JPH0987737A - Method for locally softening steel material - Google Patents
Method for locally softening steel materialInfo
- Publication number
- JPH0987737A JPH0987737A JP25264895A JP25264895A JPH0987737A JP H0987737 A JPH0987737 A JP H0987737A JP 25264895 A JP25264895 A JP 25264895A JP 25264895 A JP25264895 A JP 25264895A JP H0987737 A JPH0987737 A JP H0987737A
- Authority
- JP
- Japan
- Prior art keywords
- steel material
- strength
- steel
- arc
- formability
- 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.)
- Pending
Links
Landscapes
- Laser Beam Processing (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、鋼材の局部的な軟
化方法に関し、具体的には、鋼材に対し高強度と高成形
性が要求される場合に、成形性が必要とされる部分を局
部的に軟化させてその部分の変形特性を改善する鋼材の
局部軟化方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for locally softening a steel material. Specifically, when high strength and high formability are required for the steel material, the portion requiring the formability is selected. The present invention relates to a method for locally softening a steel material by locally softening it to improve the deformation characteristics of that portion.
【０００２】[0002]
【従来の技術】鉄鋼を用いた構造物において軽量化や高
強度化が望まれる場合、通常、高強度の鋼材（例えば、
高強度鋼板）が用いられる。しかし、鋼板のように、プ
レス成形等により成形加工が施される場合は、高強度鋼
板は延性が小さいために厳しい成形加工に耐えられな
い。また、高強度鋼板は降伏応力が高いのでスプリング
バックが大きく、形状凍結性に劣るという問題もあっ
た。このような理由から、鋼材においては高強度と高成
形性を両立させるのが難しく、高強度鋼板等の使用にも
限界があった。2. Description of the Related Art When it is desired to reduce the weight and increase the strength of a structure made of steel, a high strength steel material (for example,
High strength steel plate) is used. However, when a forming process is performed by press forming or the like like a steel plate, the high-strength steel plate cannot withstand severe forming process because of its low ductility. Further, since the high-strength steel sheet has a high yield stress, there is a problem that springback is large and shape fixability is poor. For these reasons, it is difficult to achieve both high strength and high formability in steel materials, and there is a limit to the use of high strength steel sheets and the like.
【０００３】この対策として、例えば自動車の分野で
は、成形後に行われる電着塗装時の焼き付け過程で硬化
する焼き付け硬化型鋼板が使用されている。また、特開
平６−７３４３８号公報には、加工時には優れた加工特
性を有し、加工完了後に強度が必要とされる部分にレー
ザなどのエネルギービームを照射して焼き入れ硬化さ
せ、高強度化して使用することができる高加工性鋼板が
開示されている。As a countermeasure against this, for example, in the field of automobiles, a bake hardening type steel plate is used which is hardened in the baking process at the time of electrodeposition coating performed after forming. Further, in Japanese Patent Laid-Open No. 6-73438, a portion having excellent working characteristics at the time of working and requiring strength after completion of working is irradiated with an energy beam such as a laser to be quenched and hardened to increase strength. A high workability steel sheet that can be used as a steel sheet is disclosed.
【０００４】[0004]
【発明が解決しようとする課題】上記の焼き付け硬化型
鋼板は、硬化後の強度が高々４０kg／mm2 程度であり、
それ以上の強度が必要とされる場合には強度が不足す
る。また、特開平６−７３４３８号公報に記載された加
工後に部分的に焼き入れを施して使用する高加工性鋼板
は、構造物に要求される強度が高くなるほど大きな面積
に焼き入れ処理を施す必要があり、焼き入れ処理に要す
るコストと時間が増大する。さらに、その場合、鋼板の
熱による変形が大きくなるという問題もある。The above-mentioned bake hardenable steel sheet has a strength after hardening of at most about 40 kg / mm 2 .
When the higher strength is required, the strength is insufficient. Further, in the high workability steel sheet described in JP-A-6-73438, which is used after being partially quenched, it is necessary to perform a quenching treatment on a larger area as the strength required for the structure increases. Therefore, the cost and time required for the quenching process increase. Further, in that case, there is also a problem that the deformation of the steel sheet due to heat increases.
【０００５】一方、高強度鋼材を用いれば必要とされる
強度は確保されるが、厳しい加工が施される部分では破
断等が生じる場合があり、成形性に問題がある。On the other hand, if a high strength steel material is used, the required strength can be secured, but breakage may occur at the portion subjected to severe processing, and there is a problem in formability.
【０００６】本発明は、このような問題を解決し、鋼材
における高強度と高成形性を両立させ得る方法を提供す
ることを課題としてなされたものである。An object of the present invention is to solve the above problems and to provide a method capable of achieving both high strength and high formability in a steel material.
【０００７】[0007]
【課題を解決するための手段】上述したように、従来、
鋼材において高強度と高成形性を両立させるために採ら
れていた手段は、鋼材を成形した後、加熱により強化す
るという考え方に基づくものであった。As described above, as described above,
The means adopted to achieve both high strength and high formability in steel materials was based on the idea that after steel materials are formed, they are strengthened by heating.
【０００８】本発明者らは、このような考え方とは逆
に、高強度鋼材を用い、厳しい成形加工を受ける部分の
成形性を局部的に向上させることによって、成形性と最
終製品の強度を両立させることが可能になるとの観点か
ら、鋼材の局部的軟化方法について検討した。その結
果、加工性が要求される部位を酸素を含有するガスをシ
ールドガスとして用いて加熱し、一度溶融させることに
よって、その部分が軟化し、延性が向上することを見い
だした。Contrary to such an idea, the inventors of the present invention use high-strength steel material and locally improve the formability of a portion which is subjected to severe forming work, thereby improving the formability and the strength of the final product. From the viewpoint that it is possible to achieve both at the same time, the local softening method of steel was examined. As a result, they have found that by heating a portion requiring workability using a gas containing oxygen as a shield gas and melting it once, the portion is softened and ductility is improved.
【０００９】本発明はこの知見に基づきなされたもの
で、その要旨は下記の鋼材の局部軟化方法にある。The present invention has been made based on this finding, and the gist thereof is the following method for locally softening a steel material.
【００１０】高強度の鋼材の局部軟化に際して、酸素を
５体積％以上含有するガスをシールドガスとして用いて
アークまたはレーザビームを照射することを特徴とする
鋼材の局部軟化方法。A method of locally softening a steel material, which comprises irradiating an arc or a laser beam using a gas containing 5% by volume or more of oxygen as a shielding gas when locally softening a high strength steel material.
【００１１】[0011]
【発明の実施の形態】以下、本発明の鋼材の局部軟化方
法について詳細に説明する。BEST MODE FOR CARRYING OUT THE INVENTION The method for locally softening a steel material according to the present invention will be described in detail below.
【００１２】本発明方法では、上記のように、高強度の
鋼材を対象とするが、これは以下の理由によるものであ
る。In the method of the present invention, as described above, high strength steel materials are targeted, but this is due to the following reasons.
【００１３】高強度鋼材には、強度を確保するために、
Ｃ、Ｓｉ、Ｍｎ、Ｐ、Ｔｉ、Ｎｂ、Ｂ等の合金元素のう
ちの一種以上の元素が添加されている。これらの合金元
素の中でも、Ｃ、Ｓｉ、Ｍｎは最も一般的に鋼材の強化
に使用される元素である。鋼材の強化元素であるこれら
Ｃ、ＳｉおよびＭｎは、いずれも酸素との親和力が強い
元素で、これらの元素を含む溶鋼中に酸素が存在すると
脱酸反応が起こり、これらの元素は酸化物として溶鋼か
ら分離する。その結果、凝固後の鋼中に含まれるＣ、Ｓ
ｉおよびＭｎの含有量が減少し、降伏応力と破断強度が
低下するとともに、延性が向上する。In order to secure strength, high strength steel material
One or more elements of alloying elements such as C, Si, Mn, P, Ti, Nb and B are added. Among these alloy elements, C, Si and Mn are the elements most commonly used for strengthening steel materials. These C, Si, and Mn, which are strengthening elements of steel materials, are all elements having a strong affinity with oxygen, and when oxygen is present in molten steel containing these elements, a deoxidation reaction occurs, and these elements are converted into oxides. Separate from molten steel. As a result, C and S contained in the steel after solidification
The contents of i and Mn decrease, yield stress and fracture strength decrease, and ductility improves.
【００１４】本発明方法は、上記のような母材中に含ま
れる強化元素の脱酸反応を利用して加工性が要求される
部位を軟化する方法である。従って、本発明方法が適用
される鋼材は高強度鋼材であることが必要である。The method of the present invention is a method of softening a portion requiring workability by utilizing the deoxidation reaction of the reinforcing element contained in the base material as described above. Therefore, the steel material to which the method of the present invention is applied must be a high-strength steel material.
【００１５】高強度鋼材の成分については特に限定しな
い。これは、高強度鋼材には前述したようにＣ、Ｓｉお
よびＭｎの少なくとも１種が必ず添加されており、この
ような高強度鋼材が対象として用いられる限り本発明方
法の効果が発揮されるからである。しかし、Ｃ、Ｓｉお
よびＭｎの含有量が多いほど、本発明方法を適用した場
合の軟化効果が大きいので、高強度鋼材は、重量％で、
Ｃが0.05％以上、Ｓｉが 0.2％以上、およびＭｎが 0.5
％以上の三条件のうちの少なくとも一つの条件を満たす
ものであることが望ましい。The components of the high-strength steel material are not particularly limited. This is because at least one of C, Si and Mn is always added to the high strength steel material, and the effect of the method of the present invention is exhibited as long as such high strength steel material is used as a target. Is. However, the higher the content of C, Si, and Mn, the greater the softening effect when the method of the present invention is applied.
C is 0.05% or more, Si is 0.2% or more, and Mn is 0.5.
It is desirable to satisfy at least one of the above three conditions.
【００１６】また、本発明方法は、冷延鋼板、熱延鋼
板、鋼管、棒鋼、厚板など、鋼材の種類によらずいずれ
のものにも適用できる。The method of the present invention can be applied to any of cold-rolled steel sheets, hot-rolled steel sheets, steel pipes, steel bars, thick plates and the like regardless of the type of steel material.
【００１７】本発明方法を適用して高強度鋼材の加工性
が要求される部位を軟化するに際し、熱源にはアークま
たはレーザを用いる。アークとしては、タングステンな
どの非消耗電極を用いたＴＩＧアークや、プラズマアー
クを用いることができる。さらに、アーク照射後にビー
ド研削を施す必要はあるが、消耗電極式のＭＡＧアーク
も適用可能である。また、レーザとしては、ＣＯ2 レー
ザやＹＡＧレーザ等を用いることができる。これらのア
ークまたはレーザビームを加工性が要求される部位に照
射してやればよい。When the method of the present invention is applied to soften the portion of the high-strength steel material requiring workability, an arc or laser is used as a heat source. As the arc, a TIG arc using a non-consumable electrode such as tungsten or a plasma arc can be used. Further, it is necessary to perform bead grinding after the arc irradiation, but a consumable electrode type MAG arc is also applicable. A CO 2 laser, a YAG laser, or the like can be used as the laser. It suffices to irradiate a portion requiring workability with these arcs or laser beams.
【００１８】アークまたはレーザビームを照射する際、
シールドガスには５体積％以上の酸素が含まれているこ
とが必要である。酸素の含有量が５体積％未満では、ア
ークやレーザビームを照射した部分の軟化効果が得られ
ないばかりか、焼き入れ効果により硬化し、成形性が母
材よりも劣ることになる。When irradiating with an arc or a laser beam,
It is necessary that the shield gas contains 5% by volume or more of oxygen. If the oxygen content is less than 5% by volume, not only the softening effect of the portion irradiated with the arc or the laser beam cannot be obtained, but also hardening occurs due to the quenching effect, and the formability becomes inferior to that of the base material.
【００１９】シールドガスに含まれる酸素の含有量が多
いほど軟化効果が大きく、１００体積％（純酸素）でも
よい。しかし、酸素濃度が高くなるほどアークやレーザ
の照射部の表面に厚い酸化膜（酸化スケール）が生成し
やすいので、表面の高い清浄度が要求される場合は、酸
素濃度の上限を６０体積％とするのが好ましい。The larger the oxygen content in the shield gas, the greater the softening effect, and it may be 100% by volume (pure oxygen). However, as the oxygen concentration becomes higher, a thick oxide film (oxide scale) is more likely to be formed on the surface of the arc or laser irradiation portion. Therefore, when high surface cleanliness is required, the upper limit of the oxygen concentration is 60% by volume. Preferably.
【００２０】シールドガスに含有させる酸素以外の成分
としては、アルゴンやヘリウム等の不活性ガス、炭酸ガ
ス、および窒素ガスを用いることができる。なお、アー
ク照射の場合は電極を、レーザビームを照射する場合は
集光レンズやミラーをそれぞれ酸化から保護するため
に、純アルゴンなど、酸素を含まないガスをシールドガ
ス（センターシールド）として用いる場合がある。その
ような場合は、二重ノズルの外側ノズルや、補助ノズル
を用いて酸素を含有させたシールドガス（サイドシール
ド）を流すことにより、本発明方法による軟化効果が得
られる。この場合、センターシールドガスとサイドシー
ルドガスが完全に混合したと仮定して計算したガス組成
が、本発明方法で規定する酸素含有量が５体積％以上と
いう条件を満たしていればよい。As a component other than oxygen contained in the shield gas, an inert gas such as argon or helium, carbon dioxide gas, and nitrogen gas can be used. In addition, when arc-irradiating the electrodes and when irradiating the laser beam, when using a gas containing no oxygen such as pure argon as a shield gas (center shield) to protect the condenser lens and mirror from oxidation. There is. In such a case, the softening effect according to the method of the present invention can be obtained by flowing an oxygen-containing shield gas (side shield) using an outer nozzle of the double nozzle or an auxiliary nozzle. In this case, the gas composition calculated on the assumption that the center shield gas and the side shield gas are completely mixed has only to satisfy the condition that the oxygen content specified by the method of the present invention is 5% by volume or more.
【００２１】図１は本発明方法の実施状況を模式的に示
す図である。図中の符号１は熱源としてのアークまたは
レーザを表し、２は酸素を所定量含有させたシールドガ
スである。また、３はすでに形成された軟化部である。
この図に示すように、酸素を含有するシールドガス雰囲
気中で、アークやレーザを照射し、加熱、溶融しつつ、
加工性が要求される部位を走査することにより、軟化部
３を形成する。FIG. 1 is a diagram schematically showing an implementation situation of the method of the present invention. Reference numeral 1 in the figure represents an arc or laser as a heat source, and 2 represents a shield gas containing a predetermined amount of oxygen. Further, 3 is a softened portion that has already been formed.
As shown in this figure, in a shield gas atmosphere containing oxygen, while irradiating with an arc or laser, heating, melting,
The softened portion 3 is formed by scanning the portion where workability is required.
【００２２】上記のように、高強度鋼材に対して本発明
方法を適用すれば、成形加工を受ける部分の成形性を局
部的に向上させることができるので、高強度と良好な成
形性とを両立させることが可能になる。この方法は、特
に、鋼材に対して高強度と高成形性が要求される自動車
等の分野での利用に好適であり、高強度鋼材の適用範囲
を大幅に拡大することができる。As described above, when the method of the present invention is applied to a high-strength steel material, the formability of the portion subjected to the forming process can be locally improved, so that high strength and good formability can be obtained. It becomes possible to make them compatible. This method is particularly suitable for use in fields such as automobiles where high strength and high formability are required for steel materials, and the range of application of high strength steel materials can be greatly expanded.
【００２３】[0023]
（実施例１）表１に示す化学成分および機械的性質を有
する板厚 2.0mmの熱延鋼板（高強度鋼板）を供試鋼板と
して、これにプラズマアークを照射し、アーク照射部の
特性評価を行った。(Example 1) A hot-rolled steel sheet (high-strength steel sheet) having a thickness of 2.0 mm having the chemical composition and mechanical properties shown in Table 1 was used as a test steel sheet, which was irradiated with a plasma arc to evaluate the characteristics of the arc irradiation part. I went.
【００２４】プラズマアークを照射する際、電極の酸化
損耗を防止するために二重ノズルを使用し、電極周囲に
流れるプラズマガスにはアルゴンを用い、その外側から
サイドシールドガスとしてアルゴンと酸素の混合ガスを
流した。表２にプラズマアークの照射条件を示す。この
条件では、幅が約 8mmの照射部が得られるので、電源を
適宜走査して供試鋼板上に幅50mm、長さ 100mmの照射部
を形成した。When irradiating a plasma arc, a double nozzle is used to prevent oxidative wear of the electrode, argon is used as the plasma gas flowing around the electrode, and argon and oxygen are mixed from the outside as a side shield gas. The gas was flushed. Table 2 shows the plasma arc irradiation conditions. Under this condition, an irradiation part with a width of about 8 mm was obtained, so the power supply was appropriately scanned to form an irradiation part with a width of 50 mm and a length of 100 mm on the test steel plate.
【００２５】アーク照射部の特性評価は引張り試験によ
って行った。試験片は JIS−Z2241に規定される５号引
張り試験片であり、前記の幅50mm、長さ 100mmの照射部
が引張り試験片の平行部に含まれるように供試鋼板から
採取した。The characteristics of the arc irradiated part were evaluated by a tensile test. The test piece was a No. 5 tensile test piece specified in JIS-Z2241 and was sampled from the test steel sheet so that the irradiation part having the width of 50 mm and the length of 100 mm was included in the parallel part of the tensile test piece.
【００２６】表３に評価結果を示す。なお、表３の鋼板
の欄のＮｏ．は表１のＮｏ．に対応する。この結果から
明らかなように、試験番号１、２および６の比較例で
は、シールドガス組成（プラズマガスとサイドシールド
ガスの混合ガスの組成）が本発明方法で規定する範囲か
ら外れているために、母材に比べてプラズマアーク照射
部の強度（降伏点YPおよび引張強さTS）が高く、延性
（EL）が低かった。これに対して、本発明例（試験番号
３、４、５、７および８）では、プラズマアークの照射
により、母材に比べて強度が低下し、延性が向上した。Table 3 shows the evaluation results. In addition, No. in the column of steel plate in Table 3 Is No. in Table 1. Corresponding to. As is clear from this result, in the comparative examples of Test Nos. 1, 2 and 6, the shield gas composition (the composition of the mixed gas of the plasma gas and the side shield gas) is out of the range defined by the method of the present invention. , The strength of the plasma arc irradiated part (yield point YP and tensile strength TS) was higher and the ductility (EL) was lower than the base metal. On the other hand, in the inventive examples (Test Nos. 3, 4, 5, 7 and 8), the plasma arc irradiation reduced the strength as compared with the base material and improved the ductility.
【００２７】（実施例２）表１に示した供試鋼板にレー
ザビームを照射し、実施例１の場合と同様に照射部の特
性評価を行った。(Example 2) The test steel sheets shown in Table 1 were irradiated with a laser beam, and the characteristics of the irradiated part were evaluated in the same manner as in Example 1.
【００２８】レーザビーム照射の際、シールドガスとし
てアルゴンと酸素の混合ガスをレーザビームと同軸に流
した。表４にレーザビームの照射条件を示す。この条件
では、幅が約 5mmの照射部が得られるが、実施例１の場
合と同様に、供試鋼板上に幅50mm、長さ 100mmの照射部
を形成した。At the time of laser beam irradiation, a mixed gas of argon and oxygen was made to flow coaxially with the laser beam as a shield gas. Table 4 shows the irradiation conditions of the laser beam. Under this condition, an irradiation part having a width of about 5 mm can be obtained, but as in the case of Example 1, an irradiation part having a width of 50 mm and a length of 100 mm was formed on the test steel plate.
【００２９】表５に評価結果を示す。試験番号１、２お
よび７の比較例では、はシールドガス組成が本発明方法
で定める範囲から外れているために、母材に比べてレー
ザビーム照射部の強度が高く、延性は低かった。これに
対して、本発明例（試験番号３、４、５、６、８および
９）では、レーザビームの照射により母材に比べて強度
が低下し、延性が優れる結果となった。Table 5 shows the evaluation results. In Comparative Examples of Test Nos. 1, 2 and 7, since the shield gas composition was out of the range defined by the method of the present invention, the strength of the laser beam irradiation portion was higher and the ductility was lower than that of the base material. On the other hand, in the examples of the present invention (Test Nos. 3, 4, 5, 6, 8 and 9), the strength was lowered by the irradiation of the laser beam as compared with the base material, and the ductility was excellent.
【００３０】[0030]
【表１】 [Table 1]
【００３１】[0031]
【表２】 [Table 2]
【００３２】[0032]
【表３】 [Table 3]
【００３３】[0033]
【表４】 [Table 4]
【００３４】[0034]
【表５】 [Table 5]
【００３５】[0035]
【発明の効果】本発明方法によれば、鋼材の成形性が必
要な部分を局部的に軟化し、成形性を向上させることが
可能であり、従来成形性が悪いために使用することが困
難であった高強度鋼材の適用範囲を大きく拡大すること
ができる。EFFECTS OF THE INVENTION According to the method of the present invention, it is possible to locally soften the portion of the steel material that requires formability and improve the formability, and it is difficult to use because the conventional formability is poor. The range of application of high-strength steel materials, which was previously described, can be greatly expanded.
【図１】本発明方法の実施状況を模式的に示す図であ
る。FIG. 1 is a diagram schematically showing an implementation situation of a method of the present invention.
【符号の説明】 １：レーザまたはアーク ２：シールドガス ３：軟化部 ４：鋼板[Explanation of Codes] 1: Laser or arc 2: Shielding gas 3: Softening part 4: Steel plate
Claims (1)
５体積％以上含有するガスをシールドガスとして用いて
アークまたはレーザビームを照射することを特徴とする
鋼材の局部軟化方法。1. A method of locally softening a steel material, which comprises irradiating an arc or a laser beam using a gas containing 5% by volume or more of oxygen as a shield gas when locally softening a high strength steel material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25264895A JPH0987737A (en) | 1995-09-29 | 1995-09-29 | Method for locally softening steel material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP25264895A JPH0987737A (en) | 1995-09-29 | 1995-09-29 | Method for locally softening steel material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0987737A true JPH0987737A (en) | 1997-03-31 |
Family
ID=17240283
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP25264895A Pending JPH0987737A (en) | 1995-09-29 | 1995-09-29 | Method for locally softening steel material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0987737A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102004023579A1 (en) * | 2004-05-13 | 2005-12-15 | Adam Opel Ag | Process for heat treatment of a stainless steel joint part involving heat treatment of a partial region of the part with resultant softening of the steel useful in automobile construction, especially for strengthening of automobile bodies |
| CN109182679A (en) * | 2018-09-20 | 2019-01-11 | 浙江工业大学 | A kind of laser instantaneous annealing softening method |
| WO2020049344A1 (en) | 2018-09-07 | 2020-03-12 | Arcelormittal | Method for improving the formability of steel blanks |
| US20220143760A1 (en) * | 2019-03-26 | 2022-05-12 | Nippon Steel Corporation | Steel sheet and member |
-
1995
- 1995-09-29 JP JP25264895A patent/JPH0987737A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102004023579A1 (en) * | 2004-05-13 | 2005-12-15 | Adam Opel Ag | Process for heat treatment of a stainless steel joint part involving heat treatment of a partial region of the part with resultant softening of the steel useful in automobile construction, especially for strengthening of automobile bodies |
| DE102004023579B4 (en) * | 2004-05-13 | 2014-04-03 | GM Global Technology Operations LLC (n. d. Ges. d. Staates Delaware) | Process for the heat treatment of a joining part made of high-strength steel |
| WO2020049344A1 (en) | 2018-09-07 | 2020-03-12 | Arcelormittal | Method for improving the formability of steel blanks |
| WO2020049428A1 (en) | 2018-09-07 | 2020-03-12 | Arcelormittal | Method for improving the formability of steel blanks |
| CN112639140A (en) * | 2018-09-07 | 2021-04-09 | 安赛乐米塔尔公司 | Method for improving the formability of a steel billet |
| CN109182679A (en) * | 2018-09-20 | 2019-01-11 | 浙江工业大学 | A kind of laser instantaneous annealing softening method |
| US20220143760A1 (en) * | 2019-03-26 | 2022-05-12 | Nippon Steel Corporation | Steel sheet and member |
| US11826857B2 (en) * | 2019-03-26 | 2023-11-28 | Nippon Steel Corporation | Steel sheet and member |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP2942143A1 (en) | Methods for joining two blanks and blanks and products obtained | |
| EP4116455A1 (en) | Resistance spot welding method and manufacturing method for resistance spot welded joint | |
| US11919105B2 (en) | Method for welding pretreatment of coated steel sheets | |
| EP3736076B1 (en) | Resistance spot welding method, and method for producing resistance-spot-welded joint | |
| US20220258283A1 (en) | Method for producing a coated tailored welded blank by means of laser-beam welding or hybrid laser/gas-metal-arc welding and filler wire and use thereof for this purpose | |
| JPH0987737A (en) | Method for locally softening steel material | |
| JP6448844B1 (en) | Welding method | |
| JP2001239367A (en) | Gas shielded arc welding method | |
| JP3407668B2 (en) | Shipbuilding steel plate with excellent laser weldability | |
| CN115175781A (en) | Method for welding coated steel sheets | |
| JPH11104838A (en) | Welding joint for structural steel excellent in fatigue strength | |
| JPH08309428A (en) | Production of welded steel tube | |
| JP2979030B2 (en) | Steel sheet excellent in curability and formability by high energy density beam irradiation and method for producing the same | |
| JP4192576B2 (en) | Martensitic stainless steel sheet | |
| EP1340831B1 (en) | Welding steel for enhancing welded joint strength | |
| JPS60162758A (en) | High-toughness steel for welded structure having very large thickness | |
| JP2000015353A (en) | Welded joining metallic plate excellent in press formability and production thereof | |
| JPH09201688A (en) | Manufacture of welded steel tube excellent in strength in weld zone | |
| JPH07171679A (en) | Welded joint for structural steel excellent in fatigue resistance | |
| JPH09253860A (en) | Tig welding method of high tensile steel and solid wire for tig welding | |
| JP2004249353A (en) | Steel wire for carbon dioxide gas shielded arc welding, and welding method using the same | |
| KR20100050038A (en) | Welding method of high manganese steel using welding wire for austenite stainless steel | |
| JPH09122957A (en) | Filler material for laser beam welding of martensitic stainless steel | |
| JPH06104878B2 (en) | High-strength cold-rolled steel sheet excellent in butt weldability and chemical conversion treatability and method for producing the same | |
| JPH05148582A (en) | High tensile strength steel plate for electron beam welding |