２ Ｔｉ＋Ｎｂ＋Ｖ≦０．０１％ で、残部が実質的に鉄よりなるものである。The electric resistance welded steel pipe excellent in hydraulic bulge formability according to the present invention has C: 0.01 to 0.1%,
Si: 0.005 to 1.0%, Mn: 0.2 to 1.6
%, Al: 0.01 to 0.08%, N: 0.0006 to
0.006%, B: 0.0002 to 0.005%, S ≦ 0.015% 0.1 ≦ B / N ≦ 2 Ti + Nb + V ≦ 0.01%, with the balance being substantially iron It is.
【０００８】また、液圧バルジ成形性に優れた電縫鋼管
の製造方法は、重量で、Ｃ：０．０１〜０．１％、Ｓ
ｉ：０．００５〜１．０％、Ｍｎ：０．２〜１．６％、
Ａｌ：０．０１〜０．０８％、Ｎ：０．０００６〜０．
００６％、Ｂ：０．０００２〜０．００５％を含み、 Ｓ≦０．０１５％ ０．１≦Ｂ／Ｎ≦２ Ｔｉ＋Ｎｂ＋Ｖ≦０．０１％ で、残部が実質的に鉄よりなるスラブを熱間圧延後ラン
ナウト中での６００〜７２０℃で２秒以上温度保持ある
いは徐冷の後３５０〜５５０℃で巻取り、８０％以上の
フェライトと残部ベイナイト組織とした鋼帯を、幅絞り
率が１〜１０％になるように造管することにある。The method for producing an electric resistance welded steel pipe excellent in hydraulic bulge formability is as follows: C: 0.01 to 0.1% by weight;
i: 0.005 to 1.0%, Mn: 0.2 to 1.6%,
Al: 0.01-0.08%, N: 0.0006-0.
006%, B: 0.0002 to 0.005%, S ≦ 0.015% 0.1 ≦ B / N ≦ 2 Ti + Nb + V ≦ 0.01% After the cold rolling, the steel strip having the ferrite of 80% or more and the remaining bainite structure was retained at a temperature of 600 to 720 ° C. for 2 seconds or more in a runout or slowly cooled and then wound at 350 to 550 ° C. It is to make a tube so as to be 10% or less.
【０００９】また、前記電縫鋼管の電縫部あるいは全体
を５００〜７００℃で焼鈍することにある。[0009] Another object of the present invention is to anneal the electric resistance welded portion or the whole of the electric resistance welded steel pipe at 500 to 700 ° C.
【００１０】[0010]
【発明の実施の形態】本発明に係る液圧バルジ成形性に
優れた電縫鋼管の成分組成の限定理由は下記の通りであ
る。Ｃは所望量のベイナイトを生成させ、目標とする組
織を確保するために必須な元素である。添加量が重量比
で０．０１〜０．１％の間で、造管歪による液圧バルジ
成形性の低下が少なく、かつ液圧バルジ成形性に優れた
電縫鋼管が得られる。添加量がこれよりも多くとも、少
なくとも造管歪による延性の低下が大きくなり、液圧バ
ルジ成形性に優れた電縫鋼管は得られない。Ｓｉはフェ
ライトの生成を促進し、所望のフェライト量を確保する
ために有用な元素である。重量比で０．００５％未満で
は添加効果に乏しく、一方１．０％を越えると電縫溶接
部の液圧バルジ成形性が劣化するためこれを上限とす
る。Ｍｎは所望量のベイナイトを生成させ、目標とする
組織を確保するために必須な元素である。添加量が重量
比で０．２〜１．６％の間でベイナイトが微細に分散し
た組織が得られる。添加量が０．２％よりも少ないとパ
ーライト変態が起こり、また１．６％より多いとフェラ
イト変態が抑制され、いずれも所望の組織が得られず、
造管による液圧バルジ成形性の低下が大きくなる。Ａｌ
は脱酸元素として添加され、その添加効果は０．０１％
が下限であり、一方０．０８％を越えると介在物の増大
により液圧バルジ成形性が劣化する。Ｓは電縫部の液圧
バルジ成形性を劣化させることから０．０１５％以下と
することが必要である。Ｔｉ、Ｎｂ、Ｖの添加は造管歪
による液圧バルジ成形性の低下を抑制し、液圧バルジ成
形性に優れた電縫鋼管が得られる。過剰な添加はむしろ
造管歪による液圧バルジ成形性の低下が大きくなる。す
なわちＴｉ、Ｎｂ、Ｖの総計添加量が０．０１％を越え
ると液圧バルジ成形性の低下が大きくなるので、総計
０．０１％を添加量の上限とする。BEST MODE FOR CARRYING OUT THE INVENTION The reasons for limiting the component composition of an electric resistance welded steel pipe excellent in hydraulic bulge formability according to the present invention are as follows. C is an element essential for generating a desired amount of bainite and securing a target structure. When the amount of addition is in the range of 0.01 to 0.1% by weight, a reduction in hydraulic bulge formability due to pipe strain is small, and an electric resistance welded steel pipe excellent in hydraulic bulge formability can be obtained. Even if the addition amount is larger than this range, at least the ductility is significantly reduced due to pipe strain, and an ERW steel pipe excellent in hydraulic bulge formability cannot be obtained. Si is an element that promotes the formation of ferrite and is useful for securing a desired amount of ferrite. If the weight ratio is less than 0.005%, the effect of addition is poor. On the other hand, if it exceeds 1.0%, the hydraulic bulge formability of the electric resistance welded portion deteriorates. Mn is an element essential for generating a desired amount of bainite and securing a target structure. When the amount of addition is between 0.2 and 1.6% by weight, a structure in which bainite is finely dispersed is obtained. If the addition amount is less than 0.2%, pearlite transformation occurs, and if it is more than 1.6%, ferrite transformation is suppressed, and any desired structure cannot be obtained.
The decrease in hydraulic bulge formability due to pipe formation is large. Al
Is added as a deoxidizing element and its effect is 0.01%
Is the lower limit. On the other hand, if it exceeds 0.08%, the increase in inclusions deteriorates hydraulic bulge formability. Since S deteriorates hydraulic bulge formability of the electric resistance welded portion, it is necessary to set S to 0.015% or less. Addition of Ti, Nb, and V suppresses a decrease in hydraulic bulge formability due to pipe forming distortion, and an ERW steel pipe excellent in hydraulic bulge formability can be obtained. Excessive addition rather increases the hydraulic bulge formability due to tube forming distortion. That is, if the total added amount of Ti, Nb, and V exceeds 0.01%, the hydraulic bulge formability is greatly reduced, so the total added amount is made 0.01% as the upper limit.
【００１１】Ｎは０．００６％を越えると液圧バルジ成
形性が低下するのでこれを上限とする。０．０００６％
より少ないと仕上げスタンド間でＡｌＮとして析出せ
ず、オーステナイト粒が粗大化し、液圧バルジ成形性が
低下するのでこれを下限とする。Ｂは０．０００２％以
上添加でＮの液圧バルジ成形性への悪影響を無害化する
効果があり、添加により液圧バルジ成形性が向上する。
この液圧バルジ成形性改善効果はＢ／Ｎ比が０．１〜２
の間で著しい。一方、添加量が０．００２％を超えると
かえって液圧バルジ成形性が低下するのでこれを上限と
する。図１にＮ、Ｂ添加量と液圧バルジ成形性との関係
を示す。ここで液圧バルジ成形性は６０．５mmφ×２．
６mmｔの電縫鋼管（直管）、およびこれを曲げ半径２０
０mmＲで９０°に曲げ加工した（曲げ管）に内側から液
圧を付与し、破断時の周長変化率（ｄ0 ）で評価した。
図１において（ａ）は直管、（ｂ）が曲げ管についての
データ（丸付き数値）である。ＮおよびＢ元素が本発明
の規定範囲にある場合、すなわちＮ：０．０００６〜
０．００６％、Ｂ：０．０００２〜０．００５％を含
み、かつ０．１≦Ｂ／Ｎ≦２の場合には、直管で２５％
以上、曲げ管で１５％以上の高い周長変化率を示し、液
圧バルジ成形性に優れていることがわかる。If N exceeds 0.006%, the hydraulic bulge formability decreases, so this is made the upper limit. 0.0006%
If the amount is smaller than the above, AlN does not precipitate between the finishing stands, austenite grains are coarsened, and hydraulic bulge formability is reduced. B has an effect of rendering the adverse effect of N on hydraulic bulge formability harmless when added in an amount of 0.0002% or more, and the addition improves the hydraulic bulge formability.
This hydraulic bulge formability improvement effect is obtained when the B / N ratio is 0.1 to 2
Notable among. On the other hand, if the addition amount exceeds 0.002%, the hydraulic bulge formability is rather lowered, so this is made the upper limit. FIG. 1 shows the relationship between the amounts of N and B added and the hydraulic bulge formability. Here, the hydraulic bulge formability is 60.5 mmφ × 2.
ERW steel pipe (straight pipe) of 6 mmt and bending radius of 20 mm
A hydraulic pressure was applied to the inside (bent pipe) bent at 90 ° at 0 mmR from the inside, and evaluated by the rate of change in circumferential length at break (d 0 ).
In FIG. 1, (a) shows data (circled numerical values) for a straight pipe and (b) shows data for a bent pipe. When the N and B elements are within the specified range of the present invention, that is, N: 0.0006 to
0.006%, B: 0.0002 to 0.005%, 25% in the case of 0.1 ≦ B / N ≦ 2
As described above, the bent pipe shows a high rate of change in the circumferential length of 15% or more, which indicates that the hydraulic bulge formability is excellent.
【００１２】上記成分組成を有する電縫鋼管は熱延鋼帯
を素材としており、該熱延鋼帯とするべく熱延に供され
るスラブは、連続鋳造後一旦Ａ3 変態点以下まで冷却し
てから再加熱してもよいし、連続鋳造後連続的に熱間圧
延を行ってもよい。[0012] The above electric resistance welded steel pipe having a chemical composition has a material of hot-rolled steel strip, the slab is subjected to hot rolling so as to obtain the heat-rolled steel strip, cooled once after continuous casting to below A 3 transformation point And then re-heated, or may be subjected to continuous hot rolling after continuous casting.
【００１３】前記熱間圧延による仕上圧延後の鋼帯は、
巻き取られるまでのランナウト中での６００〜７２０℃
の温度域で２秒以上温度保持あるいは徐冷しなければな
らない。この温度域での保持時間が２秒に満たないか徐
冷されないときは前記所望ののフェライト量が得られず
液圧バルジ成形性が低下する。The steel strip after finish rolling by the hot rolling is
600-720 ° C in runout until wound
The temperature must be kept for at least 2 seconds in the temperature range or slowly cooled. If the holding time in this temperature range is less than 2 seconds or if the cooling is not performed, the desired amount of ferrite cannot be obtained, and the hydraulic bulge formability decreases.
【００１４】前記仕上圧延後の鋼帯はミクロ組織の第２
相をベイナイト組織とするために巻取温度を３５０〜５
５０℃とする必要がある。巻取温度が５５０℃を越える
とパーライトが生成するため、造管歪による液圧バルジ
成形性の低下が大きくなる。一方３５０℃未満ではマル
テンサイトが生成し鋼帯での強度が増すことにより造管
歪による液圧バルジ成形性の低下が大きくなる。The steel strip after the finish rolling has a second microstructure.
The winding temperature is set to 350 to 5 so that the phase has a bainite structure.
It needs to be 50 ° C. If the winding temperature exceeds 550 ° C., pearlite is generated, and the reduction in hydraulic bulge formability due to distortion in pipe formation increases. On the other hand, when the temperature is lower than 350 ° C., martensite is generated and the strength of the steel strip is increased, so that a decrease in hydraulic bulge formability due to pipe forming distortion is increased.
【００１５】電縫鋼管の液圧バルジ成形性は、鋼成分、
鋼帯のミクロ組織に加えて、成形による歪量の影響もう
ける。成形による幅絞り率が１０％を越えると液圧バル
ジ成形性の低下が著しくなるため、これを上限とする。
また成形による幅絞り率が１％に満たないと周方向での
液圧バルジ成形性が不均一となり、成形性が相対的に低
い部位に歪みが集中し、液圧バルジ成形性を低下させる
ため、これを下限とする。なお、幅絞り率は次式によ
る。 幅絞り率＝｛［スリット幅］−π（［外径］−［板
厚］）｝／π（［外径］−［板厚］）×（１００％） 図２に幅絞り率と液圧バルジ成形性との関係を示す。幅
絞り率が１〜１０％の範囲で、直管は２５％以上、曲げ
管で１５％以上の高い周長変化率が得られ、液圧バルジ
成形性に優れていることがわかる。The hydraulic bulge formability of the ERW steel pipe is determined by the steel component,
In addition to the microstructure of the steel strip, it is affected by the amount of strain caused by forming. When the width reduction ratio by molding exceeds 10%, the hydraulic bulge formability significantly decreases, so this is set as the upper limit.
If the width reduction ratio by molding is less than 1%, the hydraulic bulge formability in the circumferential direction becomes non-uniform, and strain concentrates on a portion where the formability is relatively low, and the hydraulic bulge formability decreases. , And this is the lower limit. The width reduction ratio is determined by the following equation. Width drawing ratio = {[slit width] −π ([outer diameter] − [plate thickness])} / π ([outer diameter] − [plate thickness]) × (100%) FIG. This shows the relationship with bulge formability. When the width reduction ratio is in the range of 1 to 10%, a high circumferential length change rate of 25% or more for a straight pipe and 15% or more for a bent pipe is obtained, indicating that the hydraulic bulge formability is excellent.
【００１６】上記のような所定の成分組成を有し、上記
製造条件によって得られる８０％以上のフェライトと残
部ベイナイトからなる組織を有する熱延鋼帯を、成形に
よる幅絞り率が１〜１０％で造管された電縫鋼管は、造
管歪による液圧バルジ成形性低下量が小さく、かつ造管
後に優れた液圧バルジ成形性を有する理由は次のように
考えられる。無加工の熱延鋼帯においてはフェライト分
率の高いものほど液圧バルジ成形性が高い。しかし、プ
レーンなフェライト組織は造管等の加工硬化に伴う液圧
バルジ成形性低下が著しい。これは加工時に活動する転
位がすべり面にそって均一にすべり加工硬化を起こすた
めであると考えられる。これに対して、２０％未満のベ
イナイトを含ませると、転位のすべりが不均一に起こ
り、ある程度加工が進行しても可動転位密度が高く、液
圧バルジ成形性の低下が抑制されるものと考えられる。
さらに液圧バルジ成形性に悪影響をおよぼすＮをＢによ
り無害化することで液圧バルジ成形性の高い電縫鋼管が
得られる。A hot-rolled steel strip having the above-mentioned predetermined component composition and having a structure composed of 80% or more of ferrite and the balance of bainite obtained by the above-mentioned manufacturing conditions is obtained by forming a sheet with a width reduction ratio of 1 to 10%. The reason why the ERW steel pipe formed by the method described above has a small decrease in hydraulic bulge formability due to pipe forming distortion and has excellent hydraulic bulge formability after pipe formation is considered as follows. In an unprocessed hot-rolled steel strip, the higher the ferrite fraction, the higher the hydraulic bulge formability. However, the plain ferrite structure has a remarkable decrease in hydraulic bulge formability due to work hardening such as pipe making. It is considered that this is because dislocations active during processing cause slip work hardening uniformly along the slip surface. On the other hand, if less than 20% of bainite is contained, slip of dislocations occurs unevenly, and even if processing proceeds to some extent, the density of movable dislocations is high, and a decrease in hydraulic bulge formability is suppressed. Conceivable.
Further, by detoxifying N, which has an adverse effect on hydraulic bulge formability, with B, an electric resistance welded steel pipe having high hydraulic bulge formability can be obtained.
【００１７】[0017]
【実施例】次に、本発明を適用して得られた電縫鋼管に
ついて具体的に説明する。 （実施例１）表１に示す８種の鋼を溶製し、表２に示す
ように本発明に規定した熱延条件、造管条件にて６０．
５φ×２．６mmｔの電縫鋼管に造管した。これらの鋼管
を直管のまま或いは２００mmＲ−９０°の曲げ加工後に
液圧バルジ試験を行い周長変化率を評価した。本発明成
分を満足する鋼Ａ〜Ｆは直管、曲げ管の何れにおいても
比較鋼Ｇ、Ｈに比べ高い液圧バルジ成形性を示す。Next, an electric resistance welded steel pipe obtained by applying the present invention will be specifically described. (Example 1) Eight kinds of steels shown in Table 1 were melted and, as shown in Table 2, under the hot rolling conditions and tube forming conditions specified in the present invention.
The pipe was formed into an electric resistance welded steel pipe of 5φ × 2.6 mmt. These steel pipes were subjected to a hydraulic bulge test as they were, either straight or after bending by 200 mm R-90 °, to evaluate the rate of change in circumferential length. The steels A to F satisfying the components of the present invention show higher hydraulic bulge formability than the comparative steels G and H in both straight pipes and bent pipes.
【００１８】[0018]
【表１】 [Table 1]
【００１９】[0019]
【表２】 [Table 2]
【００２０】（実施例２）前記した鋼Ａ〜Ｆを用いて表
３に示すように熱延条件、造管条件を種々変化させて製
造した鋼帯を、６０．５φ×２．６mmｔの電縫鋼管に造
管した。これらの鋼管を直管のまま或いは２００mmＲ−
９０°の曲げ加工後に液圧バルジ試験を行い周長変化率
を評価した。熱延条件、ミクロ組織、造管条件が本発明
で規定した条件を満たしている鋼管は、直管、曲げ管の
何れにおいても比較例に比べ高い液圧バルジ成形性を示
す。(Example 2) As shown in Table 3, a steel strip manufactured by using the above-mentioned steels A to F and changing the hot rolling conditions and the pipe forming conditions variously was subjected to a 60.5 φ × 2.6 mmt electric wire. It was made into a sewn steel pipe. Use these steel pipes as straight pipes or 200mmR-
After bending at 90 °, a hydraulic bulge test was performed to evaluate the rate of change in circumference. A steel pipe whose hot rolling conditions, microstructure, and pipe forming conditions satisfy the conditions specified in the present invention shows higher hydraulic bulge formability in both straight pipes and bent pipes than the comparative example.
【００２１】[0021]
【表３】 [Table 3]
【００２２】[0022]
【発明の効果】以上のように本発明によれば、サスペン
ションアーム等の自動車構造部材に用いられる液圧バル
ジ成形性に優れた電縫鋼管が得られる。As described above, according to the present invention, an electric resistance welded steel pipe excellent in hydraulic bulge formability and used for automobile structural members such as suspension arms can be obtained.
【図面の簡単な説明】[Brief description of the drawings]
【図１】本発明の電縫鋼管のＮ、Ｂ添加量と直管および
曲げ管の液圧バルジ成形時の周長増加率との関係を示す
グラフ図である。FIG. 1 is a graph showing the relationship between the amounts of N and B added to an ERW steel pipe according to the present invention and the rate of increase in circumferential length of a straight pipe and a bent pipe during hydraulic bulge forming.
【図２】幅絞り率と直管および曲げ管の液圧バルジ成形
時の周長増加率との関係を示すグラフ図である。FIG. 2 is a graph showing a relationship between a width reduction ratio and a circumferential length increase rate at the time of hydraulic bulge forming of a straight pipe and a bent pipe.
Claims (3)
ｉ：０．００５〜１．０％、Ｍｎ：０．２〜１．６％、
Ａｌ：０．０１〜０．０８％、Ｎ：０．０００６〜０．
００６％、Ｂ：０．０００２〜０．００５％を含み、 Ｓ≦０．０１５％ ０．１≦Ｂ／Ｎ≦２ Ｔｉ＋Ｎｂ＋Ｖ≦０．０１％ で、残部が実質的に鉄よりなることを特徴とする液圧バ
ルジ成形性に優れた電縫鋼管。1. C: 0.01 to 0.1% by weight, S
i: 0.005 to 1.0%, Mn: 0.2 to 1.6%,
Al: 0.01-0.08%, N: 0.0006-0.
006%, B: 0.0002 to 0.005%, S ≦ 0.015% 0.1 ≦ B / N ≦ 2 Ti + Nb + V ≦ 0.01%, with the balance being substantially iron ERW steel pipe with excellent hydraulic bulge formability.
ｉ：０．００５〜１．０％、Ｍｎ：０．２〜１．６％、
Ａｌ：０．０１〜０．０８％、Ｎ：０．０００６〜０．
００６％、Ｂ：０．０００２〜０．００５％を含み、 Ｓ≦０．０１５％ ０．１≦Ｂ／Ｎ≦２ Ｔｉ＋Ｎｂ＋Ｖ≦０．０１％ で、残部が実質的に鉄よりなるスラブを熱間圧延後ラン
ナウト中での６００〜７２０℃で２秒以上温度保持ある
いは徐冷の後３５０〜５５０℃で巻取り、８０％以上の
フェライトと残部ベイナイト組織とした鋼帯を、幅絞り
率が１〜１０％になるように造管することを特徴とする
液圧バルジ成形性に優れた電縫鋼管の製造方法。2. C: 0.01-0.1% by weight, S
i: 0.005 to 1.0%, Mn: 0.2 to 1.6%,
Al: 0.01-0.08%, N: 0.0006-0.
006%, B: 0.0002 to 0.005%, S ≦ 0.015% 0.1 ≦ B / N ≦ 2 Ti + Nb + V ≦ 0.01% After the cold rolling, the steel strip having the ferrite of 80% or more and the remaining bainite structure was retained at a temperature of 600 to 720 ° C. for 2 seconds or more in a runout or slowly cooled and then wound at 350 to 550 ° C. A method for producing an electric resistance welded steel pipe having excellent hydraulic bulge formability, characterized in that the pipe is formed so as to be 10% to 10%.
００〜７００℃で焼鈍することを特徴とする請求項１ま
たは請求項２記載の液圧バルジ成形性に優れた電縫鋼管
の製造方法。3. The electric resistance welded portion or the whole of the electric resistance welded steel pipe
The method for producing an electric resistance welded steel pipe excellent in hydraulic bulge formability according to claim 1 or 2, wherein annealing is performed at 00 to 700 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24764996A JP3533844B2 (en) | 1996-09-19 | 1996-09-19 | ERW steel pipe excellent in hydraulic bulge formability and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24764996A JP3533844B2 (en) | 1996-09-19 | 1996-09-19 | ERW steel pipe excellent in hydraulic bulge formability and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1088278A true JPH1088278A (en) | 1998-04-07 |
| JP3533844B2 JP3533844B2 (en) | 2004-05-31 |
Family
ID=17166636
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24764996A Expired - Fee Related JP3533844B2 (en) | 1996-09-19 | 1996-09-19 | ERW steel pipe excellent in hydraulic bulge formability and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3533844B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005056856A1 (en) * | 2003-12-12 | 2005-06-23 | Jfe Steel Corporation | Steel product for structural member of automobile and method for production thereof |
| JP2007217736A (en) * | 2006-02-15 | 2007-08-30 | Jfe Steel Kk | High-tensile welded steel pipe for automobile structural member, and producing method thereof |
| DE102007030207A1 (en) * | 2007-06-27 | 2009-01-02 | Benteler Automobiltechnik Gmbh | Use of a high-strength steel alloy for producing high-strength and good formability blasting tubes |
| WO2020094684A1 (en) * | 2018-11-06 | 2020-05-14 | Salzgitter Flachstahl Gmbh | Interior high pressure-formed component made of steel, use of a steel for precursors for producing an interior high pressure-formed component, and precursor therefor |
-
1996
- 1996-09-19 JP JP24764996A patent/JP3533844B2/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005056856A1 (en) * | 2003-12-12 | 2005-06-23 | Jfe Steel Corporation | Steel product for structural member of automobile and method for production thereof |
| US8747578B2 (en) | 2003-12-12 | 2014-06-10 | Jfe Steel Corporation | Steel for structural part of automobile and method for producing the same |
| JP2007217736A (en) * | 2006-02-15 | 2007-08-30 | Jfe Steel Kk | High-tensile welded steel pipe for automobile structural member, and producing method thereof |
| DE102007030207A1 (en) * | 2007-06-27 | 2009-01-02 | Benteler Automobiltechnik Gmbh | Use of a high-strength steel alloy for producing high-strength and good formability blasting tubes |
| WO2020094684A1 (en) * | 2018-11-06 | 2020-05-14 | Salzgitter Flachstahl Gmbh | Interior high pressure-formed component made of steel, use of a steel for precursors for producing an interior high pressure-formed component, and precursor therefor |
| EP3877563A1 (en) * | 2018-11-06 | 2021-09-15 | Salzgitter Flachstahl GmbH | Interior high pressure-formed component made of steel, use of a steel for precursors for producing an interior high pressure-formed component, and precursor therefor |
| CN113423854A (en) * | 2018-11-06 | 2021-09-21 | 萨尔茨吉特液压成型有限責任兩合公司 | Steel inner high-pressure profiled part and use of steel in a semi-finished product for producing an inner high-pressure profiled part, and semi-finished product therefor |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3533844B2 (en) | 2004-05-31 |
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