FR2658103A1 - Method of welding two clad metal sheets using a laser beam - Google Patents

Method of welding two clad metal sheets using a laser beam Download PDF

Info

Publication number
FR2658103A1
FR2658103A1 FR9002217A FR9002217A FR2658103A1 FR 2658103 A1 FR2658103 A1 FR 2658103A1 FR 9002217 A FR9002217 A FR 9002217A FR 9002217 A FR9002217 A FR 9002217A FR 2658103 A1 FR2658103 A1 FR 2658103A1
Authority
FR
France
Prior art keywords
laser beam
sheet
distance
sheets
welding
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
Application number
FR9002217A
Other languages
French (fr)
Other versions
FR2658103B1 (en
Inventor
Fournier Jean
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Automobiles Peugeot SA
Automobiles Citroen SA
Original Assignee
Automobiles Peugeot SA
Automobiles Citroen SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Automobiles Peugeot SA, Automobiles Citroen SA filed Critical Automobiles Peugeot SA
Priority to FR9002217A priority Critical patent/FR2658103B1/en
Publication of FR2658103A1 publication Critical patent/FR2658103A1/en
Application granted granted Critical
Publication of FR2658103B1 publication Critical patent/FR2658103B1/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/02—Positioning or observing the workpiece, e.g. with respect to the point of impact; Aligning, aiming or focusing the laser beam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/20—Bonding
    • B23K26/32—Bonding taking account of the properties of the material involved
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2101/00—Articles made by soldering, welding or cutting
    • B23K2101/34—Coated articles, e.g. plated or painted; Surface treated articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/08—Non-ferrous metals or alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K2103/00—Materials to be soldered, welded or cut
    • B23K2103/50—Inorganic material, e.g. metals, not provided for in B23K2103/02 – B23K2103/26

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • Laser Beam Processing (AREA)

Abstract

The subject of the present invention is a method of welding two clad metal sheets. According to the invention, in a first step, a test metal sheet (4) is taken whose thickness is equal to the sum of the thicknesses of the two metal sheets (1 and 2) to be welded and whose constituent material is the base metal of these two metal sheets, which is possibly clad with the same material, the laser beam is moved along the test metal sheet (4), the laser beam having been adjusted to the desired parameters for welding, by varying the distance between the metal sheet (4) and the system (3) for focusing the laser beam around the value of the focal length f, this operation is repeated by varying the speed of movement of the laser beam until, for a speed v, a beaded zone (6) is obtained on the reverse side of the test metal sheet (4), and the distance d of the focusing system (3) to the metal sheet (4) is determined at the place where the penetration of the laser beam into the metal sheet (4) is at a maximum. In a second step, the metal sheets are placed in contact with each other beneath the laser beam, and a passage of the laser at the speed v is performed, the focusing system being at the distance d from the external surface of the metal sheet closest to this system.

Description

L'invention concerne le soudage au laser de tôles d'acier revêtues de zinc et, plus généralement, le soudage de tôles revêtues d'un matériau dont la température d'évaporation est inférieure à la température de fusion du métal de base.The invention relates to the laser welding of steel sheets coated with zinc and, more generally, the welding of sheets coated with a material whose evaporation temperature is lower than the melting temperature of the base metal.

Lorsqu'on soude au laser deux tôles d'acier revêtues de zinc, il se forme au niveau du faisceau laser une poche dans laquelle le fer est liquide, mais de la vapeur de zinc est présente dans cette poche. Cette vapeur soulève et expulse le liquide, ce qui conduit à un cordon de soudure irrégulier et ayant de mauvaises qualités mécaniques.When two zinc coated steel sheets are laser welded, a pocket forms in which the iron is liquid at the laser beam, but zinc vapor is present in this pocket. This vapor lifts and expels the liquid, which leads to an irregular weld bead with poor mechanical qualities.

Il est connu, pour éviter cet inconvénient, de ménager un espace entre les tôles afin que la vapeur de zinc puisse s'échapper. Cependant, cela nécessite une préparation des tôles et/ou un appareillage spécial et, dans certains cas, il est souhaitable de laisser les tôles en contact, par exemple si le soudage laser vient en complément d'un autre procédé de soudage. To avoid this drawback, it is known to provide a space between the sheets so that the zinc vapor can escape. However, this requires a preparation of the sheets and / or special equipment and, in certain cases, it is desirable to leave the sheets in contact, for example if laser welding comes in addition to another welding process.

La présente invention a pour objet un procédé de soudage à l'aide d'un faisceau laser de deux tôles revêtues, qui permet de laisser les tôles en contact pendant le soudage au laser.The present invention relates to a welding process using a laser beam of two coated sheets, which allows the sheets to be left in contact during laser welding.

Ce procédé est caractérisé en ce que - dans une première étape on prend une tôle d'essai dont l'épaisseur est égale à la somme des épaisseurs des deux tôles à souder et dont le matériau constitutif est le métal de base de ces deux tôles éventuellement revêtu de la même matière, on déplace le long de la tôle d'essai le faisceau laser réglé aux paramètres désirés pour le soudage, en faisant varier la distance entre la tôle et le système de focalisation du faisceau laser autour de la valeur de la distance focale, on répète cette opération en faisant varier la vitesse de déplacement du faisceau laser jusqu'à ce que, pour une vitesse v, on obtienne une zone perlée sur l'envers de la tôle d'essai, et on détermine la distance d du système de focalisation à la tôle à l'endroit où la pénétration du faisceau laser dans la tôle est maximale;; - et en ce que, dans une seconde étape, on place les tôles au contact l'une de l'autre, sous le faisceau laser et qu'on effectue un passage laser à la vitesse v, le système de focalisation étant à -la distance d de la surface extérieure de la tôle la plus proche de ce système.This process is characterized in that - in a first step, a test sheet is taken, the thickness of which is equal to the sum of the thicknesses of the two sheets to be welded and the constituent material of which is the base metal of these two sheets, if appropriate. coated with the same material, the laser beam adjusted to the desired parameters for welding is moved along the test sheet, varying the distance between the sheet and the laser beam focusing system around the value of the distance focal length, this operation is repeated by varying the speed of movement of the laser beam until, for a speed v, a beaded zone is obtained on the back of the test sheet, and the distance d from the sheet metal focusing system where the penetration of the laser beam into the sheet is maximum; - And in that, in a second step, the sheets are placed in contact with one another, under the laser beam and a laser passage is made at speed v, the focusing system being at -la distance d from the outer surface of the sheet closest to this system.

On entend par "zone perlée" une zone d'aspect irrégulier, où s'est produite une transition de phase liquide-solide et dans laquelle des gouttelettes solidifiées donnent à la surface de la tôle un aspect granuleux et brillant. The term "pearl area" is understood to mean an area of irregular appearance, in which a liquid-solid phase transition has occurred and in which solidified droplets give the surface of the sheet a grainy and shiny appearance.

On a decritci-apres à titre d'exemple non limitatif, un mode de mise en oeuvre du procédé selon l'invention, avec référence au dessin annexé schématique dans lequel:
La Figure 1 montre la première étape du
procédé;
La Figure 2 en montre la seconde étape.There has been described below, by way of nonlimiting example, an embodiment of the method according to the invention, with reference to the appended schematic drawing in which:
Figure 1 shows the first step in
process;
Figure 2 shows the second step.

Pour souder deux tôles revêtues 1 et 2 à l'aide d'un faisceau laser focalisé par une lentille 3 de distance focale f, on commence par prendre une tôle d'essai 4 dont l'épaisseur est égale à la somme des épaisseurs des tôles 1 et 2 et dont le matériau constitutif est le métal de base de ces tôles 1 et 2, éventuellement revêtu de la même matière. On déplace alors le long de la tôle 4 le faisceau laser réglé aux paramètres désirés pour le soudage, en 'faisant varier la distance entre la tôle 4 et la lentille 3 autour de la valeur moyenne f, le point de focalisation 5 du faisceau laser se déplaçant ainsi de part et d'autre de la tôle 4.On répète cette opération en faisant varier la vitesse de déplacement du faisceau laser jusqu'à ce que, pour une vitesse v, on obtienne une zone perlée 6 sur l'envers de la tôle 4, la longueur de cette zone perlée étant de préférence sensiblement égale à la moitié de la longueur du cordon de soudure à réaliser. On mesure la distance d de la lentille 3 à la tôle 4 à l'endroit où la pénétration du faisceau laser dans la tôle est maximale, c'est-à-dire pratiquement au milieu de la zone perlée 6; la détermination de cet endroit peut se faire par tout moyen connu, par exemple par observation visuelle, à l'aide d'un palpeur ou en déterminant le rayonnement maximal émis par la face arrière de la tôle à l'aide d'une photodiode.To weld two coated sheets 1 and 2 using a laser beam focused by a lens 3 of focal length f, we start by taking a test sheet 4 whose thickness is equal to the sum of the thicknesses of the sheets 1 and 2 and whose constituent material is the base metal of these sheets 1 and 2, possibly coated with the same material. The laser beam adjusted to the desired parameters for welding is then moved along the sheet 4, varying the distance between the sheet 4 and the lens 3 around the average value f, the focal point 5 of the laser beam thus moving on either side of the sheet 4. We repeat this operation by varying the speed of movement of the laser beam until, for a speed v, we obtain a beaded area 6 on the back of the sheet 4, the length of this beaded area being preferably substantially equal to half the length of the weld bead to be produced. The distance d from the lens 3 to the sheet 4 is measured at the point where the penetration of the laser beam into the sheet is maximum, that is to say practically in the middle of the beaded area 6; the determination of this location can be done by any known means, for example by visual observation, using a probe or by determining the maximum radiation emitted by the rear face of the sheet using a photodiode.

Il ne reste plus qu'à placer les tôles 1 et 2 au contact l'une de l'autre sous le faisceau laser et à effectuer un passage laser à la vitesse v, la lentille 3 étant à la distance d de la surface extérieure de la tôle 1 la plus proche de cette lentille.It only remains to place the sheets 1 and 2 in contact with each other under the laser beam and to carry out a laser passage at speed v, the lens 3 being at the distance d from the outer surface of the sheet 1 closest to this lens.

Lors de la mise en oeuvre de ce procédé, on prévoit un poste d'essai où se trouve un analyseur permettant de déterminer la position du milieu de la zone perlée, et un poste de soudure où est prévu un dispositif de mesure de la distance entre la lentille 3 de la source laser et la surface de la première tôle 1. Lorsqu'on soude les deux tôles 1 et 2 à l'aide du faisceau laser, il se forme au niveau de âelui-ci une cavité appelée "keyhole" qui présente une zone gazeuse entourant immédiatement le faisceau et une zone liquide entourant cette zone gazeuse. La distance d correspond à la position du faisceau pour laquelle la zone gazeuse traverse les deux tôles de part en part, ce qui permet l'évacuation des vapeurs de zinc.During the implementation of this process, there is provided a test station where there is an analyzer making it possible to determine the position of the middle of the beaded area, and a welding station where a device for measuring the distance between the lens 3 of the laser source and the surface of the first sheet 1. When the two sheets 1 and 2 are welded using the laser beam, a cavity called "keyhole" is formed at the latter. has a gas zone immediately surrounding the beam and a liquid zone surrounding this gas zone. The distance d corresponds to the position of the beam for which the gas zone crosses the two sheets from side to side, which allows the evacuation of zinc vapors.

Il va de soi que la présente invention ne doit pas être limitée au mode de mise en oeuvre décrit et représenté, mais en couvre, au contraire, toutes les variantes. Par exemple, la distance d peut être asservie à un capteur optoélectronique qui mesure l'émission de la face arrière de la deuxième tôle 2, ce qui permet de piloter le procédé en temps réel pour s'affranchir de certains défauts des tôles, par exemple d'une variation d'épaisseur. On peut encore, en particulier si cet asservissement n'est pas possible (cas des corps creux), faire osciller le système de focalisation ou la valeur de distance focale (par exemple en modifiant la courbure d'un miroir) à une fréquence suffisamment élevée (par exemple 1000 Hz) pour que des défauts n'aient pas le temps de se créer, l'amplitude de l'oscillation étant déterminée en fonction de l'incertitude de l'asservissement en position du système de focalisation par rapport aux tôles et en fonction des tolérances dimensionnelles de celles-ci. It goes without saying that the present invention should not be limited to the embodiment described and shown, but on the contrary covers all variants. For example, the distance d can be controlled by an optoelectronic sensor which measures the emission from the rear face of the second sheet 2, which makes it possible to control the process in real time to overcome certain sheet faults, for example of a thickness variation. It is also possible, in particular if this enslavement is not possible (case of hollow bodies), to oscillate the focusing system or the focal distance value (for example by modifying the curvature of a mirror) at a sufficiently high frequency. (for example 1000 Hz) so that defects do not have time to be created, the amplitude of the oscillation being determined as a function of the uncertainty of the servo-control in position of the focusing system with respect to the sheets and according to their dimensional tolerances.

Claims (4)

RevendicationsClaims 1. Procédé de soudage de deux tôles revêtues, caractérisé en ce que - dans une première étape on prend une tôle d'essai (4) dont l'épaisseur est égale à la somme des épaisseurs des deux tôles à souder (1 et 2) et dont le matériau constitutif est le métal de base de ces deux tôles éventuellement revêtu de la même matière, on déplace le long de la tôle d'essai (4) le faisceau laser réglé aux paramètres désirés pour le soudage, en faisant varier la distance entre la tôle (4) et le système de focalisation (3) du faisceau laser autour de la valeur de la distance focale f, on répète cette opération en faisant varier la vitesse de déplacement du faisceau laser jusqu'à ce que, pour une vitesse v, on obtienne une zone perlée (6) sur l'envers de la tôle d'essai (4), et on détermine la distance d du système de focalisation (3) à la tôle (4) à l'endroit où la pénétration du faisceau laser dans la tôle (4) est maximale; - et en ce que, dans une seconde étape, on place les tôles au contact l'une de l'autre, sous le faisceau laser et qu'on effectue un passage laser à la vitesse v, le système de focalisation étant à la distance d de la surface extérieure de la tôle la plus proche de ce système.1. Method for welding two coated sheets, characterized in that - in a first step, a test sheet (4) is taken, the thickness of which is equal to the sum of the thicknesses of the two sheets to be welded (1 and 2) and of which the constituent material is the base metal of these two sheets optionally coated with the same material, the laser beam adjusted to the desired parameters for welding is moved along the test sheet (4), varying the distance between the sheet (4) and the focusing system (3) of the laser beam around the value of the focal distance f, this operation is repeated by varying the speed of movement of the laser beam until, for a speed v, we obtain a beaded zone (6) on the back of the test sheet (4), and we determine the distance d from the focusing system (3) to the sheet (4) at the point where the penetration laser beam in the sheet (4) is maximum; - And in that, in a second step, the sheets are placed in contact with each other, under the laser beam and a laser passage is made at speed v, the focusing system being at the distance d of the outer surface of the sheet closest to this system. 2. Procédé selon la revendication 1, caractérisé en ce qu'on détermine la distance d à l'endroit situé sensiblement au milieu de la zone perlée. 2. Method according to claim 1, characterized in that the distance d is determined at the place located substantially in the middle of the beaded area. 3. Procédé selon l'une quelconque des revendications 1 et 2, caractérisé en ce que la distance d est asservie à un capteur optoélectronique qui mesure l'émission de la face arrière de la deuxième tôle (2).3. Method according to any one of claims 1 and 2, characterized in that the distance d is controlled by an optoelectronic sensor which measures the emission from the rear face of the second sheet (2). 4. Procédé selon l'une quelconque des revendications 1 et 2, caractérisé en ce qu'on fait osciller le système de focalisation (3) ou la valeur de la distance focale. 4. Method according to any one of claims 1 and 2, characterized in that the focusing system (3) or the value of the focal distance oscillates.
FR9002217A 1990-02-15 1990-02-15 METHOD OF WELDING USING A LASER BEAM OF TWO COATED SHEETS. Expired - Fee Related FR2658103B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR9002217A FR2658103B1 (en) 1990-02-15 1990-02-15 METHOD OF WELDING USING A LASER BEAM OF TWO COATED SHEETS.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR9002217A FR2658103B1 (en) 1990-02-15 1990-02-15 METHOD OF WELDING USING A LASER BEAM OF TWO COATED SHEETS.

Publications (2)

Publication Number Publication Date
FR2658103A1 true FR2658103A1 (en) 1991-08-16
FR2658103B1 FR2658103B1 (en) 1994-11-04

Family

ID=9394037

Family Applications (1)

Application Number Title Priority Date Filing Date
FR9002217A Expired - Fee Related FR2658103B1 (en) 1990-02-15 1990-02-15 METHOD OF WELDING USING A LASER BEAM OF TWO COATED SHEETS.

Country Status (1)

Country Link
FR (1) FR2658103B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0538087A1 (en) * 1991-10-18 1993-04-21 Sollac Method for laser beam welding coated metal sheets
EP1075891A2 (en) * 1999-07-19 2001-02-14 Sumitomo Electric Industries, Ltd. Laser welding method

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN *
WELDING AND METAL FABRICATION *
WELDING PRODUCTION *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0538087A1 (en) * 1991-10-18 1993-04-21 Sollac Method for laser beam welding coated metal sheets
FR2682627A1 (en) * 1991-10-18 1993-04-23 Lorraine Laminage METHOD FOR LASER BEAM WELDING OF TWO COATED SHEETS.
EP1075891A2 (en) * 1999-07-19 2001-02-14 Sumitomo Electric Industries, Ltd. Laser welding method
EP1075891A3 (en) * 1999-07-19 2004-03-17 Sumitomo Electric Industries, Ltd. Laser welding method

Also Published As

Publication number Publication date
FR2658103B1 (en) 1994-11-04

Similar Documents

Publication Publication Date Title
US20060011592A1 (en) Laser welding control
JP6220718B2 (en) Laser welding quality determination method and laser welding quality determination device
FR2575686A1 (en) HIGH FREQUENCY WELDING METHOD USING ELECTRIC RESISTANCE USING LASER BEAM EXPOSURE
EP1591187B1 (en) Process for welding coated sheet metal by means of an energy beam, such as a laser beam
CN108778607B (en) Laser welding steel with power modulation to avoid hot cracking
FR2910621A1 (en) Controlling the quality of welding cord produced by a tool, comprises collecting a signal representing fusion temperature of portion of welding cordon, and treating and analyzing the signal to identify possible defects in the welding cord
JP2001191187A (en) Method and device for measuring process parameter in material working process
Kratzsch et al. Coaxial process control during laser beam welding of tailored blanks
FR2658103A1 (en) Method of welding two clad metal sheets using a laser beam
EP0520894B1 (en) Welding head for measuring welding parameters and method of use
RU2194601C2 (en) Method for controlling welded joint
JP3169354B2 (en) Laser welding monitoring system
JPH081361A (en) Laser beam cladding device and its method for controlling position of irradiation
US4859830A (en) Method of determining the weldability of a part
JP6559604B2 (en) Laser ultrasonic measuring apparatus, laser ultrasonic measuring method, welding apparatus and welding method
RU2000124878A (en) WELD CONTROL METHOD
EP0006389B1 (en) Process and device for the automatic tracking of welding joints
FR2682627A1 (en) METHOD FOR LASER BEAM WELDING OF TWO COATED SHEETS.
FR2973725A1 (en) Drilling and cutting metallic material by laser beam by subjecting metal material to impact of laser beam to operate onset of melting localized from material, and continuing localized melting of material started in subjecting step
JP3621755B2 (en) Underwater laser welding method
FR2560089A1 (en) Method and device for controlling an arc-welding operation
Kamimuki et al. Development of monitoring method for YAG laser welding and its application. Study of monitoring technology for YAG laser welding
JP3281959B2 (en) Weld inspection method
EP0591400A1 (en) Welding machine having automatic penetration-related control
CA2495566A1 (en) Device and method for controlling an operation involving the laser beam welding, hardfacing or machining of a part

Legal Events

Date Code Title Description
ST Notification of lapse