JP2743699B2 - Laser welding method - Google Patents
Laser welding methodInfo
- Publication number
- JP2743699B2 JP2743699B2 JP4102904A JP10290492A JP2743699B2 JP 2743699 B2 JP2743699 B2 JP 2743699B2 JP 4102904 A JP4102904 A JP 4102904A JP 10290492 A JP10290492 A JP 10290492A JP 2743699 B2 JP2743699 B2 JP 2743699B2
- Authority
- JP
- Japan
- Prior art keywords
- base material
- welding
- electrode
- joint
- plasma
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Laser Beam Processing (AREA)
- Lasers (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、溶接継手の形状及び性
能の向上を図ったレーザ溶接方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser welding method for improving the shape and performance of a weld joint.
【０００２】[0002]
【従来の技術】一般に、薄板のレーザ溶接では溶接ビー
ド幅が非常に狭くなる。例えば図６に示すようにビーム
入側である母材表側は１mm程度、裏側は０．５mm程度で
ある。このため、開先ギャップの許容量を０．２mm，ビ
ーム照射精度を開先中心に対して±０．１mmにおさえな
ければならず溶接精度が厳しい。また、溶接継手の性能
の面からは、鋼板母材の伸びが４７％に対して、継手の
伸びは２５％程度であり、継手性能の低下がみられる。
以上のように薄板のレーザ溶接では、溶接精度を厳しく
保つ必要があることと、継手性能が低下するという２つ
の問題があり、この問題の解決策として、従来２つの方
法があった。その一つは、図７に示すように母材１，２
の突合せ部３の直下に反射板４を置き、キーホールを貫
通するレーザビーム１０の一部を反射板４によって反射
させ、この反射ビーム１１により突合せ部３の下部を加
熱する方法である。この方法によると、反射ビーム１１
により突合せ部３の下部を加熱するため、溶込みが促進
され、裏ビードの形状が良くなり、裏ビード幅が拡大す
る。その結果、開先精度を緩和することができ、また継
手の性質を改善できるので継手性能が向上する。もう一
つは、図８に示すように突合せ部３の下部をＴＩＧアー
ク１２で加熱する方法であり、前者の方法とほぼ同様の
効果がある。2. Description of the Related Art Generally, in laser welding of a thin plate, the width of a weld bead becomes very narrow. For example, as shown in FIG. 6, the front side of the base material which is the beam entrance side is about 1 mm, and the back side is about 0.5 mm. For this reason, the tolerance of the groove gap must be limited to 0.2 mm, and the beam irradiation accuracy must be limited to ± 0.1 mm with respect to the center of the groove. Further, from the viewpoint of the performance of the welded joint, the elongation of the joint is about 25% while the elongation of the base material of the steel sheet is 47%, and the joint performance is reduced.
As described above, in laser welding of thin plates, there are two problems that welding accuracy must be strictly maintained and joint performance is deteriorated. Conventionally, there are two methods for solving this problem. One of them is the base materials 1, 2 as shown in FIG.
In this method, a reflecting plate 4 is placed immediately below the butting portion 3, a part of the laser beam 10 penetrating the keyhole is reflected by the reflecting plate 4, and the lower portion of the butting portion 3 is heated by the reflected beam 11. According to this method, the reflected beam 11
As a result, the lower portion of the butted portion 3 is heated, so that penetration is promoted, the shape of the back bead is improved, and the width of the back bead is increased. As a result, the groove accuracy can be reduced, and the properties of the joint can be improved, so that the joint performance can be improved. The other is a method of heating the lower part of the butting portion 3 with the TIG arc 12 as shown in FIG. 8, and has substantially the same effect as the former method.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記の
従来法には次のような問題点があった。 図７に示す方法では、母材を溶かした溶鋼のスプラッ
シュが反射板上に付着し、次第にビームの反射率が低下
する。したがって、ビームの反射量が減少するため、裏
ビード幅を拡大し、継手性能を向上させる効果が低減
し、また反射板の寿命も短い。 板厚が大になったり、溶接速度が高速になると、母材
を貫通するビーム量が減少するので、上記効果が低減す
る。 図８に示す方法では、と同様にスプラッシュがＴＩ
Ｇ電極に付着し、アークが不安定になる。高速溶接の場
合もアークの不安定化をまねく。 よって、いずれの方法も上記効果を持続することが難し
く、数回の繰り返し使用で効果が失われるものであっ
た。However, the above-mentioned conventional method has the following problems. In the method shown in FIG. 7, the splash of molten steel in which the base material is melted adheres to the reflecting plate, and the beam reflectance gradually decreases. Therefore, since the amount of beam reflection is reduced, the width of the back bead is increased, the effect of improving the joint performance is reduced, and the life of the reflector is short. When the plate thickness is increased or the welding speed is increased, the amount of the beam penetrating through the base material is reduced, so that the above effect is reduced. In the method shown in FIG. 8, the splash is TI
The arc adheres to the G electrode and the arc becomes unstable. Arc instability also occurs in high-speed welding. Therefore, it is difficult for any of the methods to maintain the above effects, and the effects are lost after repeated use several times.
【０００４】本発明は、上記のような課題を解決するた
めになされたもので、溶接継手の形状と性能を向上させ
るとともに、この効果を永く保持できるレーザ溶接方法
を得ることを目的とする。[0004] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the shape and performance of a welded joint and to obtain a laser welding method capable of maintaining this effect for a long time.
【０００５】[0005]
【課題を解決するための手段】上記の目的を達成するた
め、本発明に係るレーザ溶接方法は、キーホール溶接の
レーザ溶接において、母材の裏側に電極を配置し、溶接
中、母材と電極間に直流もしくは交流の電圧を印加して
母材裏側でプラズマを発生させ、このプラズマにより母
材裏面を加熱することとしたものである。In order to achieve the above-mentioned object, a laser welding method according to the present invention comprises a step of arranging an electrode on a back side of a base material in laser welding of keyhole welding, and forming an electrode with the base material during welding. A DC or AC voltage is applied between the electrodes to generate plasma on the back side of the base material, and the back surface of the base material is heated by the plasma.
【０００６】[0006]
【作用】レーザビームでキーホール溶接をしている際
に、母材と電極間に電圧を印加すると、溶鋼中のＦｅや
シールドガスのＡｒなどがイオン化し、母材と電極間で
プラズマが発生する。したがって、この高温のプラズマ
により母材の裏面を加熱するため、ビード形状が良くな
り、裏ビード幅を拡大するとともに、継手性能が向上す
る。また、電極に溶鋼のスプラッシュが付着したり、板
厚が大となったり、あるいは溶接速度を速くした場合で
も、上記プラズマの発生量はほとんど変化しないため上
記効果を永く保持することができる。[Function] When a voltage is applied between the base material and the electrode during keyhole welding with the laser beam, Fe in the molten steel and Ar in the shielding gas are ionized, and plasma is generated between the base material and the electrode. I do. Therefore, since the back surface of the base material is heated by the high-temperature plasma, the bead shape is improved, the width of the back bead is increased, and the joint performance is improved. Further, even when the molten steel splash adheres to the electrode, when the plate thickness becomes large, or when the welding speed is increased, the above-described effect can be maintained for a long time because the amount of plasma generation hardly changes.
【０００７】[0007]
【実施例】図１は本発明の一実施例を示す説明図であ
り、図中、１，２は突合せ部３を構成する母材、５は突
合せ部３の直下で長手方向に配置した電極、６は母材
１，２と電極５の間に直流または交流の電圧を印加する
ための電源である。母材１，２と電極５の間隔Ｇは１〜
２mmとされる。なお、図示は省略するが、溶接中、母材
１，２の上面側からＡｒなどのシールドガスが吹き付け
られている。図１に示すように、母材１，２と電極５の
間に電圧をかけておき、レーザビーム１０で突合せ部３
をキーホール溶接する。すると、溶鋼中のＦｅやシール
ドガスのＡｒなどがイオン化し、母材１，２と電極５間
でプラズマ１４が発生し、突合せ部３の下部をプラズマ
１４で加熱する。このため、ビード７の形状が図２に示
すようにほぼ上下同幅のものとなり、かつ滑らかにな
る。また、継手７の伸びも後述するように母材なみに向
上し、継手性能が向上する。FIG. 1 is an explanatory view showing an embodiment of the present invention. In the drawings, reference numerals 1 and 2 denote base materials constituting a butt portion 3 and electrodes 5 disposed immediately below the butt portion 3 in a longitudinal direction. , 6 are power supplies for applying a DC or AC voltage between the base materials 1 and 2 and the electrode 5. The gap G between the base materials 1 and 2 and the electrode 5 is 1 to
2 mm. Although not shown, a shielding gas such as Ar is blown from the upper surfaces of the base materials 1 and 2 during welding. As shown in FIG. 1, a voltage is applied between the base materials 1 and 2 and the electrode 5, and
Keyhole welding. Then, Fe in the molten steel, Ar in the shielding gas, and the like are ionized, and plasma 14 is generated between the base materials 1 and 2 and the electrode 5, and the lower part of the butted portion 3 is heated by the plasma 14. For this reason, the shape of the bead 7 becomes substantially equal in the upper and lower widths as shown in FIG. 2 and becomes smooth. Further, the elongation of the joint 7 is improved as much as the base material as described later, and the joint performance is improved.
【０００８】具体的に説明すると、下記のとおりであ
る。 実施例１．図３は溶接速度（ｍ／min ）と継手の全伸び
（％）の実験結果を、本発明と図７の反射板を用いた場
合について比較したものである。実験は下記の条件で行
った。 ａ．母材材料：鋼板（０．７mm厚） ｂ．溶接条件：ＣＯ2 レーザ 出力３ｋｗ ビーム径 ０．２mm ｃ．電 極：銅板 印加電圧 ＡＣ５０Ｈｚ，３０Ｖ ｄ．引張試験：ＪＩＳ Ｚ ２２０１試験片（図４参
照） 図３から明らかなように、母材の伸びが４７％であるの
に対して、本発明では、溶接速度１〜１０ｍ／min にわ
たって継手の伸びは４０％でほとんど変化しなかった。
従来の反射板の場合は低速領域では本発明とほぼ同様の
結果になったが、溶接速度が４ｍ／min 以上になると継
手の伸びが急に低下し始め、８ｍ／min以上では２０％
程度にまで下がって安定した。この理由は、溶接速度が
速くなれば、母材を貫通するビーム量が減り、反射板か
らのビーム反射量が減少するからであり、さらに高速に
なると反射板が無いものと何ら変わらないからである。
一方、本発明の場合、母材と電極間でのプラズマの発生
量は溶接速度と関係なく一定であるため、継手の伸びも
高く保つことができるのである。[0008] The details are as follows. Embodiment 1 FIG. FIG. 3 is a comparison of the experimental results of the welding speed (m / min) and the total elongation (%) of the joint between the present invention and the case of using the reflector of FIG. The experiment was performed under the following conditions. a. Base material: steel plate (0.7 mm thick) b. Welding conditions: CO 2 laser output 3 kw Beam diameter 0.2 mm c. Electrode: Copper plate Applied voltage AC50Hz, 30V d. Tensile test: JIS Z 2201 test piece (see FIG. 4) As is apparent from FIG. 3, while the elongation of the base material is 47%, in the present invention, the elongation of the joint over a welding speed of 1 to 10 m / min. Changed little at 40%.
In the case of the conventional reflector, the result was almost the same as that of the present invention in the low-speed region.
Stable down to about. The reason for this is that if the welding speed increases, the amount of beam penetrating through the base material decreases and the amount of beam reflection from the reflector decreases, and at higher speeds it is no different from that without a reflector. is there.
On the other hand, in the case of the present invention, since the amount of plasma generated between the base material and the electrode is constant irrespective of the welding speed, the elongation of the joint can be kept high.
【０００９】実施例２．図５は溶接回数（回）と裏ビー
ド幅Ａ（mm）の実験結果を、同じく本発明と図７の反射
板を用いた場合について比較したものである。実験は下
記の条件で行ったものである。 ａ．母材材料：鋼板（０．７mm厚） ｂ．溶接条件：ＣＯ2 レーザ 出力３ｋｗ ビーム径 ０．２mm 溶接速度 ５ｍ／min 溶接長 １００mm ｃ．電 極：タングステン 印加電圧 ＡＣ５０Ｈｚ，４０Ｖ 図５から、従来の反射板の場合は、５回程度しか裏ビー
ド幅を拡大する効果がなく、それ以上繰り返し使用する
と、裏ビード幅は次第に減少し始め、１５回では反射板
の無いときと同じく裏ビード幅は０．５mm程度に減少し
た。この理由は、反射板の使用回数が多くなると、溶鋼
のスプラッシュが反射板に付着するため、反射板からの
ビーム反射量が減少するからであり、またスプラッシュ
の付着量がある程度の量に達するとビーム反射量がほと
んど無くなり、反射板の無い場合と同じことになるから
である。これに対して、本発明の場合は、溶鋼のスプラ
ッシュが電極に付着しても母材と電極間でのプラズマの
発生量は一定であるので、理論上は何回使用しても（実
際にはスプラッシュによって母材と電極の短絡が生じる
まで）、裏ビード幅を拡大する効果を持続することがで
きる。Embodiment 2 FIG. FIG. 5 is a comparison of the experimental results of the number of times of welding (times) and the back bead width A (mm) for the case where the present invention and the reflector of FIG. 7 were used. The experiment was performed under the following conditions. a. Base material: steel plate (0.7 mm thick) b. Welding conditions: CO 2 laser output 3 kw Beam diameter 0.2 mm Welding speed 5 m / min Weld length 100 mm c. Electrode: Tungsten Applied voltage AC50Hz, 40V From FIG. 5, in the case of the conventional reflector, there is no effect of expanding the back bead width only about five times, and when it is used repeatedly, the back bead width starts to gradually decrease. At 15 times, the back bead width was reduced to about 0.5 mm as in the case without the reflector. The reason for this is that when the number of times the reflector is used increases, the splash of molten steel adheres to the reflector, and the amount of beam reflection from the reflector decreases, and when the amount of splash adheres reaches a certain amount. This is because there is almost no beam reflection amount, which is the same as when there is no reflector. In contrast, in the case of the present invention, the amount of plasma generated between the base material and the electrode is constant even if the molten steel splash adheres to the electrode. Until the splash causes a short circuit between the base material and the electrode), the effect of increasing the back bead width can be maintained.
【００１０】なお、母材の板厚が変化した場合について
は示してないが、図３及び図５とほぼ同様になることが
これらの結果からも明らかである。Although the case where the thickness of the base material is changed is not shown, it is clear from these results that the result is almost the same as in FIGS.
【００１１】上記実施例では突合せ溶接の場合について
述べたが、本発明は突合せ溶接に限られるものではな
く、レーザービームが母材を貫通する溶接であれば、重
ねシーム溶接、隅肉溶接などにも適用できるものであ
る。In the above embodiment, the case of butt welding has been described. However, the present invention is not limited to butt welding, and is applicable to lap seam welding, fillet welding, and the like as long as the laser beam penetrates the base material. Is also applicable.
【００１２】[0012]
【発明の効果】以上のように本発明によれば、母材と電
極間に発生するプラズマによって母材の裏側を加熱する
ものであるから、継手の形状が良好になり、裏ビード幅
を拡大することができるため開先精度を緩和することが
できるとともに、継手性能を向上することができる。し
かも、溶鋼のスプラッシュが電極に付着しても、あるい
は溶接速度や母材板厚が大となっても、上記プラズマの
発生量はほぼ一定であるため、裏ビード幅の拡大と継手
性能の向上という効果を持続でき、電極の寿命が大巾に
延びる効果が得られる。As described above, according to the present invention, since the back side of the base material is heated by the plasma generated between the base material and the electrodes, the shape of the joint is improved and the width of the back bead is increased. Therefore, the groove accuracy can be reduced, and the joint performance can be improved. Moreover, even if the splash of molten steel adheres to the electrodes, or if the welding speed or base material thickness increases, the amount of plasma generated is almost constant, so the back bead width increases and the joint performance improves. And the effect of extending the life of the electrode can be obtained.
【図１】本発明の一実施例を示す説明図である。FIG. 1 is an explanatory diagram showing one embodiment of the present invention.
【図２】本発明法によるビード断面形状の模式図であ
る。FIG. 2 is a schematic diagram of a bead cross-sectional shape according to the method of the present invention.
【図３】溶接速度と全伸びの関係について本発明法と従
来法を比較した図である。FIG. 3 is a diagram comparing the method of the present invention and the conventional method with respect to the relationship between welding speed and total elongation.
【図４】引張試験片の寸法を示す図である。FIG. 4 is a diagram showing dimensions of a tensile test piece.
【図５】溶接回数と裏ビード幅について本発明法と従来
法を比較した図である。FIG. 5 is a diagram comparing the present invention method and the conventional method with respect to the number of times of welding and the back bead width.
【図６】従来法によるビード断面形状の模式図である。FIG. 6 is a schematic view of a cross-sectional shape of a bead according to a conventional method.
【図７】反射板を用いた従来法の説明図である。FIG. 7 is an explanatory view of a conventional method using a reflection plate.
【図８】ＴＩＧアークによる従来法の説明図である。FIG. 8 is an explanatory diagram of a conventional method using a TIG arc.
１，２ 母材 ３ 突合せ部 ５ 電極 ６ 電源 ７ ビード（継手） １０ レーザビーム １４ プラズマ 1, 2 Base material 3 Butt joint 5 Electrode 6 Power supply 7 Bead (joint) 10 Laser beam 14 Plasma
Claims (1)
接するレーザ溶接において、 母材の裏側に電極を配置し、前記母材と電極間に電圧を
印加することによりレーザビームによるキーホール溶接
に伴ってプラズマを発生させ、このプラズマによって母
材の裏面を加熱することを特徴とするレーザ溶接方法。1. In laser welding in which a laser beam is welded so as to penetrate a base material, an electrode is arranged on a back side of the base material, and a keyhole welding by the laser beam is performed by applying a voltage between the base material and the electrode.
A laser welding method characterized in that a plasma is generated in accordance with the method, and the back surface of the base material is heated by the plasma.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4102904A JP2743699B2 (en) | 1992-04-22 | 1992-04-22 | Laser welding method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4102904A JP2743699B2 (en) | 1992-04-22 | 1992-04-22 | Laser welding method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05293683A JPH05293683A (en) | 1993-11-09 |
| JP2743699B2 true JP2743699B2 (en) | 1998-04-22 |
Family
ID=14339850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4102904A Expired - Fee Related JP2743699B2 (en) | 1992-04-22 | 1992-04-22 | Laser welding method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2743699B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2870766B1 (en) * | 2004-05-26 | 2007-07-20 | Air Liquide | METHOD FOR LASER OR LASER-ARC HYBRID WELDING WITH PLASMA SIDE-SIDE FORMATION |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59110487A (en) * | 1982-12-17 | 1984-06-26 | Inoue Japax Res Inc | Laser working device |
-
1992
- 1992-04-22 JP JP4102904A patent/JP2743699B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH05293683A (en) | 1993-11-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3762676B2 (en) | Work welding method | |
| JP4120408B2 (en) | Laser and arc combined welding method and groove shape of welded joint used therefor | |
| JPH08300172A (en) | Manufacture of welded steel tube | |
| EP1136167A1 (en) | Method for guiding arc by laser, and arc guiding welding and device by the method | |
| JP2743699B2 (en) | Laser welding method | |
| JP2004090069A (en) | Laser-and-arc composite welding method, and groove shape of weld joint used therefor | |
| JP2002144064A (en) | Method and equipment for welding metallic member | |
| JP4470482B2 (en) | Brazing method for lap fillet joints | |
| JP2001198689A (en) | Method of laser welding for aluminum material | |
| JP2001246485A (en) | Laser/arc composite welding equipment | |
| JPS63112088A (en) | Laser beam machining method | |
| JP2004025284A (en) | Laser beam welding method | |
| JP3867164B2 (en) | Welding method | |
| JP2003145270A (en) | Method for terminating consumable two-electrode arc welding | |
| JP2001205465A (en) | Method of composite welding by laser arc and welding equipment | |
| JPH08309567A (en) | Method for welding aluminum alloy | |
| JP2004195528A (en) | Laser irradiation arc welding method of magnesium or magnesium alloy | |
| JP3290627B2 (en) | Voltage applied laser welding method | |
| JPH06285657A (en) | Laser welding process | |
| JP3126791B2 (en) | Butt joining method of plate material and jig used for the joining method | |
| JPH054185B2 (en) | ||
| JPH10263858A (en) | Lap welding method for galvanized steel sheet using laser beam | |
| JP5483553B2 (en) | Laser-arc combined welding method | |
| JPH0562031B2 (en) | ||
| SU1673335A1 (en) | Method of automatic arc butt welding |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080206 Year of fee payment: 10 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090206 Year of fee payment: 11 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100206 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100206 Year of fee payment: 12 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110206 Year of fee payment: 13 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120206 Year of fee payment: 14 |
|
| LAPS | Cancellation because of no payment of annual fees |