JPH0543980A - High strength resistance welded tube for automobile excellent in toughness in weld zone - Google Patents
High strength resistance welded tube for automobile excellent in toughness in weld zoneInfo
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- JPH0543980A JPH0543980A JP22645591A JP22645591A JPH0543980A JP H0543980 A JPH0543980 A JP H0543980A JP 22645591 A JP22645591 A JP 22645591A JP 22645591 A JP22645591 A JP 22645591A JP H0543980 A JPH0543980 A JP H0543980A
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は、引張強さ：７０〜１
２０kgf/mm2 の高強度と高い疲労特性を備えると共に溶
接部靱性にも優れ、プロペラシャフトやインパクトバ−
等に適用して優れた性能を発揮する自動車用高強度電縫
鋼管に関するものである。BACKGROUND OF THE INVENTION The present invention has a tensile strength of 70 to 1
It has a high strength of 20 kgf / mm 2 and high fatigue characteristics, as well as excellent toughness in the welded part, and a propeller shaft and impact bar.
The present invention relates to a high-strength electric resistance welded steel pipe for automobiles that exhibits excellent performance when applied to, for example.
【０００２】[0002]
【従来技術とその課題】近年、軽量化推進のため自動車
用構造部材に対する薄肉・小型化の要求は一段と強くな
っており、そのためプロペラシャフト，インパクトバ−
等といった自動車用管状部材にも更なる高強度化が望ま
れるようになってきている。ただ、自動車用構造部材の
使用状態を考慮した場合、上記要求に応えるには単に静
的な強度を向上させるだけでは不十分であり、荷重の繰
り返し負荷に対する耐久性（疲労特性）をも同時に向上
させることが必要となる。2. Description of the Related Art In recent years, there has been an increasing demand for thinner and smaller structural members for automobiles in order to promote weight reduction. Therefore, propeller shafts and impact bars are being demanded.
There is a growing demand for higher strength in tubular members for automobiles such as. However, considering the usage of structural members for automobiles, it is not enough to simply improve the static strength to meet the above requirements, and the durability (fatigue property) against repeated load is also improved. Will be required.
【０００３】ところで、従来、構造用の管状部材に高強
度電縫鋼管を適用する際には a) 自動車用構造部材としての電縫鋼管は実車に装着さ
れる時に他の部材との溶接がなされるが、その際、継手
溶接部において軟化が生じ、高強度電縫鋼管の適用によ
る引張強度の増加に対応した疲労特性の向上が得られな
い， b) また、鋼管製造時の電縫溶接に目を向けると、高強
度鋼ほど電縫溶接部やその熱影響部に靱性低下が生じや
すく、電縫溶接部近傍が疲労亀裂の発生・伝播の経路と
なって疲労寿命の低下を招く傾向がある， 等の問題を取り除く必要があった。By the way, conventionally, when applying a high-strength electric resistance welded steel pipe to a structural tubular member, a) The electric resistance welded steel pipe as a structural member for automobiles is welded to other members when mounted on an actual vehicle. However, at that time, softening occurs in the joint weld, and the improvement in fatigue properties corresponding to the increase in tensile strength due to the application of high-strength ERW steel pipe cannot be obtained. Looking at it, the higher the strength of the steel, the more likely it is that toughness will decrease in the electric resistance welded part and its heat-affected zone, and the vicinity of the electric resistance welded part will tend to become a path for fatigue crack initiation and propagation, leading to a reduction in fatigue life. There was a need to eliminate problems such as "Yes".
【０００４】もっとも、継手溶接部の軟化問題に対して
は、例えば特開平２−１９７５２５号公報にも記載され
ているように、鋼材の成分としてNb，Cr，Moを複合添加
すると共に熱延条件を工夫して継手溶接熱影響部の硬度
低下を抑制する技術が知られている。しかし、このよう
な合金元素を含む鋼材では電縫溶接部及びその熱影響部
の靱性低下を抑えることができず、疲労寿命の低下は避
けられなかった。However, as to the problem of softening of the welded joint, as described in, for example, Japanese Patent Application Laid-Open No. 2-197525, Nb, Cr, and Mo are added as components of the steel material together with hot rolling conditions. It is known to devise a method to suppress the decrease in hardness of the joint heat-affected zone. However, with steel materials containing such alloying elements, it is not possible to suppress the reduction in toughness of the electric resistance welded portion and its heat-affected zone, and it is inevitable that the fatigue life is reduced.
【０００５】そこで、本発明が目的としたのは、電縫溶
接部や継手溶接部においても共に十分な疲労特性が備わ
った信頼性の高い自動車用高強度電縫鋼管を実現するこ
とであった。Therefore, the object of the present invention was to realize a highly reliable electric strength welded steel pipe for automobiles having sufficient fatigue characteristics in both the electric resistance welded portion and the joint welded portion. ..
【０００６】[0006]
【課題を解決するための手段】本発明者は、上記目的を
達成すべく数多くの実験を繰り返しながら研究を重ねた
結果、「電縫鋼管素材鋼の成分として特にNb，Mo，Ti及
びＢの複合添加を行うと共にそれらの含有割合を適正に
調整した場合には、 Nb，Moによる継手溶接部の硬度低下
抑制作用とTi，Ｂによる電縫溶接部靱性の改善作用とが
極めて好ましい状態で相乗され、 従来に見られない非常
に優れた溶接部靱性を備えた信頼性の高い高強度電縫鋼
管が実現される」との知見を得ることができた。Means for Solving the Problems The present inventor has conducted a number of experiments in order to achieve the above-mentioned object, and as a result of the research, he has found that "Nb, Mo, Ti and B as components of ERW steel material When composite addition is performed and the content ratios thereof are properly adjusted, Nb and Mo suppress the hardness decrease of the joint weld and the effect of Ti and B to improve the toughness of the electric resistance weld is synergistic in a very preferable state. Therefore, it is possible to obtain a highly reliable high-strength electric resistance welded pipe with extremely excellent weld toughness that has never been seen before. ”
【０００７】本発明は、上記知見事項等を基にして完成
されたものであり、 「電縫鋼管の成分組成を Ｃ：0.06〜0.30％（以降、 成分割合を表す％は重量％と
する),Si： 1.0％以下， Mn： 2.0％以下， Mo：
0.05〜 0.8％，Nb：0.01〜 0.005％， Ti： 0.005〜0.
04％， sol.Al： 0.005〜0.05％，Ｂ：0.0003〜0.0012
％， Ｎ： 0.008％以下を含むか、 或いは更に Cr： 1.5％以下， Ni： 3.0％以下， Cu： 1.0％以
下， Ｖ：0.10％以下のうちの１種以上をも含有し、 残
部がFe及び不可避的不純物なる成分組成に構成すること
により、 自動車用として十分に満足できる高い強度と優
れた溶接部靱性を確保した点」 に大きな特徴を有している。The present invention has been completed on the basis of the above-mentioned findings and the like. "The composition of the composition of the electric resistance welded steel pipe is C: 0.06 to 0.30% (hereinafter,% representing the composition ratio shall be% by weight). , Si: 1.0% or less, Mn: 2.0% or less, Mo:
0.05 to 0.8%, Nb: 0.01 to 0.005%, Ti: 0.005 to 0.
04%, sol.Al: 0.005 to 0.05%, B: 0.0003 to 0.0012
%, N: 0.008% or less, or Cr: 1.5% or less, Ni: 3.0% or less, Cu: 1.0% or less, V: 0.10% or less, and the balance Fe. In addition, the composition of the inevitable impurities ensured high strength and excellent weld toughness, which are sufficiently satisfactory for automobiles. "
【０００８】[0008]
【作用】即ち、本発明に係わる自動車用高強度電縫鋼管
は、適量のNb，Mo添加によって発揮されるところの「非
常に微細で熱的に安定した組織が実現されて継手溶接部
の硬度低下を効果的に抑制する作用」と、これと共に微
量のTi，Ｂを添加することによって発揮される「継手溶
接部の疲労特性を更に向上させると同時に、 電縫溶接部
の靱性を著しく改善して該部位の疲労特性を格段に向上
させる作用」とを巧みに相乗させてなるものであるが、
以下、本発明において電縫鋼管の成分組成を前記の如く
に限定した理由を説明する。In other words, the high strength electric resistance welded steel pipe for automobiles according to the present invention has the effect that "a very fine and thermally stable structure is realized and the hardness of the welded portion of the joint is achieved by adding an appropriate amount of Nb and Mo. "The effect of effectively suppressing the decrease" and "the effect of adding a small amount of Ti and B together with it" further improves the fatigue characteristics of the joint weld and at the same time significantly improves the toughness of the electric resistance weld. And the effect of significantly improving the fatigue characteristics of the part ".
The reason why the composition of the electric resistance welded steel pipe is limited as described above in the present invention will be described below.
【０００８】(a) Ｃ Ｃは電縫鋼管に高強度を確保するのに重要な元素である
が、その含有量が0.06％未満では７０キロ級以上の引張
強度を得ることができない。一方、Ｃ含有量が0.30％を
超えると継手溶接部と電縫溶接部の靱性が低下する。従
って、Ｃ含有量は0.06〜0.30％と定めた。(A) CC C is an important element for ensuring high strength in the electric resistance welded steel pipe, but if its content is less than 0.06%, tensile strength of 70 kg or more cannot be obtained. On the other hand, if the C content exceeds 0.30%, the toughness of the joint weld and the electric resistance weld will decrease. Therefore, the C content is set to 0.06 to 0.30%.
【０００９】(b) Si Siは脱酸元素として重要なだけでなく引張強度の確保に
も必要であるが、 1.0％を超えて含有させると母材，継
手溶接部及び電縫溶接部の靱性に悪影響を及ぼすと共
に、電縫溶接部に溶接欠陥が発生しやすくなることか
ら、Si含有量は 1.0％以下と定めた。(B) Si Si is important not only as a deoxidizing element but also for ensuring the tensile strength, but if it is contained in excess of 1.0%, the toughness of the base material, joint welds and electric resistance welds will be high. In addition to adversely affecting the weldability, and because weld defects easily occur in the electric resistance welded portion, the Si content was set to 1.0% or less.
【００１０】(c) Mn Mnも電縫鋼管に高強度を得るのに必要な元素であり、ま
た組織の微細化に有効で疲労特性を向上させる作用を有
しているが、 2.0％を超えて含有させると電縫溶接部に
欠陥が発生しやすくなり却って電縫溶接部靱性の低下を
招くことから、Mn含有量は 2.0％以下と定めた。(C) Mn Mn is also an element necessary for obtaining high strength in the electric resistance welded steel pipe, and it is effective in refining the structure and has an effect of improving fatigue characteristics, but it exceeds 2.0%. If it is contained in the electric resistance welded portion, defects are likely to occur and the toughness of the electric resistance welded portion is deteriorated. Therefore, the Mn content is set to 2.0% or less.
【００１１】(d) Mo Moは、固溶強化を通じて電縫鋼管の高強度化と同時に、
継手溶接ＨＡＺ部の軟化を抑制して構造部材としての疲
労特性を向上させる作用を有しているが、その含有量が
0.05％未満では前記作用による所望の効果が得られず、
一方、 0.8％を超えて含有させると母材部，溶接部（電
縫部及び継手部）とも靱性が低下するようになることか
ら、Mo含有量は0.05〜 0.8％と定めた。(D) Mo Mo strengthens the electric resistance welded steel pipe through solid solution strengthening, and at the same time,
It has the effect of suppressing the softening of the joint weld HAZ part and improving the fatigue properties as a structural member, but its content is
If it is less than 0.05%, the desired effect due to the above action cannot be obtained,
On the other hand, if the content exceeds 0.8%, the toughness of the base metal part and the welded parts (electrically welded part and joint part) will decrease, so the Mo content was set to 0.05 to 0.8%.
【００１２】(e) Nb Nbは、主として析出物の生成により電縫鋼管の強度上昇
をもたらすと同時に、組織を微細化して母材の靱性を向
上させる作用を有している。また、Nbは継手溶接ＨＡＺ
部の軟化を抑制すると共に、電縫溶接部及びそのＨＡＺ
部の靱性を向上させて疲労強度を改善する作用も有して
いる。しかし、Nb含有量が 0.005％未満では前記作用に
よる所望の効果が得られず、一方、0.10％を超えて含有
させると特に電縫溶接部の靱性低下を招くようになるこ
とから、Nb含有量は 0.005〜0.10％と定めた。(E) Nb Nb has the effect of increasing the strength of the electric resistance welded steel tube mainly by the formation of precipitates, and at the same time, refining the structure to improve the toughness of the base material. Nb is a welded HAZ joint.
Suppression of softening of the welded part and the electric resistance welded part and its HAZ
It also has the effect of improving the toughness of the part and improving the fatigue strength. However, if the Nb content is less than 0.005%, the desired effect due to the above-mentioned action cannot be obtained, while if the content exceeds 0.10%, the toughness of the electric resistance welded part is particularly deteriorated. Was set to 0.005 to 0.10%.
【００１３】(f) sol.Al Alは鋼の脱酸並びに微細化に有効な元素であるが、その
含有量がsol.Al量として 0.005％未満では所望の効果が
得られず、一方、0.05％を超えて含有させると電縫溶接
部靱性及び疲労特性に悪影響を及ぼすようになることか
ら、sol.Al含有量を 0.005〜0.05％と定めた。(F) sol.Al Al is an element effective for deoxidizing and refining steel, but if the content of sol.Al is less than 0.005%, the desired effect cannot be obtained, while 0.05 %, The sol.Al content was set to 0.005 to 0.05%.
【００１４】(g) Ｎ 鋼中のＮ含有量が 0.008％を超えると母材及び溶接部の
靱性が著しく劣化し、また疲労特性も低下することか
ら、Ｎ含有量を 0.008％以下と規制した。(G) When the N content in N steel exceeds 0.008%, the toughness of the base material and the welded part is significantly deteriorated and the fatigue properties are also deteriorated. Therefore, the N content is regulated to 0.008% or less. .
【００１５】(h) Ti及びＢ これらの成分は、複合添加によって電縫溶接部及びその
熱影響部の靱性を飛躍的に改善し優れた疲労特性を有す
る自動車用高強度電縫鋼管を実現する作用を有している
が、各成分の含有量範囲は次の理由により限定された。Ti Tiは、母材と電縫溶接部及び継手溶接部の微細化促進，
電縫溶接部の靱性改善を通じて電縫鋼管の疲労強度特性
を向上させる作用を有しているが、その含有量が 0.005
％未満では前記作用による所望の効果が期待できず、一
方、0.04％を超えて含有させると却って疲労強度が低下
するようになることから、Ti含有量は 0.005〜0.04％と
定めた。Ｂ Ｂも、Tiと同時に添加されることによって電縫溶接部及
び継手溶接部の微細化を促進し、電縫溶接部の靱性を改
善させる作用を発揮するが、その添加量が0.0003％未満
であると前記作用による所望の効果が期待できず、また
0.0012％を超えて含有させると却って疲労強度が低下す
ることから、Ｂ含有量は0.0003〜0.0012％と定めた。(H) Ti and B These components realize a high-strength electric resistance welded steel pipe for automobiles having a remarkable improvement in the toughness of the electric resistance welded portion and its heat-affected zone by the combined addition. Although it has an action, the content range of each component was limited for the following reasons. Ti Ti promotes miniaturization of base material, electric resistance welded joints and joint welds,
It has the effect of improving the fatigue strength characteristics of ERW steel pipes by improving the toughness of ERW welded parts, but its content is 0.005
If it is less than 0.1%, the desired effect due to the above-mentioned action cannot be expected, while if it exceeds 0.04%, the fatigue strength rather decreases, so the Ti content was set to 0.005 to 0.04%. BB also has the effect of promoting the refinement of the electric resistance welded portion and joint welded portion and improving the toughness of the electric resistance welded portion by being added together with Ti, but if the addition amount is less than 0.0003%. If so, the desired effect due to the above action cannot be expected, and
If the content exceeds 0.0012%, the fatigue strength rather decreases, so the B content was set to 0.0003 to 0.0012%.
【００１６】i) Cr，Ni，Cu及びＶ これらの成分は、何れも電縫鋼管の強度，靱性或いは疲
労特性を更に改善する効果を有しているので必要により
１種又は２種以上含有せしめられるが、個々成分の含有
量範囲は次の理由により限定された。Cr Crは鋼管の強度及び耐食性を向上させると共に、継手溶
接部の軟化を抑制する作用を有しているが、 1.5％を超
えて含有させると母材及び電縫溶接部の靱性が低下する
と共に電縫溶接部に溶接欠陥が発生しやすくなることか
ら、Cr含有量は1.5 ％以下と定めた。Ni Niは鋼管の強度，靱性及び耐食性を向上させる作用を有
しているが、 3.0％を超えて含有させると電縫溶接部の
靱性劣化を招く上、高価な元素でもあることから、Ni含
有量は 3.0％以下と定めた。Cu Cuには鋼管の強度及び耐食性を向上させる作用がある
が、 1.0％を超えて含有させると熱間加工性が低下し、
電縫溶接部靱性も低下することから、Cu含有量は1.0 ％
以下と定めた。Ｖ Ｖは析出物の生成を通じて鋼管の強度を高め、継手溶接
部の軟化抵抗を高める作用を有しているが、0.10％を超
えて含有させると母材及び電縫溶接部の靱性低下を招く
ことから、Ｖ含有量は0.10％以下と定めた。I) Cr, Ni, Cu and V All of these components have the effect of further improving the strength, toughness or fatigue characteristics of the electric resistance welded steel pipe, so one or more of them may be contained if necessary. However, the content range of each component was limited for the following reasons. Cr Cr has the effect of improving the strength and corrosion resistance of steel pipes and suppressing the softening of joint welds, but if it exceeds 1.5%, the toughness of the base metal and electric resistance welds will decrease and The content of Cr was set to 1.5% or less because welding defects are likely to occur in the electric resistance welded portion. Ni Ni has the effect of improving the strength, toughness and corrosion resistance of steel pipes, but if it exceeds 3.0%, it causes deterioration of the toughness of the electric resistance welded portion and is an expensive element. The amount was set to 3.0% or less. Cu Cu has the effect of improving the strength and corrosion resistance of steel pipes, but if it exceeds 1.0%, the hot workability will decrease,
The Cu content is 1.0% because the toughness of the electric resistance welded joint also decreases.
It was defined as the following. V V has the effect of increasing the strength of the steel pipe through the formation of precipitates and increasing the softening resistance of the joint weld, but if it is contained in excess of 0.10%, the toughness of the base metal and electric resistance weld will be reduced. Therefore, the V content is set to 0.10% or less.
【００１７】なお、母材及び溶接部の靱性，疲労特性に
対してはＰ，Ｓ等の不可避的不純物含有量はできるだけ
低い方が好ましい。しかし、これらの元素の低減にはコ
ストアップが伴うので、本発明の目的に対してはＰ含有
量は0.02％以下（望ましくは0.007 ％以下），Ｓ含有量
は 0.005％以下（望ましくは 0.001％以下）に抑えるの
が良い。It is preferable that the content of inevitable impurities such as P and S is as low as possible with respect to the toughness and fatigue characteristics of the base material and the welded portion. However, reduction of these elements is accompanied by cost increase. Therefore, for the purpose of the present invention, the P content is 0.02% or less (desirably 0.007% or less) and the S content is 0.005% or less (desirably 0.001%). It is better to keep the following).
【００１８】また、上記成分組成にて構成される“本発
明に係わる電縫鋼管”は、前記成分組成を有する素材鋼
を熱間圧延して鋼帯とし、これを通常の工程（鋼帯を管
状に成形した後、 高周波電流により相対向するエッジ部
を加熱して溶融し、 スクイズロ−ルにより加圧圧接して
製管する工程）で電縫鋼管とすることにより製造するこ
とができる。Further, the "electric resistance welded steel pipe according to the present invention" constituted by the above-mentioned component composition is obtained by hot rolling a raw material steel having the above-mentioned component composition into a steel strip, which is subjected to a normal process (steel strip formation). After being formed into a tubular shape, the edge portions facing each other are heated and melted by a high frequency current, and a process of producing pressure-welded pipes by a squeeze roll to produce an electric resistance welded steel pipe can be manufactured.
【００１９】続いて、本発明を実施例により更に具体的
に説明する。Next, the present invention will be described more specifically by way of examples.
【実施例】通常の溶製，鋳造，熱間圧延を施された熱延
鋼板を常法通りに製管し（管状への成形→相対向するエ
ッジ部の高周波電流による加熱・溶融→スクイズロ−ル
による加圧圧接）、表１に示す成分組成の電縫鋼管（外
形：６５mm，肉厚:1.6mm）を得た。[Example] A hot-rolled steel sheet that has been subjected to normal melting, casting, and hot rolling is manufactured in a conventional manner (molding into a tubular shape → heating / melting by a high-frequency current of opposite edges → squeeze roll- Pressure welding by means of a pressure gauge), and an electric resistance welded steel pipe (outer diameter: 65 mm, wall thickness: 1.6 mm) having the composition shown in Table 1 was obtained.
【００２０】次に、得られた各電縫鋼管から試験片を採
取し、“母材の引張強度”及び“電縫溶接部の靱性”を
調べた。なお、“電縫溶接部の靱性”については、「溶
接のまま」と「５００℃に３０分保持の熱処理を施した
後」の２通りにつき“−１０℃におけるシャルピ−吸収
エネルギ−”を調査し、これによって特性評価を行っ
た。これらの結果を表２に示す。Next, test pieces were taken from each of the obtained electric resistance welded steel pipes, and the "tensile strength of the base material" and "toughness of the electric resistance welded portion" were examined. As for "toughness of ERW welded part", "Charpy absorbed energy at -10 ° C" was investigated for each of "as-welded" and "after heat treatment at 500 ° C for 30 minutes". Then, the characteristic evaluation was performed by this. The results are shown in Table 2.
【００２１】[0021]
【表１】 [Table 1]
【００２２】[0022]
【表２】 [Table 2]
【００２３】表２に示される結果からも明らかなよう
に、本発明鋼管は何れも自動車用電縫鋼管として十分に
高い強度を有すると共に、従来鋼管に比べて著しく改善
された電縫溶接部靱性を有していることが分かる。As is clear from the results shown in Table 2, each of the steel pipes of the present invention has a sufficiently high strength as an electric resistance welded steel pipe for automobiles, and has a toughness of the electric resistance welded portion which is remarkably improved as compared with the conventional steel pipe. It turns out that it has.
【００２４】[0024]
【効果の総括】以上に説明した如く、この発明によれ
ば、自動車用として十分優れた溶接部靱性（継手溶接部
及び電縫溶接部の靱性）を備える高強度電縫鋼管を比較
的低コストで安定提供できるようになるなど、産業上極
めて有用な効果がもたらされる。[Summary of Effects] As described above, according to the present invention, a high-strength electric resistance welded steel pipe having sufficiently high weld toughness (toughness of joint weld and electric resistance weld) for automobiles is relatively low in cost. With this, stable effects can be provided with, and extremely useful effects in the industry are brought about.
─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───
【手続補正書】[Procedure amendment]
【提出日】平成３年９月２６日[Submission date] September 26, 1991
【手続補正１】[Procedure Amendment 1]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】請求項２[Name of item to be corrected] Claim 2
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【手続補正２】[Procedure Amendment 2]
【補正対象書類名】明細書[Document name to be amended] Statement
【補正対象項目名】０００７[Correction target item name] 0007
【補正方法】変更[Correction method] Change
【補正内容】[Correction content]
【０００７】 本発明は、上記知見事項等を基にして完
成されたものであり、 「電縫鋼管の成分組成を Ｃ：0.06〜0.30％（以降、 成分割合を表す％は重量％と
する),Si： 1.0％以下， Mn： 2.0％以下， Mo：
0.05〜 0.8％，Nb： 0.005〜0.10％， Ti： 0.005〜0.
04％，sol.Al： 0.005〜0.05％，Ｂ：0.0003〜0.0012
％， Ｎ： 0.008％以下を含むか、 或いは更に Cr： 1.5％以下， Ni： 3.0％以下， Cu： 1.0％以
下， Ｖ：0.10％以下のうちの１種以上をも含有し、残
部がFe及び不可避的不純物なる成分組成に構成すること
により、 自動車用として十分に満足できる高い強度と優
れた溶接部靱性を確保した点」 に大きな特徴を有している。The present invention has been completed based on the above findings and the like, “The composition of the composition of the electric resistance welded steel pipe is C: 0.06 to 0.30% (hereinafter,% representing the composition ratio is% by weight). , Si: 1.0% or less, Mn: 2.0% or less, Mo:
0.05 to 0.8%, Nb: 0.005 to 0.10%, Ti: 0.005 to 0.
04%, sol.Al: 0.005 to 0.05%, B: 0.0003 to 0.0012
%, N: 0.008% or less, or Cr: 1.5% or less, Ni: 3.0% or less, Cu: 1.0% or less, V: 0.10% or less, and the balance Fe. In addition, the composition of the composition of unavoidable impurities ensures high strength and excellent weld toughness, which are sufficiently satisfactory for automobiles. "
Claims (2)
以下，Mo：0.05〜 0.8％， Nb： 0.005〜0.10％， T
i： 0.005〜0.04％，sol.Al： 0.005〜0.05％， Ｂ：
0.0003〜0.0012％， Ｎ： 0.008％以下を含有し、残部
がFe及び不可避的不純物である成分組成を有して成るこ
とを特徴とする、溶接部靱性に優れた自動車用高強度電
縫鋼管。1. By weight ratio, C: 0.06 to 0.30%, Si: 1.0% or less, Mn: 2.0%
Below, Mo: 0.05-0.8%, Nb: 0.005-0.10%, T
i: 0.005 to 0.04%, sol.Al: 0.005 to 0.05%, B:
A high-strength electric resistance welded steel pipe for automobiles having excellent weld toughness, characterized by containing 0.0003 to 0.0012%, N: 0.008% or less, and the balance being a component composition of Fe and inevitable impurities.
以下，Mo：0.05〜 0.8％， Nb：0.01〜 0.005％， T
i： 0.005〜0.04％，sol.Al： 0.005〜0.05％， Ｂ：
0.0003〜0.0012％， Ｎ： 0.008％以下を含むと共に、
更に Cr： 1.5％以下， Ni： 3.0％以下， Cu： 1.0％
以下，Ｖ：0.10％以下のうちの１種以上をも含有し、残
部がFe及び不可避的不純物である成分組成を有して成る
ことを特徴とする、溶接部靱性に優れた自動車用高強度
電縫鋼管。2. By weight ratio, C: 0.06 to 0.30%, Si: 1.0% or less, Mn: 2.0%
Below, Mo: 0.05 to 0.8%, Nb: 0.01 to 0.005%, T
i: 0.005 to 0.04%, sol.Al: 0.005 to 0.05%, B:
0.0003 to 0.0012%, N: including 0.008% or less,
Cr: 1.5% or less, Ni: 3.0% or less, Cu: 1.0%
V: 0.10% or less, at least one of which is contained, the balance being Fe and inevitable impurities. ERW steel pipe.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22645591A JP3265591B2 (en) | 1991-08-12 | 1991-08-12 | High-strength ERW steel pipe for automobiles with excellent weld toughness |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22645591A JP3265591B2 (en) | 1991-08-12 | 1991-08-12 | High-strength ERW steel pipe for automobiles with excellent weld toughness |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0543980A true JPH0543980A (en) | 1993-02-23 |
| JP3265591B2 JP3265591B2 (en) | 2002-03-11 |
Family
ID=16845372
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22645591A Expired - Lifetime JP3265591B2 (en) | 1991-08-12 | 1991-08-12 | High-strength ERW steel pipe for automobiles with excellent weld toughness |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3265591B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5350561A (en) * | 1992-03-31 | 1994-09-27 | Nkk Corporation | Cr-Mo steel pipe and welding method thereof |
| WO1995004838A1 (en) * | 1993-08-04 | 1995-02-16 | Nippon Steel Corporation | High tensile strength steel having superior fatigue strength and weldability at welds and method for manufacturing the same |
| EP1640468A1 (en) * | 2003-05-28 | 2006-03-29 | Sumitomo Metal Industries, Ltd. | Oil well steel pipe to be placed under ground and be expanded |
| EP1693476A1 (en) * | 2003-12-12 | 2006-08-23 | JFE Steel Corporation | Steel product for structural member of automobile and method for production thereof |
-
1991
- 1991-08-12 JP JP22645591A patent/JP3265591B2/en not_active Expired - Lifetime
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5350561A (en) * | 1992-03-31 | 1994-09-27 | Nkk Corporation | Cr-Mo steel pipe and welding method thereof |
| WO1995004838A1 (en) * | 1993-08-04 | 1995-02-16 | Nippon Steel Corporation | High tensile strength steel having superior fatigue strength and weldability at welds and method for manufacturing the same |
| CN1040555C (en) * | 1993-08-04 | 1998-11-04 | 新日本制铁株式会社 | High tensile strength steel having superior fatigue strength and weldability at welds and method for manufacturing the same |
| EP1640468A1 (en) * | 2003-05-28 | 2006-03-29 | Sumitomo Metal Industries, Ltd. | Oil well steel pipe to be placed under ground and be expanded |
| EP1640468A4 (en) * | 2003-05-28 | 2006-09-13 | Sumitomo Metal Ind | Oil well steel pipe to be placed under ground and be expanded |
| EP1693476A1 (en) * | 2003-12-12 | 2006-08-23 | JFE Steel Corporation | Steel product for structural member of automobile and method for production thereof |
| EP1693476A4 (en) * | 2003-12-12 | 2009-07-22 | Jfe Steel Corp | 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3265591B2 (en) | 2002-03-11 |
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