JP2002263870A - Apparatus and method for producing butt-welded steel plate or steel strip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize stable continuous welding when butt-welding a plurality of steel plates or steel strips having different thicknesses, strengths, different cross-sectional areas or properties by a laser beam at an end thereof. To provide an apparatus and method. SOLUTION: A plurality of steel sheets or steel strips 1 and 2 have a roll body length longer than their full width, and a welding roller 3 installed at an angle to a direction perpendicular to the traveling direction thereof; On the upper side, a laser beam welding machine 9 is provided, and pressing devices 7, 7 for pressing a steel plate or a steel strip to be welded from above are provided above and below the welding roller 3 before and after the laser beam welding machine 9, and the steel plate or the steel strip is provided. A side guide 4 that guides an edge portion on a side on which a pressing force acts in a direction perpendicular to a traveling direction of a steel plate or a steel strip on a side opposite to the butt seam portion 6;
5 is provided before and after the welding roller 3, and a heating device 10 for performing heat treatment on the butt seam portion 6 is provided behind the laser beam welding machine 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus and a manufacturing method for performing butt welding of a plurality of steel plates or steel strips having different thicknesses, strengths, or properties by using a laser beam at a longitudinal end thereof. It is.

[0002]

2. Description of the Related Art As a method of continuously butting steel sheets, a method has been proposed in which a steel sheet or a steel strip is conveyed while being continuously butted, and welding is performed with a fixed torch. In order to butt-join a steel plate or a steel strip continuously in the longitudinal direction using a laser beam, these plate ends are butted with no gap, and the butt seam position is guided within a certain allowable range with respect to the laser beam irradiation position. Needed. Also, in the above method,
Because the heat affected zone generated by performing welding with a laser torch is hardened with respect to the material before processing, workability as a product will be restricted,
There is a problem that restrictions are imposed on the application or the molded shape.

As a technique for solving these problems, a continuous welding method is disclosed in Japanese Patent Application Laid-Open No. 2000-15816.
In No. 3, the plurality of steel strips are passed between a welding roller and a plurality of holding rollers arranged in an inclined manner,
A welding method of performing laser welding while applying a force in the width direction to a steel strip so as to apply a pressing force to an edge end of a different steel strip has been proposed.

However, in this method, since the inclined holding roller has a smaller diameter than a large roller, the butt seam position is unstable due to the influence of the surface roughness of the steel strip and the state of oiling, and the continuous pressing is continuously performed. The problem is that stable welding cannot be achieved, and when joining steel sheets or steel strips with greatly different cross-sectional areas, the welding heat generated by welding causes the steel strip to bend in a plane, so the butt seam position Has become unstable.

Further, regarding the material hardening after welding, when laser welding is performed by abutting the edges of a steel plate or a steel strip, portions that have been melted, joined, and cooled by laser welding are locally localized due to heat. As compared with the material, in the width direction, it is hardened about 2-3 times in the area of about 2-3 times the plate thickness. For this reason, when using products manufactured by the above method, there is a restriction that the welded part should be used so as not to cause large plastic deformation or that the application method should be considered in advance and the joining method of the steel plate or steel strip should be considered. Was.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a steel plate or a steel strip having a different cross-sectional area when a plurality of steel plates or steel strips having different thicknesses, strengths or properties are butt-welded at their ends by a laser beam. About the obi
It is an object of the present invention to provide an apparatus and a method capable of realizing stable continuous welding. Further, a plurality of steel sheets or steel strips having different thicknesses, strengths, or properties are formed by a laser beam at an end thereof. It is an object of the present invention to provide an inexpensive and widely applicable steel sheet manufacturing apparatus and method by manufacturing a homogeneous product without losing the material properties before processing after performing butt welding by the method. is there.

[0007]

The gist of the present invention is as follows: (1) In an apparatus for butt-joining the edges of a plurality of steel plates or strips by a laser beam, the entire width of the plurality of steel plates or strips is determined. Roller body length is longer, with a welding roller installed at an angle to the direction perpendicular to its traveling direction, and a laser beam welding machine on the circumference of the welding roller, and the steel plate or steel strip to be welded is lifted upward. A pressing device for pressing from above is provided before and after the laser beam welding machine above the welding roller, and on the side opposite to the butt seam portion of the steel plate or the steel strip, the edge on the side on which the pressing force acts in the direction perpendicular to the traveling direction of the steel plate or the steel strip. Characterized in that a side guide for guiding the welding portion is provided before and after the welding roller, and a heating device for performing heat treatment on the butt seam portion is provided. Equipment for manufacturing contacted steel plates or strips. (2) In a method of butt-joining the edges of a plurality of steel plates or strips by a laser beam, the plurality of steel plates or strips are rolled longer than their full width,
With respect to the direction perpendicular to the traveling direction, the steel plate or the steel strip to be welded at the time of welding with a laser beam welding machine on the circumference of the welding roller by passing over a welding roller installed at an angle is welded. While pressing from above the welding roller before and after the point, and butt-welding while guiding the edge on the side where the pressing force works on the side opposite to the butt seam part of the steel sheet or steel strip before and after the welding roller, the steel sheet Alternatively, a method for producing a butt-welded steel plate or steel strip, comprising subjecting a butt seam portion of the steel strip to heat treatment. It is in.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Based on an embodiment of the present invention in butt welding two steel strips shown in FIGS.
The present invention will be described in detail. Fig. 1 and Fig. 2
In the direction indicated by arrow 12 in FIG. The present invention, as described above, is a method and apparatus for continuously joining the edges of steel plates or steel strips having different materials and thicknesses, and thereafter performing heat treatment on the edges of the steel plates or steel strips. As a device for positioning the steel plate or the steel strips 1 and 2 at the time of joining, the roll body length is longer than the entire width of the device,
The present invention has a welding roller 3 installed at an angle to the direction perpendicular to the traveling direction, and a laser beam welding machine 9 on the circumference of the welding roller.

The inclination angle (α in FIG. 1) of the welding roller 3 is:
If it is too small, the pressing force between the steel sheets or steel strips becomes insufficient, and the behavior of the steel sheets becomes unstable. Therefore, it is preferable that the angle is 0.1 degree or more with respect to the direction perpendicular to the traveling direction of the steel sheets or steel strips. In this case, the steel strip is pressed by excessive force on the side guide, and the steel strip edge is bent.

Further, the apparatus of the present invention comprises a pressing device 7 for pressing a steel plate or a steel strip 1 or 2 to be welded from above,
7 is provided before and after the laser beam welding machine 9 above the welding roller 3, and a pressing force (FIG. 1, side guides 4 and 5 are provided before and after the welding roller 3 on the downstream side of the welding roller to guide the edge portion on the side on which the force (in the upward direction in the drawing) that is parallel to the axis of the welding roller acts. The pressing pressure is 1500 determined by the thickness, width, and material of the material to be welded.
It is preferable to apply a force of about N to 10,000 N.

According to the present invention, a steel sheet or a steel strip generated by heat input by welding is changed by changing the pressing force applied by the pressing devices 7 and 7 with the progress of welding and combining the side guides 4 and 5 with each other. It is preferable to stabilize the welding operation by correcting the bending of the welding operation. In addition, when the cross-sectional area of the two materials to be welded greatly differs by more than twice, the pressing force differs by about 2 to 10 minutes because the appropriate pressure at the start of welding and after a certain time differs due to bending of the steel strip. It is preferable that the pressure after the predetermined time is obtained by increasing the pressing force at the start of welding by about 20 to 30%.

If the appropriate value of the pressing force is too large or too small, a phenomenon similar to the inclination angle of the welding roller occurs. From this viewpoint, the same effect can be achieved by controlling the position or pressure of the welding roller, the holding roller, the side guide, and the like constituting the pressing force as the welding progresses, but a means for changing the pressure of the holding roller is used. For the simplicity, the conditions using the means are described as the above recommended conditions.

Further, according to the present invention, it is possible to manufacture a homogeneous product by performing a heat treatment on the steel sheet or the steel strips 1 and 2 after the bonding, performing an annealing treatment on the materials to be bonded, and restoring the material characteristics before the processing. It is also unique in that For the product after welding, the hardened part is heated by a heat treatment device such as induction heating, electric current heating, laser electron beam, gas / liquid combustion, etc. so that the material is in the state before processing, and then slowly cooled as necessary To reduce the heat affected zone generated by laser welding.

At this time, the heating and slow cooling performed on the steel sheet or the steel strip after the joining is not performed on the entire area in the width direction. This is because the base material not affected by heat is
Due to the heat treatment, the grain size of the material grows,
This is because the workability and the surface appearance are impaired, and it is preferable to selectively perform the process only on the region affected by the heat due to the joining.

The temperature applied to the steel sheet or the steel strip after joining is a temperature for tempering bainite or martensite structure in the weld metal as a material-specific recovery temperature. 300 in case
It is desirable to perform the process at about 700 ° C. Depending on the use of the steel material, the required surface appearance, and the mechanical properties,
It is necessary to appropriately select a means for performing the heat treatment.

When the edges of a steel plate or a steel strip are butt-welded and laser-welded, if a gap is formed in the butt seam, poor quality such as an undercut is likely to occur in the welded portion. However, when a steel sheet or a steel strip is usually manufactured, since a shearing process such as slitting, trimming, or shearing is performed, unevenness remains at an end portion of the workpiece. When these end faces are butted, a gap is generated.Moreover, at the time of laser welding, the force to open the butted portion further due to welding thermal deformation and the large cross-sectional area when joining steel sheets or steel strips having different cross-sectional areas. Due to the occurrence of bending on the material side, the gap of the welded seam is enlarged and the welding position is shifted, so that stable continuous welding of a steel sheet or a steel strip having various cross-sectional areas has been impossible. Furthermore, as for the product after welding, as described above, the welded portion is hardened, so that it is necessary to limit the scope of the product.

In the present invention, the welding roller is inclined with respect to the traveling direction of the steel sheet or the steel strip to apply a butt force to the edge of the steel sheet or the steel strip. More preferably, the butt force is applied for a predetermined time from the welding start time. By changing over time, the unevenness of the end of the material, the gap caused by thermal deformation, and the displacement caused by thermal deformation are reduced, thereby ensuring stable welding quality. .

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In this embodiment, the apparatus is used to join two steel strips 1 and 2. However, the present invention is also effective when three or more steel strips 1, 2, and 1 are joined at one time as shown in FIG. It is. Low carbon steel strips (C = 0.01%) 1 and 2 each have a thickness x width of 0.7 mm x 500 mm, 2.3 mm x 50
The thing of 0 mm was used. The steel strips 1 and 2 were wound and conveyed around the welding roller 3, and the welding roller was installed at an angle (α = 0.3 degrees) with respect to the traveling direction of the steel strip. The side guides 4 and 5 are fixed plate-shaped side guides, and the pressing force of the pressing roller was set to 5000 N at the start of welding and changed to 7500 N after 3 minutes.

When the welding material was passed at a speed in the range of 2 to 10 mpm, the butt opening could be controlled to 0.1 mm or less and the displacement of the butt seam could be controlled to ± 0.2 mm or less. Then, in the butt seam portion 6,
At the welding point 8 on the circumference of the welding roller, a laser beam 9 was irradiated to perform butt welding. FIG. 2 shows FIG.
In the present embodiment, the pressing force is determined by the pressing force cylinder 11 of the pressing roller 7.
Was performed by changing the rolling force.

FIG. 3 shows another embodiment in which three steel strips 1, 2, 1 are joined. Further, the butt seam portion 6 of the steel strip is heated by the heating device 10 installed after the welding, and the heat treatment is performed. Heating device 1
As 0, the high-frequency induction heating device was used to heat the butt seam (area of 10 mm in width between the welding line and the welding line) 1000 mm behind the welding point 8, and to measure the steel strip temperature history measured by a thermocouple embedded in the steel strip. As shown in FIG. By heating at 500 ° C for 1 second, Vickers hardness Hv80 before welding was changed to Vickers hardness Hv200 when there was no heating after welding. It was possible to improve the Vickers hardness Hv80 and the condition before welding, confirming the effectiveness of the present invention.

[0021]

According to the present invention, the range of combinations of butt-welded plates can be expanded, and furthermore, it is possible to produce a steel sheet or a steel strip of good quality with a uniform mechanical property value of the welded portion.
It can be manufactured at low cost and with high productivity.

[Brief description of the drawings]

FIG. 1 is a plan view of a manufacturing apparatus that is an example of the present invention.

FIG. 2 is a side view of the apparatus of the present invention shown in FIG.

FIG. 3 is a plan view of a manufacturing apparatus as an example of the present invention when three steel sheets or steel strips are simultaneously welded.

FIG. 4 is 1 mm from a butt portion of a steel plate according to the present invention.
FIG. 5 is a diagram showing a temperature history of a portion of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 2 Steel plate or steel strip 3 Welding roller 4 Side guide 5 Side guide 6 Attached seam part 7 Pressing device (pressing roller) 8 Welding point 9 Laser beam welding machine 10 Heating device 11 Cylinder for pressing force 12 Material passing direction

Claims (2)

[Claims] An apparatus for butt-joining a plurality of steel plates or steel strip edges by a laser beam,
The roll body length is longer than the entire width of the plurality of steel sheets or steel strips, and a welding roller that is installed inclined with respect to a direction perpendicular to the traveling direction thereof, and has a laser beam welding machine on the circumference of the welding roller, A pressing device for pressing a steel plate or a steel strip to be welded from above is provided before and after the laser beam welding machine above the welding roller, and on a side opposite to a butt seam portion of the steel plate or the steel strip, a traveling right angle of the steel plate or the steel strip. Butt welding characterized by providing side guides for guiding an edge portion on a side where a pressing force acts in the direction before and after the welding roller, and a heating device for performing heat treatment on the butt seam portion is provided behind the laser beam welding machine. Equipment for the production of thinned steel sheets or strips. 2. A method for butt joining a plurality of steel plates or steel strip edges by a laser beam,
A plurality of steel plates or strips are passed over a welding roller whose roll body length is longer than their full width and which is inclined with respect to the direction perpendicular to the traveling direction, and a laser beam is formed on the circumference of the welding roller. When welding with a welding machine, press the steel plate or steel strip to be welded from above the welding roller before and after the welding point, and on the side opposite to the butt seam part of the steel plate or steel strip, where the pressing force acts. A method for producing a butt-welded steel plate or steel strip, comprising performing butt welding while guiding an edge portion before and after a welding roller, and then subjecting the butt seam portion of the steel plate or steel strip to heat treatment.