JPH024944A - Steel for electric-resistance weld steel tube having excellent fatigue characteristics - Google Patents
Steel for electric-resistance weld steel tube having excellent fatigue characteristicsInfo
- Publication number
- JPH024944A JPH024944A JP15399288A JP15399288A JPH024944A JP H024944 A JPH024944 A JP H024944A JP 15399288 A JP15399288 A JP 15399288A JP 15399288 A JP15399288 A JP 15399288A JP H024944 A JPH024944 A JP H024944A
- Authority
- JP
- Japan
- Prior art keywords
- steel
- electric
- less
- excellent fatigue
- resistance weld
- 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
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 55
- 239000010959 steel Substances 0.000 title claims abstract description 55
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 7
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 7
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 7
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 7
- 229910052796 boron Inorganic materials 0.000 claims abstract description 6
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 5
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000012535 impurity Substances 0.000 claims abstract description 3
- 238000003466 welding Methods 0.000 claims description 7
- 238000004519 manufacturing process Methods 0.000 abstract description 8
- 239000000463 material Substances 0.000 abstract description 7
- 229910052799 carbon Inorganic materials 0.000 abstract description 6
- 229910052802 copper Inorganic materials 0.000 abstract description 6
- 230000001105 regulatory effect Effects 0.000 abstract description 3
- 230000000694 effects Effects 0.000 description 10
- 239000010949 copper Substances 0.000 description 9
- 238000010438 heat treatment Methods 0.000 description 7
- 239000003381 stabilizer Substances 0.000 description 4
- 238000009661 fatigue test Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000010791 quenching Methods 0.000 description 3
- 230000000171 quenching effect Effects 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- 230000002411 adverse Effects 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000746 Structural steel Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910021419 crystalline silicon Inorganic materials 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000005204 segregation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 150000003568 thioethers Chemical class 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Heat Treatment Of Articles (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、銅帯をロール成形、電気抵抗溶接して製造さ
れる電縫鋼管が構造用或いは機械構造用として用いられ
る際に優れた疲労特性を有する電縫鋼管の素材鋼に関す
る。Detailed Description of the Invention (Field of Industrial Application) The present invention provides excellent fatigue resistance when ERW steel pipes manufactured by roll forming and electric resistance welding copper strips are used for structural or mechanical structures. The present invention relates to material steel for electric resistance welded steel pipes having characteristics.
（従来の技術及び解決しようとする課題）近年、自動車
車体の軽量化対策の１つとして、足廻り部品、例えば、
走行安定性を保持するスタビライザーなどは、従来より
棒鋼で製造されていたが、シームレス鋼管或いは溶接鋼
管を用いた中空化が進んでいる。(Prior art and problems to be solved) In recent years, as one of the measures to reduce the weight of automobile bodies, suspension parts, for example,
Stabilizers and the like that maintain running stability have traditionally been manufactured from steel bars, but hollow steel pipes are increasingly being made using seamless steel pipes or welded steel pipes.
この場合、溶接鋼管によって中空状の足廻り部品を製造
するには、棒鋼による中実状のものに比べて、構造用部
材としての品質及び信頼性を確保するには、溶接部の健
全性が要求される。更に、これら部品には繰返し応力が
作用するので高い疲労特性が要求される。In this case, when manufacturing hollow suspension parts using welded steel pipes, the soundness of the welded parts is required to ensure quality and reliability as structural members, compared to solid steel bars. be done. Furthermore, since repeated stress acts on these parts, high fatigue properties are required.
ところで、中空化のための鋼管としては、表面性状及び
製造原価の点で有利となる電縫鋼管が多く適用されてい
る。この電縫鋼管用素材としては例えば、特開昭５８−
１２３８５８号公報に示されているようにＣ−Ｓｉ、Ｍ
ｎ、Ｃｒ量を焼入れ性（理想臨界直径）や炭素当量を考
慮して調整され、更に５ｏＱＡＱ、Ｔｊ、Ｂを添加した
ものがある。By the way, electric resistance welded steel pipes are often used as steel pipes for hollowing because they are advantageous in terms of surface quality and manufacturing cost. Examples of materials for this electric resistance welded steel pipe include JP-A-58-
As shown in Japanese Patent No. 123858, C-Si, M
There is one in which the amounts of n and Cr are adjusted in consideration of hardenability (ideal critical diameter) and carbon equivalent, and further 5oQAQ, Tj, and B are added.
しかし乍ら、捻り応力といった厳しい条件で使用される
場合では、素材に高い疲労特性製具備するよう配慮する
必要がある。However, when used under severe conditions such as torsional stress, care must be taken to ensure that the material has high fatigue properties.
本発明は、か＼る状況のもとでなされたものであって、
電縫鋼管がスタビライザーなどの部品に適用された場合
に、その使用時にねじりの繰返し応力が負荷されても溶
接部で破断して疲労特性を損うようなことがなく、優れ
た疲労特性を有する電縫鋼管用鋼を提供することを目的
とするものである。The present invention was made under such circumstances, and
When ERW steel pipes are applied to parts such as stabilizers, they do not break at the welds and lose fatigue properties even when subjected to repeated torsional stress during use, and have excellent fatigue properties. The purpose of this invention is to provide steel for electric resistance welded steel pipes.
（課題を解決するための手段）
前記目的を達成するため、本発明者らは、この種の電縫
鋼管が使用時に溶接部で破断する原因について検討した
。(Means for Solving the Problems) In order to achieve the above object, the present inventors investigated the cause of this type of electric resistance welded steel pipe breaking at the welded portion during use.
その結果、電縫鋼管の製造過程の溶接において、接合中
心部に第１図に示すような白色層が生成し、これが原因
で疲労特性が著しく低下することが判明した。As a result, it was found that during welding during the manufacturing process of electric resistance welded steel pipes, a white layer as shown in FIG. 1 was formed at the center of the joint, and that this caused a significant decline in fatigue properties.
すなわち、この白色層は周りの部分に比へてＣ１Ｓｉ、
Ｍｎなどの成分が低くなっており、硬度を測定するとこ
の白色層で低硬度となっている。スタビライザーなどの
部品として高い疲労強度を得るために焼入れ処理が施さ
れるが、この焼入れ処理後においても、白色層部分の硬
度は低くなっている（第２図）。このことは、鋼管の円
周方向において、強度が均一とはなっておらず、低強度
の領域が部分的ではあるが円周方向に存在し、これが鋼
管の長さ方向全長に亘り存在しているものと考察される
。That is, this white layer has C1Si,
Components such as Mn are low, and when hardness is measured, this white layer has low hardness. Hardening is performed to obtain high fatigue strength for parts such as stabilizers, but even after this hardening, the hardness of the white layer portion is low (Figure 2). This means that the strength is not uniform in the circumferential direction of the steel pipe, and that a region of low strength exists in the circumferential direction, albeit partially, and this exists over the entire length of the steel pipe. It is considered that there are.
したがって、このような状態で繰返しねじり応力が負荷
された場合には、白色層域で鋼管長さ方向に剪断応力が
かかり、この低強度域が起点となって割れが発生し、′
溶接部破断として溶接部の信頼性を著しく低下させるこ
とになる。Therefore, if repeated torsional stress is applied in such a state, shear stress will be applied in the length direction of the steel pipe in the white layer region, and cracks will occur starting from this low strength region.
The reliability of the weld will be significantly reduced as the weld will break.
そこで、本発明者らは、電縫鋼管の溶接中心部の白色層
で硬度が低下せず、円周方向に均一に所定の高硬度を具
備させることができる方策を見い出すべく鋭意研究を重
ねた。その結果、所定の材＝４
料特性を確保するべくＣ，Ｓｉ、Ｍｎ、Ｃｒ、Ｔｉ、Ｂ
等で成分調整し、特に適量のＣｕとＮｉの適量を同時添
加することにより、可能であることを見い出し、ここに
本発明をなしたものである。Therefore, the present inventors conducted extensive research in order to find a method that could uniformly provide a predetermined high hardness in the circumferential direction without reducing the hardness of the white layer at the weld center of the ERW steel pipe. . As a result, C, Si, Mn, Cr, Ti, B
We have discovered that this is possible by adjusting the ingredients, particularly by adding appropriate amounts of Cu and Ni at the same time, and have hereby accomplished the present invention.
すなわち、本発明に係る電縫鋼管用鋼は、Ｃ：０．１０
〜０．４．０％、Ｓｉ：０．２５％以下、Ｍｎ：０．３
０−１．００％、Ｃｒ：０．５０％以下、Ｔｊ：０．０
０５〜０．０５０％及びＢ：Ｑ、Ｑ ００５〜０゜００
５％を含み、更にＣｕ：０．０２−０．２０％及びＮｉ
：０．０２〜０．２０％を含み、Ｐ：０．０２０％以下
、Ｓ：０．０２０％以下で、残部がＦｅ及び不可避的不
純物よりなる鋼であり、該熱間圧延鋼帯をロール成形、
電気抵抗溶接して製造する電縫鋼管用で疲労特性の優れ
た鋼を要旨とするものである。また、前記化学成分にお
いてＣａを５〜１１００ｐｐ添加し、鋼中硫化物系介在
物の形態を制御することにより、−層信頼性の高い電縫
鋼管を得ることができる。That is, the steel for electric resistance welded steel pipes according to the present invention has a C: 0.10.
~0.4.0%, Si: 0.25% or less, Mn: 0.3
0-1.00%, Cr: 0.50% or less, Tj: 0.0
05~0.050% and B:Q,Q 005~0゜00
5%, further Cu:0.02-0.20% and Ni
: 0.02 to 0.20%, P: 0.020% or less, S: 0.020% or less, and the balance is Fe and inevitable impurities, and the hot rolled steel strip is rolled. molding,
The gist is a steel with excellent fatigue properties for use in electrical resistance welding for electric resistance welding steel pipes. Further, by adding 5 to 1100 pp of Ca to the chemical composition and controlling the form of sulfide inclusions in the steel, an electric resistance welded steel pipe with high -layer reliability can be obtained.
以下に本発明を更に詳細に説明する。The present invention will be explained in more detail below.
本発明によれば、疲労特性の優れた電縫鋼管用鋼が提供
されるが、これは、電縫溶接中心部の白色層が焼入れ処
理後に低硬度になるその機構を詳細に解明した結果、白
色層はＣ，Ｓｉ、Ｍｎの成分が低く、周りの部分に比べ
て加熱時のオーステナイト変態温度Ａｃ３点が高くなっ
ており、更に焼入れのための加熱に通常用いられる抵抗
加熱方式では加熱速度が非常に大きく、加熱速度が大き
いとＡｃ３点は上昇しく例えば、０．２０％Ｃ鋼の場合
、加熱速度２００℃／ｓｅｃでＡｃ３点は１７０℃上昇
する）、このため、白色層域はオーステナイトに未変態
のまま焼入れされ、十分な硬化が得られていないという
知見に基づき、構造用鋼として通常添加される成分Ｃ，
Ｓｉ、Ｍｎ、Ｃｒ、Ｔｉ、Ｂ、或いはＣａの元素に加え
て、Ｃｕ及びＮｉを同時添加し、これらの元素の添加量
を総合的に勘案して適正に配合したことによるものであ
る。According to the present invention, a steel for electric resistance welded pipes with excellent fatigue properties is provided, which is the result of elucidating in detail the mechanism by which the white layer at the center of the electric resistance welding becomes low in hardness after quenching. The white layer has low C, Si, and Mn components, and has a higher austenite transformation temperature Ac3 point during heating than the surrounding areas, and the heating rate is lower in the resistance heating method normally used for heating for quenching. (For example, in the case of 0.20% C steel, the Ac3 point increases by 170°C at a heating rate of 200°C/sec.) Therefore, the white layer region changes to austenite. Based on the knowledge that sufficient hardening is not achieved by quenching in an untransformed state, component C, which is usually added to structural steel,
This is because, in addition to the elements Si, Mn, Cr, Ti, B, or Ca, Cu and Ni are simultaneously added, and the amounts of these elements to be added are comprehensively taken into consideration and blended appropriately.
次に本発明の鋼における化学成分の限定理由製説明する
。Next, the reasons for limiting the chemical components in the steel of the present invention will be explained.
Ｃ：
Ｃは材料の強度及び焼入性を確保する元素であリ、その
ためには０１１０％以上を要する。しかし、０．４０％
を超えると造管時の溶接性に悪影響を及ぼすので好まし
くない。したがって、Ｃ量は０．１０〜０．４０％の範
囲とする。C: C is an element that ensures the strength and hardenability of the material, and for this purpose, 0.110% or more is required. However, 0.40%
Exceeding this is not preferable since it will have a negative effect on weldability during pipe making. Therefore, the amount of C is set in the range of 0.10 to 0.40%.
Ｓｌ：
Ｓｌは材料強度の確保に有効な元素であるが、０．２５
％を超えると靭性が劣化するので、Ｓｌ量は０．２５％
以下とする。Sl: Sl is an effective element for ensuring material strength, but 0.25
If it exceeds 0.25%, the toughness will deteriorate, so the amount of Sl should be 0.25%.
The following shall apply.
Ｍｎ： Ｍｎは強度確保及び焼入性の向上に必要な元素である。Mn: Mn is an element necessary to ensure strength and improve hardenability.
０．３０％未満では十分な焼入性が得られず、また１、
００％を超えると溶接性に悪影響を及ぼすので好ましく
ない。したがって、Ｍｎ量は０．３０〜１．００％の範
囲とする。If it is less than 0.30%, sufficient hardenability cannot be obtained;
If it exceeds 0.00%, it is not preferable because it will adversely affect weldability. Therefore, the amount of Mn is set in the range of 0.30 to 1.00%.
Ｃｒ：
Ｃｒは焼入性を向上せしめる元素であるが、０゜５０％
を超えて添加されると溶接時にペネトレーター欠陥を発
生し易くなるので、Ｃｒ量は０．５０％以下とする。Cr: Cr is an element that improves hardenability, but at 0°50%
If added in excess of Cr, penetrator defects are likely to occur during welding, so the amount of Cr is set to 0.50% or less.
Ｂ：
Ｂは焼入性を大幅に向上させる元素である。しかし、０
．０００５％未満では焼入性に効果がなく、また０、０
０５％を超えて添加しても介在物として存在し、清浄度
を悪くするので好ましくない。したがって、Ｂ量は０．
０００５〜０．００５％の範囲とする。B: B is an element that significantly improves hardenability. However, 0
．． If it is less than 0,005%, it has no effect on hardenability, and if it is less than 0,0
Even if it is added in an amount exceeding 0.5%, it is not preferable because it exists as inclusions and impairs cleanliness. Therefore, the amount of B is 0.
The range is 0.0005% to 0.005%.
Ｔｉ量：
Ｔｉは窒化物形成元素で、Ｂ添加による焼入性を安定且
つ効果的に行うために有効な元素である。Ti amount: Ti is a nitride-forming element and is an effective element for stably and effectively achieving hardenability by adding B.
しかし、０．００５％未満では窒化物の形成に不十分で
あり、また０、０５０％を超えて添加しても介在物とし
て存在し、逆に加工性に悪影響を及ぼすので好ましくな
い。したがって、Ｔｉ量は０゜００５〜０．０５０％の
範囲とする。However, if it is less than 0.005%, it is insufficient to form nitrides, and if it is added in excess of 0.050%, it will exist as inclusions, which will adversely affect workability, which is not preferable. Therefore, the amount of Ti is in the range of 0.005% to 0.050%.
Ｃｕ：
Ｃｕは偏析係数の小さい元素で、溶接中心部の白色層中
に残存してＡＣ３点を低下させるだけでなく、焼入性も
向上させる効果がある。しかし、０゜０２％未満ではそ
の効果が小さく、また０、２０％を超えて添加してもそ
の効果は飽和し、原価の＝７
上昇になるので好ましくない。したがって、Ｃｕ量は０
．０２〜０．２０％の範囲に限定する。Cu: Cu is an element with a small segregation coefficient, remains in the white layer at the center of the weld, and has the effect of not only lowering the AC3 point but also improving hardenability. However, if it is less than 0.02%, the effect will be small, and if it is added in excess of 0.20%, the effect will be saturated and the cost will increase by 7%, which is not preferable. Therefore, the amount of Cu is 0
．． It is limited to a range of 0.02 to 0.20%.
Ｎ１：
ＮｉはＣｕと同様、溶接中心部の白色層のＡｃ１１点を
低下させるだけでなく焼入性も向上させ、Ｃｕと同時添
加によりその効果が増長される効果を示す。しかし、０
．０２％未満ではその効果は不十分であり、また０、２
０％を超えて添加しても目的とする効果は飽和し原価の
上昇になるので好ましくない。したがって、Ｎｉ量は０
．０２〜０．２０％の範囲に限定する。N1: Like Cu, Ni not only lowers the Ac11 point of the white layer at the center of the weld, but also improves the hardenability, and this effect is enhanced by simultaneous addition with Cu. However, 0
．． If it is less than 0.02%, the effect is insufficient;
Adding more than 0% is not preferable because the desired effect will be saturated and the cost will increase. Therefore, the amount of Ni is 0
．． It is limited to a range of 0.02 to 0.20%.
Ｃａ：
Ｃａは硫化物の形態制御に有効で加工性の向上に寄与す
る元素であるので、必要に応じて添加することができる
。添加する場合、５ ｐｐｍ未満では形態制御効果が十
分でなく、また１１００ｐｐを超えると介在物量が多く
なり、延性、靭性が劣化するので、５〜１１００ｐｐの
範囲に限定する。Ca: Ca is an element that is effective in controlling the morphology of sulfides and contributes to improving workability, so it can be added as necessary. When added, if it is less than 5 ppm, the shape control effect will not be sufficient, and if it exceeds 1,100 ppm, the amount of inclusions will increase and ductility and toughness will deteriorate, so it is limited to a range of 5 to 1,100 ppm.
Ｐ ：
Ｐは靭性劣化をもたらすので、０．０２０％以下に規制
する。P: Since P causes deterioration of toughness, it is regulated to 0.020% or less.
Ｓ ：
Ｓは硫化物系介在物の主元素であって、加工性を悪化さ
せるので、０．０２０％以下に規制する。S: S is the main element of sulfide inclusions and deteriorates workability, so it is regulated to 0.020% or less.
次に本発明の実施例を示す。Next, examples of the present invention will be shown.
（実施例）
第１表に示す化学成分を有する鋼Ａ、Ｂ、Ｃを常法によ
り溶製、鋳造し、得られた鋳塊を熱間圧延し、更にスリ
ットコイルとした後、成形、溶接によりサイズ２２．２
ｍｍ（外径）Ｎ２．６ｍｍ（肉厚）に造管した。更に約
６５０℃の温度で焼鈍処理を実施した。(Example) Steels A, B, and C having the chemical components shown in Table 1 are melted and cast using conventional methods, and the resulting ingots are hot rolled and further made into slit coils, which are then formed and welded. Size 22.2
A tube with a diameter of N2.6 mm (outer diameter) and wall thickness was produced. Furthermore, an annealing treatment was performed at a temperature of about 650°C.
上記素管より１０００ｍｍ長さの試験片を採取し、その
直管部の両端をクランプして抵抗加熱方式により第２表
に示す加熱条件で加熱し、水焼入れした。A test piece with a length of 1000 mm was taken from the above-mentioned raw pipe, and both ends of the straight pipe portion were clamped and heated under the heating conditions shown in Table 2 using a resistance heating method, and water quenched.
前記条件にて得た溶接部断面の硬さ分布を第３図に示す
。同図より明らかなとおり、本発明鋼Ｂは比較鋼Ａに比
べて溶接中心部の白色層においても硬度が低下せず、パ
イプ円周方向の強度均一性が得られている。FIG. 3 shows the hardness distribution of the cross section of the welded part obtained under the above conditions. As is clear from the figure, the hardness of the steel B of the present invention does not decrease compared to the comparative steel A even in the white layer at the center of the weld, and strength uniformity in the circumferential direction of the pipe is obtained.
また、前記条件にて得たパイプについてねじり疲労試験
を行った結果を第４図に示す。同図より明らかなとおり
、本発明鋼Ｂは、前述のように溶接中心部の白色層にお
いて十分な硬度を有する結果、疲労試験においても溶接
部破断は認められず、優れた耐久性を示している。Further, FIG. 4 shows the results of a torsional fatigue test conducted on the pipe obtained under the above conditions. As is clear from the figure, inventive steel B has sufficient hardness in the white layer at the center of the weld as described above, and as a result, no weld fracture was observed in the fatigue test, demonstrating excellent durability. There is.
なお、更にＣａを５〜１００ ｐｐｍの範囲内で添加し
た本発明鋼Ｃについても、同様に優れた疲労特性が得ら
れることが確認された。In addition, it was confirmed that similarly excellent fatigue properties were obtained with the steel C of the present invention to which Ca was added in a range of 5 to 100 ppm.
［以下余白）
（発明の効果）
以上詳述したように、本発明によれば、スタビライザー
などの自動車足廻り部品等に適用される電縫鋼管に関し
て、溶接中心部の白色層における硬さ低下をなくすこと
ができるので、優れた疲労特性を具備でき、且つ溶接部
品質の信頼性が高い優れた疲労特性を有する電縫鋼管を
安定して製造できる。[Blank below] (Effects of the Invention) As detailed above, according to the present invention, the reduction in hardness in the white layer at the center of the weld can be reduced with respect to electric resistance welded steel pipes applied to automobile suspension parts such as stabilizers. Therefore, it is possible to stably manufacture an electric resistance welded steel pipe that has excellent fatigue properties and has high reliability in the quality of the welded part.
第１図は溶接部の断面の金属組織を示す写真、第２図及
び第３図は溶接部の硬さ分布を示す図、第４図はパイプ
のねじり疲労試験結果を示す図である。
特許出願人 株式会社神戸製鋼所
代理人弁理士 中 村 尚
（（ｏｏ＋ＡＨ） ＣFIG. 1 is a photograph showing the metal structure of a cross-section of a weld, FIGS. 2 and 3 are diagrams showing the hardness distribution of the weld, and FIG. 4 is a diagram showing the results of a torsional fatigue test of the pipe. Patent applicant Hisashi Nakamura ((oo+AH) C
Claims (2)
０％、Ｓｉ：０．２５％以下、Ｍｎ：０．３０〜１．０
０％、Ｃｒ：０．５０％以下、Ｔｉ：０．００５〜０．
０５０％及びＢ：０．０００５〜０．００５％を含み、
更にＣｕ：０．０２〜０．２０％及びＮｉ：０．０２〜
０．２０％を含み、Ｐ：０．０２０％以下、Ｓ：０．０
２０％以下で、残部がＦｅ及び不可避的不純物よりなる
鋼であり、該熱間圧延鋼帯をロール成形、電気抵抗溶接
して製造する電縫鋼管用で疲労特性の優れた鋼。(1) In weight% (the same applies hereinafter), C: 0.10 to 0.4
0%, Si: 0.25% or less, Mn: 0.30 to 1.0
0%, Cr: 0.50% or less, Ti: 0.005-0.
050% and B: 0.0005 to 0.005%,
Furthermore, Cu: 0.02 to 0.20% and Ni: 0.02 to
Contains 0.20%, P: 0.020% or less, S: 0.0
20% or less, the balance being Fe and unavoidable impurities, and is a steel with excellent fatigue properties for use in electric resistance welded steel pipes manufactured by roll forming and electric resistance welding the hot rolled steel strip.
て鋼中硫化物系介在物の形態を制御してなるものである
請求項１に記載の鋼。(2) The steel according to claim 1, wherein 5 to 100 ppm of Ca is further added to the steel to control the form of sulfide inclusions in the steel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15399288A JPH024944A (en) | 1988-06-22 | 1988-06-22 | Steel for electric-resistance weld steel tube having excellent fatigue characteristics |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15399288A JPH024944A (en) | 1988-06-22 | 1988-06-22 | Steel for electric-resistance weld steel tube having excellent fatigue characteristics |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH024944A true JPH024944A (en) | 1990-01-09 |
| JPH0576533B2 JPH0576533B2 (en) | 1993-10-22 |
Family
ID=15574549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15399288A Granted JPH024944A (en) | 1988-06-22 | 1988-06-22 | Steel for electric-resistance weld steel tube having excellent fatigue characteristics |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH024944A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008095156A (en) * | 2006-10-13 | 2008-04-24 | Nisshin Steel Co Ltd | Method for manufacturing hollow stabilizer with excellent delayed fracture resistance |
| JP2008255397A (en) * | 2007-04-03 | 2008-10-23 | Nisshin Steel Co Ltd | Method for producing electric resistance welded tube for hollow stabilizer |
| WO2010092992A1 (en) * | 2009-02-12 | 2010-08-19 | 日本発條株式会社 | Steel for high-strength vehicle stabilizer with excellent corrosion resistance and low-temperature toughness, and process for the production of same, and stabilizer |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58167750A (en) * | 1982-03-29 | 1983-10-04 | Kobe Steel Ltd | High strength steel plate excellent in elongation flange property |
| JPS60230960A (en) * | 1984-04-27 | 1985-11-16 | Daido Steel Co Ltd | Steel for cold forging |
| JPS62238326A (en) * | 1986-04-08 | 1987-10-19 | Kobe Steel Ltd | Manufacture of nontemper steel for low temperature superior in stopping characteristic for brittle crack propagation |
-
1988
- 1988-06-22 JP JP15399288A patent/JPH024944A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58167750A (en) * | 1982-03-29 | 1983-10-04 | Kobe Steel Ltd | High strength steel plate excellent in elongation flange property |
| JPS60230960A (en) * | 1984-04-27 | 1985-11-16 | Daido Steel Co Ltd | Steel for cold forging |
| JPS62238326A (en) * | 1986-04-08 | 1987-10-19 | Kobe Steel Ltd | Manufacture of nontemper steel for low temperature superior in stopping characteristic for brittle crack propagation |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008095156A (en) * | 2006-10-13 | 2008-04-24 | Nisshin Steel Co Ltd | Method for manufacturing hollow stabilizer with excellent delayed fracture resistance |
| JP2008255397A (en) * | 2007-04-03 | 2008-10-23 | Nisshin Steel Co Ltd | Method for producing electric resistance welded tube for hollow stabilizer |
| WO2010092992A1 (en) * | 2009-02-12 | 2010-08-19 | 日本発條株式会社 | Steel for high-strength vehicle stabilizer with excellent corrosion resistance and low-temperature toughness, and process for the production of same, and stabilizer |
| JP2010185109A (en) * | 2009-02-12 | 2010-08-26 | Jfe Bars & Shapes Corp | Steel superior in corrosion resistance and low-temperature toughness for high-strength stabilizer for vehicle, manufacturing method therefor and stabilizer |
| US8206521B2 (en) | 2009-02-12 | 2012-06-26 | Nhk Spring Co., Ltd. | High-strength stabilizer steel for vehicles having excellent corrosion resistance and low-temperature toughness, method of producing the same, and stabilizer |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0576533B2 (en) | 1993-10-22 |
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